Not deep enough: Modeling the effect of shallow placement of the DaVinci Xi "bariatric" long trocar on the muscular abdominal wall.

INTRODUCTION: The DaVinci Xi Robotic Surgical System (Xi) long cannula (Intuitive Surgical Company, Sunnyvale, CA) provides five additional centimeters of distal length compared to the standard Xi trocar. The extra length allows the cannula to traverse prohibitively thick body wall tissue. Our aims are to quantitatively model the consequences of not preserving the rotational centerpoint of motion (RCM) at the muscular abdominal wall. This is an essential tenet in robotic surgery; it is violated with shallow placement of the long trocar. This leads to unchecked, unnoticed blunt widening of port sites by the robotic arm, increasing hernia risk. METHODS: We begin with an exploration of the schematic of the Xi robotic arm as patented by Intuitive (U.S. Patent #5931832). We trigonometrically model the lateral displacement of the abdominal wall at the trocar site with respect to vertical trocar shallowness, instrument tip depth, and instrument tip lateral motion from neutral midline. RESULTS: The rigid parallelogram movement structure of the Xi preserves the RCM at the thick black marker printed on every Xi cannula. By limitation of design, both long and standard trocars must have this marker at the exact same distance from their proximal end. The value ranges of our model parameters (presuming a reasonable maximum orientation angle of 45° from midline) are: trocar shallowness [1 cm, 7 cm]; instrument tip depth [0 cm, 20 cm]; instrument tip lateral movement [0.0 cm, 14.1 cm]. Abdominal wall displacement increased proportionally as each instrument tip parameter reached its maximum deviation from the orthogonal midline as described in the plot figure. Maximal wall displacement at maximal shallowness was approximately 7.0 cm. CONCLUSION: Robotic surgery revolutionizes modern operation, particularly within bariatrics. However, the current Xi arm design disallows a true long trocar to be used safely without compromising the RCM, thereby risking hernia development.

Management of Hypercalcemic Crisis due to Primary Hyperparathyroidism During Pregnancy.

Primary hyperparathyroidism is the third most common endocrine disorder following diabetes and thyroid disease. Women are affected by primary hyperparathyroidism twice as often as men. The first reported case of hyperparathyroidism during pregnancy was in 1931. More recent data suggests that hyperparathyroidism during pregnancy is diagnosed in .5-1.4% of women. Symptoms of primary hyperparathyroidism, such as fatigue, lethargy, and proximal muscle weakness are nonspecific and could be mistaken as complaints naturally present during pregnancy; however, maternal complications in patients with hyperparathyroidism can be as high as 67%. We present a case of a pregnant patient who presented in hypercalcemic crisis with a concomitant diagnosis of primary hyperparathyroidism.

Comparing Payments to Surgeons From Drug and Medical Device Corporations Reveals Inequalities Between Genders and Specialties.

INTRODUCTION: Maintaining trust in the patient-doctor relationship requires transparency in the details of the financial relationships between physicians and drug and medical device corporations. These details are publicly available through the Open Payments database, and patients are encouraged to ask surgeons to interpret their implications. The purpose of this study was to better equip surgeons in responding to these inquiries and to compare the distribution of these payments by gender and specialty. METHODS: The 2021 Open Payments dataset was searched for all payments to surgeons from the 14 different specialties recognized by the American College of Surgeons. The total payments per surgeon were compared by calculating the mean and median payments. The Gini index, a measure of income inequality, was also calculated for each specialty. RESULTS: There were 96 724 surgeons who received over $755 million in payments from drug and medical device companies. There were 72 245 (74.7%) men and 24 479 (25.3%) women. The total amount of payments to men was $712 million (94.2%) and for women it was $44 million (5.8%). The overall Gini index was .9508. The specialty with the highest Gini index was pediatric surgery (.9844) and the lowest was cardiothoracic surgery (.8656). DISCUSSION: Male surgeons received disproportionately higher payments from drug and device corporations than female surgeons. Surgeons should be aware of their own standing within the Open Payments database in order to respond appropriately to patient inquiries.

From Palm Leaves to Thermoplastic Polyurethanes-The History of Vascular Catheter Development and Use.

