Parathyroid Exploration Research Articles

S178 – Utility of CT-Sestamibi Fusion in Parathyroid Exploration

Objectives 1) Delineate the role of CT-technetium 99m sestamibi (CT-MIBI) fusion in directed parathyroidectomy. 2) Determine the clinical situations where CT-MIBI fusion would be strongly recommended. Methods Charts from 190 patients with primary hyperparathyroidism who underwent CT-MIBI mage fusion as a part of a scan directed, minimally invasive parathyroid exploration protocol were reviewed. The results of conventional sestamibi imaging and CT-MIBI image fusion were compared with operative findings. Results CT-MIBI image fusion accurately localized solitary hyperfunctional parathyroid glands in 70% of patients imaged; 55% of patients were localized with conventional sestamibi imaging. CT-MIBI fusion imaging was most accurate and predictive when conventional images suggested that the solitary gland was separated from the thyroid or when the adenoma was located in the retro-thyroidal/ retro-esophageal plane or mediastinum. Conclusions CT-MIBI image fusion is not superior to conventional sestamibi imaging when utilized for routine localization of hyperfunctional parathyroid glands. CT-MIBI fusion is of greatest benefit in guiding the directed approach to solitary glands, which are separate from the thyroid or ectopically located, regions where conventional imaging has proven to be less accurate. This imaging technique will augment the minimally invasive surgical approach in selected patients with primary hyperparathyroidism in order to further refine the focused technique. Its utility as the standard preoperative localization modality is not yet established and requires further investigation. Evaluation of differences in facility utilization with CT-MIBI image fusion and conventional sestamibi imaging may be helpful in determining its role in preoperative localization for hyperparathyroidism.

Appropriate Surgical Treatment of Lithium‐Associated Hyperparathyroidism

Lithium is frequently used in the treatment of bipolar disease. Although lithium-associated hyperparathyroidism (LAH) is well documented, reports concerning its pathologic findings are sparse. Because of a high-reported incidence of multiglandular disease, focused exploration for LAH is controversial. From 1995 to 2007, data from 1207 consecutive patients who underwent concise parathyroid exploration for sporadic primary hyperparathyroidism (PHP) directed by quick intraoperative parathyroid hormone monitoring (QPTH) were reviewed to identify patients with LAH. Anatomic findings were determined. All patients had >5 months of follow-up. The incidence of LAH was 16/1207 (1.3%). The rate of multiglandular disease was not higher in LAH: present in 25% (4/16) patients with LAH and 12.3% (146/1191) patients without LAH (p = 0.13 Fisher two-tailed test). Among 16 patients with LAH, 12 (75%) had a single adenoma. The use of QPTH allowed unilateral exploration in 8 of 12 patients with single adenoma. Parathyroid exploration resulted in durable biochemical cure for all 16 patients with LAH. Multiglandular disease seems to be no more frequent in patients with LAH than in patients with primary hyperparathyroidism (PHP) without LAH. Patients with LAH can be safely and effectively managed with selective unilateral exploration directed by intraoperative PTH monitoring.

Parathyroid Exploration in the Reoperative Neck: Improved Preoperative Localization with 4D-Computed Tomography

