The integration of artificial intelligence in robotic surgery: A narrative review.

BACKGROUND: The rise of high-definition imaging and robotic surgery has independently been associated with improved postoperative outcomes. However, steep learning curves and finite human cognitive ability limit the facility in imaging interpretation and interaction with the robotic surgery console interfaces. This review presents innovative ways in which artificial intelligence integrates preoperative imaging and surgery to help overcome these limitations and to further advance robotic operations. METHODS: PubMed was queried for "artificial intelligence," "machine learning," and "robotic surgery." From the 182 publications in English, a further in-depth review of the cited literature was performed. RESULTS: Artificial intelligence boasts efficiency and proclivity for large amounts of unwieldy and unstructured data. Its wide adoption has significant practice-changing implications throughout the perioperative period. Assessment of preoperative imaging can augment preoperative surgeon knowledge by accessing pathology data that have been traditionally only available postoperatively through analysis of preoperative imaging. Intraoperatively, the interaction of artificial intelligence with augmented reality through the dynamic overlay of preoperative anatomical knowledge atop the robotic operative field can outline safe dissection planes, helping surgeons make critical real-time intraoperative decisions. Finally, semi-independent artificial intelligence-assisted robotic operations may one day be performed by artificial intelligence with limited human intervention. CONCLUSION: As artificial intelligence has allowed machines to think and problem-solve like humans, it promises further advancement of existing technologies and a revolution of individualized patient care. Further research and ethical precautions are necessary before the full implementation of artificial intelligence in robotic surgery.

Outpatient surgery benchmarks and practice variation patterns: Case controlled study.

BACKGROUND: Despite numerous potential benefits of outpatient surgery, there is currently a lack of national benchmarking data available for hospitals and surgeons to compare their own outcomes as they transition toward outpatient surgery. MATERIALS AND METHODS: Patients who underwent 14 common general surgery operations from 2016-2020 were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Operations were selected based on frequency and the ability to be performed both in- and outpatient. Postoperative complications and readmissions were compared between patients who underwent inpatient vs outpatient surgery. After adjusting for patient comorbidities, multivariable models assessed the effect of patient characteristics on the odds of experiencing postoperative complications. A separate multiinstitutional study of 21 affiliated hospitals assessed practice variation. RESULTS: In 13 of the 14 studied procedures, complications were lower for patients who were selected for outpatient surgery (all P<0.01); minimally invasive (MIS) adrenalectomy showed no difference (P=0.61). Multivariable analysis confirmed these findings; the odds of experiencing any adverse events were lower following outpatient surgery in all operations but MIS adrenalectomy (OR 0.97; 95% CI 0.47-2.02). Analysis of institutional practices demonstrated variation in the rate of outpatient surgery in certain breast, endocrine, and hernia repair operations. CONCLUSIONS: Institutional practice patterns may explain the national variation in the rate of outpatient surgery. While the present data does not support the adoption of outpatient surgery to less optimal candidates, addressing unexplained practice variations could result in improved utilization of outpatient surgery.

Outcomes of Neoadjuvant Chemotherapy for Invasive Intraductal Papillary Mucinous Neoplasm Compared with de Novo Pancreatic Adenocarcinoma.

BACKGROUND: The management of invasive intraductal papillary mucinous cystic neoplasm (I-IPMN) does not differ from de novo pancreatic ductal adenocarcinoma (PDAC); however, I-IPMNs are debated to have better prognosis. Despite being managed similarly to PDAC, no data are available on the response of I-IPMN to neoadjuvant chemotherapy. METHODS: All patients undergoing pancreatic resection for a pancreatic adenocarcinoma from 2011 to 2022 were included. The PDAC and I-IPMN cohorts were compared to evaluate response to neoadjuvant therapy (NAT) and overall survival (OS). RESULTS: This study included 1052 PDAC patients and 105 I-IPMN patients. NAT was performed in 25% of I-IPMN patients and 65% of PDAC patients. I-IPMN showed a similar pattern of pathological response to NAT compared with PDAC (p = 0.231). Furthermore, positron emission tomography (PET) response (71% vs. 61%; p = 0.447), CA19.9 normalization (85% vs. 76%, p = 0.290), and radiological response (32% vs. 37%, p = 0.628) were comparable between I-IPMN and PDAC. A significantly higher OS and disease-free survival (DFS) of I-IPMN was denoted by Kaplan-Meier analysis, with a p-value of < 0.001 in both plots. In a multivariate analysis, I-IPMN histology was independently associated with lower risk of recurrence and death. CONCLUSIONS: I-IPMN patients have a longer OS and DFS after surgical treatment when compared with PDAC patients. The more favorable oncologic outcome of I-IPMNs does not seem to be related to early detection, as I-IPMN histological subclass is independently associated with a lower risk of disease recurrence. Moreover, neoadjuvant effect on I-IPMN was non-inferior to PDAC in terms of pathological, CA19.9, PET, and radiological response and thus can be considered in selected patients.

