Abbreviated Duplex Ultrasound Surveillance in TCAR May Be Safe and Cost-Effective

Carotid duplex ultrasound (CDUS) surveillance after carotid artery stenting has become controversial, with recent literature finding low rates of restenosis after carotid artery stenting and rising concerns over the high cost of surveillance. The objective of this study is to evaluate the use of CDUS surveillance after transcarotid revascularization (TCAR) and report long-term outcomes. This retrospective review investigated patients who had undergone TCAR at our institution. Patient demographics, comorbidities, indications, and lesion characteristics were recorded. Patient outcomes include incidence of in-stent restenosis (ISR) and neurologic events. ISR >50% was defined as peak systolic velocity >220 cm/s and internal carotid artery/common carotid artery ratio > 2.7, whereas >80% was defined as peak systolic velocity >340 cm/s and internal carotid artery/common carotid artery ratio >4.15. A Kaplan-Meier survival analysis on ISR was conducted. A total of 109 TCAR stents were deployed in 105 patients. Four patients were lost to follow-up. Study demographics are reported in Table I. Preoperatively, 62% of patients presented with >80% stenosis of the carotid. Over a third of patients were symptomatic. No intraprocedural complications were noted. Of the 101 patients not lost to follow-up, all had unremarkable 30-day postoperative CDUS examination. Of the 109 stents, 8 (7.4%) were found to have ISR >50%, with 3 of 8 progressing to >80% ISR. One patient was reintervened with repeat TCAR. The mean follow-up time was 18.17 months. No patients suffered from transient ischemic attacks or strokes (Table II). Table III details the characteristics of patients experiencing ISR. These patients had low rates of post-dilation balloon use, longer average lesion lengths, and had predominantly type C lesions. The Kaplan-Meier analysis found rates of freedom from >50% ISR at 6, 12, 24, 36, and 48 months to be 98.1%, 96.8%, 91.1%, 91.1%, and 65%, respectively (Fig 1). The rates of freedom from >80% ISR in this interval were 100%, 100%, 96.1%, 96.1%, and 82.4%, respectively (Fig 2). With low rates of ISR, transient ischemic attack, strokes, and reintervention, our experience recommends against traditional surveillance regimens with CDUS examination after TCAR. This study suggests that a normal 30-day postoperative CDUS examination followed by routine clinic follow-up may be sufficient in most patients. An additional 147 CDUS examinations were conducted costing $115,542 (national average cost of $786) to identify eight restenosis events with only one reintervention. Traditional CDUS surveillance should be reserved for patients with type C lesions, indication outside instructions for use (IFU) for TCAR, and high-grade contralateral stenosis or occlusion.Fig 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)Table IStudy population demographics, comorbidities, symptom status, and indicationsVariableNo.%Age, years71.9Sex (male)6864.76Patients symptomatic3834.86Current smoker2725.71Prior smoker5653.33Never smoked2624.76Uncontrolled hypertension3129.52Hyperlipidemia4340.95Diabetes4441.90Coronary artery disease4643.81COPD2624.76Prior CEA1514.29Prior CAS65.71High-risk CEA reason Medical3027.52 Anatomic3633.03 Anatomic and medical2926.61CAS, Carotid artery stenting; CEA, carotid endarterectomy; COPD, chronic obstructive pulmonary disease. Open table in a new tab Table IIStudy outcomes with regard to in-stent restenosis and neurological outcomesVariableNo.%Mean follow-up time18.17In-stent restenosis <50% to >50%87.39 From >50% to >80%342.85Neurological outcomes Total TIA00 Total strokes00 Patient mortality109.2 Mortality due to TCAR00TCAR, Transcarotid artery revascularization; TIA, transient ischemic attack. Open table in a new tab Table IIICharacteristics of patients experiencing restenosis after TCARGroup<50% to >50%>50% to >80%No.53Symptomatic stenosis10Currently smoking30Average lesion length, mm30.823.67Type of plaque Type A20 Type B10 Type C23Post dilation balloon use01Stent redone01TCAR, Transcarotid artery revascularization. Open table in a new tab