Robotic and Extracervical Approaches to the Thyroid and Parathyroid Glands: A Modern Classification Scheme

Chapter 36 Robotic and Extracervical Approaches to the Thyroid and Parathyroid Glands


A Modern Classification Scheme




Introduction


imagePlease go to expertconsult.com to view related videos Robotic Thyroidectomy: Left Thyroid Lobectomy via a Single Axillary Incision and Robotic Postauricular Thyroid Approach.


Minimally invasive surgical techniques1 have transformed surgical practice over the past two decades, beginning with arrival of laparoscopic cholecystectomy2 and the first randomized prospective trial in surgery comparing open versus laparoscopic colectomy.3 While significantly reducing incision length, pain, and morbidity associated with the traditional surgical approaches, in many cases minimally invasive techniques have been shown prospectively to achieve the same surgical objective. Thus, these techniques have supplanted many “open” procedures in the abdomen, pelvis, and chest. The adoption of minimally invasive techniques for thyroid, parathyroid glands, and neck has proceeded at a much slower pace.


The rising incidence of thyroid cancer and patient-driven demand has accelerated the evolution of endoscopic neck surgery. Davies and Welch reviewed the Surveillance, Epidemiology, and End Results (SEER) database on thyroid cancer mortality from the National Vital Statistics System from 1973 to 2002 and found that the incidence of thyroid cancer rose from 3.6 per 100,000 in 1973 to 8.7 per 100,000 in 2002, representing more than a twofold (p < 0.001) increase.4 Most of this increase was related to an increase in new cases of papillary thyroid cancer, which rose from 2.7 to 7.7 per 100,000, almost a threefold increase of this decade (p < 0.001). However, although the incidence of well-differentiated thyroid cancer increased, overall mortality did not change between 1973 and 2002, remaining at an estimated 0.5 deaths per 100,000. These authors suggested that this rise was the result of improved detection of occult small cancers rather than an increase in the true occurrence of clinically significant thyroid cancer. Chen and colleagues reviewed the same National Cancer Institute-SEER database from 1988 to 2005 and found that the rate of all well-differentiated thyroid cancer (WDTC) rose over this time period in both women and men.5 In this more recent cohort, the incidence of WDTC increased across all stages, suggesting that increased diagnostic scrutiny alone does not explain his trend. Elisei et al. found a similar trend in Europe.6 Certainly more patients, most of them female, are having thyroid surgery in the 21st century. As a result, and especially in light of the favorable prognosis for differentiated thyroid cancer, surgeons are finding new approaches to an old problem. Many surgical innovations rely on an extracervical approach to the thyroid and parathyroid glands, minimizing visible scars (see Chapter 42, Incisions in Thyroid and Parathyroid Surgery). Some are minimally invasive; all are endoscopic.


As technology improves, surgeons are reexamining traditional surgical approaches and developing innovative endoscopic approaches that potentially may offer significant benefits (see Chapter 43, Technological Innovations in Thyroid and Parathyroid Surgery). Traditional thyroid surgery, described by Kocher in the 1880s, has undergone incremental improvements over the years related to enhancements in anesthesia, understanding of the anatomy, and surgical technology (see Chapters 30, Principles in Thyroid Surgery, 31, Minimally Invasive Video-Assisted Thyroidectomy, and 61, Minimally Invasive Video-Assisted Parathyroidectomy). Improved visualization and instrumentation offer the potential to alter surgical approaches to the thyroid and parathyroid. Although innovation can be exciting, it is important that it occurs in a rational fashion and with consideration of the goals of the thyroid surgery. Costs and benefits from multiple perspectives, including patients, surgeons, the health care system, and even society, must also be considered. Innovation is fluid, learning curves do exist, and patients may be at risk during this process.



Goals of Endoscopic Thyroid Surgery


When assessing any surgical technology it is important to consider the goals of the procedure. There may be trade-offs. Accomplishing one goal may occur at the expense of another, so it is important to prioritize surgical goals. Parameters should be set for acceptable outcomes so that potential limitations and trade-offs can be evaluated. Furthermore, the current standard method (traditional open thyroidectomy) should be used as a baseline for comparison in order to evaluate for improvement.


With respect to thyroid surgery, there are three major goals. Of these goals, clearly the most important priority is to efficaciously treat the disease process. There may be some debate about the relative priority of the other two goals, and even a difference of opinion between physicians and their patients.




Goal 2: To Minimize Long-Term Side Effects of Surgery and to Reduce Complications


In some cases, the long-term effects of surgery may be considered complications, whereas surgeons may currently accept others as normal sequelae of surgery. The long-term implications and changes that occur may ultimately be of great concern. As examples, the need for thyroid replacement in the case of lobectomy, voice changes as an effect of permanent nerve injury, and cervical scarring may potentially have long-standing implications for affected patients, depending on their perceptions. For some patients these may be serious concerns, whereas others may not perceive a problem exists. Although preoperative informed consent and patient education can be helpful in setting appropriate expectations, innovations that reduce the long-term implications are desirable for patients.


