Cause Of Renal Artery Stenosis Research Articles

Prevalence and predictors of renal artery stenosis in patients with coronary artery disease

Background Renal artery stenosis (RAS) is an important clinical entity that can lead to uncontrolled hypertension and progressive renal failure. The most common causes of RAS are atherosclerosis and fibromuscular dysplasia. Because the diagnosis of renovascular hypertension is established only when revascularization of a stenosed renal artery results in cure or improvement in patients hypertension, establishment of a causal relationship between RAS and hypertension continues to present a challenge. Therefore, a high index of suspicion is essential in the diagnosis of this condition. Methods Multiple tests, both invasive and noninvasive, are available as screening methods. Angiography remains the gold standard for diagnosis of RAS. Besides its value in establishing the diagnosis, it provides anatomic information regarding the site and severity of stenoses and appropriate revascularization strategies. Magnetic resonance angiography and duplex ultrasonography are the most promising and accurate noninvasive screening tests available, even in the presence of renal insufficiency. With advances in percutaneous transluminal angioplasty techniques, including renal artery stenting, many more patients are eligible for less invasive and effective revascularization strategies compared with the traditional surgical procedures. Results Revascularization of a stenosed renal artery is associated with preservation of renal function and better control of hypertension, unstable angina, and congestive heart failure. Because atherosclerotic RAS is associated with generalized atherosclerosis, aggressive risk factor modification and antiplatelet therapy are integral in the management of RAS regardless of the revascularization strategy. (Am Heart J 2002;143:559-64.)

Mid-aortic syndrome: A case report and review of the literature

Renovascular disease is an important cause of secondary hypertension in children. In contrary to the adult patients whose major cause of renal artery stenosis (RAS) is atherosclerosis, fibromuscular dysplasia is responsible for the renovascular hypertension in most children. Mid-aortic syndrome (MAS) is a rare abnormality referring to an isolated disease of the distal thoracic and abdominal aorta resulting in significant tubular narrowing with stenosis of the visceral and renal arteries. It is usually diagnosed in young adults, but may present in childhood as a challenging problem. Patients with MAS are often first detected due to refractory hypertension. Other later presentations include intermittent claudication, congestive heart failure, renal insufficiency and symptoms of hypertensive associated end-organ damage. We report a case of a 16-year-old patient with MAS who suffered from malignant arterial hypertension. A percutaneous transluminal renal angioplasty (PTRA) was first performed, however the stenosis proved resistant to dilatation and only resulted in a minimal angiographic improvement. Due to persistent hypertension, an aortorenal bypass using the saphenous vein was performed. We also reviewed the literature on PTRA and the surgical management of RAS in MAS patients, in which PTRA often carries poor results.

1273: Renovascular hypertension: Role of ultrasound and color Doppler

Renovascular hypertension (RVH) is the most common secondary form of hypertension. It is the responsible factor in almost 7% of hypertensive patients. Amongst patients with significant renal artery stenosis (RAS), about two-thirds show improvement of hypertension after revascularization. The need for a noninvasive, easily available and cheap modality for screening patients suspected to have RAS is obvious, and Doppler fulfills these requirements. The group in whom RVH should be suspected are the patients with hypertension at extremes of age, hypertension which is severe, poorly controlled, rapidly worsening and with known peripheral vascular or aortic disease. Patients of RVH could present with renal insufficiency, abdominal bruit or with unilateral small kidneys on ultrasound. Evaluation of aorta is important. The factors in intrarenal arteries to be observed are loss of early systolic peak, acceleration time and acceleration index. Visualization of Tardus-Parvus effect is more useful in diagnosis of significant RAS in day-to-day practice. The criteria used while interrogating the main renal artery are angle corrected PSV and renal artery/aorta ratio. Factors that limit evaluation of main renal artery include obesity, gas, respiratory movement, anatomical variations and operator dependency. In such patients, indirect evaluation of intrarenal arteries is most useful. Indirect evaluation of intrarenal arteries is not only technically easy, but has a high degree of sensitivity and specificity; a careful evaluation allows one to detect segmental and accessory artery stenosis as well. The talk will focus on newer applications of Doppler such as utility of Doppler in predicting success of revascularization procedures and their effectiveness. Emphasis will be placed on diagnosing restenosis. Doppler is an excellent noninvasive and cost-effective technique to follow up stent and pick up stent stenosis and occlusion. Atherosclerosis is the most common cause of RAS, but several other causes such as fibromuscular dysplasia, aortoarteritis, aneurysm and thrombosis can also cause renovascular hypertension. An alert sonologist can make an uncommon diagnosis like coarctation of aorta, interrupted aortic arch and polyarteritis nodosa. By now, we have seen almost all known causes of RVH. Doppler also plays an important role in evaluating renal arteries in transplant kidneys. Early diagnosis of even mild stenosis is important in this group of patients as a late diagnosis can result in transplant dysfunction.

