An algorithm for assessment and treatment of postherniorrhaphy pain

Inguinal pain after groin hernia repair is a challenging issue. About 50 % of postherniorrhaphy pain allegedly is neuropathic, treatment of which is cumbersome given the limited efficacy of current therapeutic modalities. Possibly a clear protocol assessing the type of pain and treating it accordingly could improve its treatment.

A prospective study was done to evaluate an algorithm in patients with chronic postherniorrhaphy groin pain, aiming to select those with neuropathic pain and to treat appropriately. Treatment consisted of ultrasound-guided nerve blocks as an initial treatment for neuropathic pain. If long-term pain reduction proved inadequate, peripheral nerve stimulation was offered.

After our diagnostic workup consisting of anamnesis, physical examination and imaging, 68 patients out of 105 were diagnosed as having non-neuropathic pain. These patients were referred to the most appropriate consultant, treated accordingly or sometimes pain appeared to be self-limiting. Thirty-seven (35 %) patients were diagnosed as having neuropathic pain with a median NRS of 7 (range 4-9) and were referred for further treatment to our pain clinic. The majority (21 of 28 patients) suffered ileo-inguinal nerve involvement. After ultrasound-guided nerve blocks, a permanent reduction in pain was achieved in 18 patients (62 %) with a median post-treatment NRS of 1 (range 0-3). In six patients to which an additional peripheral nerve stimulator (PNS) was offered, pain reduction to a level of mild complaints with a median NRS of 2 (range 1-8) was observed. In total, 24 of the 28 patients (83 %) diagnosed with neuropathic postherniorrhaphy pain achieved significant pain reduction after algorithm-based treatment.

In the present study, we implemented a diagnostic workup for patients with postherniorrhaphy inguinal pain to select those with neuropathic pain. Eighty-three percent of the patients with neuropathic groin pain obtained significant improvement of their pain scores after our protocolled treatment. The effect was achieved by nerve infiltrations and in some cases by an implanted PNS when the former was unsuccessful.