Reoperation for hyperparathyroidism (HPT) carries an increased risk for morbidity and failure to cure. Accurate preoperative localization minimizes operative risk but is often difficult to achieve in the reoperative setting. Four-dimensional computed tomography (4D-CT) is an emerging technique that uses functional parathyroid anatomy for precise preoperative localization. We evaluated 4D-CT as a tool for localization of hyperfunctioning parathyroid tissue in the reoperative setting. A prospective endocrine database was queried to identify 45 patients who underwent reoperative parathyroidectomy after preoperative localization using 4D-CT. The patients were categorized into 1 of 3 groups: group 1 included those who had previous neck surgery for non-HPT conditions; group 2 included those who had undergone a previously unsuccessful neck exploration for HPT; and group 3 included patients with HPT who had a previous neck exploration with resection of at least 1 hypercellular parathyroid. The sensitivity of 4D-CT for localization was 88% compared with 54% for sestamibi imaging. Four-dimensional CT more often correctly localized (p=0.0003) and lateralized (p=0.005) hyperfunctional parathyroid tissue than sestamibi did. Four-dimensional CT successfully localized hyperfunctional parathyroid tissue in 18 (82%) of 22 group 1 patients, 10 (91%) of 11 group 2 patients, and 8 (67%) of 12 group 3 patients. Three patients were lost to followup. At a mean followup of 9.8 months, 39 (93%) of 42 patients were surgically cured and 3 patients (7%; 2 in group 3) had persistent HPT. Four-dimensional-CT is an ideal tool for preoperative localization of hyperfunctioning parathyroid tissue in the reoperative setting. Localization and successful reoperation are most difficult in patients who have undergone an earlier operation that included resection of at least one hypercellular parathyroid suggesting multigland disease.

Can a Lightbulb Sestamibi SPECT Accurately Predict Single‐Gland Disease in Sporadic Primary Hyperparathyroidism?

Technetium-99m sestamibi scintigraphy with single photon emission computed tomography (SPECT) is widely used to guide minimally invasive exploration in patients with sporadic primary hyperparathyroidism (SPH), although its sensitivity in multiglandular disease is limited. We examined the incidence of missed multiglandular disease and associated anatomic findings when sestamibi SPECT was positive for a single intense focus of delayed tracer uptake, termed a lightbulb scan (LBS). Prospectively entered data from 764 patients with SPH treated with initial parathyroid exploration from March 5, 2000, to December 31, 2006, were reviewed. A single radiologist performed blinded interpretation of 585 available sestamibi SPECT images, classifying 167 (28.5%) patients with a LBS. Clinical findings were compared among LBS patients with a single adenoma (true positive) and LBS patients with multiglandular disease (false negative). One hundred fifty of 167 (89.8%) LBS patients had a single adenoma and 3 (1.8%) had carcinoma. Multiglandular disease was anatomically present in 14 of 167 (8.4%) LBS patients compared with 60 of 418 (15.6%) non-LBS patients (p=0.05). Parathyroid hyperplasia occurred less frequently in LBS patients [5/167 (3%)] compared with non-LBS patients [36/418 (8.6%)], (p=0.02), while double adenomas occurred equally often in LBS patients [9/167 (5.4%)] compared with non-LBS patients [24/418 (5.7%)], (p=0.87). Double adenomas in LBS patients were more likely ipsilateral (7/9, p=0.005) and left-sided (7/7, p=0.008). LBS patients with multiglandular disease were more likely to have a history of neck irradiation, prior neck exploration, and concomitant thyroid pathology. In patients with SPH, sestamibi SPECT studies show a single bright focus of uptake in only 29% of patients. LBS findings do not exclude multiglandular disease. To avoid unacceptable rates of failure at initial parathyroid exploration, the expert surgeon should use validated adjuncts such as intraoperative PTH monitoring or four-gland exploration.

