Keywords

These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Background

Due to particular cultural attitudes and a predilection for hypertrophic scarring, avoidance of cervical incisions has been particularly sought after in Asia. Initially, remote access endoscopic procedures were utilized. These tended to be technically challenging and protracted procedures.

Over the last several years, Woong Youn Chung and his colleagues have advanced remote access thyroid surgery with two critical innovations. The first was introduction of a fixed retractor system, which eliminated the need for gas insufflation to maintain the operative pocket. Following this, Dr. Chung further enhanced the field by introducing the use of the surgical robot into his robot-assisted, gasless transaxillary thyroidectomy technique (RAT). The robot’s ability to perform delicate maneuvers in constrained spaces is ideally suited for the restricted operative pocket created in RAT and other remote access techniques. This group of surgeons has now demonstrated that these procedures could be done in a high-volume, safe, and efficient manner in a Korean population. This operation generated tremendous enthusiasm in other parts of Asia, and eventually in North America.

However, the introduction of RAT in the United States was accompanied by a number of significant complications, including brachial plexus injury, large volume blood loss, and persistent pain. It became clear that performance of the transaxillary thyroidectomy technique in American patients posed significant challenges. Many surgeons have suggested that the difficulties lie in the substantial differences in body habitus and morphology that exist between American and Korean patients. American patients are typically heavier and taller, with larger necks. In addition to patient differences, the size and type of disease encountered in the United States versus Korea is another possible obstacle to smooth implementation of RAT in the United States. Many of the nodules and cancers operated on in Korea represent disease which would not even be likely biopsied in the United States.

In an effort to overcome these barriers and to develop a remote access technique that is less challenging and easier to learn, RFT was conceptualized. Development of RFT benefitted from several factors. All previous remote access techniques were designed as endoscopic procedures and only later was use of the robot incorporated into them. RFT was the first remote access technique conceived with use of the robot in mind, so that the surgery was designed to optimize its abilities. Additionally, RFT was implemented with lessons drawn from the development and evolution of other remote access techniques. RFT consequently is a hybrid approach, which integrates important components of traditional thyroid surgery with several innovative principles. These include use of the modified facelift incision, the integration of the da Vinci robot (Intuitive Surgical Inc., Sunnyvale, CA), and the use of a fixed retractor system as described by Chung.

The rational development of RFT imparts it with several potential advantages over other remote acess techniques. The modified facelift incision, the value of which is demonstrated by its widespread adoption in parotid surgery, results in a completely concealed incision after surgery. Additionally, this incision requires significantly less tissue dissection to approach the thyroid compartment compared to RAT. Furthermore, this dissection occurs along the anterior aspect of the sternocleidomastoid muscle and adjacent structures, surgical planes that are more familiar to many head and neck surgeons. This is likely partially responsible for the faster learning curve associated with RFT. Avoiding the need for special positioning of the arm, as is used in RAT, eliminates the possibility of brachial plexus injury (Fig. 10.1). Finally, as RFT does not require placement of a drain and can be performed as an outpatient procedure, fewer of the tremendous benefits achieved with “minimally invasive” thyroidectomy techniques have to be surrendered.

Fig. 10.1
figure 1

Positioning of the patient for RFT is straightforward. While lying supine on the operating table, the head is turned 30° away from the side of surgery. A cushion is then used to prevent excessive rotation of the head

Full size image

Selection Criteria

As with all surgical procedures, careful patient selection is fundamental for successful outcomes with RFT. Both disease and patient characteristics determine eligibility for the procedure.

Patients with presumed benign disease, with nodules not exceeding 4 cm in greatest dimension and with no substernal extension, are candidates for RFT. In order to ease the dissection during the procedure, the absence of thyroiditis is preferred. At this time, RFT should be limited to unilateral surgery. Due to anatomical constraints and the current state of robotic technology, visualization and dissection of the contralateral recurrent laryngeal nerve cannot be adequately achieved in order to perform a true total thyroidectomy.

Patient criteria must also be considered when assessing suitability for RFT. Patients should not be morbidly obese. Additionally, patients should be sufficiently healthy to tolerate a longer anesthetic exposure than is required for conventional thyroid surgery. Perhaps the most important factor is that the patient should be motivated to completely eliminate a neck scar, as this represents the principal advantage of remote access surgery. The patient should be fully informed of the risks of the procedure, including the expectation of hypesthesia in the region of the greater auricular nerve.

Procedural Details

Preoperative

Safe and successful performance of RFT requires contributions from the entire surgical team—nurses, anesthesiologists, and surgeons. All members of the robotic team should be well versed in the principle steps of the procedure. This will ensure efficiency of the operation.

