Frequency of renal artery stenosis and variants of renal vascularization in hypertensive patients: analysis of 1550 angiographies in one centre

Multidetector computed tomography angiography study of the renal arterial vasculature anatomy and its variations in a Bulgarian adult population

PURPOSE

Renal arterial anatomy has a great clinical importance during surgical and endovascular procedures. However, comprehensive data on renal arterial variations in the Bulgarian population has not yet been provided. The aim of this study was to conduct a detailed research about the normal anatomy and variations of the renal arteries in the Bulgarian population.

METHODS

Five hundred sixty-one patients underwent contrast-enhanced multidetector computed tomography scans for the period 2016-2021. The images were retrospectively reviewed. Number, branching pattern, origin level and course of the renal arteries were noted. Data were categorized on the basis of laterality, gender and symmetry.

RESULTS

Only 46.3% of the patients exhibited normal renal arterial anatomy. Variations were observed in 301 patients (53.7%). The most common variant was the presence of accessory renal arteries (ARA), discovered in 41.2% of the subjects. There was no significant difference based on gender and laterality (p > 0.05). Hilar ARA (72.6%) were significantly more common than polar ARA (p < 0.001). The most common origin location of the main renal arteries and ARA was the aorta, followed by the common iliac arteries. Early division was observed in 21.7% of the patients, significantly more common on the right. Precaval course was found in 0.5% of the right main renal arteries and in 30% of ARA and the difference was significant (p < 0.001).

CONCLUSION

These results show novel insight into the prevalence of renal arterial variations in the Bulgarian population. Anatomic renal vasculature variants are common therefore awareness is crucial for the success of surgical and interventional procedures.

The preservation of accessory renal arteries should be considered the treatment of choice in complex endovascular aortic repair

OBJECTIVE

To evaluate renal function and renal parenchymal length changes secondary to the coverage or preservation of accessory renal arteries (ARA) in complex aortic repair.

METHODS

Single-center retrospective study identifying all patients undergoing fenestrated or branched endovascular aortic repair (f-b EVAR) who present ARA. Two groups were created, a preserved ARA group, with incorporation of the vessel as a dedicated fenestration or branch in the endograft plan, and a non-preserved ARA group, without incorporation of them. Early >30% decline of glomerular filtration rate (GFR), kidney infarcts and endoleaks (EL) were evaluated. Mid-term results with freedom from kidney shrinkage (defined as length decrease > 10%) at follow-up, freedom from GFR decrease >30% or need for postoperative dialysis at follow-up were also analyzed. Primary assisted patency of incorporated ARA was calculated.

RESULTS

From 2011-2020, 145 patients undergoing complex aortic repair presented with an ARA. After excluding ruptured aneurysms, 33 patients had the ARA preserved with their incorporation into the stentgraft (preserved ARA group), and 99 did not have preservation of them (not-preserved ARA group). There were no statistical differences in demographics or type of aneurysm. Patients in the ARA-preserved group had more ARA (median of 2 per patient vs 1 in the non-preserved ARA group, p 0,01) and bigger ARA (median 4 vs 3 mm in the non-preserved ARA group, p 0,001).Early postoperative worsening >30% of GFR (23 vs 6%, p 0,03) as well as postoperative renal infarction (57% vs 6%, p 0,001) and ARA-related EL (20 vs 0%, p 0,01) were statistically higher for the not-preserved ARA group.Mid-term kidney length showed significant shrinkage in the not-preserved ARA group compared to the ARA preserved group (9,7 vs 0%, p 0,001). Freedom from >30% GFR decline at 2 years was significantly higher for the preserved ARA group (83% vs 47%, p 0,01).Two-years primary assisted patency of incorporated ARA was 94%.

CONCLUSIONS

In complex aortic repair incorporation of ARA is feasible, with low complications and good primary assisted patency at 2 years. It leads to less postoperative early renal dysfunction as well as higher freedom for mid-term renal disfunction and kidney shrinkage.

Relationship between Accessory Renal Artery and Clinical Characteristics of Middle-Aged Patients with Primary Hypertension

Objectives

The association between accessory renal artery (ARA) and hypertension remains not fully understood. We observed the association between ARA and clinical characteristics among middle-aged patients with primary hypertension.

Methods

One hundred and sixty-two middle-aged (mean 39.82 ± 10.25 years, 58.0% male) patients with primary hypertension were enrolled, and patients underwent Computed Tomography Angiography (CTA) of renal arteries, ambulatory blood pressure monitor (ABPM), echocardiography, physical examination, and routine blood chemistry examinations. According to the CTA results, patients were divided into a non-ARA (n = 108) and ARA (n = 54) group. Direct renin concentration (DRC), plasma aldosterone concentration (PAC), ABPM, echocardiography, creatinine, and glomerular filtration rate were compared between the two groups.

