Intraoperative distal MCA flow velocity patterns during bypass procedures in Moya Moya disease patients- A prospective study.

This study aims to investigate the differences in intraoperative distal middle cerebral artery (MCA) blood flow velocities under inhalational (Isoflurane, Sevoflurane, and Desflurane) versus intravenous anesthesia in patients with Moya Moya Disease undergoing direct revascularization procedures.

The primary objective is to compare intraoperative distal MCA cerebral blood flow velocities in patients receiving inhalational versus intravenous anesthesia during STA-MCA bypass surgery. Secondary objectives include observing changes in distal MCA mean blood flow volume before and after micro-anastomosis, comparing intraoperative mean distal MCA blood flow velocity changes during hypercapnia and hypocapnia, evaluating changes in mean distal MCA blood flow velocity following blood pressure augmentation, and assessing changes in regional cerebral oxygenation before and after anastomosis.

The study will be conducted as a prospective observational open-labeled non-randomized interventional comparative study at the National Institute of Mental Health and Neurosciences, Bengaluru, over a period of 2 years. Patients meeting inclusion criteria, aged 2 to 65 years with Moya Moya Disease undergoing STA-MCA bypass surgery, will be included. Exclusion criteria include pregnant women, those with modified surgical procedures, and patients with Ischaemic Heart Disease.

Patients will be divided into four groups based on anesthesia type: Isoflurane, Sevoflurane, Desflurane, and Propofol. Intraoperative monitoring will include transcranial Doppler (TCD) recordings, measurement of regional cerebral oxygenation (rSO2), and interventions to adjust carbon dioxide levels and blood pressure. Data collection will include variables such as blood flow velocities, vessel diameter, FiO2, EtCO2, MAP, and MAC.

Sample size estimation suggests a total of 60 patients (15 in each group) to detect clinically significant changes. Statistical analysis will be performed using IBM SPSS Statistics, with RMANOVA utilized for intergroup comparisons. A significance level of p<0.05 will be applied.

Overall, the study aims to provide insights into the impact of anesthesia type on intraoperative cerebral blood flow dynamics in Moya Moya Disease patients undergoing direct revascularization surgery.