Metabolic outcomes in obese mice undergoing one-anastomosis gastric bypass (OAGB) with a long or a short biliopancreatic limb.

One-anastomosis gastric bypass (OAGB) has gained importance as a simple, safe, and effective operation to treat morbid obesity. We previously found that Roux-en-Y gastric bypass surgery with a long compared with a short biliopancreatic limb (BPL) leads to improved weight loss and glucose tolerance in obese mice. However, it is not known whether a long BPL in OAGB surgery also results in beneficial metabolic outcomes. Five-week-old male C57BL/6J mice fed a high-fat diet (HFD) for 8 weeks underwent OAGB surgery with defined BPL lengths (5.5 cm distally of the duodenojejunal junction for short and 9.5 cm for long BPL), or sham surgery combined with caloric restriction. Weight loss, glucose tolerance, obesity-related comorbidities, endocrine effects, gut microbiota, and bile acids were assessed. Total weight loss was independent of the length of the BPL after OAGB surgery. However, a long BPL was associated with lower glucose-stimulated insulin on day 14, and an improved glucose tolerance on day 35 after surgery. Moreover, a long BPL resulted in reduced total cholesterol, while there were no differences in the resolution of metabolic dysfunction-associated steatotic liver disease (MASLD) and adipose tissue inflammation. Tendencies of an attenuated hypothalamic-pituitary-adrenal (HPA) axis and aldosterone were present in the long BPL group. With both the short and long BPL, we found an increase in primary conjugated bile acids (pronounced in long BPL) along with a loss in bacterial Desulfovibrionaceae and Erysipelotrichaceae and simultaneous increase in Akkermansiaceae, Sutterellaceae, and Enterobacteriaceae. In summary, OAGB surgery with a long compared with a short BPL led to similar weight loss, but improved glucose metabolism, lipid, and endocrine outcomes in obese mice, potentially mediated through changes in gut microbiota and related bile acids. Tailoring the BPL length in humans might help to optimize metabolic outcomes after bariatric surgery.NEW & NOTEWORTHY Weight loss following OAGB surgery in obese mice was not influenced by BPL length, but a longer BPL was associated with improved metabolic outcomes, including glucose and lipid homeostasis. These changes could be mediated by bile acids upon altered gut microbiota. Further validation of these findings is required through a randomized human study.

Laparoscopic Roux-Y-gastric bypass versus laparoscopic one-anastomosis gastric bypass for obesity: clinical & metabolic results of a prospective randomized controlled trial.

BACKGROUND: One anastomosis gastric bypass (OAGB) has been proposed as an effective alternative to the current standard procedure in Switzerland, Roux-en-Y gastric bypass (RYGB). Prospective data comparing both procedures are scarce. Therefore, we performed a non-inferiority randomized controlled trial assessing the effectiveness and safety of these 2 operative techniques. METHOD: Eighty patients were randomized 1:1. OAGB consisted of a very long gastric pouch with a 200 cm biliopancreatic limb, RYGB of a 150 cm ante-colic alimentary and a 60 cm biliopancreatic limb, respectively. Primary endpoint was the percent excess weight loss (%EWL) at 12 months after surgery. RESULTS: Mean %EWL at 12 months was 87.9% (SD24.4) in the RYGB group and 104.1% (SD24.6) in the OAGB group (p = 0.006). There was no mortality. The rate of marginal ulcers was higher in patients with OAGB compared to those with RYGB (p = 0.011), while the total number of late complications did not statistically differ between the two groups. Except for the remission of GERD, which was higher in the RYGB group compared to OAGB, there was no difference between the groups regarding the remission of comorbidities. OAGB showed improved glucose control compared to the RYGB after 1 year (p = 0.001). Furthermore, glucagon-like peptide-1 increase was significantly higher in OAGB at 6 weeks (p = 0.041) and 1 year after surgery (p = 0.029). Quality of life improved after both surgeries, without differences between the groups. CONCLUSIONS: %EWL 1 year after surgery was higher in OAGB than in RYGB. A better glycemic control with a higher increase in GLP-1 was observed after OAGB compared to RYGB. TRIAL REGISTRATION: This trial is registered on ClinicalTrials.gov under the identifier NCT02601092.

Incidence and risk factors of symptomatic Petersen's hernias in bariatric and upper gastrointestinal surgery: a systematic review and meta-analysis.

