Surgical options after a failed neurectomy in anterior cutaneous nerve entrapment syndrome.

BACKGROUND: Injection treatment followed by an anterior neurectomy in patients insufficiently responding to an injection regimen is successful long term in three-quarters of patients with anterior cutaneous nerve entrapment syndrome (ACNES). The efficacy of secondary surgery, including re-exploration or a posterior neurectomy in patients reporting recurrent pain after initially successful surgery or following an immediately failed anterior neurectomy is unknown. METHODS: A database of ACNES patients receiving surgery between 2004 and 2012 in the SolviMáx institution was analysed. Adult patients with residual pain after an anterior neurectomy (failures) or with recurrent pain after initially successful surgery (recurrences) were selected. Following a re-exploration or a posterior neurectomy, pain was scored using a pain intensity numeric rating scale (PI-NRS 0-10) and a six-point verbal category rating scale (VRS). Success was defined as a ≥50 % PI-NRS reduction and/or ≥2 point VRS reduction. RESULTS: ACNES patients undergoing an anterior neurectomy (n = 181) were analysed during the 8-year study period. At follow-up, 51 patients reported unacceptable pain levels following an anterior neurectomy, whereas 20 developed recurrent abdominal wall pain. Of these 71 unsuccessful patients, 41 underwent secondary surgery, including a re-exploration (n = 10), or a posterior neurectomy (n = 31). After a 25-month median follow-up, secondary surgical treatment regimens proved successful in 66 % (27/41). Patients with recurrent pain did better (14/15) than patients who were immediate failures after the anterior neurectomy (13/26, p = 0.01). CONCLUSIONS: Secondary surgery including re-explorations and posterior neurectomies are successful in two-thirds of ACNES patients with persistent pain or recurrence of pain after an anterior neurectomy.

Randomized clinical trial of trigger point infiltration with lidocaine to diagnose anterior cutaneous nerve entrapment syndrome.

BACKGROUND: Anterior cutaneous nerve entrapment syndrome (ACNES) is hardly considered in the differential diagnosis of chronic abdominal pain. Some even doubt the existence of such a syndrome and attribute reported successful treatment results to a placebo effect. The objective was to clarify the role of local anaesthetic injection in diagnosing ACNES. The hypothesis was that pain attenuation following lidocaine injection would be greater than that after saline injection. METHODS: Patients aged over 18 years with suspected ACNES were randomized to receive an injection of 10 ml 1 per cent lidocaine or saline into the point of maximal abdominal wall pain just beneath the anterior fascia of the rectus abdominis muscle. Pain was recorded using a visual analogue scale (VAS; 1-100 mm) and a verbal rating scale (VRS; 0, no pain; 4, severe pain) during physical examination just before and 15-20 min after injection. A reduction of at least 50 per cent on the VAS and/or 2 points on the VRS was considered a successful response. RESULTS: Between August 2008 and December 2010, 48 patients were randomized equally (7 men and 41 women, median age 47 years). Four patients in the saline group reported a successful response compared with 13 in the lidocaine group (P = 0·007). CONCLUSION: Entrapped branches of intercostal nerves may contribute to the clinical picture in some patients with chronic abdominal pain. Pain reduction following local infiltration in these patients was based on an anaesthetic mechanism and not on a placebo or a mechanical (volume) effect. REGISTRATION NUMBER: NTR2016 (Nederlands Trial Register; http://www.trialregister.nl).

Management of anterior cutaneous nerve entrapment syndrome in a cohort of 139 patients.

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.