Biomedical subjects

C Bauters

Publications and source records attributed to C Bauters.

148 records · Page 9Linked to original sources

PubMedDate not supplied

The biology of restenosis.

Recent studies have allowed a better understanding of the biology of restenosis. Neointimal thickening--also referred to as neointimal hyperplasia--occurs in response to experimental arterial injury. This process involves different steps which include smooth muscle cell activation, proliferation, and migration, and the production of extracellular matrix. Neointimal thickening has been identified as one of the mechanisms of restenosis after balloon angioplasty in humans. The factors which control neointimal thickening include growth factors, hormonal factors, and mechanical factors. Delinquent reendothelialization has been shown to have a permissive impact on smooth muscle cell proliferation. In addition to neointimal thickening, arterial remodeling also plays a major role in restenosis. Studies performed on animals and in human subjects have established the potential for "constrictive remodeling" to reduce the vessel lumen after angioplasty. Restenosis thus appears as a multifactorial entity that may be addressed in the future by a combined mechanical and pharmacological approach.

Angioplasty, Balloon↗

PubMedDate not supplied

Coronary angioscopic findings in the infarct-related vessel within 1 month of acute myocardial infarction: natural history and the effect of thrombolysis.

BACKGROUND: Limited angioscopic information is available on the natural history of infarct-related plaque after myocardial infarction (MI), in particular the effect of thrombolysis. METHODS AND RESULTS: We studied with angioscopy the morphological characteristics of the infarct-related lesion in 56 patients between 24 hours and 4 weeks after MI. Forty of these patients were initially treated with a thrombolytic agent. Most lesions were complex (complex + ulcerated shape = 54%). The predominant color of the plaque was yellow in 79% of cases; only 6% were uniformly white. Angioscopically visible thrombus was found in 77% of cases. Despite angioscopic evidence of instability, only 7% of the patients had post-MI angina. During the 1-month time window since the occurrence of MI, there was no significant difference in the angioscopic appearance of the plaque except for a slight increase in uniformly white plaques (P=.07). The use of a thrombolytic agent at the onset of MI was associated with a reduction in thrombus size and less protruding thrombi (P=.02) but not with a decreased frequency of plaque containing thrombi. Furthermore, a trend for more frequently ulcerated plaques (45% versus 16%, P=.06) was associated with the use of a thrombolytic agent. CONCLUSIONS: These results suggest that healing of the infarct-related lesion requires more than 1 month and that an "unstable" yellow plaque with adherent thrombus is common during that period. This finding may partly explain the unique behavior of recent infarct-related lesions, which are more prone to occlude than other lesions.

Angioscopy↗

PubMedDate not supplied

Procedural variables associated with eventual long term angiographic success in patients with recurrent restenosis.

To determine the procedural variables associated with eventual long term angiographic success in patients with recurrent restenosis, we compared two successive PTCAs on the same segment, in the same 16 patients, where the first led to recurrent restenosis but the second to successful long term angiographic result. A long interval since previous PTCA and low inflation pressure are associated with long term success after repeated PTCA; other procedural variables are not linked with long term outcome. This study may help us to predict long term success after a repeated angioplasty procedure.

Aged↗

PubMedDate not supplied

[Percutaneous coronary angioscopy: 200 observations in 100 candidates for angioplasty].

Due to the recent technological advances, it is possible to perform percutaneous coronary angioscopy in a straightforward fashion in most patients. To know the safety and usefulness of this technique we present 200 observations in 100 patients candidates for coronary intervention. We used a coronary angioscope (Baxter, Edwards LIS Division), that can be placed using the conventional technique for percutaneous coronary angioplasty. The system incorporates a proximal occluding balloon, and distally a movable optical fiber. Case selection considered non-ostial coronary segments relatively straight. It was possible to obtain adequate images in 86 percent of cases. The technique is safe in experienced hands: there were two cases of ventricular fibrillation, and two cases of local dissection occurred, none of these associated with clinical consequences. No myocardial infarction, surgery or death, related to this procedure occurred. Valuable diagnostic information is derived from angioscopy as the method provides some histopathological correlation. Stable plaques are usually uniformly white or yellow. Unstable plaques are yellow and ulcerated. Thrombus can be easily recognized in acute coronary syndromes. Also in percutaneously treated segments, the final result and the presence of dissection or hemorrhage can be visualized. Coronary percutaneous angioscopy is safe and brings useful clinical information. Its applications in the clinical practice are still to be determined.

Angioplasty, Balloon, Coronary↗