Issues related to renal artery angioplasty and stenting

Pickering syndrome in a patient with a single kidney: role of renal artery stenting

Renal artery stenosis (RAS) is associated with hypertension and high mortality rates. With its prevalence and associated risk of death, it is important to screen for patients displaying symptoms of RAS. RAS has a wide spectrum of clinical manifestations and is usually resistant to medical therapy. Of these clinical manifestations is Pickering syndrome which is characterized by bilateral renal arterial occlusion inflow lesions, flash pulmonary edema, acute kidney injury, and hypertensive emergencies in the setting of a preserved left ventricle function. Stenting techniques have been used extensively to treat symptomatic renal artery stenosis with excellent primary patency rate, however have failed to demonstrate a long-term benefit over the optimal medical management alone in randomized trials. However, accumulating evidence suggests that stenting is justified in specific patient subgroups that have severe occlusive renal artery stenoses with significant clinical sequelae, including flash pulmonary edema, acute ischemic kidney injury, and uncontrolled hypertension. In this report we discuss the case of a 32-year-old male who presented to our center with recurrent flash pulmonary edema and hypertensive emergency and was found to have RAS, which responded well to renal artery stenting. In conclusion, correcting the renal arterial inflow stenosis is beneficial and warranted in selective clinical scenarios.

The impact of renal artery stenting on therapeutic aims

Renal artery stenosis manifests as poorly-controlled hypertension, impaired renal function or pulmonary oedema, therefore the success of treatment is dependent on indication. This study aims to determine the outcomes of patients undergoing renal artery stenting (RASt) based on therapeutic aim compared to criteria used in the largest randomised trial. Retrospective case-note review of patients undergoing RASt between 2008-2021 (n = 74). The cohort was stratified by indication for intervention (renal dysfunction, hypertension, pulmonary oedema) and criteria employed in the CORAL trial, with outcomes and adverse consequences reported. Intervention for hypertension achieved significant reduction in systolic blood pressure and antihypertensive agents at 1 year (median 43 mmHg, 1 drug), without detrimental impact on renal function. Intervention for renal dysfunction reduced serum creatinine by a median 124 μmol/L, sustained after 6 months. Intervention for pulmonary oedema was universally successful with significant reduction in SBP and serum creatinine sustained at 1 year. Patients who would have been excluded from the CORAL trial achieved greater reduction in serum creatinine than patients meeting the inclusion criteria, with equivalent blood pressure reduction. There were 2 procedure-related mortalities and 5 procedural complications requiring further intervention. 5 patients had reduction in renal function following intervention and 7 failed to achieve the intended therapeutic benefit. Renal artery stenting is effective in treating the indication for which it has been performed. Previous trials may have underestimated the clinical benefits by analysis of a heterogenous population undergoing a procedure rather than considering the indication, and excluding patients who would maximally benefit.

Renal Arteriography via Radial Artery Access with a 125 cm Long Angiographic Catheter

A 125 cm long catheter makes it possible to perform renal arteriography via radial artery, but its feasibility and safety remain unclear. Our study recruited 1,323 patients grouped by two different vascular accesses to renal arteriography, i.e., femoral artery access and radial artery access. The success rate of angiography was 100% in both groups. Differential analysis showed that the overall complication incidence of radial artery access group was significantly lower (2.5% for radial artery access vs. 4.8% for femoral artery access, p = 0.03). From this study, we suggest that using the 125 cm angiographic catheter to perform renal arteriography via radial artery access is feasible and safe.

Color-coded summation images in the evaluation of renal artery stenosis before and after percutaneous transluminal angioplasty

BACKGROUND

Endovascular therapy is the gold standard in patients with hemodynamic relevant renal artery stenosis (RAS) resistant to medical therapy. The severity grading of the stenosis as well as the result assessment after endovascular approach is predominantly based on visible estimations of the anatomic appearance. We aim to investigate the application of color-coded DSA parameters to gain hemodynamic information during endovascular renal artery interventions and for the assessment of the procedures´ technical success.

METHODS

We retrospectively evaluated 32 patients who underwent endovascular renal artery revascularization and applied color-coded summation imaging on selected monochromatic DSA images. The differences in time to peak (dTTP) of contrast enhancement in predefined anatomical measuring points were analyzed. Furthermore, differences in systolic blood pressure values (SBP) and serum creatinine were obtained. The value of underlying diabetes mellitus as a predictor for clinical outcome was assessed. Correlation analysis between the patients´ gender as well as the presence of diabetes mellitus and dTTP was performed.

RESULTS

Endovascular revascularization resulted in statistically significant improvement in 4/7 regions of interest. Highly significant improvement of perfusion in terms of shortened TTP values could be found at the segmental artery level and in the intrastenotical segment (p < 0.001), significant improvement prestenotical and in the apical renal parenchyma (p < 0.05). In the other anatomic regions, differences revealed not to be significant. Differences between SBP and serum creatinine levels before and after the procedure were significant (p = 0.004 and 0.0004). Patients´ gender as well as the presence of diabetes mellitus did not reveal to be predictors for the clinical success of the procedure. Furthermore, diabetes and gender did not show relevant correlation with dTTP in the parenchymal measuring points.

CONCLUSIONS

The supplementary use of color-coding DSA and the data gained from parametric images may provide helpful information in the evaluation of the procedures´ technical success. The segmental artery might be a particularly suitable vascular territory for analyzing differences in blood flow characteristics. Further studies with larger cohorts are needed to further confirm the diagnostic value of this technique.

Hypertension Drug Therapy

Hypertension is still the number one global killer. No matter what causes are, lowering blood pressure can significantly reduce cardiovascular complications, cardiovascular death, and total death. Unfortunately, some hypertensive individuals simply do not know having hypertension. Some knew it but either not being treated or treated but blood pressure does not achieve goal. The reasons for inadequate control of blood pressure are many. One important reason is that we are not very familiar with antihypertensive agents and less attention has been paid to comorbidities, complications as well as the hypertension-modified target organ damage in patients with hypertension. The right antihypertensive drug was not given to the right hypertensive patients at right time. This reviewer studied comprehensively the literature, hopefully that the review will help improve antihypertensive drug selection and antihypertensive therapy.