No difference in outcomes between large- and small-pore meshes in a prospective, randomized, multicenter trial investigating open retromuscular meshplasty for incisional hernia repair

Study design A randomized, controlled, prospective multicenter clinical trial with a parallel group design was initiated in eight surgical centers to compare a large-pore polypropylene mesh (Ultrapro ® ) to a small-pore polypropylene mesh (Premilene ® ) within a standardized retromuscular meshplasty for incisional hernia repair. Methods Between 2004 and 2006, patients with a fascial defect with a minimum diameter of 4 cm after vertical midline laparotomy were recruited for the trial. Patients underwent retromuscular meshplasty with either a large-pore or a small-pore mesh to identify the superiority of the large-pore mesh. Follow-up visits were scheduled at 5 and 21 days and 4, 12, and 24 months after surgery. A clinical examination, a modified short form 36 (SF-36 ® ), a daily activity questionnaire, and an ultrasound investigation of the abdominal wall were completed at every follow-up visit. The primary outcome criterion was foreign body sensation at the 12-month visit, and the secondary endpoint criteria were the occurrence of hematoma, seroma, and chronic pain within 24 months postoperatively. Results In 8 centers, 181 patients were included in the study. Neither foreign body sensation within the first year after surgery (27.5% Ultrapro ® , 32.2% Premilene ® ) nor the time until the first occurrence of foreign body sensation within the first year was significantly different between the groups. Regarding the secondary endpoints, no significant differences could be observed. At the 2-year follow-up, recurrences occurred in 5 Ultrapro ® patients (5.5%) and 4 Premilene ® patients (4.4%). Conclusion Despite considerable differences in theoretical and experimental works, we have not been able to identify differences in surgical or patient-reported outcomes between the use of large- and small-pore meshes for retromuscular incisional hernia repair. Trial registration Clinical Trials NCT04961346 (16.06.2021) retrospectively registered.