The occurrence of Enterococcus faecium and faecalis Is significantly associated With anastomotic leakage After pancreaticoduodenectomy

Surgical prophylaxis in pancreatoduodenectomy: Is cephalosporin still the drug of choice in patients with biliary stents in situ?

BACKGROUND

Universal surgical prophylaxis for pancreatoduodenectomy (PD) is practiced, with cephalosporins recommended in most guidelines. Recent studies suggest piperacillin-tazobactam (PTZ) prophylaxis in biliary-stented patients is superior in preventing surgical site infections (SSIs). This study aims to refine surgical prophylaxis recommendations based on the local microbial profile and evaluate the clinical outcomes of biliary-stented compared with non-stented patients.

METHODS

This was a retrospective study of all consecutive PD patients at Singapore General Hospital between January 2013 to December 2019. The primary outcome was post-operative SSI rates. Secondary outcomes included rates of ceftriaxone-resistant Klebsiella pneumoniae, Escherichia coli, and Enterococcus species from intraoperative bile cultures and 30-day mortality.

RESULTS

There were 130 biliary-stented and 211 non-stented patients included. Majority of biliary-stented patients received ceftriaxone ± metronidazole prophylaxis (83/130, 63.8 %) while 30/130 (23.8 %) received PTZ. Most non-stented patients received ceftriaxone ± metronidazole prophylaxis (163/211, 77.3 %). Between biliary-stented and non-stented patients, post-operative SSIs (40.8 % vs 38.4 %, p = 0.662), and 30-day mortality rates (1.5 % vs 1.4 %, p = 1.000) were comparable. The adjusted odds of post-operative SSIs was significantly lower in biliary-stented patients prescribed PTZ as compared to non-PTZ prophylaxis (0.29, 95 % CI (0.10-0.79), p = 0.015). Ceftriaxone-resistant Klebsiella spp. and/or Escherichia coli (27.6 % vs 3.8 %, p < 0.001) as well as Enterococcus species (46.1 % vs 11.5 %, p < 0.001), were more prevalent in intraoperative bile cultures of biliary-stented patients, while frequencies in non-stented patients were low.

CONCLUSION

PTZ prophylaxis effectively reduced SSIs in stented patients post-pancreatoduodenectomy. Based on the local microbial profile, ceftriaxone prophylaxis may be used for prophylaxis in non-stented patients.

Perioperative pancreaticoduodenectomy management strategy focusing on postoperative early drain colonization

PURPOSE

Pancreatoduodenectomy (PD) is a highly invasive procedure. Intra-abdominal infections and pancreatic fistulas are strongly correlated complications. In the present study, we identified the risk factors for postoperative early drain colonization (POEDC) and established a perioperative management strategy.

METHODS

A total of 205 patients who underwent pancreatoduodenectomy were included in the study. POEDC was defined as a positive drain fluid culture before postoperative day (POD) 4. We retrospectively investigated the correlation between POEDC, postoperative outcomes, and clinical factors.

RESULTS

POEDC was observed in 26 patients (12.6%) with poor postoperative outcomes, including pancreatic fistulas (P < 0.001). A multivariate analysis demonstrated a correlation between these postoperative outcomes and the age (P = 0.002), body mass index (BMI) (P = 0.002), procalcitonin (PCT) level (P < 0.001), and drain amylase level on POD 1 (P = 0.032). Enterococcus was detected most frequently, being found in 15 patients.

CONCLUSION

We observed a strong correlation between POEDC and poor postoperative outcomes. The BMI, age, and PCT and drain amylase level on POD 1 should be considered POEDC risk factors, with the need to propose an antibiotic perioperative strategy. POEDC control may represent the key to improving postoperative outcomes after PD.

Revealing the role of early peripancreatic bacterial contamination and Enterococcus faecalis in pancreatic fistula development after pancreaticoduodenectomy: Implications for useful antibiotic prophylaxis-An observational cohort study

BACKGROUND

Peripancreatic bacterial contamination (PBC) is a critical factor contributing to the development of clinically relevant postoperative pancreatic fistula (CR-POPF) following pancreaticoduodenectomy (PD). Controlling pathogenic bacteria is essential in preventing CR-POPF; however, the precise relationship between specific bacteria and CR-POPF remains unclear. This study aimed to investigate the relationship between PBC and CR-POPF after PD, with a focus on identifying potentially causative bacteria.

METHODS

This prospective observational study enrolled 370 patients who underwent PD. Microbial cultures were routinely collected from peripancreatic drain fluid on postoperative days (PODs) 1, 3, and 6. Predictive factors for CR-POPF and the bacteria involved in PBC were investigated.

RESULTS

CR-POPF occurred in 86 (23.2%) patients. In multivariate analysis, PBC on POD1 (Odds ratio [OR] = 3.59; P = 0.005) was one of the main independent predictive factors for CR-POPF, while prophylactic use of antibiotics other than piperacillin/tazobactam independently influenced PBC on POD1 (OR = 2.95; P = 0.010). Notably, Enterococcus spp., particularly Enterococcus faecalis, were significantly isolated from PBC in patients with CR-POPF compared to those without CR-POPF on PODs 1 and 3 (P < 0.001), and they displayed high resistance to all cephalosporins.

