in past three decades , minimal access and minimally invasive techniques have been firmly established in the field of surgery . though , initially it was restricted to abdominal and gynaecological surgeries , minimal access techniques have been employed in sub specialities in the latter period . similarly , thyroidectomy is not an exclusion to these minimally invasive approaches . various endoscopic thyroidectomy ( et ) techniques ranging from totally endoscopic , video- assisted , trans - axillary , chest wall approaches have been reported . the gas dependent techniques also lead to complications such as hypercarbia , subcutaneous emphysema , mediastinal emphysema , cardiac arrythmias etc . in few cases . in this context , we evaluated our technique of a safer et through trans - axillary route for its feasibility and safety . this is a retrospective study conducted in endocrine and metabolic surgery department of a tertiary care teaching hospital in southern india . this study complied with the international ethical norms according to helsinki declaration - ethical principles for medical research involving human subjects . the details of operative technique were documented and recorded in all the cases . only cases with benign thyroid nodules were included . exclusion criteria were diffuse toxic goitres ( graves disease ) , thyroid cancer , > 6 cm nodules , recurrent goitres and patients with shoulder joint pathology . all the cases were performed by the operative team -the primary operating surgeon ( os ) and two assisting surgeons ( as ) . the ipsilateral arm was abducted to 90 and elbow flexed such that hand stays besides the head . the surface markings of relevant anatomical landmarks such as clavicle , anterior axillary line ( aal ) , sternocleidomastoid ( scm ) and jugular notch were made [ figure 1 ] . surface markings for surgical procedure - axillary incision ( vertical arrow ) ; anatomical landmarks ( trasverse arrows ) a 4 - 5 cm long skin incision was used 1 cm posterior and parallel to aal . skin incision was deepened up to pectoral fascia . pectoral fascia was incised in the same line and sub - fascial dissection was performed by blunt digital and sharp instrumental dissection to create operative space . after initial dissection , subsequent dissection was done under telescopic guidance placed through the same incision and held by camera assistant ( ca ) . thus , dissection for operative space was done both under synergistic view of naked eye and monitor . the operating surgeon ( os ) and as stand on ipsilateral side of goitre to visualize the operative field through the axillary incision . thyroid bed was entered through the distal avascular area between the two heads of scm [ figure 2 ] . the sternal head of scm and strap muscles are retracted by as to the opposite side . while managing the clavicular head of scm , os retracts carotid sheath and superior vascular pedicle is ligated with conventional knotting or clipping individual vessels [ figure 3 ] . further medial mobilization of helps in visualizing and securing the recurrent laryngeal nerve ( rln ) and superior parathyroid gland ( ptg ) . ipsilateral goitre was resected after incising the isthmus , which was sutured in conventional way . a 14 fr suction catheter is placed in to thyroid bed and operative space through a separate stab wound in axilla . it was retained in situ till the drain output was less than 20 ml on two consecutive days with no erythema or bogginess in dissected area . intraoperative view i - approach to thyroid through sternomastoid muscle - sternal head ( white arrow ) ; clavicular head ( black arrow ) intraoperative view ii - clipping of superior pole vessels ( white arrow ) ; superior parathyroid ( black arrow ) ; retracted strap muscles ( hollow arrow over goiter ) intraoperative view iii - recurrent laryngeal nerve ( black arrow ) ; superior parathyroid ( lower end of double headed arrow ) ; suture being threaded to tie a branch of inferior thyroid artery ( hollow arrow ) post - operative period was uneventful in all the cases . the ipsilateral arm was abducted to 90 and elbow flexed such that hand stays besides the head . the surface markings of relevant anatomical landmarks such as clavicle , anterior axillary line ( aal ) , sternocleidomastoid ( scm ) and jugular notch were made [ figure 1 ] . surface markings for surgical procedure - axillary incision ( vertical arrow ) ; anatomical landmarks ( trasverse arrows ) a 4 - 5 cm long skin incision was used 1 cm posterior and parallel to aal . skin incision was deepened up to pectoral fascia . pectoral fascia was incised in the same line and sub - fascial dissection was performed by blunt digital and sharp instrumental dissection to create operative space . after initial dissection , subsequent dissection was done under telescopic guidance placed through the same incision and held by camera assistant ( ca ) . thus , dissection for operative space was done both under synergistic view of naked eye and monitor . the operating surgeon ( os ) and as stand on ipsilateral side of goitre to visualize the operative field through the axillary incision . thyroid bed was entered