Results

DRC (mU/L) (11.21 (5.34, 20.87) vs. 18.24 (10.32, 33.59), P=0.002) was significantly higher in the ARA group than in the non-ARA group. However, PAC (ng/dL) (98.30 (67.30, 134.00) vs. 116.50 (78.80, 137.25), P=0.103) was similar between these two groups. ABPM (mmHg) results showed that daytime (146.75 ± 17.04/95.86 ± 11.39 vs. 155.50 ± 14.76/100.48 ± 10.69, P < 0.05), night time (133.44 ± 17.50/85.28 ± 12.80 vs. 139.81 ± 14.64/89.83 ± 11.21, P < 0.05), and 24 h blood pressure (143.95 ± 15.99/93.90 ± 11.78 vs. 152.07 ± 13.85/98.11 ± 10.36, P < 0.05) were significantly higher in the ARA group than in the non-ARA group. Accordingly, echocardiographic-derived posterior left ventricular wall thickness value was higher in the ARA group than in the non-ARA group.

Conclusion

ARA is related to higher blood pressure and higher direct renin concentration in middle-aged patients with primary hypertension, and these patients deserve stricter blood pressure control. Our results provide important evidence for that ARA is a cause of hypertension and target organs damages.

Renin dependent hypertension caused by accessory renal arteries

Background

Hypokalemia in the presence of hypertension is often attributed to primary hyperaldosteronism as a cause of secondary hypertension, however secondary hyperaldosteronism may present similarly. Accessory renal arteries are variants in the vascular anatomy which are often thought to be innocuous but in some circumstances can cause renovascular hypertension leading to secondary hyperaldosteronism.

Case presentation

We report 2 cases of hypertension with secondary hyperaldosteronism associated with accessory renal arteries. Both patients presented with hypokalemia and further investigations revealed hyperaldosteronism with unsuppressed renin levels. Imaging studies showed the presence of accessory renal artery.

Conclusion

Accessory renal arteries are a potential cause renovascular hypertension which can be detected via CT angiography or magnetic resonance angiography. Hormonal evaluation should be undertaken to determine whether its presence contributes to hypertension in the patient as targeted treatment such as aldosterone antagonist can be initiated. Surgical intervention or renal denervation may be considered in resistant cases.

Coronary Tortuosity: A Clue to the Diagnosis of Fibromuscular Dysplasia?

BACKGROUND

Fibromuscular dysplasia (FMD) is a systemic, nonatherosclerotic, noninflammatory vasculopathy that is often overlooked by clinicians. Clinical clues could help in selecting patients for further evaluation for the presence of FMD. Recently, it was observed that tortuosity of the coronary arteries is often present in patients with FMD-related abnormalities of the coronary artery. Therefore, we wondered if the presence of coronary tortuosity might provide a clinical clue to the diagnosis of extracoronary FMD.

CASES

We describe 5 cases of FMD in whom diagnostic studies for FMD were initiated because of the presence of coronary tortuosity. FMD was found in all 5 patients in the renal and/or cervical arteries.

CONCLUSIONS

Our 5 cases suggest that exertional chest pain in the presence of coronary tortuosity may be helpful in selecting patients for further evaluation for the presence of FMD. Further research should focus on the prevalence of FMD among patients with coronary tortuosity and whether the presence of additional clinical clues (such as the presence of hypertension at young age or pulsatile tinnitus) next to coronary tortuosity can predict the risk for FMD in individual patients.

Atherosclerotic Renal Artery Stenosis Prevalence and Correlations in Acute Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Interventions: Data From Nonrandomized Single-Center Study (REN-ACS)—A Single Center, Prospective, Observational Study

Background

We are the first to evaluate the prevalence of renal artery stenosis (RAS) in consecutive patients with acute myocardial infarction (AMI) referred for primary percutaneous coronary intervention from a single tertiary center. As a novelty, we assessed hydration and metabolic status and measured arterial stiffness. We elaborated a predicting model for RAS in AMI.

Methods and Results

One hundred and eighty‐one patients with AMI underwent concomitantly primary percutaneous coronary intervention and renal angiography. We obtained data on demographics, medical history, cardiovascular risk factors, echocardiography, Killip class, and blood tests. In the first 24 hours post–primary percutaneous coronary intervention, we assessed bioimpedance through Body Composition Monitoring^® and arterial stiffness through pulsed‐wave velocity, SphygmoCor^®. Significant RAS (>50% lumen narrowing, RAS+) was present in 16.6% patients. In the RAS+ group we recorded significantly higher stiffness, CRUSADE score and dehydration, and more women with higher prevalence of multivascular coronary artery disease and heart failure. In our multivariate models, variables independently associated with RAS+ were previous percutaneous coronary intervention, low estimated glomerular filtration rate, multivascular coronary artery disease, and total/extracellular body water. These models had good specificity and low sensitivity.

Conclusions

We observed that RAS+ AMI patients have a particular hydration, metabolic, and endothelial profile that could generate more future major adverse cardiac events. Hence, renal angiography in AMI should be considered in specific subsets of patients.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02388139.

