Distinction of Risk Factors for Superficial vs Organ-Space Surgical Site Infections After Pancreatic Surgery

Abstract

Surgical site infection (SSI) rates are increasingly used as a quality metric. However, risk factors for SSI in pancreatic surgery remain undefined. To stratify superficial and organ-space SSIs after pancreatectomy and investigate their modifiable risk factors. This retrospective analysis included 201 patients undergoing pancreatic surgery at a university-based tertiary referral center from July 1, 2013, through June 30, 2015, and 10 371 patients from National Surgical Quality Improvement Program-Hepatopancreaticobiliary (NSQIP-HPB) Collaborative sites from January 1, 2014, through December 31, 2015. Superficial, deep-incisional, and organ-space SSIs, as defined by NSQIP. Among the 201 patients treated at the single center (108 men [53.7%] and 93 women [46.3%]; median age, 48.6 years [IQR, 41.4-57.3 years]), 58 had any SSI (28.9%); 28 (13.9%), superficial SSI; 8 (4%), deep-incisional SSI; and 24 (11.9%), organ-space SSI. Independent risk factors for superficial SSI were preoperative biliary stenting (odds ratio [OR], 4.81; 95% CI, 1.25-18.56; P = .02) and use of immunosuppressive corticosteroids (OR, 13.42; 95% CI, 1.64-109.72; P = .02), whereas soft gland texture was the only risk factor for organ-space SSI (OR, 4.45; 95% CI, 1.35-14.66; P = .01). Most patients with organ-space infections also had grades B/C fistulae (15 of 24 [62.5%] vs 4 of 143 [2.8%] in patients with no SSI; P < .001). Organ/space but not superficial SSI was associated with an increased rate of sepsis (7 of 24 [29.2%] vs 4 of 143 [2.8%]; P < .001) and prolonged length of hospital stay (12 vs 8 days; P = .04). Among patients in the NSQIP-HPB Collaborative, 2057 (19.8%) had any SSI; 719 (6.9%), superficial SSI; 207 (2%), deep-incisional SSI; and 1287 (12.4%), organ-space SSI. Preoperative biliary stenting was confirmed as an independent risk factor for superficial SSI (OR, 2.07; 95% CI, 1.58-2.71; P < .001). In this larger data set, soft gland texture was an independent risk factor for superficial SSI (OR, 1.45; 95% CI, 1.14-1.85; P = .002) but was more strongly and significantly associated with organ-space SSI (OR, 2.32; 95% CI, 1.88-2.85; P < .001). Preoperative biliary stenting and coriticosteroid use increase superficial SSI, even in patients receiving perioperative piperacillin-tazobactam. Additional measures, including extended broad-spectrum perioperative antibiotic treatment, should be considered in these patients. Organ/space SSIs appear to be related to pancreatic fistulae, which are not modifiable. Reporting these different subtypes as a single, overall rate may be misleading.