2025 Proffered Presentations
S313: CONSIDERATIONS AND COMPLICATIONS ASSOCIATED WITH CRANIOTOMIES IN THE SITTING POSITION: A 10-YEAR SINGLE-CENTER RETROSPECTIVE SERIES
Ehsan Dowlati, MD; Danielle Golub, MD, MSCI; Alon Kashanian, MD; Sabastian Hajtovic; Alexander F Kuffer, MD, PhD; Kyriakos Papadimitriou, MD; Amir R Dehdashti, MD; North Shore University Hospital
Objective: The sitting position has historically offered neurosurgeons important advantages including improved venous drainage and clearing of blood from the operative field due to gravity, and a reduced need for cerebral or cerebellar retraction, especially for the surgical treatment of posterior fossa pathologies. Nonetheless, operating in the sitting position has widely fallen out of favor due to the perceived risk of positioning-related complications, namely, venous air embolism (VAE). The objective of this study was to describe the incidence and predictors of complications related to performing craniotomies in the sitting position in a contemporary series of patients undergoing surgery for skull base and cerebrovascular lesions.
Methods: Retrospective chart review of a prospectively collected data database of adult patients who underwent surgery in the sitting position by a single surgeon from 2014 to 2023 was performed. Each patient who underwent surgery in the sitting position underwent a protocolized screening process to rule out a patent foramen ovale via transthoracic or transesophageal echocardiogram, and a thorough cardiopulmonary risk assessment by an anesthesiologist preoperatively. All instances of postoperative tension pneumocephalus, subdural hemorrhage, and intraoperative VAE were recorded along with their severity and any related complications. Length of stay in the intensive care unit (ICU) and overall hospitalization length were also analyzed. Patients without at least 1 month of postoperative clinical follow-up were excluded.
Results: A total of 97 patients met eligibility criteria and were included for analysis. A significant majority, 80 patients (82%), had undergone a retrosigmoid or extended retrosigmoid/far lateral craniotomy for resection of a vestibular schwannoma. Intraoperative VAE (assessed as a sudden decrease in end-expiratory CO2 greater than 4mmHg, characteristic sounds on precordial doppler, or any sign of intracardiac air on transthoracic echocardiogram) was observed in 8 cases (8.2%). In five of these cases, the effects of the VAE were transient, without hemodynamic consequence, and resolved without intervention. Clinically significant VAE occurred in three patients (3.1%); in all three cases the required changes in hemodynamic management necessitated early interruption of surgery. While one of these patients did not require additional hemodynamic support postoperatively, the two other patients developed significant acute respiratory distress syndrome (ARDS), resulting in prolonged ICU stays. One patient also required extracorporeal membrane oxygenation (ECMO) for several days. In terms of other complications, there was one case of bifrontal tension pneumocephalus that resulted in an acute subdural hemorrhage requiring hemicraniectomy for evacuation, and two patients who experienced transient lower extremity neuropathies that resolved by outpatient follow-up.
Conclusions: Although surgery in the sitting position offers significant advantages for posterior fossa craniotomies in terms of a clear operative field, improved surgical ergonomics, and less reliance on brain retraction, the risk of VAE is not insignificant even at an experienced center. Thorough preoperative screening as well as intraoperative precautions including the use of a precordial doppler and an experienced anesthesia team should be undertaken. Patients should be advised of these risks before agreeing to pursue surgery in the sitting position.