The microbial composition of pancreatic ductal adenocarcinoma: A systematic review of 16S rRNA gene sequencing.

BACKGROUND: Pancreatic cancer, specifically pancreatic ductal adenocarcinoma (PDAC), continues to pose a significant clinical and scientific challenge. The most significant finding of recent years is that PDAC tumours harbour their specific microbiome, which differs amongst tumour entities and is distinct from healthy tissue. This review aims to evaluate and summarise all PDAC studies that have used the next-generation technique, 16S rRNA gene amplicon sequencing within each bodily compartment. As well as establishing a causal relationship between PDAC and the microbiome. MATERIALS AND METHODS: This systematic review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. A comprehensive search strategy was designed, and 1727 studies were analysed. RESULTS: In total, 38 studies were selected for qualitative analysis and summarised significant PDAC bacterial signatures. Despite the growing amount of data provided, we are not able to state a universal 16S rRNA gene microbial signature that can be used for PDAC screening. This is most certainly due to the heterogeneity of the presentation of results, lack of available datasets and the intrinsic selection bias between studies. CONCLUSION: Several key studies have begun to shed light on causality and the influence the microbiome constituents and their produced metabolites could play in tumorigenesis and influencing outcomes. The challenge in this field is to shape the available microbial data into targetable signatures. Making sequenced data readily available is critical, coupled with the coordinated standardisation of data and the need for consensus guidelines in studies investigating the microbiome in PDAC.

Involvement of the Gut Microbiome in the Local and Systemic Immune Response to Pancreatic Ductal Adenocarcinoma.

The systemic and local immunosuppression exhibited by pancreatic ductal adenocarcinoma (PDAC) contributes significantly to its aggressive nature. There is a need for a greater understanding of the mechanisms behind this profound immune evasion, which makes it one of the most challenging malignancies to treat and thus one of the leading causes of cancer death worldwide. The gut microbiome is now thought to be the largest immune organ in the body and has been shown to play an important role in multiple immune-mediated diseases. By summarizing the current literature, this review examines the mechanisms by which the gut microbiome may modulate the immune response to PDAC. Evidence suggests that the gut microbiome can alter immune cell populations both in the peripheral blood and within the tumour itself in PDAC patients. In addition, evidence suggests that the gut microbiome influences the composition of the PDAC tumour microbiome, which exerts a local effect on PDAC tumour immune infiltration. Put together, this promotes the gut microbiome as a promising route for future therapies to improve immune responses in PDAC patients.

Long-term Outcomes following Resection of Adenocarcinoma Arising from Intraductal Papillary Mucinous Neoplasm (A-IPMN) versus Pancreatic Ductal Adenocarcinoma (PDAC): A Propensity-score Matched Analysis.

OBJECTIVE: The aim of the present study was to compare long-term post-resection oncological outcomes between A-IPMN and PDAC. SUMMARY BACKGROUND DATA: Knowledge of long term oncological outcomes (e.g recurrence and survival data) comparing between adenocarcinoma arising from intraductal papillary mucinous neoplasms (A-IPMN) and pancreatic ductal adenocarcinoma (PDAC) is scarce. METHODS: Patients undergoing pancreatic resection (2010-2020) for A-IPMN were identified retrospectively from 18 academic pancreatic centres and compared with PDAC patients from the same time-period. Propensity-score matching (PSM) was performed and survival and recurrence were compared between A-IPMN and PDAC. RESULTS: 459 A-IPMN patients (median age,70; M:F,250:209) were compared with 476 PDAC patients (median age,69; M:F,262:214). A-IPMN patients had lower T-stage, lymphovascular invasion (51.4%vs. 75.6%), perineural invasion (55.8%vs. 71.2%), lymph node positivity (47.3vs. 72.3%) and R1 resection (38.6%vs. 56.3%) compared to PDAC(P<0.001). The median survival and time-to-recurrence for A-IPMN versus PDAC were 39.0 versus19.5months (P<0.001) and 33.1 versus 14.8months (P<0.001), respectively (median follow-up,78 vs.73 months). Ten-year overall survival for A-IPMN was 34.6%(27/78) and PDAC was 9%(6/67). A-IPMN had higher rates of peritoneal (23.0 vs. 9.1%, P<0.001) and lung recurrence (27.8% vs. 15.6%, P<0.001) but lower rates of locoregional recurrence (39.7% vs. 57.8%; P<0.001). Matched analysis demonstrated inferior overall survival (P=0.005), inferior disease-free survival (P=0.003) and higher locoregional recurrence (P<0.001) in PDAC compared to A-IPMN but no significant difference in systemic recurrence rates (P=0.695). CONCLUSIONS: PDACs have inferior survival and higher recurrence rates compared to A-IPMN in matched cohorts. Locoregional recurrence is higher in PDAC but systemic recurrence rates are comparable and constituted by their own distinctive site-specific recurrence patterns.

