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Objective: Radial artery harvesting using the less invasive endoscopic technique involves dissection in a narrow tunnel and may cause an injury or induce vasospasm to the conduit. To assess this hypothesis, radial artery segments harvested endoscopically or conventionally were studied for reactivity and integrity. Methods: Rings of radial arteries from 80 CABG patients who had their radial artery harvested either open (n = 40) or endoscopic (n = 40), were attached to a force transducer then subjected to norepinephrine (NE, 10 � 6 M), acetylcholine (ACh, 10 � 5 M), followed by sodium nitroprusside (SNP, 10 � 7 to 10 � 5 M) to test endothelial dependant and non-dependant relaxation. Vessels’ integrity was assessed by microscopic staining with hematoxylin—eosin for muscle layers, Masson trichrome for collagen content and von Gieson for elastica layers. Results: Contraction and relaxation in response to NE, ACh and SNP were similar in both techniques. Arterial layers, collagen content and elastic lamina were preserved in all radial rings. Both techniques were found to be equally efficient in physiological and microscopic tests. Conclusions: The similar reactivity and integrity of the radial artery in both techniques should encourage the less invasive endoscopic approach. # 2008 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Oral analgesia after "fast-track" cardiac anesthesia has not been explored. The aim of this study was to compare two oral oxycodone analgesic regimens.One hundred-twenty patients scheduled for coronary artery bypass grafting were randomly assigned postoperatively to receive immediate-release oxycodone 5 mg and acetaminophen 325 mg (Percocet-5) (group I) per os four times daily, or controlled-release oxycodone 10 mg (OxyContin) (group II) per os every 12 hr and placebo twice daily. Acetaminophen 500 mg per os was used as first-line rescue medication, and immediate-release oxycodone (syrup form) 5 mg per os as second-line rescue medication. Pain intensity was assessed with a visual analogue scale on the first postoperative day, the morning after extubation, and thereafter four times daily for four days. Use of rescue medication and adverse events were recorded.Baseline demographic and operation-related characteristics were similar in both groups. While pain control was good in both groups, the immediate-release group experienced less pain on all postoperative days (P = 0.003), required significantly less rescue medication, and had fewer adverse effects such as somnolence and nausea.Peroral oxycodone is effective for early pain control after fast-track cardiac anesthesia. Immediate-release oxycodone/ acetaminophen appears to provide better analgesia and fewer side effects compared to controlled-release oxycodone.

There are known clinical and laboratory predictors for stroke and death following CABG. The aim of this study was to determine if transthoracic echocardiographic findings prior to CABG have additional predictive value for occurrence of perioperative cerebrovascular accident (CVA) and death. The files of patients who underwent CABG between January 2002 and November 2004, with perioperative echocardiographic assessment were reviewed. Echocardiographic variables examined included LV size, function and hypertrophy, mitral annulus calcification (MAC) and aortic valve calcification (AVC). Patients in whom post-CABG stroke or death was documented were compared with those without these endpoints. Of the 572 patients who met the study criteria, 33 (5.8%) had a neurological event and 26 (4.5%) died, four after a major stroke. One hundred and sixty-seven patients had MAC and 228 AVC. On multivariate analysis, risk factors for stroke were previous stroke (OR=2.91 CI 1.179-7.24; P

