Modifying Risk in Ventral Hernia Patients

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