Three-Year Results of a Single-Centre Single-Blinded Randomised Study Evaluating the Impact of Mesh Pore Size on Chronic Pain after Lichtenstein Hernioplasty.

BACKGROUND AND AIMS: The aim of the present study was to determine whether usage of mesh with larger pores, compared with mesh with smaller pores, would result in a decreased rate of chronic pain at 3-year follow-up. According to earlier published short-term results, differences in mesh pore size do not influence the rate of chronic pain.

MATERIAL AND METHODS: The patients were randomized into two study groups for which meshes with similar weight but different pore size were used: the UM group received Ultrapro mesh (pore size 3-4 mm) and the OM group received Optilene LP mesh (pore size 1 mm). Pain scores were measured on a visual analog scale. The feeling of a foreign body was a yes-or-no question.

RESULTS: A total of 65 patients in the UM group and 63 patients in the OM group were included in analysis. Of the patients, 33.9% in the UM group and 15.9% in the OM group reported having experienced pain during different activities at 3-year follow-up (P = 0.025). Comparison with the results of 6-month follow-up (46.3% in the UM group, 34.3% in the OM group) showed that the rate of chronic pain had decreased significantly in the OM group (P = 0.009) but not in the UM group (P = 0.113). The feeling of a foreign body in the inguinal region was experienced by 23.1% of the patients in the UM group and by 15.9% in the OM group (P = 0.375). There was one hernia recurrence in the OM group. Severe preoperative pain and younger age were identified as risk factors for development of chronic pain.

CONCLUSIONS: Mesh with larger pores, compared with mesh with smaller pores, has no advantages in reducing the rate of chronic pain. We speculate that the reason for the higher rate of chronic pain in the study group where the mesh with larger pores was used might have been the different composition of the meshes at implantation. Also, it is possible as development of chronic pain after inguinal hernia repair is multifactorial, we failed to find a plausible explanation for this difference. Low recurrence rates were achieved with both meshes used in our study.