Yazar "Vijay, Venkataramana" seçeneğine göre listele
Listeleniyor 1 - 5 / 5
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Clinical and biomaterial evaluation of a new condensed dual-function extracorporeal circuit in reoperation for coronary artery bypass surgery(Sage Publications Ltd, 2009) Gunaydin, Serdar; McCusker, Kevin; Vijay, VenkataramanaPurpose: This prospective, randomized study compared the clinical performance of three types of circuits: a newly introduced, fully-coated, interchangeable open-closed circuit with a dual configuration (hard shell with a bypass shunt), reduced length, and reduced prime of less than 800 cc (CondEC); a completely coated circuit (EC); and a similar uncoated, open circuit with standard length and prime (CONT). Methods: 75 patients undergoing reoperation for coronary revascularization were randomly allocated into three groups (N=25): Group 1: CondEC with shortened tubing, components and an open-closed configuration of low priming volume with a centrifugal pump and a shunt which bypassed the reservoir for closed configuration; Group 2: EC with a roller pump and hard-shell reservoir; Group 3: CONT. Blood samples for CBC, inflammatory mediators [Interleukin-2 (IL-2), Complement-3a (C3a)] and flow cytometry (CD11b/CD18) were collected after induction (T1) and heparin administration (T2), 15 min after cardiopulmonary bypass (CPB) (T3), before cessation of CPB (T4), 15 min after reversal (T5), and the first postoperative day (T6). Results: Leukocyte counts demonstrated significant increases at T4, T5 in CONT but remained stable in EC and CondEC (p<0.05). Platelets were preserved better at T4, T5 in both EC and CondEC study groups (p<0.05). IL-2 and C3a levels were significantly lower at T3, T4, T5 in CondEC and T4, T5 in EC (p<0.05). Blood protein adsorption analysis demonstrated increased amount of microalbumin on CONT fibers (p<0.05). Conclusions: The CondEC is a flexible, dual-function, open/closed configuration system that was easy to use, safe and achieved better biocompatibility when compared to coated and uncoated conventional circuits. (Int J Artif Organs 2009; 32: 802-10)Öğe Clinical and biomaterial evaluation of hyaluronan-based heparin-bonded extracorporeal circuits with reduced versus full systemic anticoagulation in reoperation for coronary revascularization(Lippincott Williams & Wilkins, 2009) Günaydın, Serdar; Farsak, Bora; Mccusker, Kevin; Vijay, Venkataramana; Sarı, Tamer; Onur, M. Ali; Zorlutuna, YamanObjective This prospective randomized study compares full and reduced heparinization on novel hyaluronan-based heparin-bonded circuits vs. uncoated controls under challenging clinical setting including biomaterial evaluation. Methods 100 patients undergoing reoperation for coronary artery bypass grafting were allocated into two equal groups (n = 50): Group one was treated with hyaluronan-based heparin bonded preconnected circuits (Vision HFOGBS, Gish, California, USA) and Group two with identical uncoated controls (Vision HFO, Gish, USA). In the study group, half of the patients (n = 25) received low-systemic heparin (125 IU/kg, ACT>250 s) or full dose like control group. Blood samples were collected after induction of anesthesia (T1) and heparin administration before cardiopulmonary bypass (CPB) (T2),15 min after initiation of CPB (T3), before cessation of CPB (T4),15 min after reversal with protamine (T5), and the first postoperative day at 08: 00 h (T6). Results Platelet counts were preserved significantly better at T5, T6 in hyaluronan groups (P<0.05 vs. control). Serum IL-2 levels were significantly lower at T4, T5 in both hyaluronan groups and C3a levels at T4 and T5 only in low-dose group (P<0.05). Troponin-T levels in coronary sinus blood demonstrated well preserved myocardium in hyaluronan groups. No significant differences in thrombin-antithrombin levels were observed between full and low-dose heparin groups at any time point. Amount of desorbed protein was 1.41 +/- 0.01 in full and 1.43 +/- 0.01 in low dose vs. 1.78 +/- 0.01 mg/dl in control (P<0.05). Conclusion Hyaluronan-based heparin-bonded circuits provided better clinical outcome and less inflammatory response compared with uncoated surfaces. Reduced systemic heparinization combined with hyaluronan-based heparin-bonded circuits is feasible and clinically well tolerated. J Cardiovasc Mad 10:135-142 (C) 2009 Italian Federation of Cardiology.