CHRONIC VASCULAR DISEASES(Vasorenal Hypertension)

BYASOGWA INNOCENT KINGSLEY

ML-508

Anatomy of Kidney

Renal Vasculaturea. Renalis, branches off from abdominal aorta, just

below superior mesenteric artery

Renal Physiology

Etiology Of Vasorenal HypertensionCongenital

Fibromuscular dysplasia( common)AtresiaHypoplasia of renal arteryAngiomaAneurysmArteriovenous fistula

AcquiredAtherosclerosis(common)Nonspecific aortoarteritisNephroptosisThrombosis and EmbolismTraumaTumour

Fibromuscular dysplasia

Congenital diseaseAffects women more frequentlyCommonest cause of

renovascular hypertension among young patients

Degenerative disease affecting Tunica intima and Tunica Media of arteries

Multiple stenosis with intermittened dilatation of the artery

Common cause of aneurysm in smaller branches of renal artery

Atherosclerosis

Pathogenesis Vasorenal Hypertension

Decrease in Renal blood flow stimulates juxtaglomerular apparatus – increase Renin secretion

Increased renin causes conversion of angiotensinogen to angiotensin 1 and then to angiotensin 2

Acting on the vessels causing vasoconstriction and acting on the adrenal cortex, releasing aldosterone

Increased Sodiun and water retension therefroe increasing extracellular fluid causing leg edema and increased blood pressure.

Reduced glomerular filtration, Atrophy of affected kidney, renal failure, Hypertrophy of the contralateral kidney, Development of atherosclerosis of the contralateral renal artery

Clinical SymptomsComplaints of high blood pressure

- headache( particularly at the back of the head and in the morning), dizziness, tinnitus( buzzing or hissing in the ear), vertigo, altered vision or fainting episodes, palpitation, chest pains

Decreased renal functionConcommitent disturbances in other arterial beds

- Pain in lower and upper extremities etc.

DiagnosisAnamnesis

HypertensionPain in loins and lower back

Auscultation-murmur(abdominal bruits) on inferior costal margin of affected side

Doppler ultrasonography Renography (isotope method)Angiography

Doppler US of Renal Artery

http://www.gehealthcare.com/usen/ultrasound/education/products/cme_ren_art.html#6

Angiography

Severe renal artery stenosis, diagnosis confirmed by following angiography

http://www.bmj.com/content/320/7242/1124.full

Differential DiagnosisPheochromocytomaCushing’s DiseaseCon’s SyndromeThyroid Diseases

Conservative TreatmentIndicated for old patients with systemic vascular

pathologyTreatment of hypertension

Enalapril 20mg/day (ACE-inhibitor)Hydrochlorothiazide 12.5 mg/day

Treatment of Acute Thrombosisrt-PA (Alteplas)

Prophylaxis of thrombosisAspirin 75 mg daily (Clopidogrel 75 mg daily combined with Aspirin)Simvastatin 20mg/day (esp. Indicated for obese ptnt.)

Surgical TreatmentThrombendarterectomy with patch graftRenal artery bypass surgeryNephrectomy

Thrombendarterectomy with Patch graft

Renal artery bypass surgery

Endovascular TreatmentPercutaneous transluminal angioplasty (Balloon

angioplasty)

Placement of Stent

ComplicationsHemorrhageInfectionEarly and Late Thrombosis of StentOcclusion, dissection and perforation of renal

arteryContrast nephrotoxicity

PrognosisUntreated:

Severe hypertension with damage to cardiovascular systemBilateral renal failure Intoxication, Encephalopathy, Coma, Death

Treated (Depends on the duration of pathology and level of organ damage)Focal disease i.e. Atherosclerotic disease limited to one renal

artery; good prognosis with lowered arterial blood pressure and decreased antihypertensive medication.

Diffuse generalised atherosclerosis with secondary damages to kidney and other organs; poor prognosis with risk of developing firther organ damage.