Chronic pain after TEP inguinal hernia repair, does MRI reveal a cause?

Abstract

Purpose: Persistent pain is a known side effect after TEP inguinal repair disabling 2-5% of patients. A standardized diagnostic work-up so far is not available. MRI is a diagnostic tool in the work-up of inguinal hernias. In the present study the yield of MRI in evaluating chronic pain after TEP hernia repair is addressed.

Methods: In our database patients receiving an MRI scan for groin pain lasting more than 3 months after TEP inguinal hernia repair were identified. A checklist with potential pathologic findings was filled out for each groin by two blinded observers. Findings in painful, pain-free and unoperated groins were compared and statistical analysis done based upon their relative incidences. Cohen's kappa coefficients were calculated to determine interobserver agreement.

Results: Imaging studies of 53 patients revealed information regarding 106 groins. Fifty-five groins were painful after the initial operation, 12 were pain-free postoperatively and 39 groins were not operated. None of the predefined disorders was observed statistically more often in the patients with painful groins. Only fibrosis appeared more prevalent in patients with chronic pain (P = 0.11). Interobserver agreement was excellent for identifying the mesh (κ = 0.88) and observing bulging or a hernia (κ = 0.74) and was substantial for detecting fibrosis (κ = 0.63). In 40% of the patients, MRI showed a correct mesh position and observed nothing else than minor fibrosis. A wait and see policy resolved complaints in the majority of the patients. In 15 % of the patients, MRI revealed treatable findings explanatory for persisting groin pain.

Conclusion: For patients with post-TEP hernia groin pain, MRI is useful to confirm a correct flat mesh position and to identify possible not operation-related causes of groin pain. It is of little help to identify a specific cause of groin repair-related pain.

Keywords: Chronic pain; Endoscopic; Inguinal hernia; MRI; TEP.