S. Zaheer1, L. Kuo1, H. Wachtel1, R. Roses1, G. Karakousis1, R. Kelz1, D. Fraker1 1Hospital Of The University Of Pennsylvania,Department Of Surgery,Philadelphia, PA, USA
Introduction:
Parathyroidectomy is a common surgical procedure. Currently, 10% of surgeons practice bilateral neck exploration(BNE), 68% use a minimally invasive approach(MIP), and 22% have a mixed practice. We sought to determine the reasons for failure of MIP as compared to failure of BNE.
Methods:
Patients with primary hyperparathyroidism who underwent reoperative surgery for recurrent or persistent disease were identified in our institutional prospective endocrine surgery registry(1997 to 2013) for the study. The primary outcome of interest was reason for failure of the initial surgery determined by intra-operative findings and pathologic review. Univariate analysis was performed to examine differences across reoperative patients who underwent BNE compared to those who underwent MIP as the initial procedure using the Chi-square test, as appropriate.
Results:
Of 141 patients who met study criteria, 28% (n=39) had undergone MIP and 72% (n=102) BNE. Patient characteristics including age, race, gender, body mass index, calcium, PTH level and symptoms were similar across the two groups. Recurrent disease was associated with abnormal glands in ectopic locations (n=45), adenomas in normal positions(n=33), hyperplasia(n=25), MEN-associated hyperplasia(n=21), parathyroid cancer(n=6), abnormal supernumerary glands(n=5), and parathymatosis (n=4). Reoperation failed to identify the cause of failure in 2 patients. A single parathyroid adenoma was the most common cause of operative failure following MIP. Adenoma in a normal location was more common following MIP than BNE (43.59% vs 15.09%, p=0.005). In BNE failures, ectopic gland was the most common cause. The frequency of failure due to ectopic gland was greater amongst BNE when compared to MIP(31 % vs. 7%, p=0.005). In initial MIP, IOPTH monitoring was used in 45% (n=17) of patients. Of these patients, 4 had intraoperative parathyroid hormone (IOPTH) levels which failed to normalize; 3 had incorrect interpretation of IOPTH.
Conclusion:
Failure following MIP is often due to a missed adenoma in a normal location as opposed to failure following BNE, which is often associated with a missed ectopic gland. All patients should be counseled on the possibility of an ectopic gland prior to parathyroid exploration. Experienced surgeons preferably skilled in the use of IOPTH monitoring should perform MIP to avoid unnecessary failure.