Analysis of retromuscular drain output and postoperative outcomes for heavyweight versus mediumweight polypropylene mesh following open ventral hernia repair

Purpose Heavyweight polypropylene (HWPP) mesh is thought to increase inflammatory response and delay tissue integration compared to mediumweight (MWPP). Reactive fluid volume (i.e., drain output) may be a reasonable surrogate for integration. We hypothesized that daily drain output is higher with HWPP compared to MWPP in open retromuscular ventral hernia repair (VHR). Methods This is a post-hoc analysis of a multicenter, randomized clinical trial conducted March 2017-April 2019 comparing MWPP and HWPP for VHR. Retromuscular drain output in milliliters was measured at 24-h intervals up to postoperative day seven. Univariate analyses compared differences in daily drain output and time to drain removal. Multivariable analyses compared total drain output and wound morbidity within 30 days and hernia recurrence at 1 year. Results 288 patients were included; 140 (48.6%) HWPP and 148 (51.4%) MWPP. Daily drain output for days 1-3 was higher for HWPP vs. MWPP (total volume: 837.8 mL vs. 656.5 mL) (p < 0.001), but similar on days 4-7 (p > 0.05). Median drain removal time was 5 days for both groups. Total drain output was not predictive of 30-day wound morbidity (p > 0.05) or hernia recurrence at 1 year (OR 1, p = 0.29). Conclusion While HWPP mesh initially had higher drain outputs, it rapidly returned to levels similar to MWPP by postoperative day three and there was no difference in clinical outcomes. We believe that drains placed around HWPP mesh can be managed similarly to MWPP mesh.