Transoral thyroidectomy- Breaking new grounds??

Transoral thyroidectomy is the latest natural orifice approach to the thyroid which espouses cosmesis. The present issue of the journal has published an article which is a single-center initial experience in the Indian setting[1] using the standard three-port transvestibular technique with CO2 insufflation.

Innovation and progress are synonymous with human evolution. Evolution is important for survival and propagation. Surgery as a medical science has progressed with evolution of technology. The basic surgical tenets are enshrined and cannot change. However, new technology improves our ability to access, visualize, and resect safely while minimizing morbidity and improving outcomes. As in any technology adoption, the Rogers Curve[2] shows five stages from innovators, early adopters, early majority, late majority, and the laggards. The thyroidectomy saga has also advanced similarly. These surgeons[1] are early adopters of technology and from a tertiary referral centre; which augers well for teaching and training of future surgeons.

Minimally invasive video-assisted thyroidectomy popularized by Professor Paulo Micoli[3] from Italy brought into focus the last bastion which impeded the surgeon from doing the ultimate in surgery—a cosmetic expandable safe access. The only limitation remained the size of the thyroid gland with restrictions of 20 cc volume. The endoscopic transaxillary and bilateral axillary and breast access relocated the scar from the neck to the axilla. Robotic surgery using the axillary, breast, and retroauricular route improved control, vision, and reduced tremor and surgical stress. Thus, remote access surgery has become the standard of care for the cosmetically inclined patient and surgeon. The efforts to reduce access path to the thyroid evolved towards retroauricular robotic access,[45] which is currently the most commonly performed remote access thyroid surgery.

The concept of transoral thyroidectomy popularized by Dr. Angkoon Anuwong from Thailand[6] began with sublingual access but has now evolved into the safer transvestibular oral route, which the authors[1] have implemented in their series of 10 patients. There is a need to be judicious in case selection as can be seen in selection of thyroid lobes less than 4 cm in this case series. This seems to be a limitation because of the central port size which makes delivery of the dissected gland a challenge. The recommended method is to bag the gland and make incisions on it at 1.5 cm intervals to ease the delivery of the specimen through the central incision in a large benign goitre.[6]

The main issue in any thyroid surgery is the preservation of recurrent laryngeal nerve (RLN) and parathyroid glands and duration of the procedure. The authors[1] have shown surgical time to be an average of 75 min without damage to the recurrent laryngeal nerve or parathyroids. Although the authors[1] failed to identify the RLN in two of their patients; luckily, their surgical outcome was uneventful. This highlights the importance of adequate training before heading into this type of specialised surgery. The authors have themselves suggested that at least 50 cases might be required for a surgeon to master this type of minimal access surgery and that too should be performed under expert supervision.[1]

Transoral thyroidectomy seems to be a safe procedure with minimum morbidity as has been seen in this case series. The patients need to be carefully selected and there is no alternative to the learning curve. Endoscopic equipment being used are routinely available in any general setup and do not substantially increase costs to the patient. Concern for infection arises because of the transoral access which can contaminate the neck and require postoperative antibiotic cover. The procedure is still evolving and there is emerging literature on its safety in thyroid malignancy.[7] Surgical morbidity is a challenge and use of intraoperative nerve monitoring during transoral endoscopic thyroidectomy[8] will certainly improve the outcomes.

Future prospects

The single-port robot[9] with its 3 mm instruments will certainly give additional boost to the transoral route, further reducing the access incisions and instrumentation albeit at an additional cost to the patient. As in any technology, we should be scientific in evaluating the merits of the surgery. Transoral thyroidectomy seems to be a suitable surgery in select cases in experienced hands. Early adopters have begun and soon the early majority will practice it. Time is a great leveller and among the myriad of approaches available the best with highest efficiency and optimum cost-benefit ratio will become the gold standard.