Introduction
Open thyroidectomy incorporated a midline skin crease was first popularized by Kocher in 1906; since that time it has remained the standard surgical technique for thyroidectomy. This approach provides the most direct route to the thyroid bed and offers complete visualization of the surgical field. Therefore it results in excellent, predictable, and reproducible clinical outcomes with consistent preservation of the parathyroid glands and recurrent laryngeal nerves (RLN).
Gaining access to the thyroid bed from a remote site was made possible with the recent development of the da Vinci robotic system (Intuitive Surgical Inc., Sunnyvale, California). There are two approaches to the thyroid bed during robotic thyroidectomy. The first approach accesses the thyroid bed from the lateral direction by entering the bed between the anterior border of the sternocleidomastoid muscle and the sternothyroid muscle. This is accomplished either by way of the transaxillary (TA) or retroauricular (RA) approach. The former method was described first by Chung et al. and has been widely adopted as a single-incision gasless approach to the thyroid bed from the axilla. The RA, or modified facelift technique, was first described by Terris et al. and has become a popular remote access to the neck for robotic-assisted approaches. Byeon et al. recently demonstrated an acceptable cosmetic outcome with a good safety profile in their series of 87 patients undergoing RA thyroidectomy.
The second surgical access to the thyroid bed begins in the midline using the bilateral axillobreast (BABA) technique. This approach offers the surgeon the same midline approach as open thyroidectomy. The main benefit of remote access thyroidectomy is that it leaves no scar on the neck, which is obviously important to some patients. The robotic system also provides the surgeon with a magnified, three-dimensional view of the surgical field which enhances the ability to preserve the RLN, external branch of the superior laryngeal nerve (EBSLN), and the parathyroid glands. In this chapter, we describe the robotic thyroidectomy performed via the lateral approach from either the TA or RA incision.
Key Operating Learning Points
- 1.
It is essential to gain exposure and create a wide working space before proceeding to the console to perform robotic thyroidectomy.
- 2.
Make sure that the robotic working arms are docked between 30 and 45 degrees to the camera arm so as to increase the maneuverability of both working instruments.
- 3.
Identify the omohyoid muscle first before proceeding to mobilize the thyroid gland; this is important in preventing inadvertent injury to the internal jugular vein (IJV).
- 4.
Owing to the lack of haptic feedback to the console surgeon, proper identification of the trachea and cervical esophagus is crucial in avoiding accidental injury to these structures.
- 5.
It is important to ensure a near bloodless field when the RLN is dissected at Berry’s ligament to prevent inadvertent injury to the nerve and postoperative hematoma.
- 6.
Monitoring of the RLN is helpful to confirm both anatomic and functional preservation of the nerve during surgery and upon completion of the thyroidectomy.
Preoperative Period
History
- 1.
Previous thyroidectomy or other neck surgery
- 2.
Thyroid status (e.g., hypothyroid or thyrotoxic)
- 3.
History of neck or shoulder problems
- 4.
History of keloid or hypertrophied scar
Physical Examination
- 1.
Body mass index (BMI)
- 2.
Size of thyroid nodule, unilateral or bilateral nodules
- 3.
Range of motion of cervical spine and shoulder
- 4.
Direct laryngoscopy before surgery to evaluate vocal cord function
Imaging
Thyroid Ultrasound
Because of the operator-dependent nature of this modality, thyroid ultrasound is best performed by a physician specializing in thyroid imaging. The overall size of the gland, number of thyroid nodules, and any features raising suspicion of malignancy (e.g., taller than wide, hypoechoic nodule, peripheral vascularization, microcalcifications, irregular margins) should be documented. The presence of enlarged and suspicious lymph nodes in the central compartment should also be noted.
Fine-Needle Aspiration Biopsy
Fine-needle aspiration biopsy (FNAB) is helpful for categorizing nodules according to risk of malignancy. At both our institutions, the Bestheda classification system is adopted. Additionally, we perform molecular markers (using a panel of common mutation markers) to help further risk-stratify nodules categorized as indeterminate (e.g., follicular lesion of undetermined significance (FLUS), follicular neoplasm, suspicious for malignancy). Using this panel of markers, preoperative counseling for upfront total thyroidectomy, rather than a diagnostic thyroid lobectomy, can be achieved in order to avoid completion thyroidectomy as a second-stage procedure.
Thyroid Scan
This is seldom performed unless there is clinical suspicion of a hyperfunctioning solitary thyroid nodule that could account for a thyrotoxic state. In this instance, the scan will demonstrate a solitary “hot” thyroid nodule, and surgery to remove this nodule would be indicated to restore a euthyroid state.