PURPOSE: The aim of this study was to investigate the actual incidence of symptomatic Petersen's hernias (PH) as well as identify risk factors for their occurrence. METHODS: Search was performed in Medline (via PubMed), Web of Science, and Cochrane library, using the keywords "Petersen Or Petersen's AND hernia" and "Internal hernia." Only studies of symptomatic PH were eligible. Fifty-three studies matched our criteria and were included. Risk of bias for each study was independently assessed using the checklist modification by Hoy et al. Analysis was performed using random-effects models, with subsequent subgroup analyses. RESULTS: A total of 81,701 patients were included. Mean time interval from index operation to PH diagnosis was 17.8 months. Total small bowel obstruction (SBO) events at Petersen's site were 737 (0.7%). SBO incidence was significantly higher in patients without defect closure (1.2% vs 0.3%, p < 0.01), but was not significantly affected by anastomosis fashion (retrocolic 0.7% vs antecolic 0.8%, p = 0.99). SBO incidence was also not significantly affected by the surgical approach (laparoscopic = 0.7% vs open = 0.1%, p = 0.18). However, retrocolic anastomosis was found to be associated with marginally, but not significantly, increased SBO rate in patients with Petersen's space closure, compared with the antecolic anastomosis (p = 0.09). CONCLUSION: PH development may occur after any gastric operation with gastrojejunal anastomosis. Contrary to anastomosis fashion and surgical approach, defect closure was demonstrated to significantly reduce SBO incidence. Limitations of this study may include the high heterogeneity and the possible publication bias across the included studies.

The role of surgical treatment in isolated organ recurrence of esophageal cancer-a systematic review of the literature.

BACKGROUND: Despite the improvements in the early detection and treatment of non-metastatic esophageal cancer, more than half of patients undergoing a curative treatment for esophageal cancer will develop recurrence within three years. The prognosis of these patients is poor. However, a wide range in overall survival has been reported, depending on the pattern of recurrence, and no optimal treatment strategy following recurrence has yet been uniformly accepted. AIM: In this article, we aimed to systematically review the literature for the role of surgical resection of metachronous distant metastasis following primary treatment of esophageal cancer. Furthermore, we discuss possible factors that could possibly predict which patients may benefit from a surgical approach. A comprehensive literature search was conducted in PubMed using combinations of keywords. RESULTS: Patients with recurrence may benefit of a multimodality treatment. Regarding the isolated recurrence of esophageal cancer in solid visceral organs, operative intervention has been proposed as a treatment that may offer a survival benefit in an individual basis. No definitive conclusions regarding the potential survival advantage offered by the surgical treatment of solitary recurrent lesions can be drawn. However, recent improvements in surgical treatment and optimization of perioperative management guarantee an acceptable operative risk, making surgical resection of solitary recurrence lesions a considerable therapeutic option. CONCLUSIONS: It can be conferred from the available studies that the surgical treatment of isolated recurrence from esophageal cancer may offer a survival benefit for properly selected patients. Prospective, multicenter studies might be useful to gain a better insight into those factors that affect selection of patients to take benefit from an operative intervention.

Bariatric Surgery and Metabolic Dysfunction-Associated Fatty Liver Disease: a 2022 Update.

Non-alcoholic fatty liver disease (NAFLD) has been recently termed metabolic dysfunction-associated fatty liver disease (MAFLD) to address the strong association with the metabolic syndrome. The prevalence of MAFLD is significantly increased in obese individuals and treatment of obesity is currently the cornerstone of management of MAFLD. Bariatric and metabolic surgery nowadays emerges as a key therapeutic strategy for the treatment of the MAFLD. This review aims to provide an update on the novel studies reporting the outcomes of bariatric surgery on the spectrum of MAFLD, from hepatic steatosis to cirrhosis.

Risk of Reopening of the Mesenteric Defects After Routine Closure in Laparoscopic Roux-en-Y Gastric Bypass: a Single-Centre Experience.

PURPOSE: Small bowel obstruction (SBO) due to internal hernias (IH) is a well-recognised complication after laparoscopic Roux-en-Y gastric bypass (LRYGB). Routine closure of the mesenteric defects (MDs) is recommended to reduce the risk of IH and subsequent SBO. However, data about the rates of reopening of the MDs after LRYGB is scarce. The main aim of this study was to evaluate the risk of reopening of the MDs after routine closure during LRYGB. The secondary objective was to determine any risk factors associated with the reopening of the MDs. METHODS: Data of all patients who underwent reoperations after LRYGB with closure of both MDs between January 2010 and December 2018 were retrospectively reviewed. RESULTS: A total of 162 patients were included. The median time between LRYGB and reoperation was 17 months. At the time of reoperation, both MDs were closed in 83 patients (51.2%); thus, 79 patients (48.8%) presented at least one open MD. The group of patients with preoperative diagnosis of SBO or with recurrent abdominal pain showed significantly higher rates of open Petersen's space compared to the group of patients with other preoperative diagnoses. Preoperative body mass index (BMI) less than 40 kg/m2 at time of LRYGB was associated with a higher risk for an open MD. CONCLUSION: At least one MD reopened in almost half of the patients despite routine closure during LRYGB. Therefore, the status of MDs should be routinely examined during every reoperation after LRYGB and closure of open MDs should be performed.

