Gasless Endoscopic Thyroidectomy via the Trans-Axillary Approach

Summary

This protocol presents the procedure for conducting thyroidectomy using the gasless endoscopic thyroidectomy trans-axillary approach (GETTA).

Abstract

For patients with early, low-risk papillary thyroid carcinoma, an increasing number are opting for endoscopic thyroid surgery due to its ability to achieve favorable therapeutic outcomes while maintaining excellent cosmetic results. Among the available endoscopic procedures, the Gasless Endoscopic Thyroidectomy Trans-axillary Approach (GETTA) has gained popularity among surgeons. This is attributed to its straightforward cavity construction, spacious operating area, precise visual field exposure, and manageable learning curve. However, few studies have provided detailed descriptions of the specific surgical steps involved in GETTA. Drawing from a synthesis of existing literature and our own clinical expertise, we present a comprehensive outline of the GETTA procedure. This process can be categorized into five distinct stages: positioning and incision planning; establishment of surgical cavities; identification and protection of the recurrent laryngeal nerve, inferior parathyroid gland, and central neck dissection; localization and preservation of the superior laryngeal nerve, superior parathyroid gland, and dissection of the thyroid’s superior pole; transection of the thyroid isthmus followed by en bloc resection of the thyroid gland and central neck lymph nodes. The five-step approach of GETTA is easy to learn and can be adapted for resecting both benign and malignant thyroid and parathyroid diseases.

Introduction

The recent increase in the incidence of papillary thyroid microcarcinoma (PTMC)^1,2, predominantly affecting young women, necessitates advancements in surgical techniques that offer both medical effectiveness and aesthetic sensitivity^3,4. The primary goal of the Gasless Endoscopic Thyroidectomy Trans-axillary Approach (GETTA), introduced by Chung in 2004⁵, is to provide an optimal surgical method that marries these two needs.

GETTA was developed as an answer to the drawbacks of traditional open surgery, such as noticeable scars leading to patients' self-consciousness and potential negative impact on their work and social activities. Endoscopic thyroid surgery has been gradually applied in the treatment of benign and malignant thyroid diseases^3,4, offering a less invasive alternative to open surgery. Yet, the innovation of GETTA lies in its unique gasless approach. The GETTA procedure holds several advantages over alternative techniques. It establishes the cavity through the natural folds of the axilla, rendering the incision hidden and yielding superior postoperative cosmetic results⁶. Moreover, GETTA omits the need for CO₂ gas inflation during the operation, thereby averting complications related to CO₂ gas. Furthermore, this approach leaves the anterior neck flap intact, which protects the function of the anterior cervical region post-surgery and prevents postoperative swallowing skin-tracheal linkage^6,7.

The technique is situated within the wider body of literature concerning endoscopic thyroid surgery. While there are ample research reports on the transoral and breast approach of endoscopic thyroid surgery^8,9, non-inflatable thyroid surgery remains underreported^10,11. Consequently, this method constitutes a significant contribution to this field, providing a comprehensive protocol for the GETTA procedure.

For readers contemplating the application of this method, it is most suitable for early-stage, low-risk papillary thyroid carcinoma patients who desire minimal scarring post-surgery. However, the success of this technique depends on the practitioner's proficiency in endoscopic procedures due to its spatial constraints. As such, the method may not be appropriate for practitioners without advanced endoscopic skills or those in medical centers with limited access to the necessary equipment.

This article aims to bolster the understanding of the GETTA procedure, offering insights into its application, and hopefully promoting its adoption in more medical centers. The benefits of GETTA extend beyond medical effectiveness, meeting patients' desire for less invasive surgery with favorable cosmetic results.

Protocol

This study was conducted in strict accordance with the ethical principles outlined in the Declaration of Helsinki and adhered to the guidelines established by our institution's Human Research Ethics Committee. The research protocol underwent a thorough review and received approval from the Ethics Committee of West China Hospital of Sichuan University. All participating patients provided written informed consent before their involvement in the study, and stringent measures were taken to ensure the privacy and confidentiality of their data throughout the research process. Patients with benign thyroid nodules, follicular neoplasms, or papillary microcarcinomas, with a tumor size of less than 2 cm, and the absence of lymph node metastasis, were included in the present study. On the other hand, patients with advanced thyroid cancer, tumors larger than 2 cm, evidence of lymph node metastasis, a history of neck surgery that might have resulted in anatomical distortions, or severe comorbidities were excluded from this study.