Academic Surgery in the Era of Large Language Models: A Review.

Importance: This review aims to assess the benefits and risks of implementing large language model (LLM) solutions in an academic surgical setting. Observations: The integration of LLMs and artificial intelligence (AI) into surgical practice has generated international attention with the emergence of OpenAI's ChatGPT and Google's Bard. From an administrative standpoint, LLMs have the potential to revolutionize academic practices by reducing administrative burdens and improving efficiency. LLMs have the potential to facilitate surgical research by increasing writing efficiency, building predictive models, and aiding in large dataset analysis. From a clinical standpoint, LLMs can enhance efficiency by triaging patient concerns and generating automated responses. However, challenges exist, such as the need for improved LLM generalization performance, validating content, and addressing ethical concerns. In addition, patient privacy, potential bias in training, and legal responsibility are important considerations that require attention. Research and precautionary measures are necessary to ensure safe and unbiased use of LLMs in surgery. Conclusions and Relevance: Although limitations exist, LLMs hold promise for enhancing surgical efficiency while still prioritizing patient care. The authors recommend that the academic surgical community further investigate the potential applications of LLMs while being cautious about potential harms.

Tumor-Informed Circulating Tumor DNA for Minimal Residual Disease Detection in the Management of Colorectal Cancer.

PURPOSE: Recurrence after curative-intent treatment occurs in 20%-50% of patients with stage II-IV colorectal cancer (CRC), underscoring the need for early detection of minimal residual disease (MRD) using circulating tumor DNA (ctDNA). Here, we examined the pattern of use of a tumor-informed ctDNA assay in CRC MRD monitoring in routine clinical practice at Mayo Clinic, Rochester. METHODS: We conducted a retrospective analysis of health records of patients with CRC who had at least one tumor-informed ctDNA assay from May 2019 through July 1, 2022. Recurrence was defined as radiographic evidence of disease. Descriptive characteristics of the cohort, ctDNA results, and subsequent interventions were recorded. RESULTS: Of the 120 patients included, the median age at diagnosis was 67 years, 46% were female, and 94% were White. At diagnosis, 10 patients had stage I, 23 stage II, 60 stage III, and 25 stage IV disease. Of 476 ctDNA assays performed, 70% were performed in patients who had recurrent disease most commonly to monitor the effectiveness of therapeutic interventions and 16% resulted in a change in clinical decision making. There were 110 recurrences identified in 62 patients, as some patients experienced more than one recurrence over time. Compared with serum carcinoembryonic antigen levels, ctDNA results correlated better with radiologic imaging. CONCLUSION: Routine ctDNA monitoring for MRD detection has been adopted in clinical practice; however, 84% of ctDNA assays performed did not result in a change in clinical management. This suggests the need for further clinical research data to guide routine clinical use of ctDNA MRD testing in CRC.

Early vs conventional onset pancreatic ductal adenocarcinoma: analysis of surgical and oncologic outcomes in patients undergoing curative intent resection.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) impacts patients in their 60s, but its incidence in younger patients is increasing. We hypothesize that younger patients may have worse oncologic outcomes. METHODS: Patients who underwent curative pancreatic resection for PDAC between January 2011 and December 2021 at a single institution were analyzed. Early-onset pancreatic cancer (EOPC) was defined as pancreatic cancer diagnosed in patients ≤50 years. Clinical and survival outcomes were compared between EOPC and Conventional Onset Pancreas Cancer (COPC). RESULTS: A total of 1133 patients were identified, 65 (5.7%) were EOPC. Preoperative patient characteristics including sex, smoking status, alcohol habitus, diabetes mellitus, CA 19-9, and neoadjuvant therapy were similar between EOPC and COPC (p > 0.05). EOPC patients were more likely non-white (p = 0.03), had lower ASA scores (p = 0.02) and larger median tumor size (33 vs 28 mm, p = 0.04), but had similar pathological stages and rate of R0 resections (p > 0.05). Postoperative outcomes were similar (p > 0.05). There was no statistically significant difference in overall (HR 0.93, CI 0.64, 1.33; p = 0.68) or recurrence free (HR 1.05, CI 0.75, 1.48; p = 0.77) survival between the EOPC and COPC after adjusting for significant factors. CONCLUSION: Patients with EOPC who underwent surgical resection had similar oncological outcomes compared to patients with COPC.

