Successful single-sided renal denervation approach in a patient with stenosis of an accessory renal artery

Catheter-based renal sympathetic nerve denervation on hypertension management outcomes

BACKGROUND

Renal sympathetic denervation (RSD) provides a minimally invasive interventional treatment modality for patients with resistant hypertension. However, the post-operative outcomes remain a key area of investigation since its earliest clinical trials.

AIM

To evaluate patient outcomes after RSD intervention among peer-reviewed patient cases.

METHODS

A systematic review of literature on MEDLINE, Google Scholar, and the Cochrane Database of Systematic Reviews for RSD case studies to assess post-operative hypertension readings and medical management.

RESULTS

Among 51 RSD cases, the post-operative RSD patients report an apparent reduction with a mean number of 3.1 antihypertensive medications. The mean systolic arterial blood pressure 1 year following RSD was 136.0 mmHg (95%CI: 118.7-153.3).

CONCLUSION

The apparent improvements in office systolic blood pressure after 12 month post-operative RSD can support the therapeutic potential of this intervention for blood pressure reduction. Additional studies which utilized a uniform methodology for blood pressure measurement can further support the findings of this systematic review.

Renal denervation in treatment-resistant hypertension: the need for restraint and more and better evidence

The Symplicity studies suggest that intravascular renal sympathetic nervous denervation improves blood pressure in patients with resistant hypertension, thus potentially opening a market for devices to be used when conventional drug therapy fails to restore blood pressure control. However, the size and durability of the antihypertensive, renal and sympatholytic effects of renal denervation, the long-term safety, improvement of quality of life, the possibility to relax antihypertensive drug treatment, the cost-effectiveness, and long-term hard cardiovascular-renal outcomes still remain to be firmly established. Most ongoing studies are small, industry-driven and purely observational with objectives to test new catheters and source of energy for renal nerve ablation or to search for ancillary benefits and new indications of the technique. The most urgent need, that is adequately powered randomized clinical trials testing renal denervation versus usual medical therapy delivered according to the state-of-the-art are under-represented and seldom funded by industry. The authors make a plea for a coordinated research effort in Europe. With this objective, they established collaboration with leading European experts and started the European Network for Coordinating Research on Renal Denervation. In the meantime, renal denervation should remain the ultima ratio in adherent and truly resistant patients with severe hypertension, confirmed by ambulatory monitoring, in whom secondary hypertension has been excluded and in whom all other efforts to reduce blood pressure have failed.

Catheter-based radiofrequency renal sympathetic denervation for resistant hypertension

PURPOSE

To evaluate the feasibility, efficacy, and safety of catheter-based radiofrequency renal sympathetic denervation for treatment of resistant hypertension.

MATERIALS AND METHODS

Twenty-four patients with essential hypertension unresponsive to at least three antihypertensive agents underwent renal denervation (RDN). Three patients had variant renal anatomy. Comorbidities included diabetes (n = 11), renal failure (n = 4), and obstructive sleep apnea (n = 2). The effect on 24-hour ambulatory blood pressure (BP) was assessed at 6 months. Patients with a decrease in systolic BP of at least 10mm Hg were considered responders.

RESULTS

RDN was bilateral in 19 patients and single-sided in five. The 19 patients with bilateral RDN showed mean reductions in 24-hour ambulatory BP of 20.7/8.7mm Hg±18.1/9.9 (systolic/diastolic; P = .0001/P = .0012). Sixteen bilaterally treated patients (84.2%) showed a systolic BP reduction of at least 10mm Hg and were considered responders, whereas only one of the five patients with single-sided RDN showed a response. Two responders with sleep apnea showed improvement in polysomnography indices, and one with left concentric ventricular hypertrophy showed complete cardiac remodeling 11 months after the RDN procedure. Renal function remained unchanged in all patients, including those with renal failure. Optical coherence tomography of the renal arteries in one patient showed sporadic endothelial scarring. Renal angiograms at 9 months (one patient) and 12 months (two patients) had normal findings.

CONCLUSIONS

Catheter-based RDN was carried out safely, even in patients with comorbidities, abnormal renal arteries, or anatomic variants. The response rate for bilateral RDN (84.2%) was comparable to previous reports.

Comparison of diagnostic accuracy of Doppler USG and contrast-enhanced magnetic resonance angiography and selective renal arteriography in patients with atherosclerotic renal artery stenosis

Background

There are many systemic complications of conventional selective renal arteriography (SRA), such as contrast-mediated nephropathy. Contrast-enhanced magnetic resonance angiography (CE-MRA) and renal artery Doppler ultrasonography (DUSG) have been used increasingly for renal artery stenosis (RAS). The aim of this study was to evaluate the accuracy of CE-MRA and DUSG as used for diagnosis of RAS.

Material/Methods

We divided 130 consecutive patients investigated for resistant hypertension into 2 groups based on age: group 1 was patients <60 years old and group 2 was patients >60 year. DUSG, CE-MRA, and SRA were performed in group 1 and group 2 patients.

Results

Seventy-two patients (24 males [M], 48 females [F]) in group 1, and 58 patients (26 M, 32 F) in group 2 were included in the study. In the evaluation of clinically significant renal artery stenosis with DUSG, in group 1 the overall sensitivity was 83.33% and overall specificity was 81.82%, and in group 2 they were 69.23% and 0%, respectively, when compared with SRA. In the evaluation of clinically significant renal artery stenosis with CE-MRA, the overall sensitivity and specificity were 92.31% and 36.36%, respectively, in group 1 and 100.00% and 73.33%, respectively in group 2, when compared with SRA.

Conclusions

CE-MRA is an accurate, non-invasive method for the diagnosis of RAS in patients above 60 years of age and DUSG may be the choice of diagnostic method for RAS in patients under 60 years of age.