Unilateral Versus Bilateral Neck Exploration for Primary Hyperparathyroidism

To compare long-term patient outcome in a prospective randomized controlled trial between unilateral and bilateral neck exploration for primary hyperparathyroidism (pHPT). Minimal invasive and/or focused parathyroidectomy has challenged the traditional bilateral neck exploration for pHPT. Between 1997 and 2001, we conducted the first unselected randomized controlled trial of unilateral versus bilateral neck exploration for pHPT. The results showed that unilateral exploration is a surgical strategy with distinct advantages in the early postoperative period. However, concerns have been raised that limited parathyroid exploration could increase the risk for recurrent pHPT during long-term follow-up. Ninety-one patients with the diagnosis of pHPT were randomized to unilateral or bilateral neck exploration. Preoperative scintigraphy and intraoperative parathyroid hormone measurement guided the unilateral exploration. Gross morphology and frozen section determined the extent of parathyroid tissue resection in the bilateral group. Follow-up was performed after 6 weeks, 1 year, and 5 years postoperatively. Seventy-one patients were available for 5-year follow-up. There were no differences in serum ionized calcium and parathyroid hormone, respectively, between patients in the unilateral and bilateral group. Overall 6 patients have been found to have persistent (n = 3) or recurrent (n = 3) pHPT; 4 patients in the unilateral group (3 of these 4 patients were bilaterally explored) and 2 patients in the bilateral group. Three of 6 failures were unexpectedly found to have multiple endocrine neoplasia mutations. One patient with solitary adenoma in the bilateral group still required vitamin D substitution 5 years after surgery. Unilateral neck exploration with intraoperative parathyroid hormone assessment provides the same long-term results as bilateral neck exploration, and is thus a valid strategy for the surgical treatment of pHPT.

Interpretation of intra-operative PTH changes in patients with multi-glandular primary hyperparathyroidism (pHPT)

The correct interpretation of intraoperative parathyroid hormone (IOPTH) levels in patients with primary hyperparathyroid patients (pHPT) with multiglandular disease (MGD) can impact the success rate of initial parathyroid exploration, but it remains an understudied topic. In all, 592 of 823 patients were explored by a single surgeon with biochemical evidence of pHPT (1997-2007) and underwent parathyroidectomy using IOPTH. We investigated the incidence of MGD in patients with an appreciable (>50%) decrease in IOPTH levels and in patients whose levels failed to normalize after single gland excision. The mean age of patients was 56.7 years, and 74% of patients were women. Thirty-one patients had PTH levels that decreased by greater than 50% from baseline 10-15 min after single gland excision, but the levels failed to normalize. Of these, 9 patients (29%) had MGD (8 double adenomas, 1 hyperplasia). The incidence of MGD in the remainder of IOPTH patients was 13.9% (78 of 561 patients). Within the subgroup of 31 patients, those with single adenomas did not differ from patients with MGD in baseline IOPTH levels and weights of first adenoma excised, although they demonstrated greater serum creatinine concentrations and a decrease in mean IOPTH. Commonly accepted decreases in IOPTH levels (>50%) for patients who undergo minimally invasive parathyroidectomy may lead to an appreciable number of missed parathyroid adenomas or hyperplastic disease.

65-jährige Patientin mit persistierender Hyperkalzämie

A 65-year old patient presented with newly diagnosed hypercalcemia and elevated parathyroid hormone levels. Exploration of parathyroid glands was performed under the diagnosis of primary hyperparathyroidism and was combined with thyreoidectomy due to concomittant multinodular goiter. However, no parathyroid adenoma was identified despite careful exploration. Therefore, the operation was terminated and an ectopic adenoma was suspected. A (99m)Tc-sestamibi scintigraphy with SPECT, neck ultrasound, neck CT scan with contrast media and selective venous sampling were performed for further localization of the adenoma. A single adenoma localized in the submandibular area of the left jaw was suspected and confirmed during surgical reexploration. Postoperatively, parathyroid hormone levels were below detection level and the patient required short-term calcium supplementation for symptomatic hypocalcemia.

Intra-Operative Parathyroid Identification Using Methylene Blue in Parathyroid Surgery

The objective of this study was to determine the value of intra-operative methylene blue (MB) during parathyroid surgery. We did a retrospective study of 473 patients after initial exploration for previously untreated symptomatic primary hyperparathyroidism. Procedural and post procedural data were collected on four groups of patients: minimally invasive parathyroidectomy with MB (n = 147), and without MB (n = 205), bilateral parathyroid exploration with intra-operative parathormone assay with MB (n = 56), and without MB (n = 65). Length of surgery was shorter for patients explored with MB (P = 0.026). For the minimally invasive parathyroidectomy group, the difference between the MB and non-MB groups was seven minutes. Twelve minutes was the difference between the MB and non-MB intra-operative parathormone assay groups. Length of stay, local complications, and correction of hypercalcemia after parathyroidectomy were not significantly affected by the use of MB. Systemic complications were lower in the MB groups. Aside from a statistically significant, but quantitatively minimal decrease in the length of surgery, no consistent benefit was identified with the use of MB for intra-operative parathyroid identification.

