Prognostic significance of intrarenal resistance indices in patients with renal artery interventions: a preliminary duplex sonographic study

No non-invasive test can predict the clinical outcome of renal revascularization procedures. Because duplex sonographic measurements of intrarenal flow patterns reflect the resistance to flow within the kidney, the prognostic value of the cortical end-diastolic to peak systolic (d/s) velocity ratio was investigated in patients undergoing intervention for renal artery stenosis. The clinical and duplex sonographic data on 32 patients with 35 interventions (30 percutaneous transluminal angioplasties and five operations) on 42 renal artery sides were analysed. Twenty-three patients had atherosclerotic renal artery stenosis and nine patients had fibromuscular dysplasia resulting in ≥60% renal artery stenosis. Measurements of the renal to aortic velocity ratio and cortical d/s ratio were performed before and after intervention. In the atherosclerotic patients, three interventions were clinically and technically successful, eight were technically successful but clinical failures, and 14 were clinically and technically unsuccessful. In the fibromuscular dysplasia patients, eight interventions were clinically and technically successful, and two were clinically and technically unsuccessful. The difference between the corresponding d/s ratios for atherosclerotic and fibromuscular dysplasia sides was significant on both the treated and not-treated sides (P < 0.02, two-tailed unpaired t-test). None of the 11 clinically successful procedures had a d/s ratio below 0.3, compared with seven values below 0.3 in the 24 clinically unsuccessful interventions (P = 0.05, one-tailed Fisher's exact test). It is concluded that: (1), a d/s ratio below 0.3 correlates with clinical failure in subsequent treatment of hypertension by renal revascularization, while a value above 0.3 has no prognostic significance; (2), despite technical success, not all atherosclerotic patients have clinical success from renal artery interventions; (3), in fibromuscular dysplasia patients, all clinical failures of renal artery interventions are associated with technical failures; and (4), the difference in d/s ratio between atherosclerotic and fibromuscular dysplasia patients may be a consequence of the more advanced age, longer duration of hypertension and additional risk factors in atherosclerotic patients.     

Treatment of renal artery fibromuscular dysplasia with balloon angioplasty: a prospective follow-up study.

OBJECTIVES: to assess restenosis rates and blood pressure response after percutaneous transluminal renal angioplasty (PTRA) in patients treated for fibromuscular dysplastic renal artery stenosis. METHODS: a prospective 12-month follow-up study of 27 patients with 31 treated renal artery stenosis. Follow-up assessment included colour-coded duplex sonography (CCD) of renal arteries, monitoring of blood pressure, antihypertensive medication, and creatinine measurements before discharge and at 3, 6, and 12 months. Primary end point was defined as a haemodynamically significant restenosis >60% assessed by CCD. RESULTS: there was a cumulative 23% restenosis rate at 12 months. Arterial hypertension was cured or improved in 93% of patients immediately after the intervention and remained cured/improved in 74% of patients at 12 months of follow-up. Renal failure present in five patients before PTRA stabilised or improved in all patients. CONCLUSION: although restenosis rate after PTRA in fibromuscular dysplasia is as high as in non-ostial atherosclerotic lesions, there remains a considerable higher therapeutic effect. Profound pressure response and recurrent arterial hypertension with restenosis support the high probability of a renovascular origin of arterial hypertension in this young and otherwise healthy population compared to patients with atherosclerotic renal artery lesions.     

Operative balloon angioplasty in the treatment of internal carotid artery fibromuscular dysplasia

Seven patients with symptomatic fibromuscular dysplasia have had eight internal carotid arteries treated by operative balloon dilatation. This technique is described in detail and provides three distinct advantages over conventional graduated intraluminal dilatation--atraumatic passage of the catheter through the affected vessel with fluoroscopic guidance; precise dilatation of the involved segment of the internal carotid artery; and the application of a radial force against the arterial wall rather than a longitudinal shear force, thereby making intimal damage less likely. There were no treatment complications in this group of patients. This technique of balloon angioplasty is compared with the results of treatment in eight patients with fibromuscular dysplasia of the internal carotid artery, who had percutaneous transfemoral angioplasty. Long-term follow-up revealed the resolution of symptoms in all patients.     