Vascular catheterization procedures are performed on millions of patients in the United States annually. Diagnostic and therapeutic, these procedures allow for the detection and treatment of diseased vessels. The use of catheters, however, is no new phenomenon. Ancient Egyptians, Greeks, and Romans constructed tubes from hollow reeds and palm leaves to be tunneled through the vasculature of cadavers to study cardiovascular system function, while eighteenth century English physiologist Stephen Hales used a brass pipe cannula to perform the first central vein catheterization on a horse. In 1963, American surgeon Thomas Fogarty developed a balloon embolectomy catheter, while in 1974, German cardiologist Andreas Grüntzig developed a more refined angioplasty catheter using polyvinyl chloride with improved rigidity. Vascular catheter material has since continued to evolve and is tailored to the specific needs of the procedure but would not have been possible without its rich and diverse history of development.

Financial Toxicity in Emergency General Surgery: Novel Propensity-Matched Outcome Comparison.

BACKGROUND: Financial toxicity describes the harmful effect of individual treatment costs and fiscal burdens that have a compounding negative impact on outcomes in surgery. While this phenomenon has been widely studied in surgical oncology, the purpose of this study was to perform a novel exploration of the impact of financial toxicity in emergency general surgery (EGS) patients throughout the US. STUDY DESIGN: The Nationwide Readmissions Database for January and February 2018 was queried for all EGS patients aged 18 to 65 years. One-to-one propensity matching was performed with and without risk for financial toxicity. The primary outcome was mortality, and the secondary outcomes were venous thromboembolism (VTE), prolonged length of stay (LOS), and readmission within 30 days. RESULTS: There were 24,154 EGS patients propensity matched. The mortality rate was 0.2% (n = 39), and the rate of VTE was 0.5% (n = 113). With financial toxicity, there was no statistically significant difference for mortality (p = 0.08) or VTE (p = 0.30). The rate of prolonged LOS was 6.2% (n = 824), and the risk was increased with financial toxicity (risk ratio 1.24 [1.12 to 1.37]; p < 0.001). The readmission rate was 7.0% (n = 926), and the risk with financial toxicity was increased (risk ratio 1.21 [1.10 to 1.33]; p < 0.001). The mean count of comorbidities per patient per admission during readmission within 1 year with financial toxicity was 2.1 ± 1.9 versus 1.8 ± 1.7 without (p < 0.001). CONCLUSIONS: Despite little difference in the rate of mortality or VTE, EGS patients at risk for financial toxicity have an increased risk of readmission and longer LOS. Fewer comorbidities were identified at index admission than during readmission in patients at risk for financial toxicity. Future studies aimed at reducing this compounding effect of financial toxicity and identifying missed comorbidities have the potential to improve EGS outcomes.

Nationwide Analysis of Hospital Admissions Prior to Hartmann's Procedure for Acute Diverticulitis.

INTRODUCTION: Diverticular disease is one of the most common gastrointestinal diseases that require hospital admission. This study aims to identify trends in prior hospital admissions for patients that ultimately require a Hartmann's procedure for complicated diverticulitis. METHODS: The Nationwide Readmissions Database for 2010-2014 was queried for all patients aged 18 years or older admitted with an ICD-9 code for colonic diverticulitis and end colostomy creation. Patients with prior hospital admissions were identified. The primary outcome was mortality after Hartmann's procedure. Secondary outcomes were prior hospital admission and previous percutaneous drain placement. Multivariable logistic regression was performed to control for confounding factors for each outcome and results were weighted for national estimates. RESULTS: There were 90,162 patients admitted with complicated diverticulitis requiring end colostomy creation. Prior hospital admissions were found in 28.1% (n = 25,307) and 14.4% (n = 12,947) had a previous percutaneous drain placed during a prior admission. The overall mortality rate was 5.9% (n = 5314) after Hartman's procedure. The mortality rate for patients with prior hospital admissions was 8.7% (P < .001), and the mortality rate for patients with previous percutaneous drain placement was 4.3% (P < .001). After controlling for confounding factors including comorbidities, patients with prior admission had an increased risk of mortality (OR 1.48 [1.40-1.58], P < .001) and patients with previous percutaneous drain placement had a decreased risk of mortality (OR .66 [.60-.72], P < .001). CONCLUSIONS: Hospitalizations for complications of diverticulitis are a costly burden to our healthcare system. By identifying those patients at high risk for readmission and emergency surgery, perioperative outcomes may be improved.

