Retromuscular mesh placement and intraperitoneal onlay mesh (IPOM) are associated with higher risks of reoperation for recurrence and bowel obstruction following primary ventral hernia repair compared with onlay placement, according to recent Danish research.

Mesh reinforcement is widely regarded as the standard approach for primary ventral hernia repair, but the optimal anatomical plane for mesh placement remains controversial. Current guidelines generally favour retromuscular or preperitoneal positioning to reduce the risk of recurrence, despite limited comparative evidence.

To address this uncertainty, researchers conducted a nationwide, register-based cohort study in Denmark to compare recurrence and bowel obstruction outcomes across four anatomical mesh placement techniques: onlay, retromuscular, preperitoneal and IPOM. The study was published in JAMA Surgery.

The analysis included 17,832 adults who underwent elective primary umbilical or epigastric hernia repair with mesh between January 2014 and April 2025. Patients with hernia defects of more than 10cm, emergency repairs, component separation procedures, Physiomesh implantation or a history of bowel obstruction were excluded. The median follow-up was 4.9 years.

Among the included patients, 8,764 underwent onlay repair, 1,239 retromuscular repair, 4,292 preperitoneal repair, and 3,537 IPOM repair. The primary outcomes were reoperation for recurrence and bowel obstruction requiring hospital diagnosis or intervention.

Reoperation and recurrence outcomes across mesh placements

Reoperation rates for recurrence were 1.9% for onlay repair, 2.9% for retromuscular, 1.9% for preperitoneal and 2.7% for IPOM repair.

After adjustment for age, sex, comorbidities, hernia size and year of repair, retromuscular mesh placement was associated with a significantly increased risk of reoperation for recurrence compared with onlay placement (hazard ratio [HR] 1.63; 95% CI 1.12–2.38).

IPOM was also associated with an increased recurrence risk (HR 1.38; 95% CI 1.02–1.86), while no difference was observed between onlay and preperitoneal placement.

Bowel obstruction occurred in 0.5% of patients undergoing onlay repair, 1.0% undergoing retromuscular repair, 0.7% undergoing preperitoneal repair and 2.6% undergoing IPOM repair.

Compared with onlay placement, both retromuscular placement (HR 2.01; 95% CI 1.05–3.82) and IPOM (HR 3.47; 95% CI 2.27–5.28) were associated with significantly increased risks of bowel obstruction.

Challenging current hernia guideline preferences

The authors noted that the increased recurrence risk observed with retromuscular mesh placement contrasts with current guideline recommendations favouring retromuscular and preperitoneal positioning. They suggested that the high proportion of robot-assisted procedures may have contributed to the observed findings.

Several limitations were acknowledged. The observational design precludes causal inference, residual confounding may persist because body mass index data were incomplete, and information on prior abdominal surgery and surgeon operative volume was unavailable. Competing mortality risks may also have influenced outcome estimates in older patients.

Nevertheless, the authors highlighted the study’s large sample size, nationwide coverage and complete follow-up as important strengths.

They concluded that, when considering the risks of both recurrence and bowel obstruction, onlay and preperitoneal mesh placement might represent preferable options for primary ventral hernia repair. However, future research is needed to further clarify the influence of surgical approach and mesh positioning on long-term outcomes.

Reference
Á Lakjuni Guttesen E et al. Mesh placement and risk of recurrence and bowel obstruction after primary ventral hernia repair. JAMA Surgery 2026 May 27: doi:10.1001/jamasurg.2026.1626.