CONCLUSIONS

Early PBC plays a pivotal role in the development of CR-POPF following PD. Prophylactic antibiotic administration, specifically targeting Enterococcus faecalis, may effectively mitigate early PBC and subsequently reduce the risk of CR-POPF. This research sheds light on the importance of bacterial control strategies in preventing CR-POPF after PD.

Prophylactic Antibiotic Duration and Infectious Complications in Pancreatoduodenectomy Patients With Biliary Stents: Opportunity for De-escalation

OBJECTIVE

The aim of this study was to compare infectious complications in pancreatoduodenectomy (PD) patients with biliary stents treated with short, medium, or long durations of prophylactic antibiotics.

BACKGROUND

Pre-existing biliary stents have historically been associated with higher infection risk after PD. Patients are administered prophylactic antibiotics, but the optimal duration remains unknown.

METHODS

This single-institution retrospective cohort study included consecutive PD patients from October 2016 to April 2022. Antibiotics were continued past the operative dose per surgeon discretion. Infection rates were compared by short (≤24 h), medium (>24 but ≤96 h), and long (>96 h) duration antibiotics. Multivariable regression analysis was performed to evaluate associations with a primary composite outcome of wound infection, organ-space infection, sepsis, or cholangitis.

RESULTS

Among 542 PD patients, 310 patients (57%) had biliary stents. The composite outcome occurred in 28% (34/122) short, 25% (27/108) medium, and 29% (23/80) long-duration ( P =0.824) antibiotic patients. There were no differences in other infection rates or mortality. On multivariable analysis, antibiotic duration was not associated with infection rate. Only postoperative pancreatic fistula (odds ratio 33.1, P <0.001) and male sex (odds ratio 1.9, P =0.028) were associated with the composite outcome.

CONCLUSIONS

Among 310 PD patients with biliary stents, long-duration prophylactic antibiotics were associated with similar composite infection rates to short and medium durations but were used almost twice as often in high-risk patients. These findings may represent an opportunity to de-escalate antibiotic coverage and promote risk-stratified antibiotic stewardship in stented patients by aligning antibiotic duration with risk-stratified pancreatectomy clinical pathways.

Antibiotic prophylaxis with piperacillin-tazobactam reduces organ/space surgical site infection after pancreaticoduodenectomy: a retrospective and propensity score-matched analysis

BACKGROUND

The occurrence of surgical site infection (SSI) after pancreaticoduodenectomy (PD) is still relatively high. The aim of this retrospective study is to evaluate the efficacy of piperacillin-tazobactam as perioperative prophylactic antibiotic on organ/space SSI for patients underwent PD.

METHODS

Four hundred seven consecutive patients who underwent PD between January 2018 and December 2022 were enrolled and analyzed retrospectively. The univariate and multivariate analysis were used to identify independent risk factors of organ/space SSI. Postoperative complications were compared between the two groups according to the use of prophylactic antibiotics by a ratio of 1:1 propensity score-matched (PSM) analysis.

RESULTS

Based on perioperative prophylactic antibiotic use, all 407 patients were divided into the ceftriaxone group (n = 192, 47.2%) and piperacillin-tazobactam group (n = 215, 52.8%). The rate of organ/space SSI was 31.2% with the choice of perioperative antibiotics (OR = 2.837, 95%CI = 1.802-4.465, P < 0.01) as one of independent risk factors. After PSM, there were similar baseline characteristics among the groups. Meanwhile, the piperacillin-tazobactam group had a significant lower rate of organ/space SSI compared to the ceftriaxone group both before and after PSM(P < 0.05).

CONCLUSIONS

The adoption of piperacillin-tazobactam as perioperative prophylaxis for patients underwent PD reduced organ/space SSI significantly.

Association of cephalosporin resistance in intraoperative biliary cultures with surgical site infections in patients undergoing pancreaticoduodenectomy. A retrospective cohort study

BACKGROUND

The aim of this study was to assess the incidence of bacterobilia at the time of a pancreaticoduodenectomy (PD) and the association of resistant bacteria in bile to surgical site infections (SSI).

METHODS

This was a retrospective cohort study including patients undergoing PD in a single center between May 2016 and October 2020. Data of preoperative biliary drainage (PBD), intraoperative biliary cultures (IBC) and postoperative complications were analysed to assess the risk factors for resistant bacteria in IBC and SSIs.

RESULTS

Of 361 patients included, 254 (70%) had undergone PBD. Second-generation cephalosporin resistant bacteria were found in IBC of 183 (64%) of all the patients. PBD was the only risk factor for second-generation cephalosporin resistance. The risk for second-generation cephalosporin resistance was more than 20-fold in patients with PBD [n = 170/254 (67%) (OR 22.58 (95% CI, 9.61-53.01), p < 0.001)] compared to patients who did not have PBD (n = 13/107 (12%)). Also, if the time between PBD and surgery was 2 months or more the second-generation cephalosporin resistance in IBC increased the risk for SSIs (OR 4.14 (95% CI, 1.18-14.51), p = 0.027).

