To compare risks and benefits of posterior fossa decompression surgery with and without duraplasty among patients with Chiari malformation type I and syringomyelia
|Randomized controlled trial
|162 children and young adults under age 22 with Chiari malformation type I with ≥5 mm tonsillar ectopia and syrinx diameter between 3 mm and 9 mm
- Posterior fossa decompression with duraplasty
- Posterior fossa decompression without duraplasty
Primary: intra-operative and postoperative surgical complications, need for surgical procedures to manage complications
Secondary: treatment efficacy based on symptoms, neurological findings, syrinx size, and need for revision decompression surgery; quality of life
|6-month follow-up for primary outcomes
Chiari malformation type I is a condition affecting children and young adults in which the cerebellum descends into the spinal canal, putting pressure on important structures of the brain. It is associated with syringomyelia, a cyst that damages the spinal cord and causes symptoms such as pain, weakness, or stiffness. Surgical decompression, which relieves pressure, is the usual treatment, but doctors use two different methods.
This cluster randomized controlled trial compared the effect of posterior fossa decompression with and without duraplasty among patients with Chiari malformation type I and syringomyelia on surgical complications, treatment effectiveness, and quality of life.
Researchers randomly assigned treatment centers to provide decompression surgery with or without duraplasty. Patients received the surgery assigned to their center. Duraplasty involves opening and expanding the dura with an autologous graft or dural substitute.
The study included 162 children and young adults with Chiari malformation type I and syringomyelia receiving treatment at one of 38 centers. Among patients, 81% were White, 9% were Black or African American, 5% were more than one race, 4% did not report race, and less than 1% were Asian, American Indian, or Alaska Native; 9% were Hispanic or Latino. The average age was 10, and 54% were female.
At visits before surgery and 1 to 6 weeks, 3 to 6 months, and 12 to 24 months later, researchers collected information about complications and symptoms and performed clinical exams. Patients completed surveys about quality of life. Researchers examined noninferiority of decompression without duraplasty based on a predetermined margin of no less than 20% lower clinical improvement than with duraplasty. Researchers then examined superiority of decompression with and without duraplasty.
Parents of children with Chiari malformation type I and patient advocacy organizations helped design the study.
At six months, the odds of intra-operative and postoperative complications did not differ significantly between patients receiving decompression with and without duraplasty.
At one year, decompression alone was noninferior to decompression with duraplasty for clinical improvement. However, decompression with duraplasty was superior to decompression alone for syrinx regression (p=0.0001).
Patients without duraplasty were more likely to need surgical revision compared to patients with duraplasty (p=0.045). Quality of life did not differ significantly between patients with and without duraplasty.
Doctors may not have enrolled patients with more severe disease in the study. Results may differ for these patients.
Conclusions and Relevance
In this study, complication rates and quality of life did not differ among patients with Chiari malformation type I and syringomyelia who had decompression surgery with and without duraplasty. Decompression without duraplasty was noninferior for clinical improvement; however, decompression with duraplasty was superior for syrinx regression.
Future Research Needs
Future research could examine the effects of decompression with and without duraplasty on longer term neurodevelopmental outcomes among children with Chiari malformation type I and syringomyelia as they age.