During the COVID-19 pandemic in 2020, a number of international cruise ships were infected, thereby resulting in serious public health and human rights problems. Multiple difficulties were encountered in the prevention and control of the coronavirus disease onboard ships, while rule-based international cooperation in this regard appeared inefficient and ineffective. By applying interdisciplinary methodologies, including empirical research of law, policy science, and health studies, this research reviewed the legal difficulties in the prevention and control of COVID-19 on international cruise ships and sought solutions from a policy-making and strategic perspective. We found that, apart from the inherent nature of cruise ships such as crowded semi-enclosed areas, shared sanitary facilities and limited medical resources, there are also nonnegligible legal reasons affecting the effectiveness of containment measures on board. In particular, there is ambiguity and even inconsistency of relevant international norms and domestic regulations, and some of the key rules are neither mandatory nor enforceable. We conclude by suggesting that rule-based international cooperation on this issue must be strengthened with respect to information sharing and management, a more effective supervisory mechanism, clarification of key rules over jurisdiction and distributions of obligations among the port states, flag states, nationality states, and cruise ship companies. International cruise tourism is the fastest growing sector of the travel industry since the early 1990s. Statistics show that in the past decade, cruising around the world has continued to boom with an average annual growth rate of 6.8 percent, and it was estimated that in 2020 the global ocean cruise industry would carry over 32 million passengers .Outbreaks of COVID-19 on international cruise ships attracted worldwide concern not only from stakeholders including cruise lines and national governments but also from researchers and the public. As a matter of fact, due to the inherent features of cruise ships such as the high population density, shared food supplies, and semi-enclosed living environments, the spread of infectious diseases occurs relatively easily on board . There iMS Westerdam cruise ship is a typical case in point. After departing from Hong Kong with 1455 passengers and 802 crew members on 1 February 2020, because of suspected coronavirus cases on board, the ship was denied entry not only by its destination port of Yokohama but also by other nearby ports in Japan, South Korea, Guam, Thailand, and the Philippines. On 13 February 2020, the ship was finally accepted by Sihanoukville Port in Cambodia, ending its two weeks’ helplessly drifting at sea. From a legal perspective, do these states have the right to deny entry? Which state is obligated to provide assistance in a public health emergency? If an infected ship is permitted to dock and disembark passengers, what measures can the port state take under its governing laws? How can it be ensured that all involved parties, including the flag state, the coastal state, and the ship operator/owner’s state, will cooperate effectively in the face of a global pandemic? All these issues are important for international cruise ships to prevent and control the on-going COVID-19 pandemic. However, they largely remain unclear and even unanswered. Existing literature and research mainly focus on textual interpretation of relevant legal provisions under normal circumstances, but without concurrently taking into account the unique features of international cruise ships. Much less is discussed under the on-going COVID-19 pandemic circumstance, which have brought upon unprecedented new challenges to the whole world.Both the prevention and the control of infectious diseases on cruise ships are relatively more complicated and problematic, especially for those international ships with passengers of different nationalities and docking ports located in different countries. Apart from the limited healthcare and medical conditions onboard, there are also difficulties with respect to the rule-based international cooperation and coordination of treatment measures. During the first wave of the COVID-19 pandemic, a number of international cruise ships were denied from docking or entering into the costal ports, as states applied different, changing, and sometimes even conflicting rules. The Holland America Against this backdrop, this research article aims to analyze the international regulatory issues relating to the prevention and control of epidemics on international cruise ships, with a special focus on investigating those legal mechanisms from the perspective of strategies and policies of epidemic prevention and control. Regarding the facts about outbreaks of the COVID-19 pandemic on international cruise ships, relevant information and data were collected mainly through the official websites of involved institutions, such as the International Maritime Organization (IMO), the International Cruise Line Association (ICLA), and other public sources such as Wikipedia and international news reports. The searching period for the factual data is set between January 2020 and December 2020.For policies and strategies of COVID-19 prevention and control on cruise ships, research materials and data were collected mainly through relevant governmental departments, such as Japan’s Ministry of Health, Labour and Welfare, China’s National Health Committee and Maritime Safety Administration, and the United States Centers for Disease Control and Prevention (CDC) as well as its Vessel Sanitation Program (VSP). For academic analysis and discussions of these policies and strategies, research literature and references were obtained by searching databases such as PubMed, Medline, and Embase using keywords cruise ships, infectious disease, COVID-19, travel health, ship sanitation, and PHEIC.For research questions on the governing laws and precedent cases, such as the interpretation and application of relevant provisions of the United Nations Convention on the Law of the Sea (UNCLOS), the WHO’s International Health Regulations (IHR), and the IMO’s Guidelines on Places of Refuge for Ships in Need of Assistance, references were acquired by searching Heinonline, Westlaw, LexisNexis and other professional legal databases.Interdisciplinary methodologies including empirical research of law, policy science, and health studies were adopted. The comprehensive search and literature review of COVID-19 cases that are linked to cruise ships were conducted so as to provide a strong basis for empirical analysis and further discussions. Past public health incidents on international cruise ships during other pandemics such as SARS and MERS are also referred to. Based on findings of these facts, the actual effects of relevant rule-based mechanisms on tackling cruise ships’ public health emergencies are evaluated. These empirical studies will facilitate our understanding on the functioning of relevant legal regime and its impact on the formulation of pandemic control policies in the face of the COVID-19.Doctrinal research, named “black letter” methodology, is fundamental to the study of legal issues. We will identify, describe, and critically analyze the text of relevant legal provisions contained in the UNCLOS, the IHR, and other relevant international conventions, as well as relevant domestic regulations of Japan, the United States, and other countries. The aim of textual analysis is to explore the original intention of legislation and identify ambiguities, inefficiencies, and even inconsistencies in relevant rules, based on which improvement suggestions and solutions are provided.Case studies are also important for this research. We particularly focused on those representative cases such as the Diamond Princess cruise ship, which is considered a de facto epidemiological laboratory during the first wave of COVID-19 outbreaks in 2020. Lessons learned from this high-profile case are worth carefully studying in terms of strengthening rule-based international cooperation and improving health conditions on future cruise ships in similar pandemic situations. Major questions of these case studies include emerging regulatory issues encountered by various parties, whether and to what extent they are liable, whether their measures comply with relevant international and national norms and whether the right to health of people on board is sufficiently protected.Through data retrieval and analysis, we found that there was a COVID-19 pandemic outbreak on nearly 50 international cruise ships. A number of typical cases are listed in The factors resulting in the difficulties of COVID-19 prevention and control on international cruise ships, apart from those inherent physical circumstances such as close living and working conditions and medical treatment restrictions on board, we found that the inadequacy and even failure of cooperation by involved parties were incredibly salient. The WHO has indicated that health on international cruise ships is a shared responsibility of all relevant stakeholders, involving equitable access to essential care and collective defense against transnational threats . In termWe further found complicated legal motivations, as all measures and cooperation are rule-based. A large number and variety of laws and regulations, both national and international, are applicable to the issue of prevention and control of COVID-19 on international cruise ships. The UNCLOS, the foremost international agreement on law of the sea, for example, provides rules including the general obligation of maritime rescue and cooperation, jurisdiction of port states and flag states. Meanwhile, more substantial regulations on the management of ships and ports, entry and exit control, and health and quarantine requirements are contained and scattered in other international and national laws of the countries involved. In this regard, we discovered that there are certain ambiguity and even inconsistency with regard to the relevant international norms and the domestic regulations of individual states. Such a lack of regulatory harmony directly led to problems of conflicted jurisdictions, unbalanced liabilities, and an uncertainty of rescue obligations during the COVID-19 pandemic.Moreover, some key rules are not enforceable or mandatory. For example, in order to cope with coastal states’ prohibition of environmentally threatening foreign ships from entering their ports, the IMO passed two resolutions to address the issue of places of refuge for ships in distress: the Guidelines on Places of Refuge for Ships in Need of Assistance  and the As a general principle, according to the IHR, a country shall grant ships the right of free pratique; that is, ships shall not be prevented from calling at any point of entry for public health reasons . This isA limitation to the free pratique principle is that, when infection or contamination sources are found on board, a country may require disinfection, decontamination, disinsection or deratting, or other necessary measures that should be taken to prevent the spread of the infection or contamination . The IHRThough the UNCLOS allows costal states to deny a foreign ship’s right of innocent passage in their territorial waters and prohibit ships from entering for sanitary reasons , some shFrom a legal perspective, when a pandemic outbreak occurs on board and an international cruise ship needs to be rescued, the first thing to ascertain is which country has an obligation to rescue. The UNCLOS stipulates two major types of maritime states: the coastal states and the port states . AccordiThere are virtually two types of port states: one involves a cruise ship that has already entered the port, and the other involves a scheduled port of call without entering. In the latter case, according to relevant provisions of the IHR , if the The rescue obligations of coastal and port states have limitations. Under the UNCLOS, the rescue obligation primarily concerns dangerous situations such as typhoons and collisions at sea, under which circumstances the nearby ships are obliged to render assistance when a cruise ship calls for rescue in international waters. The COVID-19 pandemic, whereas, is somewhat different from those circumstances. When a pandemic occurs, not only does the cruise ship require special treatment, but the rescuers, including the port states, also need to consider whether they have the necessary capability to prevent and control infectious disease. This is particularly the case in the early stages of the COVID-19 outbreak when many things were unknown in terms of transmission, containment, and treatment. It would be unjustified to request a costal or port state to undertake rescue obligations while putting its own people at risk. Therefore, in the case of the Westerdam cruise ship, Guam refused to rescue by stating that it had limited resources