Allan Siperstein - Academia.edu (original) (raw)

Papers by Allan Siperstein

Research paper thumbnail of Perioperative inefficiencies and distractions in an endocrine surgical service

Perioperative Care and Operating Room Management, 2016

Research paper thumbnail of Predictors of recurrence in pheochromocytoma

Surgery, 2014

Background. The recurrence rate of pheochromocytoma after adrenalectomy is 6.5-16.5%. This study ... more Background. The recurrence rate of pheochromocytoma after adrenalectomy is 6.5-16.5%. This study aims to identify predictors of recurrence and optimal biochemical testing and imaging for detecting the recurrence of pheochromocytoma. Methods. In this retrospective study we reviewed all patients who underwent adrenalectomy for pheochromocytoma during a 14-year period at a single institution. Results. One hundred thirty-five patients had adrenalectomy for pheochromocytoma. Eight patients (6%) developed recurrent disease. The median time from initial operation to diagnosis of recurrence was 35 months. On multivariate analysis, tumor size >5 cm was an independent predictor of recurrence. One patient with recurrence died, 4 had stable disease, 2 had progression of disease, and 1 was cured. Recurrence was diagnosed by increases in plasma and/or urinary metanephrines and positive imaging in 6 patients (75%), and by positive imaging and normal biochemical levels in 2 patients (25%). Conclusion. Patients with large tumors (>5 cm) should be followed vigilantly for recurrence. Because 25% of patients with recurrence had normal biochemical levels, we recommend routine imaging and testing of plasma or urinary metanephrines for prompt diagnosis of recurrence. (Surgery 2014;156:1523-8.)

Research paper thumbnail of Perioperative inefficiencies and distractions in an endocrine surgical service

Perioperative Care and Operating Room Management, 2016

Research paper thumbnail of Expanding the net: The re-evaluation of the multidimensional nomogram calculating the upper limit of normal PTH (maxPTH) in the setting of secondary hyperparathyroidism and the development of the MultIdimensional Predictive hyperparaTHyroid model (Mi-PTH)

Surgery, Jan 31, 2015

The multidimensional nomogram calculating the upper limit of normal PTH (maxPTH) model identifies... more The multidimensional nomogram calculating the upper limit of normal PTH (maxPTH) model identifies a personalized upper limit of normal parathyroid hormone (PTH) and successfully predicts classical primary hyperparathyroidism (PHP). We aimed to assess whether maxPTH can distinguish normocalcemic PHP (NCPHP) from secondary hyperparathyroidism (SHP), including subjects who underwent bariatric surgery (BrS). A total of 172 subjects with 359 complete datasets of serum calcium (Ca), 25-OH vitamin D, and intact PTH from Oregon were analyzed: 123 subjects (212 datasets) with PHP and 47 (143) with SHP, including 28 (100) with previous BrS. An improved prediction model, MultIdimensional evaluation for Primary hyperparaTHyroidism (Mi-PTH), was created with the same variables as maxPTH by the use of a combined cohort (995 subjects) including participants from previous studies. In the Oregon cohort, maxPTH's sensitivity was 100% for classical PHP and 89% for NCPHP, but only 50% for normohorm...

Research paper thumbnail of Mapping endocrine surgery: Workforce analysis from the last six decades

Surgery, 2015

We analyzed the demographics of high-volume surgeons (HVS) for endocrine operations. We character... more We analyzed the demographics of high-volume surgeons (HVS) for endocrine operations. We characterized HVS by region, specialty, gender, teaching-affiliation, American Association of Endocrine Surgeons (AAES) membership, and decade they entered practice. Providers were general surgeons (GS) and otolaryngologists (ENT); fellowship trained (FT) or not FT (NFT). We identified 395 HVS in 47 states entering practice between 1958 and 2011. Sixty-eight percent were GS, 35% were FT, and 35% were AAES members. GS, FT surgeons, and endocrine surgery FT surgeons (ES) performed more operations per surgeon. More FT surgeons were in Northeast, West (W), and Midwest than Southeast (SE) and Southwest (SW; P < .0001). More teaching surgeons and AAES members were in the Northeast and Midwest than SE, W, and SW (P < .0001). FT-GS increased over decades (P < .0001) but not FT-ENT (P = .3). Representation of ES, AAES members, and females increased over decades (P < .0001). The workforce for endocrine operations displayed increased representation of GS, FT surgeons, and women, correlating with the profile of recent AAES fellowship graduates. More insight is needed to understand why most HVS were not AAES members. Regional disparities can guide the placement of endocrine surgeons into both academic and community practices, increasing trainee exposure and patient access to specialty care.

Research paper thumbnail of Diagnostic accuracy of circulating thyrotropin receptor messenger RNA combined with neck ultrasonography in patients with Bethesda III–V thyroid cytology

Surgery, 2015

The aim of this study was to analyze the usefulness of thyrotropin receptor messenger RNA (TSHR-m... more The aim of this study was to analyze the usefulness of thyrotropin receptor messenger RNA (TSHR-mRNA) combined with neck ultrasonography (US) in the management of thyroid nodules with Bethesda III-V cytology. Cytology slides of patients with a preoperative fine needle aspiration (FNA) and TSHR-mRNA who underwent thyroidectomy between 2002 and 2011 were recategorized based on the Bethesda classification. Results of thyroid FNA, TSHR-mRNA, and US were compared with the final pathology. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. There were 12 patients with Bethesda III, 112 with Bethesda IV, and 58 with Bethesda V cytology. The sensitivity of TSHR-mRNA in predicting cancer was 33%, 65%, and 79 %, and specificity was 67%, 66%, and 71%, for Bethesda III, IV, and V categories, respectively. For the same categories, the PPV of TSHR-mRNA was 25%, 33%, and 79%, respectively; whereas the NPV was 75%, 88%, and 71%, respectively. The addition of neck US to TSHR-mRNA increased the NPV to 100% for Bethesda III, and 86%, for Bethesda IV, and 82% for Bethesda V disease. This study documents the potential usefulness of TSHR-mRNA for thyroid nodules with Bethesda III-V FNA categories. TSHR-mRNA may be used to exclude Bethesda IV disease. A large sample analysis is needed to determine its accuracy for Bethesda category III nodules.