Supply and demand of hepatopancreatobiliary surgeons in the United States.

BACKGROUND: Hepatopancreatobiliary (HPB) surgery requires specialized training and adequate case volumes to maintain procedural proficiency and optimal outcomes. Studies of individual HPB surgeon supply related to annual HPB case demand are sparse. This study assesses the supply and demand of the HPB surgical workforce in the United States (US). METHODS: The National Inpatient Sample (NIS) was queried from 1998-2019 to estimate the number of HPB procedures performed. To approximate the number of HPB surgeons, models based on previous HPB workforce publications were employed. We then calculated the number of HPB surgeons needed to maintain volume-outcome thresholds at current reported levels of centralization. RESULTS: In 2019, approximately 37,335 patients underwent inpatient HPB procedures in the US, while an estimated 905-1191 HPB surgeons were practicing. Assuming 50% centralization and an optimal volume-outcome threshold of 24 HPB cases-per-year, only 778 HPB surgeons were needed. Without adjustment in centralization, by 2030 there will be a demand of fewer than 12 annual cases per HPB surgeon. CONCLUSION: The current supply of HPB surgeons may exceed demand in the United States. Without alteration in training pathways or improved care centralization, by 2030, there will be insufficient HPB case volume per surgeon to maintain published volume-outcome standards.

An APRI+ALBI Based Multivariable Model as Preoperative Predictor for Posthepatectomy Liver Failure.

OBJECTIVE AND BACKGROUND: Clinically significant posthepatectomy liver failure (PHLF B+C) remains the main cause of mortality after major hepatic resection. This study aimed to establish an APRI+ALBI, aspartate aminotransferase to platelet ratio (APRI) combined with albumin-bilirubin grade (ALBI), based multivariable model (MVM) to predict PHLF and compare its performance to indocyanine green clearance (ICG-R15 or ICG-PDR) and albumin-ICG evaluation (ALICE). METHODS: 12,056 patients from the National Surgical Quality Improvement Program (NSQIP) database were used to generate a MVM to predict PHLF B+C. The model was determined using stepwise backwards elimination. Performance of the model was tested using receiver operating characteristic curve analysis and validated in an international cohort of 2,525 patients. In 620 patients, the APRI+ALBI MVM, trained in the NSQIP cohort, was compared with MVM's based on other liver function tests (ICG clearance, ALICE) by comparing the areas under the curve (AUC). RESULTS: A MVM including APRI+ALBI, age, sex, tumor type and extent of resection was found to predict PHLF B+C with an AUC of 0.77, with comparable performance in the validation cohort (AUC 0.74). In direct comparison with other MVM's based on more expensive and time-consuming liver function tests (ICG clearance, ALICE), the APRI+ALBI MVM demonstrated equal predictive potential for PHLF B+C. A smartphone application for calculation of the APRI+ALBI MVM was designed. CONCLUSION: Risk assessment via the APRI+ALBI MVM for PHLF B+C increases preoperative predictive accuracy and represents an universally available and cost-effective risk assessment prior to hepatectomy, facilitated by a freely available smartphone app.

Oncologic Outcomes of Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Highly Selected Patients with Metastatic Pancreatic Ductal Adenocarcinoma.

