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K Ehrhard

Publications and source records attributed to K Ehrhard.

5 recordsLinked to original sources
PubMed2006

Detection of vein graft disease using 4-row computed tomography. Evaluation of coronary bypass graft patency and correlation with the Ca-score.

BACKGROUND: Multi-row computed tomography (MDCT) is a promising non-invasive technique and capable of rapid imaging of cardiac structures, including coronary arteries and bypass grafts during a single held breath. In this study, we evaluated coronary artery bypass graft (CABG) patency by comparing 4-slice computed tomography with conventional contrast angiography. One disadvantage of MDCT is the limited diagnostic accuracy with + increased calcification of the grafts. Therefore, the correlation between Ca-grading and diagnostic accuracy was examined. METHODS: We examined 30 patients with 104 bypass grafts with a 4-row MDCT scanner. On the basis of the Ca-score, patients were divided into 3 groups. RESULTS: It was possible to assess the exact degree of stenosis in 25 of 32 > 50% stenoses with 4-row MDCT, 7 stenoses were underestimated. All occlusions in 21 patients were identified correctly, 33 graft segments were underestimated in MDCT, of which 28 were in the group with a Ca-score of > 800. CONCLUSIONS: MDCT allows non-invasive angiographic evaluation of coronary bypass grafts with a high diagnostic accuracy. However, the method strongly depends on the degree of vascular calcification and underrates the degree of stenosis subject to the Ca-score. This is a distinct limitation in distal vascular segments of small calibre which cannot be validly displayed. In patients with low or moderate Ca-score values, MDCT coronary angiography is promising new technique with a high diagnostic accuracy for the detection of graft stenosis or occlusions.

Aged↗
PubMed2004

[Non-invasive assessment of coronary artery bypass grafts -- an update].

The limited lifetime and the correlation between graft occlusion and recurring symptoms underline the need for repeated imaging of coronary artery bypass grafts. CT and MRI allow for non-invasive imaging of coronary bypasses with high accuracies concerning the patency of these vessels. Multidetector CT seems to be the CT technique of choice, especially after the introduction of 16 slice CT scanners for morphologic assessment of coronary artery bypass grafts. Compared with MRI, CT is a robust technique for assessment of cardiac anastomoses, native coronary arteries, and for the detection of graft stenoses. MRI, however, is able to deliver functional information about the grafts and the recipient coronary arteries by determining the coronary flow reserve. Furthermore, it can be integrated in a multiparametric MR examination protocol. The follow-up of asymptomatic patients can primarily be done by these non-invasive techniques as nearly every third patient reveals an asymptomatic bypass occlusion 5 years after operation. Furthermore, patients with atypical complaints after the operation may undergo non-invasive imaging as long as documented patency of the bypass averts coronary angiography. Patients with recurrent angina pectoris and/or myocardial ischemia discovered by other cardiologic tests have to undergo coronary angiography.

Coronary Artery Bypass↗
PubMed2002

[Occlusion by catheter intervention in patent foramen ovale via additional transseptal puncture].

In patients with a cryptogenic cerebral ischemia, the percutaneous closure of a patent foramen ovale (PFO) has gained increasing acceptance as an alternative strategy to prevent paradoxical embolism. Promising data with low recurrence rates have been reported for several self-expanding double disk devices. The implantation of the device is usually performed by passing the PFO. However, in one patient with a TIA (m, 43 years) transesophageal echocardiography (TEE) revealed an atrial septum abnormality with a hypermobile septum and a very small distance (approximately 12 mm) between the PFO channel and the anterior mitral valve leaflet, which was too short to accommodate the regular implantation procedure of the device via the PFO-channel itself. In this particular case the device (PFO-Star TSD) was advanced to the left atrium via an additional transseptal puncture--performed under TEE guidance--to allow for complete closure of the PFO without impairment of the mitral valve function. No periinterventional complications were observed. During the follow-up period of 9 months the patient was completely asymptomatic with no functional impairment of the mitral valve and no residual intracardiac shunt.

Adult↗
PubMed1997

[CT-angiography in carotid stenosis].

PURPOSE: Prospective evaluation of the accuracy of CT angiography (CTA) with different postprocessing for extracranial carotid artery in comparison with DSA. METHOD: One hundred patients were studied with standardized CTA. For postprocessing, MPR, MIP, and 3D reconstruction based on segmentation with upper and lower threshold were used. Intravascular density profiles were considered. All CTA studies were correlated with intra-arterial angiography. The degree and classification of stenoses was determined using the guidelines established by the NASCET collaborators. RESULTS: Measurement of stenosis was possible by MPR in 82.5%, by MIP in 85%, and 3D in 100%. Correct classification was found in 65.5% for MPR, 66% for MIP and 88.5% for 3D. The sensitivity for severe stenoses was 74% for MPR, 82% for MIP, and 93% for 3D. The specificity of these methods was 98%, 96%, and 97%, respectively. All carotid occlusions were correctly identified, no carotid artery was wrongly classified as occluded. CONCLUSIONS: CT angiography allows reliable examinations in carotid artery stenoses and occlusions. 3D reconstruction based on threshold segmentation is superior to MPR and MIP. In some circumstances, e.g., carotid occlusion, further investigation by invasive procedures is not necessary.

Angiography↗