Semisitting position in neurosurgery: A 20-year experience in a tertiary center

The semisitting position offers surgical advantages for posterior fossa and pineal region procedures but remains controversial due to potential complications such as venous air embolism (VAE) and tension pneumocephalus. This study reviews a 20-year single-center experience to assess its safety, complication profile, and clinical outcomes under a standardized monitoring protocol.

This retrospective cohort study included all consecutive patients undergoing neurosurgical procedures in the semisitting position at our tertiary center from January 2004 to December 2024. Patients were monitored using a standardized protocol including precordial Doppler ultrasonography, end-tidal CO₂ monitoring, and central venous catheter placement. Patient demographics, surgical details, perioperative complications, and clinical outcomes were systematically analyzed. Venous air embolism (VAE) and other significant adverse events were specifically documented. Statistical analyses included univariate and multivariate logistic regression analyses to identify potential risk factors for complications.

A total of 244 patients underwent surgery in the semisitting position, with a mean age of 43.8±18.4 years. The most common surgical localizations were the parietal and occipital regions, followed by the posterior fossa. The incidence of VAE was 4.5% (n=11), including one fatal cerebral infarction. Other complications occurred in 3.6% of cases, including tension pneumocephalus (1.6%), neurological deficit, cerebrospinal fluid leakage, postoperative seizure, myocardial infarction, and ischemic infarction (each 0.4%). Multivariate analysis did not identify significant predictors of complications.

The semisitting position remains a safe and effective neurosurgical approach when executed with rigorous protocols and vigilant monitoring. With careful management, these risks can be effectively mitigated, underscoring their continued utility in suitable cases, particularly for surgeries involving the posterior fossa and pineal region.