Techniques for lower-limb angiography: a comparative study

Routine Use of Three-Dimensional Contrast-Enhanced Moving-Table MR Angiography in Patients with Peripheral Arterial Occlusive Disease: Comparison with Selective Digital Subtraction Angiography

PURPOSE

To compare the diagnostic accuracy of contrast-enhanced (CE) three-dimensional (3D) moving-table magnetic resonance (MR) angiography with that of selective digital subtraction angiography (DSA) for routine clinical investigation in patients with peripheral arterial occlusive disease.

METHODS

Thirty-eight patients underwent CE 3D moving-table MR angiography of the pelvic and peripheral arteries. A commercially available large-field-of-view adapter and a dedicated peripheral vascular phased-array coil were used. MR angiograms were evaluated for grade of arterial stenosis, diagnostic quality, and presence of artifacts. MR imaging results for each patient were compared with those of selective DSA.

RESULTS

Two hundred and twenty-six arterial segments in 38 patients were evaluated by both selective DSA and MR angiography. No complications related to MR angiography were observed. There was agreement in stenosis classification in 204 (90.3%) segments; MR angiography overgraded 16 (7%) segments and undergraded 6 (2.7%) segments. Compared with selective DSA, MR angiography provided high sensitivity and specificity and excellent interobserver agreement for detection of severe stenosis (97% and 95%, kappa = 0.9 +/- 0.03) and moderate stenosis (96.5% and 94.3%, kappa = 0.9 +/- 0.03).

CONCLUSION

Compared with selective DSA, moving-table MR angiography proved to be an accurate, noninvasive method for evaluation of peripheral arterial occlusive disease and may thus serve as an alternative to DSA in clinical routine.

Correlation between angiographic runoff and intraoperative hydraulic impedance with regard to graft patency

The aim of this study was to evaluate the correlation between peripheral runoff estimated by the SVS/ISCVS scoring system and intraoperatively measured outflow. Sixty-six patients received 27 femoropopliteal and 39 femorocrural ePTFE grafts. During the operation, peripheral resistance and hydraulic impedance were measured by means of the extracorporeal-bypass-flow method. Angiographic runoff was estimated according to the revised SVS/ISCVS system. Patients were entered in a graft surveillance program and patency was calculated after 3 years. The relation between the angiographic runoff score and graft patency as well as correlations between hemodynamic data, peripheral resistance, and hydraulic impedance were calculated. Primary and secondary patency rates for femoropopliteal grafts were 44% and 60% and those for femorocrural bypasses were 35% and 45%. Mean angiographic vessel diameters for above-knee and below-knee popliteal arteries were 0.51 +/- 0.02 mm and 0.47 +/- 0.04 mm. Diameters of crural arteries were 0.34 +/- 0.03 mm (posterior tibial artery), 0.27 +/- 0.02 mm (anterior tibial artery) and 0.26 +/- 0.21 mm (peroneal artery). The differences in diameter between popliteal and crural grafts were statistically significant ( p < 0.01). Calculated correlations between the preoperative score and hemodynamic, resistance, and impedance values or patency rates were generally poor and statistically not significant. A statistical significant correlation was found only between SVS/ISCVS score and recipient vessel diameters. The angiographic runoff did not correlate with peripheral resistance, impedance, or patency rates. Patients with angiographically poor outflow should additionally be evaluated with duplex sonography or magnetic resonance angiography and should not be denied peripheral reconstructions.

Optimized diagnostic angiography in high-risk patients with severe peripheral vascular disease

Conventional arteriography remains the usual method for preoperative assessment of severe peripheral vascular disease (PVD). Unfortunately, many peripheral arteriograms are still performed with a suboptimal technique, which can cause significant diagnostic errors in patients with severe PVD. A suboptimal technique may be due to poor collimation (causing incorrect exposure and incorrect gray scale), excessive patient-film distance (magnification unsharpness), inadequate volume or density of contrast material, poor contrast resolution (screen-film arteriography), nonselective injection, patient movement, and pressure from restraints or incorrect patient position (failure to profile lesions, pseudo-occlusion from external pressure or plantar flexion). The technique of selective digital subtraction arteriography (DSA) allows one to avoid these errors. The superior contrast resolution of DSA allows use of lower concentrations of contrast material. Selective injection into the external iliac artery allows proper positioning and improves image quality. Demonstration of distal vessels is best achieved by using biplane arteriography. For patients with severe resting ischemia, especially those with diabetes, high-quality selective DSA is essential to ensure that all distal vessels suitable for distal bypass grafting are identified. When properly performed, selective DSA remains the investigation of choice for reliably demonstrating arterial anatomy in high-risk patients with severe PVD.

