Delayed endovascular revascularization of renal artery bridging stent occlusion after complex Endovascular aortic repair

Introduction Complex aortic endovascular procedures are the preferred treatment for thoracoabdominal aortic disease. One potential complication is target vessel instability (including stenosis and thrombosis), particularly in renal arteries targeted by branches. Materials and Methods This is a retrospective analysis of patients treated between October 2019 and November 2024 at a tertiary referral center and who experienced occlusion of one or both renal bridging stents. Technical success was defined as successful recanalization of the occluded renal bridging stent graft with restoration of flow into the renal and segmental renal artery branches. Clinical success was defined as the patient being free from dialysis and improvement in renal function in patients without dialysis. Results Eleven patients underwent renal artery endovascular recanalization for bridging stent graft thrombosis. None of the study patients were on dialysis preoperatively and they had either normal renal function or mild renal impairment. Six patients (54%) presented with either a contained aortic rupture or an aneurysm size >8 cm and were treated acute/subacute using an off-the-shelf stent graft, four patients (36%) received custom-made devices, one patient was treated with fenestrated cuff. The mean age was 68.7 ± 5 years, and nine patients (81%) were male. The main symptoms included anuria in nine patients (81%), nausea, diarrhea, and abdominal flank pain in ten patients (90%). All patients experienced delayed renal ischemia of more than 24 hours from diagnosis to treatment initiation, ranging from 24 to 96 hours, with a mean of 27.2 hours. The mean time from index operation to renal stent graft thrombosis was 10.4 months (range 2–48 months). Technical success was achieved in 85% of cases. Perioperative complications occurred in 18% of patients. Nine patients (81%) required dialysis after intervention; in 73% of these cases, dialysis was temporary, while three patients (27%) required permanent dialysis. The cause of renal stent graft occlusion could not be determined in 55% of patients. The median follow-up after recanalisation was 18.5 months (IQR, 0-33). Conclusion Renal bridging stent graft thrombosis is not infrequent, and treatment is challenging. It seems to be more frequent in the emergent setting when IFU violations may play a role. The use of inner branch configurations was also overrepresented in our series. Delayed renal stent graft recanalization is a relatively safe and prolonged occlusion time alone should not be the deciding factor in pursuing recanalization. Instead, we advocate for a more aggressive approach in cases of renal stent graft thrombosis particularly when signs of kidney perfusion remain.