A new surgical method for treating syringomyelia secondary to arachnoiditis following cervical spine surgery: the syringo-cisterna magna shunt.

PURPOSE: The 5-year postoperative failure rate of conventional shunt treatment for syringomyelia is 50%, with arachnoditis, shunt obstruction, and shunt malfunction being the most common causes. We report a new syringo-cisterna magna (SCM) shunt that allows syrinx cerebrospinal fluid (CSF) drainage normally into the cerebellomedullary cisterns through the subarachnoid space. METHODS: Between November 2012 and February 2017, six patients (mean age: 57.25 years; sex: four male and two female) received the SCM shunt. They had spinal cord injury, abscess formation after a spine operation, and cerebral meningitis-related syringomyelia (syrinx between C0 and T9), and presented sensory changes and motor weakness. Preoperatively and at 1 year postoperatively, the syrinx length and diameter were assessed using magnetic resonance imaging (MRI). Clinical outcomes were evaluated using the visual analog scale (VAS) and Japanese Orthopedic Association (JOA) scores. RESULTS: Motor weakness improved, pain subsided, and sensory disturbance resolved in all patients who returned to work within 6 weeks postoperatively. In all cases, the syrinx collapsed (length: 3.3 levels decreased; diameter: decreased from 7.90 to 4.64 mm, p = 0.046) on postoperative MRI. No patient experienced syrinx recurrence and shunt malfunction on MRI or showed spinal instability signs on plain radiography. The VAS (pre- vs post-shunt: 6.50 vs 3.83, p = 0.027) and JOA scores (pre- vs post-shunt: 10.00 vs 11.17, p = 0.167) were improved postoperatively. CONCLUSION: We developed a new shunting system allowing syrinx CSF drainage to the posterior fossa, with symptomatic improvement, minimal complications, and syrinx decrease on follow-up MRI. The SCM shunt is effective for treating syringomyelia.