Onlay versus sublay mesh repair of open ventral incisional hernia: A meta-analysis of randomized controlled trials
Background: Incisional hernia treatment remains a major issue in abdominal wall surgery. Open onlay and sublay mesh repair are the most frequently used procedures. This meta-analysis aimed to compare the two techniques for open ventral incisional hernia repair in terms of wound infection, hematoma, seroma, and recurrence.
Methods: A search in electronic databases for randomized controlled trials (RCTs) published up to September 30, 2019 was performed. Review Manager Version 5.3 was used for pooled estimates. The eligibility criteria were as follows: RCTs comparing onlay mesh repairs performed according to Cheverel with sublay mesh repairs performed according to Rives-Stoppa and Schumpelick and including patients aged 18 or older.
Results: Of 22 relevant articles, 7 RCTs involving a total of 954 patients (487 onlay and 466 sublay mesh repairs) met the eligibility criteria. Sublay mesh repairs were found to require better results in terms of wound infection (odds ratio [OR]: 2.33, 95% CI: 1.09–4.94, p = 0.03) and seroma (OR: 3.71, 95% CI: 2.26–6.09, p <0.001). There was no significant difference between the two techniques in terms of hematoma (OR: 2.53, 95% CI: 0.90–7.11, p = 0.08). Regarding recurrence, the forest plot showed no statistical difference (OR: 1.75, 95% CI: 0.55–5.55, I2 = 54%, p = 0.34); however, heterogeneity was high (I2 = 54%), and meta-regression showed a statistically significant difference in favor of sublay mesh repair.
Conclusions: This meta-analysis of RCTs shows that sublay mesh repair of open ventral incisional hernias is superior to onlay repair. Sublay mesh repair should probably be the first choice, and onlay repair should be reserved for more difficult cases, where sublay repair is not possible.
Keywords: Incisional hernia; onlay; sublay; recurrence; surgical site infection; wound complications; meta-regression