Covered stents in the treatment of peripheral arterial aneurysms: procedural results and midterm follow-up.

PURPOSE: To evaluate initial and midterm results of percutaneous treatment of peripheral aneurysms using covered stents. METHODS: Between June 1994 and December 1997 we used covered stents (EndoPro System or Passager) on 19 patients with peripheral aneurysms (7 iliac, 5 subclavian, 3 femoral, 3 popliteal, 1 carotid). RESULTS: Successful aneurysm exclusion was achieved in 18 of 19 patients (95%). In the short term (<30 days), one patient died of puncture site hemorrhage complicated by myocardial infarction; two femoral stents were surgically removed because of leakage. At subsequent follow-up (mean 20 months) two further unrelated deaths occurred. At 1 year (intention-to-treat) the stent was patent in 13 of 19 patients (68%) and the aneurysm was excluded in 17 of 19 (89%). CONCLUSION: Treatment of peripheral aneurysms with covered stents has a high rate of immediate procedural success. Continued exclusion of the aneurysms is achieved in a large proportion of patients but there is a relatively high rate of stent thrombosis.

Fibromuscular dysplasia of the renal arteries: comparison of helical CT angiography and arteriography.

OBJECTIVE: We evaluated the role of helical CT angiography rendering techniques in the assessment of renal artery fibromuscular dysplasia. MATERIALS AND METHODS: Twenty hypertensive patients (mean age, 56 years) with angiographically proven renal artery fibromuscular dysplasia were studied by CT angiography. The acquisition protocol was collimation, 3 mm; table speed, 3 mm/sec; and incremental algorithm, one. Maximum-intensity-projection and shaded-surface-display reconstructions and transverse sections were reviewed by a consensus panel to determine the sensitivity and specificity of each technique in revealing renal artery fibromuscular dysplasia. RESULTS: Helical CT angiography enabled successful diagnosis of fibromuscular dysplasia in all 20 patients. Helical CT angiography showed 31 of 34 pathologic arteries and 33 of 38 lesions. Aneurysms (>6 mm) on arteriography (n = 12) were revealed in 83% of transverse sections, 75% of maximum-intensity-projection reconstructions, and 58% of shaded-surface-display reconstructions. Lesions that had a string of pearls appearance on arteriography (n = 19) were shown in 53% of transverse sections, 84% of maximum-intensity-projection reconstructions (p < .05 compared with transverse sections), and 74% of shaded-surface-display reconstructions. Stenoses (n = 7 on arteriography) were revealed in 57% of transverse sections, 71% of maximum-intensity-projection reconstructions, and 57% of shaded-surface-display reconstructions. Maximum intensity projection alone revealed 30 (79%) of the 38 angiographic lesions; however, using both maximum intensity projections and transverse sections increased the sensitivity to 87%. CONCLUSION: Helical CT angiography, especially the combination of transverse sections and maximum-intensity-projection reconstructions, can reliably reveal renal artery fibromuscular dysplasia. However, because some lesions may not be shown, arteriography with pressure measurements remains the only technique that can assess the physiologic significance of the dysplasia.

Percutaneous angioplasty of arteriovenous (Brescia-Cimino) fistulae in children.

The development of a stenosis in a Brescia-Cimino fistula is a major clinical problem that threatens vascular access for dialysis. We reviewed the case notes of 46 children undergoing hemodialysis via Brescia-Cimino fistulae. Ten children (mean age 12.5 years) developed 14 stenoses located in the venous (10), anastomotic (3), or arterial (1) part of the fistula. Three (1 arterial and 2 anastomotic stenoses) of the 14 stenoses were treated surgically; the remaining 11 (10 venous and 1 anastomotic stenoses) were treated by angioplasty. Seventeen angioplasty procedures were performed by the percutaneous venous route under local anesthesia. Mean follow-up was 24 months. Restenosis within 6 months occurred in 5 patients, predominantly those who had angioplasty with low balloon inflation pressures; 1 was treated surgically; 4 underwent repeat angioplasty using higher balloon inflation pressures (3 patients) or a bigger balloon (1 patient). None subsequently developed restenosis. Angioplasty can be safely used to treat stenosis of arteriovenous fistulae, with a high initial (60% freedom from restenosis at 6 months) success rate. In summary, balloon angioplasty, repeated if necessary, is a safe and effective treatment for the majority of stenoses occurring in Brescia-Cimino fistulae. Restenosis can be safely treated by further angioplasty, which is associated with a high rate of ultimate clinical success.

[Helical x-ray computed tomography of renal arteries. Apropos of 300 patients]. / Angioscanographie hélicoïdale des artères rénales. A propos de 300 patients.

PURPOSE: To evaluate the role of helical CT angiography (CTA) in the detection of renal artery stenosis in hypertensive patients. MATERIALS AND METHODS: We studied 300 hypertensive patients (50 prospectively and 250 consecutively) with CTA and arteriography (n = 118). Helical acquisition (collimation 3 mm; pitch = 1, 20 seconds acquisition time) was performed 20-45 seconds after contrast injection (300 mgl/ml; 120 ml, 4 ml/sec). Transverse axial views and 3D reconstructions were analyzed (360 degrees interpolation algorithm, 1 mm overlapped). RESULTS: In the prospective series, CTA sensitivity was 100% for main renal artery stenoses and specificity was 98.2%; however 7/32 renal accessory arteries were not visualized. In the 300 patients studied, seventy-four stenoses were detected. There were 5 false-positive and 5 false-negative studies. Secondary hypertension was detected in 26% of patients (including 14 cases of adrenal hyperplasia). CONCLUSION: CTA is a promising technique for the detection of renal artery stenosis in hypertensive patients.

Popliteal vascular disease: evaluation with spiral CT angiography.

PURPOSE: To evaluate the potential role of spiral computed tomographic (CT) angiography in the diagnosis of popliteal artery disease. MATERIALS AND METHODS: In 26 consecutive patients referred for popliteal arteriography, the authors performed additional spiral CT angiography with the following protocol: 3-5-mm collimation, 4-6 mm/sec table speed, and 2-3-mm overlap during 32 seconds, with use of 110 mL of contrast medium. Axial transverse sections and shaded surface display and multiplanar reformation reconstruction images were analyzed. All patients underwent previous Doppler ultrasound examination. RESULTS: In the 52 arteries imaged, arteriography showed 14 isolated hemodynamically significant (>50% diameter reduction) stenoses (due to popliteal artery entrapment in one case), four occluded arteries, and 11 aneurysms. CT angiography also demonstrated these 14 stenoses and four occlusions. However, axial transverse views at CT angiography showed that eight of the stenoses were associated with other abnormalities (aneurysm in six, popliteal artery entrapment syndrome in one, and cystic adventitial disease in one) and that two of the occlusions resulted from popliteal artery entrapment syndrome (n = 1) and thrombosis of an aneurysm (n = 1). CT angiography also demonstrated the 11 aneurysms shown with arteriography. CONCLUSION: Popliteal artery lesions can be diagnosed with spiral CT angiography, which provides detailed information on the wall and diameter of the artery and relation of the artery to adjacent structures.