Kidney Intrinsic Mechanisms as Novel Targets in Renovascular Hypertension.

Almost a hundred years have passed since obstruction of the renal artery has been recognized to raise blood pressure. By now chronic renovascular disease (RVD) due to renal artery stenosis is recognized as a major source of renovascular hypertension and renal disease. In some patients, RVD unaccompanied by noteworthy renal dysfunction or blood pressure elevation may be incidentally identified during peripheral angiography. Nevertheless, in others, RVD might present as a progressive disease associated with diffuse atherosclerosis, leading to loss of renal function, renovascular hypertension, hemodynamic compromise, and a magnified risk for cardiovascular morbidity and mortality. Atherosclerotic RVD leads to renal atrophy, inflammation, and hypoxia but represents a potentially treatable cause of chronic renal failure because until severe fibrosis sets in the ischemic kidney, it retains a robust potential for vascular and tubular regeneration. This remarkable recovery capacity of the kidney begs for early diagnosis and treatment. However, accumulating evidence from both animal studies and randomized clinical trials has convincingly established the inadequate efficacy of renal artery revascularization to fully restore renal function or blood pressure control and has illuminated the potential of therapies targeted to the ischemic renal parenchyma to instigate renal regeneration. Some of the injurious mechanisms identified as potential therapeutic targets included oxidative stress, microvascular disease, inflammation, mitochondrial injury, and cellular senescence. This review recapitulates the intrinsic mechanisms that orchestrate renal damage and recovery in RVD and can be harnessed to introduce remedial opportunities.

Atherosclerotic renovascular disease: a clinical practice document by the European Renal Best Practice (ERBP) board of the European Renal Association (ERA) and the Working Group Hypertension and the Kidney of the European Society of Hypertension (ESH).

Atherosclerotic renovascular disease (ARVD) is the most common type of renal artery stenosis. It represents a common health problem with clinical presentations relevant to many medical specialties and carries a high risk for future cardiovascular and renal events, as well as overall mortality. The available evidence regarding the management of ARVD is conflicting. Randomized controlled trials failed to demonstrate superiority of percutaneous transluminal renal artery angioplasty (PTRA) with or without stenting in addition to standard medical therapy compared with medical therapy alone in lowering blood pressure levels or preventing adverse renal and cardiovascular outcomes in patients with ARVD, but they carried several limitations and met important criticism. Observational studies showed that PTRA is associated with future cardiorenal benefits in patients presenting with high-risk ARVD phenotypes (i.e. flash pulmonary oedema, resistant hypertension or rapid loss of kidney function). This clinical practice document, prepared by experts from the European Renal Best Practice (ERBP) board of the European Renal Association (ERA) and from the Working Group on Hypertension and the Kidney of the European Society of Hypertension (ESH), summarizes current knowledge in epidemiology, pathophysiology and diagnostic assessment of ARVD and presents, following a systematic literature review, key evidence relevant to treatment, with an aim to support clinicians in decision making and everyday management of patients with this condition.

Renovascular Hypertension with Progressive Atherosclerotic Renal Artery Stenosis in an Elderly Patient with Known Fibromuscular Dysplasia: A Case Report.

BACKGROUND Atherosclerotic renal artery stenosis (ARAS) and renovascular fibromuscular dysplasia (FMD) are 2 of the most common etiologies of renovascular hypertension. They have different pathophysiologies, risk factors, presentations, and treatment options. However, as our population ages, it can become increasingly common to see patients who previously had FMD who develop ARAS at an advanced age, indicated by recurrent renovascular hypertension. CASE REPORT We present a case of a 66-year-old female patient who, in 2007, had presented with uncontrolled hypertension. She underwent magnetic resonance angiography and was found to have bilateral FMD, for which she received balloon angioplasty to a severe lesion on the mid-right renal artery and subsequently had normalization of blood pressures and resolution of symptoms. In 2021 she returned with uncontrolled hypertension while being treated with 3 antihypertensives. Bilateral renal arteriography revealed new severe ostial stenosis of the left renal artery and a patent right renal artery in which balloon angioplasty was performed 14 years ago. Based on the angiographic pattern of this new left RAS, we concluded this lesion was caused by atherosclerosis. The left ostial lesion was treated with a bare-metal stent and the patient was continued on antihypertensive medication and statin; at follow-up 4 months later, her blood pressures had normalized. CONCLUSIONS This case features a patient who developed severe ARAS with underlying history of bilateral renal artery FMD. Clinicians need to be aware that in patients with FMD, worsening renovascular hypertension at an advanced age could indicate the development of new hemodynamically significant ARAS. These patients need repeat diagnostic testing and treatment with medial optimization with or without endovascular revascularization in the appropriate clinical setting.

