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Biomedical subjects

R Ascione

Publications and source records attributed to R Ascione.

At least 37 records · Page 2Linked to original sources
PubMed2000

Effect of cardiopulmonary bypass on pulmonary gas exchange: a prospective randomized study.

BACKGROUND: Conventional coronary artery bypass surgery is associated with postoperative pulmonary dysfunction. Inflammation due to cardiopulmonary bypass has been regarded as one of the main causes. In this study, we investigated the effect of coronary revascularization with or without cardiopulmonary bypass on pulmonary function. METHODS: Fifty-two patients (40 male, mean age 60.1 years) were prospectively randomized to undergo coronary revascularization via median sternotomy, with or without normothermic cardiopulmonary bypass. Alveolar-arterial oxygen gradients were measured before and after induction of anesthesia, postoperatively in the intensive care unit during mechanical ventilation and 6 hours after tracheal extubation. The techniques of anesthesia and mechanical ventilation were standardized throughout. RESULTS: Patient characteristics were similar in the two groups. The alveolar-arterial oxygen gradients increased progressively throughout the perioperative period, with no significant differences in the two groups at any time during the study. CONCLUSIONS: Myocardial revascularization with or without cardiopulmonary bypass caused a similar degree of pulmonary dysfunction, as assessed by alveolar-arterial oxygen gradient. Our study suggests that the deterioration in pulmonary gas exchange associated with cardiac surgery is due to factors other than the use of cardiopulmonary bypass.

Body Temperature↗
PubMed2000

Serum S-100 protein release and neuropsychologic outcome during coronary revascularization on the beating heart: a prospective randomized study.

OBJECTIVES: Our purpose was to establish whether coronary revascularization on the beating heart without cardiopulmonary bypass is less harmful to the brain than conventional surgery with cardiopulmonary bypass as indicated by measures of cognitive function or by changes in serum concentrations of S-100 protein, a recognized biochemical marker of cerebral injury. METHODS: We conducted a prospective randomized trial in which the assessors of the outcome measures were blind to the treatment received. Sixty patients without known neurologic abnormality, undergoing coronary revascularization, were prospectively randomized to 1 of 2 groups: (1) cardiopulmonary bypass (32 degrees C-34 degrees C) and cardioplegic arrest (on pump) with intermittent antegrade warm blood cardioplegia or (2) surgery on the beating heart (off pump). Neuropsychologic performance was assessed before and 12 weeks after the operation. Serum S-100 protein concentration was measured at intervals up to 24 hours after the operation. RESULTS: The groups had similar preoperative characteristics. There were no deaths or major neurologic complications in either group, nor was there any difference between groups in the chosen index of neurologic deterioration. Serum S-100 protein concentrations were higher in the on-pump group at 30 minutes, but any such difference between groups had disappeared 4 hours later. The extent of the changes in S-100 protein was unrelated to the index of neuropsychologic deterioration. CONCLUSIONS: The changes in S-100 protein concentration suggest that the brain and/or blood-brain barrier may be more adversely affected during coronary artery surgery with cardiopulmonary bypass than during surgery on the beating heart, but that this may not be reflected in detectable neuropsychologic deterioration at 12 weeks.

Aged↗
PubMed2000

Emergency repair of type A aortic dissection in type IV Ehlers-Danlos syndrome.

Ehlers-Danlos syndrome type IV is a distinctive syndrome in which thin and fragile skin, premature ageing, bruising and scarring are combined with lethal or life-threatening arterial weakness. Aortic rupture either at the aortic root and arch, or sometimes lower down the artery, are particularly characteristic. Even quite minor injury can produce dangerous vascular tearing and damage. Technical difficulties encountered in arterial repair or venous ligature are particularly worrying. The authors report the treatment of a ruptured type A aortic dissection associated with Ehlers-Danlos syndrome where the extreme fragility of the tissues and tendency to bleed posed a difficult task for the surgeon.

Adult↗
PubMed2000

Combined coronary artery and abdominal aortic surgery without cardiopulmonary bypass.

