Application of Endoscopic Aspirator on Gasless Transoral Endoscopic Thyroidectomy Vestibular Approach

doi:10.21203/rs.3.rs-3584369/v1

Background

Transoral endoscopic thyroidectomy vestibular approach (TOETVA) is gradually becoming mature.At the same time, the disadvantages of CO2 inflatable TOETVA are also widely recognized, and there is no uniform standard alternative.Here, we report our initial experience and discuss the safety and effectiveness of maintaining the operative space with endoscopic suction support in TOETVA.

Methods

We retrospectively analyzed 60 patients treated with our laparoscopic aspirator-supported TOETVA from March 2022 to June 2023.We extended the three-hole endoscopic suction device from the median incision of the oral vestibule into the operation space, pressed it down, and fixed it to support and maintain the stability of the space.Evaluate its surgical safety and prognosis.

Results

The study included 60 patients who were treated with endoscopic aspirator-supported TOETVA.The average operation time was 141. 14 ± 36. 15min.The average number of dissected lymph nodes was 4. 67 ± 3. 75.Two of them were converted to laparotomy, and no serious postoperative complications occurred in any of the patients.Postoperative complications included 1 case of transient recurrent laryngeal nerve paralysis, 1 case of transient hypoparathyroidism, and 8 cases of transient lower lip numbness.There was 1 case of postoperative skin injury and 4 cases of postoperative skin ecchymosis.Two cases of temporary loss of smell or taste recovered within 1–3 months.There is no evidence of specific complications associated with the use of suction to support the surgical space.

Conclusion

The operation space of TOETVA is supported by a laparoscopic suction device, which is easy to operate, convenient to obtain materials, and optimizes the clarity of the surgical field, which has the potential for wide application.

Thyroid cancer

Endoscopic thyroidectomy

Gasless TOETVA

Surgical instrument

Endoscopic Aspirator

Since Anuwong[1] first established and described the transoral endoscopic thyroidectomy vestibular approach (TOETVA) in 2016, the technology has gradually matured, providing surgeons with a clearer view of the surgery and an effective pathway to avoid scarring in the neck.Studies[2,3] have shown that compared with traditional open thyroidectomy (OT), transoral thyroidectomy has less trauma and postoperative pain for patients, and it also prevents the formation of postoperative scars.Compared with thyroidectomy by other approaches, TOETVA also has the advantages of less invasiveness and shorter surgical path[4].Despite the worldwide popularity of TOETVA, its disadvantages cannot be ignored, and one of the most serious complications is CO2 gas embolism due to the use of CO2 to maintain the workspace.In addition, CO2 entering the circulation can also cause complications[5] such as mediastinal emphysema, subcutaneous emphysema, pneumothorax, and hypercapnia.

In response to this, our group creatively used a laparoscopic aspirator instead of CO2 to support the surgical access.The operating space constructed with the suction device is not only very stable but also reduces the interference of smoke generated during the operation, greatly clarifying the surgical field of vision.Here, we summarize our initial experience and discuss the efficacy and safety of this technical.

Study population

We retrospectively analyzed 60 patients who underwent endoscopic aspirator-supported TOETVA from March 1st, 2022 to June 1st, 2023 in Chengdu Third People's Hospital.All patients were informed about the surgical procedure and signed consent forms before surgery.The same surgeon with experience in endoscopic thyroid surgery carried out each procedure. Written informed consent was obtained from each patient. The study was carried out with the approval of the Institution Review Board of the Third People's Hospital of Chengdu.

Inclusion criteria: (1) For benign nodules, the largest diameter ≤ 4 cm; (2) differentiated type thyroid cancer with a tumor diameter ≤2 cm and no lateral cervical lymph node metastasis or metastases to distant organs throughout the body, no imaging findings suggestive of central lymph node metastasis or metastases The diameter of the transferred lymph node is ≤2 cm; (3) patient willingness to pursue optimal cosmetic results.

Exclusion criteria: (1) oral conditions (oral deformities, local oral infections, etc. ) that restrict surgery or increase the risk of infection; (2) medullary carcinoma, undifferentiated thyroid; (3) prior history of neck surgery, ablation therapy, or neck radiation; and (4) other organ or system comorbidities that make it impossible to tolerate surgical trauma or general anesthesia.

Operative technique

30 minutes prior to the procedure, the patient was given 100ml of 0. 9% normal saline and 1. 0g of cefaclorin intravenously.A nasal cannula was used to administer general anesthesia.

The patient was placed in the supine position with a pad under the shoulders and the neck was slightly tilted back.After routine disinfection and draping, put a piece of saline gauze in the mouth to prevent aspiration.

