open surgery for fracture stabilization is often inappropriate in this population due to a poor risk - benefit profile , particularly if life expectancy is short .
percutaneous vertebroplasty and kyphoplasty are appealing adjunctive procedures in patients with malignancy for alleviation of intractable pain .
described in this report is a case of a painful osteolytic vertebral metastasis that was successfully treated by a novel percutaneous vertebral augmentation system .
a 42-year - old caucasian female presented with a history of metastatic lung cancer unresponsive to radiation and chemotherapy with symptoms inadequately controlled by opiates over the previous 6 months . magnetic resonance imaging and spiral computed tomography with two - dimensional reconstruction showed an osteolytic vertebral metastasis with complete involvement of the t10 vertebral body , extending to the cortical vertebral wall anteriorly and posteriorly .
the patient was treated with percutaneous vertebral augmentation ( kiva vcf treatment system , benvenue medical , inc , santa clara , ca ) utilizing a novel coil - shaped polyetheretherketone implant designed to minimize the risk of cement extravasation .
after the minimally invasive procedure , bone cement distribution within the vertebral body was ideal , with no observed cement extravasation .
no complications were reported , pain completely resolved within 24 hours , and use of intravenous narcotics was progressively diminished within 1 week .
the kiva system represents a novel and effective minimally invasive treatment option for patients suffering from severe pain due to osteolytic vertebral metastasis .
if left untreated , progression of these lesions results in painful microfractures with potential for vertebral level collapse and spinal cord compromise .
open surgery for fracture stabilization is often inappropriate in this patient population due to a poor risk - benefit profile . given that the average life expectancy in patients with vertebral metastasis is 1 year,1 surgery is undesirable since the postoperative recovery consumes much of the remainder of life .
therefore , nonoperative and minimally invasive techniques are the most appropriate treatment options for vertebral metastases .
percutaneous vertebral augmentation is a minimally invasive procedure involving the injection of polymethylmethacrylate ( pmma ) into a vertebral body that is either partially collapsed or at high risk for collapse due to osteolysis .
vertebral augmentation is appealing as an adjunct to radiotherapy or chemotherapy in patients with malignancy for alleviation of intractable pain , despite comprehensive nonoperative management .
several studies have reported dramatic improvements in pain severity associated with osteolytic vertebral metastases following percutaneous vertebral augmentation.24 however , percutaneous vertebral augmentation is associated with higher risk of complications from pmma extravasation in cancer patients compared with osteoporotic patients due to loss of cortical integrity.5 as such , malignancy is widely considered a relative contraindication for these procedures . described in this report is the case of a painful osteolytic vertebral metastasis that was successfully treated by percutaneous vertebral augmentation using a novel coil - shaped polyetheretherketone ( peek - optima , victrex plc , lancashire , uk ) implant designed to minimize the risk of pmma extravasation .
a 42-year - old caucasian female was referred to our institution in june 2011 for evaluation of pain palliation using percutaneous vertebral augmentation .
the patient presented with a 4-year history of metastatic lung cancer unresponsive to radiation and chemotherapy , with symptoms inadequately controlled by opiates over the previous 6 months .
the patient reported pain severity of 10 on an 11-point visual analogue scale and back disability of 89% on the oswestry disability index .
magnetic resonance imaging and spiral computed tomography ( ct ) with two - dimensional reconstruction revealed an osteolytic vertebral metastasis with complete involvement of the t10 vertebral body , extending to the cortical vertebral wall anteriorly and posteriorly ( figure 1 ) .
immediately prior to the procedure , the patient was premedicated with intravenous antibiotics ( vancomycin hydrochloride 1 g and gentamycin 100 mg ) .
the patient was placed in the prone position on the table of the angiographic suite , and the procedure was carried out with digital hybrid fluoroscopic and ct guidance .
the entire procedure was performed under local anesthesia ( 3 ml of 2% lidocaine hydrochloride at the skin level and deep to include the periosteum ) along with continuous monitoring of vital parameters .
the peek implant is part of the kiva vcf treatment system ( benvenue medical , inc , santa clara , ca ) and is offered in a kit containing an access needle , kirschner guide - wire , dilator with working cannula , delivery system with nitinol coil guide - wire , and the implant bone cement and its manual screw injection system .
after a percutaneous approach was accomplished with an 11-gauge needle manually inserted through the costotransversal ( extra - pedicular ) route to reach the midline and close to the upper endplate of the t10 vertebral body ( figure 2a ) , a kirschner guide - wire was inserted to allow the placement of a 6-gauge working cannula ( figure 2b ) . through the 6-gauge introducer ,
the delivery system was inserted to allow the deployment of a nitinol coil - shaped guide - wire into the vertebral body ( figure 2c ) .
the kiva implant was then delivered over the nitinol guide - wire ( figure 2d ) inside the osteolytic lesion of the vertebra ( figure 2e ) to form a nesting , cylindrical column .
up to four loops of the implant may be inserted into the vertebral body for a maximum coil stack of 12 mm , which re - elevates the endplate .
