Gradual Expansion of a Stent to Prevent Periprocedural Complications after Carotid Artery Stenting for Vulnerable Severe Stenotic Lesions with Intraplaque Hemorrhages: A Retrospective Observational Study

Abstract

Vulnerable lesions with intraplaque hemorrhages are associated with a high incidence of complications following carotid artery stenting (CAS). CAS for vulnerable lesions has not been established; therefore, we gradually expand stents in such patients. This study aimed to compare the incidences of complications between gradual-expansion CAS for vulnerable lesions and standard CAS for non-vulnerable lesions. For gradual-expansion CAS, we used 3.0 or 4.0 mm balloons for minimal luminal diameters (MLDs) <2.0 or ≥2.0 mm, respectively, for pre-stenting angioplasty (SA) and did not overinflate them. By contrast, for standard CAS, we used a 4.0 mm balloon and overinflated it to 4.23 mm. A closed-cell stent was deployed, and post-SA was not performed in both groups. We evaluated the MLD before and minimal stent diameter (MSD) immediately after CAS, as well as periprocedural complications of combined stroke, death, and myocardial infarction within 30 days after CAS. In the vulnerable and non-vulnerable groups, 30 and 38 patients were analyzed, the MLDs were 0.76 and 0.96 mm before CAS, the MSDs were 2.97 mm and 3.58 mm after CAS, and the numbers of complications were 0 and 1, respectively. Gradual-expansion CAS for vulnerable lesions was as safe as standard CAS for non-vulnerable lesions.

Keywords: carotid artery stenting; intraplaque hemorrhage; periprocedural complications; post-stenting angioplasty; vulnerable lesion.

Figure 1

Flowchart of the patient selection process for the analysis. CAS, carotid artery stenting; CASr, carotid artery stenosis rate; DSA, digital subtraction angiography; ex-CS, extremely high-grade carotid stenosis; HF, heart failure; IPH, intraplaque hemorrhage; MLD, minimal luminal diameter; MRI, magnetic resonance imaging; US, ultrasonography.

Figure 2

T1-weighted black blood magnetic resonance imaging reveals a high signal intensity of 1533 in carotid lesions (arrows) and a signal intensity of 636 in the sternocleidomastoid muscle (arrowhead) in axial (A) and sagittal (B) images, indicating a relative signal intensity of 2.44.

Figure 3

Serial angiograms before (A), immediately after (C), and at four months after (D) carotid artery stenting (CAS) and the balloon (arrow) and filter (arrowhead) during inflation (B) in the same case as in Figure 2. The minimal luminal diameter is 0.26 mm (A: arrow). The semi-compliant balloon flexibly dilates the lesion along the artery (B: arrow). The minimal stent diameter is 2.69 mm after CAS (C: arrow), and the minimal stent diameter at four months is 3.97 mm (D: arrow). CAS, carotid artery stenting.

Figure 4

Pictures of the stent in the same case as in Figure 2. (A) The stent is stenotic immediately after carotid artery stenting. (B) The stent has expanded spontaneously at four months.

Figure 5

Serial changes in luminal diameters before, immediately after, and four months after CAS. The solid line shows changes in the diameters in the IPH group. The dotted line shows changes in the diameters in the non-IPH group. CAS, carotid artery stenting; IPH, intraplaque hemorrhage.