Intraoperative Patterns of Gastric Microperfusion During Laparoscopic Roux-en-Y Gastric Bypass.

INTRODUCTION: Visible light spectroscopy (VLS) represents a sensitive, non-invasive method to quantify tissue oxygen levels and detect hypoxemia. The aim of this study was to assess the microperfusion patterns of the gastric pouch during laparoscopic Roux-en-Y gastric bypass (LRYGB) using the VLS technique. METHODS: Twenty patients were enrolled. Tissue oxygenation (StO2%) measurements were performed at three different localizations of the gastric wall, prior and after the creation of the gastric pouch, and after the creation of the gastro-jejunostomy. RESULTS: Prior to the creation of the gastric pouch, the lowest StO2% levels were observed at the level of the distal esophagus with a median StO2% of 43 (IQR 40.8-49.5). After the creation of the gastric pouch and after the creation of the gastro-jejunostomy, the lowest StO2% levels were recorded at the level of the His angle with median values of 29% (IQR 20-38.5) and 34.5% (IQR 19-39), respectively. The highest mean StO2 reduction was recorded at the level of the His angle after the creation of the gastric pouch, and it was 18.3% (SD ± 18.1%, p < 0.001). A reduction of StO2% was recorded at all localizations after the formation of the gastro-jejunostomy compared to the beginning of the operation, but the mean differences of the StO2% levels were statistically significant only at the resection line of the pouch and at the His angle (p = 0.044 and p < 0.001, respectively). CONCLUSION: Gastric pouch demonstrates reduction of StO2% during LRYGB. VLS is a useful technique to assess microperfusion patterns of the stomach during LRYGB.

Primary Squamous Cell Carcinoma of Colon and Rectum: A Systematic Review of the Literature.

Background - Objective: Primary colorectal squamous cell carcinoma is an extremely rare neoplasm with an incidence of 0.1 to 0.25 per 1,000 diagnosed colorectal carcinomas.The objective of this study was to evaluate its biological behavior and highlight the role of a surgical approach for its management.MethodsPubMed and Cohrane databases were independently searched (last search: April 10th, 2020) for articles concerning colorectal squamous cell carcinoma in adult population.Results: Seventy-one studies met predefined inclusion criteria and involved 99 patients (54.5% females) with an age of 56.98 ± 12.19 years (mean ± SD). The most frequent site of occurrence was the rectum (63.5%). Open surgery was conducted at 95% of patients, while 21.4% and 30.3% received neoadjuvant and adjuvant therapy respectively.Postoperative complications were developed in 31.3% of patients, while 6.1% died withing the first month following operation. Five-years survival rate was 49.5% (95% CI: 33.7%-63.4%). Female sex (HR: 0.24; 95% CI: 0.11-0.54; p-value: 0.001) and presence of postoperative complications (HR: 4.10; 95%CI: 1.47-1.46; p-value: 0.007) significantly affected the survival.Conclusions Colorectal Squamous Cell Carcinoma is a rare tumor with an aggressive behavior. Surgery is the standard of treatment for the colontumors, while the role of chemoradiotherapy is promising especially for rectal tumors. Further clinical trials are necessary to determine the preferred treatment approach.