through the distal avascular area between the two heads of scm [ figure 2 ] . the sternal head of scm and strap muscles are retracted by as to the opposite side . while managing the clavicular head of scm , os retracts carotid sheath and superior vascular pedicle is ligated with conventional knotting or clipping individual vessels [ figure 3 ] . further medial mobilization of helps in visualizing and securing the recurrent laryngeal nerve ( rln ) and superior parathyroid gland ( ptg ) . a 14 fr suction catheter is placed in to thyroid bed and operative space through a separate stab wound in axilla . it was retained in situ till the drain output was less than 20 ml on two consecutive days with no erythema or bogginess in dissected area . intraoperative view i - approach to thyroid through sternomastoid muscle - sternal head ( white arrow ) ; clavicular head ( black arrow ) intraoperative view ii - clipping of superior pole vessels ( white arrow ) ; superior parathyroid ( black arrow ) ; retracted strap muscles ( hollow arrow over goiter ) intraoperative view iii - recurrent laryngeal nerve ( black arrow ) ; superior parathyroid ( lower end of double headed arrow ) ; suture being threaded to tie a branch of inferior thyroid artery ( hollow arrow ) post - operative period was uneventful in all the cases . 6/15 patients had compensated comorbidities such as diabetes , hypertension , chronic airway disease . at the time of surgery , all the patients were rendered euthyroid . demographic and clinical profile operative , postoperative morbidity and histopathology details are shown in table 2 . the only specific complications were induration in the infraclavicular area between axillary incision and thyroid region , prolonged wound drainage and stiffness in lower 3 of sternocleidomastoid . induration of infraclavicular area resolved at a mean of 20.7 ( 15 - 35 ) days and sternocleidomastoid induration at a mean of 36.5 ( 22 - 50 ) days in all the cases . all the patients had excellent cosmetic outcome with a hidden surgical scar in axilla [ figure 5 ] . surgical and post - operative details 12th post - operative day clinical photograph - no cervical scar ( white arrow ) ; axillary incision to be hidden by clothes ( lower black arrow ) ; induration in ipsilateral dissected area ( vertical arrow ) a glance at the history of thyroidectomy reveals how it was developed by pioneer endocrine and thyroid surgeons through various stages till the present era of minimal access surgery . though , open conventional thyroidectomy is still the favored approach worldwide , a plethora of endoscopic thyroidectomy ( et ) techniques ranging from totally endoscopic , video - assisted , trans - axillary , chest - wall approaches have been already employed . even novel approaches such as thoracoscopic , robotic , trans - oral , post - auricular routes have been explored . though none of them are validated universally , chest - wall and trans - axillary approaches are favoured by the majority . the objectives of any et technique are better cosmesis , lesser pain , lower morbidity and feasibility in patients with co - morbidities . most of available et techniques fulfill cosmetic and pain aspects , but fail to address the latter two aspects . based on use of gas ( co2 ) , et may be broadly divided in to gas dependent and gasless techniques . the gas dependent techniques can cause serious hypercarbia associated complications such as subcutaneous emphysema , mediastinal emphysema , cardiac arrhythmias and even death in few cases . especially , patients with comorbid conditions such as hypertension , diabetes and chronic obstructive airway disease are susceptible to the complications . these complications are related to co2 insufflation pressures , length of surgery , susceptibility and comorbid conditions of the patient . lower co2 insufflation pressures , intensive end tidal co2 monitoring ( etco2 ) , intra - operative arterial blood gas analysis ( abg ) , intermittent desufflation , shorter operative times , proper patient selection have been recommended to counter these gas related complications . on the contrary , gasless techniques are very safe as it nullifies the whole gamut of gas related morbidity . thus , even patients with well to moderately controlled comorbidities can be taken up for surgery and allows longer operative times with extra safety . it also reduces the cost of intensive etco2 and abg monitoring used for gas dependent techniques . the only practical disadvantage of gasless over gas dependent technique is inadequate operative space , which can be compensated by proper retraction by as and synergistic naked eye and camera vision of thyroid area . in conventional open approach , the gland is reached through a range of variably sized collar neck incisions in the neck , which can result in scar with hyperesthesia , paraesthesia and increased patient self - awareness . furthermore , keloid or hypertrophic scar worsens the cosmetic outcome , especially in dark skinned individuals . total et has reduced the level of surgical invasiveness with extra - cervical short incisions with superior cosmetic outcome , but is a gas dependent technique