Surgeon-performed ultrasound improves localization of abnormal parathyroid glands.

With a secure diagnosis of hyperparathyroidism, preoperative localization of abnormal glands is the initial step toward limited parathyroidectomy (LPX). We investigated whether ultrasonography in the hands of the surgeon (SUS) could improve the localization of abnormal parathyroids when sestamibi scans (MIBI) were negative or equivocal. One hundred eighty patients with sporadic primary hyperparathyroidism (SPHPT) underwent preoperative SUS and MIBI scans before LPX guided by intraoperative parathormone assay. When the sestamibi scans were negative, SUS was used to localize the parathyroid, distinguish parathyroid from thyroid tissue, and to guide the intraoperative jugular venous sampling for differential elevation of parathyroid hormone (PTH). Operative findings, intraoperative hormone dynamics, and postoperative calcium levels determined successful localization. MIBI was negative or equivocal in 36/180 (20%) patients: (1) showed no parathyroid gland in 22 patients, (2) suggested an incorrect location for the abnormal gland in 9, and (3) was insufficient in recognizing multiglandular disease in 5. In these 36 patients, the addition of SUS led to the successful identification of the abnormal tissue in 19/36 (53%). In the remaining 17 patients with negative/equivocal scans, the parathyroid could not be clearly visualized by SUS. In these patients, SUS facilitated LPX by aiding preoperative transcutaneous jugular venous sampling for differentially elevated PTH (n=3) and identifying questionable thyroid nodule versus parathyroid tissue (n=1). Overall, SUS was useful in 23/36 (67%) patients with nonlocalizing MIBI scans, thus improving the rate of localization from 80 per cent to 93 per cent (P < 0.01). Surgeon-performed cervical ultrasonography improved the localization of abnormal parathyroids by MIBI scan, adding to the success of limited parathyroidectomy.

Quick intraoperative parathyroid hormone assay: surgical adjunct to allow limited parathyroidectomy, improve success rate, and predict outcome.

Intraoperative parathyroid hormone (PTH) assay (QPTH) has made possible less invasive operative approaches in the treatment of primary hyperparathyroidism with stated advantages. When compared to the traditional bilateral neck exploration (BNE), only the targeted, hypersecreting gland is excised, leaving in situ non-visualized but normally functioning parathyroids. The QPTH-guided limited parathyroidectomy (LPX) must be able to identify multiglandular disease (MGD), predict a successful outcome, and have a low recurrence rate. In our series, 421 patients who underwent LPX were compared to 340 undergoing BNE; all operative failures and patients followed for 6 months or longer were included. Operative failure occurred if serum calcium and PTH levels were elevated within 6 months of parathyroidectomy. Multiglandular disease was defined in the LPX group as more than one gland excision guided by QPTH or operative failure after removal of a single abnormal gland; in the BNE group it was defined as excision of more than one enlarged gland. Recurrence was defined as elevated calcium and PTH after 6 months of eucalcemia. Operative failure and MGD rates were compared using chi-squared analysis. The method of Kaplan-Meier and the log-rank test were used to compare recurrence rates. Operative success was seen in 97% of LPX patients and in 94% of the BNE group ( p = 0.02). Multiglandular disease was identified in 3% of LPX patients and 10% of BNE patients ( p < 0.001). There was no statistical difference in the overall recurrence rates ( p = 0.23). The QPTH-guided parathyroidectomy identifies MGD and allows an improved success rate with the same low recurrence rate when compared to the results of BNE.

Recurrent disease after limited parathyroidectomy for sporadic primary hyperparathyroidism.

BACKGROUND: Limited parathyroidectomy guided by intraoperative parathyroid hormone (PTH) assay (QPTH) is highly successful (97% to 99%) in predicting postoperative eucalcemia, usually with less extensive dissection when compared with bilateral neck exploration. Because fewer glands are excised when resection is guided by QPTH as opposed to resection guided by gland size, a higher recurrence rate may occur. Recurrence rate after bilateral neck exploration is 0.4% to 5%, but frequency of recurrence after limited parathyroidectomy is unknown. This study reports outcomes of this operative approach in sporadic primary hyperparathyroidism. STUDY DESIGN: Four-hundred twenty-three patients with sporadic primary hyperparathyroidism undergoing limited parathyroidectomy, followed 6 months or more or considered operative failures, were studied. In most patients, calcium and PTH levels were measured immediately after operation, and then at 2 and 6 months and yearly intervals. Operative failure is defined as hypercalcemia and high PTH within 6 months after operation, and recurrent hyperparathyroidism is hypercalcemia and elevated PTH occurring after a successful parathyroidectomy. Recurrence distributions were estimated using Kaplan-Meier analysis. RESULTS: The success rate of limited parathyroidectomy is 97% (412/423). Four-hundred six patients were eucalcemic over an average of 34 months (median 27, range 6 to 118 months) of followup and recurrent hyperparathyroidism developed in 6 of 412 (1.5%). Estimated 5 years recurrence-free rate was 97% (95% confidence interval, 91% to 99%). Earliest and latest recurrences were diagnosed at 24 and 83 months, respectively. QPTH results did not predict any recurrence. Overall success rate was achieved, with multiple gland resections performed in only 3% of patients. CONCLUSIONS: Recurrence rate after limited parathyroidectomy is similar to rates reported after bilateral neck exploration. Parathyroidectomy guided by QPTH is successful not only in resolving hypercalcemia in the short term, but also in providing longterm eucalcemia.

