[DREZ (dorsal root entry zone) surgery for the treatment of the postherpetic intercostal neuralgia]

Usefulness of screening tools in the evaluation of long-term effectiveness of DREZ lesioning in the treatment of neuropathic pain after brachial plexus injury

Background

Despite high success rate of DREZ lesioning in the treatment of intractable central pain, there is still a significant incidence of patients without satisfactory post-operative effect. The aim of the study was to evaluate the long-term effect of DREZ lesioning using both a subjective assessment using a visual analog scale (VAS) to quantify residual pain and an assessment using the screening tool (painDETECT Questionnaire, PD-Q).

Methods

DREZ lesioning was performed in 52 patients from a total 441 cases with brachial plexus injury (11.8%) during a 17-year period (1995–2011). The effect of surgery was retrospectively assessed in 48 patients.

Results

A decrease in pre-operative pain by more than 75% (Group I) was achieved in 70.8% of patients and another 20.8% reported significant improvement (Group II). The surgery was unsucessful in 8.4% (Group III). We found a significant correlation between ‘improvement’ groups from both methods of assessments. Patients from Group I usually complained of residual nociceptive pain according to PD-Q, patients from Group II typically had pain of unclear origin, and all cases those in Group III suffered from neuropathic pain, Cramer’s V = .66, P < .001. Overall, 66.7% of patients had resolved neuropathic pain, 20.8% patients had more serious complaints and may also suffer from residual neuropathic pain, while 12.5% had unresolved neuropathic pain.

Conclusion

DREZ lesioning is a safe and effective method with success rates of about 90%. PD-Q scores correspond to subjective satisfaction with the surgery and it seems to be a suitable screening tool for finding patients with residual neuropathic pain after surgery.