Incidence of Arterial Micro-embolization During Percutaneous AngioJet Thrombectomy of Hemodialysis Grafts

This study was designed to investigate the incidence of arterial embolization using a peripheral protection filter device in a series of patients undergoing percutaneous mechanical thrombectomy for the management of thrombosed hemodialysis arteriovenous grafts (AVGs). This prospective, single-center study included all eligible patients presenting during an 18-month period to undergo AVG percutaneous thrombectomy. Inclusion criteria was a recently thrombosed AVG with 2 cm of artery before the next arterial branching. Primary endpoint was the incidence of distal arterial macro- and micro-embolization determined by both digital subtraction angiography and histopathological analysis of the material collected. Secondary endpoints included quantitative measurements of the specimens using a 0+ (no material) to 3+ (maximum load) score. In total, 42 patients met the study's inclusion criteria. No procedure-related complications or angiographically evident arterial embolization were noted. Macroscopically evident material was present in 47.6 % (20/42 filters). Histopathology demonstrated that the embolic material was primary consisted of fibrin conglomerates and platelets (median score: 1.5, confidence interval: 1.0-3.0), whereas inflammatory cells, trapped erythrocytes, extracellular matrix, cholesterol clefts, foam cells, necrotic core, and smooth muscle cells also were detected. Mean total area of embolic material was 5.04 mm(2) (range 0.05-5.21). The mean major axis of the largest particle was 1.83 mm (range 0.29-6.64), whereas 19 % (8/42) contained particles with major axis > 1 mm and 12 % (5/42) with major axis > 3 mm. In this study, the percentage of arterial micro-embolization was significantly higher than previously reported. However, the detrimental, long-term, clinical relevance remains to be determined.