An efficacy analysis of posterior fossa decompression techniques in the treatment of Chiari malformation with associated syringomyelia.

A retrospective study of the efficacy of posterior fossa decompression (PFD) was carried out in 132 patients with Chiari malformation (CM) with associated syringomyelia (SM). Of these 132 patients, 69 received extended PFD (large craniotomy group), and the other 63 patients received only local PFD (small craniotomy group). At the short-term postoperative evaluation (1-4 weeks) the extended PFD appeared to be more effective than the local PFD (p<0.05). However, there was no significant difference in long-term analysis (6 months-11 years) (p>0.05). In the large craniotomy group, there was no difference between the short-term and long-term efficacy (p>0.05). However, in the small craniotomy group, long-term efficacy clearly improved (p<0.05). Furthermore, patients who had undergone local PFD exhibited more obvious radiological improvement of SM (p<0.05) and fewer postoperative complications compared to patients undergoing extended PFD (p<0.05). Therefore, local PFD is preferable for the surgical treatment of CM with associated SM.