Clinical and duplex ultrasound follow-up after balloon angioplasty for atherosclerotic renal artery stenosis.

The purpose of this study was to investigate changes in blood pressure and renal function after percutaneous renal artery balloon angioplasty in hypertensive patients with atherosclerotic renal artery stenosis. Renal artery lesions were assessed by duplex ultrasound before and after renal artery balloon angioplasty. Renal arteries were classified as normal, < 60% stenosis, > or =60% stenosis, and occluded according to previously validated duplex criteria. Data regarding risk factors for atherosclerosis and years of hypertension were collected. Systolic and diastolic blood pressure, creatinine, and number of medications were obtained before and after intervention. The immediate technical outcome of renal artery angioplasty was classified based on the arteriographic result as follows: success (residual stenosis < or =30%), partial success (residual stenosis 31-50%), or unsuccessful (residual stenosis > 50%). For bilateral procedures, success required both renal arteries to be classified as technical successes; a technical success on one side only was classified as partial success. The blood pressure response to intervention was classified as follows: cure (diastolic blood pressure < or =95 mm Hg on no medications), improved (control of blood pressure with a significant reduction in number of medications or control of previously elevated blood pressure without a change in medications), or failed (all other responses). The study group included 28 patients (14 men, 14 women) with a mean age of 65 years. The preintervention and the first postintervention evaluations occurred within 180 days of the procedure. All patients were hypertensive, and all except one were under medical treatment. Mean duration of hypertension was 9.1 +/-8.8 years. There were 38 interventional procedures (28 unilateral, 10 bilateral) involving 41 renal arteries; seven arteries had two procedures done. Before angioplasty, all renal arteries had lesions of > or =60% diameter reduction by duplex scanning. Endovascular stents were deployed following angioplasty in 14 (34%) of the procedures. The technical result was classified as a success in 24 (63%), a partial success in 12 (32%) of the procedures, and two procedures (5%) were classed as technical failures. There were statistically significant reductions in blood pressure following successful and partially successful procedures, but cure of hypertension was achieved in only 11% of cases. There were no significant changes in creatinine in any of the technical result groups. Of the 38 renal arteries evaluated with duplex ultrasound following intervention, 39% were found to have stenosis of > or =0% involving a treated renal artery, including one postintervention occlusion. Cure of hypertension was rare in this patient population with atherosclerotic renal artery stenosis. More than one third of the treated renal arteries showed > or =0% lesions recurring after the procedure. Thirteen percent of those with technical success and 17% of those with partial technical success had creatinine improvement of at least 20% over the baseline value. Significant clinical and anatomic improvement were relatively uncommon following balloon angioplasty in this series of patients.     

Rapid Progression of Native Renal Artery Fibromuscular Dysplasia Following Kidney Donation

Fibromuscular dysplasia is the second commonest anatomical abnormality apart from multiple renal arteries in the potential live donors. Pretransplant evaluation of the donors may include an angiography to evaluate the renal arteries, and failure to recognize renal arterial stenosis, particularly fibromuscular dysplasia, by noninvasive methods may eventually lead to hypertension and ischemic renal failure. We report a case of fibromuscular dysplasia that was undetected by computed tomographic angiography prior to donation. One year after kidney donation, it rapidly progressed to severe symptomatic stenosis with hypertension and acute renal failure. Following renal artery angioplasty, her blood pressure normalized over a period of 2 weeks without any need for antihypertensive medications and the serum creatinine returned to her baseline. The acceptability of renal donors with fibromuscular dysplasia depends on the age, race and the availability of the other suitable donors. Mild fibromuscular dysplasia in a normotensive potential renal donor cannot be considered a benign condition. Such donors need regular follow-up postdonation for timely detection and treatment.     

