Renal artery stenosis
Classification and external resources
Renal artery is #3
ICD-9	440.1
DiseasesDB	11255
MedlinePlus	001273
eMedicine	med/2001
MeSH	D012078

Renal artery stenosis is the narrowing of the renal artery, most often caused by atherosclerosis or fibromuscular dysplasia. This narrowing of the renal artery can impede blood flow to the target kidney. Hypertension and atrophy of the affected kidney may result from renal artery stenosis, ultimately leading to renal failure if not treated.

Contents 1 Signs and symptoms 2 Diagnosis 3 Etiology 4 Pathophysiology 5 Treatment 5.1 Atherosclerotic renal artery stenosis 5.2 Fibromuscular dysplasia 6 See also 7 References

[edit] Signs and symptoms

Most cases of renal artery stenosis are asymptomatic, and the main problem is high blood pressure that cannot be controlled with medication. Deterioration in renal function may develop if both kidneys are poorly supplied, or when treatment with an ACE inhibitor is initiated. Some patients present with episodes of flash pulmonary edema (sudden left ventricular heart failure).^[1]

[edit] Diagnosis

• refractory hypertension - high blood pressure that cannot be controlled adequately with antihypertensives
• auscultation (with stethoscope) - bruit ("rushing" sound) on affected side, inferior of the costal margin
• captopril challenge test
• captopril test dose effect on the differential renal function as measured by MAG3 scan.^[2]
• renal artery arteriogram

A clinical prediction rule is available to guide diagnosis.^[3]

[edit] Etiology

Atherosclerosis is the predominant cause of renal artery stenosis in the majority of patients, usually those with a sudden onset of hypertension at age 50 or older. Fibromuscular dysplasia is the predominant cause in young patients, usually females under 40 years of age. A variety of other causes exist. These include arteritis, renal artery aneurysm, extrinsic compression (e.g., neoplasms), neurofibromatosis, and fibrous bands.

[edit] Pathophysiology

The macula densa of the kidney senses a decreased systemic blood pressure owing to the reduced blood flow through the narrowed artery. The response of the kidney to this perceived decreased blood pressure is activation of the renin-angiotension aldosterone system, which normally counteracts low blood pressure but in this case leads to hypertension (high arterial blood pressure). The decreased perfusion pressure (caused by the stenosis) leads to decreased blood flow (hypoperfusion) to the kidney and a decrease in the GFR. If the stenosis is longstanding and severe the GFR in the affected kidneys never increases again and (prerenal) renal failure is the result.

[edit] Treatment

[edit] Atherosclerotic renal artery stenosis

It is initially treated with medications. These include statins, antiplatelet agents and drugs for control of blood pressure. When high-grade renal artery stenosis is documented and blood pressure cannot be controlled with medication, or if renal function deteriorates, invasive procedure may be resorted to. The most commonly used invasive procedure is angioplasty with or without stenting. A 2003 meta-analysis found that angioplasty was safe and effective in this context.^[4] There are ongoing clinical trials to compare medical management and angioplasty with stenting to medical management alone. These include CORAL and ASTRAL, both scheduled to report results in 2010. In addition to angioplasty, surgical resection and anastomosis are a rarely used option.

[edit] Fibromuscular dysplasia

Angioplasty with or without stenting is the best option for the treatment of renal artery stenosis due to fibromuscular dysplasia.