Research paper thumbnail of The utility of peripheral thyrotropin receptor mRNA in the management of differentiated thyroid cancer

Surgery, 2015

Background. Our aim was to analyze the utility of peripheral thyrotropin receptor (TSHR) messenge... more Background. Our aim was to analyze the utility of peripheral thyrotropin receptor (TSHR) messenger RNA (mRNA) in predicting and detecting the recurrence of differentiated thyroid cancer. Methods. Peripheral blood TSHR-mRNA was obtained in 103 patients before and after total thyroidectomy. An analysis was performed to correlate peripheral blood TSHR-mRNA concentration with oncologic outcomes. Results. Tumor types were papillary (n = 92), follicular (n = 9) and H€ urthle cell (n = 2) cancer. Preoperative TSHR-mRNA was 1.02ng/mgin851.02 ng/mg in 85% (88/103). On follow-up (median 48 months), 10 patients (10 %) developed recurrence. Recurrence rate in patients with a preoperative TSHR-mRNA 1.02ng/mgin85 1.02 ng/mg was 11% versus 0% in those with a lesser concentration. TSHR-mRNA correctly diagnosed 7 (70%) of 10 recurrences. Of 19 patients with positive thyroglobulin (Tg) antibodies, TSHR-mRNA confirmed disease-free status in 12 (63%) and recurrence in 1 (5%). For Tg, TSHR-mRNA and whole-body radioactive iodine scan, sensitivity was 70%, 70%, and 75%; specificity 94%, 76%, 97%; PPV 54%, 24%, and 67%; and NPV 97%, 96%, and 98%, respectively, in detecting recurrent disease.

Research paper thumbnail of The Changing Presentation of Hyperparathyroidism Over 3 Decades

To analyze changes in the presentation of primary hyperparathyroidism over the last 3 decades. Re... more To analyze changes in the presentation of primary hyperparathyroidism over the last 3 decades. Retrospective review. Tertiary referral center. Three hundred patients undergoing parathyroidectomy for primary hyperparathyroidism, 100 each in the years 1985, 1995, and 2005. Analysis was performed based on patient age, sex, preoperative calcium value, duration of hypercalcemia, symptoms at presentation, and reason for surgical referral. Patients from the years 1985, 1995, and 2005 were similar in age and sex. Mean (SEM) preoperative calcium values decreased from 11.8 (0.1) mg/dL in 1985 to 11.2 (0.1) mg/dL in 2005 (P < .001) (to convert milligrams per deciliter to millimoles per liter, multiply by 0.25). The proportion of patients with preoperative calcium values less than 11.0 mg/dL steadily rose from 10% in 1985 to 43% in 2005 (P < .001). The mean (SEM) time from diagnosis of hypercalcemia until surgical referral decreased from 2.5 (0.4) years in 1985 to 1.6 (0.2) years in 2005 (P = .08). The primary reason for referral has shifted toward osteoporosis (20% in 2005 vs 7% in 1985; P = .03). The percentage of patients diagnosed with osteoporosis or osteopenia preoperatively increased from 10% in 1985 to 44% in 2005 (P < .001), and the recognition of these conditions in men increased from 3% to 26% (P = .10). Over the last 3 decades, increased awareness of hyperparathyroidism and its consequences as well as the institution of screening bone densitometry have changed the profile of patients who are referred for surgery. Patients are being referred sooner, with a lesser degree of hypercalcemia and greater recognition of osteoporosis.

Research paper thumbnail of A critical analysis of intraoperative time utilization in laparoscopic adrenalectomy

Surgical endoscopy, 2002

Time and efficiency analysis is a technique common in industry that is being applied to surgical ... more Time and efficiency analysis is a technique common in industry that is being applied to surgical procedures. The aim of this study is to analyze the time spent performing the component parts of laparoscopic adrenalectomy by both the lateral transabdominal and the posterior retroperitoneal approaches. Operational videotapes of 33 patients undergoing laparoscopic adrenalectomy (12 lateral, 21 posterior) were reviewed. The operation was divided into six steps: trocar entry, laparoscopic ultrasonography, exposure of the adrenal gland, dissection of the adrenal, extraction of specimen, and irrigation-aspiration. Time spent for each step and the relation with age, gender, body mass index (BMI), tumor size, side, and histology were assessed using Student's t-test, Pearson correlation, and regression analysis. Although tumor size was larger in the lateral compared to the posterior approach (5.5 vs 2.5 cm, p < 0.001), there was no difference between the groups regarding total operatin...

Research paper thumbnail of Line-associated thrombosis as the major cause of hospital-acquired deep vein thromboses: an analysis from National Surgical Quality Improvement Program data and a call to reassess prophylaxis strategies

American journal of surgery, 2014

Quality improvement has mitigated the occurrence of postoperative deep vein thromboses (DVTs); ho... more Quality improvement has mitigated the occurrence of postoperative deep vein thromboses (DVTs); however, despite adherence to protocols, they continue to occur. This study aimed to characterize their rate and distribution at our institution, and appropriate use of thromboprophylaxis. Local American College of Surgeons National Surgical Quality Improvement Program data were queried for general surgery cases complicated by DVT from 2009 to 2011. Medical records were evaluated to ascertain the following: classify DVTs by site, ascertain if appropriate prophylactic measures were instituted, evaluate treatment instituted, evaluate the occurrence of a PE if the DVT was line-associated, and if so, the indication for the central line. Of 1,857 patients, 39 had postoperative DVTs (2.1%). Fourteen lower-extremity (35.9%) DVTs, 4 central (10%) DVTs, and 21 upper-extremity (53.8%) DVTs (UEDVTs) were captured. All but 2 had appropriate thromboprophylaxis. All but one UEDVT was line-associated. Di...

Research paper thumbnail of The utility of intraoperative ultrasound in modified radical neck dissection: a pilot study

Surgical innovation, 2014

Although the value of surgeon-performed neck ultrasound (SPUS) for thyroid nodules has been valid... more Although the value of surgeon-performed neck ultrasound (SPUS) for thyroid nodules has been validated, the utility of intraoperative ultrasound (US) in modified radical neck dissection (MRND) has not been reported in the literature. The aim of this study was to analyze the utility of intraoperative SPUS in assessing the completeness of MRND for thyroid cancer. Between 2007 and 2011, a total of 25 patients underwent MRND by 1 surgeon for thyroid cancer. All patients underwent intraoperative SPUS, which was repeated at the end of the neck dissection (completion US) to look for missed lymph nodes (LNs). There were 10 male and 15 female patients. Pathology included 23 papillary and 2 medullary carcinomas. The number of LNs removed per case was 23 ± 2, and the number of positive was LNs 5 ± 1. In 4 (16%) cases, intraoperative US detected 7 residual LNs, which would have been missed, if completion US were not done. These missed LNs were located in low-level IV (3 nodes), high-level II (2 ...

