To investigate the clinical efficacy of a composite basement membrane biological mesh compared to the small intestine submucosa (SIS) mesh for open tension-free inguinal hernia repair.

From January 2019 to January 2020, a randomized, single-blind, parallel-controlled, multicenter trial was conducted at five centers: Huadong Hospital Affiliated to Fudan University, Second Affiliated Hospital of Naval Medical University (Shanghai Changzheng Hospital), Zhongshan Hospital Affiliated to Fudan University, First People's Hospital of Hangzhou City, and First Affiliated Hospital of Wenzhou Medical University. Patients with unilateral primary inguinal hernia who voluntarily underwent open tension-free hernia repair were recruited. Patients with inguinal hernia who met the inclusion criteria but did not meet the exclusion criteria were randomly divided into experimental group and control group according to the ratio of 1:1. The experimental group received composite basement membran biological mesh while the control group received the SIS mesh. Both groups underwent tension-free inguinal hernia repair following Lichtenstein's technique. The recurrence rate and complication rate were observed in the patients 180 days after surgery, and long-term follow-up was completed for 4 years postoperatively.

During the one-year study period, a total of 140 patients were recruited from the five centers, and 2 patients in the experimental group dropped out during the study period. Finally, 138 patients were included in the study, with 68 cases in the experimental group and 70 cases in the control group. The experimental group had lower body weight and body mass index compared to the control group, showing statistical significance (P=0.028, 0.035). There were no statistically significant differences in terms of other baseline characteristics between the two groups. The operative time in the experimental group was shorter than that in the control group (P=0.035). In terms of movement Visual Analog Scale (VAS) scores, the experimental group had lower scores than the control group, with significant intergroup differences (F=6.165, P=0.014), which remained consistently lower than those of the control group at different time points with significant differences (F=168.4, P<0.0001). There was also a significant interaction between time and movement VAS scores between both groups (F=2.921, P=0.034).The incidence of seroma in the experimental group (4.62%) was significantly lower than that in the control group (15.39%), with a statistically significant difference (P=0.047). No recurrence occurred in the experimental group and one recurrence in the control group 180 days after surgery, with no significant difference in hernia recurrence rate between the two groups (P>0.05). The results of non-inferiority test showed that the 95% confidence interval of the difference in the hernia recurrence rate between the two groups was -6.23%~3.45%, with the upper limit of confidence interval <10%. In the follow-up 4-year period, 58 patients in the experimental group had no hernia recurrence, while 4 of the 54 patients in the control group experienced recurrence, with 2 of them undergoing reoperation, with no statistical difference in the recurrence rate between the two groups (P=0.109).

The composite basement membrane biological mesh is non-inferior to the SIS mesh in open tension-free inguinal hernia repair, especially in terms of incidence of seroma. The new composite basement membrane mesh is better than the SIS mesh.