Safety and effectiveness of spinal dural defect repair in the management of superficial siderosis: A systematic review and patient-level analysis

Objective: Superficial siderosis (SS) is a disabling neurodegenerative condition that may be caused by spinal dural defects. Surgical repair is increasingly performed, however clinical outcomes remain unclear. Methods: A systematic search of PubMed, MEDLINE, and EMBASE was conducted (inception to February 2020). Studies reporting cases of (i) superficial siderosis, (ii) spinal dural defect, (iii) and surgical closure of the defect were included. Demographic characteristics, clinical presentation, operative technique and clinical outcome were extracted for patient-level analysis. Results: A total of 26 publications were included, which reported 38 patients with a median age of 58 years, and a male predominance (78.9 %). Ataxia (85.7 %) and hearing loss (80.0 %) were the most common presenting symptoms. The causative dural defect was most commonly ventral in location (91.7 %) and most commonly identified by CT myelography (48.6 %). Operative technique was highly variable and included primary suture, fibrin glue, dural substitute, or tissue (fat or muscle) graft. Clinical improvement was reported in 21 %, with stabilisation of symptoms in the majority (66 %) and clinical deterioration in 13.2 %. Surgical complications were observed in 7.9 %. Conclusion: In patients with superficial siderosis and spinal dural defect, operative closure leads to improvement or stabilisation of symptoms in the vast majority (87%) of patients.