to “screen, quarantine, or treat 1400 patients at one time”, and its “obligation [was] to protect the people of Guam” first . Other pUnder UNCLOS, innocent passage through territorial sea is an important right of all ships, as long as it is not prejudicial to the peace, good order, or security of the coastal state . As a baIf a ship may bring about serious safety threats, costal states are inclined to refuse its entry. Environmental pollution excuses are mostly seen in the past. For example, in November 2002, when the Greek-operated oil tanker MV Prestige carrying 77,000 tonnes of heavy fuel oil was in danger while passing through the waters near Spain, not only the Spanish but the French and Portuguese governments also refused to allow the ship to dock, as these costal states claimed that such an oil leakage accident would cause tremendous damage to their local ecological environment. Compared with oil pollution, the impact of an unpredictable pandemic could be greater. Hence, it can be assumed that the coastal and port states were under pressure to deny entry of an infected international cruise ship in the COVID-19 pandemic circumstance.Apart from the coastal and port states, there are other stakeholders who are also accountable for the prevention and control of COVID-19 on international cruise ships, we found that the flag state, the cruise ship company, and the states of the nationalities of onboard passengers and crew members are also legally involved.The flag state of an international cruise ship is the jurisdiction under whose laws the ship is registered or licensed, namely, the nationality of the ship. Many international agreements including various IMO conventions require the flag states to effectively exercise their jurisdiction and control in administrative, technical and social matters over ships flying their flags . Hence, The UNCLOS requires that all ships should have the nationality of the state whose flag they are entitled to fly, and there must be a genuine link between the real owner of the ship and the flag with which the ship flies . HoweverWhile a flag state has the legal authority and responsibility to enforce inspection and safety regulations on international cruise ships that are registered under its flag, the safe operation of ships and the safety of people onboard are primarily the ship operators’ responsibility. Article 1 of the IHR defines an operator as “a natural or legal person in charge of a conveyance or their agent,” which may include ship operators, ship managers and other enterprises, generally referred to as cruise ship companies. Under the current international law framework, there are regulations that specify responsibilities of the states and cruise ship companies with respect to safety and health issues. Article 24 of the IHR, in particular, provides that a state shall take all practicable measures to ensure that ship operators (a) comply with the health measures recommended by WHO and adopted by the state, (b) inform travelers of the health measures recommended by WHO and adopted by the state for application on board, and (c) permanently keep ships free of sources of infection or contamination, including vectors and reservoirs. Corresponding measures to control sources of infection or contamination may be required to apply if evidence is found. When the COVID-19 pandemic is confirmed as a PHEIC, cruise ship companies are obligated to further strengthen their healthcare measures and to cooperate with authorities of coastal and port states as well as their flag state so as to carry out epidemic prevention and control actions effectively, which includes reporting the ship’s actual situation quickly and accurately.As far as the protection of human rights is concerned, the states of nationality of passengers and crew members on international cruise ships are also legally accountable when they are in danger during the COVID-19 pandemic. Both international treaties, such as the International Covenant on Economic, Social and Cultural Rights (ICESCR), and national laws contain relevant provisions that require the state of the nationalities of the people on board to protect its citizens, which entails protecting the right to health, i.e., “the highest attainable standards of physical and mental health” . From thWhile the Diamond Princess cruise ship was at berth in the Yokohama Port, the Japanese authorities decided to quarantine the entire ship, including all passengers and crew members, on the sea instead of at a designated medical institution on shore for inspection and observation. Some of the measures brought about challenges in terms of rationality and legality.According to related international agreements, such as the Convention on the International Regime of Maritimes Ports, the assessing criteria mainly include the necessity, reasonableness, appropriateness, and non-discrimination of applying the measures. Article 28(5) of the IHR provides that, if a suspect or affected ship berths elsewhere than at the port at which the ship was due to berth for reasons beyond the control of the officer in command of the ship, as soon as the competent authority has been informed, it may apply health measures recommended by the WHO or other IHR health measures. Nevertheless, these criteria are generally broad, and, apart from them, there are no other compulsory requirements under existing international legal frameworks. Hence, whether a state’s specific measures are legitimate or not, it should be assessed by the applicable laws of the concerned state.When the Diamond Princess was permitted to berth, Japan as the port state had the discretionary right to take inspection and sanitary measures deemed necessary in accordance with its own domestic laws so as to prevent and control the pandemic, including requiring mandatory quarantine for 14 days. However, the consequence of applying these measures during the quarantine period was that the number of confirmed COVID-19 cases on board continued to rise. There are reasons to doubt that such a situation is directly linked with the quarantine environment of the ship itself as well as certain measures adopted by the Japanese authority. In other words, it appeared that some of Japan’s measures failed to fully consider or even ignored whether the cruise ship itself has the necessary conditions for an effective quarantine. If this can be established, then the rationality and appropriateness of these measures adopted on board would be subject to challenge.Another controversial measure taken by the Japanese government in the Diamond Princess case was that all passengers and crew members on board were prohibited from disembarking, while some held that those healthy people should be allowed to go on shore first. Article 28(2) of the IHR stipulates that ships “shall not be prevented from embarking or disembarking” for public health reasons. However, again, this may be subject to inspection or other measures necessary to prevent the spread of infection or contamination. Article 43(1) further provides that in response to specific public health risks or PHEIC, a country may apply additional health measures in accordance with its relevant national laws if these measures can achieve the same or a greater level of health protection than WHO recommendations. Such measures shall not be more restrictive of international traffic and not more invasive or intrusive to persons than reasonably available alternatives that would achieve the appropriate level of health protection. In addition, from a human rights perspective, IHR Article 3 requires that “the implementation of these Regulations shall be with full respect for the dignity, human rights and fundamental freedoms of persons”. As such, if a country adopts certain public health measures that impose restrictions on free movement or require other interventions at a personal or community level, these measures must consist with human right protection requirements and be balanced with ethical considerations.In the case of the Diamond Princess, because of the poor circulation of fresh air on board, especially in narrow cabins, being quarantined in such a confined space would be more likely to increase cross-infection. Even for healthy people, their immunity would decrease as a consequence of excessive psychological pressure who suffered from the depressive environment, therefore increasing the probability of infection . In otheDuring the COVID-19 pandemic, many international cruise lines were suspended in an effort to prevent the global spread of the new coronavirus disease. Some national governments prohibited foreign cruise ships from entering their ports, making thousands of passengers and seafarers unable to disembark while the ships were at sea. These predicaments highlight the lack of international cooperation and coordination for handling such emergencies. COVID-19 is not the first time that international cruise ships encountered predicaments because of a pandemic. After establishing the public health emergency mechanism under the IHR, the WHO has declared the PHEIC six times. SARS in 2003, the H1N1 influenza in 2013, the Ebola virus disease in 2014, and MERS in 2015 affected the global cruising industry substantially. Similar public health problems are likely to happen again in the future. Therefore, we make the following recommendations for the prevention and control of highly contagious epidemics such as COVID-19 on international cruise ships.First, it must be recognized that in the era of globalization and in the face of a global pandemic, no single state can manage everything, nor can any single international organization solve the problems independently . The preInformation sharing and management is also crucial for the prevention and control of the pandemic. Operating international cruise lines usually involves multiple ports, states, and regions; in the case of epidemic outbreaks, cruise ship companies are expected to work closely with relevant public health authorities to enforce health requirements. It is particularly necessary for them to collect information on the occurrence and development of the epidemic quickly and accurately and to establish a risk assessment mechanism so as to cope with public health emergencies. In this regard, we advise the port states to consider epidemics as an essential indicator in assessing the safety of cruise ships, make files for each visiting ship, and review their emergency response mechanisms regularly.All this international cooperation should be rule-based and under the framework of relevant international organizations including the WHO, the IMO, the ILO, and the International Chamber of Shipping (ICS). Their primary mission is to coordinate diversified regulations and practices of different countries, make suggestions on establishing harmonized or even unified rules, and evaluate whether a country is fulfilling its responsibilities and obligations under relevant legal frameworks. In view of the regulatory controversies that occurred during the COVID-19 pandemic, these international organizations are particularly expected to take a leading role in evaluating key international rules embodied in the IHR, the International Labour Convention, the Convention on Facilitation of International Maritime Traffic and the International Convention for the Safety of Life at Sea. We recommend that these organizations be more actively involved in addressing those new legal issues under the COVID-19 pandemic circumstances by way of improving existing cooperation and surveillance mechanisms of involved parties. In view of strengthening the future global health governance framework, a more effective supervisory mechanism is highly recommended so as to harmonize various national laws on pandemic control with the international health standards.With respect to the specific rules in relation to the prevention and control of COVID-19 on international cruise ships, the future legal frameworks are expected to define more clearly the roles and responsibilities of all stakeholders, especially the coastal states, port authorities, and cruise operators. As a general rule, human rights protection shall be the priority consideration when humanitarian crises occur due to the quarantine of people onboard. Contemporary international law has actually been increasingly highlighting human rights, such as the rights “to just and favourable conditions of work [and] to rest and leisure, including reasonable limitation of working hours and periodic holidays with pay” as stipulated by the UN Human Rights Charter . The genIn line with the human rights principle as well as other UNCLOS rules such as the flag state principle, we recommend further clarification on exercising jurisdiction and distributing responsibilities, so that all involved parties can provide the necessary assistance as much and as conveniently as possible in response to COVID-19 control on international cruise ships.