Renal Artery Aneurysm Secondary to Fibromuscular Dysplasia in a Young Patient

An 8-year-old male was found on routine physical examination to have a blood pressure of 220/110. Renal angiography demonstrated bilateral renal artery stenosis and an aneurysm of the distal left renal artery with branch involvement. At operation, the left renal artery stenosis and aneurysm was repaired by ex vivo arterial reconstruction and autotransplantation of the kidney. Pathologic evaluation of the resected aneurysm confirmed the diagnosis of fibromuscular dysplasia. Fibromuscular dysplasia is the most common cause of renal artery stenosis in children over 1 year of age and can in rare cases be associated with the development of renal artery aneurysms. In complex cases of renal artery stenosis with involvement of renal artery branches, ex vivo repair and orthotopic autotransplantation is an excellent approach for surgical management.

Renovascular hypertension

Renal artery disease is the most common cause of potentially curable secondary hypertension, with atherosclerosis as the major cause of renal artery stenosis. Fibromuscular dysplasia is a less common cause of renal artery stenosis and is most frequently observed in premenopausal women. Renal artery stenosis is likely to be underappreciated and is more common in patients with other vascular disease (e.g., coronary or peripheral arterial disease). The diagnosis of renal artery stenosis requires a high clinical index of suspicion as well as an appropriate imaging strategy, with currently effective diagnostic modalities including magnetic resonance imaging, computed tomography and renal artery duplex ultrasonography. The current treatment of choice for atherosclerotic renal artery stenosis is balloon angioplasty and secondary stenting, whereas angioplasty alone is the treatment for renal artery stenosis secondary to fibromuscular dysplasia. Expected outcomes following revascularization include improved blood pressure control and possibly renal preservation. Ongoing studies will hopefully identify patient characteristics that will achieve the most benefit from percutaneous revascularization as well as the impact of percutaneous revascularization with drug-eluting stents and embolic protection devices.

Management of patients with renal artery stenosis. Reappraisal of operative treatment

Arterial hypertension is most often the first symptom of renal artery stenosis (RAS). Appropriate screening methods for the diagnostic workup of hypertension are colour-coded duplex ultrasound and captopril scintigraphy. Angiography (intraarterial digital subtraction angiography) represents the diagnostic "gold standard", which is the prerequisite for the selection of the most suitable therapeutic method. Atherosclerosis is the most common disease in elderly patients presenting with RAS. In younger patients, fibromuscular dysplasia is more frequent. Five main types with different prognosis and therapeutic indications can be classified. Rare causes of RAS are dissection, renal artery aneurysm with combined stenosis, and especially in children and adolescents middle aortic syndrome with hypoplasia of the visceral arteries. Every patient with RAS of hemodynamic relevance in the presence of hypertension should be treated, whereas therapeutic risk and benefit must be weighed up individually. Aims are the improvement of hypertension and the maintenance of renal function. Surgical techniques, which are described subsequently, are indicated in all patients who need further simultaneous treatment of the abdominal vessels (abdominal aortic aneurysm, aortoiliac or visceral artery stenosis or aneurysm, respectively). In atherosclerotic ostial stenoses, angioplasty (PTA) and open surgery (normally transaortic endarterectomy) are concurrent methods. In our experience, the long-term results of surgical reconstruction seem to be superior. Both procedures are subject to an ongoing randomized study in our department. The outcome of surgical treatment for RAS is satisfying, the operative risk especially in isolated renal artery lesions is negligible.

