The risks and benefits of renal artery stenting in fibromuscular dysplasia. lessons from arcadia-pol study

Objective: Percutaneous transluminal angioplasty (PTA) is the recommended revascularization strategy in patients with renal artery stenosis (RAS) caused by fibromuscular dysplasia (FMD), limiting stenting to complications management. However this recommendation is based on cases reports and small series. The main aim of the study was to retrospectively analyze immediate and long-term results of renal stenting and PTA in FMD patients. The second aim was to evaluate the results of stenting as support of renal artery aneurysm (RAA) closure. Design and method: The study group consisted of 58 patients percutaneously treated due to significant RAS (70 arteries) and 9 patients (10 RAAs) with a history of stent implantation before aneurysm embolization, derived from 343 ARCADIA-POL registry patients. PTA was performed as initial treatment in 61 arteries (PTA-group), whereas primary stenting was done in 9 arteries (STENT-group). Stent-related complications(SRC) were defined as: in-stent restenosis (>50%) or occlusion (ISR/O); stent fracture; stent underexpansion (SU) or migration. Results: In PTA-group, the first restenosis rate was 50.8%. Subsequently, 22 arteries underwent a second procedure: re-PTA(12 arteries) or stent implantation(10 arteries) . The incidence of recurrent restenosis after re-PTA was 41.7%. In the 10 arteries initially treated with PTA that underwent stenting for restenosis, complications occurred in 7 of them (70%), including 2 SUs and 5 ISR/Os . In STENT-group, SU occurred in one case (11.1%) and in-stent restenosis in 33.3% (3 of 9 stents). In combined analysis, SRC occurred following 11/19 stenting procedures (57.9%) including 3 periprocedural (SUs) and 8 late complications (ISR/Os). Finally, despite several subsequent revascularization attempts, 4 of 19 (21%) stented arteries were totally occluded and one remained significantly stenosed at follow-up imaging (Figure). In contrast to FMD-RAS procedures, there was only one intraprocedural complication (partial stent migration) and no late SRC in RAA patients. Conclusions: Renal artery stenting in FMD provides modest benefit in terms of restenosis prevention but poses high risk of immediate and late complications, including stent occlusion. Our study supports recommendations limiting stenting to the management of complications. In contrast, renal artery stenting in FMD RAA closure is associated with favorable long-term outcomes.