To define the mechanics and energetics of the myosin motor action in muscles, it is mandatory to know fundamental parameters such as the stiffness and the force of the single myosin motor, and the fraction of motors attached during contraction. These parameters can be defined in situ using sarcomere−level mechanics in single muscle fibers under the assumption that the stiffness of a myosin dimer with both motors attached  is twice that of a single motor (as occurs in the isometric contraction). We use a mechanical/structural model to identify the constraints that underpin the stiffness of the myosin dimer with both motors attached to actin. By comparing the results of the model with the data in the literature, we conclude that the two-fold axial stiffness of the dimers with both motors attached is justified by a stiffness of the myosin motor that is anisotropic and higher along the axis of the myofilaments. A lower azimuthal stiffness of the motor plays an important role in the complex architecture of the sarcomere by allowing the motors to attach to actin filaments at different azimuthal angles relative to the thick filament. These results indicate that An indication of the anisotropy of the motor stiffness arises from the results of the measurements reported by Billington and colleagues . In thatz axis  than along the orthogonal x direction. Since the motors in the experiments reported in [Our interpretation is that the stiffness of the motor is anisotropic, and it is higher along the orted in  are freez, i.e., the axial stiffness of the motor in an attached dimer is about 40% higher than that of a single attached motor. With this estimate for z or less. In this case, the difference in the fraction of attached motors given by mechanical and X-ray measurements cannot be explained only with the higher apparent stiffness of the motors in rigor. We conclude then that the stiffness of the myosin motor is anisotropic, with the lateral stiffness about or less than one order of magnitude the axial stiffness.From the latter relation, with workers  during contraction and in rigor is largely justified.Whatever its exact value, the fact that the azimuthal stiffness is one order of magnitude lower than the axial stiffness explains why the stiffness values of the motor obtained with mechanical measurements and with thermodynamical consideration converge toward a unique value, as discussed in The anisotropy of the stiffness of the cross−bridges has also been suggested by Koubassova and colleagues , applyinSince two consecutive monomers on the same strand of the actin helix are azimuthally rotated by ca 30° relative to each other, the low azimuthal stiffness of the myosin motor can be seen as functional to facilitate the actin attachment of the catalytic domain. The estimated 0.2 pN/nm lateral stiffness of the myosin motor indicates that the root mean square displacement of the tip of the lever arm relative to the hinge with the catalytic domain has a value of about 4.5 nm . With a length of the lever arm of about 9 nm, this means a root mean square of the azimuthal angle between lever arm and catalytic domain of about 26°, which fits well with the azimuthal displacement of consecutive actin monomers along the helical strand, allowing the motor to attach to one or the next without difficulty, whichever better matches its axial position, and it accounts for the second head attachment on the next Z-ward actin monomer in response to a sudden increase in load, as suggested by the mechanical and X-ray diffraction experiments .To conclude, the high stiffness of the myosin motor along the axial direction is able to transmit high force resulting from the structural changes in the motor associated with the working stroke. The much lower stiffness in the azimuthal direction facilitates the motor’s attachment to the actin monomers, which expose their attachment sites for myosin with a large azimuthal range.x and εz, corresponding to the stiffness of the element along the x and z directions, respectively, connected to the z and x axes, which act as the mechanical ground, and together form the tip of the elastic element. The tip of the elastic element, then, is constrained to move in a direction that forms an angle α with the z axis. We have calculated, using the diagram of the forces, the relation between the force F (the stress) applied to the tip of the elastic element and the corresponding elongation (strain)  .To evaluate the effects of the structural constraints of the two motor attachments in rigor on their compound stiffness, we have built a structural model based on the crystallographic coordinates of the acto−myosin complex described in   may move on the surface of a sphere, centered at their Cys707 coordinates with a radius corresponding to the length of the lever arm When the two Lys843 are constrained to be attached to the S2 rod sharing their attachment point, they are also constrained to move along a circle, i.e., at the intersection of the surfaces of the two spheres. Thus, this circle represents the constraint of the distortion of the system constituted by the two actin-attached motors of the same myosin dimer.


Journal of International Neuropsychopharmacology, 18(7):pyu121.Yang, C., Shirayama, Y., Zhang, J-C., Ren, Q., and Hashimoto, K. (2015) Regional differences in brain-derived neurotrophic factor levels and dendritic spine density confer resilience to inescapable stress. A reader noticed that Golgi staining in


This middle-aged patient had undergone surgical placement of a left subclavian to internal carotid artery bypass graft five years ago for treatment of symptomatic, chronic, bilateral carotid occlusions. The patient was neurologically intact after the procedure and until the day of presentation with symptoms of an acute left anterior circulation stroke. Initial workup confirmed acute occlusion of the graft as the cause of the patient’s symptoms. Endovascular recanalization of the bypass graft in the setting of chronic bilateral carotid occlusions was a technical and conceptual challenge. Simultaneous radial and femoral vascular access allowed for direct recanalization of the graft  with intraoperative patency surveillance of the circle of Willis via the posterior circulation. Most of the neurological deficits improved, and the patient was discharged to rehabilitation close to neurologic baseline. Bypass surgeries of the brachiocephalic arteries are less prevalent today than they were in the past. Today, patients can be treated successfully using minimally invasive endovascular devices. However, the presentation of an acute stroke secondary to a bypass graft occlusion can lead to enormous diagnostic and therapeutic difficulties. Our case report offers a technical description of how to recanalize the graft and concomitantly monitor for (and treat) emboli traveling from the distal end of the graft to the intracranial circulation.The patient was a middle-aged, right-handed man, with a history of hyperlipidemia, type 2 diabetes mellitus, hypertension, atrial fibrillation, a prior right cerebellar stroke without sequela, and known bilateral carotid occlusions. The patient was also status post placement of a left subclavian to left internal carotid artery (ICA) bypass graft approximately five years ago for treatment of symptomatic, bilateral carotid occlusions. Of note, the patient was noncompliant with several medications including antiplatelet therapy, anticoagulation, antihypertensives, and insulin. Despite the prior cerebellar stroke and bilateral carotid occlusions, the patient’s modified Rankin score was 0. Upon waking up on the morning of presentation, the patient noticed right upper extremity weakness and pain. A blood pressure check at home showed a systolic blood pressure (SBP) of 190 mmHg. The patient then decided to take an unknown amount of metoprolol. As the blood pressure decreased, dysarthria, aphasia, right facial droop, right-sided neglect, and right upper and lower extremity weakness started to develop. Though the symptoms fluctuated, blood pressure enhancement failed to achieve a return to the patient’s neurologic baseline, and at its worse, the National Institute of Health Stroke Scale (NIHSS) was 17. Initial workup included an unremarkable noncontrast head CT, CT perfusion imaging which showed a 3 cm x 3 cm infarct core in the posterior left temporal lobe and a large ischemic penumbra involving the entire left anterior circulation as well as the right anterior cerebral artery territory Figure . CT angiAnother 4-French Berenstein catheter was navigated into the subclavian artery from the left radial approach due to the more favorable angle for graft catheterization, as per the CT angiogram. The graft itself was radiolucent and not visible on fluoroscopy. The expected take-off of the graft was gently, blindly probed with a 0.035-inch Glidewire . The wire could be advanced into the graft against some minor resistance. The Berenstein catheter could then be navigated into the left cervical ICA across the graft. Intraluminal position was confirmed with a gentle contrast injection.Follow-up angiography revealed an occlusion of the left M1 segment Figure . This waAfter flow through the MCA was restored, a 5-mm Spider embolic protection device  was deployed at the level of the left cervical ICA. Multiple overlapping angioplasties of the graft were then performed using a 5 mm x 20 mm over-the-wire balloon Figure . There wAt that point, it was decided to trap the residual clot in the graft using closed-cell stents. Three overlapping self-expandable Carotid Wallstents  were placed along the entire length of the graft Figure . A balloThe patient’s initial NIHSS was 17 . At the time of discharge, the NIHSS had declined to 3 . MRI was not obtained given the presence of metallic hardware that precluded the patient from undergoing the study, but follow-up noncontrast head CT only showed evolution of a left caudate stroke. The patient was discharged to a rehabilitation facility on dual antiplatelet therapy with aspirin 81 mg (lifelong) and clopidogrel 75 mg (for three months), in addition to warfarin for his atrial fibrillation. A clinical follow-up at three months showed that the patient has fully recovered. A follow-up CT angiogram 10 months after the procedure showed continued patency of the bypass graft Figure .Presentation of severe atherosclerotic disease of the carotid arteries leading to bilateral obstruction can vary from incidental asymptomatic findings to fulminant ischemic strokes, depending on the degree of collateral circulation and the chronicity of the atherosclerotic lesions. Prior to the age of endovascular therapy, bypass techniques of the brachiocephalic arteries were a standard therapeutic approach for management of symptomatic occlusions . As thesIn this case, the combination of multiple vascular risk factors and medication noncompliance led to an atypical anatomical presentation of an acute stroke. The symptomatology exhibited corresponded to hypoperfusion of the left anterior cerebral circulation on someone with known chronic bilateral carotid occlusions who had already undergone a bypass graft from the left subclavian artery to the left internal carotid artery, distal to the native obstruction. This hypoperfusion was initially confirmed by angiographic findings that showed nonopacification of the bypass graft and by perfusion imaging showing a small ischemic core with a large ischemic penumbra that correlated with the patient’s symptoms. Treatment of acute ischemic stroke in the setting of an altered anatomy secondary to the placement of a surgical bypass can be challenging, especially when the graft is the culprit “vessel” of the patient’s symptoms. Recanalization of the occluded vessel via mechanical thrombectomy is the gold standard for treatment of ischemic strokes; however, the specific approach and surgical planning in our case must take into consideration not only the occlusion of the graft but also the prior and permanent occlusions of the native vessels. Endovascular recanalization of an acutely occluded subclavian-carotid graft for the treatment of an acute ischemic stroke has not been described previously. Given that any instrumentation of the thrombotic segment could lead to embolization from the distal end of the occluded graft to the anterior circulation, preprocedural planning was of paramount importance and it prioritized a dual access model that allowed for real-time evaluation of the intracranial circulation via angiograms from the vertebrobasilar system while concomitantly using the left radial access to directly instrument the occluded bypass graft. Initial angiographic imaging via the posterior circulation showed initial patency throughout the circle of Willis through collateral flow from the posterior communicating arteries. As foreseen, initial manipulation of the occluded graft led to an embolus that blocked flow through the MCA. Fortunately, this did not lead to further complications as prompt mechanical thrombectomy was successfully performed. Further embolic events were prevented by deployment of a distal protection device within the cervical ICA. The high clot burden within the graft made direct aspiration therapy insufficient for recanalization. Deployment of overlapping stents not only helped with “trapping” of the remaining clot but also conferred sustained patency of the graft and optimal flow to the anterior circulation.Recanalization of a subclavian to carotid bypass graft via direct aspiration, angioplasty, and endovascular stenting should be considered as a feasible alternative for patients with a clinical presentation of an acute ischemic stroke.


