title: Reevaluation of syringosubarachnoid shunt for syringomyelia with Chiari malformation.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effectiveness of syringosubarachnoid (S-S) shunting for syringomyelia with Chiari malformation. The authors describe the technical methods of performing the S-S shunt and the clinical results, including shunt malfunction.
  
  
  METHODS
  Forty-nine patients underwent S-S shunting. These patients were divided into three groups according to differences in the surgical technique used. Group I patients underwent laminectomy plus midline myelotomy and had a shunt tube placed in the dorsal subarachnoid space. Group II patients underwent laminectomy plus dorsal root entry zone myelotomy and had a shunt tube placed in the dorsolateral subarachnoid space. Group III patients underwent hemilaminectomy plus dorsal root entry zone myelotomy and had a shunt tube placed in the ventrolateral subarachnoid space.
  
  
  RESULTS
  Clinical results were generally satisfactory, especially in terms of pain relief, in all three groups. However, 10 patients among Groups I and II required follow-up surgery because of shunt problems; no second surgery was necessary for any patient in Group III.
  
  
  CONCLUSIONS
  The S-S shunt was very effective in deflating the syrinx, and the clinical results were satisfactory. Therefore, even though foramen magnum decompression is a very effective treatment, S-S shunting should be reevaluated and not rejected; it should be considered as one of the major surgical options. To prevent the possibility of cord injury by myelotomy or shunt malfunction, the dorsal root entry zone should be selected as the myelotomy site, and the shunt tube should be inserted into the ventral subarachnoid space at the cervical level.
authors.affiliation: Department of Neurosurgery, Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Iwasaki
authors.forename: K
authors.initials: K
authors.lastname: Hida
authors.forename: I
authors.initials: I
authors.lastname: Koyanagi
authors.forename: H
authors.initials: H
authors.lastname: Abe
mesh_terms: D000293:Adolescent; D000328:Adult; D001139:Arnold-Chiari Malformation / Q000175:diagnosis / Q000601:surgery*; D002557:Cerebrospinal Fluid Shunts / Q000295:instrumentation*; D002648:Child; D002675:Child, Preschool; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007796:Laminectomy; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology / Q000601:surgery; D012086:Reoperation; D013346:Subarachnoid Space / Q000473:pathology; D013595:Syringomyelia / Q000175:diagnosis / Q000601:surgery*; D016896:Treatment Outcome