Robotic thyroid surgery using bilateral axillo-breast approach: From a trainees' point of view.

BACKGROUND: Across surgical disciplines, the demand for cosmetically superior procedures is stronger than ever and patient-centered health care has become the standard of care. Endoscopic thyroidectomy has revolutionized the field of minimal access endocrine surgery and akin to other surgical disciplines, there has been a natural progression towards robot-assisted thyroidectomy. Amongst the many described approaches, bilateral axillo-breast approach (BABA) and transaxillary are most widely practiced. AIMS AND
OBJECTIVES: Our aim was to describe the technique of robot-assisted thyroid surgery (RATS) using BABA.
METHODS: This is based on the corresponding authors' training and experience of over 50 cases of RATS using BABA, at the Seoul National University, Republic of Korea.
RESULTS: Post-operative outcomes were excellent with lesser pain, better cosmesis and similar oncological outcomes in carefully selected thyroid cancers in comparison to conventional thyroidectomy.
CONCLUSION: RATS using BABA is easy to master for endoscopic thyroid surgeons and offers excellent postoperative outcomes, ergonomics, vision and dexterity.

INTRODUCTION

The past two decades have witnessed a rapid emergence and acceptance of several scarless (in the neck) endoscopic thyroidectomy (ET) techniques.[12] Like other surgical disciplines, the natural evolution is to foray into robotic procedures. Robot-assisted thyroid surgery was pioneered and validated by endoscopic surgeons from Korea. The most common approaches are transaxillary gasless approach described by Chung et al. from South Korea[34] and bilateral axillo-breast approach (BABA) by Choe et al. and Lee et al. from Seoul National University Hospital.[56] They initially developed BABA for ET and subsequently combined it with the surgical robot system. This synergised their advantages: the unique surgical approach (BABA) which simulates conventional surgery and the da Vinci System which incorporates high-definition 3D imaging, endo-wrist function, easy manipulation and short learning curve.[67] The author (GC) underwent this training at Seoul National University Hospital for 6 months, and this article summarises the technique of robotic BABA procedure from a trainee's perspective.

INDICATIONS

Same as ET, however, currently, no standard selection criteria have been established.[8] Absolute contraindications are previous neck surgery/irradiation, extensive retrosternal extension and locally invasive cancers. Relative contraindications include extremes of age, morbid obesity and very large goitres.[6]

PREOPERATIVE PREPARATION

Same as conventional thyroidectomy

Same as conventional thyroidectomy which includes: biochemical thyroid profile, neck ultrasonography, FNAC from thyroid nodule and vocal cord evaluation. Also, optimisation of hypo/hyper-thyroidism and any chronic cardiovascular and/pulmonary conditions. In addition, a clinical breast examination is mandatory to screen for pre-existing breast lumps/lesions and mammography/sonographic evaluation in female patients.

SURGICAL TECHNIQUE

Instruments

The basic requirement is da Vinci robotic system [Figure 1a] with 3D telescope, light source system and vessel sealing and cutting energy devices, gas insufflators and robotic ports and hand instruments [Figure 1b and c]. Intraoperative neuromonitoring (IONM) system is preferable for recurrent laryngeal nerve (RLN) monitoring.

Figure 1

Da Vinci Robot with arms (a), robotic ports (b) and hand instruments (c)

ANAESTHESIA

All procedures are done under General anaesthesia using flexometallic endotracheal tube/IONM tube (if available).

POSITION

The patient is in reverse Trendelenburg position (supine with 30° head end elevation) with a customised tapered sandbag [Q-Pillow, Figure 2] under the shoulders for optimal neck extension and head support. The arms are kept slightly abducted at the shoulders and flexed at elbows. This opens up the axillae and allows movement of axillary trocar [Figure 3]. Chlorhexidine/povidone–iodine solution is used for sterile preparation (chin to umbilicus and axillae).