Under the Microscope: The Evolution of Surgical Loupes.

Fine motor movements of the surgeon's hands are limited by the resolution of the eye. Surgical loupes have allowed the profession of surgery to surpass this threshold. This is a review of the historical milestones that lead up to the development of the modern-day loupes. We explore the Greco-Roman history of the magnifying lens, its subsequent application to corrective eyewear centuries later, and the multiple ground-breaking advancements of the compound lens microscope. Moreover, we review the development of pre-modern loupes as each iteration improved through time. The aim of this historical review is to kindle an appreciation for the millennia of development that led to such instrumental modern-day technology.

The Evolution of Bariatric Surgery-From Sewing Lips to Constructing the Sleeve.

Bariatric surgery remains the most durable weight loss option to address morbid obesity, providing lasting reduction of debilitating chronic comorbidities. This is a review of the historical milestones that led up to the development of this surgical practice. We explore perceptions and interventions for obesity as early as the 10th century, as well as pre-modern surgical perceptions and advancements in foregut and obesity surgery. Additionally, we recount select social and surgical landmarks in the modern bariatric era. The aim of this review is to reflect on and appreciate the centuries of progress that have led to such an instrumental branch of risk reductive surgery.

Not all laparoscopic adrenalectomies are equal: analysis of postoperative outcomes based on tumor functionality.

BACKGROUND: Laparoscopic adrenalectomy is known to have a low complication rate; however, the influence of functional tumor subtype on postoperative outcomes is not well defined. METHODS: Patients undergoing laparoscopic adrenalectomy for benign adrenal tumors between 2009 and 2017 were selected from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Patient demographics, postoperative outcomes, and length of stay were compared between tumor subtypes. RESULTS: A total of 3946 patients underwent a laparoscopic adrenalectomy during the study period; 3214 (81.5%) were performed for non-functional adenomas, and 732 (18.6%) for functional tumors-467 (64%) aldosteronomas, 184 (25%) cortisol-producing adenomas, and 81 (11%) pheochromocytomas. The risk of any complication was highest for patients with Cushing's (6.5%) and lowest with Conn's syndrome (1.1%) compared to other lesions (3.7% pheochromocytoma, 5.3% adenoma, p < 0.001). Among the patients with functional tumors, those with cortisol-producing adenomas had the highest rates of both deep surgical site infection (1.6%, p = 0.026) and urinary tract infection (2.2%, p = 0.029), whereas myocardial infarction was most prevalent in patients with pheochromocytoma (2.5%, p = 0.012). When adjusted for demographic differences, BMI, and comorbidity scores, no tumor type was associated with increased complication rate; instead aldosteronoma (vs. benign adenoma) was independently predictive of fewer adverse events [0.3 (95% CI 0.1-0.7), p = 0.004] and a shorter length of hospital stay [0.6 (95% CI 0.4-0.8), p = 0.001]. The overall mortality rate was low at 0.4%, although significantly higher in Cushing's patients (2.2%, p = 0.015). CONCLUSIONS: Laparoscopic adrenalectomy is a safe operation with low mortality and complication rates. However, postoperative risks differ between tumor subtype, so patients should be counseled accordingly.

Does Aggressive Variant Histology Without Invasive Features Predict Overall Survival in Papillary Thyroid Cancer?: A National Cancer Database Analysis.

OBJECTIVE: We aimed to clarify whether aggressive histology of papillary thyroid cancer (PTC) impacts overall survival (OS). SUMMARY BACKGROUND DATA: Aggressive variants of PTC (AVPTC) are associated with invasive features. However, their behavior in the absence of these features is not well characterized. METHODS: Patients treated from 2004 to 2015 for classic PTC (cPTC) or AVPTCs were identified from the National Cancer Database. Patients were further stratified based on presence of at least 1 invasive feature-extrathyroidal extension, multifocality, lymphovascular invasion, nodal or distant metastasis. Demographics, treatments, and OS were compared. RESULTS: A total of 170,778 patients were included-162,827 cPTC and 7951 AVPTC. Invasive features were more prevalent in AVPTC lesions compared to cPTC (70.7% vs 59.7%, P < 0.001). AVPTC included tall cell/columnar cell (89.5%) and diffuse sclerosing (10.5%) variants. Patients with invasive features had worse OS irrespective of histology. Furthermore, when controlling for demographics, tumor size, and treatment variables in patients with noninvasive lesions, AVPTC histology alone was not associated with worse OS compared to cPTC (P = 0.209). In contrast, among patients who had at least 1 invasive feature, AVPTC histology was independently predictive of worse OS (P < 0.05) {TCV/Columnar hazard ratio [HR] 1.2; [95% confidence interval (CI) 1.1-1.3] and diffuse sclerosing HR 1.3; 95% CI 1.0-1.7]}. All invasive features, except multifocality, were independently associated with worse OS, with metastasis being the most predictive [HR 2.9 (95% CI 2.6-3.2) P < 0.001]. CONCLUSIONS: In the absence of invasive features, AVPTC histology has similar OS compared to cPTC. In contrast, diffuse sclerosing and tall cell/columnar variants are associated with worse OS when invasive features are present.

