S116: Impact of incisional negative pressure wound therapy on surgical site infection after complex incisional hernia repair: a retrospective matched cohort study.

Introduction: Incisional negative pressure wound therapy (iNPWT) may reduce surgical site infections (SSI), which can have devastating consequences after incisional hernia repair. Few comparative studies investigate the effectiveness of this wound management strategy in this population. The objective of this study is to determine the effect of iNPWT on the incidence of SSI after complex incisional hernia repair.

Methods: All adult patients undergoing open incisional hernia repair at a single center from 2016 to 2019 were reviewed. A commercial iNPWT dressing was used at the discretion of the surgeon. Patients were grouped by type of dressing; iNPWT and standard sterile dressings (SSD). Coarsened exact matching was used to create balanced cohorts for comparison using age, sex, American Society of Anesthesiologists classification, wound classification, and surgical urgency. The primary outcome was the composite incidence of superficial and deep SSI within 30 days. Secondary outcomes included non-infectious surgical site occurrences (SSO), overall complications, length of stay (LOS), emergency department visits, and readmission at 30 days.

Results: 134 patients underwent complex hernia repair, with 114 patients included after matching (34 iNPWT, 51 SSD). Composite incidence of superficial and deep SSI was 19.3% (11.8% vs. 27.5%, p = 0.107), with significantly lower rates of deep SSI in patients receiving iNPWT (2.9% vs. 17.6%, p = 0.045). After accounting for residual differences between groups, iNPWT was associated with decreased incidence of composite SSI (RR 0.36, 95% CI [0.16, 0.87]). Median LOS was longer in patients with iNPWT (7 vs. 5 days, p = 0.001). There were no differences in SSO, overall complications, readmission, or emergency department visits.

Conclusion: In patients undergoing incisional hernia repair, the use of iNPWT was associated with a lower incidence of SSI at 30 days. Future studies should focus on cost effectiveness of iNPWT, its impact on long-term hernia recurrences, and the identification of patient selection criteria in this population.