The periprocedural and 30-day outcomes of carotid stenting in patients with carotid artery near-occlusion

The safety of endovascular revascularization in patients with carotid artery near occlusion (CANO) is unknown. We aimed to evaluate the peri-procedural risk in CANO patients receiving carotid artery stenting (CAS). A prospective data base with retrospective review was performed to identify patients who underwent CAS with CANO from July 2006 to July 2020, and had at least 1-month clinical follow-up data. The primary endpoints were stroke, hyperperfusion syndrome, and death within 30 days after CAS. A total of 198 patients with carotid artery stenosis were enrolled including 92 patients with CANO and 106 age and sex-matched patients with 70–99% conventional carotid stenosis. Full distal carotid collapse was found in 45 CANO patients (45/92, 49%). The technical success rate was 100%. The CANO patients had significantly longer lesion lengths compared with those of the non-CANO group. The incidence of hyperperfusion syndrome was comparable (CANO: 2.2%, non-CANO: 0.9%, P = 0.598). The risks of ischemic stroke and death within 30 days were 1.1% and 0% in the CANO group; and 1.9% and 0.9%, in the non-CANO group, respectively, without statistical difference. In conclusion, CAS is safe for patients with CANO, with a similar low 30-day peri-procedural event rate comparable to those of non-CANO.

Long-term consequences of trans-radial catheterization on the radial artery

Background: The radial artery (RA) is often utilized for diagnostic coronary angiography and percutaneous intervention. Recent high-level evidence supports RA use in preference to saphenous vein as a conduit for coronary revascularization. Aim: To demonstrate gross and histologic changes of the RA following transradial access. Methods: We present two patients who had open RA harvest for coronary bypass surgery after transradial catheterization. Results: Examination 8 years after transradial catheterization demonstrated thickened intima and dissection, and examination 12 years following transradial catheterization with percutaneous coronary intervention demonstrated chronic dissection with thickened intima and near occlusion of the lumen. Conclusion: Transradial access via the RA, even after several years, is associated significant injury, making it unusable as a conduit for surgical coronary revascularization. A RA that has been utilized for catheterization should not be considered for coronary revascularization.

Near-Occlusion is a Common Variant of Carotid Stenosis: Study and Systematic Review

ABSTRACT: Background: Symptomatic carotid near-occlusion is often described as rare. Recent studies have shown that near-occlusions are overlooked, especially near-occlusion without full collapse (with a small but normal-appearing distal internal carotid artery). Objective: To assess the prevalence of near-occlusion among symptomatic ≥50% carotid stenosis, incidence of symptomatic near-occlusion, and review the literature. Methods: Prospective controlled single-center cross-sectional study. Consecutive cases with symptomatic ≥50% carotid stenosis were examined with computed tomography angiography (CTA). The CTAs were assessed for near-occlusion by two observers. A systematic literature review was performed with emphasis on how study design affects prevalence estimate. Results: Totally, 186 patients with symptomatic ≥50% carotid stenosis were included, 34% (n = 63, 95% CI 27, 41) had near-occlusion. The incidence of symptomatic near-occlusion was 3.4 (95% CI 2.5, 4.2) per 100,000 person-years. Inter-rater κ was 0.71. The average prevalence of near-occlusion among symptomatic ≥50% carotid stenosis was higher in studies with good design (30%, range 27%–34%) than studies without good design (9%, range 2%–10%). Conclusions: Near-occlusion is common variant of symptomatic ≥50% carotid stenosis, both in the current study and in all previous studies of good design. Studies that suggest that near-occlusion is rare have had methodological issues.

Defining carotid near-occlusion with full collapse: a pooled analysis

Purpose Create a new definition of near-occlusion with full collapse to predicting recurrent stroke. Methods Pooled analysis of two studies. Patients with symptomatic ≥ 50% carotid stenoses were included. Outcome was preoperative recurrent ipsilateral ischemic stroke or retinal artery occlusion within 28 days of presenting event. We analyzed several artery diameters on computed tomography angiography and stenosis velocity on ultrasound. Results A total of 430 patients with symptomatic ≥ 50% carotid stenosis were included, 27% had near-occlusion. By traditional definition, 27% with full collapse and 11% without full collapse reached the outcome (p = 0.047). Distal internal carotid artery (ICA) diameter, ICA ratio, and ICA-to-external carotid artery ratio were associated with the outcome. Best new definition of full collapse was distal ICA diameter ≤ 2.0 mm and/or ICA ratio ≤ 0.42. With this new definition, 36% with full collapse and 4% without full collapse reached the outcome (p < 0.001). Conclusions Defining near-occlusion with full collapse as distal ICA diameter ≤ 2.0 mm and/or ICA ratio ≤ 0.42 seems to yield better prognostic discrimination than the traditional appearance-based definition. This novel definition can be used in prognostic and treatment studies of near-occlusion with full collapse.

Near-occlusion is difficult to diagnose with common carotid ultrasound methods

Purpose To assess the sensitivity and specificity of common carotid ultrasound method for carotid near-occlusion diagnosis. Methods Five hundred forty-eight patients examined with both ultrasound and CTA within 30 days of each other were analyzed. CTA graded by near-occlusion experts was used as reference standard. Low flow velocity, unusual findings, and commonly used flow velocity parameters were analyzed. Results One hundred three near-occlusions, 272 conventional ≥50% stenosis, 162 <50% stenosis, and 11 occlusions were included. Carotid ultrasound was 22% (95%CI 14–30%; 23/103) sensitive and 99% (95%CI 99–100%; 442/445) specific for near-occlusion diagnosis. Near-occlusions overlooked on ultrasound were found misdiagnosed as occlusions (n = 13, 13%), conventional ≥50% stenosis (n = 65, 63%) and < 50% stenosis (n = 2, 2%). No velocity parameter or combination of parameters could identify the 65 near-occlusions mistaken for conventional ≥50% stenoses with >75% sensitivity and specificity. Conclusion Near-occlusion is difficult to diagnose with commonly used carotid ultrasound methods. Improved carotid ultrasound methods are needed if ultrasound is to retain its position as sole preoperative modality.