Two 5mm incisions were made on both sides of the lower lip, and a 3cm median incision was made above the frenulum of the lower lip of the oral cavity to prepare for the establishment of the surgical gap.Make a sharp cut along the median incision to 0. 5cm from the tip of the mandible, then use scissors to bluntly separate the deep surface of the platysma muscle to the level of the hyoid bone along the incision, place a 12mm Trocar, and remove the rubber ring.Two 5mm Trocars were placed in the incision on both sides.Insert an endoscopic suction device with three holes (Fig. 1) on the right side of the 12mm Trocar, press down on the suction device, and fix it on the drapery, to establish and maintain the first space.All Trocar exhaust valves open to exhaust (Fig. 2).

Insert a 10 mm endoscope, insert grasping instruments and electric hooks or ultrasonic scalpels, and use electric hooks or ultrasonic scalpels to separate loose connective tissue.The lower limit is to the suprasternal fossa, and the two sides are limited to the front edge of the sternocleidomastoid.The suprasternal fossa is the lower end of the separation, and the ends on both sides are the anterior edge of the sternocleidomastoid.The linea alba was incised with an electric hook or an ultrasonic scalpel, and the anterior cervical muscles were bluntly separated to both sides to expose the thyroid tissue and common carotid artery, and a laparoscopic thyroid retractor was placed.The isthmus of the thyroid was severed with an ultrasonic scalpel to expose the trachea, the thyroid was lifted with non-invasive forceps, the superior thyroid artery was coagulated step by step, and the external branch of the superior laryngeal nerve was avoided.Use nerve detection forceps to determine the course of the recurrent laryngeal nerve and where it enters the larynx, carefully protect and separate the recurrent laryngeal nerve.The ligament of Berry was severed with bipolar electric coagulation forceps, the gland lobe was excised, and the gland was taken out for freezing during the operation.The appropriate central lymph node dissection was carried out if thyroid carcinoma was present.After the procedure, the surgical area was cleansed, the bleeding was carefully halted, and a submental drainage tube was inserted.The muscle layer of the median incision was sutured with 3-0 buckwheat interrupted, and the mucosal layer was sutured with buckwheat 4-0 fast.Antibiotics were used once after the operation, and liquid food was given 6 hours after the operation.

From March 2022 to June 2023, a total of 60 cases of endoscopic aspirator-supported TOETVA were performed in the Department of Breast and Thyroid Surgery of Chengdu Third People's Hospital.All patients were diagnosed as PTC by fine-needle aspiration before an operation, and preoperative preparations were perfected.Except for 2 cases that were converted to open surgery due to bleeding from innominate vein injury, the rest of the patients underwent successful surgery and recovered well after the operation.The general situation and disease characteristics of all patients are shown (Table 1).The age of all patients was 19-50 years old, with an average of (34. 29±8. 26) years old; the average BMI was 23. 27±3. 55kg/m².In terms of complications, 2 patients had hypertension, and the blood pressure was well controlled before surgery, and 34 patients had Hashimoto's thyroiditis; among the 60 patients, 2 had bilateral cancer, 6 had isthmus cancer, and the rest were unilateral cancer.

There are 3 surgical methods: 48 cases of lobectomy+central neck dissection (CND), 4 cases of total thyroidectomy+unilateral central neck dissection (UCND), and 8 cases of total thyroidectomy+bilateral central neck dissection (Table2).The operation time was 90-275 minutes, with an average of (161. 14±36. 15) minutes.The blood loss during the operation was 5-50ml, with an average of (9. 64±7. 27) ml.The average number of dissected lymph nodes was (4. 67±3. 75) and the number of metastatic lymph nodes was (0. 5±0. 88).The total postoperative drainage volume was (15-183) ml, with an average of (82±41. 47) ml, and the drainage time was 2-3 days, with an average of (2. 43±0. 51) days.One case was converted to OT during operation.All patients had no serious complications.1 case had skin damage after the operation; 4 cases had skin ecchymosis; 8 cases reported numbness of the lower lip, which recovered in about 3-6 months; 2 patients experienced a temporary loss of sense of smell or taste, all of which recovered within 3 months; 1 case of temporary recurrent laryngeal nerve paralysis; 1 case of temporary hypoparathyroidism.No CO2 gas embolism and postoperative bleeding occurred.They were hospitalized for 3 to 8 days after the operation and were discharged on average (3. 55±1. 21) days.The patients were followed up for 6 months after the operation.Both cases of recurrent laryngeal nerve paralysis and hypoparathyroidism were recovered.

