Free muscle flap coverage as last resort for therapy-resistant neuropathic pain in the upper extremity: A long-term retrospective follow-up study

Abstract

Persistent neuropathic pain severely impacts physical functioning and quality of life (QoL). However, optimal surgical management of persistent neuropathic pain remains unclear. Extensive neurolysis with subsequent free muscle flap coverage, a new surgical procedure for neuropathic pain in the upper extremity, can be performed as a final option to establish pain reduction. All consecutive patients who received extensive microsurgical neurolysis with subsequent free muscle flap for persistent neuropathic pain in the upper extremity between 2007 and 2014 were identified. Patient-reported upper extremity function and QoL were assessed using three questionnaires (36-item short-form health survey (SF-36), the disabilities of the arm, shoulder, and head questionnaire, and the Michigan hand outcomes questionnaire). Fifteen patients were identified; 80% had neuropathic pain in the upper extremity due to nerve injury and a median of 3.0 previous surgeries (range 1-6). Sixty-seven percent developed some kind of complication, flap loss occurred in 22%, and all received a new free flap (one failed again). At last follow-up, pre- and postoperative visual analog scale (VAS) scores significantly differed (p = 0.002), and the median VAS at last follow-up was 1.5. Ten patients (67%) responded to the questionnaires after a median follow-up of 5.7 year (range 2.6-7.3 years). Patients on average reported poorer SF-36 "Physical Component Score" (PCS) and "Bodily Pain" compared to Dutch norms. Forty percent of patients reported still having always (very) severe pain. However, 64% had a postoperative decrease of at least 3.0 on VAS. Extensive neurolysis with free muscle flap coverage for persistent neuropathic pain in the upper extremity showed a positive effect on pain reduction on short-term follow-up, and also at five-year follow-up. The impact of pain on functional outcomes remained. Nevertheless, 60% of the patients still experience sufficient pain reduction.