Research paper thumbnail of Predicting the Success of Limited Exploration for Primary Hyperparathyroidism Using Ultrasound, Sestamibi, and Intraoperative Parathyroid Hormone

Transactions of the ... Meeting of the American Surgical Association, 2008

The aim of this study was to determine the success of limited neck exploration (LE) for primary h... more The aim of this study was to determine the success of limited neck exploration (LE) for primary hyperparathyroidism (1 degrees HPT). Between 1999 and 2007, 1407 patients with hyperparathyroidism underwent bilateral neck exploration (BE). Of these, 1158 patients with first-time sporadic 1 degrees HPT were analyzed prospectively. Based on surgeon-performed ultrasound (US) and sestamibi scan (MIBI), LE was initially performed. Regardless of results, BE followed to identify the presence of additional parathyroid pathology. Of 1158 patients, 242 (21%) were found to require concomitant thyroid surgery thus excluding LE. Of the remaining 916 patients, a single abnormal gland was identified on MIBI in 682 (74%), US in 731 (80%), and concordance of both in 588 (64%). Unsuspected multiglandular disease (MGD) was identified at BE in 22%, 22%, and 20% of patients, respectively. Adding intraoperative parathyroid hormone sampling (IOPTH) further reduced the rate of unsuspected MGD to 16%, 17%, and 16%. Overall, IOPTH correctly predicted MGD in only 22%. Neither concomitant nonsurgical thyroid disease nor more stringent selection criteria (preop Ca&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;11 mg/dL and PTH&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;120 pg/dL) altered success rates. In patients with MGD, a subsequent gland identified was larger than the index gland in 23%. Ninety-eight percent of BE patients were cured of 1 degrees HPT. This is the largest study to evaluate the prevalence of additional parathyroid pathology in patients who are candidates for LE. Limitations in localizing studies and IOPTH fail to identify MGD in at least 16% of patients, risking future recurrence.

Research paper thumbnail of Ultrasonography for the endocrine surgeon: A valuable clinical tool that enhances diagnostic and therapeutic outcomes

Surgery, 2005

Surgeon-performed ultrasonography (U/S) has revolutionized many subspecialties by broadening the ... more Surgeon-performed ultrasonography (U/S) has revolutionized many subspecialties by broadening the diagnostic and interventional scope of practice. We report our experience on the impact of surgeon-performed U/S in an endocrine surgery practice. Prospectively maintained records of patients from November 1999 to November 2004 were reviewed to establish patterns and outcomes of U/S practice. Surgeon-performed neck U/S was done routinely at the initial clinic visit and incorporated into resident/fellow education. A total of 5703 U/S were performed on endocrine patients with thyroid 42%, parathyroid 57%, and adrenal 1% disorders. Diagnostic fine-needle aspiration biopsy (FNA) was achieved with low sampling errors (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;7%). When U/S identified thyroid nodules coexisting with hyperparathyroidism, preoperative FNA correctly established benign thyroid diagnosis and minimized need for thyroidectomy. U/S successfully imaged abnormal parathyroid glands when (99)Tc-sestamibi scans were negative. U/S data significantly changed treatment plans in nearly two thirds of thyroid cancer patients. Surgical residents readily mastered essential U/S skills. Surgeon-performed U/S is a highly specific tool for identification of endocrine disease in the neck. It is learned readily and performed accurately, and functions as an informative extension of physical examination. Because it substantially benefits patient care and impacts surgical decision making, neck U/S is recommended highly as a valuable adjunct to endocrine surgical practice.

Research paper thumbnail of Robotic Transaxillary Thyroidectomy: Report of 2 Cases and Description of the Technique

Surgical Laparoscopy, Endoscopy & Percutaneous Techniques, 2010

Various techniques for minimally invasive thyroid surgery have been described over the last decad... more Various techniques for minimally invasive thyroid surgery have been described over the last decade. These techniques have significant limitations owing to 2-dimensional view and awkward endoscopic instrumentation. Robotic surgical technology was developed to overcome these limitations. In this case report, we are describing our first 2 thyroid procedures using this technology: a total thyroidectomy in a 66-year old, and a thyroid lobectomy in a 43-year old. We found that robotic resection avoids a neck scar and offers quality 3-dimensional vision with dexterity similar to the human hand.

Research paper thumbnail of Prospective evaluation of sestamibi scan, ultrasonography, and rapid PTH to predict the success of limited exploration for sporadic primary hyperparathyroidism

Surgery, 2004

The aim of this study was to determine the ability of localizing studies and rapid intraoperative... more The aim of this study was to determine the ability of localizing studies and rapid intraoperative parathyroid hormone (PTH) to predict the success of a limited approach in patients who then underwent bilateral exploration. Preoperative sestamibi-iodine subtraction scan and neck ultrasonography (US) were used to direct a focal (1-gland) and unilateral (1-sided) parathyroid exploration by using rapid intraoperative PTH determinations in 350 patients with sporadic primary hyperparathyroidism. Regardless of the findings, the contralateral side was then explored. A single gland was predicted by sestamibi in 290 patients (83%), US in 298 patients (85%), and concordance of both in 205 patients (59%). Unilateral parathyroid exploration, directed by these studies, would correctly identify single-gland disease in only 68%, 74%, and 79%, respectively. The addition of intraoperative PTH would increase the success rate to 73%, 77%, and 82%, respectively. The finding of 2 normal or 2 abnormal glands on 1 side would force bilateral exploration, and additional unsuspected pathology was found in 13%, 13%, and 9%, respectively. This failure rate would increase to 21%, 18%, and 15%, respectively, if the analysis assumed a focal rather than unilateral approach to the initial exploration. Even in patients with concordant sestamibi and US scans, and an appropriate PTH drop, additional abnormal parathyroid glands were found on complete exploration in 15%. A bilateral approach offers the best opportunity for the long-term cure of primary hyperparathyroidism.

Research paper thumbnail of The Impact of Office Neck Ultrasonography on Reducing Unnecessary Thyroid Surgery in Patients Undergoing Parathyroidectomy

Thyroid, 2005

Some have suggested that thyroid disease is even more prevalent among patients with hyperparathyr... more Some have suggested that thyroid disease is even more prevalent among patients with hyperparathyroidism (HPT) than in the general population. We sought to define the incidence and optimal management strategies of thyroid disease in patients undergoing surgery for HPT. Clinical characteristics were reviewed for 1200 consecutive HPT patients treated at two endocrine surgery referral centers from 1992-2003. Both centers practice bilateral neck exploration, and one routinely obtains preoperative neck ultrasound (US) performed by surgeons. Forty percent (477/1195) of HPT patients had coexisting thyroid disease, whether identified at parathyroidectomy (39%; 327/845) or by US (43%; 150/350). Colloid nodules/goiters accounted for nearly half of thyroid pathology, followed by follicular adenomas, papillary cancer, thyroiditis, and intrathyroidal parathyroids. Thyroid malignancy was found in 4.6% of HPT patients versus less than 1% in autopsy reports. Thyroid pathology was similar among single adenomas, multigland, and renal HPT. Unexpected thyroid disease first encountered at parathyroidectomy required partial or total thyroidectomy in 30% (257/845). US-detected thyroid nodules prompted fine-needle biopsy in 20%, which was cost effective in limiting concomitant thyroid surgery to fewer patients (6%; 21/350). Overall low incidence (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.5%) of persistent/recurrent HPT, nerve injury, and neck hematoma was unaffected by thyroid abnormalities. The high prevalence of thyroid disease, especially malignancies, among HPT patients mandates vigilant diagnosis and preparation for possible simultaneous parathyroid-thyroid surgery. Without appropriate preoperative screening, focal explorations for HPT may be prone to delayed diagnosis of thyroid tumors. Ultrasound performed by surgeons or endocrinologists preoperatively is an excellent diagnostic tool and minimizes unnecessary thyroidectomy in patients with subclinical thyroid disease.

