Use Of Intraoperative Parathyroid Hormone Research Articles

Reoperative parathyroidectomy: An algorithm for imaging and monitoring of intraoperative parathyroid hormone levels that results in a successful focused approach

Advances in preoperative imaging and use of intraoperative parathyroid hormone (IOPTH) levels are changing the approach to reoperative parathyroidectomy (ReopPTX). We sought to develop a protocol for imaging and IOPTH monitoring that allows for a focused, successful operative approach. We reviewed our prospective database of consecutive patients with primary hyperparathyroidism who underwent ReopPTX with IOPTH monitoring between December 1999 and June 2007. Thirty-nine patients underwent 43 ReopPTXs for persistent (79%)/recurrent (21%) disease. All underwent ultrasonography and sestamibi imaging; 24 cases (56%) underwent additional imaging studies. Sensitivity of ultrasonography was 56%, sestamibi 53%, both studies 67%, computed tomography (CT) 48%, magnetic resonance imaging (MRI) 67%, and selective venous sampling (SVS) 50%. IOPTH monitoring predicted accurately cure in 100% and failure in 78%. A focused/unilateral approach was performed in 60%; median operative time was 45 minutes (range, 12-127). At last follow-up, 36 (92%) patients were normocalcemic. We propose that ultrasonography and sestamibi studies should be done before all ReopPTXs; failure to localize should prompt sequential CT, MRI, and SVS until localization is achieved. IOPTH monitoring defines cure and is recommended for all ReopPTXs. This algorithm allows for a focused operative approach in >50% of ReopPTXs with operative times comparable with first-time, minimally invasive parathyroidectomy.

Value of Intraoperative Parathyroid Hormone Monitoring

Routine use of intraoperative parathyroid hormone (IOPTH) has been challenged in both unilateral/limited (LE) and bilateral exploration (BE). To investigate this, we assessed the usefulness of IOPTH in surgical management of primary hyperparathyroidism and parathyroid carcinoma (PC). Between 1998 and 2006, 1133 patients were explored for hyperparathyroidism: 185 LE, 743 BE with IOPTH, 95 BE without IOPTH, 110 reoperations, and 4 PCs. IOPTH patterns were correlated with parathyroid pathology (single adenoma [SA] or multigland disease [MGD]) and operative success. In LE, IOPTH returned to normal in 78% of patients; all patients had SA, and 99% were cured at a mean +/- SEM of 1.2 +/- .24 years; 22% of LE patients (n = 41) whose IOPTH did not return to normal were converted to BE, and all had MGD. BE with and without IOPTH was equally successful 97% and 98% (P = NS) of the time, respectively. In BE in which IOPTH did not return to normal, 9% of patients remained hypercalcemic; tumor distribution mirrored other BE patients (75% SA, 25% MGD). In reoperations, a normal final IOPTH correlated with cure in 99%; otherwise, 59% had persistent disease. Differential bilateral internal jugular vein IOPTH sampling lateralized disease in 77% of reoperations. IOPTH is an important adjunct for successful LE by identifying the presence of MGD and avoiding operative failure. IOPTH adds little to BE; however, final IOPTH values may predict persistent disease in BE, reoperations, and PCs.

Contemporary parathyroidectomy: exploiting technology

Background Conventional parathyroidectomy, as practiced only 10 years ago, has given way to considerable change, largely as a result of the evolution of technology. Several of these important technologies include radio-guided surgery, ultrasound imaging, high-resolution endoscopy, and rapid intraoperative parathyroid hormone (IOPTH) monitoring. Modern parathyroid surgeons should maintain familiarity with the appropriate role of these approaches. Study design Evidence-based analysis of state-of-the-art approaches to the diagnosis and management of primary hyperparathyroidism. Methods and materials Four distinct technologies are analyzed in detail, with particular attention to their impact on the practice of parathyroid surgery. These include radio-guided surgery, ultrasound imaging, high-resolution endoscopy, and IOPTH. Results Each of the technologies examined has substantial value in the current practice of parathyroidectomy. Judicious implementation of these technologies will vary from practice to practice. Radio-guided surgery may obviate the need for IOPTH monitoring, therefore resulting in the fastest procedural times. Ultrasound imaging is useful as an adjunct to sestamibi scanning to localize adenomatous parathyroid glands. Endoscopic techniques facilitate visualization through small openings and may help surgeons achieve minimal access incisions. Finally, the use of IOPTH is a useful adjunct to directed explorations, and it imparts confidence that all hyperfunctioning parathyroid tissue has been removed. Conclusions The practice of parathyroid surgery has undergone tremendous change in the past decade, and this change has largely been a technology-driven phenomenon. Acquisition of familiarity and skill with these new technologies will be necessary for the endocrine head and neck surgeon wishing to stay abreast of modern surgical techniques and provide quality care.