Indications for Robotic Thyroidectomy
- 1.
Thyroid nodule smaller than 5 cm
- 2.
BMI less than 35
- 3.
No prior neck surgery
- 4.
Small T1–T2 thyroid cancer (well-differentiated variant papillary thyroid cancer or follicular cancer)
Contraindications
- 1.
Graves disease
- 2.
Substernal extension of the gland
- 3.
Locally advanced thyroid cancer with invasion of the RLN/tracheoesophageal complex/strap muscles
- 4.
Known central compartment or lateral cervical lymph node metastasis
- 5.
Medullary thyroid cancer
Relative Contraindications
- 1.
Thyroid pathologies that require primary total thyroidectomy (e.g., multinodular goiter with sizable nodules on both thyroid lobes, thyroid cancer)
- 2.
Suspicion for central compartment lymph node metastasis in patients with thyroid cancer
Preoperative Preparation
The choice of the surgical approach should be discussed preoperatively with the patient. We have no specific preference in the choice of surgical access, although an RA approach is associated with a shorter dissection distance to the thyroid bed, and this access is also more intuitive for head and neck surgeons. Nevertheless, in the TA approach, up to three operating robotic arms may be deployed, which can facilitate the retraction of tissue by the third operating arm. This third arm may be inserted directly from the TA incision or via another 5- to 8-mm periareolar incision. However, in our experience with the RA approach, the deployment of the third operating arm through this incision often makes it collide with the working arms, since operating arms of the da Vinci Si system are bulky. A comparison of these two approaches is summarized in Table 80.1 .
| Retroauricular Approach | Transaxillary Approach | |
|---|---|---|
| Elevation of the cervical flap | Shorter distance to thyroid bed | Longer distance to thyroid bed |
| Identification of the superior thyroid pedicle/EBSNL | Excellent | Good |
| Identification of the recurrent laryngeal nerve | Excellent | Excellent |
| Concurrent central compartment neck dissection | Excellent | Good |
| Brachial nerve neuropathy | No | Rare (2%) |
| Maximum number of deployable operating robotic arms in the da Vinci Si system | Two | Three |
Operative Period
Anesthesia
The patient is placed in the supine position, and an orotracheal tube (a laryngeal monitoring tube) is inserted for intraoperative monitoring of the RLN. The orotracheal tube is placed to the side opposite the site of thyroidectomy, and the airway circuit is brought down toward the patient’s feet.
Position
In the TA approach, the upper arm is extended with the elbow flexed and internally rotated so as to expose the entire axilla without undue tension on the brachial plexus ( Fig. 80.1 ). It is critical to make sure that the bony pressure points of the upper limb are adequately protected with soft cotton padding so as to prevent skin necrosis. Because of the remote risk of traction brachial plexopathy with prolonged shoulder extension, some surgeons have adopted additional intraoperative monitoring for both the radial and ulnar nerves. However, we have not found this to be necessary as the key to prevention lies in avoiding undue tension on the brachial plexus with the modified position of the upper limb. In the RA approach, both arms are tucked alongside the body in neutral position, and the head is turned away from the site of operation. We do not use a shoulder roll for neck extension in either of these approaches.
Perioperative Antibiotic Prophylaxis
A thorough cleaning of the surgical field with Betadine iodine is adequate, and no perioperative antibiotic is necessary.
Instruments and Equipment to Have Available
At both our institutions, robotic thyroidectomy is performed using the da Vinci Si robotic system. We use the 10-mm 30-degree camera, which is positioned downward in order to visualize the entire surgical field. The two robotic working arms are the harmonic shears (8 mm) and the Maryland grasper (5 mm). An atraumatic Prograsp (8 mm) may be used instead of the Maryland grasper.
The assistant surgeon is stationed at the patient’s side and assists the console surgeon in the following ways:
- 1.
Providing countertraction during dissection
- 2.
Retraction of the sternocleidomastoid muscle (in the RA approach)
- 3.
Hemostasis using a fine long-tip bipolar cautery
- 4.
Suctioning of the smoke fumes during surgery
- 5.
Ensuring that the working arms are functioning at an optimal position without collision
The equipment that is essential to perform these functions is as follows:
- 1.
Long-tip monopolar and bipolar cauteries
- 2.
Lighted retractor system during flap elevation
- 3.
Headlight
- 4.
“Chung” retractor system
- 5.
Rolled cotton pledgets
- 6.
