Impact of modern techniques on short-term outcome after surgery for primary hyperparathyroidism: a multicenter study comprising 2,708 patients

Minimally invasive surgery for primary hyperparathyroidism has become an accepted part of endocrine surgical practice worldwide. Survey of members of the International Association of Endocrine Surgeons. Clinical practice of endocrine surgeons worldwide. Numbers of parathyroid procedures performed, types of minimally invasive procedures undertaken, and techniques used to ensure completeness of removal of hyperfunctioning parathyroid tissue as reported by the survey respondents. Of 160 surveys completed, 95 (59%) indicate that the surgeons currently perform minimally invasive parathyroidectomy and use this technique on average for 44% of patients with primary hyperparathyroidism. The most common approach is the focused technique with a small incision, either central or lateral (92% [87 respondents]), followed by a video-assisted technique (22% [21 respondents]), and a true endoscopic technique with gas insufflation (12% [11 respondents]). Techniques used to ensure completeness of resection include the quick intraoperative intact parathyroid hormone assay (68% [65 respondents]), a same-day intact parathyroid hormone assay (17% [16 respondents]), and the nuclear probe (14% [13 respondents]). The number of parathyroidectomies performed worldwide increased from 1727 in 1980 to 6977 in 2000 with the average number per surgeon increasing from 23 in 1980 to 45 in 2000. Geographically, 20 (59%) of 34 surveys from the Americas report the use of minimally invasive parathyroidectomy, 23 (56%) of 41 from the Australasian region, and 34 (49%) of 69 from Europe or the Middle East. The number of parathyroidectomies performed for primary hyperparathyroidism has increased worldwide over the past 20 years. More than half of the surgeons responding to the survey perform minimally invasive parathyroidectomy, with the most using the focused small-incision technique.

Intraoperative parathyroid hormone assay (IOPTH) is often used during minimally invasive parathyroidectomy (MIP) for primary hyperparathyroidism (pHPT). However, several investigators have reported conflicting outcomes, throwing doubt on the real influence of this adjunct on surgical decision-making. The aim of this study was to determine the impact of routine use of IOPTH on the success rate of MIP as the primary outcome, and whether it value-added to surgical decision-making during the operations at our institution. The results of MIP were determined on postoperative follow-up in 177 consecutive patients with pHPT and compared with the results of preoperative imaging, findings at surgery and the value-added accuracy of IOPTH in surgical decisions. All 177 patients had biochemically documented pHPT and all were referred for first-time surgery. Group 1 patients (n = 62) underwent a unilateral neck exploration (UNE) without IOPTH, and group 2 patients (n = 115) underwent MIP (either video-assisted or open) with IOPTH. The primary outcome was the cure rate, whereas the secondary outcome was the value-adding of IOPTH to surgical decision-making during MIP. Of the group 1 vs. 2 patients, 57/62 (91.9%) vs. 114/115 (99.1%) were cured (P = 0.01). Five (8.1%) of the group 1 patients were hypercalcaemic postoperatively, owing to an additional, overlooked, hyperfunctioning parathyroid gland, whereas among the 115 group 2 patients, 104 (90.4%) underwent resection of a single parathyroid adenoma, met the Miami criterion, and were cured. The remaining 11 (9.6%) patients did not have an adequate reduction in parathyroid hormone levels and underwent further neck exploration, with resection of additional hyperfunctioning parathyroids in nine of them. One group 2 patient was not cured. However, a decrease of less than 50% of intraoperative parathyroid hormone (iPTH) assay correctly identified the risk of persistent disease in that patient. Another patient in group 2 had a false-negative IOPTH result. The value-added accuracy of IOPTH (correct assay-based surgeon's decision of further neck exploration) was demonstrated in 3 of 78 group 2 patients with concordant results of both imaging studies vs. 7 of 37 group 2 patients with only one positive imaging study, or 3.8 vs. 18.9% of patients (P = 0.007). Routine use of IOPTH significantly improves cure rates of MIP in comparison to open image-guided UNE without IOPTH. It is a valuable adjunct in surgical decision-making, allowing for intraoperative recognition and resection of additional hyperfunctioning parathyroid tissue missed by preoperative imaging studies. IOPTH offers substantial value-adding to surgical decision-making, particularly in patients with only one positive imaging study result, and significantly improves the success rate of MIP in these patients. However, in patients with concordant results of two imaging studies, the assay offers significantly lower value-adding to surgical decisions, as a vast majority of patients are cured after removal of a two-image-indexed parathyroid lesion. Despite this, we strongly advocate routine use of IOPTH in all patients undergoing MIP, as this adjunct offers maximum safety for the patient and confidence for the surgeon.

Localizing studies are the key for determining the optimal surgical strategy in patients with primary hyperparathyroidism (HP). Most of the data in the literature are retrospective in nature and from analysis on a per patient basis. This is a prospective study looking at the characteristics of the patient and the gland that determine the likelihood of an abnormal parathyroid to be detected by ultrasonography (US) and sestamibi scan (MIBI). This is a prospective analysis of 1000 consecutive patients with HP who underwent parathyroidectomy at a tertiary care center. The study group included HP with single gland disease (63%), double adenoma (15%), as well as hyperplasia (15%), familial HP (2%), and secondary/tertiary HP (6%). All patients underwent surgeon-performed neck US followed by MIBI scan. Univariate logistic regression and multivariate analyses were performed on pre- and intraoperative variables. A total of 1845 abnormal glands were analyzed. Overall, US was superior to MIBI for the detection of abnormal glands in all subgroups. On multivariate analysis, body mass index (BMI), gland size, and gland volume were the statistically significant independent factors predicting detection by both US and MIBI in primary HP. The sensitivity of US was better for single gland disease than for multigland disease in primary HP, but the sensitivity of MIBI was similar in both groups. For a given size, hyperplastic glands in primary HP imaged less well with US and MIBI than in familial or secondary/tertiary HP. This prospective study demonstrates that BMI and gland size independently predict accurate detection of abnormal parathyroid glands by US and MIBI in sporadic primary HP. Understanding the factors that affect the accuracy of parathyroid localization tests will allow the surgeon to develop a successful surgical strategy in a given patient.