Since it was originally developed and published in 2016[1], the transoral endoscopic thyroidectomy vestibular approach has gained popularity among surgeons. Considering the scars left after traditional open surgery, TOETVE can better meet the aesthetic needs of patients.Studies[2,3] have shown that patients who underwent TOETVE had less postoperative pain than patients who underwent open surgery.In addition to prolonging the operation time, intraoperative blood loss, the number of dissected lymph nodes, and hospital stays were not significantly different from those of open surgery.At present, there is no large-scale randomized controlled trial to verify whether laparoscopic thyroidectomy through the axillary and areola approach is better than TOETVA[6], but TOETVA still has the advantages of a shorter surgical path and no scar on the body surface.TOETVA will be a more acceptable surgical method for patients.In traditional TOETVA procedures, the workspace is maintained by infusing CO2[7].On the one hand, the working space of this method is a closed cavity, which leads to poor gas circulation, and the smoke generated during the operation cannot be effectively discharged, polluting the surgical field of view and disrupting the continuity of the operation.On the other hand, when the working space is established, due to continuous high pressure or blood vessel damage, especially veins, CO2 will be forced into the circulation with a small probability, causing CO2 gas embolism[5,7,8] to threaten the life safety of patients.This mechanism is also closely related to emphysema mediastinum, pneumothorax, and hypercapnia.Therefore, an air-free surgical method is urgently needed.

Nowadays, many surgeons have made efforts and attempts to perform air-free TOETVA.In recent years, Fang[9] et al.designed their own trocar and suspension system for TOETVA treatment without inflation.Their newly designed trocar removes the anti-leak valve, reduces the outer diameter, in order to reduce the interference of instruments during the operation, speeds up the air circulation, and improves the clarity of the operation space.And its suspension system uses two 1. 5mm Kirschner wires to penetrate the skin for suspension and fixation, which can provide more stability and a wider operating area.Jiang[10] et al.designed a novel workspace suspension system for airless TOETVA, which consisted of a set of self-developed retractors, sterile bandages, and an anesthesia rack.They hang the retractor directly on the anesthesia rack through a sterile bandage.This system has no special suspension system and is widely used.They also designed three types of retractors with different lengths to adapt to different patient neck lengths and the range of flaps that need to be separated, which is very ingenious.But whether this method will affect the function of the lower lip remains to be seen.It is also cumbersome to replace the three lengths of homemade retractors during the cavity construction process, and then adjust the corresponding lengths with sterile gauze to provide appropriate tension.

In this study, we inserted the endoscopic suction device into the cavity and pushed down the handle of the suction device to raise its head to support the surgical space, thus replacing the role of CO2 insufflation in the operation.This method is very simple and quick to operate, and not only avoids the risk of CO2 gas embolism but also accelerates the air circulation in the entire operating space through the suction generated by the endoscopic suction device during the operation.On the one hand, the suction device sucks away the smoke during the operation, greatly clearing the surgical field, and on the other hand, it also takes away the heat generated by the ultrasonic scalpel and electric scalpel, reducing the possibility of thermal damage to the nerves and trachea.Therefore, we chose a three-hole endoscopic aspirator instead of a two-hole endoscopic aspirator.During application, the three holes were exposed to the ventral surface to ensure the smoothness of the aspirator.Compared with traditional inflatable surgery, endoscopic aspirator-supported TOETVA also provides the surgeon with an additional vertical upward force during cavity construction, which increases the tension between the layers that need to be separated.This allows the operator to create the cavity more easily, thereby shortening the operation time, but at the same time, the operator needs to carefully judge the depth of the layer based on the image and the brightness of the light spot on the body surface from the laparoscope, so as to avoid damage caused by being too close to the skin.

However, our endoscopic aspirator-supported TOETVA still has shortcomings: (1) The surgical space established in the neck is very narrow, and an additional laparoscopic suction device is placed on the original basis, which increases the difficulty of the operation and requires higher operating requirements for the surgeon; (2) There is a mental nerve running in the mandible.Compared with TOETVA, the median incision made by endoscopic aspirator supported TOETVA is larger, and an additional laparoscopic suction device needs to be inserted, which increases the possibility of mental nerve injury during cavity construction, which will lead to It caused numbness or loss of sensation in the lower lip and jaw after surgery.We had 8 patients with this symptom, all of whom recovered within 3-6 months after surgery.Surgeons can avoid injury by exposing the mental nerve early.Among the 60 patients, the anatomical position of the innominate vein was higher than the normal level in 1 patient.The innominate vein was accidentally injured during the operation, resulting in a large amount of bleeding, so it was transferred to OT.The surgeon needs to carefully identify the anatomical structure of the innominate vein.Two cases experienced postoperative loss of sense of smell or taste, which gradually recovered within 1-3 months, which may be related to the use of propofol during anesthesia.With the increase in the number of operations, the operation time has been reduced from the initial 275 minutes to the current 90 minutes, the operation time has been greatly reduced, the proficiency of the surgeon is continuously increasing, and the learning curve is smooth.

