Purpose: To investigate distal embolism during endovascular procedures of the infra-aortic arteries by utilizing a commercial filter basket and unveil any correlation between the baseline clinical and procedural variables and the histopathological findings of the collected particles.
Methods: In a prospective study, 48 patients (37 men; mean age 70.8+/-7.8 years, range 50- 83) underwent endoluminal therapy of infra-aortic lesions (stenosis >75% or occlusion; mean lesion length 52.2+/-38.0 mm) with standard endovascular procedures. A nitinol filter basket (n=50) was employed for distal protection. The collected particles were histopathologically analyzed. The harvested specimens were quantified after digital image post processing.
Results: Procedural success of filter-protected revascularization was 93.8%. Three failures included 1 vasospasm, 1 distal embolus, and 1 side-branch occlusion. The total area of retrieved particles per basket was 2.76+/-6.49 mm(2) (range 0.0-40.3). Particles with a major axis >1 and >3 mm were detected in 29 (58.0%) and 6 (12.0%), respectively, of the examined filters. Collected particles consisted primarily of platelets and fibrin conglomerates, trapped erythrocytes, inflammatory cells, and extracellular matrix. Increased lesion length, increased reference vessel diameter, acute thromboses, and total occlusions were positively correlated with higher amounts of captured particles (p<0.05). Multivariate analysis incriminated declotting procedures as the only independent predictor of increased embolic burden (p<0.05).
Conclusion: The embolism phenomenon during infra-aortic interventions is frequent and underestimated. The liberated particles consisted primarily of atheromatous plaque elements and thrombus. The reported data might support the application of a protective filter basket in selected subsets of lesions with a riskier embolic profile and whenever declotting procedures are performed.