CONCLUSION

The second-generation cephalosporin resistance in IBC is common in patients who have undergone PBD. Broad-spectrum antibiotics in prophylaxis may be beneficial for these patients.

Clinical usefulness of routinely performed drain fluid cultures after pancreaticoduodenectomy. A new ally to predict patients' outcomes?

BACKGROUND

Previous studies showed that bacterial contamination of surgical drains was associated with higher morbidity and mortality following pancreaticoduodenectomy (PD). However, there is still no agreement on the routine use of fluid drainage cultures in the management of patients underwent PD. Therefore, we aimed to clarify the role of surgical drain bacterial contamination in predicting patients' postoperative course.

METHOD

Single-centre study including patients underwent PD at Humanitas Research Hospital (2010-2021). Preoperative, intraoperative and postoperative data were collected. Routinely performed fluid drain cultures on postoperative day (POD) 5 were analyzed and compared among patients throughout the cohort.

RESULTS

A total of 825 patients were analyzed. Bacterial contamination of surgical drains was observed in 420 (50.9 %) patients and it was found to be associated with a higher rate of B/C grade pancreatic fistula (POPF) (P < 0.001), Clavien-Dindo≥3 (P < 0.001), 30-day mortality (P = 0.011), wound infection (P < 0.001), relaparotomies (P = 0.003) and greater length of hospital stay (LOS) (P < 0.001). Also, E. coli surgical drain contamination was demonstrated to double the risk of B/C grade POPF development (OR = 1.628, 95 % IC = 1.009-2.625, P = 0.046). Finally, preoperative biliary drainage (OR = 2.474, 95 % IC = 1.855-3.298, P < 0.001), age ≥75 years old (OR = 1.492, 95 % IC = 1.077-2.067, P = 0.016) and isolated Roux-en-Y pancreaticojejunostomy (OR = 1.639, 95 % IC = 1.229-2.188, P < 0.001) were identified as risk factors for surgical drains bacterial contamination.

CONCLUSION

Bacterial contamination of surgical drains predicts the development of B/C grade POPF and other major complications after PD. Therefore, we suggest the routine use of fluid drain cultures following PD.

Non-Surgical Interventions for the Prevention of Clinically Relevant Postoperative Pancreatic Fistula-A Narrative Review

Clinically relevant postoperative pancreatic fistula (CR-POPF) is the leading cause of morbidity and mortality after pancreatic surgery. Post-pancreatectomy acute pancreatitis (PPAP) has been increasingly understood as a precursor and exacerbator of CR-POPF. No longer believed to be the consequence of surgical technique, the solution to preventing CR-POPF may lie instead in non-surgical, mainly pharmacological interventions. Five databases were searched, identifying eight pharmacological preventative strategies, including neoadjuvant therapy, somatostatin and its analogues, antibiotics, analgesia, corticosteroids, protease inhibitors, miscellaneous interventions with few reports, and combination strategies. Two further non-surgical interventions studied were nutrition and fluids. New potential interventions were also identified from related surgical and experimental contexts. Given the varied efficacy reported for these interventions, numerous opportunities for clarifying this heterogeneity remain. By reducing CR-POPF, patients may avoid morbid sequelae, experience shorter hospital stays, and ensure timely delivery of adjuvant therapy, overall aiding survival where prognosis, particularly in pancreatic cancer patients, is poor.

Study of risk factors for delayed gastric emptying after partial pancretoduodenectomy

INTRODUCTION

Delayed gastric emptying is one of the most frequent complications after pancreatoduodenectomy.

METHODS

We performed an analysis of risk factors for delayed gastric emptying on a prospective database of 390 patients operated on between 2013 and 2021. A comparative retrospective study was carried out between patients with and without delayed gastric emptying and subsequently a study of risk factors for delayed gastric emptying using univariate and multivariate logistic regression models.

RESULTS

The incidence of delayed gastric emptying in the overall series was 28%. The morbidity of the group was 63%, and postoperative mortality was 3.1%. Focusing on delayed gastric emptying, the median age (73 years vs 68 years, P < 0.001) and preoperative creatinine (75 vs 65.5, P < 0.001) were higher in the group with this complication. The study of risk factors showed that age over 60 years (P = 0.002) and pancreatic fistula (P < 0.001) were risk factors for delayed gastric emptying.

CONCLUSION

The presence of pancreatic fistula is confirmed as a risk factor for slow gastric emptying after pancreaticoduodenectomy. In addition, age over 60 years is shown to be a risk factor for slow gastric emptying.

