Contemporary management of atherosclerotic renovascular disease

Results of the major randomized clinical trials of renal stenting and implications for future treatment strategies

The management of atherosclerotic renovascular disease remains an area of controversy. This review details the results of major clinical trials and their implications for contemporary treatment recommendations for affected patients.

A STRUCTURE-MOTIVATED MODEL OF THE PASSIVE MECHANICAL RESPONSE OF THE PRIMARY PORCINE RENAL ARTERY

The primary renal arteries transport up to one fourth of cardiac output to the kidneys for blood plasma ultrafiltration, with a functional dependence on the vessel geometry, composition and mechanical properties. Despite the critical physiological function of the renal artery, the few biomechanical studies that have focused on this vessel are either uniaxial or only partially describe its bi-axial mechanical behavior. In this study, we quantify the passive mechanical response of the primary porcine renal artery through bi-axial mechanical testing that probes the pressure-deformed diameter and pressure-axial force relationships at various longitudinal extensions, including the in-vivo axial stretch ratio. Mechanical data are used to parameterize and validate a structure-motivated constitutive model of the arterial wall. Together, experimental data and theoretical predictions of the stress distribution within the arterial wall provide a comprehensive description of the passive mechanical response of the porcine renal artery.

After ASTRAL and STAR — whither renal artery stenting?

ASTRAL and STAR, two recent prospective randomized trials to compare renal artery stenting with optimal medical management versus optimal medical management alone for patients with renal insufficiency and renal artery stenosis, have concluded that there was no additional benefit to stenting. Patient selection and methodological issues in these studies cast doubt on the validity of their results and conclusions for patients with renal insufficiency and physiologically (hemodynamically) significant renal artery stenosis, i.e. true ischemic nephropathy.

Epidemiology and natural history of atherosclerotic renovascular disease

Atheromatous renovascular disease (ARVD) is increasingly suspected and diagnosed, and it commonly presents to several different clinical specialties. In this review, the epidemiology, risk factors, comorbid disease associations, natural history, and prognosis of ARVD is described. Atheromatous renovascular disease is strongly associated with macrovascular pathology in other important vascular beds, especially the coronary, aortoiliac and iliofemoral circulations, and also with structural and functional heart disease. These clinicopathologic relationships contribute to the high morbidity and mortality associated with the condition. Understanding of the natural history of renal artery stenosis may enable intensified treatment strategies to reduce associated risk and improve patient prognosis.