- Long-Term Outcome of Patients with Spinal Dural Arteriovenous Fistula: The Dilemma of Delayed Diagnosis
Spinal dural arteriovenous fistulas (sdAVFs) usually become symptomatic in elderly men, who are affected 5 times more often than women. Symptoms caused by sdAVF comprise gait disturbances with or without paresis, sensory disturbances in the lower extremities, pain, and sphincter and erectile dysfunction. The authors retrospectively analyzed their medical data base for all patients treated for spinal dural arteriovenous fistula at their institution between 2006 and 2016. Patient age, neurologic status at the time of diagnosis, the duration of symptoms from onset to diagnosis, and follow-up information were evaluated. The extent of medullary T2WI hyperintensity, intramedullary contrast enhancement, and elongation of perimedullary veins on MR imaging at the time of diagnosis were additionally analyzed. Data for long-term outcome analysis were available in 40 patients with a mean follow-up of 52 months. The mean age at the time of diagnosis was 69 years (median, 71 years; range, 53-84 years) with a male predominance (80%). The mean duration of symptoms was 20 months. Spinal dural arteriovenous fistulas are characterized by inter-individually variable clinical presentations, which make a determination of specific predictors for long-term outcome more difficult. Fast and sufficient diagnosis might result in a better outcome after treatment. The diagnosis of spinal dural arteriovenous fistula remains markedly delayed, reflecting an ongoing lack of knowledge and awareness among treating physicians of this rare-but-serious disease.
- Number Needed to Treat with Vertebral Augmentation to Save a Life
The purpose of this study was to calculate the number needed to treat to save 1 life at 1 year and up to 5 years after vertebral augmentation. A 10-year sample of the 100% US Medicare data base was used to identify patients with vertebral compression fractures treated with nonsurgical management, balloon kyphoplasty, and vertebroplasty. The number needed to treat was calculated between augmentation and nonsurgical management groups from years 1–5 following a vertebral compression fracture diagnosis, using survival probabilities for each management approach. The adjusted number needed to treat to save 1 life for nonsurgical management versus kyphoplasty ranged from 14.8 at year 1 to 11.9 at year 5. The adjusted number needed to treat for nonsurgical management versus vertebroplasty ranged from 22.8 at year 1 to 23.8 at year 5. The authors conclude that the NNT analysis of more than 2 million patients with VCF reveals that only 15 patients need to be treated to save 1 life at 1 year. This has an obvious clinically significant impact and given that all augmentation clinical trials are underpowered to detect a mortality benefit, this large dataset analysis reveals that vertebral augmentation provides a significant mortality benefit over nonsurgical management with a low NNT.