Parathyroid nuclear scan. A focused review on the technical and biological factors affecting its outcome.

OBJECTIVE: Technetium Parathyroid Scintigraphy (TS) is the most popular noninvasive localization procedure in patients with primary hyperparathyroidism (PHPT). Awareness of various factors involved in technetium uptake helps understand the outcome of TS. METHODS: We utilize a case of changing TS scans in a patient to review the literature on the various biological and technical factors involved in technetium uptake by the abnormal parathyroid tissue. A 56 year female was diagnosed with PHPT and osteopenia. An initial scan using (99m)Tc-Tetrofosmin showed no definite areas of abnormal parathyroid tissue. Patient refused surgical exploration, was started on Bisphosponates and subsequently monitored. Five years later she suffered fracture of her right wrist. A repeat TS using (99m)Tc-Sestamibi revealed hypervascular parathyroid lesion in the right lower neck. She underwent successful removal of a right lower parathyroid adenoma. RESULTS: Technical factors like the type of Tc isotope used, imaging techniques and biological factors like biochemical parameters (calcium, vitamin D levels), adenoma size, content of oxyphilic cells, vascularity can affect the outcome of the scan. CONCLUSION: Clinicians should be aware of technical and biological factors that could result in negative scan in parathyroid nuclear scintigraphy.

Normalization of 2-week postoperative parathyroid hormone values in patients with primary hyperparathyroidism: four-gland exploration compared to focused-approach surgery.

BACKGROUND: Elevation of parathyroid hormone (PTH) levels is commonly seen in patients with primary hyperparathyroidism (PHPT) who have undergone parathyroidectomy. This study evaluates differences in 2-week postoperative PTH levels in patients having focused-approach surgery versus four-gland exploration. METHODS: Over 6 years, patients at Rhode Island Hospital (RIH) and the Cleveland Clinic (CCF) who had PHPT and underwent localization studies suggestive of single adenoma were analyzed. At RIH patients underwent focused-approach surgery, and at CCF routine four-gland exploration was performed. Postoperative calcium supplementation was routine at RIH and selective at CCF. RESULTS: There were 308 patients at RIH and 370 at CCF. They were similar in age (59.2 +/- 13.0 years at RIH and 60.4 +/- 12.9 years at CCF), and sex (76.9 and 80.0% female at RIH and CCF, respectively). The mean preoperative serum calcium measured 10.9 +/- 0.7 mg/dl at RIH and 11.1 +/- 0.7 mg/dl at CCF (P < 0.001). Preoperative PTH values were similar, measuring 143.8 +/- 104.8 pg/ml in the focused-approach group (RIH) and 157.6 +/- 150.3 pg/ml in the four-gland exploration group (CCF). Preoperative 25-hydroxyvitamin D (vitamin D-25) levels were 24.1 +/- 12.0 ng/ml at RIH and 27.4 +/- 10.6 ng/ml at CCF; and the prevalence of vitamin D-25 deficiency (level <20 ng/ml) was 43.9% at RIH and 27% at CCF (P = 0.017). The proportion of patients whose intraoperative PTH value dropped by >or=50% prior to completion of surgery was 95.0% at RIH and 95.5% at CCF. The total gland weight resected per patient was 942 mg at RIH versus 1,394 mg at CCF (P = 0.003). The 2-week postoperative serum PTH was >65 pg/ml in 18.8% at RIH and in 38.7% at CCF (P < 0.001). The 2-week postoperative serum calcium values dropped to 9.2 +/- 0.6 mg/dl at RIH and to 9.5 +/- 0.8 mg/dl at CCF (P < 0.001). The incidence of multigland disease was 5.8% at RIH and 21.9% at CCF (P

Value of intraoperative parathyroid hormone monitoring.

BACKGROUND: 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). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Laparoscopic versus open ventral hernia repairs: 5 year recurrence rates.