The Negative Sestamibi Scan: Is a Minimally Invasive Parathyroidectomy Still Possible?

Tc-99-sestamibi scanning is utilized to determine whether patients with primary hyperparathyroidism (HPT) are candidates for minimally invasive parathyroidectomy (MIP). However, if the result of this scan is negative, many surgeons recommend bilateral parathyroid exploration because of possible multi-gland disease. The objectives of this study were to determine whether patients with primary HPT and negative sestamibi scans can benefit from additional imaging studies and are still potential candidates for MIP. Between March 2001 and April 2006, 578 consecutive patients with HPT underwent parathyroidectomy by a single surgeon. Pre-operative sestamibi scans had been done in 458 (79%) of these patients, 90 (20%) of which had negative results. These patients formed our study cohort. Of the 90 patients, 60 (67%) had a single adenoma, 17 (19%) double adenomas and 13 (14%) 3- to 4-gland hyperplasias. In 74 (82%) patients, localization was further investigated with one or more studies including thallium subtraction scans (n = 30), ultrasound (n = 15) and intra-operative internal jugular venous sampling (n = 49). Additionally, the use of radio-guided techniques intra-operatively facilitated minimally invasive techniques. Of these 90 patients, 47 had positive results from preoperative studies, including 12 positive thallium, 5 positive ultrasound and 13 positive internal jugular sampling results. In addition, positive results were observed for 17 patients using radio-probe techniques in the operating room. Accordingly, minimally invasive techniques were attempted in these 47 patients; 42 (89%) had single adenomas and in 5 the technique was converted to bilateral exploration for double adenoma/hyperplasia. In the setting of a negative sestamibi, the sensitivities of thallium scans and ultrasound were 30% and 27%, respectively. The overall cure rate in the 90 patients with negative sestamibi scans was 99%. In patients with primary HPT and a negative sestamibi scan, most patients (67%) will have a single adenoma. These patients benefitted from additional localization tests, which yielded a positive result in 52% of patients. Therefore, even in the setting of a negative sestamibi scan, the majority of patients with primary HPT are still candidates for MIP.

Complications of Thyroidectomy and Parathyroidectomy in the Rural Community Hospital Setting

The objective of this study was to examine the complications encountered in a series of 150 consecutive thyroid and parathyroid procedures performed by a single surgeon in a rural community hospital setting. The goal was to demonstrate that these procedures may be performed safely and with outcomes equivalent to those of academic hospitals in major metropolitan areas despite the lack of availability of specific technologies that are being increasingly used for these procedures in tertiary care settings. Specifically, these include intraoperative parathyroid hormone measurements, intraoperative recurrent laryngeal nerve monitoring, and the use of the gamma probe for detection of parathyroid adenoma. A retrospective chart review was conducted on a series of 150 patients undergoing any thyroid or parathyroid operation by a single surgeon in a rural setting over a 4-year period. Data was reported regarding success at achieving the goal of the operation and any perioperative complications such as recurrent laryngeal nerve injury, permanent hypoparathyroidism, wound hematoma, infection, or pneumonia. One hundred thirty-one thyroid procedures were performed (71 lobectomies, 60 total or near total procedures) for a diverse range of patholological conditions: multinodular goiter, 76 (50.7%) patients, follicular adenoma, 9 (6.0%) patients, Hashimoto's thyroiditis, 13 (8.7%) patients, papillary carcinoma, 14 (9.3%) patients, follicular carcinoma, 5 (3.3%) patients, follicular variant of papillary carcinoma, 13 (8.7%) patients, and medullary carcinoma, 1 (0.7%) patient. Nineteen successful parathyroid explorations were performed for primary hyperparathyroidism. The overall incidence of recurrent nerve injury was 1.33 per cent overall (0.99% for each nerve encountered). The incidence of transient postoperative hypocalcemia was 13 per cent, with one patient suffering permanent hypoparathyroidism (0.8%). Two patients developed wound hematomas requiring evacuation. The overall complication rate with respect to recurrent laryngeal nerve injury and permanent hypoparathyroidism was consistent with or below that that in recent large series, despite the absence of specialized equipment for nerve monitoring. The success of identifying parathyroid adenoma was 100 per cent, despite the absence of intraoperative parathormone assays, and the decision not to perform radio-guided parathyroidectomy. We conclude that outcomes and complications in thyroid and parathyroid surgical procedures are largely dependent on surgeon skill and experience, and can be performed safely in the community setting by an experienced general surgeon despite the absence of advanced technology in this setting. We encourage all surgeons to continually examine their operative results with all technically demanding procedures when deciding the composition of their individual practices.

