Modifying Risk in Ventral Hernia Patients

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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Modifying Risk in Ventral Hernia Patients

Conditions
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Hernia, Ventral, Weight Loss

Intervention / Treatment
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* Behavioral: Prehabilitation
* Behavioral: Standard counseling


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Prehabilitation<br>physical conditioning and weight loss intervention done pre-operatively | Behavioral: Prehabilitation<br>* information included in arm description<br>|
| Other: Standard Counseling<br>initial clinic counseling | Behavioral: Standard counseling<br>* information included in arm description<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of patients who are hernia- and complication-free |  | 2 years after enrollment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Weight loss (number of participants with weight loss of at least 7%) | number of participants with weight loss of at least 7% | 6 months after enrollment | 
| Receipt of elective or emergency surgery | When the patient underwent elective or emergent surgery | 6 months after enrollment | 
| surgery-related complications (number of patients who developed infections or other complications related to the surgery) | number of patients who developed infections or other complications related to the surgery | 2 years after surgery | 
| hernia-related complications (number of patients who developed complications from their hernia) | number of patients who developed complications from their hernia | 2 years after surgery | 
| Functional Status (Quality of life questionnaire responses) | Quality of life questionnaire responses | 2 years after surgery | 
| implementation outcomes (difference in costs between the patients in the treatment group and those in the usual care group) | difference in costs between the patients in the treatment group and those in the usual care group | 2 years | 
| Physiologic changes (number of pounds lost/gained) | number of pounds lost/gained | 2 years after surgery | 
| Metabolic changes (difference in basal metabolic rate before treatment and after treatment) | difference in basal metabolic rate before treatment and after treatment | 2 years after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ventral Hernia, Prehabilitation