Follow-up of renal artery stenosis by duplex ultrasound

We have previously shown that duplex ultrasound is an accurate method of diagnosing renal artery stenosis (93% accuracy compared with angiography in the diagnosis of less than 60% stenosis, 60% to 99% stenosis, or occlusion). With this method we have now serially observed 35 renal arteries with 60% to 99% renal artery stenosis in 27 patients. Nineteen stenotic renal arteries in 15 patients were observed without intervention. There was a significant decrease in kidney size (mean difference - 1.0 cm; p less than 0.01; mean follow-up 13 months) but all 19 renal arteries remained patent. Percutaneous transluminal angioplasty (PTA) was performed in five patients (six renal arteries) for renovascular hypertension. Renal duplex scanning documented relief of renal artery stenosis in two patients whose hypertension improved after PTA and confirmed residual 60% to 99% renal artery stenosis in three patients whose hypertension did not improve after PTA (mean follow-up 6.5 months). Aortorenal bypass was performed for 10 stenotic renal arteries in seven patients. At a mean follow-up of 9 months duplex ultrasound documented eight patent and two occluded aortorenal bypass grafts. Duplex ultrasound is useful both for defining the natural history of untreated renal artery stenosis and assessing the results of renal artery angioplasty or bypass.     

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.     

Surgical renal artery reconstruction after percutaneous transluminal angioplasty

Percutaneous transluminal renal angioplasty (PTRA) is a controversial treatment for renal artery stenosis. This article discusses whether or not a prior attempt at PTRA compromises a subsequent elective or emergent surgical revascularization. Thirteen patients had surgical renal artery reconstruction after one or more PTRAs. Eight of the patients were treated because of atherosclerotic renal artery disease whereas five had a form of fibromuscular dysplasia. Five patients had renal artery injury directly related to the angioplasty. Four of these kidneys were saved. Eight patients were treated from 6 to 920 days after PTRA because of recurrent stenosis or occlusion of the renal artery. Only one of these kidneys was lost, an attempt at revascularization of a small kidney that failed to resume function. A prior attempt at PTRA did not compromise the ability of subsequent surgical revascularization to ameliorate hypertension. We conclude that surgical renal revascularization is not made less likely to succeed by a previous attempt at PTRA; even if the renal artery is thrombosed or perforated during the procedure, a reasonable chance of renal salvage is obtained by immediate surgical revascularization.     

Selection of patients with lower limb arterial occlusive disease for endovascular treatment of the iliac arteries with duplex scanning

The aim of this study was to evaluate the role of duplex scanning in selection of patients with lower limb arterial occlusive disease for endovascular treatment of the iliac arteries. From January 1995 through May 2000, 183 patients having chronic lower limb arterial insufficiency who underwent duplex scanning of the lower extremity arteries with available aortoiliac scans within 3 months before conventional aortoiliac diagnostic angiography and/or endovascular intervention of the iliac arteries were studied retrospectively. The findings obtained from duplex scanning and angiography were analyzed in a blinded manner by 2 investigators. Limbs having category 1, 2, and 3 lesions according to duplex scan findings were interpreted as being suitable for endovascular intervention. The comparison between duplex scan findings and angiography was analyzed by the third investigator. During 93 percutaneous transluminal angioplasty (PTA) procedures, 133 arterial segments, common or external iliac, were dilated with stent placement in 70. Bilateral interventions were performed in 25 cases, and of 68 unilateral interventions, 57 were at only 1 arterial segment. The accuracy, sensitivity, specificity, and negative and positive predictive values of duplex scanning to appropriately categorize the iliac artery lesions into suitable or unsuitable for endovascular intervention were 90%, 95%, 83%, 90%, and 92%, respectively when the inconclusive duplex scans were excluded (11%). In 6 patients with lesions suitable for PTA according to duplex scanning and angiography, PTA was not performed owing to clinical reasons. The accuracy of duplex scanning in predicting the performance of endovascular intervention was 88%. It is concluded that iliac artery endovascular procedures in limbs with chronic occlusive disease can be reliably planned according to duplex scan findings.     

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.     

