Renovascular Disease and Renal Artery Revascularization

46.1Definition and clinical presentation

Renovascular disease is a clinical syndrome characterized by renal arterial obstruction, altered kidney function, blood pressure changes, and systemic atherosclerotic risk. Atherosclerosis accounts for approximately 90% of renal-artery obstruction in adults Lao 2011. Non-atherosclerotic causes, including fibromuscular dysplasia (FMD), vasculitis, neurofibromatosis, congenital bands, extrinsic compression, and radiation injury, are more common in younger, female, and pediatric populations, or when the disease involves the mid- or distal vessel. Unlike atherosclerotic renal-artery stenosis, fibromuscular renal-artery disease is treated by balloon angioplasty (usually without stenting) and is often curable.

The clinical presentation involves substantial overlap between renovascular hypertension and ischemic nephropathy, driven by renin-angiotensin-aldosterone system (RAAS) activation and sodium retention Kerut 2006. Typical presentations include:

• Asymptomatic presentation with incidentally discovered obstruction.
• Resistant hypertension requiring multiple antihypertensive agents.
• Ischemic nephropathy with a trajectory of rapidly declining renal function.
• Recurrent flash pulmonary edema compatible with renovascular cardiac destabilization Zarrella 2024.

46.2Diagnosis and surveillance

Diagnostic imaging confirms the anatomic obstruction but does not independently mandate intervention. Duplex ultrasound is the primary modality for diagnosis and longitudinal surveillance. Cross-sectional imaging, including computed tomography angiography (CTA) and contrast or non-contrast magnetic resonance angiography (MRA), is reserved for anatomic planning when an intervention is intended Fu 2024. Assessment defines the anatomy and differentiates ostial versus mid-vessel disease, bilateral involvement, solitary functioning kidney status, renal size, and adjacent aortic plaque Lao 2011. Grade the lesion from the duplex numbers rather than reporting only its presence. A hemodynamically significant (>= 60%) stenosis raises the main renal-artery peak systolic velocity and the renal-aortic ratio (renal PSV divided by peak aortic PSV) and generates post-stenotic turbulence. In the largest duplex-versus-angiography validation series (313 patients, 606 arteries), the cutoffs giving best overall accuracy for >= 60% stenosis were a peak systolic velocity of 285 cm/s and a renal-aortic ratio of 3.7, with mean values in >= 60% lesions of 324 cm/s and 4.5 AbuRahma 2012. A parenchymal resistive index of 0.80 or higher predicts a poor blood-pressure and renal-function response to revascularization and should temper the intervention decision Radermacher 2001.

Atherosclerotic renal-artery stenosis (ARAS) is a progressive disease and a marker of diffuse systemic vascular risk. In a duplex-surveillance cohort, the cumulative 5-year incidence of stenosis progression reached approximately 51% Lao 2011. The condition is associated with progressive loss of renal mass, with renal atrophy occurring in roughly 21% of patients with 60% obstruction, and correlates with elevated coronary event rates. Long-term mortality in renovascular disease is driven principally by cardiovascular causes rather than isolated renal failure Wallace 2016.

Patients with documented ARAS and ongoing risk factors undergo serial renal duplex surveillance at least annually. Earlier reassessment is triggered if blood pressure control deteriorates, renal function declines rapidly, or pulmonary edema occurs Zarrella 2024 · Lao 2011.

46.3Medical therapy

Optimized medical therapy is the default treatment for unselected atherosclerotic renal-artery stenosis. Because ARAS is a marker of diffuse vascular risk, therapy functions as systemic cardiovascular secondary prevention rather than isolated kidney management. The baseline regimen includes statin therapy, antiplatelet therapy when otherwise indicated, targeted glycemic control, and smoking cessation ACC/AHA 2024 · Lao 2011.

Pharmacologic blood pressure control counters RAAS activation and sodium retention. Angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) are physiologically indicated; however, initiation or dose escalation requires close serum creatinine monitoring in patients with bilateral severe stenosis or a solitary functioning kidney Kerut 2006.

46.4Revascularization thresholds

Routine revascularization is not indicated for stable atherosclerotic renal-artery stenosis, as it does not improve major cardiovascular or renal outcomes over medical therapy alone. In the CORAL trial, adults with ARAS and hypertension or chronic kidney disease were randomized to stenting plus medical therapy versus medical therapy alone. At a median follow-up of 43 months, the primary composite of cardiovascular and renal events occurred in 35.1% of the stent group and 35.8% of the medical group, yielding a hazard ratio of 0.94 (95% CI 0.76 to 1.17) CORAL · 2014. While stenting produced a modest mean systolic blood pressure difference of -2.3 mm Hg, this did not reduce clinical events, nor did it confer a sustained quality-of-life advantage CORAL QoL (2025).