Stent-Graft Placement for Radiation-Induced Abdominal Aortic Stenosis after Renal Autotransplantation.

Renovascular hypertension (RVH) is a common cause of secondary hypertension. However, there have been no reports on RVH due to radiation-induced abdominal aorta stenosis after renal autotransplantation. A 27-year-old woman with a history of neuroblastoma treated by radiation therapy and RVH treated with renal autotransplantation presented with hypertension and dyspnea. At age 19, she had experienced hypertensive heart failure due to RVH from radiation-induced left renal artery stenosis and had undergone renal autotransplantation involving the extraction of her left kidney. Her systolic blood pressure (BP) was well-controlled but had increased progressively. She was diagnosed with hypertensive heart failure and admitted to hospital. Although her dyspnea soon subsided after treatment, her BP remained high. Renal artery ultrasound revealed no obvious stenosis. The ankle brachial pressure index (ABI) showed a significant bilateral decrease to 0.71/0.71 (right/left) from 0.94/0.95 eight years before. Magnetic resonance angiography and aortic angiography revealed severe stenosis in the abdominal aorta, and the systolic pressure gradient of intra-aortic blood flow, distal and proximal to a stenotic lesion, was 58 mmHg. These arterial stenoses in the irradiated area were highly suggestive of radiation-induced vasculopathy. She finally underwent an endovascular VIABAHN VBX balloon-expandable stent-graft placement for this radiation-induced abdominal aorta stenosis, which resolved the pressure gradient. After the procedure, her ABI improved to 0.91/0.88 and her BP was well-controlled. This is the first case of successful stent-graft placement for RVH after renal autotransplantation due to radiation-induced abdominal aorta stenosis as a consequence of neuroblastoma.

Endovascular Versus Medical Management of Atherosclerotic Renovascular Disease: Update and Emerging Concepts.

Atherosclerotic renovascular disease is the most frequent cause of renovascular hypertension and its prevalence increases with age and in specific subset of patients, such as those with end-stage chronic kidney disease, heart failure, and coronary artery disease. Besides hypertension, atherosclerotic renovascular disease is responsible for several clinical manifestations, including life-threatening conditions, such as recurrent flash pulmonary edema, rapidly progressive chronic kidney disease, or acute kidney injury. Atherosclerotic renovascular disease is usually part of a more diffuse atherosclerotic process and requires a combination therapy including antihypertensive, antiplatelet and lipid-lowering agents, as well as optimization of antidiabetic treatment, if needed. Besides medical therapy, percutaneous renal angioplasty was supposed to be the most effective therapy for atherosclerotic renovascular disease, by leading to blood flow restoration. However, despite an apparently solid rationale, several randomized clinical trials failed to confirm the favorable effects of percutaneous renal angioplasty on blood pressure control, kidney function, cardiovascular and renal outcomes, previously reported in observational, retrospective and single-center cohorts, switching off the enthusiasm for this procedure. Several studies' limitations may partly account for this failure, including heterogeneity of diagnostic techniques, overestimation of the degree of renal artery stenosis, inappropriate timing of revascularization, multiple protocol revisions, frequent crossovers, and most importantly exclusion of patients at higher likelihood to respond to angioplasty. The purpose of this review is to summarize studies' potential weaknesses and provide guidance to the clinician for identification of patients who may benefit most from revascularization.

A Nine-year-old Boy with Renovascular Hypertension: Knowing Where to Look.

Renal artery entrapment (RAE) by hypertrophic diaphragmatic crura is an extremely rare cause of renovascular hypertension (RVH). Here, we report the case of a 9-year-old boy diagnosed with RVH caused by right RAE by a hypertrophic diaphragmatic crus and successfully managed with close medical monitoring. Diagnosis of this entity is easily overlooked if the optimal views are not obtained during imaging, which depends on a high index of suspicion. We would like to remind clinicians to keep this rare condition in mind when evaluating children with RVH.

Atherosclerotic renovascular disease and cardiovascular risk: new concepts.

Renal vascular hypertension (RVHT) is one of the most common secondary forms of hypertension. It is estimated that 1% to 5% of all cases of hypertension can be attributed to RVHT. RVHT is generally caused by progressive stenosis of the renal artery most often due to atherosclerosis, and less often caused by fibromuscular dysplasia. Atherosclerotic renal artery stenosis (ARAS) can lead to the development of resistant hypertension and can also cause progressive impairment of renal function. ARAS can also result in serious cardiac complications, such as flash pulmonary edema or congestive heart failure. Most patients with ARAS are characterized by the presence of left ventricular hypertrophy and diastolic dysfunction. The disease progression is associated with an increase in left ventricular mass index and cardiac dilatation. Atherosclerotic renovascular disease is recognized as a relevant risk factor for cardiovascular morbidity and mortality. Studies published so far documented ARAS as a predictor of higher cardiovascular risk and showed that mortality after incidental ARAS diagnosis is much higher than that observed in the general population. Proper recognition of the patients with ARAS who would benefit from interventional treatment is crucial, particularly for identification of patients with true resistant hypertension, flash pulmonary edema, and progressive impairment of renal function.

