40 - Hauptsitzung
16. Mai 2019, 08:30 - 10:15, Bellavista 5, 6. OG
Assessment of intraoperative parathormone monitoring (IOPTH) during minimal invasive parathyroid surgery
C. Urena, T. Zingg, N. Demartines, M. Matter, Presenter: C. Urena (Lausanne)
Hyperparathyroidism (PHP) is due to single adenoma in more than 80% of patients. Best treatment is minimal invasive parathyroid surgery (MIP) today possible because of the value of Imaging (MIBI scintigraphy with SPECT-CT or PET-choline). In order to overcome a missed double adenoma, guidelines recommend using intraoperative PTH monitoring (IOPTH). Based on decreasing PTH values (or not) in defined periods, surgeons must continue exploration. IOPTH strategy however, was challenged due to waiting time and costs.
Single tertiary center assessment of 377 patients operated for PHP by MIP between 2005 and 2018. MIP and IOPTH were feasible in 217 patients based on MIBI scintigraphy. IOPTH were performed at T0 (induction), T 10 min, and T 15 min. after adenoma clamping. Patients were divided in group A and B according to a successful IOPTH monitoring (50% T0 PTH decrease in 10-15 min A) or not (B). Based on the high accuracy of imaging and to avoid waiting time the meaning of unsuccessful IOPTH was challenged in our institution, and did no longer indicate further surgery. PTH dosage was then performed at day 1 only. Statistics used in the present study were Student T test and Chi-square test.
In group A one successfully operated patient out of 185 (0.5%9 had a persistent PHP with a second adenoma removed 9 months later). Only one single patient had double adenoma detected preoperatively and treated successfully. In group B only one patient out of 32 was further explored (3%): no second adenoma was detected and PTH returned to normal value. Only one single patient not further explored remained with PHP. In the remaining 30 patients 22 had a normal PTH at day 1 and 8 during the next days. Specificity of IOPTH was 0.86 and sensitivity 0.5. Patients in group A were significantly younger with significantly lower preoperative and T0 PTH (p<0,05). No difference was observed regarding gender distribution and position of adenomas (P3 versus P4).
Double adenoma is a rare event. Based on high false negative rate of IOPTH and because of better imaging (PET-choline) IOPTH should not be used systematically in MIP.