New understanding of gut microbiota and colorectal anastomosis leak: A collaborative review of the current concepts

Anastomotic leak (AL) is a life-threatening postoperative complication following colorectal surgery, which has not decreased over time. Until now, no specific risk factors or surgical technique could be targeted to improve anastomotic healing. In the past decade, gut microbiota dysbiosis has been recognized to contribute to AL, but the exact effects are still vague. In this context, interpretation of the mechanisms underlying how the gut microbiota contributes to AL is significant for improving patients' outcomes. This review concentrates on novel findings to explain how the gut microbiota of patients with AL are altered, how the AL-specific pathogen colonizes and is enriched on the anastomosis site, and how these pathogens conduct their tissue breakdown effects. We build up a framework between the gut microbiota and AL on three levels. Firstly, factors that shape the gut microbiota profiles in patients who developed AL after colorectal surgery include preoperative intervention and surgical factors. Secondly, AL-specific pathogenic or collagenase bacteria adhere to the intestinal mucosa and defend against host clearance, including the interaction between bacterial adhesion and host extracellular matrix (ECM), the biofilm formation, and the weakened host commercial bacterial resistance. Thirdly, we interpret the potential mechanisms of pathogen-induced poor anastomotic healing.

Drain fluid biomarkers for prediction and diagnosis of clinically relevant postoperative pancreatic fistula: A narrative review

Clinically relevant postoperative pancreatic fistula (CR-POPF) has continued to compromise patient recovery post-pancreatectomy despite decades of research seeking to improve risk prediction and diagnosis. The current diagnostic criteria for CR-POPF requires elevated drain fluid amylase to present alongside POPF-related complications including infection, haemorrhage and organ failure. These worrying sequelae necessitate earlier and easily obtainable biomarkers capable of reflecting evolving CR-POPF. Drain fluid has recently emerged as a promising source of biomarkers as it is derived from the pancreas and hence, capable of reflecting its postoperative condition. The present review aims to summarise the current knowledge of CR-POPF drain fluid biomarkers and identify gaps in the field to invigorate future research in this critical area of clinical need. These findings may provide robust diagnostic alternatives for CR-POPF and hence, to clarify their clinical utility require further reports detailing their diagnostic and/or predictive accuracy.

Polymicrobial periprosthetic joint infection and osteomyelitis of the tibia with circumferential abscess and skin ulcer 11 years after total knee arthroplasty

We report the case of a 71-year-old woman with a skin ulcer derived from an abscess around the tibia. The abscess resulted in periprosthetic joint infection and osteomyelitis 11 years after total knee arthroplasty. The first symptom was a skin ulcer of the lower leg. Magnetic resonance imaging revealed a circumferential mass around the proximal tibia. A skin biopsy taken around the ulcer showed thrombosis and degenerated collagen. Contrast-enhanced computed tomography showed a circumferential mass around the proximal tibia with ring enhancement. Biopsies of the skin ulcer and circumferential mass showed an abscess caused by Enterococcus faecium and methicillin-resistant Staphylococcus epidermis. We conducted debridement of the abscess, a gastrocnemius flap and split-thickness skin grafting and a 2-stage revision of the total knee component with a hinged prosthesis. Two years later, the infection did not reoccur and the patient can walk without a cane. This case is unique as abscess around proximal tibia caused necrotic skin ulcer and appearance of abscess was fibrous and different from typical bacterial abscesses containing pus or fluid. Contrast-enhanced computed tomography was effective for differentiation of the pathological condition.

A Comprehensive Review of the Current and Future Role of the Microbiome in Pancreatic Ductal Adenocarcinoma

Simple Summary

This review summarizes the current literature related to the microbiome and pancreatic ductal adenocarcinoma (PDAC). The aim of this review is to explore the current role of the microbiome in the disease process, screening/diagnostics and to postulate the future role with regards to therapeutic strategies including chemotherapy, immunotherapy and surgery. We further explore the future of microbiome modulation (faecal microbiome transplants, bacterial consortiums, anti-microbials and probiotics), their applications and how we can improve the future of microbiome modulation in a bid to improve PDAC outcomes.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is expected to become the second most common cause of cancer death in the USA by 2030, yet progress continues to lag behind that of other cancers, with only 9% of patients surviving beyond 5 years. Long-term survivorship of PDAC and improving survival has, until recently, escaped our understanding. One recent frontier in the cancer field is the microbiome. The microbiome collectively refers to the extensive community of bacteria and fungi that colonise us. It is estimated that there is one to ten prokaryotic cells for each human somatic cell, yet, the significance of this community in health and disease has, until recently, been overlooked. This review examines the role of the microbiome in PDAC and how it may alter survival outcomes. We evaluate the possibility of employing microbiomic signatures as biomarkers of PDAC. Ultimately this review analyses whether the microbiome may be amenable to targeting and consequently altering the natural history of PDAC.

The association between bacterobilia and the risk of postoperative complications following pancreaticoduodenectomy

BACKGROUND

Pre-operative biliary bacterial colonisation (bacterobilia) is considered a risk factor for infectious complications after pancreaticoduodenectomy (PD). This study aimed to investigate the role of the PD biliary microbiome grown in the development of post-PD complications.

