Table 2.
Cumulative proportion of patients with no changes in pain relief effect after the junctional dorsal root entry zone microcoagulation treatment of pain caused by brachial plexus avulsion (Kaplan-Meier table)*
| No. of patients |
Cumulative proportion of patients with |
||||
|---|---|---|---|---|---|
| Interval between the surgery and the pain relief evaluation (years) | with no changes in pain relief effect | with increased pain | excluded from follow-up | unchanged pain relief (%) | standard error of cumulative proportion (%) |
| Total (n = 26) | |||||
| 0 | 26 | 4 | 0 | 100 | 0 |
| 1 | 22 | 4 | 6 | 84.6 | 7.1 |
| 3 | 12 | 5 | 1 | 66.8 | 9.7 |
| 5 | 6 | 0 | 6 | 37.8 | 11.2 |
| Pain duration before operation ≤5 y: | |||||
| 0 | 13 | 4 | 0 | 100 | 0 |
| 1 | 9 | 2 | 4 | 69.2 | 12.8 |
| 3 | 3 | 3 | 0 | 49.4 | 14.9 |
| 5 | 0 | ||||
| Pain duration before operation >5 y:† | |||||
| 0 | 13 | 0 | 0 | 100 | 0 |
| 1 | 13 | 2 | 2 | 100 | 0 |
| 3 | 9 | 2 | 1 | 83.3 | 10.8 |
| 5 | 6 | 0 | 6 | 63.7 | 14.7 |
*Twenty-six patients assessed up to 1 year, 18 up to 3 years, and 17 up to 5 years. In case when a pain relief effect (time dependent variable) decreased (the pain increased), such a patient was excluded from the analysis in the next time interval because the pain relief effect was lost. The patients were also divided in two groups according to the pain duration before the DREZ lesion (pain duration ≤5 years and >5 years).
†Log-rank test revealed that the unchanged pain relief lasted significantly longer after the DREZ lesion in the group of patients with preoperative pain duration of >5 years (P = 0.011).