The type and rate of complications for traditional thyroidectomy are well described in the literature (see Chapters 33, Surgical Anatomy and Monitoring of the Recurrent Laryngeal Nerve, and 47, Non-Neural Complications of Thyroid and Parathyroid Surgery). When new techniques are completely developed, it is important that complication types and rates are evaluated relative to rates for traditional thyroidectomy. New techniques also may result in new complications that do not occur with traditional approaches. These new complications need to be carefully evaluated and considered.


When comparing the complications from new techniques, it is important to consider the learning curve and surgeon experience. There may be risks related to the learning curve itself. If these risks cannot be eliminated through training, then the morbidity and its costs associated with these complications must be considered in the introduction of the technique and reduced wherever possible.





Recent Surgical Innovation


Surgical innovation may occur by applying new technology to a procedure or with new anatomic approaches to accomplish existing surgical goals. Sometimes these innovations may be incremental; in other instances the new technique may be completely unrecognizable from traditional “open” surgery. Several advances in technology have been applied to thyroid surgery, each with potential benefits.



Visualization Technology


Since the 1990s, significant technical improvements facilitating visualization, both in the areas of lighting and magnification, have been realized. The intensity of available light both for fixed room lighting and headlights has increased. Retractors with a built-in light source can place light directly into the surgical field, thereby improving visualization.


Magnification is another aspect of surgical visualization. Whereas many surgeons perform thyroid surgery using direct visualization, the application of surgical loupes for open procedures significantly improves visualization by magnifying critical structures.


The application of endoscopic telescopes with a camera system, such as used in video-assisted thyroidectomy, combines magnification and superior illumination to provide an excellent two-dimensional view. The lack of three-dimensional visualization alters the ability to accurately judge the depth of structures and is associated with a learning curve. Physical rotation of the endoscopes and the use of angled endoscopes provide the benefit of visualizing locations that cannot normally be accessed by direct line of sight. Current telescope technology allows for high-definition images and digital magnification. The use of these telescopes requires the operating surgeon to only use one hand to operate, use a mechanical scope holder to fix the location of the scope, or have a skilled assistant hold the scope in place during surgery.


Stereoscopic visualization enhances visualization further by utilizing two endoscopes that collect images from slightly different angles, providing magnified three-dimensional images. True stereoscopic systems require computerized image integration and display in a specialized immersive environment. The immersive environment may be created by the use of LED glasses and a special display, a head-mounted display, or via a fixed console, allowing the surgeon to be “immersed” in the images. Three-dimensional images are vastly superior to two-dimensional images in that depth perception is restored. Angled endoscopes are also available with this technology.






Classification of Surgical Techniques


Since the 1990s there has been a proliferation of new surgical techniques for endoscopic surgery of the thyroid and parathyroid glands. Although many have been deemed “feasible” by publication, few of these techniques are widely practiced beyond the developing institution, with the exception of video-assisted thyroidectomy and parathyroidectomy as described by Miccoli79 and Bellantone10 (see Chapters 31, Minimally Invasive Video-Assisted Thyroidectomy, and 61, Minimally Invasive Video-Assisted Parathyroidectomy) and, more recently, robotic thyroidectomy via a gasless, transaxillary approach, as described by Chung11 (see Box 36-1 for a detailed description of this technique). Table 36-2 compares these approaches.


Table 36-1 Classification Factors for Thyroid Surgery








Box 36-1 Robotic Thyroidectomy: Chung’s Transaxillary Gasless Technique4,33,34





Robot Docking


The da Vinci Surgical System is then moved to a position that is adjacent to the table and the arms are oriented to insert the instruments. A 30-degree down stereoscopic endoscope camera is placed in the center and should be angled to be low outside of the wound and high inside the wound. Then a 5-mm Harmonic curved shears and a 5-mm Maryland dissector are placed in the axillary port. In a single-incision approach,34,62 the ProGrasp forceps are placed inferior to the camera, superior to the other inferiorly placed instrument. The Harmonic curved shears are placed in the position that would correspond with the surgeon’s dominant hand. The instruments should be placed so as to enter high in the wound and be angled to a low position, so that they are under the camera.



Table 36-2 Comparison of Commonly Performed Approaches















Approach Advantages Disadvantages
Traditional thyroid surgery
 (type I, gasless, manual)


Small incision
 (type I, gasless, endoscopic, manual)


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Jul 23, 2016 | Posted by in OTOLARYNGOLOGY | Comments Off on Robotic and Extracervical Approaches to the Thyroid and Parathyroid Glands: A Modern Classification Scheme

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