Background Intradepartmental and interdepartmental benchmarking requires scoring systems with reliability (calibration) and stability over the complete spectrum of periprocedural risk. The aim of this single-center study was to assess the performance of the 2000 Bernstein-Parsonnet risk stratification model in cardiac surgery, by itself and against the EuroSCORE. Methods A prospective observational design was used. The study group consisted of 1,639 consecutive patients of mean age 64.6 ± 12.04 years who underwent elective or emergency cardiac surgery from January 2003 to June 2004. The probabilities of hospital death were estimated with the 2000 Bernstein-Parsonnet and EuroSCORE algorithms. The correlation of predicted and observed mortality was compared between the two models, and score validity was assessed by calculating the area under the receiver operating characteristic (ROC) curve. Results The patients were stratified into five risk groups according to their scores in the two models. For the 2000 Bernstein-Parsonnet model, findings were as follows: score 0–10: predicted mortality 0%–2.2%, observed mortality 0.6%; score 10.5–20: predicted 2.3%–4.7%, observed 2.3%; score 20.5–30: predicted 4.8%–10%, observed 6.7%; score 30.5–40: predicted 10.1%–23%, observed 11.5%; and score greater than 40: predicted 23.1%–80%, observed 29.9%. For the EuroSCORE, findings were as follows: score 0%–2%: predicted mortality 1.1%, observed mortality 0.6%; score 3%–5%: predicted 2.1%, observed 3.0%; score 6%–8%: predicted 4.1%, observed 3.5%; score 9–11: predicted 7.6%, observed 6.6.%; and score greater than 12: predicted 13.8%, observed 14.0%. There was good agreement between the observed and expected number of deaths, with both models. The area under the ROC curve was higher for the Bernstein-Parsonnet model (0.83, odds ratio [OR] 2.01, 95% confidence interval [CI] 1.75–2.31, p p Conclusions The 2000 Bernstein-Parsonnet model is a simple, objective system for the estimation of hospital mortality in patients undergoing cardiac surgery, with slightly higher calibration and discrimination than the EuroSCORE additive model.

Background: The number of patients awaiting heart transplantation is increasing in proportion to the waiting period for a donor. Studies have shown that coenzyme Q10 (CoQ10) has a beneficial effect on patients with heart failure. Hypothesis: The purpose of the present double-blind, placebo-controlled, randomized study was to assess the effect of CoQ10 on patients with end-stage heart failure and to determine if CoQ10 can improve the pharmacological bridge to heart transplantation. Methods: A prospective double-blind design was used. Thirty-two patients with end-stage heart failure awaiting heart transplantation were randomly allocated to receive either 60 mg U/day of Ultrasome™---CoQ10 (special preparation to increase intestinal absorption) or placebo for 3 months. All patients continued their regular medication regimen. Assessments included anamnesis with an extended questionnaire based partially on the Minnesota Living with Heart Failure Questionnaire, 6-min walk test, blood tests for atrial natriuretic factor (ANF) and tumor necrosis factor (TNF), and echocardiography. Results: Twenty-seven patients completed the study. The study group showed significant improvement in the 6-min walk test and a decrease in dyspnea, New York Heart Association (NYHA) classification, nocturia, and fatigue. No significant changes were noted after 3 months of treatment in echocardiography parameters (dimensions and contractility of cardiac chambers) or ANF and TNF blood levels. Conclusion: The administration of CoQ10 to heart transplant candidates led to a significant improvement in functional status, clinical symptoms, and quality of life. However, there were no objective changes in echo measurements or ANF and TNF blood levels. Coenzyme Q10 may serve as an optional addition to the pharmacologic armamentarium of patients with end-stage heart failure. The apparent discrepancy between significant clinical improvement and unchanged cardiac status requires further investigation.

Previous investigations have shown the effectiveness of sustained intra- or extravascular administration of vascular endothelial growth factor (VEGF) in chronic myocardial ischemia in improvement of left ventricular function. The present investigations were undertaken in order to evaluate efficacy of a single bolus or local intracoronary delivery.Yorkshire pigs underwent placement of a left circumflex artery ameroid occluder. Three weeks later the animals were randomized to treatment with VEGF (20 micrograms) accomplished by local intracoronary delivery system (InfusaSleeve, n = 10), intracoronary bolus infusion (n = 7) or by epicardial implantation of an osmotic delivery system (n = 7). An additional group of animals received intracoronary administration of saline and served as a control (n = 9). Three weeks after initiation of therapy, the animals were evaluated with regard to myocardial perfusion and global as well as regional ventricular function.All three VEGF treatment groups but not the control animals demonstrated a significant increase in the left-to-left (but not right-to-left) collateral index, myocardial blood flow (pre-therapy LCX vs. LAD (average of all groups): 0.76 +/- 0.35 vs. 0.96 +/- 0.38 ml*min-1*g-1, p = 0.03; post-therapy: LCX vs. LAD: 1.16 +/- 0.39 vs. 1.15 +/- 0.28 ml*min-1*g-1, p = NS) and coronary vasodilatory reserve 3 weeks after growth factor administration. The observed increase in VEGF-induced perfusion correlated with improvement in regional ventricular function in all VEGF-treated groups (pre-therapy vs. post-therapy: i.c. VEGF 20 +/- 5.1 vs. 33 +/- 4.8; local VEGF 16 +/- 2.8 vs. 33.6; pump VEGF 17 +/- 3.8 vs. 34 +/- 4.9 p0.05 for all) but not control animals (21 +/- 3.3 vs. 27 +/- 5.8, p = NS).Single intracoronary delivery (intravascular bolus or local delivery) of VEGF is effective in stimulating physiologically significant angiogenesis in porcine model of chronic myocardial ischemia.