Rapid Intraoperative Parathyroid Hormone Assay in the Surgical Management of Hyperparathyroidism

Historically, successful surgical management of primary hyperparathyroidism has required bilateral exploration of the neck. By confirming complete removal of hypersecreting tissue, an intraoperative parathyroid hormone (IO-PTH) assay allows use of a more limited procedure. Our objective was to evaluate the utility of IO-PTH assay used in 32 parathyroid explorations versus conventional bilateral exploration used before the advent of IO-PTH assays. Minimally invasive parathyroidectomy (MIP) was used. Plasma samples were obtained at several intervals and were analyzed for IO-PTH by use of a rapid immunochemiluminescent assay (ICMA). Outcomes were assessed by univariate inferential testing, yielding one-tailed t-test results. The study group had a mean plasma IO-PTH level decrease of 87% at ten minutes after excision. All 32 patients who underwent MIP using IO-PTH monitoring had successful surgery. At last postoperative follow-up examination, all 32 patients were normocalcemic. There were statistically significant decreases in duration of surgery, length of hospital stay, and surgery cost. IO-PTH levels predicted the postoperative outcome for all patients studied, can provide valuable information to surgeons, and can decrease the duration of surgery and hospital stay.

PTH spikes during parathyroid exploration—a possible pitfall during PTH monitoring?

Parathyroid hormone (PTH) spikes caused by unintentional manipulation of the hypersecreting glands may lead to interpretation problems in intraoperative PTH monitoring. Their frequency and surgical consequences were evaluated. Intraoperative PTH values of 401 patients with primary hyperparathyroidism and single gland disease were analysed. Patients were divided into four groups: extensive increase (>150 pg/ml), moderate PTH increase (<150 pg/ml), no increase (+/-50 pg/ml) and decrease before excision as referred to the baseline level before skin incision. PTH was measured before and up to 25 min after removal of the enlarged gland. Twenty-two (5.5%) patients had an extensive and 36 (9%) a moderate intraoperative PTH increase. The PTH decline was prolonged to 15 min in 7 (31.8%) and to 25 min in 12 (54.5%) patients after extensive manipulation and in 9 patients (25%) each after moderate manipulation, respectively. No increase occurred in 162 (40.4%) and a decrease in 181 (45.1%) patients. The surgical approach (bilateral exploration vs open, minimally invasive parathyroidectomy) did not show a difference in the rate of PTH spikes. PTH spikes often cause a prolonged PTH decline but, when recognized, do not lead to a change in the surgical strategy.