Research paper thumbnail of A new risk stratification algorithm for the management of patients with adrenal incidentalomas

Surgery, 2014

Although adrenal incidentalomas (AI) are detected in ≤5% of patients undergoing chest and abdomin... more Although adrenal incidentalomas (AI) are detected in ≤5% of patients undergoing chest and abdominal computed tomography (CT), their management is challenging. The current guidelines include recommendations from the National Institutes of Health, the American Association of Endocrine Surgeons (AAES), and the American Association for Cancer Education (AACE). The aim of this study was to develop a new risk stratification model and compare its performance against the existing guidelines for managing AI. A risk stratification model was designed by assigning points for adrenal size (1, 2, or 3 points for tumors &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;4, 4-6, or &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;6 cm, respectively) and Hounsfield unit (HU) density on noncontrast CT (1, 2, or 3 points for HU &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;10, 10-20, or &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;20, respectively). This model was applied retrospectively to 157 patients with AI managed in an endocrine surgery clinic to assign a score to each tumor. The utility of this model versus the AAES/AACE guidelines was assessed. Of the 157 patients, 54 (34%), had tumors &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;4 cm with HU &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;10 (a score of 2). One third of these were hormonally active on biochemical workup and underwent adrenalectomy. The remaining two thirds were nonsecretory lesions and have been followed conservatively with annual testing. In 103 patients (66%), the adrenal mass was &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;4 cm and/or had indeterminate features on noncontrast CT (HU &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;10, irregular borders, heterogeneity), and adrenalectomy was performed after hormonal evaluation was completed (10 were hormonally active on biochemical testing). Seven of these patients (7%) had adrenocortical cancer on final pathology with tumor size &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;4 cm in 0, 4-6 cm in 1, and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;6 cm in 5 patients. Of the hormonally inactive patients, 32% had a score of 3, 38% 4, and 30% 5 or 6. The incidence of adrenocortical cancer in these subgroups was 0, 0, and 25%, respectively. This study shows that an algorithm that utilizes the hormonal activity at the first decision step followed by a consolidated risk stratification, based on tumor size and HU density, has a potential to spare a substantial number of patients from unnecessary &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;diagnostic&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; surgery for AI.

Research paper thumbnail of An analysis of whether surgeon-performed neck ultrasound can be used as the main localizing study in primary hyperparathyroidism

Surgery, 2014

Tc-99 sestamibi (MIBI) scan is the imaging study most frequently used in primary hyperparathyroid... more Tc-99 sestamibi (MIBI) scan is the imaging study most frequently used in primary hyperparathyroidism (PHP). Transcutaneous cervical ultrasonography (US) is the other modality used for preoperative localization. The aim of this study was to determine whether surgeon-performed neck US can be used as the primary localizing study in PHP. This was a prospective study of 1,000 consecutive patients with first-time, sporadic PHP who underwent parathyroidectomy at a tertiary academic center. All patients had surgeon-performed neck US and MIBI before bilateral neck exploration. The findings at exploration were 72% single adenoma, 15% double adenoma, and 13% hyperplasia. When US suggested single-gland disease (n = 842), MIBI was concordant in 82.5%, discordant and false in 8%, negative in 7%, and discordant but correct in 2.5%. When US suggested multigland disease (n = 68), MIBI was concordant in 47%, discordant and false in 41%, and negative in 12%. When US was negative (n = 90), MIBI was positive and correct in 43%, negative in 31%, and positive but false in 26%. Surgeon-performed neck US identified unrecognized thyroid nodules in 326 patients (33%), which led to fine-needle aspiration biopsy in 161 (49%) patients and thyroid surgery in 103 (32%) patients, with a final diagnosis of thyroid cancer in 24 (7%) patients. Our results show that MIBI provides additional useful information in only a minority of patients with a positive US in PHP. Nevertheless, MIBI benefits about half of patients with a negative US. Because one-third of this patient population has unrecognized thyroid nodules as well, we propose that the most cost-effective algorithm would be to do US first and reserve MIBI for US-negative cases.

Research paper thumbnail of Laparoscopic ultrasonography and biopsy of hepatic tumors in 310 patients

The American Journal of Surgery, 2004

Background: Laparoscopic ultrasonography is increasingly being recognized as an important tool in... more Background: Laparoscopic ultrasonography is increasingly being recognized as an important tool in the evaluation of patients with possible hepatic tumors. The aim of this paper is to describe the technical aspects of imaging and biopsy based on our experience in 310 patients with 1,080 primary and metastatic liver tumors within a 6.5-year period. Methods: A 10-mm rigid or flexible, 7.5 MHz linear, side-viewing laparoscopic ultrasonography probe was used for imaging, and an 18G spring-loaded core biopsy gun was used for tissue diagnosis. Results: There were no complications. The entire liver was imaged using a right subcostal port. Using a free-hand technique, the needle was best targeted into the lesion when inserted parallel to the plane of the transducer. The rigid transducer was found to be more convenient to guide needle placement. Conclusions: The use of this minimally invasive technique avoids laparotomy in many patients undergoing staging of malignancy and also offers increased sensitivity for tumor detection compared with conventional imaging modalities.

Research paper thumbnail of Predictors of recurrence in pheochromocytoma

Surgery, 2014

Background. The recurrence rate of pheochromocytoma after adrenalectomy is 6.5-16.5%. This study ... more Background. The recurrence rate of pheochromocytoma after adrenalectomy is 6.5-16.5%. This study aims to identify predictors of recurrence and optimal biochemical testing and imaging for detecting the recurrence of pheochromocytoma. Methods. In this retrospective study we reviewed all patients who underwent adrenalectomy for pheochromocytoma during a 14-year period at a single institution. Results. One hundred thirty-five patients had adrenalectomy for pheochromocytoma. Eight patients (6%) developed recurrent disease. The median time from initial operation to diagnosis of recurrence was 35 months. On multivariate analysis, tumor size >5 cm was an independent predictor of recurrence. One patient with recurrence died, 4 had stable disease, 2 had progression of disease, and 1 was cured.