METHODS

In a retrospective study of 162 consecutive patients undergoing PD (2008-2018), intra-operative bile cultures were analyzed and sensitivities compared to pre-anesthetic antibiotics and thirty-day post-surgery complications.

RESULTS

Bacterobilia was present in 136 patients (84%). Most bile cultures grew bacteria resistant to pre-operative antibiotics (n = 112, 82%). Patients with bacterobilia had significantly higher rates of major complication than patients without (P = 0.017), as well as higher rates of surgical-site infections (SSI) (P = 0.010). Patients with negative bile cultures (n = 26) had significantly lower rates of major complication and SSI than those growing sensitive (n = 24) or non-sensitive (n = 112) bacteria (major complication P = 0.029 and SSI P = 0.011).

CONCLUSION

Positive bile cultures were associated with a higher incidence of major complications and SSI. Patients with sterile bile cultures had the lowest risk of post-operative complications and efforts to reduce rates of bacterobilia, such as limitation of biliary instrumentation, should be considered. Sensitivity to antibiotics had no effect upon the rate of post-operative complications, but this may reflect low cohort numbers.

The Role of Targeted Versus Standard Antibiotic Prophylaxis in Pancreatoduodenectomy in Reducing Postoperative Infectious Complications: A Systematic Review and Meta-analysis

INTRODUCTION

Infectious complications are common after pancreatoduodenectomy, which in turn are associated with preoperative biliary drainage. Current guidelines recommend a first-generation cephalosporin as perioperative antibiotic prophylaxis. However, some studies support the use of targeted antibiotics. The aim of this systematic review and meta-analysis is to evaluate the role of prophylactic targeted antibiotics compared to standard antibiotics in reducing postoperative infections after pancreatoduodenectomy.

METHODS

A search from MEDLINE, EMBASE, and Cochrane library from 1946 to July 2020 was conducted. Studies were included if they compared targeted antibiotics with standard perioperative antibiotics while including outcome data on surgical site infections (SSI). Targeted therapy was defined as perioperative antibiotics targeting organisms prevalent in bile instrumentation or by culture data obtained from the patient or institution. Outcomes assessed were the rate of SSIs and their microbiology profile. Analyses included demographic data, perioperative antibiotics, postoperative outcomes including microbiology data, and meta-analysis was performed where applicable.

RESULTS

Seven studies were included, with a total of 849 patients undergoing pancreatoduodenectomy. Targeted antibiotics were associated with a significantly lower rate of postoperative SSI compared to standard antibiotic therapy [21.1% vs 41.9%; risk ratios (RR) 0.55, 95% confidence interval 0.37-0.81]. Wound/incisional site infections and organ space infections were lower in patients receiving targeted antibiotic prophylaxis (RR 0.33, P = 0.0002 and RR 0.54, P = 0.0004, respectively). Enterococcus species were the most common bacteria reported.

CONCLUSION

There was a significant reduction in overall SSI rates when targeted antibiotics was used. Current standard antibiotic prophylaxis is inadequate in covering microbes prevalent in postoperative infections developing after pancreatoduodenectomy.

Current Insights: The Impact of Gut Microbiota on Postoperative Complications in Visceral Surgery-A Narrative Review

Postoperative complications are a major problem occurring in up to 50% of patients undergoing major abdominal surgery. Occurrence of postoperative complications is associated with a significantly higher morbidity and mortality in affected patients. The most common postoperative complications are caused by an infectious genesis and include anastomotic leakage in case of gastrointestinal anastomosis and surgical site infections. Recent research highlighted the importance of gut microbiota in health and disease. It is plausible that the gut microbiota also plays a pivotal role in the development of postoperative complications. This narrative review critically summarizes results of recent research in this particular field. The review evaluates the role of gut microbiota alteration in postoperative complications, including postoperative ileus, anastomotic leakage, and surgical site infections in visceral surgery. We tried to put a special focus on a potential diagnostic value of pre- and post-operative gut microbiota sampling showing that recent data are inhomogeneous to identify a high-risk microbial profile for development of postoperative complications.

Enterococcal Infections the First Year after Liver Transplantation-A Prospective Cohort Study

This study aimed to investigate the incidence of enterococcal infections and determine risk factors associated with enterococcal bloodstream infection (BSI) within the first year post-liver transplantation (LTx). We included 321 adult liver transplant recipients transplanted from 2011 to 2019 in a prospective cohort study. Cumulative incidence of enterococcal infections and risk factors associated with BSI were investigated in a competing risk model and time-updated Cox models, respectively. A total of 223 enterococcal infections were identified in 89 recipients. The cumulative incidences of first enterococcal infection and first enterococcal BSI were 28% (95% CI (23-33)) and 11% (CI (7-14)), respectively. Risk factors associated with enterococcal BSI were previous infections in the biliary tract (HR, 33; CI (15-74); p < 0.001), peritoneum (HR, 8.1; CI (3-23); p < 0.001) or surgical site (HR, 5.5; CI (1.4-22); p = 0.02), recipient age (HR per 10 years increase, 1.2; CI (1.03-1.6); p = 0.03), and cold ischemia time (HR per one hour increase, 1.2; CI (1.1-1.3); p < 0.01). Enterococcal infections are highly prevalent the first year post-LTx, and recipients with enterococcal infections in the biliary tract, peritoneum, or surgical site are at increased risk of BSI. These findings may have implications for the choice of empiric antibiotics early post-LTx.