Scandinavian quality register for thyroid and parathyroid surgery: audit of surgery for primary hyperparathyroidism

Scandinavian Quality Register for Thyroid and Parathyroid Surgery is an on-line web-based database with the aim to improve the quality of thyroid and parathyroid surgery. Preliminary data from surgery for primary hyperparathyroidism are reported here. Fifteen departments registered 806 operations, with 639 women (79.7%) and 167 men. The median age of the patients was 62 years. Approximately 95.4% of the patients had sporadic disease and first time operation was performed in 93.8% of the patients. Localization examinations were performed in 524 patients (65%); sestamibi scintigraphy in 413 patients, with a true positive adenoma localization in 64.4% and ultrasound in 293 patients with adenoma localization in 61.1%. Bilateral neck exploration was performed in 66.8%, unilateral exploration in 16.1%, and focused minimal invasive surgery in 17.1%. In 301 patients planned for limited parathyroid exploration, conversion to bilateral neck surgery occurred in 11%. The cure rate, based on short follow-up, was 91.9%. Postoperative hypocalcemia occurred in 11.4% of the patients, and was associated with reoperation, concomitant thyroid operation, and the weight of excised parathyroid tissue. Localization examinations are performed in 2/3 of the patients, but limited neck exploration was performed in only approximately 1/3 of the operations. The cure rate was lower and postoperative hypocalcemia was more frequent than expected.

Fluorescence-Guided Minimally Invasive Parathyroidectomy: A Novel Surgical Therapy for Secondary Hyperparathyroidism

Secondary hyperparathyroidism (SHPT) is a severe and frequent complication in patients with advanced chronic kidney disease, characterized by hyperplasia of all parathyroid glands and elevated serum parathyroid hormone levels. When surgery is required to prevent cardiovascular consequences, bone pain, osteoporosis, or even soft-tissue calcifications, detection of the enlarged glands often can be difficult because of their variability in number and location. A novel surgical technique, fluorescence-guided minimally invasive parathyroidectomy, may facilitate intraoperative localization of parathyroid glands. A 52-year-old woman with SHPT underwent minimally invasive videoscopic-assisted parathyroidectomy after photosensitization with aminolevulinic acid (ALA): Under special fluorescence illumination by D-Light (Karl Storz Co, Tuttlingen, Germany), bilateral neck exploration was performed. All enlarged parathyroid glands were identified because of their ALA-induced intense red fluorescence. Such surrounding structures as thyroid, lymph nodes, and soft tissue remained nonfluorescent and could be distinguished easily from parathyroid glands. Total parathyroidectomy with autotransplantation into the sternocleidoid muscle was performed. In patients with SHPT, exploration of all parathyroid glands during surgery is mandatory. However, to date, there is no convincing technical aid for the surgeon to facilitate this procedure. The ALA-induced fluorescence technique represents an innovative visual detection method for intraoperative identification of parathyroid glands. The technique serves as an additional tool requiring only moderate technical and clinical expenditure.

Partial Median Sternotomy: An Attractive Approach to Mediastinal Parathyroid Disease

Parathyroid exploration through a standard cervical approach is adequate for the resection of most mediastinal parathyroid glands. A subset of mediastinal parathyroid glands causing hyperparathyroidism, however, cannot be removed in this manner. We reviewed our experience with the use of partial median sternotomy in the treatment of these patients. Over a 14-year period, all but 10 of 937 (1.1%) consecutive patients explored for hyperparathyroidism by a single endocrine surgeon were treated by a cervical approach. Partial median sternotomy was performed in 10 cases and was successful in seven cases (70%), with conversion to a complete sternotomy being required in three cases. Six of these seven patients had failed a previous parathyroid exploration (86%), including one patient who had a previous complete sternotomy. Cure of hyperparathyroidism was achieved in all seven patients undergoing partial median sternotomy. In five patients a mediastinal parathyroid gland was removed (71%), and in one patient a parathyroid adenoma in the carotid sheath was eventually found, and the location of the hyperfunctioning parathyroid gland in one patient was never determined although the patient was cured. The mean length of hospital stay after a partial median sternotomy was 2.6 days. One patient sustained a recurrent laryngeal nerve injury at the time of a repeat cervical exploration and partial median sternotomy. Rarely, mediastinal parathyroid glands cannot be resected through a cervical approach. In these cases the use of partial median sternotomy is an attractive technique in achieving cure of hyperparathyroidism and is associated with minimal morbidity and a short length of hospital stay.