Use of Monitoring Intraoperative Parathyroid Hormone During Parathyroidectomy in Patients on Waiting List for Renal Transplantation

This report describes the use of intraoperative parathyroid hormone (ioPTH) assay during parathyroidectomy for patients with secondary hyperparathyroidism on the waiting list for renal transplantation. The levels of ioPTH were determined among waiting list patients undergoing subtotal parathyroidectomy and tertiary hyperparathyroidism patients undergoing procedures. The levels of ioPTH were significantly reduced at 10 minutes by 59.7,3% among with secondary hyperparathyroidism and 68.9% among tertiary hyperparathyroidism. A 15 minutes it was 85% in secondary hyperparathyroidism and 89.7% in tertiary hyperparathyroidism. A decrement of 50% in basal values at 10 minutes and 85% decrement or more at 15 minutes was predictive for the success of abnormal parathyroid gland removal. The application of this technique during subtotal parathyroidectomy results was useful to predict a correct excision of abnormal parathyroid glands among patients with secondary hyperparathyroidism on the waiting list and for tertiary hyperparathyroidism patients.

Article Commentary: Current Applications of the Intraoperative Parathyroid Hormone Assay in Parathyroid Surgery

Parathyroid hormone measurement using a two-site immunochemiluminometric assay has allowed for a rapid and accurate technique that has found its way into the operative armamentarium of some parathyroid surgeons. It can be used to assess the completeness of parathyroid gland resection and allow for a minimally invasive parathyroidectomy. This operative approach has become a popular marketing tool, providing patients with confidence in their surgical outcome. The purpose of this review is to provide the surgeon with the practical points and pitfalls of the use of intraoperative parathyroid hormone in the treatment of parathyroid disease.

Minimally invasive parathyroidectomy without intraoperative parathyroid hormone monitoring in patients with primary hyperparathyroidism

Minimally invasive parathyroidectomy (MIP) is the preferred operation for patients with primary hyperparathyroidism (HPT) and positive preoperative imaging. This non-randomized case series assessed the long-term results of MIP performed without the use of intraoperative parathyroid hormone (ioPTH) monitoring. The study involved prospective collection of demographic, biochemical and operative details on a consecutive, unselected cohort of 298 patients who underwent surgery for non-familial primary HPT during a 5-year interval. The mean preoperative serum calcium level was 3.00 mmol/l with a mean parathyroid hormone concentration of 25.8 pmol/l. (99m)Tc-labelled sestamibi scanning and neck ultrasonography were performed in 262 patients. Sestamibi scan showed unilateral uptake in 182 patients and a single parathyroid adenoma was confirmed on ultrasonography in 161 patients. MIP was performed in 150 patients. The mean duration of operation was 25 (range 8-65) min. Four patients needed conversion to conventional neck exploration. There was one postoperative haematoma and three cases of temporary recurrent laryngeal nerve neuropraxia. All but four patients were normocalcaemic after MIP. All the parathyroid tumours removed were adenomas, with a mean weight of 1.3 (range 0.1-17.4) g. No patient developed recurrent HPT after a median follow-up of 16 (range 3-48) months. The outcome of MIP without ioPTH monitoring was comparable to that reported in series that used ioPTH monitoring.