Comprehensive, long-term evaluation of pancreatic exocrine insufficiency after pancreatoduodenectomy.

AIMS: Treatment of pancreatic exocrine insufficiency (PEI) following pancreatoduodenectomy (PD) improves quality of life, clinical outcomes, and survival. However, diagnosing PEI following PD is challenging owing to the difficulties with current tests and often non-specific symptoms. This work aims to quantify the true rate of long-term PEI in patients following a PD. METHODS: Patients underwent a PEI screen approximately one to two years following PD for oncologic indication, including the 13C Mixed triglyceride breath test (13CMTGT), faecal elastase 1 (FE-1) and the PEI Questionnaire (PEI-Q). Four reviewers with expertise in PEI reviewed the results blinded to other decisions to classify PEI status; disagreements were resolved on consensus. RESULTS: 26 patients were recruited. Of those with valid test results, these were indicative of PEI based on pre-specified thresholds for 60 % (15/25) for the 13CMTGT, 82 % (18/22) for FE-1, and 88 % (22/25) for the PEI-Q. After discussion between reviewers, the consensus PEI prevalence was 81 % (95 % CI: 61-93 %; 21/26), with 50 % (N = 13) classified as having severe, 23 % (N = 6) moderate, and 8 % (N = 2) mild PEI. DISCUSSION: Since no ideal test exists for PEI, this collation of diagnostic modalities and blinded expert review was designed to ascertain the true rate of long-term PEI following PD. This required our cohort to survive a year, travel to hospital, and undergo a period of starvation and PERT hold, and therefore there is likely to be recruitment bias towards fitter, younger patients with less aggressive pathology. Despite this, over 80 % were deemed to have PEI, with over 90 % of these being considered moderate or severe.

Pancreatic exocrine insufficiency after non-pancreatic upper gastrointestinal surgery: meta-analysis.

BACKGROUND: Untreated pancreatic exocrine insufficiency (PEI) results in substantial patient harm. Upper gastrointestinal surgery (bariatric metabolic surgery and oesophagogastric resection) affects the delicate physiology of pancreatic exocrine function and may result in PEI. The aim of this study was to assimilate the literature on incidence, diagnosis, and management of PEI after bariatric metabolic surgery and oesophagogastric resection. METHODS: A systematic review of PubMed, MEDLINE, and Embase databases identified studies investigating PEI after non-pancreatic upper gastrointestinal surgery. Meta-analyses were undertaken for incidence of PEI and benefit of pancreatic enzyme replacement therapy. RESULTS: Among 1620 patients from 24 studies included in quantitative synthesis, 36.0% developed PEI. The incidence of PEI was 23.0 and 50.4% after bariatric metabolic surgery and oesophagogastric resection respectively. Notably, the incidence of PEI was 44% after biliopancreatic diversion with duodenal switch and 66.2% after total gastrectomy. The most common diagnostic test used was faecal elastase 1 (15 of 31 studies), with less than 200 µg/g being diagnostic of PEI. A total of 11 studies considered the management of pancreatic exocrine insufficiency, with 78.6% of patients responding positively to pancreatic enzyme replacement when it was prescribed. CONCLUSION: PEI is common after non-pancreatic upper gastrointestinal surgery and patients may benefit from enzyme replacement therapy.

Pancreatic exocrine insufficiency occurs when enzymes from the pancreas are unable to help digest food. Pancreatic exocrine insufficiency is known to cause disruptive symptoms after gastrointestinal surgery. Although such symptoms are well known after pancreatic surgery, after other gastrointestinal operations, including bariatric metabolic surgery and oesophagogastric cancer resection, pancreatic exocrine insufficiency is often overlooked as a cause of both symptoms and poor nutrition. This study looked at, and combined, all the current evidence on the rate of pancreatic exocrine insufficiency after these operations, the way it is diagnosed, and how it is treated. Pancreatic exocrine insufficiency may be more common than previously thought after bariatric metabolic surgery or oesophagogastric surgery, and clinicians working with these patients should have a low threshold for starting treatment.

