Renal artery and parenchymal changes after renal denervation: assessment by magnetic resonance angiography

Abstract

Objectives: Relatively little is known about the incidence of long-term renal damage after renal denervation (RDN), a potential new treatment for hypertension. In this study the incidence of renal artery and parenchymal changes, assessed with contrast-enhanced magnetic resonance angiography (MRA) after RDN, is investigated.

Methods: This study is an initiative of ENCOReD, a collaboration of hypertension expert centres. Patients in whom an MRA was performed before and after RDN were included. Scans were evaluated by two independent, blinded radiologists. Primary outcome was the change in renal artery morphology and parenchyma.

Results: MRAs from 96 patients were analysed. Before RDN, 41 renal anomalies were observed, of which 29 mostly mild renal artery stenoses. After a median time of 366 days post RDN, MRA showed a new stenosis (25-49% lumen reduction) in two patients and progression of pre-existing lumen reduction in a single patient. No other renal changes were observed and renal function remained stable.

Conclusions: We observed new or progressed renal artery stenosis in three out of 96 patients, after a median time of 12 months post RDN (3.1%). Procedural angiographies showed that ablations were applied near the observed stenosis in only one of the three patients.

Key points: • The incidence of vascular changes 12 months post RDN was 3.1%. • No renal vascular or parenchymal changes other than stenoses were observed. • Ablations were applied near the stenosis in only one of three patients.

Keywords: Hypertension; Magnetic resonance angiography; Renal artery stenosis; Renal denervation; Vascular changes.

Fig. 1

Radiofrequency ablation point on the procedural angiography (red arrow, panel a) near the location where on the magnetic resonance angiography (MRA) post renal denervation (RDN) a new renal artery stenosis was observed (red arrow, panel b)