Objective To investigate the application value of porcine small intestinal sub-mucosa (SIS) acellular matrix mesh in laparoscopic inguinal hernia repair (LIHR).

Methods The prospective multicenter randomized controlled single-blind non‑inferiority‑type study was conducted. The clinical data of 216 patients who underwent LIHR in 4 medical centers, including Beijing Chaoyang Hospital of Capital Medical University et al, from April 2021 to August 2022 were selected. Patients were divided into two groups using a central randomization system. Patients in the experimental group were implanted domestic SIS mesh, and patients in the control group were implanted imported mesh of similar material origin. The baseline characteristics of enrolled patients were evaluated using the full analysis set, and the effectiveness indicators were evaluated using the protocol set. Measurement data with normal distribution were represented as Mean±SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M(range), and comparison between groups was conducted using the Wilcoxon rank sum test. Count data were expressed as absolute numbers and/or percentages, and comparison between groups was conducted using the chi‑square test or Fisher exact probability. If the lower limit of 95% confidence interval (CI) of the difference in effective rates between the experimental group and the control group was greater than the non‑inferiority cut‑off value of ‒10%, the experimental group was considered non‑inferior to the control group.

Results (1) Situations of the enrolled patients. A total of 216 patients were selected for eligibility, with 46 patients dropping out due to violation of the trial protocol, and the remaining 170 patients were included in the full analysis set. Nine patients were dislodged due to loss to follow‑up, and 161 patients completed follow‑up. One case in the experimental group was excluded due to violating the inclusion and exclusion criteria, while the remaining 160 patients were included in the protocol set (80 cases in the experimental group and 80 cases in the control group). There was no significant difference in the gender, age, body mass index (BMI), surgical method, Gilbert type of hernia, volume of intraoperative blood loss, operation time of patients between the experimental group and the control group (P>0.05), confounding bias ensured comparability. (2) Study endpoints. ① Primary study endpoint. During the postoperative 6 month of follow‑up, none of patient in the experimental group or the control group had hernia recurrence, with the recurrence rate as 0. Results of non‑inferiority test showed that the difference of hernia recurrence between the two groups was 0 (95%CI as ‒4.58% to 4.58%), with the lower limit of ‒4.58% greater than the non⁃inferiority cut‑off value of ‒10%, which fulfilled the non-inferiority hypothesis. ② Secondary study endpoints. Cases with plasmapheresis during the follow-up were 18 in the experimental group and 29 in the control group, respectively, showing no significant difference between the two groups (χ²=3.65, P>0.05). There were 4 cases with postoperative pain and 1 case with postoperative malaise in the experimental group, and there were 8 cases with postoperative pain and 0 case with postoperative malaise in the control group, showing no signifi-cant difference in the above indicators between the two groups (P>0.05). None of patient in the experimental group or the control group had incision infection, enterocutaneous fistula, intestinal obstruction, intestinal canal injury, allergy and rejection, testicular inflammation and/or atrophy, or any other complication.

Conclusion Compared with imported mesh of similar material origin, domestic porcine SIS mesh is safe and effective in LIHR.