Background Cardioplegia is known to affect coronary vascular reactivity. We examined the effects of intermittent cold and continuous warm blood cardioplegia on β-adrenoceptor–mediated, adenosine triphosphate–sensitive K + (K + ATP )–channel–mediated, and endothelium-dependent relaxation and on the myogenic tone of coronary arterioles. Methods Pigs were placed on cardiopulmonary bypass. Hearts were arrested for 1 hour with a cold blood cardioplegic solution administered intermittently (n=12; iCB-CP) or with a warm blood cardioplegic solution delivered continuously (n=12; cWB-CP). Selected hearts (n=6 in each group) were then reperfused for 1 hour. In vitro relaxation responses of precontracted microvessels (50 to 160μm) were studied in a pressurized no-flow state. Results Relaxation in response to isoproterenol (β-adrenergic agonist) was similar after iCB-CP and cWB-CP, whereas forskolin (adenylate cyclase activator)–induced relaxation was impaired more after iCB-CP than after cWB-CP. After reperfusion the respective responses were similar. Both iCB-CP and cWB-CP preserved receptor-mediated, endothelium-dependent relaxation in response to adenosine, 5 * -diphosphate; non–receptor-mediated endothelium-dependent relaxation in response to A23187; endothelium-independent cyclic guanosine monophosphate–mediated relaxation in response to sodium nitroprusside, and K + ATP -channel–mediated relaxation. Relaxations in response to 8-bromo-cyclic guanosine monophosphate (a cyclic guanosine monophosphate–dependent protein kinase activator) and to 8-bromo-cyclic adenosine monophosphate (a cyclic adenosine monophosphate–dependent protein kinase activator) were impaired after iCB-CP alone and after reperfusion, whereas the respective responses were not affected after cWB-CP. Myogenic tone was decreased similarly after iCB-CP and cWB-CP but was not further altered after reperfusion. Cardiac function was similar after iCB-CP and cWB-CP. Conclusions These results suggest that cWB-CP is similar to iCB-CP in its ability to preserve endothelium-dependent relaxation and K + ATP -channel function. The superior preservation of β-adrenergic-cyclic adenosine monophosphate–mediated coronary responses after cWB-CP is brief and associated with minimal improvement of myocardial function and myogenic tone.

Background. Cardiopulmonary bypass (CPB) is associated with alterations in the regulation of organ perfusion and vascular permeability. The purpose of this study was to examine the effects of hypothermic CPB on the regulation of the skeletal muscle microcirculation and the modulating influence of the priming solution. Methods. Sheep were placed on hypothermic CPB with a prime of either Pentastarch hydroxylethyl starch (HS) solution (n = 7), a solution in which HS is conjugated with deferoxamine (n = 7), or Ringer's lactate solution (n = 7). Sheep were placed on hypothermic CPB (27°C) for 90 minutes while the heart was protected with cold blood cardioplegia. Sheep were then separated from CPB and perfused for an additional 3 hours off CPB. Hemodynamics and total water content were measured. Results. In vitro relaxation responses of gracilis muscle arterioles (70 to 180 μm) to the endothelium-dependent agent acetylcholine, the endothelium-independent cyclic GMP-mediated vasodilator sodium nitroprusside, the β-adrenergic agonist isoproterenol, and the adenylate cyclase activator forskolin were studied. No statistically significant hemodynamic differences were observed between groups. However, weight gain was significantly less when the priming solution was HS or HS-deferoxamine compared to when Ringer's lactate was used. Skeletal muscle arteriolar relaxations to the endothelium-dependent vasodilator acetylcholine and the βadrenergic agonist isoproterenol were impaired after CPB in the HS and Ringer's lactate groups. Acetylcholine response was preserved in the HS-deferoxamine group, whereas the response to isoproterenol remained impaired. The responses to sodium nitroprusside and forskolin were similar in all groups. Conclusions. Skeletal muscle microvascular endothelium-dependent relaxation and β-adrenergic relaxation are reduced after CPB using either a crystalloid or HS prime. Skeletal muscle microvascular endothelial dysfunction may be attributable to oxygen-derived free radical-mediated injury, whereas altered β-adrenergic regulation is attributable to mechanisms other than the generation of oxygen-derived free radicals during CPB.