Different Biliary Microbial Flora Influence Type of Complications after Pancreaticoduodenectomy: A Single Center Retrospective Analysis

BACKGROUND

Bacterobilia is associated with postoperative morbidity after pancreaticoduodenectomy (PD), mostly due to infectious complications. The aim of this study was to investigate the prevalence of bacteria species isolated from intraoperative biliary cultures, and related complications after PD.

METHODS

An ANOVA test was used to assess the prevalence of isolated bacterial species and postoperative complications. The odds ratio was computed to evaluate the association between biliary cultures and each complication, Endoscopic Retrograde CholangioPancreatography (ERCP) and each complication, ERCP and biliary cultures, Delayed Gastric Emptying (DGE) and Postoperative Pancreatic Fistula (POPF).

RESULTS

Positive biliary cultures were found in 162/244 (66%) PDs. Different prevalences of polymicrobial biliary culture were detected in patients with postoperative complications. In SSIs, a significant prevalence of biliary culture positive for E. coli, Klebsiella pneumoniæ and Enterococcus fæcalis (p < 0.001) was detected. Prevalences of polymicrobial biliary cultures with Escherichia coli, Klebsiella pneumoniæ, Enterococcus fæcalis and Enterococcus fæcium were significantly associated with POPF (p < 0.001). Biliary culture positive for Escherichia coli, Enterococcus fæcalis and Enterococcus fæcium showed a higher prevalence of intra-abdominal collection and DGE (p < 0.001). Notably, Escherichia coli was significantly associated with DGE as a unique complication (OR = 2.94 (1.30-6.70); p < 0.01).

CONCLUSIONS

Specific prevalences of polymicrobial bacterobilia are associated with major complications, while monomicrobial Escherichia coli bacterobilia is associated with DGE as a unique complication after PD.

The diagnostic value of C-reactive protein for predicting pancreatic fistula following pancreatoduodenectomy

INTRODUCTION

Pancreaticoduodenectomy is the preferred treatment of neoplasms in the pancreas and duodenum. Postoperative pancreatic fistula is a critical complication. A potential predictive marker is C-reactive protein. This retrospective study examined the predictive value of C-reactive protein as a marker for development of postoperative pancreatic fistulas.

METHODS

All patients who had a pancreaticoduodenectomy from 1 January 2015 to 31 December 2019, were included. Levels of the biomarker and linear trajectory were determined for postoperative days one to four. Univariate analysis was used to identify predictive variables for a postoperative pancreatic fistula. Receiver operating characteristics curves, specificity, and sensitivity were calculated.

RESULTS

Five hundred and fifty-two patients underwent pancreaticoduodenectomy. C-reactive protein level greater than 121.5mg/L on the third postoperative day and an increase in C-reactive protein level between the first and fourth postoperative days, greater than 21.7mg/L, seemed to be reliable predictors. For Grade C postoperative pancreatic fistulas, increases in C-reactive protein, greater than 40.6ml/L the first four postoperative days, had a sensitivity of 100%. White blood cell count did not have similar reliability in predicting postoperative pancreatic fistulas.

CONCLUSION

Our findings indicate that small rises in C-reactive protein during the first postoperative days after pancreaticoduodenectomy are associated with an increased risk of developing postoperative pancreatic fistula.

High incidence of postoperative infections after pancreaticoduodenectomy: A need for perioperative anti-infectious strategies

OBJECTIVES

Postoperative infections occur frequently after pancreaticoduodenectomy, especially in patients with bile colonization. Recommendations for perioperative anti-infectious treatment are lacking, and clinical practice is heterogenous. We have analyzed the effects of bile colonization and antibiotic prophylaxis on postoperative infection rates, types and therapeutic consequences.

METHODS

Retrospective observational study in patients undergoing pancreaticoduodenectomy with intraoperative bile culture. Data on postoperative infections and non-infectious complications, bile cultures and antibiotic prophylaxis adequacy to biliary bacteria were collected.

RESULTS

Among 129 patients, 53% had a positive bile culture and 23% had received appropriate antibiotic prophylaxis. Postoperative documented infection rate was over 40% in patients with or without bile colonization, but antibiotic therapy was more frequent in positive bile culture patients (77% vs. 57%, P=0,008). The median duration of antibiotic therapy was 11 days and included a broad-spectrum molecule in 42% of cases. Two-thirds of documented postoperative infections involved one or more bacteria isolated in bile cultures, which was associated with a higher complication rate. While bile culture yielded Gram-negative bacilli (57%) and Gram-positive cocci (43%), fungal microorganisms were scarce. Adequate preoperative antibiotic prophylaxis according to bile culture was not associated with reduced infectious or non-infectious complication rates.

