Microbiology of pancreatoduodenectomy and recommendations for antimicrobial prophylaxis

Patterns, Predictors, and Outcomes of Bacterial Growth and Infectious Complications after Pancreatic Resection

BACKGROUND AND OBJECTIVES

Infectious complications after pancreatic resections are common, but perioperative factors linked to postoperative bacterial growth are not well-studied.

METHODS

This retrospective study analyzed bacterial cultures from patients undergoing pancreatic resection (November 2008 to October 2022), assessing predictors for positive cultures and characterizing bacteria. Complications and outcomes of patients with positive cultures were also examined.

RESULTS

Among 620 patients, bile samples were collected in 95 (95/620; 15.3%), with 60 (60/95; 63.1%) testing positive, 58 of them underwent pancreaticoduodenectomy. Of these, in 50 (50/58; 86.2%) the culture yielded polymicrobial growth but specific types of bacteria were not identified. Multivariate analysis identified preoperative bile duct stenting as a significant predictor of positive bile cultures (OR: 3.54; 95% CI: 1.95-6.42; p < 0.001), and positive cultures were linked to higher reoperation rates (OR: 2.40; 95% CI:1.18-4.90; p < 0.001. Positive drain cultures within 30 days from surgery were associated with higher rates of clinically significant pancreatic fistula (OR: 2.24; 95% CI: 1.00-5.11; p = 0.05), and reoperations) OR: 4.37; 95% CI: 1.62-11.79; p = 0.03). Patients with pancreatic adenocarcinoma and positive bile cultures had shorter disease-free survival with a median of 13 months (95% CI: 8-17) versus 18 months (95% CI: 8-29; p = 0.04).

CONCLUSIONS

Bile sampling is recommended in all pancreaticoduodenectomies. Managing polymicrobial growth with broad and prolonged antibiotics may reduce postoperative infections.

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.

Antibiotic Prophylaxis with Piperacillin-Tazobactam Reduces Post-Operative Infectious Complication after Pancreatic Surgery: An Interventional, Non-Randomized Study

Background: This study aimed to evaluate the effectiveness of piperacillin-tazobactam as antibiotic prophylaxis in patients affected by a peri-ampullary tumor submitted to pancreatic surgery. Methods: A prospective, non-randomized, non-blinded, interventional study was conducted from January 2015 to March 2018. Patients were screened pre-operatively for Enterobacteriaceae producing extended-spectrum beta-lactamases (ESBL-PE). During the baseline period (January 2015-October 2016), surgical prophylaxis was performed with ampicillin-sulbactam. In the intervention phase (November 2016-March 2018), patients received piperacillin-tazobactam. Statistical analysis was performed by univariable and multivariable analysis with logistic regression models. Results: Overall, 383 patients were included in the baseline period and 296 in the intervention period. The surveillance strategy identified 47 ESBL-PE carriers (14%) in the baseline phase and 29 (10%) in the intervention phase. In the baseline period, the patients had a higher rate of hospital-acquired infection (43% versus 33%; p = 0.004), superficial surgical site infection (SSI) (11% versus 2%; p < 0.001), and pneumonia (16% versus 9%; p = 0.006). After the logistic regression, the baseline group had an odds ratio to develop superficial SSI and pneumonia of 7.7 (95% confidence interval [CI] 3-20) and 1.8 (95% CI 1-3.3), respectively. The ESBL colonization increased the mortality rate significantly (8% versus 3%; p = 0.017). Conclusions: Adopting antibiotic prophylaxis based on piperacillin-tazobactam is associated with a reduction in post-operative SSI, particularly superficial-SSIs. Further randomized studies would be warranted to evaluate this antibiotic combination more extensively in preventive strategies.

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.

Oncobiosis and Microbial Metabolite Signaling in Pancreatic Adenocarcinoma

Pancreatic adenocarcinoma is one of the most lethal cancers in both men and women, with a median five-year survival of around 5%. Therefore, pancreatic adenocarcinoma represents an unmet medical need. Neoplastic diseases, such as pancreatic adenocarcinoma, often are associated with microbiome dysbiosis, termed oncobiosis. In pancreatic adenocarcinoma, the oral, duodenal, ductal, and fecal microbiome become dysbiotic. Furthermore, the pancreas frequently becomes colonized (by Helicobacter pylori and Malassezia, among others). The oncobiomes from long- and short-term survivors of pancreatic adenocarcinoma are different and transplantation of the microbiome from long-term survivors into animal models of pancreatic adenocarcinoma prolongs survival. The oncobiome in pancreatic adenocarcinoma modulates the inflammatory processes that drive carcinogenesis. In this review, we point out that bacterial metabolites (short chain fatty acids, secondary bile acids, polyamines, indole-derivatives, etc.) also have a role in the microbiome-driven pathogenesis of pancreatic adenocarcinoma. Finally, we show that bacterial metabolism and the bacterial metabolome is largely dysregulated in pancreatic adenocarcinoma. The pathogenic role of additional metabolites and metabolic pathways will be identified in the near future, widening the scope of this therapeutically and diagnostically exploitable pathogenic pathway in pancreatic adenocarcinoma.