Roux-en-Y gastric bypass with a long versus a short biliopancreatic limb improves weight loss and glycemic control in obese mice.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) results in long-term weight loss and reduced obesity related co-morbidities. However, little is known about how the lengths of the biliopancreatic limb (BPL), the alimentary limb (AL), and the common limb (CL) affect weight loss and glucose metabolism. OBJECTIVES: Our aim was to establish a RYGB obese mouse model with defined proportions of the AL and BPL and a constant CL to assess the effects on weight loss,glucose metabolism, and obesity-related co-morbidities. SETTING: In vivo mouse study. METHODS: Six-week-old male C57BL/6J mice fed with a high-fat diet (HFD) underwent bariatric surgery with defined BPL lengths: a very long, long, and short BPL (35%, 25%, and 15% of total bowel length), or sham surgery. The length of the AL was adjusted to achieve the same CL length. Mice were analyzed for weight loss, glycemic control, and obesity-related co-morbidities. RESULTS: Mice undergoing RYGB surgery with a very long BPL had excessive weight loss and mortality and were therefore not further analyzed. Mice with a long BPL showed a significantly increased total weight loss when compared with mice with a short BPL. In addition, a long BPL improved glucose tolerance, particularly early after surgery. A long BPL was also associated with lower triglyceride levels. Resolution of hepatic steatosis and adipose tissue inflammation was, however, not statistically significant. Of note, bariatric surgery dramatically changed gut microbiota, regardless of limb length. CONCLUSION: In obese mice, a long BPL results in enhanced weight loss and improved glucose tolerance. These findings could potentially be translated to humans by tailoring the BPL length according to body weight, obesity-related co-morbidities, and total bowel length of an individual patient.

Long-Term Outcome of Proximal Versus Very-Very Long Limb Roux-en-Y Gastric Bypass: the Roux-Limb to Common Channel Ratio Determines the Long-Term Weight Loss.

BACKGROUND: The influence of the Roux limb (RL) length on weight loss in Roux-en-Y (RYGB)-type gastric bypass procedures is still unclear. This study analyzes the true impact of RL length by comparing the long-term outcomes of proximal RYGB (PRYGB) and very-very long limb RYGB (VVLL-RYGB). METHODS: RL length in PRYGB was 150 cm. In VVLL-RYGB, common channel length was 100 cm. In both groups, biliopancreatic limbs measured 50-60 cm, resulting in equal total alimentary limb lengths. To adjust for pre-operative differences between groups, and to predict the long-term outcome, a mixed model analysis was performed. RESULTS: Two hundred thirty-two patients with VVLL-RYGB (73.7% female, mean age 41.1 ± 10 years, initial BMI 45.8 ± 6.3 kg/m2) and 223 with PRYGB (83.9% female, mean age 38.5 ± 11 years, initial BMI 42.9 ± 4.9 kg/m2) were included. Mean follow-up was 9.4 ± 4 years in VVLL-RYGB and 5.3 ± 1.9 years in PRYGB. After 5 years, mean BMI reduction was 15.7 ± 5.9 kg/m2 in VVLL-RYGB and 11.9 ± 4.1 kg/m2 in PRYGB (p < 0.001), and mean %EWL was 78.3 ± 23.1% and 70.2 ± 23.7% (p = 0.002) with a follow-up rate of 78% and 75.9%, respectively. The mixed model analysis showed a significantly higher weight rebound after PRYGB. Frequency of revisional surgery (i.e., limb length alteration, pouch banding) was similar between VVLL-RYGB and PRYGB (25 vs. 29 revisions, p = 0.463). CONCLUSION: The VVLL-RYGB has a significantly higher long-term BMI reduction and a significantly lower weight rebound. The length of the Roux limb significantly influences long-term outcome.

Short or Long Biliopancreatic Limb Bypass as a Secondary Procedure After Failed Laparoscopic Sleeve Gastrectomy.

PURPOSE: Laparoscopic sleeve gastrectomy (SG) may be associated with long-term problems such as insufficient weight loss or weight regain, persistence or relapse of comorbidities, and gastroesophageal reflux disease (GERD). This study analyzes the outcome of patients that underwent conversion of SG to a gastric bypass procedure. MATERIALS AND METHODS: All patients that underwent conversion from SG to the following four different gastric bypass procedures were analyzed: short biliopancreatic limb (BPL) bypass types such as proximal Roux-en-Y gastric bypass (PRYGB) or type 2 distal Roux-en-Y gastric bypass (type 2 DRYGB) and long BPL types such as long BPL RYGB or one anastomosis gastric bypass (OAGB). RESULTS: Between 2012 and 2016, 52 patients received the following revisional procedures after primary SG: proximal RYGB (n = 12, 23.1%), type 2 DRYGB (n = 8, 15.4%), long BPL RYGB (n = 20, 38.5%), and OAGB (n = 12, 23.1%). The long BPL type procedures (long BPL RYGB, OAGB) resulted in a significant long-term additional %EWL (33.8%; 33.2%) at 3 years. In the PRYGB, the effect lasted only for 2 years. In all patients with GERD and dysphagia as the dominant post-SG symptoms, the conversion to a bypass procedure resulted in the complete resolution of these. CONCLUSION: In case of weight regain or insufficient weight loss after SG, revisional surgery with a long BPL should be considered. The OAGB provides effective additional weight loss, with low morbidity and malnutrition rates, respectively. Conversion to the malabsorptive long BPL RYGB with a total alimentary limb length below 400 cm should be avoided. Patients that suffer primarily from post-SG GERD or dysphagia should undergo conversion to PRYGB.

