Introduction: Bilateral renal artery occlusion is not a common finding in Takayasu arteritis. Renovascular hypertension, kidney failure and even flash pulmonary edema (FPE) can occur in these circumstances. The presence of renal collateral circulation can modulate the clinical aspect of this spectrum.

Methods: Between 2001 and 2018, 24 cases of FPE se-condary to bilateral renal artery stenosis were treated by renal artery stenting. We report a case of bilateral renal artery occlusion secondary to Takayasu arteritis, complicated by FPE. A 55-year-old female with a his-tory of Takayasu arteritis, right hypoplastic kidney se-condary to right renal artery occlusion, and a history of repeated left renal artery stenting for recurrent in-stent restenosis was referred to our institution for refractory arterial hypertension and FPE. At the time of admis-sion the blood pressure reached 260/120mmHg. The patient was oliguric, with acute kidney failure (serum creatinine level of 6.9mg/dl) and severe anemia (Hb 7.0g/dl). Azathioprine treatment was stopped a month previously due to hematologic toxicity.

Results: Blood transfusion was administered for the correction of anemia. A multidisciplinary team was gathered and salvage angiography was decided on, followed, if necessary, by renal-replacement therapy. The length of the left kidney reached 12 cm on ultra-sound examination. Renal artery angiography was performed and identified total in-stent occlusion. Im-portant left extra-renal collateral circulation was seen, mostly from lumbar, periureteral and superior capsular arteries. The occlusion was crossed with a 0.014” gui-dewire and repeatedly predilated, with the subsequent restoration of flow. A distal dissection flap was noticed. Two 5.0/18mm zotarolimus eluting stents were im-planted, covering both the renal ostium and the distal dissected area. During the next 24 hours, the patient became polyuric. Blood pressure normalized and im-posed the withdrawal of antihypertensive medication. A 50% drop in serum creatinine was recorded. Pulse methylprednisolone therapy was initiated in the Rhe-umatology department. The patient made a full and uneventful recovery. She was discharged home with a serum creatinine of 1.22mg/dl. A low-dose calcium channel blocker was administered for blood pressure control.

Conclusions: In rare cases, a rich collateral arterial network formed by lumbar arteries, adrenal branches, inferior mesenteric and periureteral vessels have been described and reported to maintain renal viability. This specific situation created a temporal bridge that preser-ved the kidney until antegrade flow was percutaneously restored. Approaching renal artery occlusion through angioplasty and drug-eluting stent deployment is a promising therapeutic option, but further studies are needed in order to improve the method The presented case is a reminder of the fact that renal artery occlusion is not synonymous to kidney loss. Arterial reconstruc-tive techniques can save parenchyma and significantly improve renal function.