The use of an endoscopic aspirator to maintain the surgical space in oral endoscopic thyroidectomy is not only very simple to use without the need for additional equipment but also can enhance air circulation and improve the clarity of the surgical field.Supporting the surgical space with a laparoscopic suction device appears to be safe and feasible, with the potential for widespread use in the future.

Abbreviations	Full name
TOETVA	Transoral endoscopic thyroidectomy vestibular approach
OT	Open thyroidectomy
BMI	Body Mass Index
CND	Central neck dissection
UCND	Unilateral central neck dissection

Disclosures Shuai Shao, Qinxin Zeng, Huimin Yu, Haobin Wang, Jian Wu, and Guoyang Wu have no conflicts of interest or financial ties to disclose.

Data availability statement

All data that support the findings of this study are included in this manuscript and its supplementary information files.

Ethics approval and consent to participate

The study was carried out with the approval of the Institution Review Board of the Third People's Hospital of Chengdu.

Author's Contribution

Study conception and desigh	Shuai Shao, Haobin Wang
Acquisition of data	Shuai Shao, Qinxin Zeng
Analysis and interpretation of data	Shuai Shao, Huimin Yu
Drafting of manuscript	Shuai Shao
Critical revision of manuscript	Haobin Wang, Jian Wu, Guoyang Wu

Shuai Shao and Haobin Wang contributed to the study conception and design. Material preparation, data collection and analysis were performed by Shuai Shao, Qinxin Zeng and Huimin Yu. The first draft of the manuscript was written by Shuai Shao and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

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Table 1 General clinical data
Variables	Value	Range/Percent
Age(mean,years)	34. 29±8. 26	19-50
Gender
Male	12	20. 00%
Female	48	80. 00%
BMI (kg/m2)	23. 27±3. 55	16. 78-32. 79
Comorbidity
Hypertension	2	3. 33%
HT	34	56. 67%
Number of cancer foci
Solitary	32	53. 33%
Multiple	28	46. 67%
Location
Left	24	40. 00%
Right	28	46. 67%
Bilateral	2	3. 33%
Isthmus	6	10. 0%
Tumor size(mean,mm)	0. 74±0. 35	0. 2-1. 7
T stage
T1a	13	21. 67%
T1b	47	78. 33%
N stage
N0	38	63. 33%
N1a	22	26. 67%
Preoperative TSH (mlU/L)	1. 99±1. 29	0. 08-5. 37
BMI body mass index, HT Hashimoto’s thyroiditis

Table 2 Surgical parameters
Variables	Value	Range/Percent
Extent of surgery
Lobectomy + CND	48	80. 00%
Total thyroidectomy + UCND	4	6. 67%
Total thyroidectomy + BCND	8	13. 33%
No.of dissected LNs (mean, piece)	4. 67±3. 75	1-17
No.of LN metastasis (mean, piece)	0. 5±0. 88	0-3
Operative time (mean, min)	141. 14±36. 15	90-275
Operative blood loss (mean, ml)	9. 64±7. 27	5-50
Total drainage amount (ml)	82±41. 47	15-183
Drainage time(d)	2. 43±0. 51	2-3
Postoperative hospital stay (d)	3. 55±1. 21	3-8
Conversion to open surgery	1	1. 67%
Complications
Skin damage	1	1. 67%
Skin ecchymosis	4	6. 67%
Temporary lower lip numbness	8	13. 33%
Temporary smell/taste disturbance	2	3. 33%
Temporary recurrent laryngeal nerve palsy	1	1. 67%
Transient hypocalcemia	1	1. 67%
Gas embolism	0	0. 00%
Postoperative bleeding	0	0. 00%
Hospital expenses (thousands yuan)	25. 62±3. 26	19. 35-31. 65
CND central neck dissection, UCND unilateral central neck dissection, BCND bilateral central neck dissection, LN lymph node

No competing interests reported.

Application of Endoscopic Aspirator on Gasless Transoral Endoscopic Thyroidectomy Vestibular Approach

Status:

Version 1

Abstract

Background

Methods

Results

Conclusion

Figures

Introduction

Materials and methods

Results

Discussion

Conclusion

Abbreviations

Abbreviations

Full name

Declarations

References

Tables

Additional Declarations

Status:

Version 1