Incidence, Burden on the Health Care System, and Factors Associated With Incisional Hernia After Trauma Laparotomy.

Importance: The evidence provided supports routine and systematic capture of long-term outcomes after trauma, lengthening the follow-up for patients at risk for incisional hernia (IH) after trauma laparotomy (TL), counseling on the risk of IH during the postdischarge period, and consideration of preventive strategies before future abdominal operations to lessen IH prevalence as well as the patient and health care burden.

Objective: To determine burden of and factors associated with IH formation following TL at a population-based level across health care settings.

Design, Setting, and Participants: This population-based cohort study included adult patients who were admitted with traumatic injuries and underwent laparotomy with follow-up of 2 or more years. The study used 18 statewide databases containing data collected from January 2006 through December 2016 and corresponding to 6 states in diverse regions of the US. Longitudinal outcomes were identified within the Statewide Inpatient, Ambulatory, and Emergency Department Databases. Patients admitted with International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes for traumatic injuries with 1 or more concurrent open abdominal operations were included. Data analysis was conducted from March 2020 through June 2020.

Main Outcomes and Measures: The primary outcome was IH after TL. Risk-adjusted Cox regression allowed identification of patient-level, operative, and postoperative factors associated with IH.

Results: Of 35 666 patients undergoing TL, 3127 (8.8%) developed IH (median [interquartile range] follow-up, 5.6 [3.4-8.6] years). Patients had a median age of 49 (interquartile range, 31-67) years, and most were male (21 014 [58.9%]), White (21 584 [60.5%]), and admitted for nonpenetrating trauma (28 909 [81.1%]). The 10-year IH rate and annual incidence were 11.1% (95% CI, 10.7%-11.5%) and 15.6 (95% CI, 15.1-16.2) cases per 1000 people, respectively. Within risk-adjusted analyses, reoperation (adjusted hazard ratio [aHR], 1.28 [95% CI, 1.2-1.37]) and subsequent abdominal surgeries (aHR, 1.71 [95% CI, 1.56-1.88]), as well as obesity (aHR, 1.88 [95% CI, 1.69-2.10]), intestinal procedures (aHR, 1.47 [95% CI, 1.36-1.59]), and public insurance (aHRs: Medicare, 1.38 [95% CI, 1.20-1.57]; Medicaid, 1.35 [95% CI, 1.21-1.51]) were among the variables most strongly associated with IH. Every additional reoperation at the index admission and subsequently resulted in a 28% (95% CI, 20%-37%) and 71% (95% CI, 56%-88%) increased risk for IH, respectively. Repair of IH represented an additional $36.1 million in aggregate costs (39.9%) relative to all index TL admissions.

Conclusions and Relevance: Incisional hernia after TL mirrors the epidemiology and patient profile characteristics seen in the elective setting. We identified patient-level, perioperative, and novel postoperative factors associated with IH, with obesity, intestinal procedures, and repeated disruption of the abdominal wall among the factors most strongly associated with this outcome. These data support preemptive strategies at the time of reoperation to lessen IH incidence. Longer follow-up may be considered after TL for patients at high risk for IH.