Incidence of and Risk Factors for Incisional Hernia After Hepatectomy for Colorectal Liver Metastases.

Background: Incisional hernia (IH) is common after major abdominal surgery; however, the incidence after hepatectomy for cancer has not been described. We analyzed incidence of and risk factors for IH after hepatectomy for colorectal liver metastases (CLM).

Methods: Patients who underwent open hepatectomy with midline or reverse-L incision for CLM at a single institution between 2010 and 2018 were retrospectively analyzed. Postoperative CT scans were reviewed to identify IH and the time from hepatectomy to hernia. Cumulative IH incidence was calculated using competing risk analysis. Risk factors were assessed using Cox proportional hazards model analysis. The relationship between IH incidence and preoperative body mass index (BMI) was estimated using a generalized additive model.

Results: Among 470 patients (median follow-up: 16.9 months), IH rates at 12, 24, and 60 months were 41.5%, 51.0%, and 59.2%, respectively. Factors independently associated with IH were surgical site infection (HR: 1.54, 95% CI 1.16-2.06, P = 0.003) and BMI > 25 kg/m (HR: 1.94, 95% CI 1.45-2.61, P < 0.001). IH incidence was similar in patients undergoing midline and reverse-L incisions and patients who received and did not receive a bevacizumab-containing regimen. The 1-year IH rate increased with increasing number of risk factors (zero: 22.2%; one: 46.8%; two: 60.3%; P < 0.001). Estimated IH incidence was 10% for BMI of 15 kg/m and 80% for BMI of 40 kg/m.

Conclusion: IH is common after open hepatectomy for CLM, particularly in obese patients and patients with surgical site infection. Surgeons should consider risk-mitigation strategies, including alternative fascial closure techniques.