Technological Innovations in Thyroid and Parathyroid Surgery

Chapter 43 Technological Innovations in Thyroid and Parathyroid Surgery

Ultrasonic Energy (Harmonic)

One of the most significant advances in technology, which facilitates conventional surgery but also has allowed departures from traditional thyroid hemostatic approaches for both open and minimally invasive surgery, is the advent of the ultrasonic device (Harmonic ACE; Ethicon Endo-Surgery, Cincinnati, Ohio). The ultrasonic handpiece creates vibrations that occur at 55,500 times per second, which causes simultaneous cutting and vessel coagulation in the tissues contacted. It does so through denaturing cellular proteins, which then form a hemostatic seal.2 This technology is easily applied through small forceps on long extensions, making it an ideal tool for minimally invasive endoscopic and robotic surgery (Figure 43-1). The ultrasonic device has proved to be safe in thyroid surgery, contributing to reduced operating time, inpatient stays, and intraoperative and postoperative bleeding.3 Postoperative discomfort is also improved because there is less thermal injury to surrounding tissues, with no neuromuscular stimulation when compared to standard electrocautery devices.4,5 Hypocalcemia also appears to be reduced because of decreased thermal transmission to the parathyroid glands from the low-temperature ultrasonic energy.6

Electrothermal Bipolar Vessel Sealing System (LigaSure)

The combination of bipolar electrocautery and pressure allows less thermal energy utilization than traditional instrumentation. The LigaSure (Covidien, Boulder, Colorado) seals vessels up to 7 mm in diameter in an average of 2 to 4 seconds.8 Like the ultrasonic device, it may decrease surgical times, hospital stays, and hypocalcemia when compared to conventional thyroidectomy.912 A recent study compared the electrothermal bipolar, Harmonic device and traditional thyroid surgery and found surgical time to be equally reduced by use of either the electrothermal bipolar or the Harmonic. No difference was observed between these two modalities and conventional thyroidectomy in terms of nerve injury, bleeding, hypocalcemia, or hospital stay.13 Like the ultrasonic device, this instrument can be used for endoscopic or standard thyroidectomy approaches, so use of the instrument often depends on the surgeon’s preference and availability.

Laryngeal Nerve Monitoring

Although covered in considerable detail in other sections, it is appropriate to address laryngeal nerve monitoring here, particularly because it represents an important technological adjunct in modern thyroid surgery and is a natural complement to minimal access surgery (see Chapters 32, Surgical Anatomy of the Superior Laryngeal Nerve, and 33, Surgical Anatomy and Monitoring of the Recurrent Laryngeal Nerve).14

A number of reliable options for monitoring the integrity of the laryngeal nerves have emerged, with the device most commonly represented by an integrated electromyographic endotracheal tube (NIM 2.0, Medtronic Inc., Jacksonville, Florida). A lower-cost alternative is available in the form of surface electrode decals, which are affixed to a standard endotracheal tube (Neurosign and Nerveana), which requires the surgeon to adhere these correctly to the endotracheal tube (Figure 43-3). The principle is similar in each of these systems, in that electrodes detect electromyographic impulses from the thyroarytenoid muscles and relay them to the control unit, which presents them as an audible or visible signal. In some institutions, the monitoring is accomplished by a nonsurgical individual assigned to this task, or even a team of technicians (as is commonly done for multichannel neural monitoring systems as used for neurotologic or neurosurgical interventions).

This continuous passive monitoring process alerts the surgeon in the event of trauma to the recurrent laryngeal nerve (including stretching, clamping, or even gentle dissection), and the operating surgeon processes this information within the context of the overall conduct of the procedure and proximity to the laryngeal nerves. Another advantage is the potential for active stimulation of the recurrent laryngeal nerve or the external branch of the superior laryngeal nerve once identified or in the event or perceived trauma to confirm the physiologic integrity of the nerve in question. This maneuver is only rarely necessary, may have prognostic value, and is easily accomplished with an integrated stimulating electrode, which is long and slender and therefore lends itself to minimal access techniques.

Jul 23, 2016 | Posted by in OTOLARYNGOLOGY | Comments Off on Technological Innovations in Thyroid and Parathyroid Surgery

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