Öğe Clinical performance and biocompatibility of novel hyaluronan-based heparin-bonded extracorporeal circuits(2005) Günaydın, Serdar; Mccusker, Kevin; Vijay, VenkataramanaWe tested documented in vitro and ex vivo advantages of novel hyaluronan based heparin bonded extracorporeal circuits in a prospective randomized study. During the period from June until September 2005, 40 patients undergoing reoperation for coronary artery bypass grafting were allocated into two equal groups (n = 20): Group 1 was treated with hyaluronan-based heparin-bonded circuits and group 2 was treated with uncoated control circuits. Complete blood count, fibrinogen, albumin, C3a, interleukin-2 levels, and thromboelastographic data were documented after induction of anesthesia (T1) and heparin administration before cardiopulmonary bypass (CPB) (T2), 15 minutes after initiation of CPB (T3), before cessation of CPB (T4), 15 minutes after reversal with protamine (T5), and the first postoperative day at 8:00 a.m. (T6). Hollow fibers were collected for consecutive biomaterial analysis by optical and scanning electron microscopy (SEM). Desorbed protein deposition on fibers was compared by spectrophotometry. Leukocyte counts were lower in T4-T6 in group 1 (p < .05). Platelet counts demonstrated significant differences at T4 and T5 in coated group (p < .05). Albumin and fibrinogen levels were better preserved in Group 1 at T4, T5 and T4, T6, consecutively (p < .05). C3a and IL-2 levels were lower at T3-T5 and T4-T5 in intervention group (p < .05). Postoperative hemorrhage was 412 ± 50 mL in group 1 and 684 ± 50 ml in group 2 (p < .05). Respiratory support time was shorter in group 1 versus control (p < .05). Platelet adhesion was significantly lower in intervention group. Amount of desorbed protein was 1.44 ± 0.01 mg/dL in group 1 and 1.94 ± 0.01 mg/dL in control (p < .05). SEM and spectrophotometry demonstrated better surface preservation in the hyaluronan coated group. Novel hyaluronan-based heparin-bonded circuits reduce platelet adhesion-aggregation and protein adsorption and provide better perioperative clinical parameters through platelet, albumin, and fibrinogen-sparing effects.Öğe Comparison of polymethoxyethylacrylate-coated circuits with leukocyte filtration and reduced heparinization protocol on heparin-bonded circuits in different risk cohorts(Sage Publications Ltd, 2006) Günaydin, Serdar; McCusker, Kevin; Vijay, Venkataramana; İşbir, Selim; Sari, Tamer; Onur, Mehmet Ali; Zorlutuna, YamanObjectives: The relative benefits of strategic leukofiltration on polymer-coated and low-dose heparin protocol on heparin-coated circuits were studied across EuroSCORE patient risk strata for three different cohorts. Methods: In a prospective, randomized study, 270 patients undergoing coronary artery bypass grafting were allocated into three groups (n = 90): Group 1 - polymethoxyethylacrylate-coated circuits + leukocyte filters; Group 2 - polypeptide-based heparin-bonded circuits with reduced heparinization; and Group 3 - Control: uncoated circuits. Each group was further divided into three subgroups (n = 30), with respect to low- (EuroSCORE 0-2), medium- (3-5), and high- (6+) risk patients. Blood samples were collected at T1: following induction of anesthesia; T2: following heparin administration; T3: 15 min after CPB; T4: before cessation of CPB; T5: 15 min after protamine reversal; and T6: ICU. Results: In high-risk cohorts, leukocyte counts demonstrated significant differences at T4 and T5 in Group 1, and at T4 in Group 2. Platelet counts were preserved significantly better at T4 and T5 in both groups (p < 0.05 versus control). Serum IL-2 and C3a levels were significantly lower at T3, T4 and T5 in Group 1, and T4 and T5 in Group 2 (p < 0.05). Postoperative bleeding, respiratory support time and incidence of atrial fibrillation were lower in the study groups versus control. Cell counts on filter mesh and heparin-coated fibers/ circuits were significantly higher in the high-risk cohorts versus uncoated fibers. Phagocytic capacity increased on filter mesh, especially in high-risk specimens. SEM evaluation demonstrated better preserved coated circuits. Conclusion: Leukofiltration and coating reduced platelet adhesion, protein adsorption, atrial fibrillation and reduced heparinization acted via modulation of systemic inflammatory response in high-risk groups.Öğe Influence of hematocrit and pump prime on cerebral oxygen saturation in on-pump coronary revascularization(Sage Publications Ltd, 2006) McCusker, Kevin; Chalafant, Anthony; Foe, Gordon de; Günaydın, Serdar; Vijay, VenkataramanaBackground: The couplings between cerebral oxygenation (rSO(2)), on-pump hematocrit and circuit prime are explored in this study. Methods: Thirty-eight consecutive patients undergoing coronary revascularization with cardiopulmonary bypass (CPB) were matched on preoperative hematocrit < 40% and > 40% (n = 16). Similarly, six blood prime patients were matched with six crystalloid prime patients. Hematocrit and rSO(2) levels were then compared on CPB. Results: The preoperative hematocrit > 40% group retained higher levels on pump run (p < 0.01) and significantly higher rSO(2) prior to CPB (64.8 +/- 9.6 versus 73.2 +/- 7.3), and on and off CPB (61.1 +/- 8.8 versus 67.4 +/- 6.4). Blood priming increased absolute rSO(2) (2.3 +/- 6.3 versus -10.9 +/- 5.9) and % rSO(2) (4.7 +/- 11.8 versus -14.2 +/- 7.4%) in the low hematocrit group. Conclusion: Blood primes are instrumental in high-risk and low preoperative hematocrit patients in preventing cerebral oxygen desaturation during initiation and maintenance of CPB.
