Intravascular ultrasound-guided internal carotid artery stenting

The study was aimed at demonstrating efficacy and feasibility of intravascular ultrasound during internal carotid artery stenting for assessment of atheromatous plaque protrusion through a stent.

Over the period from October to December 2018, the specialists of our Centre performed a total of 90 internal carotid artery stenting procedures in 83 patients (of these, 7 patients underwent bilateral staged stenting of both internal carotid arteries) using intravascular ultrasound in order to assess intraoperative protrusion of an atherosclerotic plaque through the implanted stent. The patients' age varied from 42 to 87 (mean 68.6±6.9) years. Symptomatic lesions of internal carotid arteries were revealed in 14 (16.9%) operated patients and asymptomatic lesions in 69 (83.1%). The degree of stenosis varied from 60% to 90% according to the findings of preliminary duplex ultrasonography and was subsequently confirmed by the results of multislice computed tomography or selective angiography. The assessment of the patients' neurological status, as well as duplex ultrasonography of brachiocephalic arteries were performed at a scheduled follow-up visit on day 30 after discharge from hospital.

The technical success of stenting was achieved in 100% of patients. According to the findings of intravascular ultrasound, plaque protrusion was observed in eight (8.8%) stented patients. Among them, six (6.6%) were free from angiographic signs of protrusion and only two (2.2%) had apparent angiographic signs of protrusion. During the early postoperative period, transient ischaemic attack was identified in four (4.4%) cases. One (1.1%) patient was found to develop ST-segment elevation acute myocardial infarction 24 hours after internal carotid artery stenting, followed by large hemispheric stroke on the side of stenting revealed on postoperative day 3. Nine (10%) patients according to the findings of intravascular ultrasound were diagnosed as having incomplete stent apposition after postdilatation, with the absence of such signs on angiography.

Intravascular ultrasound during carotid stenting provides a more accurate assessment of such an event as atherosclerotic plaque protrusion through a stent's cells. At the same time, IVUS-guided assessment of the intraoperative outcome may prevent the risk for the development of stroke in the early postoperative period. Besides, intravascular ultrasound allows a more detailed assessment of stent apposition and the degree of stent expansion in order to optimize and improve the remote results of the operation.