1. Initiation of the procedure

1. Administer general anesthesia to the patient using standardized techniques performed by a qualified anesthetist (following institutionally approved procedures). Employ the EMG Endotracheal tube (see Table of Materials). Preoperative antibiotics are not required.
2. Position the patient in a supine position, turning their head slightly to the unaffected side. Abduct the upper limb on the affected side to an angle between 60°-90°. This positioning helps expose and stabilize the axilla.

2. Incision making

1. Identify the first or second natural crease line in the axilla on the affected side. Make a primary incision of approximately 4-6 cm in length using a scalpel.
2. Create a secondary incision of about 0.5 cm using a surgical scalpel for Trocar (see Table of Materials) placement (Figure 1A).

3. Creating surgical cavities

1. Begin creating a nearly quadrilateral subcutaneous tunnel using retractors (see Table of Materials). Place the retractors on the surface of the pectoralis major muscle and lift the skin and subcutaneous tissue with them (Figure 1B).
2. Use the retractors to identify the gap between the sternal head of the sternocleidomastoid and the clavicle head (Figure 1C). Coagulate the tiny blood vessels in the gap using the mini button of the ultrasonic scalpel (see Table of Materials).
3. With dissecting forceps and the ultrasonic scalpel, dissect the anatomical space between the sternothyroid muscle and the internal jugular vein. Follow this anatomical space to locate the thyroid and coagulate the middle thyroid vein using the mini button of the ultrasonic scalpel.
4. Proceed to dissect the natural space between the thyroid and the sternothyroid muscle, place the retractors in this space, and complete the creation of the surgical cavities (Figure 1D).

4. Recognition and safeguarding of the recurrent laryngeal nerve, inferior parathyroid gland, and central neck dissection

1. Lift the middle and lower pole glands of the thyroid using the retractor to expose the tracheoesophageal groove.
2. Locate the recurrent laryngeal nerve around the bifurcation of the inferior thyroid artery, using a nerve monitoring probe (see Table of Materials) for confirmation⁹ (Figure 2A).
3. Carefully dissect the recurrent laryngeal nerve with dissecting forceps and the ultrasonic scalpel until it enters the larynx (Figure 2B). The length of the dissected nerve typically ranges from 4-6 cm, depending on the patient's anatomy and disease characteristics.
4. Dissect the area around the inferior thyroid artery using dissecting forceps and the ultrasonic scalpel while protecting and coagulating the inferior thyroid blood vessels with the mini button of the ultrasonic scalpel to expose the trachea.
5. Follow the nerve path to the larynx, ensuring its protection during the dissection process, after coagulating and cutting off the branches of the inferior thyroid artery (Figure 2C). Safeguard the inferior parathyroid gland, preventing any damage or removal during the thyroid and central neck lymph node dissection. If the blood supply to the inferior parathyroid gland is compromised, perform autologous transplantation¹².
6. Perform a central neck dissection method similar to open surgery¹². Remove lymph nodes from the central compartment of the neck based on the extent of the patient's disease (Figure 2D).

5. Identification and protection of superior laryngeal nerve and superior parathyroid gland and dissection of the superior pole of the thyroid

1. Lift the upper pole of the thyroid using retractors and separate it upward along the common carotid artery using dissecting forceps and the ultrasonic scalpel. Continue separation along the cricothyroid space to expose the vessels of the upper thyroid pole (Figure 2E).
2. Locate the superior laryngeal nerve using a nerve monitoring probe and intraoperative neuromonitoring (IONM) device¹³ (see Table of Materials).
3. Coagulate and cut off the blood vessels of the upper pole of the thyroid using the mini button of the ultrasonic scalpel, taking care to avoid coagulating or cutting the superior laryngeal nerve. Fully dissociate the gap between the upper pole of the thyroid gland and the cricothyroid muscle (Figure 2F).
4. Attempt to preserve the upper parathyroid gland in its original position while separating the upper pole of the thyroid gland. If the blood supply to the upper parathyroid gland is compromised, perform autologous transplantation¹².

6. En Bloc resection of the thyroid and central neck lymph nodes

1. Utilize an ultrasonic scalpel to coagulate tiny blood vessels, and then remove both the thyroid isthmus and the lymph nodes in the central area along with the thyroid gland (Figure 3A).
2. Collect the specimen using a specimen bag (Figure 3B).

