# Posterior Fossa Decompression Versus Syringo-Subarachnoid Shunt for Chiari I-associated Syringomyelia: A Systematic Review

## TL;DR

This review compares two surgeries for treating syringomyelia caused by Chiari I malformation, finding that posterior fossa decompression is more effective and durable.

## Contribution

The study systematically compares the effectiveness and outcomes of two surgical treatments for Chiari I-associated syringomyelia.

## Key findings

- Posterior fossa decompression with duraplasty achieved 80% syrinx resolution and 60-100% clinical improvement.
- Syringo-subarachnoid shunting provided 70-85% syrinx reduction but had variable long-term outcomes.
- Arachnoid-preserving techniques reduced cerebrospinal fluid-related complications.

## Abstract

Chiari malformation type I (CM-I) is a downward herniation of the cerebellar tonsils through the foramen magnum, frequently resulting in syringomyelia, which affects up to 75% of patients and remains a major source of neurological morbidity. This systematic review evaluated surgical outcomes for patients with CM-I-associated syringomyelia. Fifteen studies met the inclusion criteria, and the majority demonstrated high methodological quality. Posterior fossa decompression with duraplasty achieved approximately 80% syrinx resolution and 60-100% clinical improvement. Arachnoid-preserving techniques reduced CSF-related complications. Syringo-subarachnoid shunting provided 70-85% syrinx reduction after failed decompression but showed variable long-term outcomes. Posterior fossa decompression with duraplasty remains the most effective and durable treatment, while shunting is reserved for persistent or recurrent cases following the decompression.