To determine the effects of beating heart surgery on patients undergoing simultaneous coronary artery bypass grafting and abdominal aortic surgery, we performed such surgery on 20 patients (mean age, 64.55+/-796 SD years). Abdominal aortic disease was defined as an abdominal aortic aneurysm larger than 5 cm in diameter or as end-stage aortic occlusive disease. Hemodynamic measurements, inotropic requirements, and incidence of perioperative myocardial infarction and arrhythmias were recorded, as were subsystem clinical outcomes, length of intensive care unit and hospital stays, blood loss, and transfusion requirements. There was no incidence of death, perioperative myocardial infarction, stroke, or acute renal failure. The mean number of grafts per patient was 1.95+/-0.69. Only 4 minor postoperative complications were observed: three patients (15%) had evidence of supraventricular tachyarrhythmias, and 1 patient (5%) had chest infection that required a longer-than-average intubation period. Six patients (30%) required minimal-to-moderate inotropic support. The mean blood loss was 673+/-246.8 mL and transfusion requirements were low. The mean intensive care unit and hospital lengths of stay were 2. 12+/-0.33 days and 708+/-1.44 days, respectively. Clinical follow-up (mean, 10 months) showed all patients to be in New York Heart Association functional class I or II with no late cardiac or abdominal events. We conclude that simultaneous coronary artery bypass grafting and abdominal aortic surgery on the beating heart is safe and effective, and has a low perioperative clinical morbidity rate. To our knowledge, ours is the 1st report on this procedure. Larger studies with longer follow-up are needed.

Aged↗
PubMed1999

Integrated left anterior small thoracotomy and angioplasty for coronary artery revascularization.

BACKGROUND: The minimal access surgical technique of a left anterior small thoracotomy (LAST) for coronary artery bypass grafting is now well established. This procedure however, does not allow multivessel revascularization. We present our early experience of an integrated approach using LAST and percutaneous transluminal coronary angioplasty (PTCA), either staged or simultaneous. METHODS: Eighteen patients (14 men and 4 women), mean age 63 (range 35-87 years) were treated. Four patients underwent simultaneous LAST and PTCA revascularization. The remaining 14 patients were first treated with the LAST procedure, followed 1-3 days later by angioplasty. Angiographic assessment was carried out before PTCA and at 6 months after. RESULTS: The 14 patients who underwent the staged procedure all had patent left internal mammary artery/left anterior descending coronary artery grafts. Angioplasty was performed on 21 vessels (10 stented) with good early angiographic results. All patients were extubated early, mean intensive care stay was 14.7 + 9.4 hours, mean hospital stay was 5 + 1.5 days. All patients were symptom free at 18 months follow-up. CONCLUSIONS: Staged LAST and angioplasty is a safe and effective approach suitable for patients in whom there are contraindications to the use of extracorporeal circulation. The simultaneous approach is limited by the risk of bleeding associated with the use of anticoagulation when coronary stenting is required.

Adult↗
PubMed1999

On-pump versus off-pump coronary revascularization: evaluation of renal function.

BACKGROUND: Coronary revascularization with cardiopulmonary bypass has the potential risk of renal dysfunction related to the nonphysiologic nature of cardiopulmonary bypass. Recently, there has been a revival of interest in performing myocardial revascularization on the beating heart and we investigated whether this prevents renal compromise. METHODS: A prospective, randomized, controlled trial was performed in 50 patients (45 males, mean age 61+/-3.7 years) undergoing elective coronary artery bypass grafting. Patients were randomly assigned to conventional revascularization with cardiopulmonary bypass (on pump) or beating heart revascularization (off pump). Glomerular and tubular function were assessed up to 48 hours postoperatively. RESULTS: There were no deaths, myocardial infarctions or acute renal failure in either group. Glomerular filtration as assessed by creatinine clearance and the urinary microalbumin/creatinine ratio was significantly worse in the on pump group (p < 0.0004 and 0.0083, respectively). Renal tubular function was also impaired in the on pump group as assessed by increased N-acetyl glucosaminidase activity (p < 0.0272). CONCLUSIONS: These results suggest that off pump coronary revascularization offers a superior renal protection when compared with conventional coronary revascularization with cardiopulmonary bypass and cardioplegic arrest in first time coronary bypass patients.