Hospital Readmissions for Hyperparathyroidism After Bariatric Surgery in the United States: A National Database Review.

INTRODUCTION: The incidence and significance of hyperparathyroidism in patients after bariatric surgery have been established to some degree; however, the impact it has on the national healthcare system has not. We sought to assess the risk of readmission and related comorbidities in this patient population. METHODS: The Healthcare Cost and Utilization Project Nationwide Readmission Database was queried for all patients who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). Multivariate logistic regression analysis was conducted to identify factors associated with readmission for hyperparathyroidism. RESULTS: A total of 915,792 patients between 2010 and 2015 were queried; 43.2% had undergone SG and 56.8% had RYGB. A total of 589 patients were readmitted for hyperparathyroidism; 80.8% were female and 68% had a Charlson comorbidity index ≥ 2. Factors associated with readmission were as follows: age 45-64 years (odds ratio [OR] 1.42, p=0.001), Medicare (OR 3.01, p<0.001) or Medicaid (OR 2.61, p<0.001) insurance status, lower median household income, renal failure (OR 17.14, p<0.001), hypertension (OR 2.89, p<0.001), and deficiency anemia (OR 2.62, p<0.01). CONCLUSIONS: Parathyroid axis monitoring may provide benefits to predictably high-risk patients. Appropriate surveillance may decrease the impact of bariatric hyperparathyroidism readmission on the U.S. healthcare system.

Thoracic Duct Embolization in Post-neck Dissection Chylous Leakage: A Case Series of Six Patients and Review of the Literature.

Chylous leak is a serious complication of neck dissection. Patients are often managed conservatively, and failure of conservative management necessitates surgical management, which adds to their morbidity. We present a case series demonstrating the value of thoracic duct embolization (TDE) in management of patients with chylous leaks following neck dissection who have failed conservative management and to review the literature on this specific application of TDE. Between 2011 and 2019, six patients underwent a total of seven TDE procedures. Lymphatic leak was identified, and clinical success was achieved in all patients, with one patient requiring repeat TDE. No minor or major complications were reported. In conclusion, TDE is a safe and effective tool in management of chylous leaks following neck dissection.

Dual inhibition of BRAF and MEK increases expression of sodium iodide symporter in patient-derived papillary thyroid cancer cells in vitro.

BACKGROUND: The majority of papillary thyroid cancers are driven by acquired mutations typically in the BRAF or RAS genes that aberrantly activate the mitogen-activated protein kinase pathway. This process leads to malignant transformation, dedifferentiation, and a decrease in the expression of the sodium-iodide symporter (NIS; SLC5A5), which results in resistance to radioactive iodine therapy. We sought to determine whether inhibition of aberrant mitogen-activated protein kinase-signaling can restore NIS expression. METHODS: We prospectively developed cultures of papillary thyroid cancers derived from operative specimens and applied drug treatments for 24 hours. Samples were genotyped to identify BRAF and RAS mutations. We performed quantitative PCR to measure NIS expression after treatment. RESULTS: We evaluated 24 patient papillary thyroid cancer specimens; BRAFV600E mutations were identified in 18 out of 24 (75.0%); 1 patient tumor had an HRAS mutation, and the remaining 5 were BRAF and RAS wildtype. Dual treatment with dabrafenib and trametinib increased NIS expression (mean fold change 4.01 ± 2.04, P < .001), and single treatment with dabrafenib had no effect (mean fold change 0.98 ± 0.42, P = .84). Tumor samples that had above-median NIS expression increases came from younger patients (39 vs 63 years, P < .05). CONCLUSION: Dual treatment with BRAF and MEK inhibitors upregulated NIS expression, suggesting that this treatment regimen may increase tumor iodine uptake. The effect was greatest in tumor cells from younger patients.