Patients who undergo cardiopulmonary bypass frequently have neuropsychologic dysfunction. This study was undertaken to determine whether altered cerebral perfusion and vascular responses may in part lead to these neuropsychologic changes. Pigs were placed on normothermic cardiopulmonary bypass for 2 hours. Basal cerebral blood flow and in vivo responses to administration by internal carotid artery of neuronally released vasoactive substances were evaluated before and 5 to 15 minutes after termination of cardiopulmonary bypass. Another group of pigs were placed on cardiopulmonary bypass for 2 hours and then perfused off bypass for 1 additional hour. In vitro responses of cerebral arterial microvessels (100 to 175 μm) from both groups were examined in a pressurized (40 mm Hg) no-flow state with videomicroscopy. Vessels from uninstrumented pigs served as control preparations for in vitro studies. Cerebrovascular resistance and cerebral perfusion were maintained constant during cardiopulmonary bypass and after separation from bypass. The internal carotid artery infusion of acetylcholine (cholinergic agonist) caused increased internal carotid artery blood flow before cardiopulmonary bypass but decreased blood flow after cardiopulmonary bypass. After 2 hours of cardiopulmonary bypass, the increase in internal carotid artery blood flow induced by isoproterenol (a β-adrenoceptor agonist) was reduced, whereas the response to sodium nitroprusside (a guanylate cyclase activator) was unchanged. In vitro acetylcholine-induced microvascular vasodilation was converted to a contractile response and isoproterenol elicited less relaxation after 2 hours of cardiopulmonary bypass. One hour of cerebral perfusion after cardiopulmonary bypass caused a further reduction in isoproterenol-induced relaxation but had no further effect on the cholinergically mediated response. In vitro relaxation responses to sodium nitroprusside and forskolin (an adenylate cyclase activator) were similar in all experimental groups, suggesting that second-messenger mechanisms remain intact after normothermic cardiopulmonary bypass. In conclusion, basal cerebrovascular resistance and internal carotid artery blood flow are maintained if the systemic circulation and pressure are supported with fluid administration after cardiopulmonary bypass. Agonist-induced vasodilation of cerebral microvessels to cholinergic and β-adrenoceptor stimulation are selectively impaired after normothermic cardiopulmonary bypass, whereas second-messenger mechanisms remain intact. (J Thorac Cardiovasc Surg 1996;112:450-61)

Acute massive pulmonary embolism is associated with a high mortality rate. Prompt diagnosis and treatment are mandatory for a successful outcome. Although thrombolysis is effective, it is associated with a high rate of bleeding complications. This report describes the use of emergent pulmonary embolectomy as an effective and aggressive therapeutic approach to a massive saddle pulmonary embolism in a 66-year-old woman. With the application of specific surgical techniques and good interdisciplinary cooperation, pulmonary embolectomy may serve as more than a last resort for the management of this clinically unstable and dangerous condition.

