Correlation between Renal Artery Anatomy and Hypertension: A Retrospective Analysis of 3000 Patients

The accessory renal arteries: A systematic review with meta-analysis

The accessory renal arteries (ARAs) are a well-described variant of the renal vasculature with clinical implications for radiologists, surgeons, and clinicians. The aim of the present systematic review with meta-analysis was to estimate the pooled prevalence of ARAs, including their variant number, origin, and termination, and to highlight symmetrical and asymmetrical morphological patterns. The systematic review used four online databases in accordance with PRISMA 2020 and Evidence-based Anatomy Workgroup guidelines. R programming software was used for the statistical meta-analysis. A total of 111 studies were considered eligible for our initial aim. The typical renal artery (RA) anatomy (a single bilateral vessel) was identified in 78.92%; the overall ARA prevalence was estimated at a pooled prevalence of 21.10%. The estimated pooled prevalence of one, two, three, and four ARAs were 18.67%, 1.80%, 0.01%, and <0.01%. The ARAs have been the subject of extensive research owing to their clinical importance, including in kidney transplantation surgery and resistant hypertension therapy. Knowledge of the typical and variant anatomy of RAs is essential for anatomists, radiologists, surgeons, and clinicians in order to avoid misunderstanding, complications, and iatrogenic injury.

Multiple Treatment Strategies of Accessory Renal Artery Related Hypertension: Report of Two Cases and Literature Review

Renovascular hypertension (RVH) is a primary cause of secondary hypertension, primarily driven by the activation of the renin-angiotensin-aldosterone system activation. Recently, growing studies suggested accessory renal artery (ARA) might also contribute to RVH. However, the treatment of ARA-related hypertension and whether to take interventional treatment lack consensus. Herein, we report two cases of ARA-related hypertension in our hospital. Imaging studies of both patients showed ARA stenosis. One patient had ARA occlusion well-compensated through tortuous collateral branches, achieving normal blood pressure by medical treatment alone. The other patient had ARA stenosis coexisted with main renal artery stenosis, and revascularization of both arteries led to a significant postoperative reduction in blood pressure. A literature review was conducted to summarize overall treatment strategies for ARA-related hypertension and clarify the relationship between ARA and hypertension. Recent research supported an association between ARA and hypertension. While medical therapy remains the first-line treatment for ARA-related hypertension, interventional procedures should be considered for patients whose blood pressure remains uncontrolled despite conservative management.

Aspects of renal function and renal artery anatomy as indications for renal denervation

Renal denervation (RDN) is a minimally invasive, endovascular catheter-based procedure using radiofrequency, ultrasound, or alcohol-mediated ablation to treat resistant hypertension. As more attention is focused on the renal sympathetic nerve as a cause and treatment target of hypertension, understanding the anatomy of the renal artery may have important implications for determining endovascular treatment strategies as well as for future selection of devices and appropriate candidates for RDN treatment. However, the anatomical structure of the renal artery (RA) is complex, and standardized morphological evaluations of the RA structure are lacking. Computed tomography angiography or magnetic resonance angiography imaging is useful for assessing RA anatomy before conducting RDN. RA echocardiography is an established noninvasive screening method for significant stenosis. Major randomized controlled trials have limited enrollment to patients with preserved renal function, usually defined as an estimated glomerular filtration rate (eGFR) ≥ 45 mL/min/1.73 m2. Therefore, the level of renal function at which RDN is indicated has not yet been determined. This mini-review summarizes the characteristics of renal artery anatomy and renal function that constitute indications for renal denervation. (Role of Clinical Trials: K. Kario is an Executive Committee Principal Investigator for the Spyral OFF MED, the Spyral ON MED, the DUO and the REQUIRE; a Coordinating investigator for the TCD-16164 study; a Site Principal Investigator for the HTN-J, the Spyral OFF MED, the Spyral ON MED, the DUO, the REQUIRE and the TCD-16164 study). Evaluation of renal arteries for radiofrequency renal denervation. A Simultaneous quadrantal ablations at four sites in the main renal artery or the equivalent renal artery to the main renal artery. B If there is a renal artery branch with a diameter >3 mm in the middle of the main renal artery, this branch is the distal end of the main renal artery. In this case, four simultaneous and quadrantal ablations can be performed on the equivalent renal arteries. C Four simultaneous and quadrantal ablations can be performed in the branch renal artery. D Sonication should be spaced at least 5 mm (one transducer*) apart. Perform 2 to 3 mm proximal to the arterial bifurcation. Perform 2 to 3 mm distal to the abdominal aortic inlet.

