Purpose
The purpose of this study was to determine the early failure rate of percutaneous epidural neuroplasty (PEN) that led to subsequent decompressive lumbar surgery. We also assessed the limits of spinal pain management by using the current PEN technique.
Materials and Methods
We classified 1763 cases according to their diagnoses and radiological findings. Patients who underwent subsequent open surgery when PEN failed to improve or aggravated their symptoms were included.
Results
All 37 patients underwent open decompressive surgery within 3 months after PEN. There were 18 in the intracanalicular focal herniation category, 11 in intracanalicular broad based herniation category, and 8 in foraminal category; the early failure rates were 1.7%, 1.9%, and 5.6%, respectively. There was no significant statistical difference between the intracanalicular categories with regard to failure rate, but the foraminal category had a higher rate of failure than that of intracanalicular categories (p<0.05). Moreover, there were 11 cases in intracanalicular categories that experienced deterioration or new symptoms due to posterior longitudinal ligament rupture or fragment migration. Among these, there were 9 cases (82%) with preexisting intracanalicular migrating fragments.
Conclusion
PEN with targeted drug delivery may be an effective treatment for low back pain and/or radiculopathy. However, its early failure rate is at least 2.1%, and the presence of intracanalicular migrating fragments or symptomatic foraminal lesions are predictors of poor outcome. Patients must be carefully selected on the basis of thorough radiologic reviews to improve the rate of satisfactory PEN outcomes.