Evaluation of peripheral arterial bypass grafts with multi-detector row CT angiography: comparison with duplex US and digital subtraction angiography.
OBJECTIVE
To assess the technical feasibility of multi-detector row computed tomographic (CT) angiography in the assessment of peripheral arterial bypass grafts and to evaluate its accuracy and reliability in the detection of graft-related complications, including graft stenosis, aneurysmal changes, and arteriovenous fistulas.


METHODS
Four-channel multi-detector row CT angiography was performed in 65 consecutive patients with 85 peripheral arterial bypass grafts. Each bypass graft was divided into three segments (proximal anastomosis, course of the graft body, and distal anastomosis), resulting in 255 segments. Two readers evaluated all CT angiograms with regard to image quality and the presence of bypass graft-related abnormalities, including graft stenosis, aneurysmal changes, and arteriovenous fistulas. The results were compared with McNemar test with Bonferroni correction. CT attenuation values were recorded at five different locations from the inflow artery to the outflow artery of the bypass graft. These findings were compared with the findings at duplex ultrasonography (US) in 65 patients and the findings at conventional digital subtraction angiography (DSA) in 27.


RESULTS
Image quality was rated as good or excellent in 250 (98%) and in 252 (99%) of 255 bypass segments, respectively. There was excellent agreement both between readers and between CT angiography and duplex US in the detection of graft stenosis, aneurysmal changes, and arteriovenous fistulas (kappa = 0.86-0.99). CT angiography and duplex US were compared with conventional DSA, and there was no statistically significant difference (P >.25) in sensitivity or specificity between CT angiography and duplex US for both readers for detection of hemodynamically significant bypass stenosis or occlusion, aneurysmal changes, or arteriovenous fistulas. Mean CT attenuation values ranged from 232 HU in the inflow artery to 281 HU in the outflow artery of the bypass graft.


CONCLUSIONS
Multi-detector row CT angiography may be an accurate and reliable technique after duplex US in the assessment of peripheral arterial bypass grafts and detection of graft-related complications, including stenosis, aneurysmal changes, and arteriovenous fistulas.
Institute of Diagnostic Radiology, University Hospital Zurich, Rämistrasse 100, 8091 Zurich, Switzerland.
Jürgen K
JK
Willmann
Dieter
D
Mayer
Martin
M
Banyai
Lotus M
LM
Desbiolles
Francis R
FR
Verdun
Burkhardt
B
Seifert
Borut
B
Marincek
Dominik
D
Weishaupt
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000714:Anastomosis, Surgical; D000783:Aneurysm / Q000175:diagnosis / Q000209:etiology; D015901:Angiography, Digital Subtraction; D001157:Arterial Occlusive Diseases / Q000601:surgery*; D001164:Arteriovenous Fistula / Q000175:diagnosis / Q000209:etiology; D001705:Bioprosthesis; D019917:Blood Vessel Prosthesis Implantation; D005260:Female; D006083:Graft Occlusion, Vascular / Q000175:diagnosis; D006801:Humans; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011183:Postoperative Complications / Q000175:diagnosis; D011446:Prospective Studies; D012501:Saphenous Vein / Q000637:transplantation*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D018616:Ultrasonography, Doppler, Duplex; D014654:Vascular Patency