Mechanisms of renal structural alterations in combined hypercholesterolemia and renal artery stenosis.

Atherosclerotic renovascular disease (ARVD) aggravates renal scarring more than other causes of renal artery stenosis (RAS), but the underlying pathogenic mechanisms of this potential profibrotic effect remain unclear. We tested the hypothesis that coexistence of atherosclerosis and RAS interferes with renal tissue remodeling. Single-kidney hemodynamics and function were quantified in vivo with electron-beam computed tomography in 3 groups of pigs (n=7 each): normal pigs, pigs 12 weeks after induction of unilateral RAS (RAS group), and pigs with similar-degree RAS fed a 12-week 2% hypercholesterolemic diet (HC+RAS, simulating early ARVD). Kidneys were studied ex vivo by Western blotting and immunohistochemistry. Renal volume, renal blood flow, and glomerular filtration rate were similarly decreased in RAS and HC+RAS ischemic kidneys, accompanied by similar increased expression of profibrotic factors like transforming growth factor-beta, tissue inhibitor of metalloproteinase-1, and plasminogen activator inhibitor-1. Nevertheless, HC+RAS kidneys showed increased intrarenal fibrosis compared with RAS-only kidneys. Furthermore, expression of nuclear factor-kappaB was increased, expression of extracellular (matrix metalloproteinase-2) and intracellular (ubiquitin) protein degradation systems was decreased, and apoptosis was blunted. Diet-induced HC superimposed on RAS accelerates the development of fibrosis in the stenotic kidney by amplifying profibrotic mechanisms and disrupting tissue remodeling. These alterations might contribute to renal disease progression in ARVD and might account for the increased propensity for end-stage renal disease.

Distinct renal injury in early atherosclerosis and renovascular disease.

Atherosclerotic renovascular disease may augment deterioration of renal function and ischemic nephropathy compared with other causes of renal artery stenosis (RAS), but the underlying mechanisms remain unclear. This study was designed to test the hypothesis that concurrent early atherosclerosis and hypoperfusion might have greater early deleterious effects on the function and structure of the stenotic kidney. Regional renal hemodynamics and function at baseline and during vasoactive challenge (acetylcholine or sodium nitroprusside) were quantified in vivo in pigs by electron-beam computed tomography after a 12-week normal (n=7) or hypercholesterolemic (HC, n=7) diet, RAS (n=6), or concurrent HC and a similar degree of RAS (HC+RAS, n=7). Flash-frozen renal tissue was studied ex vivo. Basal cortical perfusion and single-kidney glomerular filtration rate (GFR) were decreased similarly in the stenotic RAS and HC+RAS kidneys, but tubular fluid reabsorption was markedly impaired only in HC+RAS. Perfusion responses to challenge were similarly blunted in the experimental groups. Stimulated GFR increased in normal, HC, and RAS (38.3+/-3.6%, 36.4+/-7.6%, and 60.4+/-9.3%, respectively, P<0.05), but not in HC+RAS (6.5+/-15.1%). These functional abnormalities in HC+RAS were accompanied by augmented perivascular, tubulointerstitial, and glomerular fibrosclerosis, inflammation, systemic and tissue oxidative stress, and tubular expression of nuclear factor-kappaB and inducible nitric oxide synthase. Early chronic HC+RAS imposes distinct detrimental effects on renal function and structure in vivo and in vitro, evident primarily in the tubular and glomerular compartments. Increased oxidative stress may be involved in the proinflammatory and progrowth changes observed in the stenotic HC+RAS kidney, which might potentially facilitate the clinically observed progression to end-stage renal disease.