CONCLUSION

Patients undergoing pancreaticoduodenectomy experience a high rate of postoperative infections, often involving bacteria from perioperative bile culture when positive, with no preventive effect of an adequate preoperative antibiotic prophylaxis. Increased postoperative complications in patients with bile colonization may render necessary a perioperative antibiotic treatment targeting bile microorganisms. Further prospective studies are needed to improve the anti-infectious strategy in these patients.

Review of Colonic Anastomotic Leakage and Prevention Methods

Although surgeries involving anastomosis are relatively common, anastomotic leakages are potentially deadly complications of colorectal surgeries due to increased risk of morbidity and mortality. As a result of the potentially fatal effects of anastomotic leakages, a myriad of techniques and treatments have been developed to treat these unfortunate cases. In order to better understand the steps taken to treat this complication, we have created a composite review involving some of the current and best treatments for colonic anastomotic leakage that are available. The aim of this article is to present a background review of colonic anastomotic leakage, as well as current strategies to prevent and treat this condition, for a broader audience, including scientist, engineers, and especially biomedical engineers.

New insight into the association between bile infection and clinically relevant pancreatic fistula in patients undergoing pancreatoduodenectomy

BACKGROUND

The association between bacterial infection and clinically relevant postoperative pancreatic fistula (CR-POPF) after pancreatoduodenectomy (PD) has not been fully elucidated.

METHODS

Microbiological data for intraoperative bile culture (BC) and drain culture on postoperative day 4 (DC) were collected. The study population was classified into the following three groups: P1 (positive BC and DC), P2 (positive BC and negative DC), and N (negative BC). A total of 209 patients (P1: 38, P2: 72, and N: 99) who underwent PD between May 2013 and May 2018 met the inclusion criteria of the study.

RESULTS

The rate of CR-POPF was significantly higher in the P1 group (34.2%) than in the P2 (12.5%; P = .007) and N groups (14.1%; P = .008). Between P1 and P2 groups, a significant difference was observed in the proportion of Enterococcus faecalis grown in BC (42.1% vs 4.2%; P < .001). Multivariable logistic regression analysis showed that the presence of E faecalis in bile was independently associated with CR-POPF.

CONCLUSIONS

The detection of both bile and postoperative abdominal fluid infections can be more accurate in predicting CR-POPF. Furthermore, the presence of E faecalis in bile may serve as a novel surrogate marker for CR-POPF.

Comparative genetics of Enterococcus faecalis intestinal tissue isolates before and after surgery in a rat model of colon anastomosis

We have recently demonstrated that collagenolytic Enterococcus faecalis plays a key and causative role in the pathogenesis of anastomotic leak, an uncommon but potentially lethal complication characterized by disruption of the intestinal wound following segmental removal of the colon (resection) and its reconnection (anastomosis). Here we hypothesized that comparative genetic analysis of E. faecalis isolates present at the anastomotic wound site before and after surgery would shed insight into the mechanisms by which collagenolytic strains are selected for and predominate at sites of anastomotic disruption. Whole genome optical mapping of four pairs of isolates from rat colonic tissue obtained following surgical resection (herein named “pre-op” isolates) and then 6 days later from the anastomotic site (herein named “post-op” isolates) demonstrated that the isolates with higher collagenolytic activity formed a distinct cluster. In order to perform analysis at a deeper level, a single pair of E. faecalis isolates (16A pre-op and 16A post-op) was selected for whole genome sequencing and assembled using a hybrid assembly algorithm. Comparative genomics demonstrated absence of multiple gene clusters, notably a pathogenicity island in the post-op isolate. No differences were found in the fsr-gelE-sprE genes (EF1817-1822) responsible for regulation and production of collagenolytic activity. Analysis of unique genes among the 16A pre-op and post-op isolates revealed the predominance of transporter systems-related genes in the pre-op isolate and phage-related and hydrolytic enzyme-encoding genes in the post-op isolate. Despite genetic differences observed between pre-op and post-op isolates, the precise genetic determinants responsible for their differential expression of collagenolytic activity remains unknown.

Involvement of the Commensal Organism Bacillus subtilis in the Pathogenesis of Anastomotic Leak

Background: It is now well established that microbes play a key and causative role in the pathogenesis of anastomotic leak. Yet, in patients, determining whether a cultured pathogen retrieved from an anastomotic leak site is a cause or a consequence of the complication remains a challenge. The aim of this study was to test a methodology to invoke causality between a retrieved microbe from a leak site and its role in anastomotic leak. Methods: The commensal organism Bacillus subtilis was isolated from an esophagojejunostomy leak site in a 35-year-old patient with a CDH1 mutation after a prophylactic gastrectomy whose body mass index (BMI) was 35 kg/m². The organism was screened for its ability to degrade collagen, shift human recombinant matrix metalloprotease-9 (MMP9) to its active form, and induce a clinical anastomotic leak when introduced to anastomotic tissues of mice fed their standard diet (SD) of chow or an obesogenic Western-type diet (WD). Results: The Bacillus subtilis strain retrieved from the anastomotic leak site displayed a high degree of collagenolytic activity and was able to activate human MMP9 consistent with other pathogens expressing this characteristic "leak phenotype." Exposure of the Bacillus subtilis to the anastomotic tissues of obese mice fed a WD led to dehiscence of the anastomosis, abscess formation with peritonitis, and mortality in 50% of mice (3/6). When anastomotic healing was evaluated by a validated anastomotic healing score (AHS), substantially worse healing was observed (i.e., higher AHS) in WD-fed mice exposed to Bacillus subtilis compared to SD-fed mice (analysis of variance [ANOVA], p = 0.0006). Conclusions: Microbial strains obtained from patients' anastomotic leak sites can be evaluated for their pathogenic in the leak process by assessing their ability to produce collagenase, activate MMP9 and cause clinical leaks in mice fed a WD. These studies may aid in identifying those bacterial strains that play a causal role in patients with an anastomotic leak.

Low-fat/high-fibre diet prehabilitation improves anastomotic healing via the microbiome: an experimental model

BACKGROUND

Both obesity and the presence of collagenolytic bacterial strains (Enterococcus faecalis) can increase the risk of anastomotic leak. The aim of this study was to determine whether mice chronically fed a high-fat Western-type diet (WD) develop anastomotic leak in association with altered microbiota, and whether this can be mitigated by a short course of standard chow diet (SD; low fat/high fibre) before surgery.

METHODS

Male C57BL/6 mice were assigned to either SD or an obesogenic WD for 6 weeks followed by preoperative antibiotics and colonic anastomosis. Microbiota were analysed longitudinally after operation and correlated with healing using an established anastomotic healing score. In reiterative experiments, mice fed a WD for 6 weeks were exposed to a SD for 2, 4 and 6 days before colonic surgery, and anastomotic healing and colonic microbiota analysed.

RESULTS

Compared with SD-fed mice, WD-fed mice demonstrated an increased risk of anastomotic leak, with a bloom in the abundance of Enterococcus in lumen and expelled stool (65-90 per cent for WD versus 4-15 per cent for SD; P = 0·010 for lumen, P = 0·013 for stool). Microbiota of SD-fed mice, but not those fed WD, were restored to their preoperative composition after surgery. Anastomotic healing was significantly improved when WD-fed mice were exposed to a SD diet for 2 days before antibiotics and surgery (P < 0·001).

CONCLUSION

The adverse effects of chronic feeding of a WD on the microbiota and anastomotic healing can be prevented by a short course of SD in mice. Surgical relevance Worldwide, enhanced recovery programmes have developed into standards of care that reduce major complications after surgery, such as surgical-site infections and anastomotic leak. A complementary effort termed prehabilitation includes preoperative approaches such as smoking cessation, exercise and dietary modification. This study investigated whether a short course of dietary prehabilitation in the form of a low-fat/high-fibre composition can reverse the adverse effect of a high-fat Western-type diet on anastomotic healing in mice. Intake of a Western-type diet had a major adverse effect on both the intestinal microbiome and anastomotic healing following colonic anastomosis in mice. This could be reversed when mice received a low-fat/high-fibre diet before operation. Taken together, these data suggest that dietary modifications before major surgery can improve surgical outcomes via their effects on the intestinal microbiome.

Correlation between invasive microbiota in margin-surrounding mucosa and anastomotic healing in patients with colorectal cancer

BACKGROUND

Impaired anastomotic healing is one of the major complications resulting from radical resection in colorectal cancer (CRC). Accumulating evidence suggests that intestinal microbiota is correlated with anastomotic healing.

AIM

To explore the microbiota structural shift in margin-surrounding mucosa and evaluate the predictive ability of selected bacterial taxa for impaired anastomotic healing.

METHODS

Margin-surrounding mucosa samples derived from 37 patients were collected to characterize the microbial community structure by 16s rRNA gene sequencing. The patients were divided into two groups according to the healing status of anastomoses: well-healing group (n = 30) and impaired-healing group (n = 7). Statistic differences in bacteria taxa were compared by Wilcoxon test and chi-squared test. The predictive ability of the selected bacterial taxa for the healing status of anastomoses was evaluated by the area under the receiver operator characteristic curve.

RESULTS

Community structure shifts were observed in the impaired-healing group and well-healing group. Six bacterial species were found to be significantly correlated with anastomotic healing, and among these species, Alistipes shahii, Dialister pneumosintes, and Corynebacterium suicordis were considered as the predictive factors. Taking the known risk factor age into consideration, Alistipes shahii, Dialister pneumosintes, and Corynebacterium suicordis improved predictive ability for the healing status of anastomoses.

CONCLUSION

These data show that Alistipes shahii, Dialister pneumosintes, and Corynebacterium suicordis could be considered as supplementary factors in the prediction of anastomosis healing status in patients after CRC radical resection.