Evaluation of Chronic Pain after Inguinal Hernia Repair: Risk Factors and Prevention—A Prospective Single-Center Study

Chronic post-herniorrhaphy inguinal pain (CPIP) remains one of the most under-addressed and clinically significant complications in modern hernia surgery. Defined as persistent pain beyond 3 months postoperatively, CPIP affects approximately 10–20% of patients, with 2–5% reporting severe, disabling pain that impairs daily function, work capacity, and psychological well-being. Despite inguinal hernia repair being among the most frequently performed operations globally—with over 20 million procedures annually—CPIP continues to represent a major source of patient dissatisfaction, medicolegal claims, and healthcare burden. The etiology is predominantly neuropathic, arising from iatrogenic injury to the ilioinguinal, iliohypogastric, or genitofemoral nerves during dissection, mesh placement, or fixation. However, risk stratification and preventive strategies remain inconsistently applied across surgical practice. This study aimed to prospectively identify modifiable and non-modifiable risk factors for CPIP in a large, consecutive cohort of patients undergoing primary unilateral inguinal hernia repair at a tertiary academic center. Furthermore, we evaluated the real-world clinical impact of implementing a standardized, evidence-based preventive protocol—including intraoperative nerve identification and preservation, lightweight mesh selection, fibrin glue fixation, and preoperative transversus abdominis plane (TAP) blocks—on the incidence and severity of chronic pain. Between January 2020 and December 2023, 1,200 consecutive adult patients undergoing elective primary unilateral inguinal hernia repair (Lichtenstein open or totally extraperitoneal [TEP] laparoscopic approach) were enrolled in this prospective observational study with interventional implementation. Exclusion criteria included emergency repairs, bilateral procedures, known neuropathies, psychiatric comorbidities, or loss to follow-up before 3 months. Preoperative, intraoperative, and postoperative variables were meticulously recorded. Pain was assessed using the Visual Analog Scale (VAS) and the DN4 neuropathic pain questionnaire at 1, 3, 6, and 12 months postoperatively. Quality of life was evaluated using the SF-36 Health Survey at 12 months. Multivariate logistic regression analysis was performed to identify independent predictors of CPIP. From June 2021, a standardized “Prevention Protocol” was implemented and outcomes compared with the pre-protocol cohort. Chronic pain (>3 months, VAS ≥3) occurred in 148 patients (12.3%), with 37 (3.1%) reporting severe pain (VAS ≥5 at 6 months). Neuropathic characteristics (DN4 ≥4) were present in 68.2% of chronic pain cases. Multivariate analysis identified five independent predictors: age <50 years (OR = 3.21, 95% CI 2.01–5.13, p<0.001), preoperative pain (OR = 4.87, 95% CI 3.12–7.60, p<0.001), recurrent hernia (OR = 3.95, 95% CI 2.20–7.09, p<0.001), intraoperative nerve injury (OR = 5.33, 95% CI 2.98–9.54, p<0.001), and suture fixation (OR = 2.78, 95% CI 1.76–4.39, p<0.001). Implementation of the combined prevention protocol (nerve preservation + lightweight mesh + glue fixation + TAP block) reduced CPIP incidence from 15.2% to 4.3% (p<0.001), representing a 71.7% relative risk reduction. Patients with CPIP demonstrated significantly impaired SF-36 scores across all domains, particularly bodily pain (42.1 vs. 91.3, p<0.001) and social functioning (58.7 vs. 87.5, p<0.001). Chronic pain after inguinal hernia repair is not an unavoidable consequence of surgery but a preventable complication rooted in identifiable and modifiable technical and patient-related factors. A systematic, nerve-centric surgical approach—supported by lightweight prosthetics, non-traumatic fixation, and regional anesthesia—can reduce the incidence of CPIP by over 70%. We advocate for the adoption of our prevention algorithm as a new standard of care in hernia surgery and recommend routine auditing of chronic pain rates as a core quality indicator.