What is the significance of less than 60 percent renal artery stenosis (RAS) in a 9-year-old boy with mild hypertension (elevated systolic and diastolic blood pressure)?

From the Guidelines

Renal artery stenosis less than 60 percent in a 9-year-old boy with mild hypertension is clinically significant but not immediately critical, and the recommended approach is close monitoring of blood pressure with lifestyle modifications. The condition is characterized by a mild narrowing of the artery that supplies blood to the kidney, which can cause hypertension through activation of the renin-angiotensin-aldosterone system as the kidney responds to perceived reduced blood flow 1. According to the 2024 ESC guidelines for the management of elevated blood pressure and hypertension, renovascular hypertension is a condition where renal artery occlusion or stenosis decreases renal perfusion pressure to a level that activates the renin–angiotensin–aldosterone system (RAAS), thereby raising BP 1. Key points to consider in the management of this condition include:

• Close monitoring of blood pressure with regular measurements every 3-6 months
• Lifestyle modifications including reduced sodium intake (less than 2,300 mg daily), regular physical activity (60 minutes daily), and maintaining healthy weight
• Medication is typically not needed for stenosis below 60% unless blood pressure remains consistently elevated despite lifestyle changes
• If medication becomes necessary, ACE inhibitors like enalapril (0.08-0.6 mg/kg/day divided into two doses) would be considered, but with caution and close monitoring of kidney function 1
• Regular ultrasound follow-up every 6-12 months is important to monitor for progression of the stenosis, as children may experience worsening as they grow. It is essential to note that bystander renal artery stenosis may be present in patients with essential hypertension, without causing secondary hypertension due to RVH, and fibromuscular dysplasia is a systemic disease, so CT or MRI angiography from head to pelvis is recommended in patients with FMD-RVH 1.

From the Research

Significance of Less Than 60 Percent Renal Artery Stenosis

• The significance of less than 60 percent renal artery stenosis (RAS) in a 9-year-old boy with mild hypertension is not clearly defined in the provided studies, as most studies focus on RAS with at least 60% stenosis 2, 3, 4.
• However, it is known that RAS can be a cause of pediatric hypertension, and early detection and treatment are crucial to prevent long-term complications 5, 6.
• A study reported a case of a 9-year-old boy with uncontrolled hypertension who was diagnosed with bilateral RAS, highlighting the importance of considering RAS in the differential diagnosis of pediatric hypertension 6.

Diagnosis and Management

• The diagnosis of RAS can be challenging, and imaging studies such as renal Doppler ultrasonography, computed tomography angiography, and magnetic resonance imaging may not always detect anatomical abnormalities 6.
• In some cases, percutaneous transluminal angioplasty may be used as a diagnostic and therapeutic approach to confirm the diagnosis of RAS 6.
• Management of RAS may involve conservative therapy, endovascular intervention, or surgical intervention, depending on the severity of the disease and the presence of associated conditions 2, 3, 4.

Clinical Implications

• The presence of less than 60 percent RAS in a 9-year-old boy with mild hypertension may not necessarily require invasive treatment, but close monitoring and follow-up are essential to prevent progression of the disease 3, 4.
• Early detection and treatment of RAS can improve blood pressure control and prevent long-term complications such as kidney damage and cardiovascular disease 2, 5, 6.