Prevention of incisional hernia with retrorectus synthetic mesh versus biological mesh following loop ileostomy closure (Preloop trial)

Background: The rate of incisional hernia after closure of a temporary loop ileostomy is significant. Synthetic meshes are still commonly avoided in contaminated wounds. The Preloop trial was a multicentre RCT designed to evaluate the benefits of synthetic mesh in incisional hernia prevention, and its safety for use in a contaminated surgical site compared with biological mesh.

Methods: Study patients who underwent closure of a loop ileostomy after anterior resection for rectal cancer were assigned to receive either retrorectus synthetic or biological mesh to prevent incisional hernia. The primary outcomes were surgical-site infections within 30 days, and clinical or radiological incisional hernia incidence at 10 months. Secondary outcomes were reoperation rate, operating time, duration of hospital stay, other complications within 30 days of surgery, 5-year quality of life measured by RAND-36, and incisional hernia incidence within 5 years of follow-up.

Results: Between November 2018 and September 2021, 102 patients were randomised, of whom 97 received the intended allocation. At 10-month follow-up, 90 patients had undergone clinical evaluation and 88 radiological evaluation. One patient in each group (2 per cent) had a clinical diagnosis of incisional hernia (P = 0.950) and one further patient in each group had a CT-confirmed incisional hernia (P = 0.949). The number of other complications, reoperation rate, operating time, and duration of hospital stay did not differ between the study groups.

Conclusion: Synthetic mesh appeared comparable to biological mesh in efficacy and safety for incisional hernia prevention at the time of loop ileostomy closure.

Registration number: NCT03445936 (http://www.clinicaltrials.gov).