Dorsal root entry zone incision for pain induced by brachial plexus injury: an analysis of curative effect and complications

Objective To evaluate the efficacy and safety of dorsal root entry zone (DREZ) incision for pain induced by brachial plexus injury. Methods A cohort study was performed in 41 consecutive patients with pain induced by brachial plexus injury treated with DREZ incision from July 2005 to December 2007. Of all, 19 patients were amputated and had phantom limb sensation. Oral pain relief (0%-100%) and complications were followed up by one professional doctor. Oral pain relief rate ≥50% was considered satisfactory outcome. Results The proportion of patients with satisfactory pain relief was 90% (37/41), 81% (30/37), 77% (24/31) and 70% (16/23) at 2 weeks, 3 months, 6 months and last follow-up (over one year) after surgery. At last follow-up, 15 out of 16 patients with over 10 years of pain duration got satisfactory pain relief; while only 16 out of 25 patients with less than 10 years of pain duration got satisfactory pain relief (x2 =4.682, P =0.030). In 16 amputees who were followed up for more than three months, seven patients with alteration of phantom limb sensation got satisfactory pain relief, while only four out of nine patients without alteration of phantom limb sensation got satisfactory pain relief. Among 37 patients followed up for more than three months, severe neurological defects were found in three patients including one with mild motor disturbance in the ipsilateral lower limb and two with severe sensory disturbance in the ipsilateral lower limb. Conclusions DREZ incisions are effective and safe neurosurgical procedure for relieving pain induced by brachial plexus injury. The possible predictive factors of better outcome are the long preoperative pain duration and postoperative phantom limb sensation among amputees. Key words: Pain, intractable;  Brachial plexus;  Dorsal root entry zone