RESUMO
INTRODUCTION: The main limitation of coronary artery bypass grafting (CABG) is rapid neointimal hyperplasia leading to graft failure. AIM: To assess plaque formation in saphenous vein grafts (SVG) covered by an external Dacron stent in comparison with the classical technique. MATERIAL AND METHODS: In the study group vein grafts covered by external stent mesh made of Dacron were implanted. An intravascular ultrasonography (IVUS) study was performed in 35 aorto-coronary SVG covered by an external Dacron stent and in 64 normal SVG during the first year after CABG. In each SVG 25 mm of good quality IVUS image, volumes of lumen, plaque (neointima), outer border of the vein graft (external SVG) and adventitia were calculated in three time periods: 0-130 days, 130-260 days and 260-390 days. RESULTS: Between the first and second time period, lumen volume (mm3) was reduced from 10.33 ±4.4, to 6.80 ±2.23 in the second period and 5.69 ±1.26 in the third one. This effect was much less marked in normal grafts. The corresponding lumen volume (mm3) was: 10.90 ±3.9, 9.15 ±2.94 and 8.92 ±2.93 in consecutive time periods. Plaque volume (mm3) did not change in control grafts during the course of the study, but it increased very significantly in stented grafts from 0.86 ±1.24 in the first period to 2.70 ±1.58 in the second and 3.29 ±2.66 in the third one. CONCLUSIONS: The experimental technique of implanting SVG covered with an external elastic Dacron stent seems to be inferior to traditional ones. This is probably due to the more complicated process of vein implantation and higher micro-injury occurrence during the surgery.
RESUMO
The main cause of the Bland-White-Garland (BWG) syndrome is usually an anomalous origin of the left coronary artery, however, the right coronary artery can be affected as well. We report on the surgical treatment of an adult type BWG syndrome in a 59-year-old male patient. The reason for angiography was anginal pain which occurred 7 years prior to the operation. At that time patient did not agree to undergo surgery, however, symptom aggravation brought him to the hospital again. Because of the vessel anatomy the operator decided to implant a vein graft.
Assuntos
Angioplastia/métodos , Anomalias dos Vasos Coronários/cirurgia , Vasos Coronários/cirurgia , Fibrilação Atrial/etiologia , Fibrilação Atrial/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , SíndromeRESUMO
BACKGROUND: This article provides a biomechanical analysis of the distribution of force in wire sutures used for sternal closure in cardiothoracic surgery. MATERIAL/METHODS: The parameters we measured included displacement in the elastic region, plastic limit, and rupture load on the closure. Force distribution analysis was carried out for every kind of wire suture. A linear regression line of displacement as a function of increasing load was determined for each closure method. RESULTS: Straight wire had less displacement at each load, figure-8 had medium, and interlocking multitwisted (IM) had the most displacement within the elastic range of the specimen. The differences between straight and interlocking multitwisted sutures were statistically significant. When the plastic limit was compared between straight and interlocking multitwisted closure, the differences were statistically significant. In the straight suture the forces used to approximate the sternal halves are perpendicular to the incision. With the figure-8 and interlocking multitwisted suture, the forces are dispersed and the effective approximation force is lower than that applied to the wires. CONCLUSIONS: Straight wires provide good fixation stability for the durability of the sternum, and the somewhat lower strength could be compensated by increasing the number of sutures. The figure-8 and IM have better strength and are less likely to cut the sternum because of advantageous redistribution of shearing forces of the wire as compared to straight closures.