Hypertension crisis as the first symptom of renovascular hypertension in children.

BACKGROUND: Renovascular hypertension (RVH) is one of the main causes of hypertensive crisis (HTN-C). It is characterized by acute onset and severe disease, and early diagnosis and treatment are difficult. The objective was to describe the characteristics of RVH and factors associated with RVH leading to HTN-C in children. At present, there are few clinical studies on RVH in children with large cases in China. METHODS: This study retrospectively analyzed the clinical data of inpatient children with RVH. Patients were divided into non-hypertensive crisis (non-HTN-C) group, and HTN-C group according to the first symptoms and blood pressure. Further, HTN-C were classified as hypertensive urgency (HTN-U) or hypertensive emergency (HTN-E). RESULTS: Fifty-four pediatric cases (41 boys and 13 girls) were included. 83.3% of the RVH cases were ≥ 6 years old. Three cases were classified into the non-HTN-C group. Of the 51 HTN-C cases, 18 cases were grouped as HTN-U and 33 as HTN-E. The HTN-U group were mainly asymptomatic (50.0%, 9/18) while the HTN-E group mainly presented with neurological symptoms (72.7%, 24/33). The number of unknown etiology children was 32 (59.2%). The top three known etiologies were Takayasu's arteritis (50.0%, 11/22), congenital renal dysplasia (27.3%, 6/22) and fibromuscular dysplasia (13.6%, 3/22). As for the target organ damage of RVH, patients had a higher prevalence of left ventricular hypertrophy (71.4%, 35/49) and retinopathy (77.8%, 21/27). CONCLUSIONS: Most RVH patients with HTN-C as the first symptoms, especially for males over 6 years old, should be assessed for RVH even if they were asymptomatic. Most asymptomatic patients with RVH already had target organ damage, and symptomatic patients even developed life-threatening complications. As preventive measures, routine monitoring of BP during children's physical examinations is advised.

The challenge to prove a rare cause of secondary arterial hypertension. A case report of a pediatric renal solitary fibrous tumor.

BACKGROUND: Childhood hypertension is getting more attention in recent years. We present a case report of a rare cause of secondary arterial hypertension in a teenage girl - a solitary fibrous tumor of the kidney. The case demonstrates that standard imaging techniques, computed tomography and magnetic resonance imaging, are not fully reliable in the diagnosis of renovascular hypertension. CASE: A 15-year old girl was admitted to the Pediatric Department because of episodes of stiffness in the limbs, accompanied by pale skin and lips, dated 4 months back. During these episodes, high blood pressure up to 160/100 mmHg was measured. A 24-hour blood pressure monitoring demonstrated arterial hypertension stage II. Renovascular hypertension was suspected, but the computed tomography examination of the abdomen showed normal-sized renal arteries. In the left kidney hilum, an intraparenchymal formation was discovered. The data presented a non-specific lesion with a wide differential diagnosis. Given the fact that the patient had been treated with an ACE-inhibitor, serum renin level could not be correctly interpreted. The lesion was removed through a laparoscopic intervention. Intraoperatively, the tumor was compressing a small intra-renal vessel - a finding that hadn`t been discovered by the previous imaging studies. The final pathologist diagnosis was: solitary fibrous tumor. During the next six months of follow-up, the maximal blood pressure values of the patient were up to 120/80 mmHg. CONCLUSIONS: Solitary fibrous tumors of the kidneys are infrequent in children. The presented case displays a rare form of initial clinical manifestation of this tumor. It is also a demonstration that standard imaging techniques are not able to get a precise visualization of the small intra-renal vessels. At the same time, the decision of whether or not to perform a more invasive procedure should be based on the clinical conditions and risks of the individual patient.

Malignant arterial hypertension in a 2-month-old girl: Etiological diagnosis and treatment.

A 2-month-old girl presented with malignant arterial hypertension revealing bilateral renal artery stenosis secondary to neurofibromatosis type 1 (NF1). Life-supporting care was initiated immediately. High-dose peripheral vasodilator therapy induced life-threatening toxicity; vascular surgery was therefore performed. Technical difficulties due to the young age and low body weight of the patient resulted in fatal bleeding. Renovascular disease is an important cause of pediatric hypertension. NF1-associated renovascular hypertension in young pediatric patients is rare, and its highly specialized management is best delivered via a multidisciplinary approach. The long-term prognosis remains poor.