ANSWER 37
This woman has hypertension due to renovascular disease. The vast majority of cases
of hypertension are due to essential hypertension. Risk factors for essential hypertension
include a family history of hypertension, obesity and lack of exercise. She does not have
paroxysmal symptoms of sweating, palpitations and anxiety to suggest a phaeochromocy-
toma. There are no clinical features to suggest coarctation of the aorta (radiofemoral delay)
or neurofibromatosis (café-au-lait spots/neurofibromas). Serum potassium is not low mak-
ing Conn’s syndrome or Cushing’s syndrome unlikely. The principal abnormality is the
modestly raised creatinine suggesting mildly impaired renal function. The absence of
haematuria and proteinuria excludes glomerulonephritis. Therefore renovascular disease
needs to be considered. The absence of a renal bruit does not exclude the possibility of reno-
vasculardisease. The renal angiogram shows bilateral fibromuscular dysplasia (FMD).
The commonest cause of renovascular disease is atherosclerotic renal artery stenosis (ARAS).
This is common in elderly patients with evidence of generalized atherosclerosis (peripheral
vascular disease and coronary artery disease). Ultrasound will often show small kidneys, and
renal impairment is common. ARAS is a common cause of end-stage renal failure in the
elderly.
At this woman’s age atherosclerotic renovascular disease is very unlikely. FMD is the second
most common cause of renovascular disease. The commonest form is medial fibroplasia with
thinning of the intima and media leading to formation of aneurysms alternating with
stenoses, leading to the classic ‘string of beads’ appearances on angiography. It predomi-
nantly affects young and middle-aged women with a peak incidence in the fourth decade of
life. Cigarette smoking is a risk factor. FMD usually presents with hypertension, but can
rarely present with ‘flash’ pulmonary oedema. FMD can also affect the carotid arteries caus-
ing a variety of neurological symptoms.
Treatment is with percutaneous transluminal renal angioplasty. Unlike atheromatous reno-
vasculardisease, the hypertension in FMD cases is often cured leading to complete cessa-
tion of blood pressure medication. Restenosis is rare.
- FMD is an important cause of hypertension in young and middle-aged women.
- Renal artery angioplasty will improve or even cure hypertension in many patients with
FMD. - FMD is a very rare cause of end-stage renal failure.