Renal artery stenosis: A cardiovascular perspective

Background Renal artery stenosis (RAS) is an important clinical entity that can lead to uncontrolled hypertension and progressive renal failure. The most common causes of RAS are atherosclerosis and fibromuscular dysplasia. Because the diagnosis of renovascular hypertension is established only when revascularization of a stenosed renal artery results in cure or improvement in patients hypertension, establishment of a causal relationship between RAS and hypertension continues to present a challenge. Therefore, a high index of suspicion is essential in the diagnosis of this condition. Methods Multiple tests, both invasive and noninvasive, are available as screening methods. Angiography remains the gold standard for diagnosis of RAS. Besides its value in establishing the diagnosis, it provides anatomic information regarding the site and severity of stenoses and appropriate revascularization strategies. Magnetic resonance angiography and duplex ultrasonography are the most promising and accurate noninvasive screening tests available, even in the presence of renal insufficiency. With advances in percutaneous transluminal angioplasty techniques, including renal artery stenting, many more patients are eligible for less invasive and effective revascularization strategies compared with the traditional surgical procedures. Results Revascularization of a stenosed renal artery is associated with preservation of renal function and better control of hypertension, unstable angina, and congestive heart failure. Because atherosclerotic RAS is associated with generalized atherosclerosis, aggressive risk factor modification and antiplatelet therapy are integral in the management of RAS regardless of the revascularization strategy. (Am Heart J 2002;143:559-64.)

Polymorphisms of the renin-angiotensin system in patients with multifocal renal arterial fibromuscular dysplasia.

Fibromuscular dysplasia (FMD) is an important cause of renal artery stenosis, particularly in young females. Polymorphisms of the renin-angiotensin (RA) system have been implicated in the pathogenesis of hypertension and atherosclerotic vascular disease, and may play a role in the development of FMD. Examination of polymorphisms by PCR for angiotensin-converting enzyme (ACE) I/D, angiotensin II type 1 receptor (AT1R) A1166C and angiotensinogen (AGT) M235T and T174M was undertaken in 43 patients with typical multifocal renal arterial FMD (MF-FMD) and in 89 controls. The age of MF-FMD patients at the time of diagnosis of hypertension did not differ (38.6 + 11.1 years vs 35.5 +/- 10.3 years, P = 0.12) from controls and the proportion (95% vs 86%, P = 0.14) of females was similar. Allele frequencies did not differ significantly between groups, except that MF-FMD patients had a significantly higher frequency of the ACE I allele than control subjects (0.62 vs 0.47, P = 0.026). Since the ACE I allele is associated with lower circulating ACE levels and possibly lower tissue levels of angiotensin II (Ang II), and since Ang II modulates vascular smooth muscle cell growth and synthetic activity, the I allele might predispose to defective remodelling of the arterial media, and thus to the development of MF-FMD. This contrasts with atherosclerotic renal artery stenosis, coronary stent restenosis and carotid intimal thickening, which are diseases affecting the arterial intima, and which are associated with increased frequency of the D allele.

Fibromuscular dysplasia of the renal artery: Management and outcome

Renovascular hypertension may be caused by atherosclerotic disease or less commonly by fibromuscular dysplasia (FMD) of the renal arteries. Fibromuscular dysplasia is the commonest cause of renal artery stenosis in the younger age group and affects women predominantly. A review of our clinical database identified all patients with renovascular hypertension. All relevant clinical, biochemical and radiological findings on those with FMD were noted. The outcome of percutaneous transluminal renal angioplasty (PTRA) or reconstructive surgery was evaluated. Eight out of 62 (13%) patients with hypertension secondary to renovascular disease had FMD (all female; bilateral in four; mean age at diagnosis 37.6 years; age range 12–70 years). The mean duration of hypertension before the diagnosis of FMD was 3.3 years (range 3 months–10 years). A renal artery bruit was detected in five, hypertensive retinopathy in three and one had mild renal insufficiency. Twelve PTRAs were attempted on 10 stenotic lesions in six women. This cured the hypertension in three, while the other three have required less antihypertensive therapy. Percutaneous transluminal renal angioplasty was complicated by a trivial renal artery dissection in one, and a small upper pole infarction in another. One patient required a repeat PTRA. The other two women presented before the availability of PTRA and had successful reconstructive surgery. Fibromuscular dysplasia was the cause of hypertension in eight out of 62 (13%) patients with renovascular hypertension. Percutaneous transluminal renal angioplasty has shown encouraging results with a low complication rate. If technically feasible, PTRA should be attempted on all patients with FMD of the renal artery.