Incidence and location of ectopic abnormal parathyroid glands

Background Ectopic parathyroid glands are a cause for failed parathyroid exploration. Methods Patients with hyperparathyroidism and ectopic parathyroid glands were identified from a parathyroid database. Laboratory data, gland weights, and surgical outcomes were obtained. The locations of the ectopic glands were correlated with results of technetium-99m–sestamibi imaging. Results Of 231 patients operated on for hyperparathyroidism, 37 (16%) had ectopic parathyroid glands. Ectopic inferior glands (N = 23 [62%]) were intrathymic, n = 7 (30%); anterosuperior mediastinal, n = 5 (22%); intrathyroidal, n = 5 (22%); within the thyrothymic ligament, n = 4 (17%); and submandibular, n = 2 (9%). Ectopic superior glands (N = 14 [38%]) were in the tracheoesophageal groove, n = 6 (43%); retroesophageal, n = 3 (22%); posterosuperior mediastinal, n = 2 (14%); intrathyroidal, n = 1 (7%); in the carotid sheath, n = 1 (7%); and paraesophageal, n = 1 (7%). Sestamibi scans were true-positive in 81%, identifying 13 of 16 retrosternal glands, and false-negative in 19%. Conclusions A 16% incidence of ectopic parathyroid glands and a 100% positive predictive value of sestamibi scintigraphy underscore the importance of sestamibi imaging in patients with primary hyperparathyroidism.

Hyperthyroidism after parathyroid exploration

We hypothesized that hyperthyroidism after parathyroid exploration may be an underreported phenomenon with a course more severe than recognized previously. We examined pre- and postoperative thyroid function and outcomes in 199 consecutive patients who, since March 2000, had parathyroid exploration for primary sporadic hyperparathyroidism (HPTH). We excluded patients with prior thyroid or parathyroid surgery, preoperative thyroid medication, concurrent total thyroidectomy, or follow-up <5 months. Of 125 patients with normal preoperative serum thyroid-stimulating hormone levels, 39 (31.2%) were hyperthyroid postoperatively. Mean thyroid-stimulating hormone levels (mean +/- SD) dropped with operation from 2.0 +/- 1.1 microIU/mL to 1.2 +/- 1.4 microIU/mL (P < .0001). Nineteen patients (15%) reported symptoms 1 to 2 weeks after operation. The clinical course of hyperthyroidism typically was short, but 5 patients (4%) had symptomatic hyperthyroxinemia requiring medical therapy. Hyperthyroidism was independent of age, severity of HPTH, anatomic/pathologic features, operative time, and other measures of operative difficulty, but was associated with lithium therapy, bilateral exploration, and absence of concurrent thyroid lobectomy. Risk of hyperthyroidism may be underappreciated after routine parathyroid surgery for HPTH. Use of lithium and degree of dissection appear contributory. Patients undergoing parathyroid exploration need counseling and surveillance for hyperthyroidism, which may be reduced by minimizing the extent of parathyroid surgery.

Use of surgeon-performed office ultrasound and parathyroid fine needle aspiration for complex parathyroid localization