Investigating misdiagnosis of suspected cancer among patients undergoing pancreatoduodenectomy: three decades of experience.

BACKGROUND: Diagnostic error can result in pancreatoduodenectomy (PD) being mistakenly performed for benign disease. The aims of this study were to observe the error rate in PD over three decades and identify characteristics of benign disease that can mimic malignancy. METHODS: Patients with a benign histological diagnosis after having PD performed for suspected malignancy between 1988 and 2019 were selected for review. Preoperative clinical features, imaging and pathological samples were reviewed alongside resection specimens to identify features that may have led to misdiagnosis. RESULTS: Over the study period, 1812 patients underwent PD for suspected malignancy and 97 (5.2 %) of these had a final benign diagnosis. The rate of benign cases reduced across the study period. Some 62 patients proceeded to surgery without a preoperative tissue diagnosis; the decision to operate was made upon clinical and radiologic features alone. There were six patients who had a preoperative pathological sample suspicious for malignancy, of which two had autoimmune pancreatitis in the postoperative histology specimen. DISCUSSION: Benign conditions, notably autoimmune and chronic pancreatitis, can mimic malignancy even with the use of EUS-FNA. The results of all available diagnostic modalities should be interpreted by a multidisciplinary team and honest discussions with the patient should follow.

Pancreatic Exocrine Insufficiency and the Gut Microbiome in Pancreatic Cancer: A Target for Future Diagnostic Tests and Therapies?

Pancreatic exocrine insufficiency (PEI) is common amongst pancreatic cancer patients and is associated with poorer treatment outcomes. Pancreatic enzyme replacement therapy (PERT) is known to improve outcomes in pancreatic cancer, but the mechanisms are not fully understood. The aim of this narrative literature review is to summarise the current evidence linking PEI with microbiome dysbiosis, assess how microbiome composition may be impacted by PERT treatment, and look towards possible future diagnostic and therapeutic targets in this area. Early evidence in the literature reveals that there are complex mechanisms by which pancreatic secretions modulate the gut microbiome, so when these are disturbed, as in PEI, gut microbiome dysbiosis occurs. PERT has been shown to return the gut microbiome towards normal, so called rebiosis, in animal studies. Gut microbiome dysbiosis has multiple downstream effects in pancreatic cancer such as modulation of the immune response and the response to chemotherapeutic agents. It therefore represents a possible future target for future therapies. In conclusion, it is likely that the gut microbiome of pancreatic cancer patients with PEI exhibits dysbiosis and that this may potentially be reversible with PERT. However, further human studies are required to determine if this is indeed the case.

Arterial resection during operative management of pancreatic head and uncinate process adenocarcinoma: a systematic review.

Background: Surgical resection is a part of the treatment pathways for the management of pancreatic cancer with arterial involvement. Arterial resection in this context is however not widely supported due to the paucity and diversity of the reported evidence in the literature. The aim of this systematic review is the presentation and analysis of the current evidence in the field. Methods: A systematic literature search of PubMed, MEDLINE and the Cochrane Library was performed for eligible studies, following the PRISMA guidelines. Information on baseline characteristics, peri-operative outcomes, survival outcomes and histopathological findings were extracted for pooling and analysis. Results: Eight studies with a total of 170 patients were included in the analysis. One hundred and thirty-five patients had a pancreaticoduodenectomy (PD) and 35 had a total pancreatectomy (TP) with arterial resection. Perioperative morbidity was 43.5% and mortality was 4.5%. Median overall survival (OS) was 12.7 months (range, 10.5-22.2 months). Overall 3- and 5-year survival for this cohort was reported at 6.6% (range, 0-42.4%) and 3.3% (range, 0-6.6%) respectively. Resection margins were clear (R0) in a median of 75% of patients. Only a median of 45% of patients received neo-adjuvant chemotherapy. Conclusions: Arterial resection can be performed with an acceptable peri-operative morbidity and mortality. However, survival outcomes are still not convincing and future efforts should concentrate on patient and disease biology selection.

Resection of isolated liver oligometastatic disease in pancreatic ductal adenocarcinoma: Is there a survival benefit? A systematic review.