[edit] See also

• Renovascular hypertension

[edit] References

v • d • e Cardiovascular disease: vascular disease · Circulatory system pathology (I70-I99, 440-456) Arteries, arterioles and capillaries Inflammation Arteritis (Aortitis) · Buerger's disease Arterial occlusive disease/ peripheral vascular disease Arteriosclerosis Atherosclerosis (Foam cell, Fatty streak, Atheroma, Intermittent claudication) · Monckeberg's arteriosclerosis · Arteriolosclerosis (Hyaline, Hyperplastic, oxycholesterol, cholesterol, LDL, trans fat) Stenosis Renal artery stenosis · Carotid artery stenosis Other Fibromuscular dysplasia · Degos disease · Aortoiliac occlusive disease · Raynaud's phenomenon/Raynaud's disease · Erythromelalgia Aneurysm/dissection/ pseudoaneurysm torso: Aortic aneurysm (Thoracic aortic aneurysm, Abdominal aortic aneurysm) · Aortic dissection · Coronary artery aneurysm head/neck: Cerebral aneurysm · Intracranial berry aneurysm · Carotid artery dissection · Vertebral artery dissection · Familial aortic dissection Vascular malformation Arteriovenous fistula · Telangiectasia (Hereditary hemorrhagic telangiectasia) Vascular nevus Spider angioma · Halo nevus · Cherry hemangioma Veins Inflammation Phlebitis Venous thrombosis/ Thrombophlebitis primarily lower limb (Deep vein thrombosis) abdomen (May-Thurner syndrome, Portal vein thrombosis, Budd-Chiari syndrome, Renal vein thrombosis) upper limb/torso (Paget-Schroetter disease, Mondor's disease) head (Cerebral venous sinus thrombosis) Post-thrombotic syndrome Varicose veins Varicocele · Gastric varices · Portacaval anastomosis (Hemorrhoid, Esophageal varices, Caput medusae) Other Superior vena cava syndrome · Inferior vena cava syndrome · Venous ulcer · Chronic venous insufficiency · Chronic cerebrospinal venous insufficiency Arteries or veins Vasculitis · Thrombosis · Embolism (Pulmonary embolism, Cholesterol embolism, Paradoxical embolism) · Angiopathy (Macroangiopathy, Microangiopathy) Blood pressure Hypertension Hypertensive heart disease · Hypertensive nephropathy · Essential hypertension  · Secondary hypertension (Renovascular hypertension) · Pulmonary hypertension · Malignant hypertension · Benign hypertension · Systolic hypertension · White coat hypertension Hypotension Orthostatic hypotension vascular navs: anat/physio/dev, noncongen/systemic vasculitis/congen/neoplasia, symptoms+signs/eponymous, proc

v • d • e Urinary system · Pathology · Urologic disease / Uropathy (N00–N39, 580–599) Abdominal Nephropathy/ (nephritis+ nephrosis) Glomerulopathy/ glomerulitis/ (glomerulonephritis+ glomerulonephrosis) Primarily nephrotic Non-proliferative .0 Minimal change · .1 Focal segmental · .2 Membranous Proliferative .3 Mesangial proliferative · .4 Endocapillary proliferative .5/.6 Membranoproliferative/mesangiocapillary By condition Diabetic · Amyloidosis Primarily nephritic, .7 RPG Type I RPG/Type II hypersensitivity Goodpasture's syndrome Type II RPG/Type III hypersensitivity Post-streptococcal · Lupus (DPN) · IgA/Berger's Type III RPG/Pauci-immune Wegener's granulomatosis · Microscopic polyangiitis Tubulopathy/ tubulitis Proximal RTA (RTA 2) Thick ascending Bartter syndrome Distal convoluted Gitelman syndrome Collecting duct Liddle's syndrome · RTA (RTA 1) · Diabetes insipidus (Nephrogenic) Renal papilla Renal papillary necrosis Major calyx/pelvis Hydronephrosis · Pyonephrosis · Reflux nephropathy Any/all Acute tubular necrosis Interstitium Interstitial nephritis (Pyelonephritis, Danubian endemic familial nephropathy) Any/all General syndromes Renal failure (Acute renal failure, Chronic renal failure) · Uremic pericarditis · Uremia Vascular Renal artery stenosis · Hypertensive nephropathy · Renovascular hypertension Other Analgesic nephropathy · Renal osteodystrophy · Nephroptosis · Abderhalden-Kaufmann-Lignac syndrome Ureter Ureteritis · Ureterocele · Megaureter Pelvic Bladder Cystitis (Interstitial cystitis/painful bladder syndrome, Hunner's ulcer, Trigonitis, Hemorrhagic cystitis) · Neurogenic bladder · Vesicointestinal fistula · Vesicoureteral reflux Urethra Urethritis (Non-gonococcal urethritis) · Urethral syndrome · Urethral stricture/Meatal stenosis Any/all Obstructive uropathy · Urinary tract infection · Retroperitoneal fibrosis · Urolithiasis (Kidney stone, Renal colic) · Malacoplakia urinary system navs: anat/physio/dev, noncongen/acid+base/congen/neoplasia, symptoms+signs/eponymous, proc