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Arterial Grafts (arterial + graft)
Selected AbstractsA New Technique for the Old Arterial Graft: Internal Thoracic ArteryJOURNAL OF CARDIAC SURGERY, Issue 2 2008Ufuk Tutun M.D. It stays patent well in the long-term period, and this evidence is directly related to the superior later outcome in terms of longevity. Coronary artery bypass grafting with multiarterial grafts can be performed safely, and better long-term result can be expected with the use of arterial conduits, especially ITA. We describe a simple and practical technique for the left ITA grafting by dividing the ITA graft and using its proximal and distal parts in situ for the distal left anterior descending (LAD) artery and the obtuse marginal artery grafting. [source] Light and Electron Microscopic Analyses of Autologous Pericardial Tissue Used as a Small-Diameter Arterial Graft in DogsARTIFICIAL ORGANS, Issue 1 2002Won Gon Kim Abstract: As a form of small-diameter arterial graft, we implanted fresh autologous pericardium and pericardium treated with 0.6% glutaraldehyde in the bilateral carotid arteries of dogs and then compared the time-related changes of the grafts explanted after the predetermined periods. The pericardial grafts were implanted in 1 animal each for scheduled periods of 3 days, 2 weeks, 1 month, 3 months, and 6 months. The retrieved grafts were processed for light and electron microscopic analyses following gross observation. The glutaraldehyde-treated small-diameter pericardial vascular grafts showed a better endothelialization of the blood-contacting surface and a slower fragmentation of the collagen layers than the fresh grafts although it has yet to be proven whether these differences are so significant as to affect the patency results between the groups. [source] The Right Gastroepiploic Artery in Coronary Artery Bypass GraftingJOURNAL OF CARDIAC SURGERY, Issue 4 2008Hideki Sasaki M.D. Although some reports presenting good results justify its use in clinical settings, there is still much concern about using the RGEA in bypass surgery. The RGEA demonstrates different behaviors from the internal thoracic artery (ITA) in bypass surgery due to its histological characteristics and anatomical difference, which might contribute to the long-term outcome. Now that left ITA (LITA) to left anterior descending artery (LAD) is the gold standard, other grafts are expected to cover the rest of the coronary arteries. It should be elucidated how we can use other grafts and what we can expect from them. RGEA, as an arterial graft, can be used as an in situ graft or a free graft. The RGEA is mainly used to graft to the right coronary artery (RCA) because of its anatomical position, and its patency is not inferior to that of the saphenous vein (SVG). The RGEA can cover the lateral walls when its length is long enough or by making a composite graft with other grafts. However, when used to graft to the LAD, its mid-term patency is not favorable. [source] Light and Electron Microscopic Analyses of Autologous Pericardial Tissue Used as a Small-Diameter Arterial Graft in DogsARTIFICIAL ORGANS, Issue 1 2002Won Gon Kim Abstract: As a form of small-diameter arterial graft, we implanted fresh autologous pericardium and pericardium treated with 0.6% glutaraldehyde in the bilateral carotid arteries of dogs and then compared the time-related changes of the grafts explanted after the predetermined periods. The pericardial grafts were implanted in 1 animal each for scheduled periods of 3 days, 2 weeks, 1 month, 3 months, and 6 months. The retrieved grafts were processed for light and electron microscopic analyses following gross observation. The glutaraldehyde-treated small-diameter pericardial vascular grafts showed a better endothelialization of the blood-contacting surface and a slower fragmentation of the collagen layers than the fresh grafts although it has yet to be proven whether these differences are so significant as to affect the patency results between the groups. [source] Midterm Results of Off-Pump Coronary Artery Bypass Surgery in 136 Patients: An Angiographic Control StudyJOURNAL OF CARDIAC SURGERY, Issue 1 2006Hakki Kazaz M.D. This study summarizes the midterm results of 136 off-pump bypass surgery patients. Methods: Between January 2000 and March 2002, out of 178 surgical myocardial revascularizations, 136 (76.4%) were off-pump bypass surgery. Complete revascularization was done and especially arterial grafts were used. All patients were followed clinically and with treadmill test for 2 years. Average control angiography was performed at the end of 2-year follow-up. Results: Of all the patients, 56.7% were male and the mean age of the patients was 63.6 ± 7.4 years. A total of 481 anastomoses were performed,136 (28.27%) to the left anterior descending artery (LAD), 135 (28.07%) to the circumflex coronary artery (Cx) branches, 102 (21.20%) to the right coronary artery (RCA), 108 (22.46%) to the D,. The mean graft number was 3.46. We used 96.6% of patients' left internal mammarian artery (LITA), 29.2% radial artery (RA), 4.4% right internal thoracic artery (RITA), and 100% saphenous vein. There were ischemic changes within 12 patients. All ischemic changes came back to normal within 4 and 18 hours, postoperatively. Mean extubation time was 5.36 ± 2.23 hours, mean stay in intensive care unit was 17.53 ± 3.15 hours, mean hospital stay was 5.03 ± 1.29 days. The LITA patency was 99.25%, RA patency was 97.84%, RITA patency was 100%, and saphenous