The study focused on the influence of starch modified by octenyl succinic anhydride (OSA) on the rheological and thermal properties of gluten-free dough containing corn and potato starch with the addition of pectin and guar gum as structure-forming substances. The starch blend used in the original dough recipe was partially (5% to 15%) replaced with OSA starch. The rheological properties of dough samples were determined, and the properties of the resulting bread were analyzed. It was found that the dough samples behaved as weak gels, and the values of storage and loss moduli  significantly depended on angular frequency. Various shares of OSA starch in recipes modified dough in different ways, causing changes in its rheological characteristics. The introduction of OSA starch preparations resulted in changes in the bread volume and physical characteristics of the crumb. All the applied preparations caused an increase in bread porosity and the number of pores larger than 5 mm, and there was a parallel decrease in pore density. The presence of OSA starch preparations modified bread texture depending on the amount and type of the applied preparation. The introduction of OSA starches in gluten-free bread formulation caused a significant drop in the enthalpy of retrograded amylopectin decomposition, indicating a beneficial influence of such type of additive on staling retardation in gluten-free bread. In the absence of wheat-related proteins in gluten-free products, starch becomes their principal structure forming component, which has a strong influence on their appearance and texture, and thus consumer acceptance ,2. Corn,Gluten-free products are often based on native starch, which is regarded as a food component, but they could also contain chemically modified starches with a status of approved additives. Their presence influences the water absorption and rheological properties of the dough as well as the texture and staling of bread crumb . ChemicaAmong possible additives applicable in gluten-free bakery products, esters of starch with octenyl succinic acid (OSA) could be especially interesting . This tyThe chemical modifications of starch can be accompanied by the action of various physical treatments. The most important is the pregelatinization combined with drying using roller or spray dryers. The pregelatinization of natural starch or its chemically modified derivatives, e.g., OSA starches, improves water binding. Starch derivatives obtained by this method swell easily in cold water. This may have a positive effect on the structure and properties of the dough and the retention of fermentation gases . AnotherOSA starches are used in baking mostly as ingredients of traditional, wheat-based products. Dapčević-Hadnađev et al.  found thWhile there are a lot of data concerning the use of OSA starches to improve the quality of wheat-based bakery products, less information could be found about the use of these starches in the preparation of gluten-free bakery products, especially those based on native starch. Therefore, the aim of this study was to evaluate the effect of different OSA starch preparations: waxy corn starch sodium octenyl succinate, pregelatinized waxy corn starch sodium octenyl succinate, and starch hydrolyzed and spray-dried waxy corn starch sodium octenyl succinate, on the structure and aging of gluten-free bread. The influence of partial replacement (5% to 15%) of the basic raw material, i.e., corn and potato starch mixture, by OSA starch preparations on the rheological properties of the dough, selected quality parameters of the obtained bread, and its staling rate was evaluated.The structure of the dough based solely on swollen starch granules and non-starch hydrocolloids is much weaker than when gluten-containing flours are used; its consistency is more viscous and less elastic . TherefoThe obtained mechanical spectra show the varying influence of OSA starches on the viscoelastic properties of the dough. An addition of OSA starch I, which was unmodified after esterification, caused an increase in the values of G′ and G″: the larger they were, the higher was the concentration of this starch in the dough (curves not shown). On the other hand, the presence of OSA starch II, which was pregelatinized, affected the values of G′ and G″, and their highest level could be observed for the lowest 5% share of OSA starch. A further increase in OSA starch concentration caused a decrease in moduli; however, even at the highest level of replacement, their values were still higher than those registered for the control sample. The use of OSA starch III, which was hydrolyzed and spray-dried, significantly reduced the values of both moduli: the larger they were, the greater was the share of its preparation in the bread recipe, which may be related to the lower swelling capacity of this preparation. At the identical 15% replacement level c, a signp < 0.05) affect the values of these parameters. The values of the K′ parameter indicating the initial storage modulus G′ increased with the rising share of OSA I starch, although its lowest 5% level had no significant impact here. In the case of OSA II starch, the K′ values were the highest, although they decreased as the starch share in the recipe increased. In turn, in the presence of OSA III starch, the K′ values were reduced, and their drop was the greater the higher was its concentration. The values of parameter n′ indicating the relationship of G′ modulus to angular speed did not change significantly as a result of the addition of OSA I and II starch, with the exception of the highest 15% replacement level. On the other hand, when OSA II starch was introduced into the recipe, the values of n′ decreased significantly, indicating an increase in the dependence of G′ on frequency.The parameters of the power models describing the resulting experimental curves are summarized in Changes in the tangent value of the phase shift angle (tan δ = G″/G′) relative to angular frequency for tested gluten-free dough samples with different OSA starch preparations are shown in Examples of creep and recovery curves, as a dependence of compliance on time, for control and OSA starch supplemented dough are shown in 0) and viscoelastic (J1) compliance values, reflecting the elastic and viscoelastic characteristics of the material, although the effect was significant (p < 0.05) only for higher concentrations of the starch formulation. A significantly greater effect on the reduction of J0 and J1 susceptibility values was observed when the OSA II formulation was used, although the statistical variation within the additive level alone was small (p < 0.05) increased the susceptibility to applied stress, although without a clear trend, as the highest values of J0 and J1 compliance were observed in the sample with 10% of the formulation. In the case of retardation time (p < 0.05) affected the decrease for OSA II and the increase for OSA III in the values of this parameter. The values of zero shear viscosity, which is the viscosity extrapolated to zero shear, changed over time in an opposite way to compliance. A small increase in the value of this parameter was recorded for the OSA II starch preparation, which was significant (p < 0.05) only for the highest concentration. The introduction of OSA II starch resulted in a significantly higher increase in zero shear viscosity values, whereas for OSA III starch, a significant decrease in this parameter was observed.These observations are confirmed by the values of the parameters of the Burgers model used to describe the experimental curves . The preas small . On the ion time  which chp < 0.05) with each other. Such a significant negative linear correlation was observed between the values of instantaneous compliance J0 and the parameters of equations describing sweep frequency test K′ and K”  and viscoelastic compliance J1 and constants K′ and K” . Furthermore, viscoelastic compliance correlated significantly positively with tan δ values (r = 0.65). In contrast, zero shear viscosity values correlated positively with K′ (r = 0.65) and negatively with tan δ (r = −0.94), respectively.Although the methods used to assess the rheological characteristics of dough are based on different foundations, the results obtained using them correlate significantly (p < 0.05) increase observed for the highest concentration of the starch preparation. At the same time, the values of the flow behavior index decreased, indicating a decrease in pseudoplasticity, but the changes were insignificant. On the other hand, the introduction of OSA II starch into the recipe resulted in a significant increase in the consistency coefficient values and a decrease in the flow behavior index values compared to the control sample (p < 0.05) decrease in the consistency coefficient was observed, with a simultaneous increase in the flow behavior index, indicating a decrease in the viscosity of the dough. The viscosity curves of the control dough and samples with OSA starch formulations confirmed that these systems exhibit the characteristics of shear-thinning non-Newtonian liquids (curves not shown), confirming previous observations . The vall sample . In the p < 0.05) correlation between the consistency coefficient K and the parameters K′ and K” (r = 0.92 and r = 0.83) as well as between the consistency index K and the instantaneous compliance J0, viscoelastic compliance J1 (r = −0.81 and r = −0.81), and zero shear viscosity η0 (r = 0.86).The results obtained from the viscosity curves are consistent with the results from the small deformation tests. The changes in apparent viscosity during flow, and hence the values of the consistency index, correlate with the changes in the values of the storage and loss moduli, compliance, and zero shear viscosity. This is confirmed by the values of linear correlation coefficients, which indicate a significant  increase in bread volume in comparison with the control sample, to the greatest extent at the highest share of the modified preparation. The share of this starch in the recipe resulted simultaneously in a significant (p < 0.05) increase in porosity and in the presence of pores > 5 mm in size. At the same time, the presence of this starch reduced the pore density. The other two OSA starch preparations, physically