Spontaneously Resolving Hyperreninemic Hypertension Caused by Accessory Renal Artery Stenosis in a 13-Year-Old Girl: A Case Report

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.

Renovascular hypertension following by juxtaglomerular cell tumor: a challenging case with 12-year history of resistant hypertension and hypokalemia

BACKGROUND

Adolescents with secondary hyperaldosteronism often present with severe and treatment-resistant hypertension, along with hypokalemia. Renovascular hypertension is frequently caused by renal artery stenosis, primarily due to atherosclerosis and fibromuscular dysplasia (FMD). The presence of an accessory renal artery (ARA) is a common anatomical variation that can contribute to secondary renal vascular hypertension. However, FMD occurring in the ARA is a rare cause of renal vascular hypertension. Juxtaglomerular cell tumor (JGCT) represents a rare etiology of renal hypertension. The co-occurrence of the pathogenic ARA with JGCT is infrequently reported in the existing literature.

CASE PRESENTATIONS

This case study presents a young individual with a 12-year history of resistant hypertension, initially diagnosed with pathogenic ARA but later confirmed as JGCT 4 years later. Following surgery for JGCT, the patient experienced only temporary stabilization of blood pressure without anti-hypertensive medication. Stenosis of the ARA was definitively diagnosed one and a half years post-surgery, with FMD occurring on the ARA strongly suspected. The patient underwent balloon dilatation angioplasty 3 years later, leading to sustained blood pressure stability with the use of two medications.

CONCLUSIONS

The case study discussed herein involves a patient with resistant hypertension initially diagnosed with ARA but later determined to have late-onset JGCT and renal artery stenosis. It is imperative to consider atypical JGCT in young patients exhibiting resistant hypertension, hypokalemia, and hyperreninemia. Adequate management of renal artery stenosis is crucial in the management of hyperreninemic hypertension.

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.

SHOULD AN ACCESSORY RENAL ARTERY BE CONSIDERED AS A CAUSE OF HYPERTENSION IN ADOLESCENTS: A CASE REPORT

The role of an accessory renal artery in the pathogenesis of hypertension is still controversial. In this report, we describe a previously healthy 16-year-old girl with an accessory right renal artery who presented with hypertensive urgency (no progressive target organ dysfunction). Initial workup other than hypercholesterolemia and mild proteinuria was normal with no signs of other target organ damage. Further evaluation was aimed at determining the possible cause of secondary hypertension. High normal plasma renin with elevated plasma aldosterone led to a suspicion of renovascular hypertension. Magnetic resonance angiography and later computed tomography angiography showed two non-stenotic right renal arteries. Another diagnostic workup was normal. A satisfactory blood pressure control was eventually achieved with combination therapy including angiotensin-converting enzyme inhibitor. We conclude that although non-stenotic, an accessory renal artery should be considered as a possible cause of renovascular hypertension in children and adolescents even in the absence of hyperreninemia.

Accessory Renal Artery Stenosis and Secondary Hypertension

Background

Secondary hypertension is an uncommon cause of hypertension with extensive workup not recommended in most patients; however, further evaluation is generally recommended in young patients presenting with hypertension. Case Presentation. A 31-year-old female presented with history of elevated blood pressures. Secondary hypertension workup revealed no laboratory abnormalities; however, renal artery ultrasound demonstrated a left superior accessory artery and suspected bilateral renal vein congestion that was further evaluated with renal CT with contrast. Renal CT showed ostial stenosis of the left accessory renal artery. In addition, compression of the left renal vein between aorta and superior mesenteric artery was also noted, consistent with nutcracker syndrome. Hypertension was suspected to be secondary to stenosis of the accessory renal artery. Upon consultation with interventional radiology, pharmacologic treatment was recommended, and blood pressure control was ultimately achieved with a single agent. Discussion. Renovascular etiologies are responsible for 1% of cases of mild hypertension and up to 45% of severe hypertension. Accessory renal arteries are a normal anatomical variant in approximately 30% of the population. Secondary hypertension due to stenosis of an accessory renal artery is rare with very few cases described in case reports.

Conclusion

Though hypertension secondary to accessory renal artery stenosis is rare and not well published in medical literature, few case reports, including this one, demonstrate that accessory renal artery stenosis can be an underlying etiology of hypertension.