Here is the design of a clinical trial:

Official Title: Multicenter, Prospective, Longitudinal and Randomized Comparison of Both the Clinical and Economic Impact of Biosynthetic Absorbable Mesh to the Surgical Standard of Care in Contaminated Incisional Hernia Repair

Included conditions:
- Ventral Hernia Repair

Study Armgroups:
- {'label': 'biosynthetic mesh group', 'type': 'EXPERIMENTAL', 'description': 'Patient will undergo incisional hernia repair with biosynthetic mesh reinforcement. Based on the discretion of the surgeon, two types of biosynthetic mesh from different brand can be used: the Phasix mesh from BARD or the BioA mesh from GORE. These two biosynthetic meshes are resorbable, which means they are gradually absorbed by the body.', 'interventionNames': ['Procedure: Incisional hernia repair with reinforcement of biosynthetic mesh']}
- {'label': 'standard of repair group', 'type': 'OTHER', 'description': 'Patient will undergo incisional hernia repair according to the standard of repair, which is simple suture or mesh reinforcement (using synthetic or biological meshes).', 'interventionNames': ['Procedure: Incisional hernia repair with simple suture or synthetic mesh reinforcement.']}

Interventions:
- {'type': 'PROCEDURE', 'name': 'Incisional hernia repair with reinforcement of biosynthetic mesh', 'description': 'The biosynthetic mesh (Phasix or Bio-A meshes) will be placed as a sublay in the retromuscular position to reinforce midline fascial closure. All the surgical procedure (including placement and fixation of the mesh) will be performed according to a standardized protocol.', 'armGroupLabels': ['biosynthetic mesh group']}
- {'type': 'PROCEDURE', 'name': 'Incisional hernia repair with simple suture or synthetic mesh reinforcement.', 'description': 'Based on the discretion of the surgeon, the incisional hernia repair will be done by simple suture or by synthetic mesh reinforcement. All the surgical procedure (including placement and fixation of the mesh if applicable) will be performed according to a standardized protocol.', 'armGroupLabels': ['standard of repair group']}

Primary Outcomes:
- {'measure': 'Rate of incisional hernia recurrence', 'description': 'The rate of incisional hernia recurrence will be evaluated by radiologic imaging.', 'timeFrame': '3 years after surgery'}

Please estimate the sample size based on the assumption: 
Power of 80%, two-sided alpha risk of 5%, and an increase of 15% to account for possible patients lost to follow-up and premature withdrawal.
Sample size calculation
          According to studies, the proportion of recurrent hernias at 3 years after being masked in a contaminated environment (grade III of the VHWG) treated according to the recommended technique reaches 75%.26
          The COBRA study reported a clinical recurrence rate at 2 years of 17% with the use of slowly absorbable mesh in a contaminated environment.27 This study was not comparative, and the relatively low rate of recurrence was possibly underestimated by the clinical definition of recurrence. Indeed, asymptomatic recurrences were not diagnosed.
          It was considered that 75% of patients would present with recurrent IH at 3 years in the control group. An absolute difference of 30% between the experimental group and the control group was expected. Under these assumptions, the inclusion of 47 patients in each group, for a total of 94 patients, would reveal a statistically significant difference between the two groups with a power of 80%. Numbers were calculated using Fisherâs exact test and a two-sided alpha risk of 5%.28 To take into account possible patients lost to follow-up and premature withdrawal, the number of patients needed would be increased by 15% to reach a total of 108 patients included (54 patients per group).