A Novel Surgical Technique for Post-traumatic Syringomyelia Progressing to the Medulla Oblongata: Evidence of Upward Drainage of Central Canal Fluid Within the Spinal Cord

BACKGROUND AND OBJECTIVES: The exact pathways of fluid outflow within the central canal (CC) of the spinal cord are not completely understood. The best management approach for patients with post-traumatic syringomyelia that progresses to the cranial end of the CC, also known as post-traumatic syringobulbia (PT-syringobulbia), is still a topic of debate. This study aims to introduce a new surgical indication for the foramen magnum and foramen of Magendie dredging (FMMD) procedure in patients with PT-syringobulbia and prospectively assess its surgical outcomes. METHODS: The study included 15 consecutive patients with symptomatic PT-syringobulbia who underwent the FMMD procedure and 20 patients who underwent traditional arachnolysis. The surgical procedure included decompression of the foramen magnum, removal of all potential intradural factors, and clearance of any possible obstructions at the foramen magnum and the foramen of Magendie. The major presenting symptoms or signs were assessed in terms of symptom improvement, stabilization, or deterioration. Preoperative MRI and postoperative MRI were used to assess syringobulbia resolution. The mean follow-up period was 24 months (range 12-60 months). RESULTS: Twelve patients showed clinical improvement, and 3 were stable. The mean length of the syrinx observed on preoperative MRI was 17.3 spinal levels, and the mean syringobulbia/medulla oblongata index was 69%. The mean syringobulbia/medulla oblongata index observed on postoperative MRI was 29%. The values were significantly lower than the preoperative values ( P < .01). Statistical analysis revealed no significant differences in age, sex, or initial clinical/radiological presentation between the FMMD and arachnolysis groups ( P > .05). However, the FMMD group showed superior outcomes compared with the arachnolysis group, including better clinical improvement, syringomyelia regression, lower complication rates, and reduced revision surgery rates ( P < .01). CONCLUSION: FMMD emerges as a potentially safe and effective surgical strategy for post-traumatic syringobulbia by restoring physiological fluid outflow through the cranial end of CC in midterm follow-up.