Renovascular hypertension - imaging and treatment

Full text: Imaging is very important in diagnosing renovascular hypertension (RVHT). The role of color duplex Doppler, CT angiography, MR angiography and DS angiography will be presented, advantages and disadvantages discussed. The treatment of RVHT can be medical, surgical or endovascular. Endovascular treatment is a domain of vascular interventional radiology; endovascular treatment of renovascular hypertension consists of PTA alone or PTA and stenting of renal arteries in patients who have haemodynamically significant stenosis of renal artery due to fibromuscular dysplasia or atherosclerosis. Atherosclerotic renal artery stenosis results in increased production of renin, angiotensin II, aldosterone; plasma rennin activity of is increased in renal vein of ischemic kidney that retains sodium and water. Atherosclerotic lesions are typically ostial. Long-standing hypertension damages intrarenal vessels of unprotected kidney. Hypertension and renal failure may persist after removal of stenotic kidney. It usually affects older people. Fibromuscular dysplasia is non-atherosclerotic, is more common in women, occurs at younger age (average 35 yrs). Treatment of choice is PTA alone. Results are much better than in atherosclerotic RAS, where PTA + stenting are indicated. Endovascular treatment may result in complications, minor local or major complications, mostly related to the interventional technique. While PTA for the treatment of FMD is clearly indicated, the conflicting data exist over years regarding indications, benefits, complications and advantages of PTA / stent over medical therapy for treatment of atherosclerotic renovascular hypertension. Although 25-30% of patients with impaired renal function can recover glomerular filtration after revascularization, many have no apparent change in kidney function and 19-25% experience a significant loss of kidney function, some as a result of atheroemboli. The results of ASTRAL, STAR and CORAL studies will be presented. Learning objectives: to understand the clinical significance of renovascular hypertension; to learn the role of imaging in diagnosis and treatment of RVHT; to learn the technique of PTA/stenting and understand conflicting results regarding endovascular treatment of RVHT