Serial quantitative magnetic resonance angiography followup of renal artery dimensions following treatment by four different renal denervation systems

Aims: Renal sympathetic denervation (RDN) is being studied as a therapeutic option for patients with therapy- resistant hypertension. It remains unclear if the procedure affects the renal arteries in such a way that luminal narrowing might occur at the mid to longer term. The aim of the present study was to assess renal artery integrity accurately at the medium to long term using recently validated quantitative magnetic resonance angiography software in patients treated with four different RDN devices.
Methods and results: In a prospective cohort of 27 patients referred for RDN, quantitative magnetic resonance angiography (MRA) was used to assess 52 vessels at baseline, six, and 12 months post treatment with one of four different devices. No renal artery stenosis was seen at six or 12 months. The average mean lumen area was 26.6±7.3 mm2 at baseline versus 25.0±7.1 mm2 and 25.0±6.1 mm2 at six and 12 months, respectively, resulting in a late loss of 1.6 mm2 at six months and 1.9 mm2 at 12 months. No differences were observed in the arterial response to RDN with the four different systems used. There was no correlation between post-procedural dissections, oedema or thrombi as detected with invasive imaging, and luminal narrowing at follow-up.
Conclusions: Quantitative MRA of patients treated with RDN revealed no significant change in renal artery dimensions up to 12-month follow-up. The lack of a change in renal artery luminal dimensions was irrespective of the arterial response to the individual devices used.