modified after esterification, affected the characteristics of the bread in a differentiated manner, depending on their amount in the dough (p < 0.05) increase in porosity and the number of pores > 5 mm in size, with a simultaneous decrease in pore density in comparison with the control sample. In turn, the introduction of the OSA III starch preparation into the recipe resulted in differential effects on bread volume  effect on reducing crumb hardening compared to the control sample on the first and second days of storage. However, on the third day of storage, all levels of OSA I starch addition reduced crumb hardening relative to the control sample. The introduction of OSA II starch preparation in the recipe at 5% and 10% starch replacement level had no significant effect on crumb hardness, but the highest 15% addition caused a significant increase in crumb hardness on each day of analysis. In contrast, OSA III starch preparation had no significant effect on bread crumb hardness compared to the control sample. A three-factor analysis of variance showed that the type of additive and time significantly (p < 0.05) affected crumb hardness values, while the level of additive alone had no significant effect (p = 0.14). For the combination of factors, only the interaction of time and level had an effect on the values of this parameter. Moreover, a linear negative relationship (r = −0.94) between bread volume and crumb hardness, already known from the literature, was observed. Another parameter determined in the texture evaluation was cohesiveness, which is related to the ability of the particles forming the material to interact with each other. In the case of bread crumb, the decrease of cohesiveness e.g., during storage, causes an increased tendency to crumbling, which negatively affects the consumer acceptance of such a product. The crumb cohesiveness results of the tested samples are shown in p = 0.025) importance here. Since chewiness and hardness values are correlated (r = 0.99); the effect of OSA starch preparations on chewiness (p < 0.05) affected crumb chewiness values, while additive level alone had no significant effect (p = 0.60). For combinations of factors, only the interaction of time and type of starch affected the values of this parameter.The textural properties of bread to a large extent determine its acceptance by consumers. During the storage of bread, especially gluten-free starch-based bread, a number of structural changes occur that result in reduced product acceptability. These changes are mainly associated with water migration from crumb to crust and crumb hardening resulting, among others, from starch retrogradation. Various types of additives or ingredients that control water retention and/or reduce starch retrogradation are used to limit these adverse phenomena ,5,23. Onhewiness c was simAn important factor having a key influence on the correct and acceptable for consumers texture parameters is the ability of dough to retain fermentation gases causing an increase in crumb volume and porosity, which also results in a decrease in its hardness. The addition of OSA starch preparations may have a beneficial effect on decreasing the crumb hardness and increasing the crumb softness. Dapčević-Hadnađev et al.  found thp < 0.001) influenced the changes in the enthalpy value of the transition related to the decomposition of recrystallized amylopectin. However, the level of the additive alone had no significant effect in this case (p = 0.09). In addition, combinations of individual factors had a significant (p < 0.05) effect on enthalpy values. In general, enthalpy values increased with increasing storage time regardless of sample type , potato starch , OSA I starch (C*EmTex 06369-waxy corn ester-starch sodium octenyl succinate), OSA II starch (C*EmTex 12688-pregelatinized waxy corn ester-starch sodium octenyl succinate), OSA III starch (C*Emcap 12635-hydrolyzed and spray-dried waxy corn ester-starch sodium octenyl succinate) , guar gum , high methylated apple pectin ), freeze-dried yeast , rapeseed oil Kujawski , sugar, salt , and water.The basic control bread recipe was based on our earlier research . The douThe rheological properties of the dough were characterized at 25 ± 0.5 °C using the MARS II oscillating rheometer  equipped with a parallel plate system . Samples of the dough (without yeast) were placed in the measuring system of the rheometer, protected against evaporation with paraffin oil, and left for 5 min to relax stresses and stabilize the temperature.G′—storage modulus (Pa), G″—loss modulus (Pa), ω—angular frequency (rad/s), K′, K”, n′, and n″—constants.The mechanical spectral was determined in the linear viscosity range at a constant deformation amplitude of 0.1% in the angular frequency range of 1–100 rad/s. Experimental data were described by power equations:0 = 2 Pa during 150 s. The recovery phase continued for 300 s. Experimental data were described using the Burgers model:J—compliance (Pa−1), J0—instantaneous compliance (Pa−1), J1—viscoelastic compliance (Pa−1), η0—zero shear viscosity (Pa∙s), retλ—retardation time (s), and t1—the time after which the stress was removed (s).Creep and recovery tests were performed at constant strain in creep phase τ−1. Experimental data were described by the power equation:apη—apparent viscosity (Pa·s), K—consistency coefficient (Pa·sn), −1), and n—flow behavior index.The viscosity curves were determined at the controlled shear rate in the range 1–10 sAfter weighing, all dough ingredients were mixed for 8 min . The resulting dough was fermented for 15 min  and stirred again for one minute. Then, 250 g of dough was weighed into greased metal forms. The final fermentation was carried out within 20 min under conditions as stated earlier. The bread was baked within 30 min at 230 °C . Once removed from the oven, the bread was cooled for two hours at ambient temperature (around 21 °C) and used for further analysis. Each dough was made in duplicate based on individual recipes; five loaves were baked in each repetition. In order to assess changes in texture parameters during storage, some samples were packed in polyethylene bags and stored at 22 ± 2 °C.The volume of bread was measured using the Volscan 600 . Image analysis was performed for 1 cm thick samples taken from the inner parts of each loaf that were scanned with the Plustek S-12 flatbed scanner. Recorded images were analyzed using ImageJ v. 1.44p. Porosity, pore density, and average pore size were assessed.Texture profile analysis (TPA) of bread crumb was performed using the TA-XT2plus texture analyzer  at a compression rate of 5 mm/s. A cylindrical sample of bread crumb with a diameter 1 cm and height 2 cm was compressed to achieve 50% deformation with the P/35 aluminum cylindrical probe in two cycles. The resulting hardness, cohesiveness, and chewiness values were used as indicators for the changes in crumb texture during storage. Calculations were performed using Texture Exponent . Analyses were carried out 2, 24, and 48 h after baking.The thermal characteristics of the bread crumb were obtained using the DSC 204F1 Phoenix differential scanning calorimeter . On each day of analysis, after 2, 24, and 48 h after baking, crumb samples weighing 15 mg of were taken from the center of the loaf, hermetically sealed in aluminum pans, and heated in a calorimeter from 20 to 100 °C at a rate of 10 °C/min. The empty aluminum pan was used as a standard. Thermal transition temperature and enthalpy were calculated using the Proteus Analysis software . Enthalpy values were expressed in J/g of d.b.t-test. Calculations were performed using Statistica 12.0 .In order to assess the significance of the differences between the averages, the data were subjected to a single- and two-factor analysis of variance, and the significance of the differences between the averages was determined by the Duncan’s test at a significance level of 0.05. A three-factor ANOVA was used to determine the effect of the type of OSA starch, the level of its addition, and the storage time on texture parameters and enthalpy of the recrystallized amylopectin decomposition. The relationship between the resulting parameters was assessed using Pearson’s correlation coefficient values, the significance of which was checked using the Student’s On the basis of the results, it was found that the analyzed dough samples behaved as weak gels and the values of moduli G′ and G″ significantly depended on the angular frequency. The introduction of OSA starch preparations modified the dough structure in a different way, influencing changes in its rheological characteristics and susceptibility to stress. The key factor here seems to be the ability of these preparations to absorb water. The OSA preparation subjected only to esterification strengthened the structure of the dough, influencing the decrease of its compliance to stress. This increases the possibility of the dough to retain fermentation gases, having a positive effect on the increase in bread volume. The preparation of pregelatinized OSA starch, on account of its high water absorption capacity, caused significant strengthening of the structure and a rapid decrease in susceptibility to stress. However, a too high share of pregelatinized OSA starch, through too high strengthening of the dough structure and limited ability to retain fermentation gases, caused a decrease in the volume of loaves and an increase in crumb hardness. On the other hand, hydrolyzed and spray-dried OSA starch significantly increased the dough susceptibility to stress, weakening its structure. This resulted in a decrease of bread volume at a lower proportion of such preparation. On the last day of the study, a significant decrease in enthalpy of retrograded amylopectin decomposition values was observed in all breads containing the tested OSA starch preparations, regardless of their amount. This indicates the possibility of reducing the retrogradation of amylopectin responsible for crumb hardening during bread storage. In terms of the quality of the bread related to the increase in the volume of the loaves and the delay in hardening of the crumb during storage compared to the control sample, the preparation of waxy corn starch sodium octenyl succinate showed the best effect.


