Bilateral skeletonized internal thoracic artery graftings in off-pump coronary artery bypass: early result of Y versus in situ grafts.

BACKGROUND: Use of bilateral skeletonized internal thoracic arteries (ITAs) in off-pump coronary artery bypass (OPCAB) retains several advantages that may eventually result in better patient outcomes. We compared the early results of OPCAB using bilateral ITAs as Y grafts with results of OPCAB using bilateral ITAs as in situ grafts. METHODS: A total of 223 consecutive patients who underwent OPCAB using bilateral skeletonized ITAs as Y grafts (group I, n = 113) or in situ grafts (group II, n = 110) were studied. RESULTS: Both the number of distal anastomoses per patient and the number of distal anastomoses per bilateral ITA were higher in group I (3.5 +/- 1.0 and 2.9 +/- 0.7) than in group II (3.0 +/- 0.7 and 2.4 +/- 0.5) (p < 0.01). Hospital mortality was 1.8% (2/113) in group I and 0.9% (1/110) in group II (p = ns). There were no differences in postoperative complications including atrial fibrillation (13.3% vs 10.9%), perioperative myocardial infarction (0.9% vs 2.7%), mediastinitis (0.9% vs 1.8%), and hypoperfusion syndrome (0.9% vs 0%) between groups I and II (p = ns). Postoperative coronary angiographies performed in 110 patients in group I and 108 patients in group II showed 99.0% (382/386) overall patency and 99.4% (319/321) patency for distal anastomoses using ITAs in group I, and 98.1% (312/318) overall patency and 98.1% (258/263) patency for distal anastomoses using ITA in group II. There were no significant differences in graft patency rates between the two groups (p = ns). CONCLUSIONS: Our results demonstrate that OPCAB using bilateral skeletonized ITAs is technically feasible, with excellent graft patency. Using bilateral skeletonized ITAs as Y grafts increases the number of distal anastomoses that can be performed and does not cause additional postoperative morbidity.

Off-pump coronary artery bypass with complete avoidance of aortic manipulation.

BACKGROUND: Off-pump coronary artery bypass (OPCAB) with complete avoidance of aortic manipulation may further reduce perioperative morbidity in addition to the benefits achieved by avoiding cardiopulmonary bypass and cardioplegic arrest. METHODS: We prospectively analyzed 222 consecutive patients with multivessel disease who underwent OPCAB without aortic manipulation (group I), and compared them with 123 consecutive patients who underwent OPCAB using additional free arterial or saphenous vein grafts that were anastomosed on the ascending aorta (group II) and 76 consecutive patients who underwent on-pump conventional coronary artery bypass grafting (group III). RESULTS: No significant differences were noted in operative mortalities among the three groups (2/222, 3/123, and 2/76 in groups I, II, and III, respectively; p = NS). Fewer distal anastomoses were done in group I compared with groups II and III (3.2 +/- 0.9, 3.5 +/- 0.8, and 3.7 +/- 0.9 in groups I, II, and III, respectively; p < 0.001). No differences were noted in the incidences of postoperative morbidities such as mediastinitis, pulmonary complication, and reoperation for bleeding. The incidences of stroke, atrial fibrillation, and acute renal failure were significantly lower in group I than in group III (p < 0.05), although there were no significant differences between groups II and III. The incidence of perioperative myocardial infarction was significantly lower in group I than in groups II and III (p < 0.05), although there was no significant difference between groups II and III. CONCLUSIONS: Our results demonstrate that OPCAB with complete avoidance of aortic manipulation may further reduce the incidence of perioperative morbidities such as stroke, atrial fibrillation, acute renal failure, and perioperative myocardial infarction.

Effects of propofol on the activity of rat glutamate transporter type 3 expressed in Xenopus oocytes: the role of protein kinase C.