Background. Nonimmune long-term travelers to sub-Saharan Africa are at a high risk of contracting malaria. Most previous studies described risk factors and spatial distribution only in short-term travelers. This study describes the epidemiology and spatial distribution of malaria cases among expatriate healthcare workers in Equatorial Guinea. Methods. We conducted a cohort study evaluating the risk factors for malaria among healthcare personnel working in a hospital in Bata, Equatorial Guinea. Demographic data were recorded for all workers, and the spatial distribution of malaria cases within the hospital perimeters was determined. Results. During 2008 noncomplicated falciparum malaria was diagnosed in 13/102 workers (12.75%). On univariate analysis, the factors negatively associated with the risk of contracting malaria were living above the first floor and being older than 30 years. This association remained significant in multivariate analysis [hazard ratio (HR) = 0.24, 95% confidence interval [CI] = 0.06–0.91 for subjects living above the first floor and HR = 0.14, 95% CI = 0.04–0.52 for subjects above 30 years old]. Males and smokers had increased risk of contracting malaria on univariate analysis. However, this association was not significant in multivariate analysis (HR = 3.37, 95% CI = 0.87–13.1 and HR = 3.12, 95% CI = 0.83–11.75, for univariate and multivariate analysis, respectively). Low compliance with malaria prevention guidelines was observed in the study cohort. Conclusions. Living on the ground floor of apartment buildings in sub-Saharan Africa, as opposed to living on the top floors, confers an increased risk of acquiring malaria in long-term travelers with low compliance to prophylaxis. These findings should be discussed in advance with people intending to stay in sub-Saharan Africa for an extended period of time. The association between belonging to a younger age group and an increased risk of acquiring malaria, and the marginally significant increased risk of malaria in males and smokers, can probably be explained by increased exposure to malaria vectors. The compliance of healthcare workers with malaria prophylaxis is extremely low, as was previously described for other long-term residents.

Intravenous leiomyomatosis is a rare, benign neoplasm of the uterine, affecting adult women. We report two cases in whom intravenous leiomyomatosis extended through the inferior vena cava into the right heart chambers and the pulmonary artery. Both patients underwent staged operation with excision of the cardiac and primary tumour. The differential diagnosis of a right atrial mass in middle-aged women should include intravenous leiomyomatosis.

Recent years have witnessed important progress in the use of minimally invasive robotic-enhanced surgical systems in cardiac and general thoracic interventions. We report the first-ever successful use of the Zeus robotic surgical system (Computer Motion, Inc, Goleta, CA) for the excision of an anterior mediastinal mass. Proper positioning of the thoracic ports for the robotic arms to permit a wide range of movement, is the key to the application of the system for intrathoracic cage operations. Other advantages of the system include three-dimensional voice controlled imaging, low-heat surgical field, and good exposure of the structures.

Background: The number of patients awaiting heart transplantation is increasing in proportion to the waiting period for a donor. Studies have shown that coenzyme Q10 (CoQ10) has a beneficial effect on patients with heart failure. Hypothesis: The purpose of the present double‐blind, placebo‐controlled, randomized study was to assess the effect of CoQ10 on patients with end‐stage heart failure and to determine if CoQ10 can improve the pharmacological bridge to heart transplantation. Methods: A prospective double‐blind design was used. Thirty‐two patients with end‐stage heart failure awaiting heart transplantation were randomly allocated to receive either 60 mg U/day of Ultrasome™‐‐‐CoQ10 (special preparation to increase intestinal absorption) or placebo for 3 months. All patients continued their regular medication regimen. Assessments included anamnesis with an extended questionnaire based partially on the Minnesota Living with Heart Failure Questionnaire, 6‐min walk test, blood tests for atrial natriuretic factor (ANF) and tumor necrosis factor (TNF), and echocardiography. Results: Twenty‐seven patients completed the study. The study group showed significant improvement in the 6‐min walk test and a decrease in dyspnea, New York Heart Association (NYHA) classification, nocturia, and fatigue. No significant changes were noted after 3 months of treatment in echocardiography parameters (dimensions and contractility of cardiac chambers) or ANF and TNF blood levels. Conclusion: The administration of CoQ10 to heart transplant candidates led to a significant improvement in functional status, clinical symptoms, and quality of life. However, there were no objective changes in echo measurements or ANF and TNF blood levels. Coenzyme Q10 may serve as an optional addition to the pharmacologic armamentarium of patients with end‐stage heart failure. The apparent discrepancy between significant clinical improvement and unchanged cardiac status requires further investigation.