Effect of Accessory Renal Arteries on Essential Hypertension and Related Mechanisms

BACKGROUND

This case-control study aimed to determine whether there were differences between patients with essential hypertension with accessory renal arteries (ARAs) and those without ARAs.

METHODS AND RESULTS

The enrolled patients with essential hypertension were divided into the ARA group (n=200) and control group without ARAs (n=238). After propensity matching, 394 patients (197 in each of the 2 groups), were included. The 24-hour BP (4.33/2.43 mm Hg) and daytime BP (4.48/2.61 mm Hg) of patients in the ARA group were significantly higher than those of the control group (P<0.05). The flow-mediated dilation was lower in the ARA group (5.98±2.70 versus 5.18±2.66; P<0.05). In correlation analysis, the horizontal plasma aldosterone concentration had the highest correlation with 24-hour, daytime, and nighttime systolic BP (r=0.263, 0.247, and 0.243, respectively; P<0.05) and diastolic BP (r=0.325, 0.298, and 0.317, respectively; P<0.05). As for multivariate regression analysis, plasma aldosterone concentration was a significant risk factor for elevated 24-hour, daytime, and nighttime systolic BP (β=0.249 [95% CI, 0.150-0.349], 0.228 [95% CI, 0.128-0.329], and 0.282 [95% CI, 0.187-0.377], respectively; P<0.05) and elevated diastolic BP (β=0.289 [95% CI, 0.192-0.385], 0.256 [95% CI, 0.158-0.353], and 0.335 [95% CI, 0.243-0.427], respectively; P<0.05). Direct renin concentration was also a risk factor for 24-hour and daytime BPs, whereas heart rate was a risk factor correlated with 24-hour, daytime, and nighttime diastolic BP (all P<0.05). For the mixed-effects model for repeated measures, the results were similar to results of the multivariate regression analysis (all P<0.05).

CONCLUSIONS

ARAs could contribute a higher BP of patients with essential hypertension and might promote the development of essential hypertension. The mechanism might be related to overactivation of the renin-angiotensin-aldosterone system and sympathetic nervous system.

Accessory renal arteries - a source of hypertension: A case report

BACKGROUND

Secondary hypertension is a relatively rare condition most commonly caused by renovascular disease due to atherosclerotic vascular disease or fibromuscular dysplasia. Although accessory renal arteries are frequent, to date, only six cases of secondary hypertension determined by their existence have been reported.

CASE SUMMARY

We describe a case of a 39-year-old female who came to the emergency department with an urgent hypertensive crisis and hypertensive encephalopathy. Despite normal renal arteries, the computed tomography angiography revealed an inferior polar artery with 50% stenosis of its diameter. Conservative treatment with amlodipine, indapamide and perindopril was adopted, leading to blood pressure control within one month.

CONCLUSION

To the best of our knowledge, there are controversies regarding accessory renal arteries as a potential etiology for secondary hypertension, but the seven similar cases already described, along with the current case, could reinforce the necessity of more studies concerning this subject.

Relationship between accessory renal arteries and resistant hypertension: A cohort study

BACKGROUND

Resistant hypertension (RHT) is a major health care concern affecting 20 to 30% of hypertensive patients and increasing cardiovascular risk. Recent renal denervation trials have suggested a high prevalence of accessory renal arteries (ARA) in RHT. Our objective was to compare the prevalence of ARA in RHT vs. non-resistant hypertension (NRHT).

METHODS

Eighty-six patients with essential hypertension who benefited from an abdominal CT-scan or MRI during their initial workup were retrospectively recruited in 6 French ESH (European Society of Hypertension) centers. At the end of a follow-up period of at least 6 months, patients were classified between RHT or NRHT. RHT was defined as uncontrolled blood pressure despite the optimal doses of three antihypertensive agents of which one is a diuretic or similar, or controlled by ≥ 4 medications. Blinded independent central review of all radiologic renal artery charts was performed.

RESULTS

Baseline characteristics were: age 50±15 years, 62% males, BP 145±22/87±13mmHg. Fifty-three (62%) patients had RHT and 25 (29%) had at least one ARA. Prevalence of ARA was comparable between RHT (25%) and NRHT patients (33%, P=0.62), but there were more ARA per patient in NRHT (2±0.9) vs. RHT (1.3±0.5, P=0.05), and renin levels were higher in ARA group (51.6±41.7 mUI/L vs. 20.4±25.4 mUI/L, P=0.001). ARA were similar in diameter or length between the 2 groups.

CONCLUSIONS

In this retrospective series of 86 essential hypertension patients, we found no difference in the prevalence of ARA in RHT and NRHT. More comprehensive studies are needed to answer this question.