Retromuscular, periprosthetic drainage after hernioplasty with sublay mesh reinforcement in ventral hernias results in less retromuscular fluid collections but longer hospital stay and analgetic use with unclear effect on clinical outcome - a randomized controlled trial.

Purpose: To determine whether periprosthetic drain insertion for hernioplasty using sublay mesh augmentation influences retromuscular fluid collections (RFC) and the clinical course.

Methods: Forty-two patients with open repair of midline hernias (M2-4, W1, European Hernia Society classification) were allocated to groups with or without retromuscular drains. Subcutaneous drainages were used in both groups to avoid confounding from surgical site occurrences due to superficial, subcutaneous fluid collections. The participants underwent clinical and ultrasound assessments on postoperative days (POD) 14 and 30 to detect RFC, subcutaneous seromas, and wound complications. The sample size was estimated using the RFC of a test cohort with drainage; the assumed relevant volume (5 ml) was calculated comprising 84% (mean + 1 SD) of these patients.

Results: In the retromuscular drainage group, the RFC median volume was reduced by 75.2% on POD 14, and by POD 30, no RFC were found [0.2 vs. 25.8 (p < 0.001) and 0 vs. 4.0 (p = 0.02) on PODs 14 and 30, respectively]. The number of patients with RFC ≥ 5 mL was also significantly lower in the drainage group [4 vs. 12 (p = 0.02) and 1 vs. 8 (p = 0.02) on PODs 14 and 30, respectively]. No surgical site infections occurred in either group, but retromuscular hematoseroma led to one revision surgery and one needle aspiration in the group without drainage. In the drainage group, a significantly longer hospital stay (6.5 days vs. 4 days; p = 0.01) and longer regular analgetic intake (6 vs. 3 days; p = 0.03) were observed. Multivariable regression revealed that retromuscular drainage usage was the only independent predictor of the RFC volume.

Conclusion: We found that the use of retromuscular drains after hernioplasty with sublay hernia repair reduced periprosthetic fluid collections in our population but prolonged hospital stay. Whether the reduction of RFC can prevent SSO or revision surgery cannot be determined from our data, the relevance is therefore not assessable. Hence, further larger studies are required to determine the clinical relevance of drains.