Surgeon-performed ultrasound in the management of thyroid malignancy.

Surgeon-controlled real-time ultrasound (US) is a new adjunct in the management of patients with thyroid malignancy. The introduction of US as a routine evaluation tool has increased the recognition of nonpalpable thyroid cancers and cervical lymph node metastases. We report our experience and the change in management of patients with thyroid cancer due to the use of US. We reviewed the records of all patients undergoing neck operations for thyroid cancer since 2002. US was performed by a surgeon preoperatively in all patients and intraoperatively when non-palpable cervical lymph nodes were present. Suspicious nonpalpable thyroid nodules underwent US-guided fine-needle aspiration (FNA) for cytology. Seventy-two patients underwent operations for thyroid cancer. US influenced the management in 57 per cent (41/72) of patients. US was useful in 1) identification and guidance for the FNA of nonpalpable cancers in 28 per cent (20/72), 2) identification of nonpalpable nodules in the contralateral lobe in 38 per cent (27/72), 3) preoperative diagnosis of nonpalpable metastatic lymph nodes in 24 per cent (17/72), and intraoperative guidance for their excision. Surgeon-performed US changed and enhanced the pre- and intraoperative management in more than half the patients with thyroid cancer.

Progress in the operative management of sporadic primary hyperparathyroidism over 34 years.

BACKGROUND: Progress in the diagnosis, localization of abnormal parathyroids, and intraoperative management of primary hyperparathyroidism has been observed over the past 34 years. The goal of this study is to report the outcome of patients undergoing 2 different operative approaches in a single institution, showing the evolution of surgical management of sporadic primary hyperparathyroidism (SPHPT). METHODS: Parathyroidectomy was performed in 890 (827 initial, 63 reoperative) patients with SPHPT using 2 different approaches: traditional bilateral neck exploration (BNE, n = 396) or limited parathyroidectomy guided by parathormone dynamics (LPX, n = 494). Seven hundred eighteen patients (335 BNE, 383 LPX) followed > or = 6 months or identified as operative failures were studied. Operative failure is defined as hypercalcemia and high intact (1-84) parathyroid hormone molecule (iPTH) within 6 months after operation. Successful parathyroidectomy is normocalcemia for 6 months; hypercalcemia and elevated iPTH after this time is recurrent hyperparathyroidism. RESULTS: There were 20 (6%) of 335 operative failures in the BNE group and 11 (3%) of 383 failures in the LPX group (P = 0.04). The incidence of multiglandular disease (MGD) determined by gland size (10%) versus hormone hypersecretion (3%) was statistically different (P < 0.001). Since most of the recurrences occurred later than 30 months, the incidence of recurrent hyperparathyroidism in patients followed for longer than 2.5 years was 4% (11/287) in the BNE group (average, 11.5 years) and 3% (5/183) in the LPX group (average, 4.2 years). CONCLUSION: LPX, with its reported advantages of minimal dissection, shorter operative time, and use in ambulatory settings, compares favorably with the traditional BNE. Parathyroidectomy guided by parathormone dynamics has an improved success rate and should be considered as a standard operative approach in SPHPT.

Comparison of intraoperative iPTH assay (QPTH) criteria in guiding parathyroidectomy: which criterion is the most accurate?

BACKGROUND: The quick parathyroid hormone assay (QPTH) reliably measures intact parathyroid hormone (iPTH) levels intraoperatively. The accuracy in predicting postoperative calcemia is related to blood sample timing and the criteria applied. To improve specificity or to decrease the cost of QPTH, several criteria have been used to predict complete excision. This study compares the Miami criterion with other published QPTH criteria in predicting operative outcome. METHODS: QPTH and the Miami criterion (iPTH drop > or =50% from the highest of either preincision or pre-excision level at 10 minutes after gland excision), were used to predict postoperative calcium levels of 341 consecutive patients with sporadic primary hyperparathyroidism who were followed > or =6 months after the operation or recognized as operative failures. Intraoperative iPTH values of these patients were reanalyzed with the use of 5 published criteria to predict complete resection. Postoperative calcium levels were correlated with criteria predictions. RESULTS: Miami criterion correctly predicted postoperative calcium levels in 329 of 341 patients and was incorrect in 12 (3 false positives, 9 false negatives). With the use of other criteria, 2 of the 3 false-positive results would be prevented, but the 3% rate of false-negative predictions would increase to between 6% and 24%, causing unnecessary neck explorations to search for multiglandular disease. CONCLUSIONS: Surgeons trying to increase QPTH specificity significantly decrease the accuracy and intraoperative usefulness of the assay. The Miami criterion has the highest accuracy when compared with other criteria.

