Reduction of postprocedure microemboli following retrospective quality assessment and practice improvement measures for carotid angioplasty and stenting

Objective: We have previously demonstrated a 70% incidence of microemboli on diffusion weighted magnetic resonance imaging (DW-MRI) following carotid angioplasty and stenting (CAS). The purpose of this study is to compare the incidence of microemboli in two distinct time periods when procedural modifications were implemented into a CAS program. Methods: Following a retrospective quality review of our CAS cohort (n = 27) from November 2004 through April 2006 (period 1), we enrolled patients (n = 20) from May 2006 through February 2008 (period 2) undergoing CAS into a prospective cohort that included obtaining pre- and postprocedure DW-MRI exams. Procedural modifications during period 2 included the preferential use of closed-cell systems (60% vs 0% in period 1), early heparinization at the initiation of arterial access, and elimination of an arch angiogram. The hospital records of these 47 patients were reviewed; symptoms, comorbidities, lesion characteristics, periprocedural information, and postoperative outcomes were collected. The incidence and location of acute, postprocedural microemboli were determined using DW-MRIs. Results: Twenty (74%) CAS patients from period 1 and seven (35%) patients from period 2 demonstrated acute microemboli on postprocedural DW-MRI (P = .02). The mean number of microemboli in period 1 was 4.1 ± 5.3 vs 1.5 ± 2.7 during period 2 (P = .04). Two of the 27 patients (7.4%) during period 1 experienced temporary neurologic changes that resolved within 36 hours. None of the patients during period 2 exhibited any neurologic changes. Patient demographics, comorbidities, and presenting symptoms were similar between the two groups except for smoking prevalence, female presence, and obesity (BMI > 30). Period 2 patients when compared with period 1 had more technically challenging anatomy with more calcified lesions (68% vs 27%), longer lesions (15.9 mm vs 8.2 mm), and higher incidence of ulceration (55% vs 27%) (all P < .04). Conclusion: Despite successful performance of 47 consecutive CAS procedures without permanent neurologic sequelae, significant reductions in periprocedural embolic events as identified via DW-MRI lesions may be achieved through implementation of quality improvement measures identified through continuous outcome analysis. The long-term neurologic benefits associated with reduced subclinical neurologic events remains to be determined.