Gasless single incision trans-axillary thyroidectomy: The feasibility and safety of a hypo-morbid endoscopic thyroidectomy technique.

INTRODUCTION: A range of minimally invasive endoscopic techniques (gas dependent and gasless) have been attempted for thyroidectomy in the past two decades. In this context, we evaluated the feasibility and safety of our technique of a gasless trans-axillary thyroidectomy.
MATERIAL AND METHODS: This retrospective study from the Department of Endocrine and metabolic surgery in Southern India included 15 cases. The details of operative technique, intra and postoperative data were documented in all the cases. Only cases with benign thyroid nodules were included. Exclusion criteria were diffuse toxic goiters (Graves' disease), thyroid cancer, > 6 cm nodules, recurrent goitres and patients with shoulder joint pathology. Statistical analysis was done with SPSS software 12.0 version.
RESULTS: F:M -14:2. Mean age of the patient group was 26.4 years (15-52). Mean operative time was 123.4 (82-206) minutes. The only specific complications were induration in the infraclavicular area between axillary incision and thyroid region, prolonged wound drainage and stiffness in lower 3(rd) of sternocleidomastoid. Wound drainage lasted for 5.4 days (4 -8). There was no significant operative morbidity.
CONCLUSION: This gasless trans-axillary technique for nodular goitres is safe and effective in the hands of an experienced thyroid surgeon.

INTRODUCTION

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.[12345] The gas dependent techniques also lead to complications such as hypercarbia, subcutaneous emphysema, mediastinal emphysema, cardiac arrythmias etc.[67] in few cases. In this context, we evaluated our technique of a safer ET through trans-axillary route for its feasibility and safety.

MATERIAL AND METHODS

This is a retrospective study conducted in Endocrine and Metabolic Surgery department of a tertiary care teaching hospital in Southern India. The study cohort included 15 cases. Informed consent was obtained from all the patients. This study complied with the international ethical norms according to Helsinki Declaration-Ethical Principles for Medical Research Involving Human Subjects.[8] 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). Statistical analysis was done with SPSS software 12.0 version. Descriptive statistics were used to analyze the data.

Description of Operative Technique

In all the patients, procedure was performed under General inhalational anesthesia. Patient was placed in 20° reverse Trendelenberg position with neck extended. The ipsilateral arm was abducted to 90° and elbow flexed such that hand stays besides the head. The arm was padded and strapped in this position. The surface markings of relevant anatomical landmarks such as clavicle, anterior axillary line (AAL), sternocleidomastoid (SCM) and jugular notch were made [Figure 1].

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. Subfascial dissection was continued in subplatysmal plane above the clavicle. 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). [Figure 4] The inferior thyroid veins were clipped individually. Inferior parathyroid gland is secured during this step in most of the cases. For total thyroidectomy similar procedure was repeated on contralateral side. For hemithyroidectomy, ipsilateral goitre was resected after incising the isthmus, which was sutured in conventional way. The resected specimen was delivered through axilla. 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.

Figure 2

Intraoperative view I-approach to thyroid through sternomastoid muscle-sternal head (white arrow); clavicular head (black arrow)

Figure 3

Intraoperative view II-clipping of superior pole vessels (white arrow); superior parathyroid (black arrow); retracted strap muscles (hollow arrow over goiter)

Figure 4

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 patients were discharged after drain removal between 96 to 192 hours.

RESULTS

Gender distribution was F:M = 14:2. Mean age of the patient group was 26.4 years (15-52). Demographic and clinical details are shown in Table 1. 6/15 patients had compensated comorbidities such as diabetes, hypertension, chronic airway disease. At the time of surgery, all the patients were rendered euthyroid.

Table 1

Demographic and Clinical Profile

Operative, postoperative morbidity and histopathology details are shown in Table 2. Mean operative time was 123.4 (82-206) minutes. The only specific complications were induration in the infraclavicular area between axillary incision and thyroid region, prolonged wound drainage and stiffness in lower 3rd of sternocleidomastoid. Wound drainage lasted for 5.4 days (4 -8). There was no significant operative morbidity. 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].

Table 2

Surgical and post-operative details

Figure 5

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)

DISCUSSION

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.[9] 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.[12345] Even novel approaches such as thoracoscopic, robotic, trans-oral, post-auricular routes have been explored.[10111213] 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.[6714] 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. The subsequent scar is hidden in the axilla and remains under clothes. 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 1/3rd. 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, one can use endoclips and diathermy. All the haemostatic techniques such as direct knotting, diathermy, clips can be used complementarily and interchangeably as per surgeon's experience.

The axillary approach makes it difficult to visualize the opposite lobe. Sectioning 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. Gasless trans-axillary techniques have been reported in the past.[151617181920] Kang et al., described a similar technique, but employed a subcutaneous route with an additional 5 mm chest wall port. We found dissection in the subfascial plane is easier and associated lesser subcutaneous bruising. 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 is shown in Table 3.

Table 3

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, the drainage lasts for 36-48 hours. 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 1/3rd of SCM is probably due to splitting and dissection between its two heads. This lead to stiffness and pain in lower neck during turning of head. 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. Operative times and anaesthetic recovery are comparable to conventional technique. Thus, this technique combines the magnification of endoscopy and tactile sensation of open surgery. The technique is safe and effective in the hands of an experienced thyroid surgeon.

CONCLUSION

This study demonstrates the feasibility and safety of gasless trans-axillary endoscopic thyroidectomy technique for nodular goitres with usual general surgical risk.