Research paper thumbnail of Perioperative inefficiencies and distractions in an endocrine surgical service

Perioperative Care and Operating Room Management, 2016

Research paper thumbnail of Predictors of recurrence in pheochromocytoma

Surgery, 2014

Background. The recurrence rate of pheochromocytoma after adrenalectomy is 6.5-16.5%. This study ... more Background. The recurrence rate of pheochromocytoma after adrenalectomy is 6.5-16.5%. This study aims to identify predictors of recurrence and optimal biochemical testing and imaging for detecting the recurrence of pheochromocytoma. Methods. In this retrospective study we reviewed all patients who underwent adrenalectomy for pheochromocytoma during a 14-year period at a single institution. Results. One hundred thirty-five patients had adrenalectomy for pheochromocytoma. Eight patients (6%) developed recurrent disease. The median time from initial operation to diagnosis of recurrence was 35 months. On multivariate analysis, tumor size >5 cm was an independent predictor of recurrence. One patient with recurrence died, 4 had stable disease, 2 had progression of disease, and 1 was cured. Recurrence was diagnosed by increases in plasma and/or urinary metanephrines and positive imaging in 6 patients (75%), and by positive imaging and normal biochemical levels in 2 patients (25%). Conclusion. Patients with large tumors (>5 cm) should be followed vigilantly for recurrence. Because 25% of patients with recurrence had normal biochemical levels, we recommend routine imaging and testing of plasma or urinary metanephrines for prompt diagnosis of recurrence. (Surgery 2014;156:1523-8.)

Research paper thumbnail of Perioperative inefficiencies and distractions in an endocrine surgical service

Perioperative Care and Operating Room Management, 2016

Research paper thumbnail of Expanding the net: The re-evaluation of the multidimensional nomogram calculating the upper limit of normal PTH (maxPTH) in the setting of secondary hyperparathyroidism and the development of the MultIdimensional Predictive hyperparaTHyroid model (Mi-PTH)

Surgery, Jan 31, 2015

The multidimensional nomogram calculating the upper limit of normal PTH (maxPTH) model identifies... more The multidimensional nomogram calculating the upper limit of normal PTH (maxPTH) model identifies a personalized upper limit of normal parathyroid hormone (PTH) and successfully predicts classical primary hyperparathyroidism (PHP). We aimed to assess whether maxPTH can distinguish normocalcemic PHP (NCPHP) from secondary hyperparathyroidism (SHP), including subjects who underwent bariatric surgery (BrS). A total of 172 subjects with 359 complete datasets of serum calcium (Ca), 25-OH vitamin D, and intact PTH from Oregon were analyzed: 123 subjects (212 datasets) with PHP and 47 (143) with SHP, including 28 (100) with previous BrS. An improved prediction model, MultIdimensional evaluation for Primary hyperparaTHyroidism (Mi-PTH), was created with the same variables as maxPTH by the use of a combined cohort (995 subjects) including participants from previous studies. In the Oregon cohort, maxPTH's sensitivity was 100% for classical PHP and 89% for NCPHP, but only 50% for normohorm...

Research paper thumbnail of Mapping endocrine surgery: Workforce analysis from the last six decades

Surgery, 2015

We analyzed the demographics of high-volume surgeons (HVS) for endocrine operations. We character... more We analyzed the demographics of high-volume surgeons (HVS) for endocrine operations. We characterized HVS by region, specialty, gender, teaching-affiliation, American Association of Endocrine Surgeons (AAES) membership, and decade they entered practice. Providers were general surgeons (GS) and otolaryngologists (ENT); fellowship trained (FT) or not FT (NFT). We identified 395 HVS in 47 states entering practice between 1958 and 2011. Sixty-eight percent were GS, 35% were FT, and 35% were AAES members. GS, FT surgeons, and endocrine surgery FT surgeons (ES) performed more operations per surgeon. More FT surgeons were in Northeast, West (W), and Midwest than Southeast (SE) and Southwest (SW; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .0001). More teaching surgeons and AAES members were in the Northeast and Midwest than SE, W, and SW (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .0001). FT-GS increased over decades (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .0001) but not FT-ENT (P = .3). Representation of ES, AAES members, and females increased over decades (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .0001). The workforce for endocrine operations displayed increased representation of GS, FT surgeons, and women, correlating with the profile of recent AAES fellowship graduates. More insight is needed to understand why most HVS were not AAES members. Regional disparities can guide the placement of endocrine surgeons into both academic and community practices, increasing trainee exposure and patient access to specialty care.

Research paper thumbnail of Diagnostic accuracy of circulating thyrotropin receptor messenger RNA combined with neck ultrasonography in patients with Bethesda III–V thyroid cytology

Surgery, 2015

The aim of this study was to analyze the usefulness of thyrotropin receptor messenger RNA (TSHR-m... more The aim of this study was to analyze the usefulness of thyrotropin receptor messenger RNA (TSHR-mRNA) combined with neck ultrasonography (US) in the management of thyroid nodules with Bethesda III-V cytology. Cytology slides of patients with a preoperative fine needle aspiration (FNA) and TSHR-mRNA who underwent thyroidectomy between 2002 and 2011 were recategorized based on the Bethesda classification. Results of thyroid FNA, TSHR-mRNA, and US were compared with the final pathology. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. There were 12 patients with Bethesda III, 112 with Bethesda IV, and 58 with Bethesda V cytology. The sensitivity of TSHR-mRNA in predicting cancer was 33%, 65%, and 79 %, and specificity was 67%, 66%, and 71%, for Bethesda III, IV, and V categories, respectively. For the same categories, the PPV of TSHR-mRNA was 25%, 33%, and 79%, respectively; whereas the NPV was 75%, 88%, and 71%, respectively. The addition of neck US to TSHR-mRNA increased the NPV to 100% for Bethesda III, and 86%, for Bethesda IV, and 82% for Bethesda V disease. This study documents the potential usefulness of TSHR-mRNA for thyroid nodules with Bethesda III-V FNA categories. TSHR-mRNA may be used to exclude Bethesda IV disease. A large sample analysis is needed to determine its accuracy for Bethesda category III nodules.

