Investigating progressive unexplained renal impairment and hypertensionBMJ 2007; 335 doi: https://doi.org/10.1136/bmj.39363.672743.AD (Published 22 November 2007) Cite this as: BMJ 2007;335:1094
- L A Ratnam, interventional radiology fellow,
- S R Nelson, consultant nephrologist,
- A M Belli, consultant interventional radiologist
- Radiology Department, St George's Hospital, London SW17 0QT
- Correspondence to: A M Belli
• Renal artery stenosis is a common condition in elderly people presenting with renal impairment and hypertension
• Ultrasonography is the first line method of imaging as it is safe, inexpensive, and widely available and readily detects obstructive causes. However, a normal renal ultrasound study does not exclude the diagnosis of renal artery stenosis
• Magnetic resonance angiography and computed tomography angiography are the preferred non-invasive imaging methods to identify renal artery stenosis. Digital subtraction angiography should be reserved for patients in whom endovascular intervention is being considered or when non-invasive imaging is inconclusive
A 79 year old hypertensive man was referred for investigation of impaired renal function. At the time of referral he was taking a single antihypertensive agent and his blood pressure measured 170/85 mm Hg. He smoked 50 g of pipe tobacco a week. He had no other medical history of note. No renal artery bruit was detected, and the remaining clinical examination was unremarkable. His serum creatinine concentration at presentation was 116 mmol/l (normal range 60-110 mmol/l), representing an estimated glomerular filtration rate of 55 ml/min. Urine analysis was normal. His serum cholesterol concentration was raised (5.9 mmol/l (normal range 3.0-5.2 mmol/l). Over two years, his blood pressure remained raised despite an increase in his antihypertensive treatment, and his serum creatinine concentration rose to 206 mmol/l.
What is the next investigation?
Unexplained, progressive renal impairment, and hypertension that is poorly controlled despite the use of multiple drugs, warrants further investigation. The absence of blood and protein in the urine points away from intrinsic renal disease. Both a prerenal cause (such as renal artery stenosis) and …