Background Video-assisted thoracoscopy with the creation of a pericardial window is a noninvasive method of pericardial drainage. It also allows an excellent view of both the pleural cavity and pericardium and the precise selection of biopsy sites. We review our 3-year experience with this technique. Methods Between January 2001 and February 2004, 18 patients (10 men, 8 women; mean age 57 years) with echocardiographically diagnosed pericardial effusion underwent video-assisted thoracoscopy at our center. Pericardial windows were created under general anesthesia and single-lung ventilation using 2 to 3 trocars. Mean operating time was 46 minutes. A right thoracic approach was used in 16 patients and a left thoracic approach in 2. Results Microbiology and virology cultures of the pericardial fluid were negative. Histologic findings were compatible with tuberculosis in 2 cases and granulocytic sarcoma, infiltrating breast carcinoma, and infiltrating nonsmall cell carcinoma in 1 case each. In the remaining patients, the histologic diagnosis was chronic or subacute nonspecific pericarditis. Talc pleurodesis was performed in 3 patients for concomitant malignant pleural effusion. In 4 patients, the pericardial effusion occurred secondary to cardiac surgery; 3 were receiving anticoagulants after valve replacement, and 1 had a heart transplant. There were no complications of the thoracoscopy technique. Conclusions Video-assisted thoracoscopic fenestration is an effective technique for pericardial drainage and biopsy. Apart from its diagnostic value, it allows the physician to fashion a pleuropericardial window for effective drainage while avoiding the complications of classic surgical procedures. Concomitant pleural and pulmonary disorders may be managed simultaneously.

Objective: The internal thoracic artery has become the conduit of choice for coronary artery bypass grafting. To avoid spasm of the artery, and increases in its diameter and flow, various vasodilators have been used either intraluminally or by topical application by different surgeons. In order to define the best vasodilating agent for preparation of the internal thoracic artery, a randomized double-blind placebocontrolled clinical study was performed in a group of patients submitted for elective coronary artery bypass grafting. Methods and results: Eighty (80) consecutive patients submitted for elective first time coronary artery bypass grafting were randomly subdivided into five treatment groups. Free flow of the left internal thoracic artery was measured using an electromagnetic flow meter. The first measurement was performed shortly after the internal thoracic artery was dissected from the chest wall and the second just prior to performing distal anastomosis to the left anterior descending coronary artery. During the time interval between the two measurements the internal thoracic artery was immersed in a special applicator tube containing 20 ml solution of one of the following drugs: papaverin 2 mg/ml, nitroglycerin 1 mg/ml, verapamil 0.5 mg/ml, nitroprusside 0.5 mg/ml, normal saline 0.9%. Results: No statistically significant differences were found between the groups in respect to age, body surface area, bypass time, cross clamping time, and time interval between the two flow measurements. Mean arterial pressure at the time of the first and second internal thoracic artery flow measurements did not show statistically significant differences either within or between the groups. In all five groups, the free flow of the internal thoracic artery increased significantly with time. However, no statistically significant differences were shown between the five groups with respect to second flow (Pa 0:2). Conclusions: Within the limits of our study design, we suggest that preparation of the LITA by topical vasodilator drugs using a special applicator tube does not result in a significantly superior free flow than placebo. q 1999 Elsevier Science B.V. All rights reserved.

A number of heparin-binding growth factors, including basic (bFGF) and acidic (aFGF) fibroblast growth factors have been shown to promote angiogenesis in vivo. In this study, we employed a sustained-release polymer extravascular delivery system to evaluate the angiogenic efficacy of a novel form of genetically modified aFGF in the setting of chronic myocardial ischemia. Fifteen Yorkshire pigs subjected to Ameroid occluder placement on the left circumflex (LCX) artery were treated with perivascularly administered aFGF in ethylene vinyl acetate (EVAc) polymer (10 μg, n = 7) or EVAc alone (controls, n = 8). Seven to nine weeks later, after coronary angiography to document Ameroid-induced coronary occlusion, all animals underwent studies of coronary flow and global and regional left ventricular function. Microsphere-determined coronary flow in the Ameroid-compromised territory was significantly increased in aFGF-treated compared with control animals, and this improvement in perfusion was maintained during ventricular pacing. Left ventricular function studies demonstrated improved global and regional function in aFGF-treated animals. We conclude that local perivascular delivery of genetically modified aFGF results in significant improvement in myocardial flow and regional and global left ventricular function.

