Short-term complications after onlay versus preperitoneal mesh repair of umbilical hernias: a prospective randomized double-blind trial.

Purpose: To compare the incidence of surgical site occurrences (SSOs) following onlay versus preperitoneal mesh placement in elective open umbilical hernia repairs.

Methods: This study presents a secondary analysis of a randomized double-blind trial conducted on female patients with primary umbilical hernias admitted to a general hospital, in a residency training program setting. Fifty-six subjects were randomly assigned to either onlay (n=30) or preperitoneal (n=26) mesh repair group. Data on baseline demographics, past medical history, perioperative details, postoperative pain (visual analogue scale (VAS)), wound-related complications, and recurrence were assessed using a standardized protocol.

Results: No statistically significant differences were observed between groups regarding patients' demographics, comorbidities, or defect size. Operative time averaged 67.5 (28-110) min for onlay and 50.5 (31-90) min for preperitoneal repairs, p=.03. The overall rate of SSOs was 21.4% (n=12), mainly in the onlay group (33% vs 7.7%; p=0.02, 95% CI 0.03-0.85) and mostly due to seromas. There were no between-group significant differences in postoperative VAS scores at all timepoints. After a maximum follow-up of 48 months, one recurrence was reported in the onlay group. By logistic regression, the onlay technique was the only independent risk factor for SSOs.

Conclusion: The presented data identified a decreased wound morbidity in preperitoneal umbilical hernia repairs, thus contributing to the limited body of evidence regarding mesh place selection in future guidelines. Further cases from this ongoing study and completion of follow-up are expected to also compare both techniques in terms of long-term outcomes.

Trial Registration Number: Brazilian Registry of Clinical Trials (ReBEC) UTN code: U1111-1205-0065 (date of registration: March 27, 2018).