Figure 2

Q-Pillow, a customised tapered sandbag placed under patient's shoulders which aids in optimal neck extension and head support

Figure 3

Final patient position after placement of Q-pillow (Reverse Trendelenburg: supine with 30° head end elevation)

SKIN MARKINGS

Important anatomical landmarks are shown in Figure 4. The boundaries for skin flap dissection are marked by two curved lines: one, about 4 cm inferior and parallel to both clavicles and the other connecting superior border of thyroid cartilage to lateral ends of either clavicle.

Figure 4

Skin markings for flap dissection, port placement with important anatomical landmarks

Port site markings are: a 12 mm port, 12–3 o'clock circumareolar position on the right breast and 8 mm port, 9–12 o'clock position on the left. Port site markings are: a 12 mm port, 12–3 o'clock circumareolar position on the right breast; 8 mm port, 9–12 o'clock position on the left and two 8 mm ports in bilateral axillae along the most prominent axillary fold. Four straight (trajectory) lines are drawn from these incision markings directed towards the thyroid cartilage.

PORT PLACEMENT AND CREATION OF SUBCUTANEOUS FLAPS

1:200,000 adrenaline (Adr):normal saline (NS) (1 ml Adr in 200 ml NS) solution is infiltrated in subplatysmal plane in the neck and subcutaneous plane over the chest using 18G spinal needle [Figure 5]. This aids in hydrodissection and minimises blood loss during dissection.

Figure 5

infiltration of adrenaline normal saline into subplatysmal plane in the neck and chest using 18G spinal needle and 10cc syringes

Incision for the 12 mm port is placed and deepened using electrocautery followed by blunt dissection using straight haemostat forceps, making a subcutaneous tunnel guided by the trajectory lines [Figure 4]. The same steps are repeated on the left breast for 8 mm port.

Next, a vascular tunneler is inserted along these tunnels to create a subcutaneous plane between the two curved lines over the chest. As this is a blind procedure, after completion, a sponge is rolled over the area to squeeze out any liquefied fat and look for significant bleeding. The 12 mm port is placed and CO2 insufflation started (maintaining pressure at 6–7 mmHg with flow rate 15–20 L/min) and the telescope is inserted. Next, 8 mm port is placed and connected to a 14G needle (for intermittent suction) and harmonic scalpel is inserted. The remaining flap is created under vision. After further dissection, 8 mm incision is made in the right axillary fold, a subcutaneous tunnel is created, port placed then harmonic scalpel is shifted to this port. 14G needle is replaced with intermittent suction catheter. Dissection is continued towards left axilla, and once adequate, the 8 mm port is placed and suction tube is passed through it. Final port placement is shown in Figure 6.

Figure 6

Final port placement

SUBPLATYSMAL NECK FLAP

Next, dissection is directed towards the subplatysmal flap, using two dissecting forceps through axillary and harmonic scalpel through left breast port. Boundaries of dissection are superiorly, upper border of thyroid cartilage and laterally, lateral border of sternocleidomastoid (SCM). The dissecting forceps help in lifting up the flaps and countertraction.

DOCKING

Operating table's foot end is raised by 5° and head end by 10°, and patient cart is positioned near it. Centre column is aligned and camera arm of robot with the camera port on the right breast over the patients' left shoulder. Robotic arms of patient cart are positioned high and cleared over patient's head and operating table. Overhead lights, beams and equipment are pushed aside to prevent contamination of patient cart. Nipple-areola complex is protected by applying extra thin hydrocolloid dressing as seen in Figure 7 (e.g., DuoDERM), and breasts are strapped with wide tape to prevent hanging and displacement of breast ports. Figure 8 shows the final setup after docking. After this, the surgeon operates from the console.

Figure 7

Extra thin hydrocolloid dressings applied for protection of nipple-areola complex

Figure 8

View after docking of robot

DIVISION OF MIDLINE AND LATERAL DISSECTION

Midline is identified and opened using electrocautery hook (strap muscles are held up with graspers to aid dissection). The cricothyroid membrane, thyroid isthmus and trachea are identified, and isthmus is bisected in the midline. For isthmic nodules, the gland is bisected along para-isthmic lines.

