A critical appraisal of drainage in syringomyelia

The use of drains in the treatment of syringomyelia has a simple and immediate appeal and has been practiced widely since the report of Abbe and Coley over 100 years ago. Good short-term results have been claimed in the past, but long-term outcome is largely unknown. An experience in Birmingham, England is reviewed in which 73 patients who had had some form of syrinx drainage procedure performed were subsequently followed up. In these cases, a total of 56 syringopleural and 14 syringosubarachnoid shunts had been inserted. Ten years after the operations, only 53.5% and 50% of the patients, respectively, continued to remain clinically stable. A 15.7% complication rate was recorded, including fatal hemorrhage, infection, and displacement of the drain from the pleural and syrinx cavities. At second operation or necropsy, at least 5% of shunts were discovered to be blocked. The effect of other drainage procedures that do not use artificial tubing, such as syringotomy and terminal ventriculostomy, was analyzed but found not to offer any substantial benefit. These results indicate that drainage procedures are not an effective solution to remedying the progressive, destructive nature of syringomyelia. It is suggested that, rather than attempting to drain the syrinx cavity, disabling the filling mechanism of the syrinx is more appropriate. Most forms of syringomyelia have a blockage at the level of the foramen magnum or in the subarachnoid space of the spine. Surgical measures that aim to reconstruct the continuity of the subarachnoid space at the site of the block are strongly recommended. Lowering the overall pressure of the cerebrospinal fluid is advocated when reestablishment of the pathways proves impossible. Syrinx drainage as an adjuvant to more physiological surgery may have a place in the treatment of syringomyelia. If two procedures are done at the same time, however, it is difficult to ascribe with certainty a success or failure, and it is suggested that the drainage procedure be reserved for a later attempt if the elective first operation fails.