BACKGROUND: Peritoneal metastases (PM) from pancreatic ductal adenocarcinoma (PDAC) are currently treated with palliative systemic chemotherapy alone, with unsatisfactory results. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) may provide an oncologic benefit for highly selected patients. PATIENTS AND METHODS: Patients with PDAC and isolated PM who completed ≥ 6 months of systemic chemotherapy with objective response between 2017 and 2022 were retrospectively reviewed. All patients met the inclusion/exclusion criteria as per our previously published PDAC CRS/HIPEC protocol. Patients who underwent CRS/HIPEC were compared with matched patients who underwent systemic therapy alone. Overall survival (OS) from diagnosis of PM and progression-free survival (PFS) from CRS/HIPEC was evaluated. RESULTS: In total, 61 patients met the inclusion criteria: 38 underwent systemic therapy alone and 23 CRS/HIPEC. There were no differences in baseline prognostic factors, including age, sex, tumor size, tumor location, anatomic resectability, or serum cancer antigen (CA) 19-9 (p > 0.05). Median OS from PM diagnosis in patients who underwent systemic therapy alone was 19 months with 1, 2, and 3 year OS of 81%, 31%, and 8%, respectively. In contrast, median OS from PM diagnosis in patients who underwent CRS/HIPEC was 41 months with improved 1, 2, and 3 year OS of 91%, 66%, and 59%, respectively (p = 0.002). In the 21 patients who achieved complete cytoreduction (CC-0), no adjuvant therapy was administered and the median PFS was 17 months. CONCLUSIONS: CRS/HIPEC in highly selected patients with PDAC and PM results in promising oncologic outcomes that are unlikely to be achieved with systemic chemotherapy alone. Further investigation is warranted and ongoing (NCT04858009).

Accuracy of DOTATATE PET imaging in the preoperative planning of small bowel neuroendocrine tumor resection.

BACKGROUND AND OBJECTIVES: We assessed the accuracy of preoperative gallium-68 DOTA-Tyr3-octreotate (DOTATATE) positron emission tomography (PET) imaging in estimating multifocality and nodal metastases of small bowel neuroendocrine tumors (sbNETs). METHODS: A multicenter analysis was performed on patients with sbNETs who underwent preoperative DOTATATE PET imaging and surgical resection, with manual palpation of the entire length of the small bowel, between January 2016 and August 2022. Preoperative imaging reports and blinded secondary imaging reviews were compared to the final postoperative pathology reports. Descriptive statistics were applied. RESULTS: One-hundred and four patients met inclusion criteria. Pathology showed 53 (51%) patients had multifocal sbNETs and 96 (92%) had nodal metastases. The original preoperative DOTATATE PET imaging identified multifocal sbNET in 28 (27%) patients and lymph node (LN) metastases in 80 (77%) patients. Based on original radiology reports, sensitivity for multifocal sbNET identification was 45%, specificity was 92%, positive predictive value (PPV) was 86%, and negative predictive value (NPV) was 62%. For the identification of LN metastases, sensitivity was 82%, specificity was 88%, PPV was 99%, and NPV was 29%. CONCLUSIONS: Although DOTATATE PET imaging is specific and relatively accurate, sensitivity and NPV are insufficient to guide surgical planning. Preoperative use should not replace open palpation to identify additional synchronous lesions or to omit regional lymphadenectomy.

Quality of Life and Gastrointestinal Symptoms in Long-term Survivors of Pancreatic Cancer Following Pancreatoduodenectomy.

OBJECTIVE: To describe long-term quality of life (QOL) and gastrointestinal (GI) symptoms in patients who underwent pancreatoduodenectomy for pancreatic cancer in the modern era. SUMMARY AND BACKGROUND DATA: As advances in pancreatic cancer management improve outcomes, it is essential to assess long-term patient reported outcomes after surgery. METHODS: Patients who underwent curative intent pancreatoduodenectomy for pancreatic cancer between 1/2011-6/2019 from a single-center were identified. Patients alive ≥3 years after surgery were considered long-term survivors (LTS). LTS who were alive in 6/2022 received a 55-question survey to assess their QOL (EORTC-QLQ-C30) and GI symptoms (EORTC-PAN26 and Problem Areas in Diabetes Questionnaire). Responses were compared against population norms. Clinicodemographic characteristics in LTS vs non-LTS and survey completion were compared. RESULTS: Six-hundred and seventy-two patients underwent pancreatoduodenectomy for pancreatic cancer; 340 were long-term survivors. One-hundred and thirty-seven patients of the 238 eligible to complete the survey responded (response rate: 58%). Compared to the US general population, long-term survivors reported significantly higher QOL (75 vs 64; P <0.001), less nausea/vomiting, pain, dyspnea, insomnia, appetite loss, and constipation, but more diarrhea (all P <0.001). Most patients (n=136/137, 99%) reported experiencing postoperative GI symptoms related to pancreatic insufficiency (n=71/135, 53%), reflux (n=61/135, 45%), delayed gastric emptying (n=31/136, 23%). Most patients (n=113/136, 83%) reported that digestive symptoms overall had little to no impact on QOL, and 91% (n=124/136) would undergo surgery again. CONCLUSIONS: Despite known long-term complications following pancreatoduodenectomy, cancer survivors appear to have excellent QOL. Specific long-term gastrointestinal symptoms data should be utilized for preoperative education and follow-up planning.