with its associated risk . the trans - axillary approach utilizes an access through the axilla , thus avoiding a cervical or chest wall incision . this is especially applicable in modern times , due to increasing use of low neck tops exposing the upper anterior chest wall , which is the surgical access area for et through chest wall . the position of the patient has great importance , as abduction of the arm and flexion of the elbow reduces the distance between the aal and the thyroid bed by almost 4 - 6 cm , ensuring easier accessibility of thyroid through axilla . pre - operative surface marking was very much useful in limiting dissection during creation of the space . the plane of dissection was confined below the pectoral fascia , which reduces the chances of skin burns due to electro - cautery and subcutaneous ecchymosis . the development of this natural plane was easier compared to traumatic dissection of subcutaneous space and beyond clavicle ; it was continued in to sub - platysmal plane . the use of telescope with magnified view on monitor with synergistic naked eye vision has a practical advantage ( vide infra ) . both steps are complementary , especially for identification and preservation of critical structures like rln and ptg . the entry in to the thyroid bed was through the two heads of scm which is a relatively avascular plane in the lower 1/3 . further , it reduces the morbidity related to strap muscle division . throughout the procedure it requires efficient retraction of the sternal head of scm along with strap muscles the as . thus it does not require co2 gas to maintain the working space for dissection and thus precludes its related morbidity . the dissection performed utilizes both open as well as laparoscopic instruments and the combines the advantages of both the techniques . maneuvering in the depth to ligate the superior pole by open knotting technique is one of the disadvantages for the surgeons with shorter fingers . in such situations , all the haemostatic techniques such as direct knotting , diathermy , clips can be used complementarily and interchangeably as per surgeon 's experience . the sternohyoid muscle to create a good visual space even for the contralateral lobe dissection has been described , but has disadvantage of prolonged operative time and post - operative neck pain with discomfort while swallowing . to counterbalance this situation , we employed a similar procedure on contralateral side through its corresponding axilla for total thyroidectomy . this bilateral axillary approach for total thyroidectomy was not associated with any extra morbidity compared to unilateral approach and ensures better identification of rln and ptg on both sides . kang et al . , described a similar technique , but employed a subcutaneous route with an additional 5 mm chest wall port . holsinger et al . and landry et al . , described a robotic technique with similar approach , but are feasible in very few centers in near future . though , it increases the area of dissection in infra - clavicular region , it compensates with better post - operative cosmetic result . comparision between various studies of trans - axillary thyroidectomy the three notable morbidities , we observed with this technique are prolonged drainage ( mean : 5.4 days ) , induration of lower part of scm and induration of infraclavicular area . infraclavicular induration is evidently due to larger area of dissection compared to conventional thyroidectomy , through neck and lymphatic plexuses in subpectoral mammary area . in our experience , with conventional thyroidectomy though , we did not perform formal analysis of this variable in the present study , this observation is significant enough to investigate further as it prolongs hospital stay . the increased seroma rates in other studies might be due to earlier drain removal or understatement , as we found wound drainage lasted for longer duration than the hospital stay in those studies . induration of lower 1/3 of scm is probably due to splitting and dissection between its two heads . though , it was self - limiting , it appears to be a unique complication specific to gstat . induration of ipsilateral infraclavicular area corresponded to the dissected area between axillary incision and thyroid bed . similar to scm induration , this was self - limiting and unique to gstat , although of shorter duration than the former . in an effort to obviate the adverse aesthetic and morbid effects of conventional open surgical technique and gas dependent et techniques , we employed this gasless single incision trans - axillary thyroidectomy ( g - stat ) . the basic sequence of steps in the procedure is nearly identical to a conventional open thyroidectomy . an endoscope provides excellent lighting and magnification , thus the entire surgical team can see the structures and procedure better than in a conventional open procedure . thus , this technique combines the magnification of endoscopy and tactile sensation of open surgery . this study demonstrates the feasibility and safety of gasless trans - axillary endoscopic thyroidectomy technique for nodular goitres with usual general surgical risk .