A One-Finger-Width "Baklava Dough" Dural Thinning Technique in Dura-Preserving Posterior Fossa Decompression for Chiari Type I Malformation.

Abstract

The optimal surgical extent of posterior fossa decompression in Chiari type I malformation remains controversial. This study aimed to evaluate the clinical and radiological outcomes of a modified dura-splitting technique based on controlled thinning of the meningeal layer. This modification, referred to as the "One-Finger-Width 'Baklava Dough' Dural Thinning Technique," involves performing a minimal skin incision of one-finger width (about 2 cm), followed by splitting the dura into thin layers and microscopically thinning the meningeal layer to a thickness comparable to baklava dough, allowing visualization of CSF pulsation through the thinned dura. A total of 32 consecutive adult patients with Chiari type I malformation who underwent posterior fossa decompression using this technique between 2018 and 2024 were retrospectively analyzed. Clinical outcomes were evaluated using neurological examination, VAS scores, and CCOS-PROM, while radiological outcomes included measurements of tonsillar herniation and syringomyelia parameters. Syringomyelia was present in 13 patients (41%), and radiological regression was observed in 12 of these patients (92%). The mean syrinx diameter decreased from 8 ± 3 mm to 4 ± 3 mm (p = 0.0017). Significant reductions were observed in VAS scores for headache, neck pain, back pain, and arm pain (p < 0.05). No postoperative CSF fistula, pseudomeningocele, wound infection, or reoperation occurred. The "One-Finger-Width 'Baklava Dough' Dural Thinning Technique" appears to be a safe and feasible surgical approach that preserves dural integrity and is aimed at improving posterior compliance and restoring physiological CSF circulation at the craniospinal junction.