Natural History of Conservatively Managed Spinal Cord Cavernous Malformation: A Meta-analysis

Introduction: Spinal cord cavernous malformations (SCCMs) are rare lesions believed to have high rates of debilitating hemorrhages, often requiring complex treatment. While many SCCMs are resected surgically at symptomatic presentation, the natural history of many conservatively managed or untreated SCCMs remains far less understood. In this meta-analysis, we aim to assess the natural history of conservatively managed SCCMs and their risk of hemorrhage.

Methods: Preferred reporting items for systematic reviews and meta-analysis guidelines (PRISMA) were utilized in this work. Primary studies in English focusing on conservatively managed SCCMs with over 20 patients were included. We extracted demographic data, follow-up lengths, lesion characteristics and locations, symptoms, and hemorrhagic complication rates. A random-effects meta-analysis was conducted to estimate the overall event rate per patient-year across studies, accounting for heterogeneity.

Results: A total of 2457 studies were screened, of which 116 were reviewed for full text. From this, nine studies were included, resulting in 822 patients with 815 SCCMs, with a mean follow-up of 41.5 months. The mean age of patients was 52 years and 43.8% were female. The mean lesion size was 10.5 mm and locations were 36.7% cervical, 51.9% thoracic, and 11.4% lumbar. The most common symptoms were pain (47.9%), weakness (63.4%), sensory deficits (77.9%), and bowel/bladder dysfunction (42.9%). A total of 647 hemorrhagic events occurred over 18,692 person-years, which is an average of 3.1 events per 100 person-years (95% CI 2.82–3.33). The five-year cumulative risk of hemorrhage was calculated to be 14.41%.

Conclusion : Conservatively managed SCCMs report an annual hemorrhage risk of 3.1%, presenting mostly in thoracic regions with significant sensory deficits and weakness. Greater prospective cohorts of conservatively managed patients would be beneficial to further elucidating the natural course of SCCMs.