In this study, we evaluate the value of novel suture material based on monofilamentous-extruded polyfluoroethylene (PTFE) compared to polypropylene (PPL) and Fiberwire (FW).60 flexor tendons were harvested from fresh cadaveric upper extremities. 4–0 sutures strands were used in the PPL, FW and PTFE group. Knotting properties and mechanical characteristics of the suture materials were evaluated. A 4-strand locked cruciate (Adelaide) or a 6-strand (M-Tang) suture technique was applied as core sutures for a tendon repair. Two-way ANOVA tests were performed with the Bonferroni correction.Stable knotting was achieved with 5 throws with the PPL material, 7 throws for FW and 9 throws for PTFE. In the PPL group, linear tensile strength was 45.92 ± 12.53 N, in the FW group 80.11 ± 18.34 N and in the PTFE group 76.16 ± 29.10 N. FW and PTFE are significantly stronger than PPL but show no significant difference among each other. Similar results were obtained in the subgroup comparisons for different repair techniques. The Adelaide and the M-Tang knotting technique showed no significant difference.Fiberwire showed superior handling and knotting properties in comparison to PTFE. However, PTFE allows easier approximation of the stumps. In both, M-Tang and Adelaide repairs, PTFE was equal to FW in terms of repair strength. Both PTFE and FW provide for a robust tendon repair so that early active motion regimens for rehabilitation can be applied. There is a plethora of evidence stating that early active motion promotes tendon healing and diminishes adhesions after flexor tendon repair , 2. StreFiberwire®  is a polyblend strand. It is composed of a multi-strand, long-chain ultra-high molecular weight polyethylene (UHMWPE) core with a braided jacket of polyester and UHMWPE. Seramon® is a polytetrafluoroethylene (PTFE) monofilamentous strand produced with a novel production process rendering it substantially stronger than other known PTFE materials (eg. Gore-Tex®). Related substances like Gore-Tex® (expanded polytetrafluoroethylene) or Teflon are widely used in cardiovascular and plastic surgery. There is little foreign body reaction in animal models using the material which stands for an adequate biocompatibility –8.Newer 4–6-strand repairs can achieve an initial tensile strength of up to 100 N (N) . IsolateIn non- or minimally displaced bony avulsion of the Flexor digitorum profundus tendon, conservative treatment also can be an option and has a good outcome .Furthermore, if primary reconstruction of the flexor tendon is not possible or led to an insufficient outcome, secondary reconstruction methods can be performed . In addiFor the purpose of this study, 60 flexor tendons were harvested from non-fixated cadaveric upper extremities. The donor extremities were provided by the Institute of Anatomy, University of Erlangen. The use of the human material was in full compliance with the university policy for use of cadavers and recognizable body parts. For the study, 9 flexor tendons of the fingers and the thumb were utilized as well as the flexor carpi radialis tendon. Six upper extremities from four different donors were used, two female and two male ones. The tendons were obtained from geriatric cadaveric donors with an age range between 65 and 80 years old. Prior to refrigerating, the cadavers were exsanguinated. No deep freezing was performed prior to harvesting of the tendons. The full length of the tendinous part of the units was harvested, to provide for better anchoring onto the measuring device. The tendons were then transected at the middle point by means of a No 11 blade.n = 10. A core suture purchase length of 12 mm was controlled for all groups of tendon repair. The size of locking and grasping anchors was 2 mm. No additional epitendinous suture was performed.In literature, many different suture techniques for flexor tendon repair are published and evaluated , 20. In For all measurements of linear strength, a universal testing device TIRAtest 28025a,  was used. Testing velocity was set to 300 mm/min. For the measurements, a 1kN modular component was used. The suture material and the repaired tendon were mounted and clamped on both ends. The contact side of each plate had multiple serrations to improve grip on the tendon during testing. The loading continued until failure and the maximum tensile force was noted as ultimate tensile strength.n = 10) specimens were mounted and measured for linear tensile strength. Subsequently, the suture was divided and knotted with an ascending number of opposing throws. The point was verified when the strand was prone to break at the knot rather than slip (for every group n = 3). After finding the minimum of knots needed to prevent slippage, we tested all three 4–0 strands (n = 30) for linear strength at the knotting point.Three different strands were used for the tendon repairs: Polypropylene (PPL) , Fiberwire (FW)  and polytetrafluoroethylene (PTFE), . In literature, 3–0 or 4–0 strands are recommended . We usedn = 10 for each group, 6 groups altogether, with an estimated effect size of 0.5 and α-value of 0.05 resulted in a power of 0.824. We assumed an estimated delta of 23.5 N between PTFE and PPL due to our previous study [Two-way ANOVA was used for comparison between the groups. Power analysis for a sample size of p < 0.001). In a preliminary experiment, the number of throws required to achieve a stable knot without the risk of slippage was determined. In PPL, the required number of throws was 5, in FW, it was 7 and in PTFE 9. Knotted PPL displayed a linear strength of 11.71 ± 0.306 N. Knotted FW broke at 23.95 ± 3.920 N and PTFE had a linear tensile strength of 21.57 ± 0.773. The results are summarized in Fig. 4–0 PPL strands demonstrated linear tensile strength of 16.37 N ± 0.21. FW demonstrated the highest linear traction strength of 72.16 N ± 4.34. PTFE demonstrated a linear tensile strength of 22.22 N ± 0.69. All comparisons of intergroup linear strength were highly significant (Tensile strength of PPL 4–0 suture with the Adelaide repair was 39.69 N (30.88–47.74 ± 5.57). Tensile strength of PPL 4–0 suture with the M-Tang repair was 52.14 N (33.44–76.42 ± 14.21).Tensile strength of Fiberwire 4–0 suture with the Adelaide repair was 70.96 N (51.51–111.47 ± 21.18). Tensile strength of Fiberwire 4–0 suture with the M-Tang repair was 89.25 N (76.87–100.61 ± 8.68).Tensile strength of PTFE 4–0 suture with the Adelaide repair was 72.79 N (14.37–100.29 ± 27.91). Tensile strength of PTFE 4–0 suture with the M-Tang repair was 80.97 N (42.810– 137.75 ± 30.55). There was no significant difference between Adelaide and M-Tang repair within any of the material groups. However, both FW and PTFE proved to be significantly stronger than PPL in both settings. No significant difference could be detected among FW and PTFE. A summary of the results is demonstrated in Table Repairs with PTFE displayed a peak tensile strength comparable to FW. Both repairs were significantly stronger than those with PPL Fig. Both, knot breakage and pullout occurred. Repair failure due to pullout was 10% in the polypropylene group, 30% in the PTFE group and 50% in the Fiberwire group.In a previous study , we testTesting of the solitary strands with or without prior knotting provided important insights. With constant linear tensile strength and without knotting, FW proved to be significantly stronger than the two other materials. However, after knotting this difference vanishes, indicating that FW is prone to mechanical distortion. Knotting to some extend inflicts distortion of a strand and therefore the knot itself presents a breaking point. This effect seems to be profound in the FW material, nevertheless, even after knotting FW retains excellent tear strength properties. On the contrary, there was no loss of tensile strength by knotting for the PTFE strand. A degree of plastic distortion is necessary for a knot to hold, so it is no surprise that 9 or more throws of a knot are needed for PTFE to hold. In this experimental setting, we expected tensile force measurements of more than 100 N. Knotting with 9 throws was necessary for this experimental setting. We expect that a flexor tendon repair with 5–6 knots will be adequate in the clinical setting. However, even 5–6 knots are quite bulky.We first faced difficulty handling the PTFE material due to very low surface friction and a “slippery” feeling. Strict training was required to handle the comparatively slick material. On the other hand, approximating the tendon stumps and tightening of the repair went smoother, affording less tissue trauma. The material was very pliable in great contrast to the ominously rigid PPL but also in comparison to FW. With the M-Tang technique combined with FW, there was some difficulty adjusting the tension of the last 2 strands to the tension of the initial 4 strands. Finally, the knot of the PTFE strand ended up being very bulky in comparison to the other materials, however, with the Adelaide technique, the knot can be buried between the stumps.The results indicate that when FW or PTFE strands are used, the initial repair strength is adequate for early active motion rehabilitation. As previously shown, active finger flexion exposes uninjured flexor tendons to forces of up to 20 N , 24. ConThe PTFE material (Seramon®) in our study displayed an array of positive properties . It is dIt has to be underlined that also the flexor carpi radialis tendon was used which could lead to discrepancies and adds an additional variable. Also, the flexor tendons of the thumb were used, which can additionally cause a discrepancy. Yet, the different tendons were distributed evenly in the groups. However, regarding the high number of trials, significant results and, respectively, low standard deviation, there seem to be no major differences between the used types of flexor tendons.A certain limitation of the study has to be mentioned as well: this study did not assess the capacity of gap resistance of flexor tendon repair, such as gap formation force and stiffness of tendon repair.Mechanically is PTFE equal to FW, providing for a robust flexor repair capable of supporting early active motion. However extremely low surface friction properties render multiple bulky knotting necessary. Adaptation of surgical technique would be required. However, approximating the tendon stumps and tightening of the tendon repair went smooth which should cause less tissue trauma.In summary, we hold PTFE strands suitable for a clinical trial on flexor tendon repair.


