Tortuosity of ACOM and ACA Aneurysms with Flow Diversion Effects

Introduction/Purpose The anterior communicating artery (ACOM) is the most common site for intracranial aneurysms (1). Multiple treatment paradigms exist for ACOM aneurysms including clipping, coiling, and, more recently, flow diversion (2,3). Understanding how parent vessel tortuosity influences endovascular treatment for aneurysms may help predict procedural challenges. Previous studies have shown that longer radiation exposure and difficulty of device deployment can be attributed to more tortuous arteries (4,5). Although tortuosity has been studied in several vascular territories, its role in the anterior cerebral artery (ACA) and ACOM region has not been extensively investigated (5‐9). This study evaluates whether ACA tortuosity is associated with procedural complexity, fluoroscopy and procedural time, or procedural complications during flow diversion for ACOM and A1/A2 junction aneurysms. Materials/Methods Demographic information, comorbidities, procedural details, and complications were prospectively collected on 733 patients treated for cerebral aneurysms between January 2020 and June 2025. Patients treated with flow diversion for ACOM or A1/A2 junction aneurysms were included. Complications were categorized as intraoperative (vasospasm, stent thrombosis) or delayed (stroke, vasospasm). Tortuosity index (TI) was calculated using established methods, defined as the ratio of curved (absolute) to straight‐line vessel length (6‐8). Pre‐interventional A1 segments were measured from the ICA terminus to the A1/A2 junction. Absolute lengths were traced along the vessel's curvature, while straight‐line lengths measured the linear distance between start and end points. Logistic regression assessed whether TI predicted procedural complexity or complications, and linear regression evaluated relationships between TI and procedural or fluoroscopy time. Extreme outliers were removed. Results Of the 733 aneurysms examined, 56 patients met inclusion criteria. The sample included 36 females (65.3%), 49 white patients (87.5%), 42 with hypertension (75.0%), 18 with hyperlipidemia (32.1%), and 27 current smokers (48.2%). The location of the aneurysms was at the ACOM in 46 patients and involved the distal A1/A2 junction in 10. The average aneurysm neck size was 3.9 mm (±1.8), and the average aneurysm size was 5.4/4.7 mm (±2.5/2.4) (width/height). Absolute artery length was 14.2 mm (±3.0) with a straight‐line length of 13.0 mm (±2.7). TI was significantly associated with procedure duration (p = 0.01) and fluoroscopy time (p = 0.04), with mean times of 120.8 and 36.2 minutes, respectively. TI did not predict intraoperative (OR = 3.9, n = 4) or delayed complications (OR = 5.9, n = 4) in logistic regression (all p > 0.05). Procedural complexity was low, with only one patient (1.8%) requiring balloon angioplasty and none requiring device removal. Conclusion Patients with more tortuous A1 segments experienced significantly longer procedure and fluoroscopy times, without a corresponding increase in intraoperative or delayed complication rates, as shown by regression analyses. TI may predict procedural complexity, and this can be taken into consideration when planning for a case. Perhaps this pre‐operative consideration of TI can be used to predict the complexity of other neurointerventional procedures, such as coil embolization or thrombectomy. Increased procedure duration and fluoroscopy time carry long‐term health risks for both patients and operators, so TI may be an important factor for risk reduction (10‐12).