Insights into the biology and treatment strategies of pancreatic neuroendocrine tumors.

Pancreatic neuroendocrine tumors (PNETs) are the second most common primary pancreatic neoplasms after pancreatic ductal adenocarcinoma. PNETs present with widely various clinical manifestation and unfavorable survival rate. The recent advances in next generation sequencing have significantly increased our understanding of the molecular landscape of PNETs and help guide the development of targeted therapies. This review intends to outline a holistic picture of the tumors by discussing current understanding of clinical presentations, up-to-date treatment strategies, novel mouse models, and molecular biology of PNETs. Furthermore, we will provide insight into the future development of more effective targeted therapies that are necessary to manage PNETs.

The 2015 American Thyroid Association guidelines are associated with an increasing rate of hemithyroidectomy for thyroid cancer.

BACKGROUND: In an attempt to prevent overly aggressive treatment of low-risk thyroid cancers, the American Thyroid Association changed guideline recommendations in late 2015 to state that either hemithyroidectomy or total thyroidectomy are acceptable operations for these patients. We hypothesized that surgeons would increasingly perform hemithyroidectomy after the release of these guidelines. METHODS: The database of the National Surgery Quality Improvement Program was queried to identify all patients with thyroid cancer who were undergoing thyroidectomy between 2009 and 2017. Patients treated before the release of the 2015 American Thyroid Association guidelines were compared with those treated afterward. Temporal trends in operative rates were assessed quarterly using interrupted time series analyses. RESULTS: A total of 35,291 patients were included in the study. Of those, 26,882 (76.2%) were female and 25,193 (71.3%) were white. After the release of the American Thyroid Association guidelines, there was an increase in hemithyroidectomy rate for patients with cancer from 17.3% to 22.0% (P < .001). Interrupted time series analysis controlling for patient factors demonstrated that quarterly growth in the hemithyroidectomy rate accelerated almost 10-fold (P < .001) after publication of the revised guidelines. Of note, there was no corresponding increase in the completion thyroidectomy rate (8.3% versus 7.9%, respectively, P = .213). Patients treated with hemithyroidectomy were more likely to be managed as outpatients (70.8% versus 57.1%, P < .001), had fewer surgical site infections (0.3% versus 0.5%, P = .050), and had fewer unplanned reintubations (0.2% versus 0.4%, P = .005). CONCLUSION: In hospitals participating in the National Surgery Quality Improvement Program, the hemithyroidectomy rate increased significantly after the release of the 2015 American Thyroid Association guidelines. Surgeons at hospitals that participate in the National Surgery Quality Improvement Program may be changing practice patterns in response to these guidelines.

Disparities in pediatric gonadal torsion: Does gender, race and insurance status affect outcomes?

PURPOSE: Ovarian and testicular torsions are emergencies requiring prompt surgical treatment to preserve gonadal function. However, diagnosis in females is often delayed owing to nonspecific symptoms. We sought to assess disparities in management and outcomes between males and females with torsion. METHODS: The National Inpatient Sample was queried for pediatric patients with "emergent", "urgent", or "trauma center" admission and ICD-9 codes for ovarian torsion and testicular torsion. Demographic data, operative procedure, gonadal loss, length of stay (LOS), total charges (TC), and mortality were recorded. RESULTS: There were 2254 unweighted encounters. The average age was 11.56±5.30years for males and 12.55±3.72years for females (p<0.001). Among males, 90% underwent surgery (p<0.001), of which 40% required orchiectomy. Conversely, 73% of females had surgery (p<0.001), of which 78% had oophorectomy. Subsequent analysis with only patients who underwent surgery showed that insurance status (p=0.012), race (p<0.001), and U.S. region (p<0.001) were significantly different between males and females. Gender specific analyses showed that hospital control, hospital location/teaching status, and treatment year were also significant. As such, these six factors in addition to age and gender were used for propensity score matching (PSM). PSM produced two gender cohorts of 755 encounters each. Females had longer LOS (2.44±1.84days vs. 1.28±2.27days for males, p<0.001) and had higher TC ($20,058.44±13,420.82) compared to males ($12,386.58±12,793.34), p<0.001. Logistic regression revealed that males (OR 0.163 [0.130-0.206]) and older patients (age OR 0.924 [0.903-0.946]) were less likely to undergo gonadal loss. Compared to those with private insurance, those with Medicare/Medicaid were more likely to have gonadal loss (1.401 [1.101-1.783]). CONCLUSION: Disparities exist in the management of torsion based on gender. Overall, females had higher charges, had longer hospitalization, and were more likely to have gonadal loss despite current data supporting gonadal preservation for nearly all cases of ovarian torsion. CLINICAL STUDY: Level III Evidence.

