The role of contrast-enhanced transcranial color-coded real-time sonography combined with the common carotid artery compression test in preoperative evaluation of anterior communicating artery patency in patients with insufficient temporal bone windows.

OBJECTIVE: The purpose of the study was to evaluate the anterior communicating artery (ACoA) patency in patients with suboptimal temporal bone windows who were scheduled for carotid endarterectomy (CEA), using contrast-enhanced transcranial color-coded real-time sonography (CE-TCCS) combined with common carotid artery compression (CCC) test. METHOD: A prospective analysis was conducted on 116 patients with suboptimal temporal bone windows who exhibited symptomatic carotid artery stenosis (sCAS). The display rates of intracranial circle of Willis (CoW) including anterior cerebral artery (ACA), middle cerebral artery, and posterior cerebral artery, were analyzed based on TCCS and CE-TCCS data. The functional patency of the ACoA was assessed by CE-TCCS with and without the CCC test, and the results were compared with the anatomical patency determined by CTA. RESULT: The visualization rates of CoW were significantly improved in CE-TCCS (p < 0.001). CE-TCCS excluded 24 patients due to unilateral absence of the ACA-A1 segment. We assessed the patency of the ACoA in 92 patients. With CTA as the anatomical reference standard, CE-TCCS combined with CCC test yielded 94.67% sensitivity, 100% specificity and positive predictive value, 80.95% negative predictive value, and 95.65% overall diagnostic accuracy. Compared with CTA, CE-TCCS combined with CCC test showed no significant difference (p = 0.125) and excellent consistency (Kappa = 0.868, 95% CI: 0.743-0.993, p < 0.001), whereas standalone CE-TCCS differed significantly from CTA (p < 0.001) with poor consistency (Kappa = 0.126, 95% CI: 0.053-0.199, p = 0.013). The functional ACoA patency rate detected by CE-TCCS combined with CCC test was 77.2%, while 70.4% of patent cases were missed by CE-TCCS alone. CONCLUSION: CE-TCCS significantly improve the display rate of intracranial CoW. CE-TCCS combined with the CCC test can serve as a reliable technique in preoperative evaluation of ACoA patency in patients with inadequate temporal bone windows.