Acetylglucosaminidase↗
PubMed1999

Economic outcome of off-pump coronary artery bypass surgery: a prospective randomized study.

BACKGROUND: Emphasis on cost containment in coronary artery bypass surgery is becoming increasingly important in modern hospital management. The revival of interest in off-pump (beating heart) coronary artery bypass surgery may influence the economic outcome. This study examines these effects. METHODS: Two hundred patients undergoing first-time coronary artery bypass surgery were prospectively randomized to either conventional cardiopulmonary bypass and cardioplegic arrest or off-pump surgery. Variable and fixed direct costs were obtained for each group during operative and postoperative care. The data were analyzed using parametric methods. RESULTS: There was no difference between the groups with respect to pre- and intraoperative patient variables. Off-pump surgery was significantly less costly than conventional on-pump surgery with respect to operating materials, bed occupancy, and transfusion requirements (total mean cost per patient: on pump, $3,731.6+/-1,169.7 vs off-pump, $2,615.13+/-953.6; p < 0.001). Morbidity was significantly higher in the on-pump group, which was reflected in an increased cost. CONCLUSIONS: Off-pump revascularization offers a safe, cost-effective alternative to conventional coronary revascularization with cardiopulmonary bypass and cardioplegic arrest.

Aged↗
PubMed1999

Beating versus arrested heart revascularization: evaluation of myocardial function in a prospective randomized study.

OBJECTIVE: Conventional coronary artery bypass grafting (CABG) is both safe and effective. Nevertheless, the use of cardiopulmonary bypass (CPB) and cardioplegic arrest are associated with several adverse effects. Over the last 2 years there has been a revival of interest in performing CABG on the beating heart. In this prospective randomized study we evaluated the efficacy and safety of on and off pump coronary revascularization on myocardial function. METHODS: Eighty patients (65 males, mean age 61+/-9.7 years) undergoing first time CABG were prospectively randomized to: (i) conventional revascularization with CPB at normothermia and cardioplegic arrest with intermittent warm blood cardioplegia (on pump) or (ii) beating heart revascularization (off pump). Troponin I (Tn I) release was serially measured as a specific marker of myocardial damage. Haemodynamic measurements as well as inotropic requirement, incidence of arrhythmia and postoperative myocardial infarction were also recorded. RESULTS: There were no significant differences between the two groups in terms of age, sex, extent of disease, left ventricular function and number of grafts. There were no deaths or intraoperative myocardial infarctions in either group. Tn I release was constantly lower in the off pump group and this was significant at 1, 4, 12 and 24 h postoperatively. Furthermore, in this group there was a significantly reduced incidence of arrhythmias. Inotropic requirements were less in the off pump group but this did not reach statistical significance. CONCLUSION: These results suggest that off pump coronary revascularization is a safe and effective strategy for myocardial revascularization. Myocardial injury as assessed by Tn I release is also reduced when compared with conventional coronary revascularization with CPB and cardioplegic arrest.

Aged↗
PubMed1999

Evaluation of myocardial metabolism and function during beating heart coronary surgery.

Coronary artery bypass surgery on the beating heart either via a left anterior small thoracotomy (LAST) or a median sternotomy is becoming increasing popular world-wide. Concern still remains about the potential for a temporary regional myocardial ischaemia associated with the stabilisation and occlusion of the coronary during construction of the anastomosis. This review summarises the results of a series of studies intended to evaluate the effect of beating heart coronary revascularization on myocardial function, myocardial tissue injury and clinical outcome.

Biomarkers↗
PubMed1999

Intraoperative localisation and management of coronary artery fistula using transesophageal echocardiography.