Accuracy of intra-operative PTH measurement during subtotal parathyroidectomy for tertiary hyperparathyroidism after renal transplantation

Intra-operative parathyroid hormone (IOPTH) results are not known in the setting of tertiary hyperparathyroidism (HPT) after renal transplantation. A retrospective analysis of 35 tertiary HPT patients who all underwent subtotal parathyroidectomy and IOPTH monitoring was conducted. The mean follow-up time was 2.2+/-1.4 years. Thirty-four patients were cured; one patient (2.8%) had a persistent disease and was cured after reoperation. Median parathyroid hormone (PTH) (median percent decrease from highest) at baseline and at 5, 10, 20, and 30 min were 244, 78 (69%), 63 (75%), 53 (79%), and 49 pg/ml (83%), respectively. Four patients who were cured had a decrease of <50% at 5 min and two of them had a decrease of <50% at 10 min. The patient with persistent disease had a decrease of >50% at 10 min. The sensitivity of the test was 94% at 10 min using the Miami criteria. This study shows that IOPTH in tertiary hyperparathyroidism has a high sensitivity. However, because of the low risk of persistent hyperparathyroidism when a subtotal parathyroidectomy is performed, its potential impact on the overall success rate is very small. We therefore do not recommend the routine use of IOPTH in tertiary hyperparathyroidism.

Predictors of Single-Gland vs Multigland Parathyroid Disease in Primary Hyperparathyroidism

Preoperative clinical, biochemical, and imaging studies could be used to reliably select patients with single-gland primary hyperparathyroidism who could undergo minimally invasive parathyroidectomy and to determine whether additional perioperative testing is necessary. Retrospective analysis. Tertiary referral center. A total of 238 patients who underwent neck surgical exploration and parathyroidectomy for primary hyperparathyroidism from January 7, 2002, to December 23, 2004. Demographic, clinical, biochemical, and imaging factors that predict single-gland vs multigland parathyroid disease, and biochemical cure. Of the 238 patients, 75.2% had a single adenoma, 21.4% had asymmetric 4-gland hyperplasia, and 3.4% had double adenomas. A biochemical cure was achieved in 99.2% of the patients. Preoperative calcium and intact parathyroid hormone levels were significantly higher (P = .03 and .04, respectively) and ultrasound and sestamibi scan results were more likely to be positive (both P<.001) in single-gland primary hyperparathyroidism. A dichotomous scoring model based on preoperative total calcium level (>/=3 mmol/L [>/=12 mg/dL]), intact parathyroid hormone level (>/=2 times the upper limit of normal levels), positive ultrasound and sestamibi scan results for 1 enlarged gland, and concordant ultrasound and sestamibi scan findings reliably distinguished single-gland vs multigland cases (P<.001). The positive predictive value of this scoring model to correctly predict single-gland disease was 100% for a total score of 3 or higher. Preoperative biochemical and imaging study results reliably distinguished single-gland vs multigland parathyroid disease in primary hyperparathyroidism. Our findings suggest that patients with a score of 3 or higher can undergo a minimally invasive parathyroidectomy without the routine use of intraoperative parathyroid hormone or additional imaging studies, and those with a score of less than 3 should have additional testing to ensure that multigland disease is not overlooked.

Intra‐operative parathyroid hormone monitoring in secondary hyperparathyroidism: is it useful?

To assess the use of intra-operative parathyroid hormone (PTH) level monitoring as a predictor of persistent hypoparathyroidism after total parathyroidectomy in renal hyperparathyroidism. University Teaching Hospital Otorhinolaryngology and Head and Neck Surgery Unit. All patients with renal hyperparathyroidism undergoing parathyroidectomy between January 2004 and July 2005. Twenty-nine patients were identified. Comparison is made between pre- and intra-operative PTH levels (ioPTH) in patients who at 3 months postoperatively maintained hypoparathyroidism and patients who did not. Results were analysed to see whether ioPTH predicts maintenance of the hypoparathyroid state. The mean preoperative PTH level was 932 pg/L (range: 58-1808). The mean postoperative PTH level was 147 pg/L (range: 16-498). The mean 3-month PTH level was 47 pg/L (range: <1-515). The mean postoperative PTH level for patients with a persistently high PTH level at 3 months was 286 pg/L (range: 272-299), compared with 63 pg/mL (16-160) in patients remaining normparathyroid, and 159 pg/L (range: 39-498) for patients with persistent hypoparathyroidism. If the normoparathyroid state is strictly considered to be failure following total parathyroidectomy, ioPTH is not predictive of hypoparathyroidism. However, ioPTH is indicative of biochemical resolution of the hyperparathyroid state (normo- or hypoparathyroidism). We conclude that the use of ioPTH monitoring in the surgical management of secondary hyperparathyroidism fails to predict persistent hypoparathyroidism following total parathyroidectomy, but does predict biochemical resolution of hyperparathyroidism.