BACKGROUND: Presence of liver metastatic disease in pancreatic ductal adenocarcinoma (PDAC), either synchronous or metachronous after pancreatic resection, is a terminal diagnosis that warrants management with palliative intent as per all international practice guidelines. However, there is an increasing interest on any potential value of surgical treatment of isolated oligometastatic disease in selected cases. AIM: To present the published evidence on surgical management of PDAC liver metastases, synchronous and metachronous, and compare the outcomes of these treatments to the current standard of care. METHODS: A systematic review was performed in line with the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines to compare the outcomes of both synchronous and metachronous liver metastases resection to standard care. RESULTS: 356 studies were identified, 31 studies underwent full-text review and of these 10 were suitable for inclusion. When synchronous resection of liver metastases was compared to standard care, most studies did not demonstrate a survival benefit with the exception of one study that utilised neoadjuvant treatment. However, resection of metachronous disease appeared to confer a survival advantage when compared to treatment with chemotherapy alone. CONCLUSION: A survival benefit may exist in resection of selected cases of metachronous liver oligometastatic PDAC disease, after disease biology has been tested with time and systemic treatment. Any survival benefit is less clear in synchronous cases; however an approach with neoadjuvant treatment and consideration of resection in some selected cases may confer some benefit. Future studies should focus on pathways for selection of cases that may benefit from an aggressive approach.

Low C-reactive Protein and Urea Distinguish Primary Nonfunction From Early Allograft Dysfunction Within 48 Hours of Liver Transplantation.

Primary nonfunction (PNF) is a life-threatening complication of liver transplantation (LT), but in the early postoperative period, it can be difficult to differentiate from early allograft dysfunction (EAD). The aim of this study was to determine if serum biomarkers can distinguish PNF from EAD in the initial 48 h following LT. Materials and Methods: A retrospective study of adult patients that underwent LT between January 2010 and April 2020 was performed. Clinical parameters, absolute values and trends of C-reactive protein (CRP), blood urea, creatinine, liver function tests, platelets, and international normalized ratio in the initial 48 h after LT were compared between the EAD and PNF groups. Results: There were 1937 eligible LTs, with PNF and EAD occurring in 38 (2%) and 503 (26%) patients, respectively. A low serum CRP and urea were associated with PNF. CRP was able to differentiate between the PNF and EAD on postoperative day (POD)1 (20 versus 43 mg/L; P < 0.001) and POD2 (24 versus 77; P < 0.001). The area under the receiver operating characteristic curve (AUROC) of POD2 CRP was 0.770 (95% confidence interval [CI] 0.645-0.895). The urea value on POD2 (5.05 versus 9.0 mmol/L; P = 0.002) and trend of POD2:1 ratio (0.71 versus 1.32 mmol/L; P < 0.001) were significantly different between the groups. The AUROC of the change in urea from POD1 to 2 was 0.765 (95% CI 0.645-0.885). Aspartate transaminase was significantly different between the groups, with an AUROC of 0.884 (95% CI 0.753-1.00) on POD2. Discussion: The biochemical profile immediately following LT can distinguish PNF from EAD; CRP, urea, and aspartate transaminase are more effective than ALT and bilirubin in distinguishing PNF from EAD in the initial postoperative 48 h. Clinicians should consider the values of these markers when making treatment decisions.

Recent Advances in Pancreatic Ductal Adenocarcinoma: Strategies to Optimise the Perioperative Nutritional Status in Pancreatoduodenectomy Patients.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy for which the mainstay of treatment is surgical resection, followed by adjuvant chemotherapy. Patients with PDAC are disproportionately affected by malnutrition, which increases the rate of perioperative morbidity and mortality, as well as reducing the chance of completing adjuvant chemotherapy. This review presents the current evidence for pre-, intra-, and post-operative strategies to improve the nutritional status of PDAC patients. Such preoperative strategies include accurate assessment of nutritional status, diagnosis and appropriate treatment of pancreatic exocrine insufficiency, and prehabilitation. Postoperative interventions include accurate monitoring of nutritional intake and proactive use of supplementary feeding methods, as required. There is early evidence to suggest that perioperative supplementation with immunonutrition and probiotics may be beneficial, but further study and understanding of the underlying mechanism of action are required.

The impact of the COVID-19 pandemic upon pancreatic cancer treatment (CONTACT Study): a UK national observational cohort study.