after the coil was retracted , a total of 6 ml of radiopaque bone cement was gradually injected using a manual screw injector through the kiva implant and its inner holes under fluoroscopic monitoring ( figure 2f ) .
post - procedural ct scan with multi - planar reformatting demonstrated a satisfactory bone cement distribution within the vertebral body and the complete absence of extravasation either anteriorly or posteriorly ( figure 3 ) .
pain severity decreased from 10 to 0 within 48 hours , and analgesic opiate use was suspended . back
the patient was followed at 15 days , 1 month , 6 weeks , and 4 months post - treatment .
complete pain relief was maintained throughout 4 months of follow - up with no further need of analgesia .
further , previously radiated vertebral levels are at elevated risk for collapse , with potentially devastating neurologic consequences .
this case report shows that percutaneous vertebral augmentation using the novel coil - shaped peek kiva implant is feasible , effective , and may reduce the risk of pmma extravasation in the treatment of painful osteolytic vertebral metastases with diffuse cortical bone involvement .
the results of this report are novel in that the kiva implant represents a new therapeutic option for the treatment of painful vertebral metastasis where radiation therapy , traditional surgical stabilization , or balloon - based vertebral augmentation procedures may be contraindicated . chew et al3 conducted a systematic review on the safety and efficacy of percutaneous vertebral augmentation for spinal metastases and myeloma .
although vertebral augmentation reduced pain severity by 47%87% , serious complications were reported in up to 12% of patients .
the risk of cement extravasation is also notably higher in malignancies due to high vascularization and osseous destruction.5 resulting complications may include intercostal neuralgia , radiculopathy , myelopathy , or spinal infections.6 the kiva system was designed to reduce and stabilize vertebral fractures by deploying a coiled peek implant , which is then augmented with cement .
pmma bone cement is injected through the lumen of the kiva implant , which helps to contain and control the distribution of the cement .
once cured , the cement interlocks the implant to the cancellous bone . with traditional kyphoplasty and vertebroplasty procedures ,
pmma is injected into cancellous bone , but there is no mechanism for cement containment .
consequently , pmma cement may leak laterally to the soft tissues , superiorly or inferiorly into the adjacent disc space , or posteriorly , where it may involve the exiting nerve root or the spinal canal.6 a recent clinical study was conducted with the kiva system in 26 patients ( 42 fractures ) for treatment of vertebral compression fractures.7 anterior cement extravasation was identified at 4.8% of levels with no reported intracanal extravasation or adverse clinical sequelae .
these results compare favorably to cement extravasation rates of 7%72% reported in previous studies.812 the mechanism of pain amelioration with percutaneous vertebral augmentation is currently unknown , although two main hypotheses prevail .
polymethyl methacrylate cement stabilizes vertebral microfractures , which eliminates painful vertebral body and periosteal micromovements.13 in addition , the thermal polymerization of pmma following injection ablates pain receptors in trabecular bone , in vertebral periosteum , and in vascular structures.14 the combination of these two proposed factors leads to immediate postoperative anterior column stability and pain relief.4
the kiva system represents a novel and effective minimally invasive treatment option for patients suffering from severe pain due to osteolytic vertebral metastasis .
the novel design of the kiva implant may reduce the risk for pmma extravasation versus traditional vertebral augmentation procedures .
prospective studies are needed to validate the safety and effectiveness of this device in patients with vertebral metastasis .
written informed consent was obtained from the patient for publication of this case report and accompanying images .
 introductionvertebral metastases are associated with significant pain , disability , and morbidity . 
 open surgery for fracture stabilization is often inappropriate in this population due to a poor risk - benefit profile , particularly if life expectancy is short . 
 percutaneous vertebroplasty and kyphoplasty are appealing adjunctive procedures in patients with malignancy for alleviation of intractable pain . 
 however , these patients have higher risk of serious complications , notably cement extravasation . 
 described in this report is a case of a painful osteolytic vertebral metastasis that was successfully treated by a novel percutaneous vertebral augmentation system.case presentationa 42-year - old caucasian female presented with a history of metastatic lung cancer unresponsive to radiation and chemotherapy with symptoms inadequately controlled by opiates over the previous 6 months . magnetic resonance imaging and spiral computed tomography with two - dimensional reconstruction showed an osteolytic vertebral metastasis with complete involvement of the t10 vertebral body , extending to the cortical vertebral wall anteriorly and posteriorly . 
 the patient was treated with percutaneous vertebral augmentation ( kiva vcf treatment system , benvenue medical , inc , santa clara , ca ) utilizing a novel coil - shaped polyetheretherketone implant designed to minimize the risk of cement extravasation . 
 after the minimally invasive procedure , bone cement distribution within the vertebral body was ideal , with no observed cement extravasation . 
 no complications were reported , pain completely resolved within 24 hours , and use of intravenous narcotics was progressively diminished within 1 week . 
 complete pain relief was maintained throughout 4 months of follow-up.conclusionthe kiva system represents a novel and effective minimally invasive treatment option for patients suffering from severe pain due to osteolytic vertebral metastasis . 