Preoperative weight loss for open abdominal wall reconstruction: study protocol for a randomized controlled trial.

Background: Obesity is widely recognized as a risk factor for poor outcomes following ventral hernia repair. This belief has led many surgeons to implement arbitrary body mass index (BMI) cutoffs, typically 35-40 kg/m², before offering elective hernia repair. These practices are based on low-quality evidence and create significant challenges for patients with symptomatic hernias who lack access to metabolic and bariatric surgery or obesity medications. We aim to compare medical weight loss followed by surgery versus upfront surgery in patients with severe obesity undergoing ventral hernia repair.

Methods: This is a registry-based, parallel, randomized controlled trial with 1:1 allocation. A total of 258 patients with a BMI 40-55 kg/m² who are planning to undergo open retromuscular ventral hernia repair are randomized to a six-month preoperative medical weight loss program followed by surgery or upfront surgery. The medical weight loss program is conducted by a nurse practitioner trained in obesity medicine. The primary hypothesis is that abdominal wall-specific quality of life, as measured by Hernia-Related Quality-of-Life Survey (HerQLes) summary scores at one year, for the upfront abdominal wall reconstruction intervention will be non-inferior compared to a preoperative medical weight loss program followed by surgery. Secondary outcomes include hernia recurrence rates at one-year, wound morbidity at 30 days and one year, and rates of emergency hernia repair, readmissions, complications, and reoperations between groups. Patient-reported outcomes include quality of life and pain scores at baseline, 30 days, and after completing the standard medical weight loss program. Weight-related outcomes include changes in weight from enrollment through one-year follow-up, rate of achievement of weight loss goals, and the association of weight loss and program completion on postoperative outcomes. Lastly, we will evaluate cost-effectiveness using quality-adjusted life years and incremental cost-effectiveness ratios.

Discussion: Preoperative weight loss offers potential benefits for patients with obesity undergoing hernia repair including decreased wound morbidity, reduced technical difficulty, and potentially lower recurrence rates. However, disadvantages include prolonged diminished quality of life, risk of emergent hernia repair during the weight loss period, limited access to effective weight loss interventions, and challenges with adherence to weight loss protocols and long-term weight maintenance. This randomized controlled trial will provide high-quality evidence on whether intensive preoperative medical weight loss improves outcomes compared to immediate surgical repair in patients with severe obesity, helping to establish evidence-based guidelines for this challenging patient population.

Trial registration: NCT05925959 (registered June 22, 2023).