We describe a technique for revision anterior cruciate ligament (ACL) surgery using a 15-cm strip of the iliotibial band as a graft and the gracilis tendon if available. An internal brace is added to augment the graft. The graft is passed through the femur by drilling an outside-in tunnel from the isometric point F9 of Krackow toward the ACL’s footprint and is then double fixed at the tibia using an interference screw and a cortical button. This technique makes it possible to perform simultaneous ACL reconstruction and lateral tenodesis with a continuous, rigid, good-diameter graft that is pedicled to the Gerdy tubercle. Good rotational control is achieved, and all the factors that contribute to ligamentization are present. Overview of outside-in anterior cruciate ligament revision technique with iliotibial band. First, we describe the main anatomic landmarks; then, we describe the technique used to harvest the graft, to create the tunnel, and to fix the graft. The video emphasizes tips and tricks useful for this surgical procedure such as the intermuscular septum sectioning technique, which enables posterior fascia advancement. The retear rate after anterior cruciate ligament (ACL) reconstruction is substantial, ranging from 4.4%The fascia lata or iliotibial band (ITB) is biomechanically suitable as an ACL graft. According to Chan et al.,Our purpose is to describe a technique for arthroscopic revision after an ACL retear using an ITB autograft, augmented by a gracilis autograft if present and an internal brace.The causes of the retear must be identified among the following: trauma 32%), technical error , biological (7%), or a combination of the aforementioned factors (37%).%, techniThe patient is placed supine on the operating table in the standard arthroscopy position . A tournA 10-cm skin incision is made 2 cm proximal to the Gerdy tubercle (GT). The posterior ridge from the GT is incised with a No. 23 blade and extended proximally 5 to 6 cm; a second incision is made 1 cm anterior and parallel to the previous incision, so the graft is 1 cm wide at its distal end. The proximal portion of the ITB is exposed with 2 retractors, and the posterior incision is extended proximally with the same blade to obtain a total graft length of approximately 15 cm. The anterior incision is then extended to obtain a 3-cm-wide graft at its proximal end . The disThe surgeon must confirm that the gracilis was not used during the first ACL reconstruction. A standard vertical 2-cm incision is made medially to the anterior tibial tuberosity. The gracilis tendon is harvested with an open tendon stripper and then cleaned and cut close to its tibial insertion. Hyperflexion provides better access to the most proximal vincula. Tubulization of the ITB is performed around the gracilis tendon in this scenario.The isometric point F9 of KrackowThe tourniquet is deflated, and meticulous hemostasis is ensured, especially bleeding from the vessels deep to the ITB, just behind the lateral condyle. We recommend using the intermuscular septum sectioning technique, which enables posterior fascia advancement.The knee is not immobilized with a brace, except in cases with radial or complete meniscal root tears. All patients undergo surgery on an outpatient basis. A routine ACL rehabilitation program is started on the first postoperative day, entailing full weight bearing and progressive exercises to regain range of motion and quadriceps function. A gradual return to sports is generally allowed starting at 4 months for nonpivoting sports, 6 months for noncontact pivoting sports, and 8 to 9 months for contact pivoting sports, after isokinetic tests and a functional evaluation.The described ACL revision technique, which uses the ITB and gracilis as grafts and is augmented by an internal brace, has several advantages: (1) ACL reconstruction and lateral tenodesis can be performed simultaneously. Lateral tenodesis is an effective supplement for added rotational control in the setting of ACL revision.The gracilis is not essential to this ACL revision technique; however, if it is still intact, harvesting it adds to the graft’s diameter or length when the ITB is too short or too thin.One of the challenges of ACL revision is having to drill a new femoral tunnel. Most primary ACL reconstructions use an inside-out technique . Attaching the graft is more difficult when the tunnel drilled for the previous reconstruction is large or has widened, which may require a 2-stage revision and bone grafting.Our technique uses an internal brace (FiberTape) to increase the graft’s rigidity and protect it until the end of the ligamentization process. One study has shown that an internal brace increases the biomechanical performance of intra-articular ligament reconstructions and does not affect bone tunnel healing.Our ACL revision technique combining ITB and gracilis autografts augmented by an internal brace is simple and easy to perform. We have performed more than 50 ACL revisions using the ITB and gracilis in the past 2 years and have not seen any retears. A randomized controlled trial comparing our technique and a technique combining a bone–patellar tendon–bone graft and modified Lemaire lateral tenodesis is underway. The early results are encouraging .


Non-anastomotic thoracic aortic graft rupture is extremely rare and difficult to diagnose. Non-obstructive general angioscopy can help monitor the aortic intima and detect the locations of abnormal findings, while aortic angioscopy can detect vulnerable plaques in the aorta, which are difficult to visualize using conventional diagnostic methods. Herein, we report the case of a patient with non-anastomotic thoracic aortic graft rupture diagnosed using non-obstructive aortic angioscopy.An 85-year-old man who had undergone total arch replacement 5 years prior complained of chest pain. Emergent contrast-enhanced computed tomography (CT) revealed an intra-mediastinal hematoma around the vascular graft of the ascending aorta and angiography revealed pooling of contrast medium on the dorsal side of the vascular graft. We suspected extravasation of the thoracic vascular graft. Aortic angioscopic examination revealed a red vascular graft defect that matched extravasation at the contralateral level of the prosthetic left common carotid artery branch. Subsequently, non-anastomotic thoracic aortic graft rupture was diagnosed. The patient underwent a two-debranching thoracic endovascular aortic repair (Zone 0) with a right subclavian artery-left common carotid artery-left subclavian artery bypass. Postoperative angiography revealed disappearance of the extravasation from the graft rupture site, patent grafted vessels with flow, and no endoleak. Follow-up CT at 6 months postoperatively showed no extravasation.To our knowledge, this is the first report of non-anastomotic thoracic aortic graft rupture detected using non-obstructive aortic angioscopy. Aortic angioscopy can help establish a definitive diagnosis in patients with aortic graft rupture.The online version contains supplementary material available at 10.1186/s40792-022-01394-w. Disruption of prosthetic vascular grafts can be divided into two major categories: anastomotic and non-anastomotic failures. To date, most reports have focused on anastomotic failures associated with infections . There aAlthough conventional imaging modalities, such as computed tomography (CT), magnetic resonance imaging (MRI), and transesophageal echocardiography (TEE) have been used to diagnose aortic diseases, the ability to detect millimeter-sized plaques is limited because of the relatively poor spatial resolution , 4. MoreHerein, we report the case of a patient with non-anastomotic rupture of a prosthetic vascular graft that was diagnosed using non-obstructive aortic angioscopy which is known to help monitor the aortic intima and locations of abnormal findings.An 85-year-old man with a history of total aortic arch replacement performed using a 26-mm, four-branched Triplex graft  for an aortic arch aneurysm 5 years previously, was admitted to the emergency department with chest pain.Laboratory data exhibited anemia (Hb 9.4 mg/dL), elevated inflammatory markers , near normal renal function, elevated bilirubin level , and negative blood culture results. TTE confirmed an ejection fraction of 60% and mild aortic valve regurgitation without any tamponade sign.Emergent contrast-enhanced CT revealed an intra-mediastinal hematoma around the vascular graft of the ascending aorta and extravasation on the dorsal side of the center of the vascular graft Fig. A, B.Fig.Emergent angiography, which was performed under general anesthesia in a hybrid operating room, revealed pooling of contrast medium on the dorsal side of the vascular graft. However, the source of the leak was unclear. Aortic angioscopic examination of the graft was performed using a non-obstructive angioscopy system . This revealed a red vascular graft defect  were revascularized via right SCA-left CCA-left SCA bypass using an 8-mm T-shaped ring-enforced polytetrafluoroethylene graft. A cTAG stent-graft  was deployed just distal to the first graft branch of the brachiocephalic artery via a femoral approach.Finally, embolization at the left SCA was performed using the Vascular Plug 12 mm), and the proximal left CCA of the bypass anastomosis was closed with a Hem-o-lok XL . A final angiography revealed the disappearance of the extravasation from the graft rupture site, patent flow to the grafted vessels, and no endoleak (Fig.  mm, and Rupture after thoracic aortic surgery is usually caused by anastomotic failure. The literature reports a frequency of 1–12%, and the diagnosis is usually made 8–10 years after the original surgery . As a diIn this case report, blood tests at the time of admission showed elevated inflammatory markers but negative blood culture results. Therefore, infection was ruled out as a cause for the graft rupture.In addition, the rupture site of the vascular prosthetic graft was on the dorsal side of the prosthetic graft, and aortic wrapping was not performed in the previous surgery. Therefore, it is unlikely that the graft rupture was caused by physical damage, and the cause of graft rupture was unknown.Furthermore, a rupture site is sometimes difficult to detect despite using CT or angiography especially in the emergent case. When the rupture site is a proximal anastomosis, open surgery is the only treatment option. However, it is possible to perform endovascular treatment for a rupture of the graft itself or the distal anastomosis site. Therefore, detection of the rupture site was crucial in our case, because the patient had a high risk of open repair due to age and frailty.Graft rupture was suspected on imaging. However, since graft rupture is extremely rare, we had to make a definitive diagnosis. Therefore, we prepared to treat the patient as soon as the rupture site was confirmed and performed angioscopy in the hybrid operating room. Angioscopy helped determine the rupture site and we immediately started two-debranching thoracic endovascular aortic repair.Non-obstructive general angioscopy is a novel method that may have important implications for the diagnosis and management of vulnerable atherosclerotic plaque , 11. FurWe reported the efficacy of non-obstructive aortic angioscopy for definitive diagnosis in a patient with graft rupture.Additional file 1: Video S1.