The anesthesiologist should use circuit extenders to facilitate a 180° turn of the operative table. Laryngeal nerve monitoring is typically utilized, and intubation using a video laryngoscope device helps to ensure proper positioning of the laryngeal electromyographic endotracheal tube. Given the nerve monitoring, paralytic agents should be avoided.

Preoperatively, the surgeon should mark the incision both for RFT and for a cervical approach (Fig. 10.2). This would be used only in the rare case in which conversion to an open approach is needed. Both of these marks should be placed with the patient in the upright position in the holding area, in order to identify the most cosmetically pleasing sites. The postauricular incision begins just behind the ear lobule and runs in the postauricular crease. It crosses into the occipital hairline at a point above where the incision will be hidden by the auricle, and then extends down within the occipital hairline (this hair is clipped after intubation and positioning).

Fig. 10.2
figure 2

The incision is placed in the postauricular crease and then crosses into the occipital hairline

Full size image

Intraoperative

One of the benefits of RFT is that positioning of the patient is straightforward. The patient is placed on the operating table in the supine position. After intubation, the endotracheal tube is secured in position and the table is turned 180° away from the anesthesia cart. The patient’s head is turned 30° away from the side of the surgery. In order to prevent excessive rotation of the neck during the procedure, a cushion is placed next to the head on the side contralateral to the side of surgery. No urinary catheter is needed.

Approximately 1 cm of hair is clipped along the descending limb of the incision. Quarter percent bupivacaine with 1:200,000 of epinephrine is then injected along the length of the incision. After sterile prepping and draping, the table is placed in reverse Trendelenburg position and airplaned away from the side of surgery to improve ergonomics for the operative surgeon.

After the incision is made, dissection is performed down to the level of the sternocleidomastoid muscle. Flap elevation is achieved first in the subcutaneous and then the subplatysmal plane. Particularly in thinner patients with less subcutaneous fat, care must be taken to avoid creating a buttonhole through the flap and skin. After identifying the sternocleidomastoid muscle, the great auricular nerve and then the external jugular vein are encountered. Dissection should be maintained ventral to these structures. The entire length of the sternocleidomastoid muscle is then exposed, with particular attention paid to releasing the anterior border of the muscle.

Identification of the omohyoid muscle is the next critical step. By dissecting and then retracting this muscle ventrally, the sternohyoid and sternothyroid muscles are exposed (Fig. 10.3). These muscles are then reflected from lateral to medial, exposing the upper pole of the thyroid gland.

Fig. 10.3
figure 3

A view of a right-sided operative pocket, with critical landmarks highlighted. The great auricular nerve (GAN), external jugular vein (EJV), sternocleidomastoid muscle (SCM), and the omohyoid muscle are indicated

Full size image

The omohyoid muscle is most readily seen by rolling the anterior border of the sternocleidomastoid muscle laterally, a maneuver performed well with a malleable retractor. Cadaver dissections and intraoperative assessments have revealed that the omohyoid muscle can be consistently identified just inferior to an axial line drawn through the inferior aspect of the thyroid notch (Singer MC, 2012). The sternohyoid and sternothyroid muscles are elevated off the underlying thyroid gland down to the level of the sternum and then retracted ventrally with a modified version of the Chung retractor blade (Marina Medical, Sunrise, Florida) (Fig. 10.4). This maintains the operative pocket. Additional exposure is achieved by retracting the sternocleidomastoid muscle laterally using a retractor fixed to the operating table.

Fig. 10.4
figure 4

After the strap muscles are elevated off of the underlying thyroid gland, the superior pole of the gland is well visualized (Reprinted with permission from Terris DJ, Singer MC, Seybt MW. Robotic facelift thyroidectomy: II. Clinical feasibility and safety. Laryngoscope. 2011;121(8):1636–41)

Full size image

After the retractors are positioned, the da Vinci surgical robot is deployed. The pedestal of the patient side cart is positioned on the side contralateral to the surgery, with the arms extended parallel to the long axis of the fixed retractor. Three arms are utilized: the camera arm is positioned first, holding a 30° down endoscope parallel to the retractor system, or angled slightly upward. A Maryland grasper is placed in the nondominant arm, and a Harmonic device (Ethicon Endo-Surgery Inc., Cincinnati, Ohio) is placed in the dominant arm. These are positioned on either side of the endoscope. In order to minimize collisions of the robotic arms, the working arms should be angled in such a way that they create a “V” in the axial plane.