We investigated the effects of propofol on one type of glutamate transporter, excitatory amino acid transporter 3 (EAAT3) and the role of protein kinase C (PKC) in mediating these effects. Rat EAAT3 was expressed in Xenopus oocytes. L-glutamate (30 microM)-induced membrane currents were measured. Propofol increased glutamate-induced inward currents significantly at two tested concentrations (30 and 100 microM) but not at other concentrations. Propofol (30 microM) significantly increased V(max), but not K(m) of EAAT3 for glutamate. The combination of phorbol-12-myrisate-13-acetate (PMA, a PKC activator) and propofol did not increase the responses further compared with PMA or propofol alone. Three PKC inhibitors (staurosporine, calphostin C, and chelerythrine) did not affect basal EAAT3 activity but significantly inhibited the propofol-enhanced EAAT3 activity. Our results suggest that propofol enhances EAAT3 activity at clinically relevant concentrations and PKC may mediate these effects.

Prophylactic milrinone during OPCAB of posterior vessels: implication in angina patients taking beta-blockers.

OBJECTIVE: To determine whether a phosphodiesterase type 3 inhibitor can improve hemodynamics during off-pump coronary artery bypass grafting (OPCAB) of posterior vessels in patients on beta(1)-adrenoreceptor blockers. METHODS: Thirty patients scheduled for OPCAB of the obtuse marginal artery (OM), and taking atenolol 100 mg a day were randomized in a double-blind manner to receive either milrinone or placebo. Hemodynamic data were obtained after induction, before pericardial incision, during left anterior descending artery grafting, during OM grafting, and after removal of the stabilizer. During the OM grafting, dopamine was infused when the cardiac index (CI) decreased below 2.0 L/min/m(2), and phenylephrine was infused to maintain the arterial pressure with a CI above 2.0 L/min/m(2). RESULTS: During OM anastomosis, there were significant differences in CI (milrinone [M] = +7.7%, control [C] = -13.7%, p=0.01), SVI (M=-21.5%, C=-35.8%, p=0.03), SvO(2) (M=-2.6%, C=-8.9%, p=0.02), and SVR (M=-28.1%, C=+1.1%, p=0.01) between the two groups, in terms of percentage change from baseline value. Dopamine was required more frequently and at a higher dose in the control group (M=13%, 5.0 microg/kg/min; C=67%, 10.1 microg/kg/min, p<0.05). Phenylephrine was infused in 33% of the patients in the milrinone group compared to 13% in the control group (p>0.05). CONCLUSIONS: Prophylactic milrinone improves CI, SVI and SvO(2) reducing the need for high doses of dopamine during OM anastomosis in patients taking atenolol. Therefore, it can be used as an alternative to dopamine improving hemodynamics and organ perfusion during OPCAB of posterior vessels in patients on beta(1)-blockers.

The effects of lidocaine on the activity of glutamate transporter EAAT3: the role of protein kinase C and phosphatidylinositol 3-kinase.

UNLABELLED: Using two electrode voltage clamps, we investigated the effects of lidocaine on one type of glutamate transporter, EAAT3, and the role of protein kinase C (PKC) and phosphatidylinositol 3-kinase (PI3K) in mediating the lidocaine effects. EAAT3 was expressed in Xenopus oocytes, and membrane currents were recorded after the application of L-glutamate (30 microM). Lidocaine increased glutamate-induced inward currents significantly at 2 concentrations (100 microM and 1 mM), but not at other concentrations. Lidocaine (100 microM) significantly increased the V(max), but not the K(m), of EAAT3 for glutamate compared with control. The action sites of lidocaine on EAAT3 seem to be intracellular, because only intracellularly injected QX314 (permanently charged lidocaine analog) increased the response. The combination of phorbol-12-myrisate-13-acetate, an activator of PKC, and lidocaine did not further increase the responses compared with phorbol-12-myrisate-13-acetate or lidocaine alone, although each of these three groups showed significantly bigger responses than controls. Three PKC inhibitors (staurosporine, calphostin C, and chelerythrine) did not affect the basal EAAT3 activity but abolished lidocaine-enhanced EAAT3 activity. Wortmannin (a specific PI3K inhibitor) inhibited EAAT3 basal activity and lidocaine-enhanced EAAT3 activity. Our results suggest that lidocaine enhances EAAT3 activity at certain concentrations and that PKC and PI3K may mediate these lidocaine effects. IMPLICATIONS: By using the Xenopus oocyte expression system, we investigated the effects of lidocaine on a glutamate transporter (EAAT3). Our findings suggest that lidocaine enhances EAAT3 activity at certain concentrations and that protein kinase C and phosphatidylinositol 3-kinase may mediate these lidocaine effects.