Update on intervention versus medical therapy for atherosclerotic renal artery stenosis

Atherosclerotic renal artery stenosis is known to be one of the most common causes of secondary hypertension, and early nonrandomized studies suggested that renal artery stenting (RASt) improved outcomes. The vascular community embraced this less invasive treatment alternative to surgery, and RASt increased in popularity during the late 1990s. However, recent randomized studies have failed to show a benefit regarding blood pressure or renal function when RASt was compared with best medical therapy, creating significant concerns about procedural efficacy. In the wake of these randomized trial results, hypertension and renal disease experts along with vascular interventional specialists now struggle with how to best manage atherosclerotic renal artery stenosis. This review objectively analyzes the current literature and highlights each trial's design weaknesses and strengths. We have provided our recommendations for contemporary treatment guidelines based on our interpretation of the available empirical data.

Smaller caliber renal arteries are a novel feature of uromodulin-associated kidney disease

Hyperuricemia is very common in industrialized countries and known to promote vascular smooth muscle cell proliferation. Juvenile hyperuricemia is a hallmark of uromodulin-associated kidney disease characterized by progressive interstitial renal fibrosis leading to end-stage renal disease within decades. Here we describe a member of a Polish-German family with a history of familial background of chronic kidney disease, hyperuricemia, and gout. This patient had hypertension because of bilateral small renal arteries, hyperuricemia, and chronic kidney disease. Clinical and molecular studies were subsequently performed in 39 family members, which included a physical examination, Duplex ultrasound of the kidneys, laboratory tests for renal function, and urine analysis. In eight family members contrast-enhanced renal artery imaging by computed tomography-angiography or magnetic resonance imaging was conducted and showed that bilateral non-arteriosclerotic small caliber renal arteries were associated with hyperuricemia and chronic kidney disease. Of the 26 family members who underwent genotyping, 11 possessed the P236R mutation (c.707C>G) of the uromodulin gene. All family members with a small caliber renal artery carried the uromodulin P236R mutation. Statistical analysis showed a strong correlation between reduced renal artery lumen and decreased estimated glomerular filtration rate. Thus, bilateral small caliber renal arteries are a new clinical phenotype associated with an uromodulin mutation.

Renal denervation for hypertension refractory to renal artery stenting

PURPOSE

To investigate the effect of renal denervation (RDN) on blood pressure and renal function in refractory hypertension after renal artery recanalization and optimal medical therapy.

METHODS

Ten patients (6 women; mean age 70.0±5.1 years) with an office systolic blood pressure >160 mmHg despite taking ≥3 antihypertensive drugs and uni- or bilateral renal artery stenting were treated with RDN. Radiofrequency (RF) energy was delivered to the native segment of the artery keeping a 5-mm safe distance from the stented segments. Standardized office (OBP) and ambulatory (ABP) blood pressure measurements, medication, and renal assessment, including renal duplex ultrasound and renal function, were determined at baseline and on follow-up to 12 months.

RESULTS

OBP (systolic/diastolic) at baseline was 190.0±20.4 / 84.2±10.1 mmHg. It decreased to 171.1±28.7* / 82.2±8.7, 165.5±28.4(†) / 76.1±7.4, and 158.3±14.2(†) / 75.5±9.5(†) mmHg (*p<0.001; (†)p<0.01) at 3, 6, and 12 months after RDN, respectively. Average ABP (systolic/diastolic) after 6 and 12 months decreased by -7.6(‡) / -3.1 and -11.3(‡) / -5.1(‡) mmHg ((‡)p<0.05). There was no renal artery (re)stenosis, dissection, or aneurysm within 12 months. Creatinine, cystatin C, and glomerular filtration rate remained unchanged. Urine albumin excretion decreased in 4/10 patients. Renal resistive indices improved in native, but not in stented renal arteries within the follow-up period.

CONCLUSION

This proof-of-concept study demonstrates that RF-based RDN can be safely and effectively delivered in patients with resistant hypertension and previous renal artery stenting.

Resistant hypertension in office practice: a clinical approach

Resistant hypertension is defined as blood pressure uncontrolled to guideline levels despite the use of ≥3 antihypertensive medications. When evaluating patients with resistant hypertension, it is important to consider issues such as blood pressure measurement technique, lifestyle, other comorbid conditions and medications, and the white coat effect. To this point, potential contributing factors include obstructive sleep apnea, excess alcohol intake, and use of blood pressure-elevating medications, such as nonsteroidal anti-inflammatory drugs, sympathomimetics, certain anorexic agents, and oral contraceptives. Secondary causes of hypertension are common in patients with resistant hypertension and appropriate screening tests should be performed as suggested by signs, symptoms, and laboratory abnormalities. In this regard, there is increasing evidence that hyperaldosteronism is common in the resistant hypertensive patient group. Pharmacologic therapy in patients with resistant hypertension is centered on drug combinations that have different mechanisms of action, including diuretics, which are essential in maximizing antihypertensive effects. The role of mineralocorticoid receptor antagonists is expanding, especially in patients with the metabolic syndrome, where aldosterone excess is increasingly recognized as an etiology of resistant hypertension. Finally, when appropriate, specialist referral may be necessary to appropriately assess and treat these patients.