7. Post-surgery procedures

1. Flush the operating cavity with warm sterile saline using a laparoscopic aspirator (see Table of Materials).
2. Position a drainage tube near the trachea, leading it out from the axilla using dissecting forceps (Figure 3C).
3. If needed, perform autologous transplantation of the parathyroid gland into the pectoralis major space following the method described in our previous work¹². The only difference is the change in the site from the sternocleidomastoid to the pectoralis major (Figure 3D).
4. Close the axillary incision using a 4-0 absorbable suture, making it 30 cm long and using an interrupted suture technique. Allow the neck muscles to naturally reset without suturing (Figure 3E).

Representative Results

In this study, a cohort of 200 female patients, all with a mean age of 36 years (SD = 4.52; ranging from 20 to 59 years), underwent the Gasless Endoscopic Thyroidectomy Trans-axillary Approach (GETTA) (Table 1). The patients had an average Body Mass Index (BMI) of 22.79 kg/m² (SD = 4.52; range = 18.27-27.31). The sonogram indicated an average tumor size of 7.09 mm (SD = 3.84). All patients were fully informed of the surgical options available and subsequently chose GETTA. Of the total, 54 (27%) patients had a history of operations and opted for GETTA to avoid keloid scarring. The remaining 146 (73%) patients primarily chose this approach due to aesthetic reasons.

Pathologically, 194 (97%) of the tumors were confirmed as papillary carcinoma, with the remaining 6 (3%) identified as follicular carcinoma. The location of the tumors was almost equally distributed between the left (92 patients, 46%) and the right (108 patients, 54%) sides of the thyroid gland. Most of the patients, 196 (98%), were in stage I of the TNM classification, with the remaining 4 (2%) in stage II. Parathyroid was auto-transplanted in 52 (76.5%) of the patients.

The surgery had an average duration of 96.12 min (SD = 26.13) with an average intraoperative blood loss of 6.32 mL (SD = 4.22). The average hospital stay was 6.04 days (SD = 0.87). Five patients experienced temporary recurrent laryngeal nerve signal weakening post-surgery, which resolved after a month. No cases of permanent recurrent laryngeal nerve injuries were observed. However, 3 patients required conversion to open surgery due to intraoperative bleeding, all of whom had benign thyroid nodules with large diameters.

Figure 1: Incision and surgical cavity creation. (A) Body position and incision design. (B) The first anatomical landmark: Sternocleidomastoid sternal head. (C) The second anatomical landmark: Scapula Hyoid muscle. (D) Completion of cavity construction. Please click here to view a larger version of this figure.

Figure 2: Sequential Steps in the surgical procedure. (A) Exposure of the tracheoesophageal groove. (B) Dissection of the recurrent laryngeal nerve. (C) Coagulation and cutting of the inferior thyroid blood vessels to expose the trachea. (D) Central lymph node dissection. (E) Probing of the superior laryngeal nerve. (F) Preservation of the upper parathyroid gland in situ. Please click here to view a larger version of this figure.

Figure 3: Resection and post-surgery procedures. (A) Amputation of the thyroid isthmus and en bloc resection of the thyroid. (B) Removal of the surgical specimen. (C) Rinsing with distilled water and placement of a drainage tube. (D) Transplantation of the parathyroid gland. (E) Suturing of the axillary incision. Please click here to view a larger version of this figure.

Variable			GETTA Patients
Age (year)		mean ± SD, range	36.07 ± 4.52 (20-59)
Gender		Female	200 (100%)
		Male	0
BMI (kg/m2)		mean ± SD	22.79 ± 4.52
		range	(18.27-27.31)
History of operation		Yes	54 (27%)
		No	146 (73%)
Sonogram tumor size (mm)			7.09 ± 3.84
Pathology		Papillary carcinoma	194 (97%)
		Follicular carcinoma	6 (3%)
Tumor Location		Left (n)	92 (46%)
		Right(n)	108 (54%)
TNM stage		I	196 (98%)
		II	4 (2%)
Parathyroid  autotransplantation		Yes	52 (76.5%)
		No	16 (23.5%)
Duration of the surgery (min)			96.12 ± 26.13
Intraoperative Blood loss (mL)			6.32 ± 4.22
Hospital stay (day)			6.04 ± 0.87
Temporary recurrent laryngeal nerve signal weakening			5
Permanent recurrent laryngeal nerve injuries			0
Conversion to open surgery			3
Data are presented as mean ± SD or number (%); SD: standard deviation, BMI: body mass index.

