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Biomedical subjects

J C Marek

Publications and source records attributed to J C Marek.

5 recordsLinked to original sources
PubMed1991

Recanalization of chronically occluded aortocoronary saphenous vein bypass grafts by extended infusion of urokinase: initial results and short-term clinical follow-up.

Chronic occlusion of saphenous vein aortocoronary bypass grafts is a common problem. Although percutaneous transluminal angioplasty of a saphenous vein with a stenotic lesion is feasible, angioplasty alone of a totally occluded vein graft yields uniformly poor results. Patients with such occlusion are often subjected to repeat aortocoronary bypass surgery. Experience with a new technique that allows angioplasty to be performed in a totally occluded saphenous vein bypass graft is reported. This technique utilizes infusion of prolonged low dose urokinase directly into the proximal portion of the occluded graft. Forty-six consecutive patients with 47 totally occluded grafts were studied. Patients had undergone end to side saphenous vein bypass grafting 1 to 13 (mean 7) years previously. All patients presented with new or worsening angina pectoris with ST-T changes or non-Q wave acute myocardial infarction and all had a totally occluded saphenous vein bypass graft. The new technique entailed the positioning of an angiographic catheter into the stub of the occluded graft and the advancement of an infusion wire into the graft. Patients were returned to the coronary care unit, where urokinase was delivered at a dose of 100,000 to 250,000 U/h. The total dose of urokinase ranged from 0.7 to 9.8 million U over 7.5 to 77 h (mean 31). After therapy, recanalization was seen in 37 (79%) of the 47 grafts. In 20 successfully treated patients, angiography was performed 1 to 24 (mean 11) months after treatment; 13 (65%) of these grafts were patent.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

The effect of predilatation on coronary angioplasty-induced vessel wall injury.

Fifty-four patients presenting with stenotic lesions in a major coronary artery visually estimated by diagnostic angiography to be greater than 90% but less than 100% were randomized to one of two angioplasty regimens, predilatation (group 1) or no predilatation (group 2). In group 1, the artery was initially dilated with a 2 mm balloon followed by a balloon that was considered by the operator to be the definitive size to fully dilate the target vessel. In group 2, the artery was dilated with a balloon deemed the definitive size to complete the angioplasty procedure. There were no statistical differences between groups with respect to age, sex, history of unstable angina, or prior acute myocardial infarction. There were also no significant differences in the angiographic characteristics of the coronary lesions including artery location, lesion length, concentric or eccentric morphology, tubular versus discrete stenosis, calcium in lesions, or lesions on a bend. Following angioplasty, luminal filling defects were present in 5% of the predilated group and in 9% of the nonpredilated group (p = NS). The incidence of luminal border haziness at the dilatation site did not differ between groups, seven (35%) in group 1 versus eight (24%) in group 2. Angiographic evidence of a linear dissection at the angioplasty site was also similar between groups, one (5%) in group 1 versus five (15%) in group 2. Occlusive complications were witnessed in 10% of the predilated group and 12% of the nonpredilated group (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