Comparison of Open and Endoscopic Transversus Abdominis Release for Midline Incisional Ventral Hernia - a Randomized Controlled Trial

Minimally invasive (endoscopic) transversus abdominis release (TAR) - new technique for the treatment of patients with large incisional ventral hernia. Term "endoscopic" TAR combines two minimally invasive (laparosopic or extraperitoneal (eTEP) approaches. These techniques have demonstrated significant advantages compared with open TAR in several retrospective studies. There are currently no randomized trials comparing open and endoscopic TAR operations for incisional ventral hernia repair.This study aims to comparatively evaluate the early and long-term results of open and endoscopic TAR procedure for large midline incisional ventral hernias.

The sample size was determined based on a previously conducted retrospective pilot study comparing the results of open and endoscopic TAR procedures for midline incisional ventral hernia repair. The retrospective study included 133 patients with midline incisional ventral hernias who were underwent Rives-Stoppa hernia repair in combination with bilateral posterior component separation with transversus abdominis release via open (open TAR) or endoscopic (eTAR) technique in Moscow City Hospital №1 from January 2018 to December 2022. All patients were included in the study, starting from the moment of endoscopic TAR technique was introduced into the clinic. At the same time, the learning curve for the open TAR had already been reached at that time; more than 20 open TAR interventions were performed in the clinic in 2016-2017. The average hospitalization time in open TAR group was 6.7 ± 2.14 days. In endoscopic TAR group the average hospitalization time after surgery was 5.2 ± 1.65 bed days. After achieving the learning curve (20 operations) for the endoscopic TAR procedure technique average hospitalization period after surgery was 4.8 ± 1.47 days. Thus, a decrease in the duration of hospitalization in endoscopic TAR group after reaching the learning curve was noted by 28.4%. This fact, based on a retrospective pilot study, allows the investigators to assume as a hypothesis for this RCT a reduction in the duration of hospitalization during endoscopic TAR by at least 30% as a guideline for calculating the power of the study. Thus, assuming a Type I error probability α of 0.05 and a Type 2 error probability β of 0.20, it would require a total sample size of 36 patients (18 patients in each group).