Fibromuscular dysplasia of the renal artery: Management and outcome

SUMMARY: Renovascular hypertension may be caused by atherosclerotic disease or less commonly by fibromuscular dysplasia (FMD) of the renal arteries. Fibromuscular dysplasia is the commonest cause of renal artery stenosis in the younger age group and affects women predominantly. A review of our clinical database identified all patients with renovascular hypertension. All relevant clinical, biochemical and radiological findings on those with FMD were noted. the outcome of percutaneous transluminal renal angioplasty (PTRA) or reconstructive surgery was evaluated. Eight out of 62 (13%) patients with hypertension secondary to renovascular disease had FMD (all female; bilateral in four; mean age at diagnosis 37.6 years; age range 12–70 years). the mean duration of hypertension before the diagnosis of FMD was 3.3 years (range 3 months‐10 years). A renal artery bruit was detected in five, hypertensive retinopathy in three and one had mild renal insufficiency. Twelve PTRAs were attempted on 10 stenotic lesions in six women. This cured the hypertension in three, while the other three have required less antihypertensive therapy. Percutaneous transluminal renal angioplasty was complicated by a trivial renal artery dissection in one, and a small upper pole infarction in another. One patient required a repeat PTRA. the other two women presented before the availability of PTRA and had successful reconstructive surgery. Fibromuscular dysplasia was the cause of hypertension in eight out of 62 (13%) patients with renovascular hypertension. Percutaneous transluminal renal angioplasty has shown encouraging results with a low complication rate. If technically feasible, PTRA should be attempted on all patients with FMD of the renal artery.

Stenting in Renal Artery Stenosis

Background：Renal artery stenosis(RAS is a major cause of renovascular hypertension and reduced renal function due to ischemic atrophy of kidney. There are several methods to treat the RAS, including are surgery, percutaneous transluminal renal angioplasty, and medical treatment. The purpose of this study is to evaluate the usefulness, safety, and efficacy of percutaneous transluminal stent deployment in RAS. Method：From January 1995 to July 1996, 17 patients underwent renal stent implantation due to renal artery stenosis(11 male, 6 female. The mean age was 49 years old, one patient had both renal artery stenosis and total lesions were 18. The causes of renal artery stenosis were atherosclerosis in 12, fibromuscular dysplasia in 2, Takayasu’ s disease in 2, and autoimmune disease(Bechet’s in one case. Renal artery stenting was performed via femoral artery in 12 lesions and brachial artery in 6 lesions. Follow up was performed by renogram, renal angiogram, and clinical examination. Result：The degree of renal artery stenosis was 83%(70-95%. The lesion sites were 12 ostial and 6 non-ostial lesions. The used renal stents were Palmaz-biliary stent in 17 lesions and Micro-II stent in one lesions. All stents were implanted successfully and there was no residual stenosis in all patients except one case showed 20% residual stenosis due to huge renal artery size. The transstenotic pressure gradients after renal artery stenting was decreased markedly from 74mmHg to 2mmHg. There was no serious complications such as a death, emergency surgery, or nephrectomy. There were two minor complications which were one case of pyelonephritis and one case of inguinal hematoma. After stenting, blood pressure was decreased partially in 13 patients and completely in 2 cases. Conclusion：Renal artery stenting appears to be safe and feasible and the alternative treatment modality to surgery for renal artery stenosis.

Role of captopril renography in the diagnosis of renovascular hypertension

Eighty-six hypertensive patients with clinical suspicion of renovascular hypertension (RVH) were evaluated by captopril renal scintigraphy (CRS) and intra-arterial digital subtraction angiography (IADSA) to determine the usefulness of CRS in the diagnosis of RVH and to predict the outcome of revascularization procedures. Technetium 99m-diethylenetriaminepentaacetic acid (DTPA) renal scintigraphy was performed on 2 consecutive days before and after captopril administration. Captopril renal scintigraphy was considered positive if there were changes in the time activity curve according to the criteria specified by the American Society of Hypertension working group. Captopril renal scintigraphy data were compared with presence or absence of anatomic renal artery stenosis (RAS). Of 86 hypertensive patients investigated, 45 had RAS. Aortoarteritis was the cause of RAS in 40 (89%) patients. Revescularization was done in 25 patients, and response to revascularization was compared with that of captopril renography. Compared with IADSA, CRS showed a sensitivity of 82.8% and a specificity of 98.2%. Fourteen patients had bilateral RAS on IADSA. In these patients, CRS was suggestive of bilateral disease in seven patients, unilateral in four, and negative in three. Comparison of CRS with the results of revascularization showed a sensitivity and specificity in detecting curable RAS (RVH) of 95% and 100%, respectively (positive predictive value, 100%; negative predictive value, 85%). In conclusion, we found CRS to be useful in the diagnosis of RVH due to aortoarteritis.