vein patency was 91.79% with control angiography. Conclusion: Off-pump coronary artery bypass graft (CABG) is efficient procedure with lower index of mortality, morbidity, ICU stay, hospital stay, good wound healing, early socialization, and results in lower costs. [source] Time-related Histopathologic Changes in Fresh Frozen Carotid Xenografts in a Pig-to-Goat Implantation ModelARTIFICIAL ORGANS, Issue 10 2009Ji M. Chang Abstract We performed an animal experiment with an emphasis on time-related histopathologic changes to evaluate the clinical feasibility of immunologically nontreated xenogenic vascular grafts. Bilateral porcine carotid arteries were harvested, and then, after short-term freezing at ,70°C, interposed into goats' carotid arteries. An antiplatelet agent was administered orally for 3 months postoperatively. The goats were randomly assigned to five periods of observation (1 week, and 1, 3, 6, and 12 months after implantation); two animals were observed at each of these times. Doppler ultrasonography was performed periodically during the observation period. At predetermined times, grafts were explanted and examined using hematoxylin and eosin, and Masson's trichrome stains. Immunohistochemical evaluations were conducted with T-lymphocyte indicator and von Willebrand factor. Two goats died prematurely, one from respiratory problems related to anesthesia and the other from pneumonia. A total of 16 grafts from the remaining eight animals were evaluated. Grafts were all patent except one at 3 months after transplantation. Histologically, xenogenic arterial grafts showed early endothelial cell loss at 1 week. This was followed by a progressive spread of recipient endothelial cells from the anastomotic site, and re-endothelialization was complete at 1 month. The degree of neointimal and medial thickening increased until 3 months, and then decreased. At 12 months, no additional growth of the intimal or medial layers was observed. Adventitial inflammation became severe at 3 months, but was reduced at 6,12 months. The proportions of CD3-positive T-lymphocytes among inflammatory cell infiltrations were very low. Fresh frozen xenogenic arterial grafts showed acceptable patency throughout the 12-month period and showed no evidence of being unduly influenced by rejection reactions. [source] Changes in Vein Dynamics Ranging from Low to High Pressure Levels as a Determinant of the Differences in Vein Adaptation to Arterial Hemodynamic ConditionsARTIFICIAL ORGANS, Issue 7 2007Yanina Zócalo Abstract:, The causes of the regional differences in venous grafts patency rates are partially understood. Differences in vein dynamics during physiological situations could determine differences in veins' capability to face arterial conditions and could contribute to the dissimilar performance of veins as arterial grafts. In vitro pressure and diameter were measured in four different veins during physiological and arterial (graft) pressure conditions. A diameter,pressure transfer function was designed. Compliance, viscous and inertial properties; circumferential stresses and deformation; and buffering function were calculated. Regional differences in veins' dynamics, but not in buffering function were found during physiological and arterial conditions. The back vein (femoral) showed the least changes when submitted to arterial conditions. Arterial conditions represent different changes in vein dynamics depending on the segment considered. The regional differences in vein dynamics, both at physiological and graft conditions, could contribute to explain the dissimilar results of venous grafts. [source] Effects of potassium channel opener KRN4884 on human conduit arteries used as coronary bypass graftsBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 2 2000Zhen Ren Aims The effects of a new potassium channel opener KRN4884 on human arteries have not been studied. This study was designed to investigate the effects of KRN4884 on the human internal mammary artery (IMA) in order to provide information on possible clinical applications of KRN4884 for preventing and relieving vasospasm of arterial grafts in coronary artery bypass grafting. Methods IMA segments (n = 140) taken from patients undergoing coronary surgery were studied in the organ chamber. Concentration-relaxation curves for KRN4884 were established in the IMA precontracted with noradrenaline (NA), 5-hydroxytryptamine (5-HT), angiotensin II (ANG II), and endothelin-1 (ET-1). The effect of glibenclamide (GBC) on the KRN4884-induced relaxation was also examined in NA or 5-HT-precontracted IMA. Concentration-contraction curves for the four vasoconstrictors were constructed without/with pretreatment of KNR4884 (1 or 30 µm) for 15 min. Results KRN4884 induced less relaxation (P < 0.05) in the precontraction induced by ET-1 (72.9 ± 5.5%) than by ANG II (94.2 ± 3.2%) or NA (93.7 ± 4.1%) with lower EC50 (P < 0.05) for ANG II (,8.54 ± 0.54 log m) than that for NA (,6.14 ± 0.15 log M) or ET-1 (,6.69 ± 0.34 log m). The relaxation in the IMA pretreated with GBC was less than that in control (P < 0.05). KRN4884-pretreatment significantly reduced the contraction (P < 0.05) induced by NA (151.3 ± 18.4% vs 82.7 ± 8.7%), 5-HT (82.7 ± 12.2% vs 30.1 ± 7.3%), and ANG II (24.3 ± 6.3% vs 5.4 ± 1.6%), but did not significantly reduce the contraction induced by ET-1 (P > 0.05). Conclusion KRN4884 has marked vasorelaxant effects on the human IMA contracted by a variety of vasoconstrictors and the effect is vasoconstrictor-selective. [source] |