Journal of Orthodontics.To survey the opinion of British Orthodontic Society members on the Data collection involved an anonymous cross-sectional online SurveyMonkey™ questionnaire.Journal. Data were analysed for the membership as a whole using simple descriptive statistics.An email invitation to complete the survey was sent to the 1842 members of the British Orthodontic Society on 9 June 2020 with a follow-up reminder on 15 July 2020. The invitation contained a brief description and online link to the questionnaire, which was active between 9 June and 9 August 2020. The 15-item questionnaire covered frequency of reading, preferred format, likes and dislikes, and what changes might improve the Journal  was through the distributed print copy. Overall, 63.6% (n=197) rated the Journal as excellent and 35.2% (n = 109) as satisfactory, with only 1.3% (n = 4) responding that it was poor. The scientific and clinical articles were the most popular aspect of the Journal and 90.3% (n = 280) of respondents felt the Journal content was relevant to their current clinical practice. Respondents were also given the opportunity to make additional free-text comments; and themes that emerged included a wish for more clinical content, more online interaction with authors through webinars and continued professional development.In total, 310 individuals completed the questionnaire, representing a response rate of 17% with 74.2% (n = 230) reporting reading at least one article per issue. The most popular way of reading the Journal of Orthodontics is perceived as being relevant to current clinical practice by members of the British Orthodontic Society and has high-level satisfaction. There is a desire for more online interaction with the membership as part of its role within the society. However, the overall response rate was low and therefore a high risk of potential bias associated with this survey.The  Journal of Orthodontics is an international peer-reviewed academic journal with a global circulation, publishing high-quality, clinically orientated and relevant original research that underpins evidence-based orthodontic care  Consultant Orthodontist Group  Training Grades Group , Practitioner Group , University Teachers Group  and Community Group . All members of the British Orthodontic Society receive a hard copy of the Journal, which can also be accessed online from the British Orthodontic Society website by signing in as a member. There is also continued professional development offered in relation to articles within each issue and mediated through the society website. A key responsibility for the editorial board is to produce the four print editions per year, while maintaining academic quality and standards and ensuring that ongoing content and features are relevant and continue to appeal to the readership. For this reason, it is important to engage with the readership and canvass opinion and feedback on how the Journal is perceived and how it might change moving into the future.The  Society . It bega in 2000 . As the  in 2000 . The JouJournal of Orthodontics in order to help establish current subscribers’ perceptions of and opinions of the Journal in its current form.The aim of the present study was to survey members of the British Orthodontic Society in relation to the content and organisation of the Appendix 1). Approval was requested from the British Orthodontic Society Clinical Governance Committee to allow distribution of the survey among its members and this was granted on 4 May 2020. The 15-item questionnaire was developed through consultation with the editorial board of the Journal of Orthodontics and was based upon a number of perceived key features of the Journal for the readership. An email invitation to complete the survey was sent to all 1842 members of the British Orthodontic Society on 9 June 2020 with a follow-up reminder email invitation on 15 July 2020. The criteria to receive an invitation were: (1) member of the British Orthodontic Society and therefore in receipt of the Journal of Orthodontics quarterly; and (2) in possession of a valid email address. The email invitation contained a brief description of the survey’s purpose and an online link to the questionnaire, which was active between 9 June 2020 and 9 August 2020. The questionnaire was created using the online survey provider SurveyMonkey™. The secretary of the British Orthodontic Society distributed the invitation and reminder emails including the survey link to the membership, with all questionnaire responses processed anonymously within SurveyMonkey™. Hence, the confidentiality of all responders was maintained throughout all stages of the study.Data collection involved the use of an anonymous, descriptive, cross-sectional, online, questionnaire-based survey  identified themselves as specialist practitioners, with 33% (n = 102) identifying as consultant orthodontists and 11% (n = 34) as members of the training grades. In addition, 13% (n = 40) classified themselves as ‘other’ .Journal content, the majority of responders  stated that they usually read at least one article in each edition that they received, while 18.7% (n = 58) and 0.6% (n = 2) only read articles in a couple or only a single edition per year, respectively. Among the remainder, 4.2% (n = 13) only look at the table of contents and 2.3% never even open it! In terms of the number of editions that are produced per year, the majority of responders  would like to see an increase, while 42.9% (n = 133) were happy with the current production of one issue every three months.In terms of general interest in Journal using both formats. A small number of respondents  stated that they used neither method to read the Journal. When asked if they would prefer to receive a digital copy of the Journal each quarter, the majority of respondents  said no, they would not.There are now multiple methods available to read academic journals but the vast majority of respondents  still read a hard copy; however, 5.8% (n = 18) now read the digital copy, while 15.5% (n = 48) read the Journal was generally rated positively by respondents, with 63.6% (n = 197) stating that it was excellent, 35.2% (n = 109) satisfactory and only 1.2% (n = 4) suggesting that it was poor. There were also  did suggest that there were other things they did not like, and a selection of these responses is shown in The disliked  and b. IJournal has produced a number of supplements in addition to the normal four issues over the last few years, with subject areas including medical problems and orthodontics, lingual appliances, temporary anchorage devices and contemporary issues in orthodontics. When the readership was asked if it would like to see more supplements, there was a fairly even split between those that would  and those that would not . When asked if they had a favourite supplement from the last few years, most respondents did not . When the 60 comments made by responders in relation to this question were analysed, the medical problems in orthodontics and lingual appliances supplements were the most popular supplements.The Journal is the perceived relevance that it has in terms of clinical practice. The vast majority of respondents  felt that it was relevant to their clinical practice.A further important aspect of the Journal also carries a limited number of advertisements, which are administered by the British Orthodontic Society, and just over half of respondents  felt that these were useful. However, 26.1% (n = 81) stated that they did not like to see advertisements and 10.3% (n = 32) felt that the Journal should not carry advertisements.The Journal of Orthodontics  answering that, yes, they did and 31.3% (n = 97) saying that they did not. If they did receive other orthodontic journals, they were further asked to state what they were and a total of 175 individuals did this . A numbeThe final question related to general feedback and all 310 respondents made at least one comment. A selection of these comments is reproduced in Journal of Orthodontics, which is the representative academic journal of their society. This is the first time that the readership of the Journal has been asked directly to give their opinion on content and potential future direction relating to this publication. In broad terms, the level of satisfaction with the Journal was good among the readership, which suggests that the Journal is fulfilling its essential remit for the British Orthodontic Society. This is consistent with previous readership surveys of both dental and medical journals  between 1999 and 2008, around half the articles published in the Journal of Orthodontics reported treatment of human subjects with at least 20% of each edition containing case reports (Angle Orthodontist and European Journal of Orthodontics, respectively (Journal of Orthodontics is ‘too academic’ may be unfounded. Despite this, it appears that not all clinical articles and their content appeal to everyone. This is highlighted by free-text comments such as ‘More practice-based clinical pearls’ and ‘Slightly more clinically relevant articles focusing on all treatment modalities – aligners/ceramics, etc., to broaden our horizons – not just NHS-funded treatments’. To address this type of need, some journals have clinical case letter sections, which aim to inform readers of new or alternative clinical techniques or interesting clinical situations (One theme was the feeling that the inicians . Indeed,inicians . This do reports . In addiectively . Based otuations .Journal, perhaps through webinars with authors and by expanding the continued professional development associated with published articles. There was a feeling from some that many papers published by the Journal are often from the same authors and that subject areas can be repetitive. When considering how the Journal is placed in relation to other international orthodontic journals there was divided opinion, with some respondents suggesting that it needs to develop a more international focus rather than being a ‘society’ journal. Among other orthodontic journals that are published, the American Journal of Orthodontics and Dentofacial Orthopedics was held in high overall regard, while the European Journal of Orthodontics was also popular, albeit with the caveat that it tends to publish a lot of biological articles. Interestingly, Orthodontic Update received a lot of positive comments, the clinical-focussed content being popular with readers. A number of respondents raised the issue of the Journal of Orthodontics lacking an impact factor, which they perceived as being a barrier to its further development. They suggested that many United Kingdom academic orthodontists publish their work in other orthodontic journals for this reason. There may be some truth in this statement, and certainly the lack of impact can be a barrier to receiving the best submissions, although it is questionable whether many universities would use articles published in any of the orthodontic specialty journals for a research assessment exercise. It should also be remembered that a journal impact factor is not the only metric of academic rigour and over the years, through the efforts of previous editors, such as Kevin O’Brien and Philip Benson, the Journal of Orthodontics has been proactive in encouraging high reporting standards for its articles (Journal of Orthodontics.Another suggestion was the incorporation of more reader interaction with the articles . Moreovearticles . Impact It was decided to maximise anonymity in association with the survey to encourage honest and wide-ranging responses, which meant only limited demographic data were available. There are sources of bias associated with this survey, not least the relatively low response rate from the membership. Given the previous trend of low response rates to British Orthodontic Society member-surveys on subjects such as orthodontic treatment planning and training experiences , strategJournal of Orthodontics. The Journal is perceived as being relevant to current clinical practice and has high levels of satisfaction. However, there was some desire for more online interaction between the membership and Journal as part of its role within the society. These conclusions should also be considered within the context of a low response rate and the existence of potential bias.This survey has provided some insight into the opinion of members of the British Orthodontic Society who receive the Click here for additional data file.Journal of Orthodontics: A cross-sectional survey of British Orthodontic Society members by Rosalind Jennings, Jadbinder Seehra and Martyn T Cobourne in Journal of OrthodonticsSupplemental material, sj-docx-1-joo-10.1177_1465312520988549 for The