A pre-operative physical conditioning and weight loss intervention (prehabilitation) compared to standard counseling prior to ventral hernia repair for obese patients (BMI 30-40 kg/m2) at a safety-net hospital results in a higher proportion of patients being hernia- and complication-free 2 years after surgical consultation.

Background:

Obesity is a risk factor for ventral hernia complications with or without repair, but the management strategy that best balances overall risks and benefits for obese patients with ventral hernias is unknown. The primary aim of this project is to compare the effect of prehabilitation (preoperative physical conditioning and weight loss intervention) versus standard preoperative counseling followed by repair for obese patients (BMI 30-40 kg/m2) with ventral hernias on outcomes.

Methods:

A comprehensive cohort study of obese patients who have ventral hernias will be performed. Within the comprehensive cohort study, patients who are candidates for elective ventral hernia repair will be randomized to a prehabilitation intervention or standard counseling with surgical repair once weight loss goals have been met. All patients will have repair after 6 months even if they have not met their weight loss goals. Patients who are not eligible for the trial or who refuse to participate will be followed in a non-randomized cohort; they will have their hernia repaired based upon current institution standards. (figure 1) The primary outcome of the study will be proportion of patients who are hernia- and complication- free 2 years after surgical consultation. This composite outcome was chosen in order to encompass all clinically important risks and benefits of both operative and non-operative strategies. Based on power calculations(alpha=0.05, beta=0.20), 232 eligible patients are needed assuming a 30% non-enrollment and 50% dropout. Since this is an efficacy trial, analysis will be performed per protocol as well as intention to treat. The primary outcome will be compared using the Cochran-Mantel-Haenszel test. Generalized linear mixed models (GLMMs) will be used to identify independent predictors of a successful outcome defined as hernia- and complication free at 2 years. In addition to a frequentist analysis, a Bayesian analysis will be performed. Posterior point estimates, credible intervals, and probability of increase in proportion of patients without hernias or complications will be calculated.

Conclusion:

Prehabilitation may have no impact on outcomes following ventral hernia repair, cause more complications with acute hernia presentation, or prove superior and decrease recurrences and complications compared to standard of care. This randomized controlled trial will provide baseline information on the efficacy of prehabiliation prior to open ventral hernia repair in obese patients.

Inclusion Criteria:

• Patient desires an elective surgical repair
• Diagnosis of a ventral hernia with width on CT scan of 3-20 cm in diameter
• Age 18 years or greater
• Able to give informed consent
• BMI of 30-40 kg/m2
• Surgical candidate based upon surgeon assessment

Exclusion Criteria:

• Patient has a severe comorbid condition likely to limit survival to < 2 years
• Patient has cirrhosis with or without ascites
• Patient has a bowel obstruction, strangulation, peritonitis, or perforation
• Patient has an indication for urgent surgery determined by surgeon such as full-thickness skin breakdown, enterocutaneous fistula, intermittent incarceration, or severe symptoms
• Patient has a local or systemic infection
• Patient is a prisoner
• Patient is pregnant or intends to become pregnant during the study period