Two-year clinical follow-up of children and adolescents after percutaneous transluminal angioplasty for renovascular hypertension.

Two percent of children have hypertension. For those younger than 10 years of age, there is a high probability that hypertension is secondary. The purpose of this study was to evaluate the merits of percutaneous transluminal angioplasty (PTA) in the treatment of childhood renovascular hypertension (RVH) in light of the results previously obtained by the authors and to evaluate their stability at 2-year follow-up. The positive response of peripheral renin plasma levels to a single dose of captopril was used as a criterion for selecting 36 patients between 4 and 15 years of age with renovascular hypertension. All underwent angiography; in most patients, PTA was performed in the same session. A 2-year follow-up study was conducted. In the 36 patients considered for RVH screening, PTA was successful in 34 of 36 patients (94%). Four of these patients had neurofibromatosis. The high success rate was confirmed in the 2-year follow-up study: 34 patients continue to be normotensive. Percutaneous transluminal angioplasty treatment of pediatric patients with hypertension has proved to be an effective and valuable method when the cause of renal artery stenosis is fibromuscular dysplasia, and the long-term results were sufficient to suggest the use of this technique in patients with neurofibromatosis as well.

Renal artery stenosis in children

In a large paediatric renal unit over the last 14 years, 19 children (10 male and 9 female, aged 1 week to 16 years, mean 7 years) with renal artery stenosis (RAS) were evaluated. Transplant RAS cases were not included. All 19 children were hypertensive. In 10 this was an incidental finding. Based on clinical findings and arteriography, the causes of RAS included a middle aortic syndrome (MAS) (n = 5), neurofibromatosis (n = 3), William's syndrome (n = 3), fibromuscular hyperplasia (FMH) (n = 4), idiopathic RAS (n = 2) and isolated branch artery stenosis (n = 2). Previous studies have suggested FMH is the commonest cause of RAS in the paediatric population. In our study the largest subgroup are MAS/William's syndrome children, in whom the angiographic appearances were indistinguishable. Where possible, management, both surgical and radiological, and eventual outcomes have been described.

Renovascular reconstruction: Factors affecting long-term prognosis in 919 patients followed up to 31 years

During the 31-year period from May 3, 1955, to May 12, 1986, renovascular reconstructions were performed on 919 patients. The mean age of the 529 men was 54 ± 0.58 (SE) years and, of the 390 women, 48 ± 0.7 years. Mean preoperative diastolic blood pressure was 110 ± 0.6 mm Hg. The most common causes of renal artery stenosis were atherosclerosis in 647 patients, fibromuscular disease in 161 patients, and renal artery aneurysm in 51 patients. In the remaining 60 patients, other causes were present, including kinks and fibrous bands. The most common surgical procedures were Dacron bypass graft (780 arteries) and endarterectomy with or without a patch graft (329 arteries). Four hundred sixty-nine patients had associated operations, the most common of which were abdominal aortic aneurysmectomy in 231 and aortoiliofemoral reconstruction in 141 patients. The perioperative mortality rate was 5.5% (51 of 919 overall); for renal procedures alone, it was 1.7% (8 of 450) and for combined surgical procedures, 9.2% (43 of 469). The overall graft patency rate at a follow-up of 18.8 ± 1.9 months was 88.6% (381 of 430) and at a second follow-up of 50 ± 4.3 months, 86.7% (111 of 128). Analysis of long-term blood pressure response and factors affecting late survival indicated that patients with preoperative diastolic pressures of >100 mm Hg and renal artery stenosis of >70% had the best blood pressure responses and that male sex, increasing age, bilateral renal stenosis, and associated vascular operations lowered the survival rate whereas fibromuscular disease enhanced the duration of survival. Thus, renal artery reconstruction resulted in sustained good long-term relief of hypertension and preservation of renal function in most patients. Some subgroups of younger patients had better survival rates, but this was not true of the subgroups of the elderly.