Clinical spectrum of symptomatic external iliac fibromuscular dysplasia

External iliac fibromuscular dysplasia is a rare and usually asymptomatic disorder. We report eight symptomatic patients seen over a 15-year period and review pathophysiologic mechanisms accounting for the three following distinct lower extremity ischemic sequelae: (1) Emboli--episodic focal digital ischemia (blue toe) was seen in three patients. Resection and primary anastomosis of focal iliac ulcerative fibromuscular dysplasia (one patient) or resection and replacement (two patients) removed the embolic source and relieved the symptoms. (2) Chronic ischemia--gradual onset of full leg claudication in four patients was treated by operative graduated intraluminal dilation in three patients and prosthetic bypass in one. Arteriography subsequently showed a remodeled lumen in the three patients who underwent dilation. (3) Dissection--acute onset leg ischemia resulted from presumed dissection of the external iliac segment. After 4 months of conservative management of antiplatelet agents and exercise, symptoms resolved completely, and arteriogram showed spontaneous restoration of a normal lumen in the dissected segment. The clinical presentation of fibromuscular dysplasia may mimic other arterial processes such as atherosclerosis. Diagnosis is made only by arteriography with specific magnification views of the external iliac arteries and careful surveillance of the renal arteries. Appropriate treatment should be tailored to the clinical presenting symptom. For microembolic disease, resection and replacement are required. For chronic ischemia, intraluminal dilation is generally sufficient and durable and has proved to be a simpler and acceptable alternative to replacement or bypass. In acute dissection, surgical intervention may be deferred if the limb is viable to allow spontaneous healing and remodeling. Persistent symptoms may be the only indication for intervention in this ischemic manifestation of external iliac fibromuscular dysplasia.     

Bilateral brachial artery fibromuscular dysplasia

Fibromuscular dysplasia is a nonatherosclerotic, noninflammatory vascular disease that usually involves medium- and small-sized arteries. It is most commonly observed in the renal, carotid, and intracerebral arteries, although it has been reported in other arterial beds. The most common form is characterized by medial fibrosis, with or without smooth muscle cell hyperplasia, which can result in luminal narrowing and turbulent flow. There is often a secondary aneurysmal degeneration of the artery, which may or may not be associated with thrombosis or obstruction of flow. This accounts for the typical string-of-beads appearance seen on arteriography. We describe a patient who presented with ischemia of the right hand secondary to fibromuscular dysplasia of the brachial artery. Subsequent studies also demonstrated fibromuscular dysplasia in the other brachial artery as well as mild involvement of the right renal artery. The patient was treated on the symptomatic side with dilatation of proximal lesions, resection of the thrombosed segment, and reconstruction with a reversed saphenous vein graft. Distal pulses were fully restored postoperatively. Pathologic examination confirmed the arteriographic and clinical diagnosis of fibromuscular dysplasia. The salient features of this case are reviewed in addition to the other cases reported in the literature.     

Cutting balloon angioplasty of resistant renal artery stenosis caused by fibromuscular dysplasia

Balloon angioplasty is an established intervention to treat renovascular hypertension. Conventional balloon angioplasty is usually effective in cases of renovascular hypertension caused by fibromuscular dysplasia. In the present report, we describe two cases of renovascular hypertension caused by fibromuscular dysplasia in which stenotic lesions were resistant to conventional balloon angioplasty but were successfully managed by a cutting balloon. After cutting balloon angioplasty, systemic blood pressure was normalized in both patients, without the use of antihypertensive agents. Angioplasty by using a cutting balloon is a new therapeutic choice against renal artery stenosis that is resistant to dilation by a conventional balloon.     

Surgical treatment of renal artery dissection in 25 patients: indications and results

OBJECTIVE: Results of surgical revascularization in 25 patients with renal artery dissection (RAD) over 14 years, with mean follow-up of 55.3 months (range, 10-111 months), were analyzed. Indications for surgery were renovascular hypertension and preservation or improvement of kidney function. PATIENTS AND METHODS: Two patients (both 20 years of age) underwent emergency surgery after severe trauma; 23 patients (mean age, 41 years) underwent elective surgery in a chronic stage of disease. Preoperative, postoperative, and follow-up examinations included duplex ultrasound scanning, determination of serum creatinine and urea concentrations, and evaluation of blood pressure control. All long-term patients underwent digital subtraction angiography preoperatively and postoperatively. All histologic specimens of resected renal arteries were re-evaluated by two independent pathologists. RESULTS: Histologic re-evaluation confirmed the traumatic origin in 2 patients who underwent emergency surgery and 1 who underwent elective surgery. Renal artery dissection developed spontaneously, with no histologic signs of trauma or fibromuscular dysplasia, in 22 patients. In 17 revascularized kidneys (61%) a kidney infarction had already developed preoperatively, and the kidneys were diminished in size or function. Results of revascularization and improvement of hypertension depended on preoperative extent of renal infarction. Hypertension resolved or improved in 86% of patients without preoperative kidney damage, but in only 38% with preoperatively damaged kidneys. Kidney function was preserved in 23 of 28 revascularized kidneys (82%). During follow-up, late renal artery occlusion developed in 3 kidneys. CONCLUSIONS: Renal artery dissection can be effectively treated with surgical revascularization. Primary nephrectomy should be considered only in patients with a large ischemic kidney infarction, with significant deterioration of kidney function, to effectively cure or improve severe renovascular hypertension.     