Yankauer suction
Key Anatomic Landmarks
- 1.
Omohyoid muscle
- 2.
Trachea
- 3.
Cricothyroid muscle
- 4.
Inferior thyroid artery (ITA)
Prerequisite Skills
Before embarking on robotic thyroidectomy, the surgeon must have sufficient experience in performing open thyroidectomy. A prior experience in endoscopic surgery was not identified as a significant requirement among fellowship-trained surgeons embarking on robotic thyroidectomy. The console surgeon should be familiar with the setup and functions of the da Vinci robot. This can be accomplished through either structured credentialing courses (offered by Intuitive Surgical Inc.) or through a comprehensive head and neck fellowship program including a large volume of robotic surgery. Additionally, both dry and wet laboratory training are helpful in shortening the learning curves involved. In the dry laboratory, computer-simulated programs mimicking several surgical situations can increase the surgeon’s skills in accomplishing the tasks required by robotic surgery. Similarly, wet laboratory cadaveric training with hands-on operative experience is invaluable in enhancing the learning experience. We recommend that the beginning surgeon perform the first five cases under supervised proctorship by an experienced surgeon in order to gain confidence with this new technique.
Operative Risks
In addition to the specific risks to the RLN and EBSLN, robotic thyroidectomy carries with it several potentially serious complications that are not usually encountered in standard open thyroidectomy. Perforation of the trachea and vascular injuries have been reported, which may be related to the lack of haptic feedback afforded to the console surgeon. However, a good understanding of the surgical anatomy and keeping the surgical field bloodless will help to minimize these complications. In the TA approach, excessive and prolonged traction on the shoulder may result in brachial plexopathy. With our modified positioning of the upper limb, we have not encountered this complication. Injuries to vascular structures such as the carotid artery or IJV may occur during dissection, especially if the dissection is performed in a rough manner. In the event of an injury to the carotid artery, direct external pressure to the carotid artery should be applied while the surgeon opens the neck in the conventional manner to expose the carotid sheath. As for injury to the IJV, bleeding from minor lacerations may be stopped with bipolar cautery or hemostatic surgical clips. In the instance of a major injury to the IJV, this vein may have to be sacrificed in order to gain complete hemostasis.
In patients who develop delayed postoperative hemorrhage or hematoma, securing hemostasis under general anesthesia is performed through the same remote access incision and without using the da Vinci robot. In this situation, a 10-mm endoscope (both 0 and 30 degrees) will help the surgeon to stop the bleeding points with either bipolar cautery or harmonic shears.
Surgical Technique
The surgical techniques of robotic thyroidectomy can be divided into the following categories.
Creating the Working Space
The creation of an adequate working space over the thyroid bed is critical to gain unrestricted maneuverability of the robotic instruments. This part of the operation is performed under direct vision using a long-tip monopolar cautery and a headlight for adequate illumination of the surgical field. A lighted retractor system is progressively deployed once the skin flap has been raised approximately 5 cm from the incision. A Yaukeur suction is used to aspirate the smoke and provide countertraction during the dissection. The typical length of the skin flap raised for the TA and RA approaches is between 12 to 14 cm and 10 to 12 cm from the incision, respectively.
In the TA approach, a 4- to 5-cm incision is placed 5 to 8 mm posterior to the anterior axillary fold in order to conceal the scar posterior to the skin fold. A skin flap is elevated over the pectoralis major muscle until the clavicle is encountered. Beyond this point, the skin flap is elevated in a subplatsymal fashion. The skin flap is elevated over the clavicular and sternal attachments of the sternocleidomastoid muscle until the level of the thyroid cartilage and just beyond the midline of the neck. Care must be taken to identify the omohyoid muscle and avoid getting deep to this muscle, since the carotid sheath and the IJV lie deep and medial to this plane.
In the RA approach, a 4- to 5-cm incision is placed approximately 5 to 8 mm posterior to the hairline in order to conceal the incision ( Fig. 80.2 ). The flap is raised in the direction of the suprasternal notch, and this plane is also approximately the axis where the retractor blade will be positioned to retract the flap. First, the line of incision is infiltrated with xylocaine with adrenaline (1:80,000). A subplatysmal skin flap is elevated over the sternocleidomastoid muscle, taking care to preserve the greater auricular nerve and external jugular vein. The skin flap is elevated medially over the strap muscles beyond the midline raphe and as far superior as the clavicle at the inferior limit. The flap is elevated over the tail of the parotid and up to the ramus of the mandible. Care must be exercised to avoid injuring the marginal mandibular nerve.