Survival and Symptomatic Relief After Cytoreductive Hepatectomy for Neuroendocrine Tumor Liver Metastases: Long-Term Follow-up Evaluation of More Than 500 Patients.

BACKGROUND: Distant metastases are the strongest predictor of poor prognosis for patients with neuroendocrine tumors (NETs). Cytoreductive hepatectomy (CRH) can relieve symptoms of hormonal excess and prolong survival for patients with liver metastases (NETLMs), but long-term outcomes are poorly characterized. METHODS: This retrospective single-institution analysis analyzed patients who underwent CRH for well-differentiated NETLMs from 2000 to 2020. Kaplan-Meier analysis estimated symptom-free interval and overall and progression-free survival. Multivariable Cox regression analysis evaluated factors associated with survival. RESULTS: The inclusion criteria were met by 546 patients. The most common primary sites were the small intestine (n = 279) and the pancreas (n = 194). Simultaneous primary tumor resection was performed for 60 % of the cases. Major hepatectomy comprised 27% of the cases, but this rate decreased during the study period (p < 0.001). Major complications occurred in 20%, and the 90-day mortality rate was 1.6%. Functional disease was present in 37 %, and symptomatic relief was achieved in 96%. The median symptom-free interval was 41 months (62 months after complete cytoreduction and 21 months with gross residual disease) (p = 0.021). The median overall survival was 122 months, and progression-free survival was 17 months. In the multivariable analysis, worse overall survival was associated with age, pancreatic primary tumor, Ki-67, number and size of lesions, and extrahepatic metastases, with Ki-67 as the strongest predictor (odds ratio [OR], 1.90 for Ki-67 [3-20%; p = 0.018] and OR, 4.25 for Ki-67 [>20%; p < 0.001]). CONCLUSION: The study showed that CRH for NETLMs is associated with low perioperative morbidity and mortality and excellent overall survival, although the majority will experience recurrence/progression. For patients with functional tumors, CRH can provide durable symptomatic relief.

Checking Our Blind Spots: Examining Characteristics of Interviewees Versus Matriculants to a Hepatopancreatobiliary Surgical Fellowship Program.

OBJECTIVE: Racial and gender biases exist within academic surgery; bias negatively impacts patient care, reimbursement, student training, and staff retention. Few studies have investigated the potential for bias in surgical fellowship recruitment. We aimed to compare the racial and gender diversity at our hepatopancreatobiliary (HPB) surgery fellowship program to nationwide standards. We further aimed to investigate differences in the demographics of resident interviewees versus matriculants to our HPB fellowship. DESIGN: Retrospective review. SETTING: North American HPB fellowship training programs. PARTICIPANTS: Mayo Clinic's HPB surgery fellowship interviewees and North American HPB surgery fellowship graduates from 2013 to 2020. RESULTS: When compared to general surgery residency graduates during the study period (in 2019), a lower proportion of North American HPB surgery fellowship graduates were female (26% HPB fellowship graduates vs. 43.1% residents, p = 0.005), with no difference in proportion of racially under-represented in medicine (rURM) HPB fellowship graduates (10.7%) compared to rURM proportion of general surgery residents nationally (14.5%). There was an upward trend in female representation among North American HPB fellowship graduates from 11% in 2013 to 32% in 2020, but proportions of rURM HPB fellows remained steadily low. When comparing HPB interviewees at our institution to national general surgery residents, no differences were observed in proportions of female (34.4% interviewees vs. 43.1% residents, p = 0.17) or rURM (interviewees = 6.8%, residents = 14.5%, p = 0.09) applicants. Additionally, there was no significant difference between the proportion of female or rURM interviewees and matriculants to our HPB program. CONCLUSIONS: While fewer female graduating surgeons are pursuing HPB fellowship training than male graduates, this gender gap has narrowed over time. In contrast, the national percentage of rURM HPB fellowship graduates has remained low, mirroring stagnant proportions of rURM surgical residency graduates. When comparing HPB fellowship interviewees at our own institution to North American fellowship graduates, we observed similar proportions of female interviewees but lower proportions of rURM interviewees. Locally, these data will drive process change toward more intentional examination of our interview selection process. Nationally, more work is needed to increase the racial diversity of surgical residency and fellowship trainees to best reflect and serve our diverse patient populations.