Coronary artery fistula is a rare congenital malformation that can be complicated by intracardiac shunts, endocarditis, myocardial infarction, coronary aneurysm and sudden death. Clinical symptomatology depends upon the underlying anatomy and the size of the fistulous connection between the left or right side of the heart. We report the successful management of a giant right coronary artery with fistulization into the right atrium. Intraoperative transesophageal echocardiography with colour flow Doppler was used for precise location of the fistulous communication, selective demonstration of vessels feeding the fistula and documentation of abolition of fistulous flow all without the need for cardiopulmonary bypass. Furthermore the effect of shunt occlusion on regional wall motion was documented which facilitated the successful ligation of the fistula.

Adult↗
PubMed1999

Abdominal abscess: late complication after gastroepiploic coronary artery bypass grafting.

The gastroepiploic artery is widely used an arterial conduit during coronary artery revascularisation surgery. We report an unusual complication of a 56-year-old man who developed a late intra-abdominal abscess extending into the mediastinum adjacent to the right ventricle more than 2 years after surgery. This was managed with percutaneous drainage and the patient made a full recovery. The case illustrates the potential problems associated with harvesting of this artery and the need for careful haemostasis.

Abdominal Abscess↗
PubMed1998

Metabolic differences between hearts of patients with aortic valve disease and hearts of patients with ischaemic disease.

The hypertrophic hearts of patients with aortic valve disease are likely to have metabolic demands different from hearts with ischaemic disease. In this study we measured the myocardial concentration of ATP, ADP, lactate and 16 different amino acids in left ventricular biopsies collected from patients with aortic valve disease and from patients with ischaemic heart disease. Compared to hearts with ischaemic disease, hypertrophic hearts had significantly higher concentrations of ATP, but lower concentrations of lactate, branched-chain amino acids and alanine. These differences have important implications for energy metabolism and protein turnover in the two pathologies.

Adenosine Diphosphate↗
PubMed1998

Warm blood cardioplegia reduces the fall in the intracellular concentration of taurine in the ischaemic/reperfused heart of patients undergoing aortic valve surgery.

The effect of cold and warm intermittent antegrade blood cardioplegia, on the intracellular concentration of taurine in the ischaemic/reperfused heart of patients undergoing aortic valve surgery, was investigated. Intracellular taurine was measured in ventricular biopsies taken before institution of cardiopulmonary bypass, at the end of 30 min of ischaemic arrest and 20 min after reperfusion. There was no significant change in the intracellular concentration of taurine in ventricular biopsies taken after the period of myocardial ischaemia in the two groups of patients (from 10.1 +/- 1.0 to 9.6 +/- 0.9 mumol/g wet weight for cold and from 9.3 +/- 1.3 to 10.0 +/- 1.3 mumol/g wet weight for warm cardioplegia, respectively). Upon reperfusion however, there was a fall in taurine in both groups but was only significant (P < 0.05) in the group receiving cold blood cardioplegia (6.9 +/- 0.8 mumol/g wet weight after cold blood cardioplegia versus 8.0 +/- 0.8 mumol/g wet weight following warm blood cardioplegia). Like taurine, there were no significant changes in the intracellular concentration of ATP after ischaemia in the two groups of patients (from 3.2 +/- 0.32 to 2.95 +/- 0.43 mumol/g wet weight for cold and from 2.75 +/- 0.17 to 2.62 +/- 0.21 mumol/g wet weight for warm cardioplegia, respectively). However upon reperfusion there was a significant fall in ATP in both groups with the extent of the fall being less in the group receiving warm cardioplegia (1.79 +/- 0.19 mumol/g wet weight for cold and 1.98 +/- 0.27 mumol/g wet weight for warm cardioplegia, respectively). This work shows that reperfusion following ischaemic arrest with warm cardioplegia reduces the fall in tissue taurine seen after arrest with cold cardioplegia. Accumulation of intracellular sodium provoked by hypothermia and a fall in ATP, may be responsible for the fall in taurine by way of activating the sodium/taurine symport to efflux taurine.

Adenosine Triphosphate↗
PubMed1998

Bioprosthetic replacement after bioprosthesis failure: a hazardous choice?