The Cochrane systematic review and a subsequent meta-analysis show that balloon angioplasty with or without stenting is not superior to medical therapy for mortality, stroke, or major renal endpoints, though it may produce a small reduction in diastolic blood pressure and medication burden Meta-analysis 2021 · Cochrane 2014. RADAR, a randomized trial stopped early and underpowered for its primary endpoint of renal-function change, is directionally supportive of this conclusion rather than confirmatory RADAR (2017). Intervention is therefore restricted to specific high-risk phenotypes excluded from or under-represented in the randomized trials.

The clinical pathway follows an ordered stepwise approach:

1. Establish optimized medical therapy and systemic secondary prevention as the baseline for all patients.
2. Define the clinical indication by assessing the trajectory of renal decline, the occurrence of flash pulmonary edema, and the definition of resistant hypertension.
3. In stable disease matching the CORAL inclusion criteria, continue surveillance and medical therapy alone.
4. In rapidly declining renal function or flash pulmonary edema, evaluate for revascularization.
5. In truly resistant hypertension with severe hemodynamically confirmed stenosis, select highly suitable anatomies for intervention.

46.5Intervention technique and outcomes

Atherosclerotic renal-artery disease characteristically involves the ostium and proximal third of the vessel, frequently contiguous with the adjacent aorta. Advanced presentations may include diffuse intrarenal atherosclerosis Lao 2011. Endovascular intervention must completely cover the aorto-ostial plaque shoulder to prevent residual hemodynamic compromise. Advanced renal atrophy and diffuse intrarenal atherosclerosis diminish the functional benefit of restoring main-vessel caliber. When severe ostial stenosis (>= 80%) correlates with resistant hypertension, registry data using covered stents report 94.3% primary patency at 9 months and a mean systolic blood pressure reduction of 15.7 mm Hg, accompanied by a 36-month clinically driven target-lesion revascularization rate of 7.3% and an 8.8% major adverse event rate ARTISAN (2024). Open surgical revascularization is reserved and selective in the endovascular era: renal reconstruction performed concomitantly with aortic reconstruction for aneurysmal or occlusive disease, failed or anatomically unsuitable endovascular therapy, and complex ostial, branch, or segmental disease. Aortorenal bypass and renal endarterectomy are the mainstay operations, with hepatorenal or splenorenal bypass as extra-anatomic options when the aorta is too diseased for a proximal anastomosis ACC/AHA 2024.

Complications associated with renal angioplasty and stenting include groin hematoma (approximately 6.5%), renal-artery or kidney perforation and dissection (2.5%), femoral pseudoaneurysm (< 1%), and peri-procedural death (0.4%) Cochrane 2014.

Post-procedural surveillance monitors patency alongside the specific clinical indication. Evaluating blood pressure response, medication burden, creatinine trajectory, or the recurrence of pulmonary edema is required to ascertain whether the intervention was clinically successful, rather than solely technically patent Kerut 2006.

46.6Transplant renal-artery stenosis

Transplant renal-artery stenosis (TRAS) is a discrete clinical and technical entity. Risk factors consistently include recipient cardiovascular comorbidity, delayed graft function, specific surgical anastomotic factors, and donor age TRAS Meta-analysis 2026. Its prevalence varies globally, largely driven by differing institutional definitions and screening strategies TRAS Meta-analysis 2024.

Surveillance in higher-risk transplant recipients involves early and symptom-triggered duplex ultrasound. Confirmatory cross-sectional imaging or angiography is performed when clinical graft dysfunction or resistant hypertension emerges and the resulting anatomic findings will alter management TRAS Meta-analysis 2026 · TRAS Meta-analysis 2024.

46.7Areas of controversy

The adjunctive use of pharmacological strategies during intervention, such as mitochondrial-targeted peptides (elamipretide) aimed at mitigating ischemia-reperfusion injury, remains investigational and is not established for routine clinical use Elamipretide Trial 2017.

Elevated serum uric acid has been identified in registries as a marker for worse renal and blood-pressure outcomes following renal-artery stenting, though its utility as an independent criterion to exclude patients from intervention is not uniformly established Cohort 2019.

The established complication rates for renal stenting are largely derived from older, aggregate systematic reviews; whether contemporary devices and stricter patient selection yield different complication profiles remains uncertain Cochrane 2014. Additionally, absolute rates of duplex-defined progression may be lower in contemporary practice owing to intensified systemic cardiovascular risk-factor control compared with historical cohorts Lao 2011.