Association between prior percutaneous epidural neuroplasty and distal postoperative spinal epidural hematoma after lumbar surgery: case series and exploratory analysis

Background Postoperative spinal epidural hematoma (SEH) is a rare but serious complication of spinal surgery. This study explored whether prior percutaneous epidural neuroplasty (PEN) was associated with symptomatic postoperative SEH occurring at a distal level, defined as completely caudal to the surgical decompression site after lumbar spinal surgery. Methods We retrospectively reviewed 232 consecutive patients who underwent 1- or 2-level lumbar spinal surgery at a single institution between 2020 and 2024. Clinical, surgical, and historical factors were compared between patients who developed symptomatic postoperative SEH requiring revision surgery and those who did not. Due to the low event rate, statistical analysis was restricted to descriptive metrics and Fisher's exact test to explore the association between prior PEN and distal SEH development. Results A total of 232 consecutive patients who underwent lumbar spinal surgery were included. Four patients (1.72%) developed postoperative SEH requiring reoperation. Notably, three of these four cases (75.0%) developed hematomas at a distal level entirely caudal to the surgical site. In the primary distal SEH analysis, all three distal cases had a history of prior PEN, compared to 16.2% (37/229) of patients who did not develop a distal SEH ( P = 0.005). Because one cell in the 2 × 2 table was zero, the exact odds ratio was unestimable. In an exploratory univariate analysis using the broader SEH endpoint, prior PEN was more frequent in the SEH group than in the non-SEH group (75.0% vs. 16.2%; Fisher's exact test P = 0.017; exact odds ratio [OR], 15.49; 95% confidence interval [CI], 1.57–152.99). Conclusions In this small series, prior PEN demonstrated an exploratory association with symptomatic, distal level postoperative SEH. Given the small number of events and wide confidence intervals, this finding should be interpreted strictly as hypothesis-generating. In symptomatic postoperative patients with a history of caudal epidural interventions, clinicians should maintain awareness and consider extending MRI coverage caudally beyond the index operated level.