Minimally invasive video-assisted parathyroidectomy and intraoperative parathyroid hormone monitoring. The first 36 cases and some pitfalls

Background: The success of parathyroid surgery depends on the identification and removal of all hyperactive parathyroid tissue. At this writing, bilateral cervical exploration and identification of all parathyroid glands represent the operative standard for primary hyperparathyroidism (pHPT). However, improved preoperative localization techniques and the availability of intraoperative parathyroid hormone monitoring prepare the way for minimally invasive procedures. Methods: Patients with pHPT and one unequivocally enlarged parathyroid gland on preoperative ultrasound and 99mTc-SestaMIBI scintigraphy underwent minimally invasive video-assisted parathyroidectomy by an anterior approach. Intraoperatively, a rapid chemiluminescense immunoassay was used to measure intact parathyroid hormone (iPTH) levels shortly before and then 5, 10, and 15 min after excision of the adenoma. The operation was considered successful when more than a 50% decrease in preexcision iPTH levels was observed after 5 min. Results: Between October 1999 and November 2001, 36 of 82 patients with pHPT were eligible for a minimally invasive approach. A conversion to open surgery became necessary in five patients because of technical problems. In three cases, intraoperative iPTH monitoring showed no sufficient decrease in iPTH values. In these cases, subsequent cervical exploration showed one double adenoma and two hyperplasias, respectively. In two patients we had difficulty interpreting intraoperative iPTH values, resulting in persistent pHPT. Conclusions: Despite the use of high-resolution ultrasound and 99mTc-SestaMIBI scintigraphy, the presence of multiple glandular disease cannot be ruled out completely. Intraoperative iPTH monitoring to ensure operative success is indispensible for a minimally invasive approach. Despite our problems with iPTH monitoring in two patients, we believe that in selected cases, minimally invasive parathyroidectomy represents an attractive alternative to conventional surgery.