Chiari Malformation Type 1 and Semi-Sitting Position-A Suitable Alternative for Patients with High BMI

Chiari I malformation results from a mismatch between the posterior fossa bones and neural components. Management usually relies on surgical treatment. Despite being the most common assumed positioning, the prone position can be challenging in high body mass index (BMI) patients (>40 kg/m²).

Between February 2020 and September 2021, 4 consecutive patients with class III obesity underwent posterior fossa decompression. The authors describe nuances of the positioning and perioperative details.

No perioperative complications were reported. These patients are at a lower risk of bleeding and increased intracranial pressure as a consequence of low intra-abdominal pressure and venous return. In this context, the semi-sitting position, with the aid of accurate monitoring for venous air embolism, seems to be an advantageous surgical position in this group of patients.

We present our results and technical nuances on positioning high BMI patients for posterior fossa decompression using a semi-sitting position.