Reassessment of Parathyroid Hormone Monitoring During Parathyroidectomy for Primary Hyperparathyroidism After 2 Preoperative Localization Studies

For patients with primary hyperparathyroidism and patients with 2 localization studies showing the same single location of parathyroid disease, use of intraoperative parathyroid hormone (IOPTH) measurement does not significantly increase the success of minimally invasive parathyroidectomy. Retrospective cohort study. Experience of 2 academic centers over 5 years (at Brigham and Women's Hospital, Boston, Mass) and almost 4 years (at Rhode Island Hospital, Providence). A total of 569 patients with primary hyperparathyroidism who underwent technetium Tc 99m sestamibi (MIBI) parathyroid imaging and neck ultrasonography (US). Incidence of correct prediction of location and extent of disease. In 322 patients (57%), MIBI and US imaging identified the same single site of disease. In 319 (99%) of these 322 patients, surgical exploration confirmed a parathyroid adenoma at that site, and the IOPTH levels normalized on removal. In 3 (1%) of the 322 patients, IOPTH measurement identified unsuspected additional disease. In 3 (1%) of the remaining 319 patients, IOPTH-guided removal of a single adenoma failed to correct hypercalcemia. Therefore, the failure rate of surgery in patients with positive MIBI and positive US imaging was 1% with IOPTH measurement and 2% without IOPTH measurement (P = .50). In 201 (35%) of the 569 patients, only 1 of the 2 studies recognized an abnormality or the studies disagreed on location. In these cases, either MIBI imaging or US imaging (if MIBI imaging was negative) failed to predict the correct site or extent of disease in 76 (38%) of the 201 patients (P<.001 vs concordant studies). In primary hyperparathyroidism, concordant preoperative localization with MIBI and US imaging is highly accurate. Use of IOPTH measurement in these cases adds only marginal benefit. When only 1 of the 2 studies identifies disease or the studies conflict, however, IOPTH measurement remains essential during minimally invasive parathyroidectomy.

Measurement of parathyroid hormone in patients with primary hyperparathyroidism undergoing first and reoperative surgery.

The distinction between solitary parathyroid adenoma and hyperplasia can sometimes be difficult during surgery for primary hyperparathyroidism (pHPT), especially in patients who have undergone previous thyroid or parathyroid surgery. The use of intraoperative parathyroid hormone (PTH) monitoring as a possible diagnostic tool was therefore investigated. Intraoperative levels of PTH were measured in 119 patients during 121 operations (including 14 reoperations) for pHPT. The mean(s.d.) preoperative serum calcium level was 2.79(0.21) mmol/l. Blood samples were drawn before, and at 5 and 15 min after, excision of the first enlarged parathyroid gland. PTH was analysed electively in 61 patients and on-line by a modified assay for intact PTH in 48 patients. Both procedures were used in ten patients. The mean(s.d.) decline in PTH concentration in 101 patients with primary exploration due to solitary adenoma was 63(17) per cent after 5 min (n=84) and 83(10) per cent after 15 min. The patients with primary exploration because of multiglandular disease (n=6) were correctly predicted not to have parathyroid adenoma. Measurement of PTH levels during surgery for pHPT is a highly sensitive method for differentiating between single and multiple gland disease. The on-line monitoring of PTH is clinically useful in patients who have undergone previous neck surgery. Its role in pHPT surgery at primary exploration should be evaluated in prospective trials.