Minimally Invasive Parathyroidectomy Using Cervical Block: Reasons for Conversion to General Anesthesia
Background: The indications for intraoperative conversion to general anesthesia (GA) were investigated in patients undergoing minimally invasive parathyroidectomy (MIP).
Material: Between January 2000 and April 2004, 441 consecutive patients with primary hyperparathyroidism (HPT) underwent MIP employing cervical block and monitored anesthesia care using midazolam and narcotics. Patients with known multiglandular, familial, or secondary HPT, or those electing MIP under GA were excluded. The superficial cervical block was administered on the ipsilateral side of the sestamibi-localized adenoma. In most patients, a total volume of 20 mL 1% lidocaine/1:100,000 epinephrine was used. Supplementation of local anesthesia and intravenous sedatives were used when required.
Results: Of the 441 patients, 47 (10.6 %) required conversion to GA. In all instances, conversion was performed in a controlled fashion using neuromuscular blockade, endotracheal intubation and maintenance of the original surgical field preparation. Sixteen procedures were converted to accomplish simultaneous thyroid resections. An additional 15 were converted because the intraoperative PTH level failed to decrease by at least 50% from the baseline after resection of the incident parathyroid tumor, and extensive exploration was required. Eight procedures were converted because of technical difficulties related to ensuring adequate protection of the recurrent laryngeal nerve. Five procedures were converted to optimize patient comfort, and two were converted due to the intraoperative recognition of parathyroid carcinoma. One patient experienced lidocaine toxicity, causing a seizure. Although transient inadvertent blockade of other nerves (e.g. vagus, brachial plexus) rarely occurred, there were no other complications of the cervical block.
Conclusion: The vast majority of MIPs can be performed using cervical block anesthesia. However, conversion to GA is appropriate when unexpected intraoperative findings are encountered or for patient comfort.
Back to Final Program