Page 5 - Carotid and peripheral vascular interventions textbook

CHAPTER 10 • RENAL ARTERY INTERVENTION

The location is often bilateral and frequently ostial or developing progressive azotemia secondary to ischemia
proximal with perirenal aortic wall involvement. Aneurysmal (a rise in serum creatinine of >30%), or unexplained
lesions have rarely been reported. Immunosuppressive hypokalemia (secondary aldosteronism), or azotemia that is
therapy is important to slow the inf ammatory process drug-induced (administration of ACEI or ARBs), should be
and prevent restenosis after revascularization. examined for RAS (22). The presence of an abdominal or
Extrinsic compression of the renal artery caused by f ank bruit or atherosclerotic disease appearing elsewhere
a f bromuscular band beginning from the diaphragm is a in the body can increase the likelihood of RAS. Kidney
rare condition. This disorder causes systemic hypertension size is also important. Prolonged decrease of blood f ow
associated with kinking of the renal artery and stenosis. with tissue hypoxia causes irreversible kidney damage and
Surgical decompression is mandatory in all cases (21). f brosis, so-called “ischemic nephropathy”. An atrophic
Other causes of renal artery stenosis such as dissection or kidney (length <7cm) or a size discrepancy between
embolus can also be treated with endovascular techniques. the two kidneys of larger than 1.5 cm are important
clues of a possible severe stenosis of the renal artery
supplying the small kidney. Finally, recurrent episodes
Table 10-1. Etiologies of renal artery stenosis. of CHF, or impaired left ventricular systolic function,
or unexplained f ash pulmonary edema without signif cant
Atherosclerosis
myocardial ischemia may result from stenosis of the
Fibromuscular dysplasia (FMD)
renal artery of a solitary kidney, or severe bilateral RAS
Extrinsic f brous band
(Pickering syndrome). These conditions should be
Renal artery dissection
considered a hypertensive emergency that will benef t
Aortic dissection
Arterial embolus from an urgent endovascular revascularization. Table 10-2
Aortic endograft occluding the renal artery summarizes the clinical indicators for the diagnosis of
Miscellaneous: RAS (23).
Autoimmune diseases
(e.g., Takayasu’s arteritis, polyarteritis nodosa)
Hypercoagulable state with renal infarction Table 10-2. Clinical clues to the diagnosis of
(e.g., Lupus anticoagulant) renal artery stenosis.
Malignancy encircling the renal artery
(e.g., Renal cell carcinoma, pheochromocytoma) • Onset of hypertension before the age of 30 years
• Onset of severe hypertension after the age of 55 years, when 253
associated with CKD or heart failure
• Hypertension and abdominal bruit
CLINICAL PRESENTATIONS • Rapid and persistent worsening of previously controlled
hypertension
RAS is assoiciated with a variety of clinical manifes- • Resistant hypertension (i.e., other secondary causes unlikely
tations as shown in Fig. 10-4. Symptoms can range from and target blood pressure not achieved despite four drug
classes including a diuretic and a mineralocorticoid-receptor
mild-to-severe uncontrolled hypertension to worsening
antagonist in appropriate doses)
renal function and accelerated cardiovascular (CV) events,
• Hypertensive crisis (i.e., acute renal failure, acute heart failure,
such as unstable angina and congestive heart failure (CHF).
hypertensive encephalopathy, or grade 3-4 retinopathy)
Many patients with RAS persist clinically asymptomatic • New azotemia or worsening of renal function after treatment
because of the large kidney functional reserve and present with RAAS blockers
as an incidental f nding during imaging of other vessels. • Unexplained atrophic kidney or discrepancy in kidney size
Hypertension with sudden onset in persons <30 years of (>1.5cm) or unexplained renal failure
age usually is a manifestation of FMD. If the diagnosis • Flash pulmonary edema
of hypertension is initially made in a patient >55 years
CKD, chronic kidney disease; RAAS, renin-angiotensin-
of age who present with malignant, accelerated or aldosterone system
resistant hypertension, ARAS should be considered. Patients