Discordance Between Perioperative Antibiotic Prophylaxis and Wound Infection Cultures in Patients Undergoing Pancreaticoduodenectomy

IMPORTANCE: Wound infections after pancreaticoduodenectomy (PD) are common. The standard antibiotic prophylaxis given to prevent the infections is often a cephalosporin. However, this decision is rarely guided by microbiology data pertinent to PD, particularly in patients with biliary stents. OBJECTIVE: To analyze the microbiology of post-PD wound infection cultures and the effectiveness of institution-based perioperative antibiotic protocols. DESIGN, SETTING, AND PARTICIPANTS: The pancreatic resection databases of 3 institutions (designated as institutions A, B, or C) were queried on patients undergoing PD from June 1, 2008, to June 1, 2013, and a total of 1623 patients were identified. Perioperative variables as well as microbiology data for intraoperative bile and postoperative wound cultures were analyzed from June 1, 2008, to June 1, 2013. INTERVENTIONS: Perioperative antibiotic administration. MAIN OUTCOMES AND MEASURES: Wound infection microbiology analysis and resistance patterns. RESULTS: Of the 1623 patients who underwent PD, 133 with wound infections (8.2%) were identified. The wound infection rate did not differ significantly across the 3 institutions. The predominant perioperative antibiotics used at institutions A, B, and C were cefoxitin sodium, cefazolin sodium with metronidazole, and ampicillin sodium-sulbactam sodium, respectively. Of the 133 wound infections, 89 (67.1%) were deep-tissue infection, occurring at a median of 8 (range, 1-57) days after PD. A total of 53 (40.0%) of the wound infections required home visiting nurse services on discharge, and 73 (29.1%) of all PD readmissions were attributed to wound infection. Preoperative biliary stenting was the strongest predictor of postoperative wound infection (odds ratio, 2.5; 95%CI, 1.58-3.88; P = .03). There was marked institutional variation in the type of microorganisms cultured from both the intraoperative bile and wound infection cultures (Streptococcus pneumoniae, 114 cultures [47.9%] in institution A vs 3 [4.5%] in institution B; P = .001) and wound infection cultures (predominant microorganism in institution A: Enterococcus faecalis, 18 cultures [51.4%]; institution B: Staphylococcus aureus, 8 [43.9%]; and institution C: Escherichia coli, 17 [36.2%], P = .001). Similarly, antibiotic resistance patterns varied (resistance pattern in institution A: cefoxitin, 29 cultures [53.1%]; institution B: ampicillin-sulbactam, 9 [69.2%]; and institution C: penicillin, 32 [72.7%], P < .001). Microorganisms isolated in intraoperative bile cultures were similar to those identified in wound cultures in patients with post-PD wound infections. CONCLUSIONS AND RELEVANCE: The findings of this large-scale, multi-institutional study indicate that intraoperative bile cultures should be routinely obtained in patients who underwent preoperative endoscopic retrograde cholangiopancreatography since the isolated microorganisms closely correlate with those identified on postoperative wound cultures. Institution-specific internal reviews should amend current protocols for antibiotic prophylaxis to reduce the incidence of wound infections following PD