INTRODUCTION: CONTACT is a national multidisciplinary study assessing the impact of the COVID-19 pandemic upon diagnostic and treatment pathways among patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: The treatment of consecutive patients with newly diagnosed PDAC from a pre-COVID-19 pandemic cohort (07/01/2019-03/03/2019) were compared to a cohort diagnosed during the first wave of the UK pandemic ('COVID' cohort, 16/03/2020-10/05/2020), with 12-month follow-up. RESULTS: Among 984 patients (pre-COVID: n = 483, COVID: n = 501), the COVID cohort was less likely to receive staging investigations other than CT scanning (29.5% vs. 37.2%, p = 0.010). Among patients treated with curative intent, there was a reduction in the proportion of patients recommended surgery (54.5% vs. 76.6%, p = 0.001) and increase in the proportion recommended upfront chemotherapy (45.5% vs. 23.4%, p = 0.002). Among patients on a non-curative pathway, fewer patients were recommended (47.4% vs. 57.3%, p = 0.004) or received palliative anti-cancer therapy (20.5% vs. 26.5%, p = 0.045). Ultimately, fewer patients in the COVID cohort underwent surgical resection (6.4% vs. 9.3%, p = 0.036), whilst more patients received no anti-cancer treatment (69.3% vs. 59.2% p = 0.009). Despite these differences, there was no difference in median overall survival between the COVID and pre-COVID cohorts, (3.5 (IQR 2.8-4.1) vs. 4.4 (IQR 3.6-5.2) months, p = 0.093). CONCLUSION: Pathways for patients with PDAC were significantly disrupted during the first wave of the COVID-19 pandemic, with fewer patients receiving standard treatments. However, no significant impact on survival was discerned.

Ursodeoxycholic acid in the management of symptomatic gallstone disease: systematic review and clinician survey.

BACKGROUND: Symptomatic gallstones are common. Ursodeoxycholic acid (UDCA) is a bile acid that dissolves gallstones. There is increasing interest in UDCA for symptomatic gallstones, particularly in those unfit for surgery. METHOD: A UK clinician survey of use and opinions about UDCA in symptomatic gallstones was performed, assessing clinicians' beliefs and perceptions of UDCA effectiveness. A systematic review was performed in accordance with the PRISMA guidelines. PubMed, MEDLINE, and Embase databases were searched for studies of UDCA for symptomatic gallstones (key terms included 'ursodeoxycholic acid'; 'UDCA'; 'biliary pain'; and 'biliary colic'). Information was assessed by two authors, including bias assessment, with independent review of conflicts. RESULTS: Overall, 102 clinicians completed the survey, and 42 per cent had previous experience of using UDCA. Survey responses demonstrated clinical equipoise surrounding the benefit of UDCA for the management of symptomatic gallstones, with no clear consensus for benefit or non-benefit; however, 95 per cent would start using UDCA if there was a randomized clinical trial (RCT) demonstrating a benefit. Eight studies were included in the review: four RCTs, three prospective studies, and one retrospective study. Seven of eight studies were favourable of UDCA for biliary pain. Outcomes and follow-up times were heterogenous, as well as comparator type, with only four of eight studies comparing with placebo. CONCLUSION: Evidence for UDCA in symptomatic gallstones is scarce and heterogenous. Clinicians currently managing symptomatic gallstone disease are largely unaware of the benefit of UDCA, and there is clinical equipoise surrounding the benefit of UDCA. Level 1 evidence is required by clinicians to support UDCA use in the future.

Relieving Pressure on the Emergency Department with a New Treatment Pathway for Hand Trauma Patients - A Three-Year Experience with 15,539 Patients.

Background: Hand injuries are a significant and rising burden on the Emergency Department (ED), often leading to protracted waiting times for patients awaiting specialist input. To combat this, a new treatment pathway for hand trauma was introduced at our institution to reduce waiting times and pressure on the ED. Methods: The treatment pathway performance using waiting times, length of stay and cost metrics was measured prior to and following the introduction of a new treatment pathway. Results: There were 15,539 patients reviewed in total. After the new pathway had been introduced, the number of assessments in ED significantly reduced (Year 1: 907 [19.9%] vs. Year 2: 422 [7.9%]; p < 0.001), and the proportion of patients who had an operation on the same day that they were assessed significantly increased (69 [1.5%] vs. 403 [7.5%] patients; p < 0.001). The median waiting time from assessment to operation and length of stay also significantly reduced following the introduction of the treatment pathway (Year 1: 53 hours and Year 2: 45 hours; p < 0.001). Conclusions: Our data over 3 years shows that these changes have been maintained and, in some cases, have continued to improve since the introduction of the new treatment pathway. We advocate the use of such an approach for all hand trauma centres worldwide to replicate these improvements in patient care. Level of Evidence: Level III.