Background This study investigates the utility of ultrasound guided parathyroid fine needle aspiration (FNA) as a localizing technique in patients with hyperparathyroidism (HPT) undergoing re-operative neck surgery or with unusually appearing or ectopically located glands. Methods Selected patients with HPT underwent surgeon-performed FNA with ultrasound guidance. Aspirate contents were sent for cytology and parathyroid hormone (PTH) levels. All patients subsequently underwent parathyroid exploration. Results 54 patients underwent 57 ultrasound guided parathyroid biopsies. Indications for FNA included prior parathyroid (n = 29), thyroid (n = 11), or other neck surgery (n = 2), or unusual parathyroid appearance or location (n = 12). A true positive was defined as a site where the PTH aspirate was >40 pg/mL and a hypercellular gland was removed at surgery. Based on this, there were 44 true positives, 10 true negatives, and 3 false negatives; there were no false positives. The median PTH level in positive aspirates was 11,665 pg/mL. Cytology was primarily helpful in excluding other diagnoses. Conclusion Ultrasound guided FNA is a highly specific localization test for parathyroid tumors. This procedure can be successfully performed by surgeons in the office setting and is extremely valuable for directing parathyroid exploration in challenging cases. We recommend incorporating ultrasound and FNA as a pre-operative localization strategy for selected patients with HPT.

Are frozen sections useful and cost-effective in the era of intraoperative qPTH assays?

Since intraoperative quick parathormone (IOqPTH) assays are available, the role of frozen sections (FS) during parathyroid exploration has become questionable. This study compares the results of FS and IOqPTH in primary hyperparathyroidism (pHPT). FS and IOqPTH assays were performed in 102 patients who underwent bilateral neck explorations or targeted parathyroidectomy for pHPT. The operation was considered complete when both an IOqPTH drop >50% and a FS diagnosis of parathyroid adenoma were obtained. Cure was achieved in all patients. Potential pitfalls for successful operation were encountered in 14 patients with multiglandular diseases and in 4 patients who had nonparathyroid tissue removed. FS correctly predicted the definitive histologic diagnosis with an accuracy of 81%. FS failures potentially misguided the operative therapy in 19% (14 insufficient explorations and 5 unnecessarily prolonged explorations), while IOqPTH identified all potential pitfalls and correctly guided the operative strategy, suggesting further exploration, in 100% of cases (P < .0001). After bilateral neck exploration, FS and IOqPTH correctly guided operative strategy in 86% and 100% of cases, respectively (P < .05), but both techniques were never indispensable, because potential pitfalls were already evident by macroscopic intraoperative appearance. The turnaround time and costs for IOqPTH were lower (P < .001). The role of FS should be reconsidered, since it can misguide the operative strategy. IOqPTH is indispensable for a focused approach and, although unnecessary in bilateral neck exploration, is more useful and cost-effective than FS.

Intraoperative parathyroid hormone testing improves cure rates in patients undergoing minimally invasive parathyroidectomy

Intraoperative parathyroid hormone (iPTH) testing often is used during minimally invasive parathyroidectomy for primary hyperparathyroidism (1 degrees HPT). However, several investigators report that these assays are not cost effective and do not improve outcomes significantly. To determine the impact of iPTH testing on the outcomes of patients with 1 degrees HPT, we reviewed our experience. From January 1990 to June 2004, there were 345 consecutive patients with 1 degrees HPT and positive localization studies for a single parathyroid adenoma who were candidates for minimally invasive parathyroidectomy. Group 1 patients (n = 157) underwent parathyroid exploration without iPTH testing and group 2 patients (n = 188) had an operation with iPTH testing. Of the group 1 patients, 15 (10%) still were hypercalcemic postoperatively owing to additional unidentified hyperfunctioning parathyroid glands. In contrast, among 188 group 2 patients, 170 (90%) had resection of a single parathyroid adenoma, a greater than 50% decrease in iPTH levels, and were cured. The remaining 18 (10%) patients did not have an adequate reduction in iPTH levels and underwent bilateral neck exploration with resection of additional parathyroids. Of these 18 patients, 9 had double adenomas and 9 had 3- or 4-gland hyperplasia. Importantly, all patients in group 2 were cured. iPTH testing improves cure rates in patients undergoing minimally invasive parathyroidectomy. iPTH testing allowed intraoperative recognition and resection of additional hyperfunctioning parathyroids missed by preoperative imaging studies. Consequently, we strongly advocate the routine use of iPTH testing in patients who undergo minimally invasive parathyroidectomy for 1 degrees HPT.