Cardiac structure and function in renovascular hypertension produced by unilateral and bilateral renal artery stenosis

To evaluate cardiovascular status in human renovascular hypertension, quantitative echocardiographic findings were compared in 42 patients with arteriographically documented renovascular hypertension and 46 age- and sex-matched patients with essential hypertension. Left ventricular (LV) fractional shortening, a measure of systolic performance at rest, was subnormal (less than 26%) in 8 of 42 renovascular hypertensive patients (19%), 0 of 42 essential hypertensive patients (p < 0.005) and 1 of 79 normal subjects (1%) (p < 0.005). Fractional shortening was equally reduced in patients with arteriosclerotic and nonarteriosclerotic causes of renal artery stenosis (32 ± 9% vs 32 ± 6%, both p < 0.025 compared with 36 ± 5% in patients with essential hypertension). The depressed function in renovascular hypertension appeared to be a result of greater LV dilation (p < 0.02) and septal but not LV free wall hypertrophy (p < 0.01) that failed to offset the pressure load, allowing end-systolic stress, a measure of myocardial afterload, to increase to abnormal levels (101 ± 47 × 10 3 dynes/ cm 2, p < 0.001 vs 68 ± 19 in essential hypertension). These data indicate that human renovascular hypertension is associated with more adverse cardiac involvement than essential hypertension of similar severity. In addition, the 14 patients with bilateral renovascular stenosis had a higher cardiac index (3.9 ± 1.1 liters/min/m 2) than the 28 with unilateral stenosis (3.2 ± 1.1. liters/min/m 2, p < 0.05). This result supports the proposition that bilateral renovascular disease is analogous to 1-clip 1-kidney experimental renovascular hypertension, while unilateral renovascular disease resembles the 1-clip 2-kidney model. Volume overload characterizes the former and is absent in the presence of a normal contralateral kidney.

Surgical treatment of renovascular hypertension in the elderly patient.

ABSTRACT. There have been many reasons for hesitating when faced with the decision whether or not to operate upon a renal artery stenosis in an aged person. Arteriosclerotic disease carries a poorer prognosis than does fibromuscular dysplasia, and in old persons arteriosclerosis is the usual cause of renal artery stenosis, and is likely to be generalized. In this study of 24 patients above 60 years of age with renovascular disease, 11 were operated upon; 9 because of renovascular hypertension and 2 with the main aim of arresting the deterioration of renal function. The selection of candidates was mainly determined by the renin secretion pattern. After operation for renovascular hypertension, 67% of the patients improved. In these patients renal function remained stable or recovered. Of the two patients operated upon because of decreasing renal function, one died postoperatively and the other suffered from technical complications resulting in a further impairment of renal function without any beneficial effect on the high blood pressure. Of the 13 patients not operated upon, 4 were clearly renin‐positive and would have been candidates for surgery had it not been for complicating factors. Three of these patients died of coronary disease within one year of the investigation. The results of our and other studies, together reviewing the fate of 56 patients above 60 years of age operated upon for renovascular hypertension, do not indicate that old age per se should be considered a contraindication to surgery when proper attention is paid to co‐existing risk factors. The majority of patients operated upon for renovascular hypertension will benefit from the surgical treatment.

Renal Perfusion Preservation Without Cannulation

Cadaver kidneys were preserved by a technique that uses hypothermic pulsatile perfusion without cannulation of the renal arteries. This avoids the mechanical trauma that is inevitably associated with cannulation and preserves a maximum of untraumatized arterial tissue. Cannulation injury is thus eliminated as a potential cause of renal artery stenosis. Revascularization is simplified, especially when multiple renal arteries are attached to a cuff of aorta.