Factors contributing improvement of syringomyelia and surgical outcome in type I Chiari malformation.
OBJECTIVE
The aim of our study was to compare pre- and postoperative radiologic data of posterior fossa and the improvement of syringomyelia after posterior fossa decompression (PFD) with and without tonsillar management in Chiari type capital I, Ukrainian malformation (CM-I).


METHODS
A retrospective analysis was made of all patients who underwent PFD between Oct 1991 and March 2007 for CM-I. Fifty-seven patients treated for CM-I at a single institution were included in the study. Patients were divided into two groups according to the procedures used during their PFD: PFD vs. PFD with tonsillar management. To determine whether the tonsillar management or changes of posterior fossa volume relate with surgical outcome, we measure posterior fossa size and syringomyelia pre- and postoperatively using magnetic resonance imaging.


RESULTS
Forty patients (70.2%) received PFD and 17 patients (29.8%) received PFD with tonsillar management. The length of syringomyelia affected improvement of syringomyelia (alteration rate, A-rate). Clinical symptoms, craniectomy size, syringomyelia type, and the surgeon's specialty did not affect A-rate. Tonsillar management has no significant effect on improvement of syringomyelia. Four patients need repeated surgery due to recurrence.


CONCLUSIONS
We have shown that tonsillar management do not lead to improve A-rate, and the radiologic changes of posterior fossa volume do not relate with radiologic improvement of syringomyelia. PFD without tonsillar management is sufficient to improve syringomyelia. The longer syrinx, the more A-rate improve in our study. However, a wider craniectomy is unrelated to A-rate. In cases of recurrent patients, we obtained good results with tonsillar management or syringosubarachnoid shunt.
Park
Young Seok
YS
Department of Pediatric Neurosurgery, Brain Research Institute, College of Medicine, Yonsei University, Seoul, South Korea.
Kim
Dong-Seok
DS
Shim
Kyu-Won
KW
Kim
Jung-Hee
JH
Choi
Joong-Uhn
JU
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001139:Arnold-Chiari Malformation / Q000150:complications / Q000601:surgery*; D002531:Cerebellum / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D003388:Cranial Fossa, Posterior / Q000601:surgery*; D003399:Craniotomy; D019299:Decompression, Surgical; D005260:Female; D006257:Head / Q000473:pathology / Q000601:surgery; D006801:Humans; D007223:Infant; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013595:Syringomyelia / Q000209:etiology / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult