skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Magnetic Resonance Angiography of Nonferromagnetic Iliac Artery Stents and Stent-Grafts: A Comparative Study in Sheep

Abstract

Purpose: To compare nonferromagnetic iliac artery prostheses in their suitability for patency monitoring with magnetic resonance angiography (MRA) using conventional angiography as a reference. Methods: In experiment 1, three Memotherm stents were inserted into the iliac arteries of each of six sheep: two 'tandem' stents on one side and a single stent on the other side. In experiment 2, four prostheses (normal and low-porosity Corvita stent-grafts, Memotherm, ZA-stent) were inserted in each of 11 sheep. Patency was monitored before and 1, 3, and 6 months after insertion with 3D phase-contrast and two 2D time-of-flight sequences (TOF-1: TR/TE = 18/6.9, TOF-2: 13/2.5) with and without contrast at 1.5 T. On 206 coronal MIP images (72 pre-, 134 post-stenting), three readers analyzed 824 iliac segments (206 x 4) for patency and artifacts. Results: There was no difference in the number of artifacts between tandem and single iliac Memotherm stents. The ZA-stent induced significantly fewer artifacts than the other prostheses (p < 0.00001). With MRA, patency of the ZA-stent was correctly diagnosed in 88% of cases, which was almost comparable to nonstented iliac segments (95%), patency of the Memotherm stent in 59%, and of the Corvita stent-grafts in 57% and 55%. The TOF-2more » sequence with contrast yielded the best images. Conclusion: MRA compatibility of nonferromagnetic prostheses depends strongly on the design of the device. MRA may be used to monitor the patency of iliac ZA-stents, whereas iliac Memotherm stents and Corvita stent-grafts appear to be less suited for follow-up with MRA.« less

Authors:
; ; ; ; ; ;  [1];  [2];  [1]
  1. Department of Diagnostic Radiology, University of Technology, Pauwelsstrasse 30, D-52057 Aachen (Germany)
  2. Department of Radiology, Box 292, Fairview University of Minnesota Hospital and Clinic, 420 Delaware St. SE, Minneapolis, MN 55455 (United States)
Publication Date:
OSTI Identifier:
21080275
Resource Type:
Journal Article
Resource Relation:
Journal Name: Cardiovascular and Interventional Radiology; Journal Volume: 22; Journal Issue: 5; Other Information: DOI: 10.1007/s002709900414; Copyright (c) 1999 Springer-Verlag New York Inc; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; ARTERIES; BIOMEDICAL RADIOGRAPHY; GRAFTS; IMAGES; MAGNETIC RESONANCE; PROSTHESES; SHEEP; TIME-OF-FLIGHT METHOD

Citation Formats

Schuermann, Karl, Vorwerk, Dierk, Buecker, Arno, Neuerburg, Joerg, Grosskortenhaus, Stefanie, Haage, Patrick, Piroth, Werner, Hunter, David W., and Guenther, Rolf W.. Magnetic Resonance Angiography of Nonferromagnetic Iliac Artery Stents and Stent-Grafts: A Comparative Study in Sheep. United States: N. p., 1999. Web. doi:10.1007/S002709900414.
Schuermann, Karl, Vorwerk, Dierk, Buecker, Arno, Neuerburg, Joerg, Grosskortenhaus, Stefanie, Haage, Patrick, Piroth, Werner, Hunter, David W., & Guenther, Rolf W.. Magnetic Resonance Angiography of Nonferromagnetic Iliac Artery Stents and Stent-Grafts: A Comparative Study in Sheep. United States. doi:10.1007/S002709900414.
Schuermann, Karl, Vorwerk, Dierk, Buecker, Arno, Neuerburg, Joerg, Grosskortenhaus, Stefanie, Haage, Patrick, Piroth, Werner, Hunter, David W., and Guenther, Rolf W.. 1999. "Magnetic Resonance Angiography of Nonferromagnetic Iliac Artery Stents and Stent-Grafts: A Comparative Study in Sheep". United States. doi:10.1007/S002709900414.
@article{osti_21080275,
title = {Magnetic Resonance Angiography of Nonferromagnetic Iliac Artery Stents and Stent-Grafts: A Comparative Study in Sheep},
author = {Schuermann, Karl and Vorwerk, Dierk and Buecker, Arno and Neuerburg, Joerg and Grosskortenhaus, Stefanie and Haage, Patrick and Piroth, Werner and Hunter, David W. and Guenther, Rolf W.},
abstractNote = {Purpose: To compare nonferromagnetic iliac artery prostheses in their suitability for patency monitoring with magnetic resonance angiography (MRA) using conventional angiography as a reference. Methods: In experiment 1, three Memotherm stents were inserted into the iliac arteries of each of six sheep: two 'tandem' stents on one side and a single stent on the other side. In experiment 2, four prostheses (normal and low-porosity Corvita stent-grafts, Memotherm, ZA-stent) were inserted in each of 11 sheep. Patency was monitored before and 1, 3, and 6 months after insertion with 3D phase-contrast and two 2D time-of-flight sequences (TOF-1: TR/TE = 18/6.9, TOF-2: 13/2.5) with and without contrast at 1.5 T. On 206 coronal MIP images (72 pre-, 134 post-stenting), three readers analyzed 824 iliac segments (206 x 4) for patency and artifacts. Results: There was no difference in the number of artifacts between tandem and single iliac Memotherm stents. The ZA-stent induced significantly fewer artifacts than the other prostheses (p < 0.00001). With MRA, patency of the ZA-stent was correctly diagnosed in 88% of cases, which was almost comparable to nonstented iliac segments (95%), patency of the Memotherm stent in 59%, and of the Corvita stent-grafts in 57% and 55%. The TOF-2 sequence with contrast yielded the best images. Conclusion: MRA compatibility of nonferromagnetic prostheses depends strongly on the design of the device. MRA may be used to monitor the patency of iliac ZA-stents, whereas iliac Memotherm stents and Corvita stent-grafts appear to be less suited for follow-up with MRA.},
doi = {10.1007/S002709900414},
journal = {Cardiovascular and Interventional Radiology},
number = 5,
volume = 22,
place = {United States},
year = 1999,
month = 9
}
  • Fat-suppressed, three-dimensional magnetic resonance angiography (3D MRA) was performed on nine patients with 11 iliac artery stenoses following atherectomy or stent placement. The MRA accurately depicted continued patency, restenosis, or aneurysm formation when compared with immediate posttreatment conventional arteriography. Therefore MRA is accurate and can be used independently for clinical decision making.
  • The endovascular exclusion of an isolated iliac artery aneurysm is recognized as a safe and favorable alternative to open surgical repair, with low associated morbidity and mortality. It has particular advantages in the treatment of internal iliac artery aneurysm (IIAA) given the technical difficulties associated with open surgical repair deep within the pelvis. We describe the use of customized tapered stent-grafts in the exclusion of wide-necked IIAA in five male patients considered high-risk for conventional surgical repair, in whom the common and external iliac artery morphology precluded the use of standard endovascular devices. In each case, IIAA outflow was selectivelymore » embolized and the aneurysm neck excluded by placement of a customized tapered stent-graft across the internal iliac artery origin. This technique was extremely effective, with 100% technical success, no serious associated morbidity, and zero mortality. In all five patients sac size was stable or reduced on computed tomography follow-up of up to 3 years (mean, 24.4 months), with a primary patency rate of 100%. We therefore advocate the use of customized tapered stent-grafts as a further endovascular option in the management of IIAA unsuitable for conventional endovascular repair.« less
  • The objective of this study was to determine the anatomical relationship and juxtaposition between the common iliac artery and vein in a population of patients with aortic aneurysmal disease and a population clinically and radiologically free of atheroma. It was a retrospective study of 100 consecutive patients undergoing computed tomographic assessment of abdominal aortic aneurysm prior to endovascular or open surgical repair and 100 patients undergoing computed tomographic assessment for other pathologies who did not have clinical or imaging signs of aorto-iliac atheroma. In both groups the anatomical relationship between the right and left iliac artery and vein was studied,more » and the thickness of the fat plane separating the artery from the vein measured. The right iliac vein was posterolateral to the artery at the level of the common iliac artery bifurcation in 95% of patients in both groups. At the same level the left iliac vein was posterior in 23% (p {<=} 0.001). Eighty-three percent of patients in the aneurysm group had a fat plane between the right artery and vein that measured 0 mm (no visible fat plane = 52%) to 1 mm (= 31%). Ninety-eight percent of patients in the aneurysm group had a measurable fat plane between the left iliac artery and vein of up to 5 mm (p = 0.001). Six percent of the control group demonstrated no visible fat plane between the right iliac artery and vein (p {<=} 0.001), while the fat plane measured more than 1 mm (1-5 mm) on the left in 100%. We conclude that in patients where conduit construction is required for aortic stent-graft access, the anatomical configuration and intimate relationship of the iliac arteries and veins should be assessed and taken into account at CT scan evaluation. The distal right common iliac artery should not be used, as venous damage can be predicted from the anatomical and intimate relationship of the iliac artery and vein at this level in patients with atheroma and the difficulties this relationship presents if venous repair is necessary.« less
  • The objective of the study was to prove the value of single-dose contrast-enhanced magnetic resonance angiography [three-dimensional (3D) ceMRA] in abdominal and iliac arteries versus the reference standard intra-arterial digital subtraction angiography (i.a.DSA) when indicating a therapy. Patients suspected of having abdominal or iliac artery stenosis were included in this study. A positive vote of the local Ethics Committee was given. After written informed consent was obtained, 37 patients were enrolled, of which 34 were available for image evaluation. Both 3D ceMRA and i.a. DSA were performed for each patient. The dosage for 3D ceMRA was 0.1 mmol/kg body weightmore » in a 1.5-T scanner with a phased-array coil. The parameters of the 3D-FLASH sequence were as follows: TR/TE 4.6/1.8 ms, effective thickness 3.5 mm, matrix 512 x 200, flip angle 30{sup o}, field of view 420 mm, TA 23 s, coronal scan orientation. Totally, 476 vessel segments were evaluated for stenosis degree by two radiologists in a consensus fashion in a blinded read. For each patient, a therapy was proposed, if clinically indicated. Sensitivity, specificity, positive and negative predictive values, and accuracy for stenoses {>=}50% were 68%, 92%, 44%, 97%, and 90%, respectively. In 13/34 patients, a discrepancy was found concerning therapy decisions based on MRA findings versus therapy decisions based on the reference standard DSA. The results showed that the used MRA imaging technique of abdominal and iliac arteries is not competitive to i.a. DSA, with a high rate of misinterpretation of the MRAs resulting in incorrect therapies.« less
  • Purpose. To evaluate the efficacy of iliac artery stent placement for relief of claudication in patients with both iliac and superficial femoral artery (SFA) lesions. Methods. Stent placement for only iliac artery occlusive disease was performed in 94 limbs (74 patients) with both iliac and SFA occlusive disease on the same limb. All procedures were performed because intermittent claudication did not improve after continuation of antiplatelet medication therapy and home-based exercise for 3 months. Rutherford classification was 2 in 20 limbs and 3 in 74 limbs. Patients with critical limb ischemia were excluded. Median duration of follow-up was 40 months.more » Primary patency rates of the iliac stent, clinical improvement rates, and risk factors for requiring additional SFA procedures were evaluated. Results. Primary patency rates of the iliac stent at 1, 3, 5, and 7 years were 97, 93, 79, and 79 %, respectively. The initial clinical improvement rate was 87 %. Continued clinical improvement rates at 1, 3, 5, and 7 years were 87, 81, 69, and 66 %, respectively. SFA Trans-Atlantic Inter-Society Consensus (TASC) II C/D lesion was a significant risk factor for requiring additional SFA procedures. Conclusion. Intermittent claudication was relieved by iliac stent placement in most patients with both iliac and SFA lesions. Thus, the indications for treatment of the SFA intended for claudicants should be evaluated after treatment of the iliac lesion.« less