RESUMO
BACKGROUND: Renal insufficiency and allergy to iodine contrast are relative contraindications to carotid artery stenting (CAS). The primary aim of this pilot study was to evaluate the feasibility and safety of the CAS assisted by 3D fusion of previously performed computed tomography (CTA) and magnetic resonance angiography (MRA) images and DynaCT, the secondary aim was to determine if 3D fusion decreases radiation exposure and the amount of contrast needed during the procedure. METHODS: Retrospective review of patients who underwent CAS between October 1st, 2012 and November 30th, 2014 was performed. CTA-assisted fusion was used in group A (CAS/CTA), MRA-assisted fusion in group B (CAS/MRA) and group C (control group) underwent CAS without fusion. No patient in the study had renal dysfunction, risk factors of contrast-induced nephropathy or insulin-dependent diabetes. Primary outcome was perioperative stroke or death, secondary outcome included technical success, radiation dose, exposure time and volume of contrast used. Statistical analysis was performed with Student's t-test, using the permutation methods. Level of significance was set at P<0.05. RESULTS: Fifty-seven patients (32 female, mean age: 69.4 years, range 61 to 82 years), underwent CAS (group A: 10 patients, group B: 10 patients, group C: 37 patients). Technical success was 100%. There was no 30-day mortality or stroke and there were no general, neurological or local complications. Mean contrast volume was significantly less in groups A and B, than in group C (15±5 mL and 16±4 mL vs. 51±16 mL, group A vs. C: t(43.35)=11.85; P<0.0001; group B vs. C: t(44.94)=12.23; P<0.00001). Radiation exposure time and dose were not statistically different between groups (group A vs. C: t(45)=0.95, P=0.3497 and t(45)=0.3, P=0.7694, respectively; group B vs. C: t(45)=0.93, P=0.3455 and t(45)=0.92, P=0.3644, respectively). CONCLUSIONS: Carotid stenting with 3D fusion in this pilot study was safe and feasible. 3D fusion techniques using either CTA or MRA allowed a significant reduction of contrast volume but did not reduce radiation dose or exposure time. Larger prospective studies of CAS with 3D fusion imaging in patients with renal insufficiency or mild allergy to contrast are warranted.