Polypropylene vs. stainless-steel wire suture: short-term recurrence rate after shouldice primary inguinal hernia repair, a non-inferior analysis among 1120 patients. A case-control study

Introduction: Polypropylene material is commonly used for posterior wall reconstruction in hernia repair, in contrast with the classically described stainless-steel wire used at Shouldice Hospital. This study was conducted to evaluate possible differences in Shouldice Repair outcomes using polypropylene or stainless-steel wire sutures.

Methods: A prospective follow-up of consecutive patients who underwent elective unilateral Shouldice primary inguinal hernia repair at Shouldice Hospital between December 6, 2021, and September 1, 2022, was conducted. Data was collected from follow-up telephone calls as well as manually reviewing patient's charts. The primary objective was to determine whether the use of polypropylene was non-inferior to the use of stainless-steel wire, regarding the recurrence rate reported by the patients with a minimum follow-up of 1 year after Shouldice primary inguinal hernia repair.

Results: A total of 1120 patients were contacted by telephone (polypropylene: 560; stainless-steel wire: 560). The median follow-up period was 16 months (interquartile range: 15-18). In 22 (1.96%) cases a surgical site infection was diagnosed. There was a total of 18 recurrences reported by the patients (1.6%). There was no statistical difference between the groups (polypropylene: 7 (1.25%) vs. stainless steel wire: 11 (1.96%), p > 0.05) for the recurrence rate.

Conclusion: The use of polypropylene is non-inferior to the use of stainless-steel wire regarding recurrence rate at a median follow-up period of 16 months after elective unilateral Shouldice primary inguinal hernia repair. This finding may encourage other centers where stainless-steel wire is not easily available to perform the Shouldice Repair.