Thirty-day readmissions following parathyroidectomy: Evidence from the National Readmissions Database, 2013-2014.

PURPOSE: Parathyroidectomy is one of the most common procedures performed in the United States, and are increasingly being performed safely in the outpatient setting. However, complications from surgery can be life-threatening, and thus an understanding of who may be at risk is essential. We analyzed and compared the risk factors for patients readmitted within 30 days following inpatient parathyroidectomy for primary or secondary hyperparathyroidism. MATERIALS AND METHODS: We reviewed the National Readmissions Database from 2013 to 2014 for patients who received inpatient parathyroidectomy for primary or secondary hyperparathyroidism. The primary outcome was non-elective readmission within 30 days. Multivariate logistic regression was used to analyze risk factor odds ratios for readmission. RESULTS: 7171 patients underwent inpatient parathyroidectomies in 2013 and 2014. 59.89% of parathyroidectomies were performed for primary hyperparathyroidism, with a 5.6% readmission rate. Most common causes of readmission were septicemia (13.69%), hypocalcemia (12.86%), heart failure (10.79%) and renal failure (9.54%). Having Medicare (OR: 1.71, CI:1.14-2.59, p = .01), Medicaid (OR: 3.24, CI: 2.03-5.17, p < .001), and self-paying (OR: 2.43, CI: 1.11-5.32, p = .02), were associated with increased odds of readmission for those with primary hyperparathyroidism. 21.99% of parathyroidectomies were performed for secondary hyperparathyroidism, with a 19.4% readmission rate. Most common causes of readmission were hypocalcemia (22.88%), hungry bone syndrome (14.38%), electrolyte disorders (13.73%), and renal failure (11.11%). CONCLUSION: Patients with secondary hyperparathyroidism are older, poorer and have more comorbidities than patients with primary hyperparathyroidism, and are more likely to be readmitted within 30 days of parathyroidectomy.

The Sestamibi Paradox: Improving Intraoperative Localization of Parathyroid Adenomas.

Accurate localization of parathyroid adenomas allows for minimally invasive parathyroidectomy. This results in a shorter length of stay and increased patient satisfaction. Preoperative Technetium (99mTc) sestamibi scans accurately localize parathyroid adenomas in 70 to 85 per cent of cases. If a patient has a negative scan, it is logical to believe that with a preoperative sestamibi injection, the gamma probe may fail to help find an adenoma. We hypothesized that the gamma probe would not be useful intraoperatively for patients with primary hyperparathyroidism (PHPTH) and a negative sestamibi scan. We retrospectively reviewed the cases of parathyroidectomy at our institution from 2010 to 2016. We selected patients with PHPTH and negative sestamibi scan. In all cases, an attempt was made to find adenomas intraoperatively with the gamma probe. A frozen section was obtained as well as intraoperative parathyroid hormone levels to confirm removal of hyperfunctioning parathyroid tissue. There were 132 parathyroidectomies of which 22 had PHPTH and a negative sestamibi scan. One case was excluded because of insufficient documentation of the intraoperative use of the gamma probe. In 19 of the 21 patients analyzed, the gamma probe successfully identified the adenoma in the operating room (sensitivity, 90.5%). In two patients, the gamma probe did not aid in localization. There were no false positives. In all cases, the parathyroid resected was confirmed by frozen section. The intraoperative parathyroid hormone levels dropped >50 per cent in all but three cases, two of which corresponded to those cases where the gamma probe did not help. Even in patients with negative sestamibi scans, intraoperative use of the gamma probe after preoperative sestamibi injection is effective in localizing parathyroid adenomas.