Research paper thumbnail of The utility of peripheral thyrotropin receptor mRNA in the management of differentiated thyroid cancer

Surgery, 2015

Background. Our aim was to analyze the utility of peripheral thyrotropin receptor (TSHR) messenge... more Background. Our aim was to analyze the utility of peripheral thyrotropin receptor (TSHR) messenger RNA (mRNA) in predicting and detecting the recurrence of differentiated thyroid cancer. Methods. Peripheral blood TSHR-mRNA was obtained in 103 patients before and after total thyroidectomy. An analysis was performed to correlate peripheral blood TSHR-mRNA concentration with oncologic outcomes. Results. Tumor types were papillary (n = 92), follicular (n = 9) and H€ urthle cell (n = 2) cancer. Preoperative TSHR-mRNA was 1.02ng/mgin851.02 ng/mg in 85% (88/103). On follow-up (median 48 months), 10 patients (10 %) developed recurrence. Recurrence rate in patients with a preoperative TSHR-mRNA 1.02ng/mgin85 1.02 ng/mg was 11% versus 0% in those with a lesser concentration. TSHR-mRNA correctly diagnosed 7 (70%) of 10 recurrences. Of 19 patients with positive thyroglobulin (Tg) antibodies, TSHR-mRNA confirmed disease-free status in 12 (63%) and recurrence in 1 (5%). For Tg, TSHR-mRNA and whole-body radioactive iodine scan, sensitivity was 70%, 70%, and 75%; specificity 94%, 76%, 97%; PPV 54%, 24%, and 67%; and NPV 97%, 96%, and 98%, respectively, in detecting recurrent disease.

Research paper thumbnail of The Changing Presentation of Hyperparathyroidism Over 3 Decades

To analyze changes in the presentation of primary hyperparathyroidism over the last 3 decades. Re... more To analyze changes in the presentation of primary hyperparathyroidism over the last 3 decades. Retrospective review. Tertiary referral center. Three hundred patients undergoing parathyroidectomy for primary hyperparathyroidism, 100 each in the years 1985, 1995, and 2005. Analysis was performed based on patient age, sex, preoperative calcium value, duration of hypercalcemia, symptoms at presentation, and reason for surgical referral. Patients from the years 1985, 1995, and 2005 were similar in age and sex. Mean (SEM) preoperative calcium values decreased from 11.8 (0.1) mg/dL in 1985 to 11.2 (0.1) mg/dL in 2005 (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001) (to convert milligrams per deciliter to millimoles per liter, multiply by 0.25). The proportion of patients with preoperative calcium values less than 11.0 mg/dL steadily rose from 10% in 1985 to 43% in 2005 (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). The mean (SEM) time from diagnosis of hypercalcemia until surgical referral decreased from 2.5 (0.4) years in 1985 to 1.6 (0.2) years in 2005 (P = .08). The primary reason for referral has shifted toward osteoporosis (20% in 2005 vs 7% in 1985; P = .03). The percentage of patients diagnosed with osteoporosis or osteopenia preoperatively increased from 10% in 1985 to 44% in 2005 (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001), and the recognition of these conditions in men increased from 3% to 26% (P = .10). Over the last 3 decades, increased awareness of hyperparathyroidism and its consequences as well as the institution of screening bone densitometry have changed the profile of patients who are referred for surgery. Patients are being referred sooner, with a lesser degree of hypercalcemia and greater recognition of osteoporosis.

Research paper thumbnail of A critical analysis of intraoperative time utilization in laparoscopic adrenalectomy

Surgical endoscopy, 2002

Time and efficiency analysis is a technique common in industry that is being applied to surgical ... more Time and efficiency analysis is a technique common in industry that is being applied to surgical procedures. The aim of this study is to analyze the time spent performing the component parts of laparoscopic adrenalectomy by both the lateral transabdominal and the posterior retroperitoneal approaches. Operational videotapes of 33 patients undergoing laparoscopic adrenalectomy (12 lateral, 21 posterior) were reviewed. The operation was divided into six steps: trocar entry, laparoscopic ultrasonography, exposure of the adrenal gland, dissection of the adrenal, extraction of specimen, and irrigation-aspiration. Time spent for each step and the relation with age, gender, body mass index (BMI), tumor size, side, and histology were assessed using Student's t-test, Pearson correlation, and regression analysis. Although tumor size was larger in the lateral compared to the posterior approach (5.5 vs 2.5 cm, p < 0.001), there was no difference between the groups regarding total operatin...

Research paper thumbnail of Line-associated thrombosis as the major cause of hospital-acquired deep vein thromboses: an analysis from National Surgical Quality Improvement Program data and a call to reassess prophylaxis strategies

American journal of surgery, 2014

Quality improvement has mitigated the occurrence of postoperative deep vein thromboses (DVTs); ho... more Quality improvement has mitigated the occurrence of postoperative deep vein thromboses (DVTs); however, despite adherence to protocols, they continue to occur. This study aimed to characterize their rate and distribution at our institution, and appropriate use of thromboprophylaxis. Local American College of Surgeons National Surgical Quality Improvement Program data were queried for general surgery cases complicated by DVT from 2009 to 2011. Medical records were evaluated to ascertain the following: classify DVTs by site, ascertain if appropriate prophylactic measures were instituted, evaluate treatment instituted, evaluate the occurrence of a PE if the DVT was line-associated, and if so, the indication for the central line. Of 1,857 patients, 39 had postoperative DVTs (2.1%). Fourteen lower-extremity (35.9%) DVTs, 4 central (10%) DVTs, and 21 upper-extremity (53.8%) DVTs (UEDVTs) were captured. All but 2 had appropriate thromboprophylaxis. All but one UEDVT was line-associated. Di...

Research paper thumbnail of The utility of intraoperative ultrasound in modified radical neck dissection: a pilot study

Surgical innovation, 2014

Although the value of surgeon-performed neck ultrasound (SPUS) for thyroid nodules has been valid... more Although the value of surgeon-performed neck ultrasound (SPUS) for thyroid nodules has been validated, the utility of intraoperative ultrasound (US) in modified radical neck dissection (MRND) has not been reported in the literature. The aim of this study was to analyze the utility of intraoperative SPUS in assessing the completeness of MRND for thyroid cancer. Between 2007 and 2011, a total of 25 patients underwent MRND by 1 surgeon for thyroid cancer. All patients underwent intraoperative SPUS, which was repeated at the end of the neck dissection (completion US) to look for missed lymph nodes (LNs). There were 10 male and 15 female patients. Pathology included 23 papillary and 2 medullary carcinomas. The number of LNs removed per case was 23 ± 2, and the number of positive was LNs 5 ± 1. In 4 (16%) cases, intraoperative US detected 7 residual LNs, which would have been missed, if completion US were not done. These missed LNs were located in low-level IV (3 nodes), high-level II (2 ...

