A single pre-post study has assessed the effectiveness of S-S Bypass in 20 individuals (mean age=47.3 years, 19 males) with SCI-related syringomyelia (Hayashi et al. 2013). The mean time since SCI was 126 months (range 2-336 months) and they were followed up, on average, for 48.2 months (range 12-93 months). Post-surgery, 12 patients showed improvements, four remained stable, and four showed signs of deterioration. Three of the four patients who demonstrated deterioration underwent a shunt replacement; two improved and one remained unchanged. There was no significant correlation between ASIA scores at baseline and follow-up. Finally, no patient experienced a CSF leak that needed treatment (Hayashi et al. 2013). The authors conclude that S-S Bypass is not only an effective method in treating syringomyelia but that it may be associated with better clinical results than those of other surgical interventions (e.g., shunts, cordectomy). Hayashi et al. (2013) state that S-S Bypass can be conducted without myelotomy therefore reducing the risk of neurological damage and does not usually require performing arachnoid lysis which avoids the possibility of scarring. Although there is a risk of re-scarring or re-tethering, the bypass tubes prevent the obstruction of CSF flow caused by re-scarring (Hayashi et al. 2013). However, a potential methodological concern of this study was the use of a subjective grading approach to patient improvement, stabilization and deterioration. Further investigation from multiple studies is required to make conclusions as to its clinical effectiveness.
There is level 4 evidence (from one pre-post study; Hayashi et al. 2013) that subarachnoid-subarachnoid bypass may improve motor and bladder functioning post SCI-related syringomyelia.
Subarachnoid-subarachnoid bypass may improve motor and bladder functioning post SCI-related syringomyelia.