Carotid Angioplasty and Stenting in Anatomically High Risk Patients: Safe and Durable, Except for Radiation-induced Stenosis

Background: Carotid endarterectomy (CEA) has been the gold standard for carotid artery stenosis in patients with good operative risk. Carotid angioplasty and stenting (CAS) is used in patients considered high risk for CEA. Patients may qualify as high-risk because of medical comorbid conditions or for anatomic considerations (previous ipsilateral CEA, history of radical neck dissection and/or radiation). We compared the technical feasibility and the success and durability of CAS in medically high risk patients (MED) versus anatomically high risk patients (ANAT).
Methods: A retrospective chart review was performed of all consecutive patients undergoing CAS by a single vascular surgery group. All patients were considered high risk and were evaluated with duplex ultrasound and angiography. Primary endpoints were technical success, 30-day stroke (CVA), myocardial infarction (MI) and death and in-stent restenosis > 50%. Statistical analysis was performed using Student’s t test, Fisher’s exact test, Chi square, Kaplan-Meier life table and Log-rank test.
Results: From January 2003 to December 2007, 230 CAS (ANAT=98, MED=132) were attempted. The ANAT cohort consisted of 86 patients with a single anatomic risk factor (73 patients with a previous ipsilateral CEA, 6 patients with high lesions, 6 with a history of neck radiation and 1 patient with a tracheostomy) and 12 patients with 2 or 3 anatomic risk factors (10 patients with a history of a radical neck dissection and radiation and 2 patients with a history of neck radiation and an ipsilateral CEA). Twenty-seven of the ANAT cohort also met criteria as medically high risk. The ANAT cohort (mean age of 71.1 years) was significantly younger than the MED cohort (mean age of 73.9 years) (p=0.021). The technical success rate was similar in the 2 cohorts (ANAT=96/98 (98.0%), MED=130/132 (98.5%) (p=0.76)). Mean follow-up was significantly longer in the anatomically high risk patients (ANAT=21.5 months, MED=10.5 months, p<0.0001). Thirty-day CVA and mortality rates were similar between the 2 cohorts (CVA: ANAT=1/98 (1.0%), MED=1/132 (0.8%), p=0.83; Death: ANAT=2/98 (2.0%), MED=1/132 (0.8%), p=0.79). There were 12 cases of restenosis, ANAT=7/96 (7.3%), MED=5/130 (3.8%) (p=0.36). However, there was no statistical difference in the Kaplan-Meier survival free of restenosis at 1 year (MED=91.9%, ANAT=95.2%) and at 2 years (MED=91.9, ANAT=91.0%) (p=0.98). Four of the 7 cases of restenosis occurred in patients with previous neck radiation. The restenosis rate for radiation-induced stenosis treated with CAS was significantly higher at 22.2% (4/18) when compared to 3.8% (3/78) for all other CAS performed in the ANAT group (p=0.028).
Conclusion: CAS is as technically feasible and durable in anatomically high risk patients as in medically high risk patients with similar rates of periprocedural stroke and death and late restenosis. However, patients with radiation-induced stenosis appear to be at an increased risk for restenosis after CAS.