Research paper thumbnail of Predicting the Success of Limited Exploration for Primary Hyperparathyroidism Using Ultrasound, Sestamibi, and Intraoperative Parathyroid Hormone

Transactions of the ... Meeting of the American Surgical Association, 2008

The aim of this study was to determine the success of limited neck exploration (LE) for primary h... more The aim of this study was to determine the success of limited neck exploration (LE) for primary hyperparathyroidism (1 degrees HPT). Between 1999 and 2007, 1407 patients with hyperparathyroidism underwent bilateral neck exploration (BE). Of these, 1158 patients with first-time sporadic 1 degrees HPT were analyzed prospectively. Based on surgeon-performed ultrasound (US) and sestamibi scan (MIBI), LE was initially performed. Regardless of results, BE followed to identify the presence of additional parathyroid pathology. Of 1158 patients, 242 (21%) were found to require concomitant thyroid surgery thus excluding LE. Of the remaining 916 patients, a single abnormal gland was identified on MIBI in 682 (74%), US in 731 (80%), and concordance of both in 588 (64%). Unsuspected multiglandular disease (MGD) was identified at BE in 22%, 22%, and 20% of patients, respectively. Adding intraoperative parathyroid hormone sampling (IOPTH) further reduced the rate of unsuspected MGD to 16%, 17%, and 16%. Overall, IOPTH correctly predicted MGD in only 22%. Neither concomitant nonsurgical thyroid disease nor more stringent selection criteria (preop Ca&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;11 mg/dL and PTH&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;120 pg/dL) altered success rates. In patients with MGD, a subsequent gland identified was larger than the index gland in 23%. Ninety-eight percent of BE patients were cured of 1 degrees HPT. This is the largest study to evaluate the prevalence of additional parathyroid pathology in patients who are candidates for LE. Limitations in localizing studies and IOPTH fail to identify MGD in at least 16% of patients, risking future recurrence.

Research paper thumbnail of Ultrasonography for the endocrine surgeon: A valuable clinical tool that enhances diagnostic and therapeutic outcomes

Surgery, 2005

Surgeon-performed ultrasonography (U/S) has revolutionized many subspecialties by broadening the ... more Surgeon-performed ultrasonography (U/S) has revolutionized many subspecialties by broadening the diagnostic and interventional scope of practice. We report our experience on the impact of surgeon-performed U/S in an endocrine surgery practice. Prospectively maintained records of patients from November 1999 to November 2004 were reviewed to establish patterns and outcomes of U/S practice. Surgeon-performed neck U/S was done routinely at the initial clinic visit and incorporated into resident/fellow education. A total of 5703 U/S were performed on endocrine patients with thyroid 42%, parathyroid 57%, and adrenal 1% disorders. Diagnostic fine-needle aspiration biopsy (FNA) was achieved with low sampling errors (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;7%). When U/S identified thyroid nodules coexisting with hyperparathyroidism, preoperative FNA correctly established benign thyroid diagnosis and minimized need for thyroidectomy. U/S successfully imaged abnormal parathyroid glands when (99)Tc-sestamibi scans were negative. U/S data significantly changed treatment plans in nearly two thirds of thyroid cancer patients. Surgical residents readily mastered essential U/S skills. Surgeon-performed U/S is a highly specific tool for identification of endocrine disease in the neck. It is learned readily and performed accurately, and functions as an informative extension of physical examination. Because it substantially benefits patient care and impacts surgical decision making, neck U/S is recommended highly as a valuable adjunct to endocrine surgical practice.

Research paper thumbnail of Robotic Transaxillary Thyroidectomy: Report of 2 Cases and Description of the Technique

Surgical Laparoscopy, Endoscopy & Percutaneous Techniques, 2010

Various techniques for minimally invasive thyroid surgery have been described over the last decad... more Various techniques for minimally invasive thyroid surgery have been described over the last decade. These techniques have significant limitations owing to 2-dimensional view and awkward endoscopic instrumentation. Robotic surgical technology was developed to overcome these limitations. In this case report, we are describing our first 2 thyroid procedures using this technology: a total thyroidectomy in a 66-year old, and a thyroid lobectomy in a 43-year old. We found that robotic resection avoids a neck scar and offers quality 3-dimensional vision with dexterity similar to the human hand.

Research paper thumbnail of Prospective evaluation of sestamibi scan, ultrasonography, and rapid PTH to predict the success of limited exploration for sporadic primary hyperparathyroidism

Surgery, 2004

The aim of this study was to determine the ability of localizing studies and rapid intraoperative... more The aim of this study was to determine the ability of localizing studies and rapid intraoperative parathyroid hormone (PTH) to predict the success of a limited approach in patients who then underwent bilateral exploration. Preoperative sestamibi-iodine subtraction scan and neck ultrasonography (US) were used to direct a focal (1-gland) and unilateral (1-sided) parathyroid exploration by using rapid intraoperative PTH determinations in 350 patients with sporadic primary hyperparathyroidism. Regardless of the findings, the contralateral side was then explored. A single gland was predicted by sestamibi in 290 patients (83%), US in 298 patients (85%), and concordance of both in 205 patients (59%). Unilateral parathyroid exploration, directed by these studies, would correctly identify single-gland disease in only 68%, 74%, and 79%, respectively. The addition of intraoperative PTH would increase the success rate to 73%, 77%, and 82%, respectively. The finding of 2 normal or 2 abnormal glands on 1 side would force bilateral exploration, and additional unsuspected pathology was found in 13%, 13%, and 9%, respectively. This failure rate would increase to 21%, 18%, and 15%, respectively, if the analysis assumed a focal rather than unilateral approach to the initial exploration. Even in patients with concordant sestamibi and US scans, and an appropriate PTH drop, additional abnormal parathyroid glands were found on complete exploration in 15%. A bilateral approach offers the best opportunity for the long-term cure of primary hyperparathyroidism.

Research paper thumbnail of The Impact of Office Neck Ultrasonography on Reducing Unnecessary Thyroid Surgery in Patients Undergoing Parathyroidectomy

Thyroid, 2005

Some have suggested that thyroid disease is even more prevalent among patients with hyperparathyr... more Some have suggested that thyroid disease is even more prevalent among patients with hyperparathyroidism (HPT) than in the general population. We sought to define the incidence and optimal management strategies of thyroid disease in patients undergoing surgery for HPT. Clinical characteristics were reviewed for 1200 consecutive HPT patients treated at two endocrine surgery referral centers from 1992-2003. Both centers practice bilateral neck exploration, and one routinely obtains preoperative neck ultrasound (US) performed by surgeons. Forty percent (477/1195) of HPT patients had coexisting thyroid disease, whether identified at parathyroidectomy (39%; 327/845) or by US (43%; 150/350). Colloid nodules/goiters accounted for nearly half of thyroid pathology, followed by follicular adenomas, papillary cancer, thyroiditis, and intrathyroidal parathyroids. Thyroid malignancy was found in 4.6% of HPT patients versus less than 1% in autopsy reports. Thyroid pathology was similar among single adenomas, multigland, and renal HPT. Unexpected thyroid disease first encountered at parathyroidectomy required partial or total thyroidectomy in 30% (257/845). US-detected thyroid nodules prompted fine-needle biopsy in 20%, which was cost effective in limiting concomitant thyroid surgery to fewer patients (6%; 21/350). Overall low incidence (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.5%) of persistent/recurrent HPT, nerve injury, and neck hematoma was unaffected by thyroid abnormalities. The high prevalence of thyroid disease, especially malignancies, among HPT patients mandates vigilant diagnosis and preparation for possible simultaneous parathyroid-thyroid surgery. Without appropriate preoperative screening, focal explorations for HPT may be prone to delayed diagnosis of thyroid tumors. Ultrasound performed by surgeons or endocrinologists preoperatively is an excellent diagnostic tool and minimizes unnecessary thyroidectomy in patients with subclinical thyroid disease.