Multivisceral Fibromuscular Dysplasia in Childhood: Case Report and Review of the Literature

We report here a 9-year-old girl with fibromuscular dysplasia of many muscular arteries including both renal and internal carotid arteries, the celiac artery, superior mesenteric artery, and one external carotid artery. She suffered from severe renovascular hypertension with beginning secondary cardiac decompensation, typical angina abdominalis, and neurological signs, including severe headaches and hemianopsia. Surgery was performed for all major vessels and the outcome is good 2.5 years after the operation. The clinical presentation, differential diagnosis, and treatment options of fibromuscular dysplasia in childhood are discussed and the literature is reviewed.     

The role of arterial reconstruction in spontaneous renal artery dissection

Spontaneous renal artery dissection is an uncommon cause of renovascular hypertension, usually associated with fibromuscular dysplasia. Among reported nonautopsy cases (N = 80), arterial reconstruction has seldom been attempted (N = 21) and the outcome has frequently been poor (48% clinical failure rate). This is attributed in part to the frequent involvement of renal artery branches by the dissection. Furthermore, the report of spontaneous reversion to normotension among patients treated medically has also clouded the role of surgery in this disease. Since progress in the technique of renal artery repair now allows successful treatment of anatomically complex lesions, we reviewed our experience with arterial reconstruction in the management of spontaneous renal artery dissection to determine the frequency of and factors correlating with cure after operative repair. Ten patients (eight men, two women; mean age, 39.3 +/- 5.9 years) were admitted with severe hypertension (10/10), often associated with neurologic symptoms, hematuria, or flank pain (8/10). Serum creatinine was elevated in only two patients. Angiography demonstrated changes consistent with fibromuscular dysplasia in 7 of 10 patients and evidence of dissection in 6 of 10. Bilateral disease was present in three patients. Only five patients had a single renal artery on the involved side. The dissection extended into the primary branches in 8 of 10 patients and involved both renal arteries in four of the five patients with two arteries. Histologic study confirmed fibromuscular dysplasia in six and intramural dissection in all operative specimens. Five patients underwent revascularization (in one case requiring the ex vivo technique), with use of hypogastric artery as a conduit in four of five or resection and primary reanastomosis in one of five. Three patients became normotensive, and two returned to their previous level of blood pressure control. Follow-up averaged 14.5 years. Two patients underwent nephrectomy after exploration demonstrated nonreconstructible vessels, and two underwent nephrectomy when intraoperative assessment of the kidney showed that revascularization had failed to adequately reverse extensive renal ischemia. After a mean follow-up of 14.6 years these patients remain normotensive, although two require antihypertensive medications. One patient was treated medically and is currently hypertensive off all medications. Nine of 10 patients have maintained a normal serum creatinine during follow-up. We conclude that renal revascularization is frequently successful in spontaneous renal artery dissection (five of seven, 71.4%) and results in sustained relief of hypertension with maximal conservation of renal tissue. This is important because of the young age at onset and the not infrequent occurrence of bilateral fibromuscular dysplasia, and even of dissection.(ABSTRACT TRUNCATED AT 400 WORDS)     