Revisional Adjustable Gastric Band in Roux-en-Y Gastric Bypass-Is It Worth It?

PURPOSE: A subset of patients undergoing Roux-en-Y gastric bypass (RYGB) presents with either insufficient weight loss or weight regain. Data on the revisional restrictive options including laparoscopic adjustable gastric band (LAGB) is scarce. This study analyzes the mid-term efficacy and safety of LAGB as a revisional procedure after RYGB. METHODS: Data of all patients with revisional LAGB after primary RYGB between January 2011 and May 2019 were retrospectively reviewed. Outcomes included assessment of weight changes, resolution of comorbidities, and early and late complications during the study period. RESULTS: Twenty patients were included. The median Body Mass Index (BMI) before revisional LAGB was 34.8 (interquartile range [IQR] 31.9-38.1) kg/m2. After a median follow-up of 33.5 (IQR 19.5-76.5) months, the median BMI was 28.7 (IQR 26.1-32.2) kg/m2. The median additional Excess Weight Loss (EWL) was 37.6% (IQR 23-44.4), leading to a median total EWL of 79.5% (IQR 54.4-94.6). BMI and EWL post-LAGB improved significantly compared to BMI and EWL pre-LAGB (p<0.001 and p<0.001, respectively). Obstructive sleep apnea syndrome resolved 6 months after LAGB in one patient. Three band deflations occurred during the follow-up. Six patients underwent band removal after a median time of 19 (IQR 15.8-26) months. Overall, thirteen patients underwent a reoperation. There was no loss of follow-up until 5 years. After that, two patients were lost to follow-up. CONCLUSION: LAGB may be a salvage option after failed RYGB. However, the high rate of revisions after secondary LAGB needs to be taken into consideration.

The Impact of the COVID-19 Pandemic on Bariatric Surgery: Results from a Worldwide Survey.

BACKGROUND: The ongoing "coronavirus disease 19" (COVID-19) pandemic has had a strong effect on the delivery of surgical care worldwide. Elective surgeries have been canceled or delayed in order to reallocate resources to the treatment of COVID-19 patients. Currently, the impact of the COVID-19 pandemic on bariatric and metabolic surgical practice remains unclear. METHODS: An internet-based online survey was performed among bariatric surgeons worldwide. The survey was sent to bariatric surgeons via the International Bariatric Club Facebook group and by electronic mail via the International Federation for the Surgery of Obesity and metabolic disorders (IFSO) secretariat to members of the associated national IFSO societies. RESULTS: One hundred sixty-nine (n = 169) bariatric surgeons participated in the survey. The majority of the respondents postponed preoperative upper gastrointestinal tract endoscopies, appointments in the outpatient clinic and bariatric operations. Most surgeons performed video calls for follow-up appointments instead of meeting the patients in the outpatient clinics. Laparoscopy was still the preferred treatment for surgical emergencies, but a trend towards conservative treatment of acute appendicitis and acute cholecystitis was shown. Rapid preoperative COVID-19 testing availability was poor; therefore, routine screening of emergency bariatric cases was not widely provided. A wide variance occurred regarding precautions and personal protection equipment among the participants. CONCLUSION: The COVID-19 pandemic showed a strong impact on bariatric surgical practice regarding surgical and outpatient planning as well as personnel management. Coordinated effort from the national bariatric societies should focus on strict implementation of the current recommendations regarding precaution measures and personal protection equipment. Further studies should evaluate how this impact will evolve in the near future.

Revisional Surgery for Insufficient Loss or Regain of Weight After Roux-en-Y Gastric Bypass: Biliopancreatic Limb Length Matters.