Table 1: Clinical characteristics and outcome of patients. Data are presented as mean ± SD or number (%); SD: standard deviation, BMI: body mass index.

Discussion

The Gasless Endoscopic Thyroidectomy Trans-axillary Approach (GETTA) is a novel surgical method that addresses the rising incidence of Papillary Thyroid Microcarcinoma (PTMC) while yielding aesthetically pleasing outcomes^14,15,16. Nevertheless, this technique requires a deep understanding of key operational steps¹⁷. Before commencing the actual surgery, surgeons are expected to familiarize themselves with the procedure by studying existing demonstrations provided by experts in the field¹⁶. The principal steps include creating an incision within the natural folds of the axilla to minimize visible scarring, establishing the operating space without CO₂ gas inflation, and carefully preserving the anterior neck flap to safeguard the function of the anterior cervical region post-surgery^18,19.

While the GETTA procedure offers several advantages, it also allows for customization based on individual patient circumstances or surgeon preferences¹⁶. Surgeons may need to adapt the approach when dealing with larger benign masses that could complicate the procedure due to limited operational space. Case selection plays a crucial role in mitigating these issues, with the recommendation being that beginners should choose early-stage PTMC patients with normal thyroid volume and without Hashimoto's thyroiditis¹⁵.

Despite its innovative benefits, GETTA has several limitations that must be considered. The technique demands advanced endoscopic skills and spatial proficiency, potentially limiting its accessibility in some medical settings. Effective implementation may be challenging in medical centers lacking the necessary equipment or training.

In comparison to traditional endoscopic thyroidectomy, GETTA represents significant advancements¹⁸. GETTA's incisions, concealed within the axilla's natural folds, offer markedly improved cosmetic results²⁰. Furthermore, by eliminating CO₂ gas inflation, GETTA reduces associated complications such as gas embolism, Subcutaneous Emphysema, and Cardiovascular Complications, demonstrating enhanced medical effectiveness²¹.

Looking ahead, the GETTA technique holds promising potential for broader applications^33,34. As surgical expertise grows and technology advances, it is plausible that adaptations of GETTA could further minimize invasiveness and recovery times. Wider implementation of GETTA would necessitate dedicated training programs to equip more surgeons with this technique, thereby increasing its global accessibility and utilization. This integration of aesthetic and functional considerations represents a promising path in the development of thyroid surgical techniques. Through ongoing research and application, GETTA could play an increasingly significant role in improving both surgical outcomes and patient satisfaction in the field of endoscopic thyroid surgery.

This study demonstrates that the gasless endoscopic thyroidectomy trans-axillary approach (GETTA) is a viable and safe technique for patients with early low-risk papillary thyroid carcinoma who wish to avoid a cervical scar. Compared with other endoscopic surgery methods, GETTA has distinctive characteristics for papillary thyroid carcinoma patients due to its unique approach and suspension method.

Materials

EMG Endotracheal Tube	Medtronic Xomed, Inc.	20173666541	EMG Endotracheal Tube
Forceps	Kangji Medical	106.890.A	Gasless endoscopic thyroidectomy trans-axillary approach Equipment (Within)
Gasless endoscopic thyroidectomy trans-axillary approach Equipment	Kangji Medical	106.890.A	Gasless endoscopic thyroidectomy trans-axillary approach Equipment
Intraoperative neuromonitoring (IONM) Device	Medtronic Xomed, Inc.	20083210370	NIM-Response 2.0
Laparoscopic aspirator	Kangji Medical	106.891.A	Gasless endoscopic thyroidectomy trans-axillary approach Equipment (Within)
Nerve monitoring probe	Medtronic Xomed, Inc.	20173666541	EMG Endotracheal Tube (Within)
Retractors (Two types)	Kangji Medical	106.890.A	Gasless endoscopic thyroidectomy trans-axillary approach Equipment (Within)
Trocar	Johnson & Johnson	B5LT	Trocar (5 mm)
Ultrasonic scalpel	Johnson & Johnson	HAR36	Ultrasonic scalpel