Objective: Anterior cutaneous nerve entrapment syndrome (ACNES) is generally neglected as a source of chronic abdominal pain. The aim of this study was to evaluate the efficacy of a diagnostic workup protocol and treatment regimen in patients with suspected ACNES.
Methods: A cohort of all consecutive patients presenting with chronic abdominal pain suggestive of ACNES between 2003 and 2008 was evaluated retrospectively. Patients were offered a single diagnostic injection of 1% lidocaine into the trigger point followed by subsequent therapeutic injections including corticosteroids. If pain was refractory, an anterior neurectomy was performed. Pain scores were done using a visual analog scale for evaluation of the injection regimen and Verbal Rating Scale (1-5) for long-term efficacy.
Results: A total of 139 patients with suspected ACNES (77% women, mean age 47 ± 17 years) were evaluated. Eighty-one percent (n = 94) demonstrated a visual analog scale reduction of at least 50% after the first injection. Some 33% (n = 44) remained permanently pain-free after injection therapy only. Sixty-nine patients underwent a neurectomy, which was successful in 49 (71%). Long-term efficacy revealed in 71% (very) satisfying visual rating scale (1-2) results, whereas an additional 9% reported attenuated levels of pain (visual rating scale 3).
Conclusion: A regimen of consecutive local trigger point injections is effective in one-thirds of patients with ACNES. Surgical neurectomy is effective in about two-thirds of the injection regimen refractory patients. Eighty percent of the entire ACNES population reports total or substantial pain relief on the long term.