For total thyroidectomy, the side with larger or malignant nodule is handled first. Isthmus is dissected off from trachea and cricothyroid muscle and pulled to opposite direction using graspers. Thyroid lobe is then separated from deeper layer of strap muscle (retracted laterally with dissector) and pulled medially to create lateral thyroid space.

IDENTIFICATION AND PRESERVATION OF RECURRENT LARYNGEAL NERVE AND PARATHYROID GLANDS (PTH)

After creating lateral thyroid space, an effort is made to identify the tubercle of Zuckerkandl as RLN lies posterior to it. The nerve can be confirmed using IONM. Following this, lower pole is dissected and inferior parathyroid hormone (PTH) identified and preserved and inferior thyroid vessels secured. Dissection continues from below upwards, along the RLN till ligament of Berry.

DISSECTION OF UPPER POLE AND SPECIMEN EXTRACTION

RLN is separated from Berry's ligament, and the gland is rotated medially to visualise superior PTH and secure upper pole vessels. Superomedially, external branch of superior laryngeal nerve is preserved and the lobe is dissected from cricothyroid muscle. Finally, the pyramidal lobe is dissected till the hyoid bone and specimen divided. It is placed in an endobag and extracted through left axillary incision. Specimen should be inspected ex vivo, and if doubtful for malignancy, a frozen section biopsy is requested. Figure 9 shows the endoscopic view of salient surgical steps.

Figure 9

Endoscopic view showing important surgical steps as described in the text

DISSECTION OF CONTRALATERAL LOBE AND CENTRAL COMPARTMENT LYMPH NODE

If the frozen section shows malignancy, contralateral lobectomy is performed in a similar manner along with central compartment lymph node (CCLND) depending on the size of tumour.

CCLND is performed using monopolar hook, starting near the trachea towards sternal notch, dissecting medial to lateral around RLN. Throughout dissection, RLN is protected by placing a rolled gauze ball over it. Inferior PTH is dissected off laterally to safeguard vascularity. In case of accidental devascularisation or removal with specimen, autotransplantation in ipsilateral SCM or pectoralis major muscle (through the port site incision) is advisable.

CLOSURE

Cavity is irrigated and haemostasis ensured. A haemostatic agent (fibrin sealant/SURGICEL) is placed in the bed. Absorbable antiadhesive barrier agents (e.g., INTERSEED, Ethicon) may be used to prevent adhesions between trachea and strap muscles. Midline is approximated using 2-0 polyglactin. 12F negative suction drain is placed under the straps and taken out from left axillary incision site. Robot is undocked and trocars removed sequentially under vision, telescope being the last.

Port sites are closed with 4-0 polyglactin, subcuticular, interrupted suture and reinforced using Steri-Strips. After over padding port sites and chest, a customized pressure dressing (BABA brassiere) is applied [Figure 10]. Patient is reversed and transferred to recovery room.

Figure 10

Custom-made breast support or bilateral axillo-breast approach brassiere. A tight compression or crepe bandage can be served as a good substitute

POST-OPERATIVE CARE

Similar to conventional surgery with the added advantage of no routine prescription for analgesics. Nonsteroidal anti-inflammatory drugs/opioid analogues are given on demand. BABA brassiere is kept for 24 h then pressure is reduced by half. Post-total thyroidectomy, serum calcium is monitored for 2 days, and if no clinical hypocalcaemia, patients are discharged on 3rd day after drain removal. Dressing is removed on 1st post-operative visit. Women are advised to wear BABA brassiere for 1st month postoperatively.

In the author's opinion, post-operative outcomes of BABA robotic thyroid surgery were excellent in comparison to conventional thyroid surgery with respect to lesser post-operative pain, better cosmetic and similar oncological outcomes in carefully selected thyroid cancers. This has also been validated by several studies.[9] Furthermore, being skilled in BABA for ET before this training, the author felt that learning robotic surgery was much quicker and easier. It also offers the surgeon excellent ergonomics, vision and dexterity; however, the cost of robotic surgery is much higher.[910]

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.