Minimally invasive parathyroidectomy using the 'focused' lateral approach. I. Results of the first 100 consecutive cases.

BACKGROUND: A feasibility study of 'focused' minimally invasive parathyroidectomy (MIP) using a lateral approach was commenced in 1999. The aim of the present paper was to evaluate the effectiveness and safety of this procedure in the first 100 consecutive patients.

METHODS: This was a prospective, non-randomized case-control study. One hundred consecutive patients with primary hyperparathyroidism (mean age 63.1 years; 74 females, 26 males) who fulfilled the inclusion criteria underwent focused MIP between May 1999 and December 2000. The results for the first and last 50 consecutive patients were compared to see whether they were reflective of a learning curve. The role of intraoperative quick parathyroid hormone (QPTH) estimation was also evaluated.

RESULTS: Focused MIP was successfully completed in 93 of 100 patients, with seven conversions. Three (3.2%) of the 93 patients had persistent hyperparathyroidism. Quick PTH was measured in 81 patients and the results were true positive (for cure) in 72 patients, false negative in six patients, true negative in two patients and false positive in one patient. Transient recurrent laryngeal nerve paresis occurred in one patient. During the same time period, open parathyroidectomy was performed in 242 patients. The results were not different between the first and later 50 patients undergoing MIP, nor were the outcomes significantly different from patients undergoing open parathyroidectomy.

CONCLUSIONS: Focused MIP is a safe and effective operative approach for appropriately selected patients. Failed procedures were invariably related to shortcomings of the localization studies. Measurement of QPTH, although accurate, is unreliable in the presence of multigland disease.