The primary objective of the study is to demonstrate that hernia recurrence (VH) repair with non absorbable mesh concomitant to Bariatric Surgery (BS) decreases the risk of VH, with or without surgical repair, during the first two years after BS when compared to VH suture repair without mesh.

As secondary objectives, the study aims to assess the impact of concomitant VH repair with non absorbable mesh versus suture repair in morbidly obese BS candidates on the following measures: - hernia recurrence at 1 year after randomization; - reoperation for hernia recurrence at 2 years after randomization; - strangulated hernia, surgical infection and mesh bulging at one year after randomization; - postoperative morbidity and mortality at 90 days after randomization; - benefit-risk ratio; - chronic pain at three months, six months, one year and two years after randomization; - quality of life during the two years after randomization; - incremental cost utility ratio; - short- and mid-term weight loss. To study if the efficacy of mesh versus suture VH repair differs according to the type and size of VH and to the surgical technique.

This is a prospective, multicentric, superiority, comparative randomized (1:1) single-blinded clinical trial with blinded assessment of the primary endpoint.

Hypothesis for the study: abdominal ventral hernia (VH) repair with mesh during bariatric surgery (BS) is more effective than suture repair in preventing VH recurrence. Secondarily, we expect that mesh repair would not increase the risk of surgical site infection.

Population of study participants:

Patients between 18 and 60 years, presenting with VH and scheduled for BS, excluding pregnant women and protected adults.

All consecutive eligible patients will be invited to participate by visceral surgeons during preoperative consultations for BS. Included patients will be randomly assigned (1/1 ratio) to either mesh VH repair (intervention group) or suture VH repair (control group) by visceral surgeons at hospital admission (hospitalization or outpatient surgery) for BS and VH repair.

Patients will be followed according to clinical guidelines for BS follow-up at M1, M3, M6, M9, M12, M18 and M24 after BS.

There will be 29 surgical centers in France (digestive surgeons), targetting 354 eligible patients.

Statistical analysis:

An intention-to-treat statistical analysis will be performed at the end of the follow-up, when primary endpoint of all randomized patients will be documented.

The analysis for the primary endpoint will consist in comparing proportions of hernia recurrence during the two years after surgery between the two arms, using a Chi2 test.

An interim analysis is planned after half of the subjects finished their follow-up, in order to confirm the efficacy of the intervention arm, or alternatively its lack of efficacy.

Inclusion Criteria:

• Patients between 18 and 60 years.
• Body Mass Index (BMI) ≥ 40 kg/m² or ≥ 35 kg/m² associated with at least one comorbidity that can improve after BS.
• Body Mass Index (BMI) < 50 kg/m².
• Primary or first recurrent incisional midline VH, umbilical or epigastric, width between 1 cm and 4 cm, on abdominopelvic CT-scan without contrast injection.
• Decision for primary sleeve gastrectomy or by-pass after multidisciplinary discussion.
• Request for BS approved by health insurance authorities.
• Written informed consent from patient.

Exclusion Criteria:

• Previous VH repair with mesh.
• Other types of abdominal hernia (lateral, subxiphoidal, infraumbilical, suprapubic, parastomal, non-midline port-site, and groin hernia).
• Decision of performing BS by laparotomy.
• Reoperation for BS (excepted previous adjustable gastric banding).
• Ongoing abdominal skin infection.
• Emergency surgery.
• ASA (American Society of Anesthesiologists) score>3.
• Ongoing pregnancy or breast-feeding.
• Patient not covered by social insurance.
• Patient under legal guardianship.
• Patient already included in a clinical trial on hernia recurrence.