Research paper thumbnail of A new risk stratification algorithm for the management of patients with adrenal incidentalomas

Surgery, 2014

Although adrenal incidentalomas (AI) are detected in ≤5% of patients undergoing chest and abdomin... more Although adrenal incidentalomas (AI) are detected in ≤5% of patients undergoing chest and abdominal computed tomography (CT), their management is challenging. The current guidelines include recommendations from the National Institutes of Health, the American Association of Endocrine Surgeons (AAES), and the American Association for Cancer Education (AACE). The aim of this study was to develop a new risk stratification model and compare its performance against the existing guidelines for managing AI. A risk stratification model was designed by assigning points for adrenal size (1, 2, or 3 points for tumors &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;4, 4-6, or &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;6 cm, respectively) and Hounsfield unit (HU) density on noncontrast CT (1, 2, or 3 points for HU &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;10, 10-20, or &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;20, respectively). This model was applied retrospectively to 157 patients with AI managed in an endocrine surgery clinic to assign a score to each tumor. The utility of this model versus the AAES/AACE guidelines was assessed. Of the 157 patients, 54 (34%), had tumors &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;4 cm with HU &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;10 (a score of 2). One third of these were hormonally active on biochemical workup and underwent adrenalectomy. The remaining two thirds were nonsecretory lesions and have been followed conservatively with annual testing. In 103 patients (66%), the adrenal mass was &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;4 cm and/or had indeterminate features on noncontrast CT (HU &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;10, irregular borders, heterogeneity), and adrenalectomy was performed after hormonal evaluation was completed (10 were hormonally active on biochemical testing). Seven of these patients (7%) had adrenocortical cancer on final pathology with tumor size &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;4 cm in 0, 4-6 cm in 1, and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;6 cm in 5 patients. Of the hormonally inactive patients, 32% had a score of 3, 38% 4, and 30% 5 or 6. The incidence of adrenocortical cancer in these subgroups was 0, 0, and 25%, respectively. This study shows that an algorithm that utilizes the hormonal activity at the first decision step followed by a consolidated risk stratification, based on tumor size and HU density, has a potential to spare a substantial number of patients from unnecessary &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;diagnostic&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; surgery for AI.

Research paper thumbnail of An analysis of whether surgeon-performed neck ultrasound can be used as the main localizing study in primary hyperparathyroidism

Surgery, 2014

Tc-99 sestamibi (MIBI) scan is the imaging study most frequently used in primary hyperparathyroid... more Tc-99 sestamibi (MIBI) scan is the imaging study most frequently used in primary hyperparathyroidism (PHP). Transcutaneous cervical ultrasonography (US) is the other modality used for preoperative localization. The aim of this study was to determine whether surgeon-performed neck US can be used as the primary localizing study in PHP. This was a prospective study of 1,000 consecutive patients with first-time, sporadic PHP who underwent parathyroidectomy at a tertiary academic center. All patients had surgeon-performed neck US and MIBI before bilateral neck exploration. The findings at exploration were 72% single adenoma, 15% double adenoma, and 13% hyperplasia. When US suggested single-gland disease (n = 842), MIBI was concordant in 82.5%, discordant and false in 8%, negative in 7%, and discordant but correct in 2.5%. When US suggested multigland disease (n = 68), MIBI was concordant in 47%, discordant and false in 41%, and negative in 12%. When US was negative (n = 90), MIBI was positive and correct in 43%, negative in 31%, and positive but false in 26%. Surgeon-performed neck US identified unrecognized thyroid nodules in 326 patients (33%), which led to fine-needle aspiration biopsy in 161 (49%) patients and thyroid surgery in 103 (32%) patients, with a final diagnosis of thyroid cancer in 24 (7%) patients. Our results show that MIBI provides additional useful information in only a minority of patients with a positive US in PHP. Nevertheless, MIBI benefits about half of patients with a negative US. Because one-third of this patient population has unrecognized thyroid nodules as well, we propose that the most cost-effective algorithm would be to do US first and reserve MIBI for US-negative cases.

Research paper thumbnail of Laparoscopic ultrasonography and biopsy of hepatic tumors in 310 patients

The American Journal of Surgery, 2004

Background: Laparoscopic ultrasonography is increasingly being recognized as an important tool in... more Background: Laparoscopic ultrasonography is increasingly being recognized as an important tool in the evaluation of patients with possible hepatic tumors. The aim of this paper is to describe the technical aspects of imaging and biopsy based on our experience in 310 patients with 1,080 primary and metastatic liver tumors within a 6.5-year period. Methods: A 10-mm rigid or flexible, 7.5 MHz linear, side-viewing laparoscopic ultrasonography probe was used for imaging, and an 18G spring-loaded core biopsy gun was used for tissue diagnosis. Results: There were no complications. The entire liver was imaged using a right subcostal port. Using a free-hand technique, the needle was best targeted into the lesion when inserted parallel to the plane of the transducer. The rigid transducer was found to be more convenient to guide needle placement. Conclusions: The use of this minimally invasive technique avoids laparotomy in many patients undergoing staging of malignancy and also offers increased sensitivity for tumor detection compared with conventional imaging modalities.

Research paper thumbnail of Predictors of recurrence in pheochromocytoma

Surgery, 2014

Background. The recurrence rate of pheochromocytoma after adrenalectomy is 6.5-16.5%. This study ... more Background. The recurrence rate of pheochromocytoma after adrenalectomy is 6.5-16.5%. This study aims to identify predictors of recurrence and optimal biochemical testing and imaging for detecting the recurrence of pheochromocytoma. Methods. In this retrospective study we reviewed all patients who underwent adrenalectomy for pheochromocytoma during a 14-year period at a single institution. Results. One hundred thirty-five patients had adrenalectomy for pheochromocytoma. Eight patients (6%) developed recurrent disease. The median time from initial operation to diagnosis of recurrence was 35 months. On multivariate analysis, tumor size >5 cm was an independent predictor of recurrence. One patient with recurrence died, 4 had stable disease, 2 had progression of disease, and 1 was cured.