Percutaneous transluminal angioplasty for renovascular hypertension in children

Percutaneous transluminal angioplasty (PTA) has been developed over the past 8 years as an alternative to reconstructive surgery for renovascular hypertension. We report three cases and review the use of PTA in children with renal artery stenosis. At least 37 cases of PTA have been reported in patients whose ages ranged from 1.3 to 17 years (mean 10 years). Of these, 10 had fibromuscular dysplasia; 13 unspecified unilateral renal artery stenosis; 4 bilateral stenosis; 4 neurofibromatosis; 4 renal transplant; 1 atherosclerosis; and 1 postsurgical stenosis. Nine of 10 patients with fibromuscular dysplasia were cured and 3 of 4 with renal transplant arterial stenosis were cured or improved. There were 11 failures of PTA, including all 4 patients with neurofibromatosis and 1 with transplant arterial stenosis. We conclude that PTA is the treatment of choice for children with hypertension due to fibromuscular dysplasia and should be attempted for stenosis of the transplanted renal artery. Other lesions resulting in renal artery stenosis may not be as amenable to dilation and should be considered on an individual basis.R. L. Chevalier is an Established Investigator of the American Heart Association     

Fibromuscular dysplasia of the brachial artery: a case report and review of the literature.

Fibromuscular dysplasia is a nonatherosclerotic, noninflammatory vascular disease that involves primarily medium-sized and small arteries. Fibromuscular dysplasia is characterized by medical fibrosis with or without smooth muscle cell hyperplasia and may produce luminal impingement with severe turbulence. Secondary aneurysmal deformity with or without thrombosis may also contribute to the obstruction. Fibromuscular dysplasia most commonly involves the renal and carotid arteries, with upper-extremity disease rarely reported. This case report describes a patient with digital embolization from brachial artery fibromuscular dysplasia. Angiography demonstrated significant narrowing and irregularity with a characteristic "string-of-beads" appearance of the right midbrachial artery. The abnormal segment was resected and reconstructed with a reversed saphenous vein graft. Histologic studies revealed disruption of the internal elastic lamina and disorientation of the hyperplastic medial smooth muscle cells characteristic of fibromuscular dysplasia.     

Endovascular management of spontaneous carotid artery dissection

OBJECTIVE: Despite medical therapy, a subset of patients with spontaneous carotid artery dissection (SCD) experience recurrent or progressive symptoms. In this study, we assessed the safety and efficacy of endovascular stent angioplasty in the treatment of SCD. METHODS: Seven consecutive patients with SCD underwent endovascular stent angioplasty of a total of 12 vessels. Indications included the presence of a large or enlarging pseudoaneurysm, a contraindication to anticoagulation, failure of anticoagulation, and compromised cerebral blood flow. RESULTS: Five patients had fibromuscular dysplasia. All patients tolerated the procedure well, with no adverse clinical events. All patients showed symptomatic improvement on clinical follow-up except for one patient, who had hemorrhagic conversion of a pre-existing large ischemic stroke 13 days after intervention; he made an eventual recovery to baseline. All stents have remained patent on radiologic follow-up. CONCLUSIONS: This study provides additional evidence that endovascular stent angioplasty is a safe and effective treatment for SCD in patients for whom medical treatment is not adequate.     

Role of duplex scanning for the detection of atherosclerotic renal artery disease

To assess the accuracy of renal artery duplex scanning for the purpose of diagnosing atherosclerotic renal artery stenosis, we compared the findings of renal arteriograms to the results of duplex scanning in 41 patients. Using an increase of renal artery peak systolic flow velocity of greater than 180 cm/sec, duplex scanning was able to discriminate normal from diseased renal arteries with a sensitivity of 95% and a specificity of 90%. Using the principle that blood flow velocity across a stenosis is roughly proportional to the degree of stenosis, it appeared that a ratio of the peak velocity in the renal artery to the aorta (RAR) of greater 3.5 predicted a greater than 60% diameter reduction of that renal artery, which is felt to be a significant stenosis. Forty-eight vessels were classified as having a greater than 60% diameter reduction by arteriography. Using the RAR of greater than 3.5, duplex scanning agreed in 44 renal arteries (sensitivity 92%). In the 26 renal arteries where arteriography showed a less than 60% diameter reduction, duplex scanning agreed in 16 vessels and correctly detected a focal narrowing in nine of the remaining ten vessels. Ten of 11 occluded renal arteries were correctly identified by duplex scanning. Duplex scanning determined the location of the renal artery lesion with an accuracy of 95% (kappa 0.74). Since duplex scanning can accurately demonstrate and locate focal renal artery stenosis, we believe it may become an accurate screening test for renovascular hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)