BACKGROUND: Following bioprosthetic failure, replacement is usually done with mechanical valves to avoid repeated reoperations. METHODS: From 1986 to 1996 we operated on 130 patients with bioprosthetic failure, implanting a new bioprosthesis; this group included patients with contraindication to anticoagulation, tricuspid replacement, and specific patient requests. Mean age was 63+/-8 years. RESULTS: The perioperative mortality was 13.8%. At 10 year follow-up the actuarial estimate of survival was 77.4%+/-6.6%. Freedom from structural valve deterioration was estimated at 81.8%+/-6.3%. Freedom from a third operation was estimated at 85.5%+/-5.2%. No patient was permanently anticoagulated. Freedom from thromboembolism was estimated at 91.5%+/-4%, and there were no hemorrhages. Freedom from cardiac-related deaths was estimated at 85.7%+/-5%. CONCLUSIONS: This group of patients received the first valve between 1976 and 1986; the range of the cumulative follow-up reaches 20 years, and the extended survival compares favorably with survival of mechanical valves.

Actuarial Analysis↗
PubMed1998

The end of the cold era: from intermittent cold to intermittent warm blood cardioplegia.

BACKGROUND: A major reduction in the energy demand of the myocardium results from the electromechanical arrest, and cooling contributes to a lesser degree to this reduction. It is from this assumption that strategies of myocardial protection, utilizing warm blood cardioplegic induction, followed by cold cardioplegia with terminal warm reperfusion before removal of the aortic cross clamp, became established as optimal myocardial protection. Continuous normothermic perfusion 'closed the loop' by avoiding myocardial ischemia and linking warm induction and terminal reperfusion. A series of laboratory and clinical data confirmed the benefits of warm heart surgery on myocardial function and metabolism. The disadvantages of continuous warm blood cardioplegia including disturbance of the operative field, led surgeons to administer warm hyperkalaemic blood intermittently as a new cardioplegic strategy. METHODS: This review examines the laboratory and clinical data with reference to the intermittent warm blood cardioplegia, to establish its experimental basis and place in clinical practice. CONCLUSIONS: Experimental observation and clinical application have established intermittent warm blood cardioplegia as a practical, effective and cheap myocardial protection technique, particularly with reference to coronary artery surgery.

Animals↗
PubMed1997

Intermittent warm blood cardioplegia preserves myocardial beta-adrenergic receptor function.

BACKGROUND: Left ventricular dysfunction is frequently observed in patients after hypothermic cardioplegic arrest, and often inotropic intervention is necessary for patients to be successfully weaned from cardiopulmonary bypass (CPB). A myocardial beta-adrenergic receptor (beta AR) desensitization has been noted to occur after hypothermic CPB in patients undergoing coronary artery bypass grafting. This randomized study was undertaken to determine the effect of cardioplegic solution temperature on cardiac beta ARs. METHODS: Two groups of patients (20 patients in each) scheduled for elective coronary artery bypass grafting underwent CPB with either intermittent warm or cold blood cardioplegia. The density of the beta ARs, the proportion of beta 1- to beta 2-adrenergic receptors, and the beta AR coupling capacity to adenylate cyclase were determined in specimens of the right atrial tissue at baseline, during CPB, and after discontinuation of CPB. Plasma concentrations of catecholamines were also measured in both arterial and coronary sinus samples. RESULTS: In both cardioplegia groups, no significant modification in either the beta AR density or the proportion of beta 1- to beta 2-adrenergic receptors was detected. However, a significant decrease in adenylate cyclase activity after stimulation with isoproterenol was observed in the cold blood cardioplegia group during CPB (p < 0.01) and 30 minutes after its discontinuation (p < 0.05). Moreover, a significant decrease in adenylate cyclase activity during CPB was detected in this group after stimulation with sodium fluoride (p < 0.05), but this pattern was found to be completely reversed by 30 minutes after discontinuation of CPB. No modification in the basal or stimulated adenylate cyclase activity was observed in the warm blood cardioplegia group during or after CPB. CONCLUSIONS: Our results confirm the finding from previous studies of a cardiac beta AR desensitization after hypothermic cardioplegic arrest, and provide evidence of the advantages of intermittent warm blood cardioplegia in preserving the autonomic sympathetic function of the heart.

Adenylyl Cyclases↗