Yield of Staging Laparoscopy for Pancreatic Cancer in the Modern Era: Analysis of More than 1,000 Consecutive Patients.

BACKGROUND: Accurate staging prior to resection of pancreatic ductal adenocarcinoma (PDAC) is imperative to avoid unnecessary operative morbidity and oncologic futility in patients with occult intra-abdominal distant metastases. We aimed to determine the diagnostic yield of staging laparoscopy (SL) and to identify factors associated with increased risk of positive laparoscopy (PL) in the modern era. STUDY DESIGN: Patients with radiographically localized PDAC who underwent SL from 2017 to 2021 were retrospectively reviewed. The yield of SL was defined as the proportion of patients with PL, including gross metastases and/or positive peritoneal cytology. Factors associated with PL were assessed using univariate analysis and multivariable logistic regression. RESULTS: Of 1,004 patients who underwent SL, 180 (18%) had PL due to gross metastases (n = 140) and/or positive cytology (n = 96). Patients who had neoadjuvant chemotherapy prior to laparoscopy had lower rates of PL (14% vs 22%, p = 0.002). When the analysis was restricted to chemo-naive patients who had concurrent peritoneal lavage performed, 95 of 419 patients (23%) had PL. In multivariable analysis, PL was associated with younger (<60) age, indeterminate extrapancreatic lesions on preoperative imaging, body/tail tumor location, larger tumor size, and elevated serum CA 19-9 (all p < 0.05). Among patients with no indeterminate extrapancreatic lesions on preoperative imaging, the rate of PL ranged from 1.6% in patients with no risk factors to 42% in young patients with large body/tail tumors and elevated serum CA 19-9. CONCLUSIONS: The rate of PL in patients with PDAC remains high in the modern era. SL with peritoneal lavage should be considered for the majority of patients prior to resection, specifically those with high-risk features, and ideally prior to neoadjuvant chemotherapy.

Gastrointestinal Glomus Tumors: A Single Institution, 20-Year Retrospective Study.

INTRODUCTION: Glomus tumors are rare mesenchymal neoplasms composed of cells resembling those of the thermoregulatory glomus body, typically occurring in the skin and superficial soft tissues. Rarely do they occur in the gastrointestinal tract, in particular the stomach, where they have been the subject of case reports and small series. We present our institutional experience with gastrointestinal glomus tumors. METHODS: A retrospective review of all gastrointestinal glomus tumors was conducted across all three Mayo Clinic sites in Minnesota, Arizona, and Florida from 2001 to 2021. Patient characteristics, pathologic findings, imaging features, operative reports, and clinical outcomes were abstracted. Descriptive statistics were utilized to report outcomes. RESULTS: Nine patients with glomus tumors were identified (five men and four women). The median age was 53 [interquartile range (IQR), 44-69] y. Four patients presented with abdominal discomfort, three had anemia or bleeding, and two tumors were incidentally diagnosed. Computed tomography scans identified masses thought to represent gastrointestinal stromal tumors or neuroendocrine tumors in all patients. The tumors were localized to the stomach in all cases, specifically in the gastric antrum. Seven patients underwent preoperative endoscopy, including five with endoscopic ultrasonography. Endoscopic biopsies were interpreted as glomus tumors (n = 3), neuroendocrine tumors (n = 2), and nondiagnostic (n = 2). All patients underwent open (n = 3) or minimally invasive (n = 6) margin-negative resection by wedge resection (n = 5) or distal gastrectomy (n = 4). No nodal metastases were identified radiographically or on pathologic examination. The median tumor size was 2.5 [IQR 1.3-3.4] cm. All tumors showed at least in part typical glomus tumor morphology and smooth muscle actin expression. Aberrant synaptophysin expression was present in the two tumors initially classified as NET. Using the current WHO criteria, tumors were classified as histologically malignant (n = 1) and of "uncertain malignant potential" (n = 8). At a median follow-up of 15 [IQR 1-56] mo, all patients were asymptomatic and without recurrence. Two patients died of unrelated causes. No patients received adjuvant therapies. CONCLUSIONS: Our 20-year, single institution, 3-site experience with resected gastrointestinal glomus tumors suggests the rarity, predisposition to involve the gastric antrum, and potentially an indolent clinical behavior of many of these tumors. Long-term follow-up is warranted as some previously reported gastric glomus tumors have metastasized, including cases lacking morphologic evidence of malignancy. Surgical resection, with minimally invasive wedge resection alone, is likely sufficient for the management of most gastric glomus tumors.