H. Nasser1, T. Ivanics1, S. Leonard-Murali1, A. Stefanou2 1Henry Ford Hospital,Department Of Surgery,Detroit, MI, USA 2Henry Ford Hospital,Division Of Colon And Rectal Surgery, Department Of Surgery,Detroit, MI, USA
Introduction: Surgical site infection (SSI) is a common complication following colon surgery. The aim of this study was to evaluate risk factors for SSI and its subtypes using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database.
Methods: The NSQIP database was queried for patients undergoing laparoscopic colectomy between 2011 and 2017. Univariate analysis and multivariable logistic regression were used to evaluate demographic variables, comorbidities, and operative factors associated with any SSI, superficial SSI, and organ-space SSI. Morbidity and mortality associated with each SSI subtype was evaluated using univariate analysis.
Results: A total of 72,519 patients were identified with 4,906 cases (6.77%) of SSI: 2,276 cases (3.14%) of superficial SSI and 2,483 cases (3.42%) of organ-space SSI. Patients with SSI were more likely to be younger (60.9 ± 15.2 vs 58.9 ± 15.7 years; p<0.01), male (51.1% vs 47.6%; p<0.01), have higher body mass index (29.5 ± 7.0 vs 28.4 ± 6.4 kg/m2, p<0.01), and have higher American Society of Anesthesiologists class ≥ 3 (56.3% vs 48.8%; p<0.01). The strongest risk factors for superficial SSI were admission prior to procedure (AOR=1.31; 95% CI 1.17-1.47; p<0.01), smoking (AOR=1.29; 95% CI 1.16-1.44; p<0.01), and higher body mass index (AOR=1.24 for every 5 kg/m2 increase; 95% CI 1.20-1.27; p<0.01). On the other hand, the strongest risk factors for organ-space SSI were wound class (AOR=2.45 for class 4 compared to ≤2; 95% CI 2.16-2.78; p<0.01), chemotherapy within 90 days (AOR=1.57; 95% CI 1.33-1.84; p<0.01), and steroid use (AOR = 1.46; 95% CI 1.29-1.65; p<0.01). Receiving a preoperative oral antibiotic prep was the strongest protective factor for both superficial SSI (AOR=0.49; 95% CI 0.44-0.54; p<0.01) and organ-space SSI (AOR=0.76; 95% CI 0.69-0.84; p<0.01). However, a preoperative mechanical bowel prep was only protective for organ-space SSI (AOR=0.85; 95% CI 0.78-0.93; p<0.01). Albumin < 3.5 g/dL was only associated with an increased risk of organ-space SSI (AOR=1.15; 95% CI 1.02-1.29; p=0.02). Selected risk factors associated with SSI are shown in Table 1. Organ-space SSI was associated with an increased overall mortality (3.1% vs 0.8%; p<0.01). Both superficial and organ-space SSI were associated with increased postoperative complications, although the risk was higher for organ-space SSI.
Conclusion: Superficial SSI and organ-space SSI in patients undergoing laparoscopic colectomy have different risk factors. Modifiable risk factors may provide an opportunity to reduce SSI risk and its associated morbidity.
