Patient Education and Consent
Elements of informed consent
The details of the procedure should be clearly explained, including the novel nature of the procedure and the consensus that open parathyroidectomy continues to be the gold standard. The risks of open parathyroidectomy should be reviewed, in that they are all relevant to transoral parathyroidectomy as well. These risks include, but are not limited to, the following:
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Scar formation and complications related to the incision
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Injury to the recurrent and superior laryngeal nerves
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Persistent or recurrent hyperparathyroidism
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Postoperative hypocalcemia
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Hematoma or seroma formation
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Damage to adjacent structures
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Need for further surgery
In addition to the risks associated with a standard approach to parathyroidectomy, the following risks that are specific to transoral parathyroidectomy should be discussed:
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Increased risk of infection as a consequence of the approach through the oral cavity
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Mental nerve injury with resultant lip or chin numbness
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Possible conversion to an open procedure with an anterior neck incision
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Injury to lips, gums, and teeth
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Subcutaneous emphysema
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Pneumomediastinum
Preprocedural Planning
Diagnosis of hyperparathyroidism and candidacy for surgery should be established and reviewed with the patient. As with any elective surgical procedure, medical conditions should be optimized, and anticoagulant medications should be withheld prior to surgery. Preoperative laboratory tests (especially parathyroid hormone [PTH] and serum calcium) should be ordered during the medical workup.
Preoperative parathyroid localization studies should be completed before the operation, with all imaging reviewed by and available to the surgeon. Use of intraoperative localization may also be considered (eg, by menas of rapid PTH or gamma probe).
See Parathyroidectomy for a review of the National Institutes of Health (NIH) guidelines for surgery in asymptomatic patients, as well as a detailed discussion of preoperative and intraoperative parathyroid location studies.
Equipment
The surgical equipment used in the procedure will depend to a large extent on the surgeon’s preference and comfort level. A key determinant is whether the transoral parathyroidectomy is to be performed endoscopically or robotically.
If the endoscopic approach is followed, one 10-mm trocar is used in the midline incision, and two 5-mm trocars are used, one in each of the two lateral incisions. Dissection involves a combination of hydrodissection with a Veress needle and blunt dissection with a dilator. An L-hook with monopolar cautery should be available, along with 30° 10-mm endoscopes and other standard endoscopic instrumentation. Surgical drains may be placed at the conclusion of the procedure, and supplies for a pressure dressing will be needed.
If the robotic approach is followed, the da Vinci robotic system (Intuitive Surgical, Sunnyvale, CA) and associated instruments will have to be available, along with the aforementioned supplies and equipment.
Patient Preparation
Anesthesia
General anesthesia should be used, with a nerve-monitoring endotracheal tube (eg, NIM TriVantage EMG Endotracheal Tube; Medtronic, Minneapolis, MN) taped near the oral commissure.
Positioning
The patient should be placed supine on the operating room table, with a shoulder roll positioned to allow slight neck extension. The arms should be tucked to the side so that the surgeon can stand on either side of the patient in the event that the transoral parathyroidectomy is converted to an open procedure. If intraoperative PTH levels are drawn, access to an intravascular site must be considered.
Monitoring & Follow-up
Intraoperative nerve monitoring of the vocal cords should be available throughout the procedure. Specific follow-up times are based on the individual surgeon's preference. Whatever the timing of follow-up, however, vocal cord function should be assessed on the first postoperative visit, and repeat laboratory tests should be obtained to rule out recurrent or persistent hyperparathyroidism.
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Approximate oral incision sites for placement of trocars