Perioperative interventions to reduce pancreatic fistula following pancreatoduodenectomy: meta-analysis.

BACKGROUND: Data on interventions to reduce postoperative pancreatic fistula (POPF) following pancreatoduodenectomy (PD) are conflicting. The aim of this study was to assimilate data from RCTs. METHODS: MEDLINE and Embase databases were searched systematically for RCTs evaluating interventions to reduce all grades of POPF or clinically relevant (CR) POPF after PD. Meta-analysis was undertaken for interventions investigated in multiple studies. A post hoc analysis of negative RCTs assessed whether these had appropriate statistical power. RESULTS: Among 22 interventions (7512 patients, 55 studies), 12 were assessed by multiple studies, and subjected to meta-analysis. Of these, external pancreatic duct drainage was the only intervention associated with reduced rates of both CR-POPF (odds ratio (OR) 0.40, 95 per cent c.i. 0.20 to 0.80) and all-POPF (OR 0.42, 0.25 to 0.70). Ulinastatin was associated with reduced rates of CR-POPF (OR 0.24, 0.06 to 0.93). Invagination (versus duct-to-mucosa) pancreatojejunostomy was associated with reduced rates of all-POPF (OR 0.60, 0.40 to 0.90). Most negative RCTs were found to be underpowered, with post hoc power calculations indicating that interventions would need to reduce the POPF rate to 1 per cent or less in order to achieve 80 per cent power in 16 of 34 (all-POPF) and 19 of 25 (CR-POPF) studies respectively. CONCLUSION: This meta-analysis supports a role for several interventions to reduce POPF after PD. RCTs in this field were often relatively small and underpowered, especially those evaluating CR-POPF.

Influence of body composition measures on chyle leak after oesophagectomy.

Background: Chyle leak (CL) is an infrequent but potentially serious complication of oesophagectomy. Sarcopenia is an increasingly recognised prognostic factor in oesophageal cancer surgery. The aim of this study was to identify the influence of body composition measures on CL following oesophagectomy. Methods: Patients who developed CL after oesophagectomy between January 2006-December 2020 were identified retrospectively from a prospectively maintained dataset. A control group of patients undergoing oesophagectomy, who did not experience chyle leak during the same time period, was also collected. Relationships between CL and demographics, operative factors and body composition measures were investigated as primary outcomes. Risk factors for severe CL were evaluated as a secondary outcome. Results: There were 26 patients who developed a CL following an oesophagectomy. On univariate analysis, preoperative body mass index (BMI) (P=0.001), subcutaneous fat index (P=0.001) and total fat index (P=0.004) were significantly associated with CL. On multivariate analysis, a lower preoperative subcutaneous fat index was a significant independent predictor of CL (P=0.003). Sarcopenia, as an overall measure, was not found to be a significant predictor of developing CLs. No significant predictors of severe CL were identified. Conclusions: A reduced preoperative BMI and body fat composition are risk factors for CL after oesophagectomy. Sarcopenia does not predict either the occurrence or severity of CL. This presents potentially modifiable risk factors for CL after oesophagectomy and emphasises the importance of physiological and nutritional optimisation before oesophagectomy.

Early oral feeding after pancreatoduodenectomy: a systematic review and meta-analysis.

BACKGROUND: The effect of early oral feeding (EOF) after pancreatoduodenectomy (PD) upon perioperative complications and outcomes is unknown, therefore the aim of this systematic review and meta-analysis was to investigate the effect of EOF on clinical outcomes after PD, such as postoperative pancreatic fistula (POPF), delayed gastric emptying (DGE) and length of stay (LOS). METHODS: A systematic review and meta-analysis was performed in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance and assimilated evidence from studies reporting outcomes for patients who received EOF after PD compared to enteral tube feeding (EN) or parenteral nutrition (PN). RESULTS: Four studies reported outcomes after EOF compared to EN/PN after PD and included 553 patients. Meta-analyses showed no difference in rates of CR-POPF (OR 0.74; 95%CI 0.44-1.24; p = 0.25) or DGE (Grade B/C) (OR 0.83; 95%CI 0.31-2.21; p = 0.70). LOS was significantly shorter in the EOF group compared to the EN/PN group (Mean Difference -3.40 days; 95% -6.11-0.70 days; p = 0.01). CONCLUSION: Current available evidence suggests that EOF after PD is not associated with increased risk of DGE, does not exacerbate POPF and appears to reduce length of stay.