Rapid insulin assay for intraoperative confirmation of complete resection of insulinomas.

BACKGROUND: Solitary insulinomas are usually the cause of organic hypoglycemia, whereas 13% to 24% of patients with hyperinsulinemia have multiple tumors or nesidioblastosis. Intraoperative glucose levels confirming complete excision have variable accuracy. Intraoperative insulin levels have been shown to predict operative outcome. The purpose of this study was to establish criteria for predicting operative success by using a new, rapid insulin assay as an intraoperative adjunct. METHODS: Eight consecutive patients with organic hypoglycemia underwent pancreatic exploration. With an 8-minute immunochemiluminescent insulin assay, peripheral blood levels were obtained preoperatively, during resection, and at 5-minute intervals after surgical excisions. Operative findings and outcome were compared with intraoperative insulin/glucose ratios (I/G), glucose, and insulin levels. RESULTS: By using the return of insulin levels to normal range and I/G ratios < or = 0.4 15 minutes after tumor(s) resection as criteria to predict operative success, 6 patients had their outcomes correctly predicted (5 true-positive and 1 true-negative). One patient with nesidioblastosis had a false-negative result. One could not be evaluated because of diazoxide medication. These criteria predicted postoperative absence of hypoglycemia with specificity of 100% and accuracy of 89%. CONCLUSIONS: These 8-minute insulin assay and criteria can be a useful adjunct for intraoperative assurance of complete insulinoma resection and prediction of postoperative outcome.

Limited versus radical parathyroidectomy in familial isolated primary hyperparathyroidism.

BACKGROUND: Familial isolated primary hyperparathyroidism (FIHPT) is characterized by earlier onset, higher incidence of multiglandular disease, and higher recurrence rate when compared with sporadic primary hyperparathyroidism. Excision of 3.5 or 4 glands with autotransplantation has been recommended; however, these approaches lead to permanent hypoparathyroidism in 13% to 41% of patients. It is reported that many patients with FIHPT return to normocalcemia after single-gland excision. The use of preoperative localization and intraoperative parathyroid hormone assay permits limited resection of only hypersecreting glands. We report the outcome of this operative approach. METHODS: Fifteen consecutive patients with FIHPT underwent limited parathyroidectomy with resection guided by intact parathyroid hormone secretion in 2 university centers. Patients were followed up postoperatively for serum calcium and intact parathyroid hormone levels. RESULTS: With an operative success of 93%, 14 patients had only single-gland excision and 80% had unilateral neck exploration. All initial patients had their hypercalcemia corrected. In 4 reoperations, permanent hypoparathyroidism occurred in 2 patients. One recurrence was observed in 40 (8-122) months of follow-up. CONCLUSION: Limited parathyroidectomy allows successful single-gland excision in many patients with FIHPT, thus decreasing the risk of hypoparathyroidism. In these patients, a low incidence of hypoparathyroidism may be preferable to the possibility of late recurrence.

New point-of-care intraoperative parathyroid hormone assay for intraoperative guidance in parathyroidectomy.

The use of the intraoperative parathyroid hormone assay (QPTH) to guide a limited parathyroidectomy in patients with sporadic primary hyperparathyroidism (SPHPT) is well established. The advantage of having this assay performed in the operating room is immediate feedback for (1) confirming the complete excision of all hyperfunctioning parathyroid(s); (2) differential jugular venous sampling for localization; and (3) diagnosing suspected tissue without histopathology. For these reasons, the reliability of the hormone measurement and a short assay turnaround time are essential for surgical guidance. We report our experience using a new "point-of-care" assay for intact parathyroid hormone (iPTH). A new two-site chemiluminescent immunometric assay was used. The antibodies are inside a microtiter well, where the iPTH is measured by a strip luminometer after incubation for 5 minutes. Sixteen frozen samples were measured simultaneously using the traditional iPTH assay and this new assay for comparison. Fifty-one patients with SPHPT underwent parathyroidectomy guided by this new assay. The criteria used to predict postoperative normocalcemia was a drop in the hormone level of < or = 50% from the highest preincision or preexcision levels at 10 minutes after excision of all hypersecreting gland(s). The correlation between the traditional and new assays was 0.98. The assay predicted the postoperative calcium levels in all patients except one (false negative-delayed drop). The assay turnaround time was 8 minutes. This new point-of-care assay is reliable for predicting postoperative calcium levels when used with the described criteria. It has advantages over the traditional assay in that it is faster and easier to perform.