BACKGROUND: Current studies with 2-3 year follow-up favor laparoscopic ventral hernia repair due to lower recurrence rates, fewer wound infections, and shorter hospital stays. There is scant data in the literature for this group of patients regarding longer follow-up. This study compares the actual 5 year recurrence rates of laparoscopic versus open techniques and determines factors that may affect recurrence. METHODS: A retrospective analysis of ventral hernia repairs at a tertiary center between January 1996 and December 2001 was performed. In this era, the method of repair often depended on which surgeon evaluated the patient. All patients were followed for a minimum of 5 years (median 7.5 years). Demographic and clinical parameters were analyzed using Kaplan-Meier analyses and the multivariate Cox proportional hazard model. RESULTS: Of 331 patients, 119 underwent laparoscopic ventral hernia repair (LAP), 106 open hernia repair with mesh (O-M), 86 open suture repair (O-S), and 20 laparoscopic converted to open (LCO). Statistical analyses showed equal parameters among groups except defect sizes (mean +/- standard error on the mean [SEM]): LAP (9.8 +/- 1.2 cm), O-M (11.2 +/- 3.3 cm), LCO (16.6 +/- 5.4 cm) versus O-S (4.6 +/- 1.6 cm) (p < 0.02). Actual recurrence rates at 1 and 5 years were LAP (15% and 29%), O-M (11% and 28%), O-S (10% and 19%), and LCO (35% and 60%). Multivariate analysis identified larger defects to have higher recurrence rates, particularly in the O-S group (p < 0.02). With the exception of the LCO group, surgical technique did not predict recurrence, nor did body mass index, diabetes, smoking, or use of tacks versus sutures. CONCLUSION: This is the first study to compare 5 year actual recurrence rates between laparoscopic and open ventral hernia repairs. Contrary to prior reports, our longer-term data indicates similar recurrence rates, except for higher rates in the laparoscopic converted to open group. Due to the continued recurrences over the period studied, longer-term follow-up is necessary to appreciate the true rate of hernia recurrence.

Radionuclide imaging for hyperparathyroidism (HPT): which is the best technetium-99m sestamibi modality?

BACKGROUND: To determine the utility of available radionuclide imaging modalities for preoperative parathyroid localization, we compared the accuracy of 4 types of technetium-99m ((99)Tc) sestamibi-based scans. METHODS: Over 5 years, 833 patients with sporadic primary hyperparathyroidism underwent either (99)Tc-sestamibi with planar views (Planar; n = 138); sestamibi single photon emission computed tomography (SPECT; n = 165); SPECT with thyroid (123)I-subtraction phase (SPECT/(123)I; n = 350); or SPECT combined with conventional CT (SPECT/CT; n = 180). The accuracy of each modality was determined on the basis of intraoperative parathyroid pathology, defined as single adenoma or multigland disease. RESULTS: Planar scans had significantly more false negatives (no tumor visualized) than SPECT-based scans (P < 0.01), but positive predictive values were similar. A false-negative scan was present in 38% of Planar scans, 27% SPECT, 4% SPECT/(123)I, and 17% SPECT/CT, with single adenoma found at operation in 77%, 64%, 53%, and 74%, respectively. When a scan had a single focus of uptake, SA was found at that location in 77%, 85%, 68%, and 87%, respectively. SPECT, SPECT/(123)I, and SPECT/CT did not significantly reduce the false-positive rate. CONCLUSIONS: We recommend obtaining multiplanar SPECT-based imaging, which offers 3-dimensional localization and improved detection of parathyroid tumors when compared with Planar scans. A negative scan did not predict multigland disease.

Complication of thyroidectomy in patients with radiation-induced thyroid neoplasms.

HYPOTHESIS: The complication rate for thyroidectomy is the same in patients with and without a history of radiation exposure. DESIGN: Retrospective medical record review of 171 consecutive patients who had a previous history of radiation treatment and had undergone a thyroid operation from 1961 to 1999. SETTING: University of California, San Francisco, Medical Center and affiliated hospitals. PATIENTS: We selected 107 patients with a history of radiation exposure who had undergone thyroid operations (81 total thyroidectomies) and 107 control patients who underwent comparable operations but had no history of radiation exposure. RESULTS: Among patients with a history of radiation exposure (mean age, 47.2 years), there was 1 recurrent nerve injury, 1 external nerve injury, 20 patients with transient hypocalcemia, and 1 patient with a hematoma. Among patients without a history of radiation exposure (mean age, 47.5 years), there were 2 recurrent nerve injuries, 18 patients with transient hypocalcemia, and 1 patient with a hematoma. All cases of hypocalcemia and recurrent nerve injury in both groups were transient. One patient had a permanent superior laryngeal nerve injury. In patients who underwent operations since January 1, 1990, duration of hospitalization was 1.2 days in patients with a history of radiation exposure (65 patients) and 1.1 days in patients without (101 patients). CONCLUSIONS: Our data document that the risk of transient and permanent complications after total thyroidectomy is similar in patients with and without a history of radiation exposure. The relatively low long-term complication rate supports prophylactic total thyroidectomy for patients with thyroid nodules and a history of radiation exposure.