For excision of the gland, the operative surgeon is seated at the robotic console. A bedside assistant supports performance of the surgery by suctioning and retracting as necessary. At this point, the upper pedicle of the gland, exposed during the open phase of the case, is further mobilized. Once isolated the pedicle is ligated in a single bundle using the Harmonic device. The superior aspect of the thyroid lobe is then reflected inferiorly, exposing the inferior constrictor muscle. Frequently, the superior parathyroid gland is visualized in this area. This gland is preserved by dissecting it posterolaterally (Fig. 10.5). Medially, the superior laryngeal nerve can be observed running on the inferior constrictor muscle. At this point, the recurrent laryngeal nerve is sought and clearly delineated. Using blunt dissection to demarcate the inferior border of the inferior constrictor muscle, the nerve can be recognized laterally, just prior to its entry deep to the muscle. Often the origin of the inferior constrictor muscle from the cricoid cartilage can be visualized. If observed, this oblique line can be used as a landmark for identifying the recurrent nerve, as the entry point of the nerve is approximately 1 cm lateral to this line. After initial recognition the recurrent nerve is dissected inferiorly for a short distance (Fig. 10.6). To confirm proper function of the nerve monitoring system, the recurrent nerve can be stimulated at this time. As the nerve is now exposed laterally, the tissue medial to this, including the ligament of Berry, may be safely divided using the Harmonic device. The thyroid isthmus is then divided and the middle thyroid vein ligated. Attention is then turned to the inferior aspect of the gland. The inferior parathyroid gland is mobilized with its blood supply intact and released. The remaining attachments inferiorly, including the inferior thyroid artery and vein, are then transected. Final attachments of the gland to the trachea are lysed, completing release of the lobe. The specimen can now be delivered through the wound. The surgeon can elect to stimulate the recurrent nerve a final time at this point. The robotic arms and patient cart are then withdrawn.

Fig. 10.5
figure 5

After the superior pedicle is ligated, the superior parathyroid gland (white arrow) can often be identified on the posterior aspect of the thyroid gland. Releasing it posteriorly preserves the parathyroid gland

Full size image
Fig. 10.6
figure 6

The recurrent laryngeal nerve (white arrow) is sought just inferior to its entry deep to the inferior constrictor muscle, its most constant location. Here, a right-sided nerve is seen after dissection

Full size image

Following irrigation, the operative bed should be examined for the presence of any bleeding. Typically, bleeding is minimal but absolute hemostasis should be assured. Surgicel (Ethicon Inc., Somerville, New Jersey) is placed in the wound and the subcutaneous tissues are closed with interrupted sutures of 4-0 Vicryl. The incision is then closed as per the surgeon’s preference (cyanoacrylate glue is used in our practice, with an overlying dressing). No drain is placed. A deep extubation, which may help prevent oozing, is recommended.

Postoperative

Patients are managed on an outpatient basis. They are observed in the recovery room and discharged home as per the hospital’s routine.

Patients are prescribed antiemetic and pain medications. They are instructed to limit activities for 14 days postoperatively. As per routine, patients who have undergone bilateral or completion surgery are prescribed a 3-week course of oral calcium supplementation beginning on the evening of surgery and are counseled regarding the signs and symptoms of hypocalcemia.

Outcomes

Clinical outcomes have been excellent. Risk of permanent recurrent nerve injury or hypocalcemia is low. Due to dissection during development of the operative pocket, patients do experience hyperesthesia in the distribution of great auricular nerve. This resolves over the course of several months. However, patients should be alerted preoperatively to the possibility of this periauricular discomfort, in addition to other complications that are the same as with traditional thyroid surgery. As the postauricular wound is completely hidden (particularly in women with longer hair), cosmetic results are superb (Fig. 10.7).

Fig. 10.7
figure 7

Frontal view of patient 1 year after undergoing robotic facelift thyroidectomy (a). Note that from a frontal view, the scar is completely hidden. The resulting scar is shown (b)

Full size image

Future Directions

RFT is early in its clinical evolution. As noted earlier, due to anatomical and technological constraints, RFT currently should be limited to unilateral surgery. Improvements in robotic technology will likely in the near future allow for improved visualization and dissection of the contralateral thyroid compartment. These advances will allow for total thyroidectomy to be performed safely from a single incision. Additionally, the access obtained through the RFT incision exposes other critical anatomy and this approach could be used to perform other procedures. Surgeons have already begun to utilize this approach to perform lateral neck dissections. As experience with the RFT technique expands, the indications for the procedure will likely widen.