Case report: pulmonary soiling after one-lung ventilation with a bronchial blocker.

PURPOSE: To report a case of pulmonary soiling of the dependent and of the non-dependent remaining lung when a Univent tube was used to achieve one-lung ventilation (OLV). CLINICAL FEATURES: A 61-yr-old, 158-cm, 61-kg woman was scheduled for the resection of a lung cancer in the left lower lobe. An internal diameter 7.0-mm Univent tube was inserted under direct laryngoscopy and positioned via fibreoptic bronchoscopy. Prior to termination of OLV, there was no discharge through the blocker's lumen, aspirated just before deflating the cuff. As soon as the cuff was deflated, however, abundant blood-tinged secretions were aspirated. At the end of the operation, the chest radiograph showed haziness in the right upper lobe and in the remaining left upper lobe. The ineffective removal of secretions through the lumen of the blocker may be one of its main disadvantages. The bronchial blocker is always placed in the non-dependent bronchus for OLV, which may increase the probability of contaminating the dependent lung. Before deflating the blocker, we recommend the steep Trendelenburg position and the presence of a fibreoptic bronchoscope with a suction port at the tracheal carina to prevent overflow of secretions and soiling of the dependent lung. CONCLUSION: Whenever a bronchial blocker is used for OLV, we should be cautious about the possibility that secretions accumulated distal to the blocker may contaminate the dependent or the non-dependent remaining lung.

Hemodynamic changes during posterior vessel off-pump coronary artery bypass: comparison between deep pericardial sutures and vacuum-assisted apical suction device.

BACKGROUND: Displacement of the heart to expose posterior vessels during off-pump coronary artery bypass may cause hemodynamic derangement. The aims of this study were (1) to elucidate the hemodynamic changes during off-pump coronary artery bypass for the obtuse marginal branch (OM) of the left circumflex artery; and (2) to compare the hemodynamic changes caused by a deep pericardial suture technique with those caused by a vacuum-assisted apical suction device for displacement of the heart. METHODS: Hemodynamic changes during posterior vessel off-pump coronary artery bypass were studied in a prospective randomized manner. A deep pericardial suture technique (group 1, n = 10) or a vacuum-assisted apical suction device (group 2, n = 10) was used to facilitate the exposure of the OM. Hemodynamic variables such as cardiac index, stroke volume index (SVI), mean arterial pressure, mean pulmonary artery pressure, central venous pressure, pulmonary capillary wedge pressure, heart rate, systemic vascular resistance, pulmonary vascular resistance, left ventricular stroke work index, and right ventricular stroke work index were monitored during off-pump coronary artery bypass. Hemodynamic data were obtained before revascularization of the left anterior descending coronary artery at a baseline (T0), 3 minutes after heart displacement for revascularization of OM (T1), 3 minutes after the beginning of OM grafting (T2), and 3 minutes after the completion of OM grafting and heart repositioning (T3). RESULTS: There were no significant differences in the baseline hemodynamic variables (T0) between the two groups. In group 1, SVI, cardiac index, left ventricular stroke work index, and right ventricular stroke work index decreased significantly, and central venous pressure and pulmonary capillary wedge pressure increased significantly, during displacement of the heart (T1, p < 0.05). In group 2, SVI decreased significantly, and central venous pressure, pulmonary capillary wedge pressure, and mean pulmonary artery pressure increased significantly during displacement of the heart (T1, p < 0.05). The percent changes of cardiac index, SVI, and right ventricular stroke work index during OM grafting (T2) in comparison with baseline values (T0) were significantly larger in group 1 than in group 2 (cardiac index, 73% +/- 12% versus 90% +/- 11%; SVI, 69% +/- 12% versus 86% +/- 8%; right ventricular stroke work index, 30% +/- 17% versus 71% +/- 25%, in groups 1 versus 2, respectively; p < 0.05). CONCLUSIONS: Displacement of the heart using either a deep pericardial suture technique or a vacuum-assisted apical suction device caused a significant decrease in SVI. The hemodynamic changes during OM grafting were smaller when using a vacuum-assisted apical suction device.