Background The purpose of the current investigation was to determine and compare the direct effect of isoflurane on normal resistance coronary arteries and similarly sized coronary arteries in collateral-dependent (CD) circulation. A differential vasomotor effect of isoflurane might contribute to flow redistribution, either adverse or favorable, between normal and CD regions. Methods The authors used a swine model of chronic coronary occlusion. Six weeks after ameroid occluder placement around the left circumflex artery, the heart was removed. Myocardial blood flow, measured in vivo before the removal, was lower during rapid atrial pacing in the CD region than in the normally perfused region. These in vivo studies established the existence and location of CD circulation. Subepicardial microvessels, measuring approximately 100 microns, were dissected from both the CD region and the normal region. Either with or without preconstriction of the vessels with the thromboxane analogue U46619 1 microM, direct vasomotor effect of isoflurane was examined in vitro by video microscopy. In addition, vasomotor responses to endothelin-1, the endothelium-dependent dilator adenosine 5' diphosphate, and the endothelium-independent dilator sodium nitroprusside were compared between CD and normal resistance vessels. Results Isoflurane caused greater concentration-dependent constriction of the normal vessels than of the CD vessels (P < 0.05); this constrictive effect was masked by preconstriction of the vessels. Vasodilation of ADP was less in CD vessels than in normal vessels (P < 0.001), but vasodilation to sodium nitroprusside was not significantly different (P = 0.45). Vasoconstriction to endothelin-1 was greater in CD vessels than in normal vessels (P < 0.01). Conclusions The vasoconstrictive effect of isoflurane normally observed in coronary resistance vessels is impaired in resistance vessels that supply a CD area. The basis of this may be related to endothelial dysfunction.

Background. The purpose of this study was to determine whether cerebral cortical microvascular responses to platelet-derived vasoactive substances are altered after normothermic cardiopulmonary bypass (CPB), and whether these alterations are modified by moderate hypothermia. Methods. Pigs were placed on normothermic CPB (37°C) for 2 hours and then perfused off CPB with normothermic blood for either 15 minutes (n = 8) or 60 minutes (n = 6). Another group was placed on moderately hypothermic CPB (25°C) for 2 hours and then perfused off CPB at 37°C for 15 minutes (n = 6). Alpha-stat pH management was used. In vitro responses of isolated cortical cerebral arterioles (90 to 170 μ m internal diameter) to platelet-derived vasoactive substances were examined in a pressurized no-flow state with video-microscopy. Microvessels from noninstrumented pigs (n = 14) were used as controls for in vitro studies. Results. Cerebrovascular resistance and internal carotid artery blood flow were similar 15 minutes after CPB in both normothermic and hypothermic groups. However, relaxations of microvessels to adenosine 5′ diphosphate or serotonin were reduced in vessels from both groups. One hour of after CPB cerebral perfusion did not change this pattern of altered vascular reactivity. Hypothermia caused a partial but significant reduction in impairment of responses to adenosine 5′ diphosphate and serotonin. Microvascular relaxation to the endothelium-independent agent sodium nitroprusside and contraction to a thromboxane A 2 analog were similar in all experimental groups, suggesting normal vascular smooth muscle responsiveness. Conclusions. This study demonstrates that normothermic extracorporeal circulation reduces endothelium-dependent relaxation responses to products of platelet activation in the cerebral microcirculation. Moderate hypothermia attenuates the CPB-induced impairment of endothelium-dependent relaxation, but has no effect on baseline cerebral blood flow after rewarming.

Recombinant activated factor VII (rFVIIa) (NovoSeven®; Novo Nordisk, Denmark) was developed primarily for the treatment of bleeding episodes in hemophilic patients. Little information is available on the use of rFVIIa in other situations, such as intractable postsurgical or post-traumatic bleeding. In the field of cardiac surgery, only a very few cases of treatment with rFVIIa are described. Because of the difficulty in performing randomized trials in this setting, information based on case studies is very valuable.