Renal Art HTN

Question 1

Causes

Answer 1

-Cause - atherosclerotic disease (60-80%), Fibromuscular dysplasia (10-20%), others (renal art embolism, dissection/thrombosis, trauma, vasculitis, occlusion from stent graft etc)

Question 2

Fibromuscular Dysplasia (FMD)

Answer 2

-unclear pathogenesis, some positive fly hx noted (7%) -non-atheromatous, non-inflammatory vascular condition -typically women, 30-50 years -Affects mid to distal renal artery, characteristic “string of beads” appearance RF - smoking, pregnancy. Can affect other vascular beds - carotids, peripheral art -rare to have total occlusion or ischemic arthropathy

Question 3

Atherosclerotic RAS

Answer 3

-most common, usually >55, increasing prevalence with age -Men=women -risk related to burden of other CVS d/o -typically affects ostial/proximal renal art, can occur bilaterally -can have total occlusion and ischemic arthropathy–>less amendable to intervention

Question 4

CF

Answer 4

• <30 years or >50 years with new onset HTN • Abrupt onset or acceleration of prev stable BP • Malignant HTN • Flash APO • Accelerated retinopathy -AKI with ACEi

Question 5

Pickering Syndrome

Answer 5

Question 6

Investigations

Answer 6

Renin/Aldosterone levels
- elevated in UNIlateral RAS but if -ve ?bilateral. Influenced by physiological state etc - low spec, low sens

Doppler USS - sens 97%, spec 81% but operator dependent and some over estimation of stenosis. (in FMD - hard to determine degree of stenosis)

CTA Renal - good, needs IV contrast, sens 59-96%, less accurate in CKD

MRA Renal - not often used, risk of gadolinium

Angiography - Gold Standard. Risk - chol emboli, contrast nephropathy, dissection, hematoma etc

Question 7

Management

Answer 7

ACEi or ARB

RF reduction - aggressive

Angioplasty - esp for FMD