Venous Microtrauma Associated with Pharmaco-Mechanical Thrombectomy in A Porcine DVT Model

AngioJet Rheolytic Thrombectomy (ART) is a commonly used mechanical thrombectomy device marketed for treating peripheral arterial and venous thrombotic occlusions. ART allows both pulse and thrombectomy modes to fragment and remove intraluminal thrombus. However, prior reports of serious adverse events, including death in patients with pulmonary emboli, have led to FDA black-box warning. We aimed to evaluate the histomorphic impact of ART on acute deep venous thrombosis (DVT) in the infrarenal vena cava (IVC). Six adult Yorkshire pigs underwent general anesthesia, endotracheal intubation, and continuous hemodynamic monitoring. Bilateral external jugular veins and bilateral femoral veins were percutaneously cannulated. Acute DVT was formed in the infrarenal IVC by inducing stasis using proximal and distal occlusive balloons, and injection of 20 mL of 25% ethanol (Fig 1). All pigs then underwent therapeutic anticoagulation with intravenous heparin. Three pigs underwent treatment with an 8Fr AngioJet ZelanteDVT catheter using mechanical thrombectomy (MT) and aspiration of 250 mL of 0.9% normal saline (NS) over 30 minutes using an AngioJet Power Pulse Delivery console. Three additional pigs were treated with pharmaco-mechanical thrombectomy (PMT) with an initial pulsing with 250 mL 0.9% NS supplemented with 10 mL 50,000 IU Streptokinase, followed by a lysis for 30- minutes, and then 30 minutes of MT. In both groups, serial venograms of the thrombosed segments were performed every 10 minutes. At the conclusion of the procedures, all pigs were euthanized, retroperitoneal exploration was performed, and the iliocaval venous segments were resected en bloc for histomorphic analysis. All six pigs tolerated the procedure without intraoperative hemodynamic instability or procedural complications. Serial venograms demonstrated that AngioJet significantly decreased thrombus in all six pigs compared to baseline (64.7% ± 9.7% vs 16.1% ± 10.5%; P = .02). Retroperitoneal exploration demonstrated evidence of vena cava micro-perforations and retroperitoneal bleeding in all six pigs. Histopathologic assessment revealed higher incidence of venous wall intimal tears in segments treated with MT or PMT compared to untreated segments (19.3 ± 4.3 vs 6.3 ± 1.5; P = .046 and 16.7 ± 2.7 vs 6.3 ± 1.5; P = .028, respectively) (Fig 2). Fibrin content of residual intraluminal thrombus was lower following PMT compared to MT. We demonstrated that AngioJet effectively reduces DVT volume in a porcine IVC. However, we observed increased IVC microtrauma and retroperitoneal bleeding following PMT compared to MT. Further preclinical studies may be needed to investigate the safety, efficacy, and short- and long-term impact of venous microtrauma related to the use of AngioJet.