INTRODUCTION: Weight regain after laparoscopic Roux-en-Y gastric bypass (RYGB) occurs in up to 35% of patients. Revisional surgery may be applied. Conversion from RYGB to a long biliopancreatic limb (BPL) RYGB is a potential option for revisional surgery and short-term results are promising. METHODS: All patients who underwent conversion to long BPL RYGB due to weight loss failure, defined as excess weight loss (EWL) < 50% or body mass index (BMI) > 35 kg/m2, were assessed. Proximal RYGB or very very long limb RYGB (VVLL RYGB) was modified by shortening of the total alimentary limb length (TALL) to create a long BPL. RESULTS: A total of 28 patients received revisional surgery from either PRYGB (n = 22) or VVLL RYGB (n = 6). Mean age at operation was 45.3 ± 10.4 years, with 78% females. Mean prerevisional BMI was 41.7 ± 4.4 kg/m2. Mean time to revision was 76.5 ± 38.5 months. Limb lengths were 150 cm (95% CI 133-156 cm) for RL and 100 cm (95% CI 97-113 cm) for CC, thus providing a total median alimentary limb length of 250 (95% CI 238-260 cm). Additional %EWL and TWL improved significantly in long-term. Five years postoperatively, all patients (n = 9) had an EWL% > 50%. Six patients (21.4%) required reoperation due to severe malnutrition during the postoperative course. CONCLUSION: Conversion from RYGB to BPL RYGB leads to significant additional weight loss in the long term. However, the morbidity is relevant, especially severe protein malnutrition and the frequency of revisional surgery. Therefore, this type of surgery should not be done routinely.

Low anterior resection syndrome (LARS) in ovarian cancer patients - A multi-centre comparative cohort study.

BACKGROUND: Low anterior resection syndrome (LARS) is a common functional disorder after low anterior resection impacting the quality of life. Data on LARS derives nearly exclusively from rectal cancer studies. Therefore, the study was designed to assess LARS in advanced epithelial ovarian cancer (EOC) patients, who underwent rectal resection and to compare it with a female rectal cancer cohort. MATERIAL AND METHODS: A cross-sectional multi-centre analysis was performed on female patients suffering from either rectal or EOC who received a low anterior resection as part of their therapy regimen. None of the patients received pre- or postoperative radiotherapy. LARS was defined by using the validated LARS score and its severity was divided into "no", "minor" and "major LARS". RESULTS: In total, 125 female patients (44.8% (n = 56) EOC vs. 55.2% (n = 69) rectal cancer patients) met the final inclusion criteria and were retrospectively analyzed. Baseline characteristics were comparable between the groups. Median follow-up was 22 (IQR 12-56) months. In total, 30.4% (n = 38) of the patient group reported bowel dysfunction after surgery. Rates of LARS were not significantly different between EOC and rectal cancer patients (major LARS 16.1% (n = 9) vs. 15.9% (n = 11); minor LARS 17.9% (n = 10) vs. 11.6% (n = 8); p = 0.984). The time interval between surgery and final assessment had no impact on the postoperative bowel function (p = 0.820). CONCLUSION: LARS is a frequent and highly underreported postoperative disorder in EOC patients who require cytoreductive surgery with rectal resection. The functional outcome is comparable to female patients with rectal cancer who underwent low anterior resection without receiving radiotherapy.

Clinicopathological data and treatment modalities for pancreatic vipomas: a systematic review.

PURPOSE: Vasoactive intestinal peptide (VIP) secreting tumor (VIPoma) constitutes a rare functional neuroendocrine tumor that most often originates from pancreatic islet cells and presents as a sporadic, solitary neoplasm of the pancreas. The purpose of this study was to systematically review the literature of pancreatic VIPomas and report clinicopathologic data and treatment modalities for this rare entity. METHODS: A systematic literature search was performed. The reviewed clinical series and case reports were included if they reported surgical treatment and also analyzed oncological outcomes on individual patients. Data extraction was performed using a standard registry pro-forma. RESULTS: The search resulted in 53 case reports and 2 case series including 65 patients in total. Median age reported was 54 years. The predominant pancreatic location was the pancreatic tail. The most common clinical symptom was watery diarrhea. Serum VIP levels were remarkably elevated in all patients. Distal pancreatectomy with or without splenectomy was the most commonly applied surgical procedure. Overall survival associated with pancreatic VIPoma was 67.7%, recurrence rate 40.4% and relevant median disease-free interval was 16 months. CONCLUSIONS: VIPomas are functional tumors that secrete excessive amounts of VIP. Clinically, production of VIP causes refractory watery diarrhea, hypokalemia and achlorydria. As far as diagnosis is concerned, elevated VIP plasma levels are required. Moreover, the majority of VIPomas are malignant or have already metastasized on diagnosis. Despite recent research on the therapeutic strategies against pancreatic VIPoma, surgical resection appears as the only potentially curative approach.