Endovascular management of acute postprocedural flow diverting stent thrombosis

Postprocedural thrombosis is a rare complication after flow diverting stent (FD) implantation for aneurysm treatment with few reported cases in the literature. Management strategies and outcomes associated with this complication have not been reported.

A multicenter retrospective series of cases of acute postprocedural FD thrombosis were compiled and prevalence was calculated based on procedural volumes over a 7 year period. Acute postprocedural FD thrombosis was defined as the development of neurologic deficit with angiographic imaging demonstrating acute thrombus within the index FD stent at least 2 hours following completion of the implantation procedure.

A total of 10 cases of postprocedural thrombosis were identified at five participating centers among a total of 768 patients treated (prevalence 1.3%). Thrombosis occurred a median of 5.5 days after implantation (range 0-83 days). 9/10 patients underwent emergent angiography with intent to perform endovascular reperfusion. A variety of different endovascular treatments were used, including aspiration thrombectomy, retrievable stent thrombectomy, balloon angioplasty, and intra-arterial thrombolytic infusion, without any procedural complications. There were no instances of FD migration, stent kinking, or aneurysm rupture. 90% of patients achieved Thrombolysis in Cerebral Infarction 2B or greater revascularization. Favorable clinical outcomes (modified Rankin Scale score of 0-2) at 3 months were achieved in 88% of patients.

Acute postprocedural thrombosis of an FD is a rare complication that occurs in approximately 1-2% of patients after aneurysm treatment. Patients presenting with acute postprocedural FD thrombosis should be aggressively managed using large vessel occlusion thrombectomy techniques, as good angiographic and clinical outcomes are possible.