Lower extremity angiography: improved image quality and outflow vessel detection with bilaterally antegrade selective digital subtraction angiography. A blinded prospective intraindividual comparison with aortic flush digital subtraction angiography

RATIONALE AND OBJECTIVES

To introduce routine bilaterally antegrade selective stationary digital subtraction angiography (DSA), and prospectively compare it with unselective stationary DSA in the detection of calf arteries and assess additional time and complication rate.

METHODS

Twenty-five patients received one unselective and two separate antegrade selective studies of each calf. Images were evaluated for image quality, number of depicted run-off vessels, and potential crural bypass recipient arteries.

RESULTS

Bilaterally antegrade selective DSA was significantly superior in image quality and motion artifacts (P < 0.01). The number of adequately depicted run-off arteries per calf increased from 79% (2.37 of 3) to 96% (2.89 of 3) for legs with advanced peripheral vascular disease (PVD). Seventy-nine instead of 62 potential bypass recipients were identified (P = 0.002). Mean procedure time needed for selective catheterizations was 7 minutes. No adverse events were seen.

CONCLUSIONS

Bilaterally antegrade selective DSA clearly is superior to aortic run-off DSA depicting tibial arteries. It requires comparatively small additional effort. Outflow vessel detection essentially is independent of advanced PVD.

Variations of the arterial anatomy of the foot

Reconstruction of the arteries of the foot in patients with severe chronic arterial occlusive disease has become a routine and valuable procedure. However, it is frequently difficult to select the optimal site for the distal arterial anastomosis. In order to determine the most important anatomic variations of foot arteries and the relationship of the dorsalis pedis artery to crossing tendons, the following study was performed in 30 cadaver limbs of 17 persons (9 men and 8 women). Their mean age at death was 69.8 years (range: 42 to 93 years). Methods to evaluate anatomy included anatomic dissection, arteriography, and preparation of corrosion cast models. The latter was performed by injection of liquid plastic and catalyst into the tibial arteries followed by chemical débridement of the soft tissue of the foot. Photographs of the corrosion cast models were taken at various stages of soft tissue dissolution. The dorsalis pedis artery was absent in 6.7% of the cases, and the arcuate artery was absent in 33%. The dorsalis pedis artery arose from the peroneal artery in 6.7%. The dorsalis pedis artery crossed under the extensor hallucis longus tendon at the ankle in 54%, above the ankle in 43%, but below the ankle in only 3%. Our study suggests that the optimal site for the dorsalis pedis artery anastomosis on the foot is the segment distal to the ankle.

Angiography of the lower extremity in atherosclerotic vascular disease. Current techniques

With the vast array of technology available, detailed diagnostic information is now routinely obtained in patients with peripheral vascular disorders. In addition, percutaneous intervention and advanced surgical techniques now safely permit the patient to return to an active life, and in advanced vascular disease, the extremity can be salvaged when previously the only option was amputation. We feel strongly that the maximum amount of information about the arterial system should be obtained throughout the patient's management. In addition, these complex procedures require considerable experience and judgment, and our practice of ongoing communication with the vascular surgery staff during both the diagnostic and the therapeutic phases of the patient's treatment has been extremely beneficial.

Comparison of nonsubtracted digital angiography and conventional screen-film angiography for the evaluation of patients with peripheral vascular disease

Recently, x-ray equipment manufacturers have produced systems capable of generating nonsubtracted digital angiograms (NSDA) of the arteries of the lower extremities with a high-resolution 1,024 x 1,024 matrix. One such system was compared with conventional screen-film angiography (CSFA) for the evaluation of peripheral vascular disease. Both NSDA and CSFA were performed prospectively in an identical fashion on 47 patients. The images were evaluated, and diagnostic adequacy (ie, information sufficient to direct subsequent therapy) and a variety of image quality attributes--vessel opacification, correct timing, complete anatomic coverage, and ease of reading--were compared. CSFA and NSDA provided similar diagnostic information. NSDA was judged superior to CSFA with regard to timing (P less than .001). CSFA was judged superior with regard to anatomic coverage (P less than .001) and ease of reading (P less than .01). NSDA is a promising method for evaluating patients with peripheral vascular disease. Further work is needed to provide more complete anatomic coverage and to improve the quality of the hard-copy images.