Limited access left thoracotomy for reoperative coronary artery disease: on or off pump.

Between 1971 and 1988 left thoracotomy was performed on pump for selected reoperations. Since 1993, 92 patients were operated on with a limited approach and an increased number of cases were done off pump (70 patients). The purpose of this paper is to describe the transition of our operative techniques from on pump to off pump for reoperative coronary patients. From 1995 to 1999, 22 patients (Group 1) were operated on pump and 70 patients (Group II) off pump; 86 of 92 (93.5%) had reoperations. The demographic data were similar in these two groups regarding age, gender, ejection fraction, and total number of grafts performed. In this study 92 patients had a crude mortality of 4.3%. Limited access thoracotomy provides safer reoperation than previously (1971-1988) with an improved on or off pump (4.5% vs. 4.3%) mortality, compared to the on pump mortality of 10% between 1971-1988. Off-pump operations are performed with increasing frequency and with the same risk and less postoperative complications.

Conversion to cardiopulmonary bypass in off-pump coronary artery bypass grafting: its effect on outcome.

The surgical outcome of patients requiring conversion to cardiopulmonary bypass (CPB) during myocardial revascularization using the less invasive surgical approach (LISA) was assessed. The LISA was recently introduced as a technique for complete myocardial revascularization without CPB. It combines avoidance of CPB with the versatility of a median sternotomy for access to all coronary vessels. We have previously demonstrated reduced risk-adjusted mortality and complications in off-CPB coronary artery bypass grafting (CABG) using LISA compared to standard myocardial revascularization. From January to December 1997, 1210 patients underwent isolated CABG at our institution. Of these patients, 832 (63%) were scheduled as on-CPB cases and 378 (37%) as off-CPB. Of the off-CPB patients, 48 were converted to CPB. Team A surgeons used LISA as their primary strategy for CABG whereas team B surgeons used off-CPB CABG in selected patients. Conversions were divided in three classes: Class I patients were converted when the surgeon considered complete revascularization impossible off-CPB; Class II patients were converted due to hemodynamic instability during the procedure; and Class III patients were converted due to graft malfunction, determined by flow measurements or clinical evidence. There were four deaths. All had perioperative infarctions and required intra-aortic balloon pump (IABP). Conversion to CPB occurred in up to 25% of patients scheduled for off-CPB CABG. When off-CPB cases are done using the comprehensive LISA technique and modern technology, conversion rates may be reduced to 11%. Conversion is in general well tolerated except when it is instituted for graft malfunction combined with hemodynamic instability or collapse.

Dissecting aortic aneurysm in pregnant women without Marfan disease.

Dissection of the young women without Marfan disease is related, in most instances, to pregnancy. The structural changes in the arterial wall that occur during pregnancy may predispose women to this complication of pregnancy. In this study, two young women, who had none of the characteristics of Marfan's syndrome, were operated upon for dissection of the ascending aorta. The first patient was in the 35th week of gestation and a cesarean section was performed prior to replacement of the ascending aorta. In the second patient, diagnosis of dissection and severe aortic regurgitation occurred in the postpartum period. Knowledge of this albeit relatively rare complication of pregnancy may assist the clinician in diagnosing and referring patients early for surgical treatment that, in most instances, may save the lives of both mother and fetus.

Safety precautions in the management of patients with pacemakers when electrocautery operations are performed.

The hazards related to ten patients who underwent 11 urologic surgical procedures during a 36 month period were taken into consideration. Electrocautery was used in all instances and there were no complications. All of the pacemakers were preset for ventricular pacing and sensing inhibited or multiprogrammable and were reprogrammed during the operation to ventricular pacing fixed rate mode or magnet mode, with very satisfactory outcome. To avoid life-threatening situations arising from pacemaker inhibition or ventricular fibrillation during cautery for transuretheral resection, three basic factors were considered: 1, appropriate type of pacemaker; 2, the proper grounding of all medical electronic equipment used during the procedure, and 3, the directing of the complete flow of the electrocautery circuits substantially below the level of the pacemaker unit.

Total excision of a giant angiolipoma of chest wall with A-V malformation and with the use of an autotransfusion system.

An 18 year old girl suffering from a giant angiolipoma of back and chest wall with A-V malformation underwent total excision of the tumor in 4 stages. The first two stages included surgical ligation of the arterial blood supply to the tumor. In the third and fourth stages the tumor was resected with the use of an autotransfusion system. The last stage was complicated with massive bleeding and disseminated intravascular clotting. Control of bleeding was achieved by the use of autotransfusion system, right thoracotomy and massive transfusion of blood and its components. After long convalescence period associated with renal and respiratory failure the patient recovered completely without sequellae. This case demonstrates the complexity associated with the treatment of these rare tumors.

Systemic haemodynamic actions of pimobendan (UD-CG 115 BS) and its O-demethylmetabolite UD-CG 212 Cl in the conscious pig.

The cardiovascular effects of the pyridazinone-derivatives pimobendan and its O-demethylmetabolite UD-CG 212 Cl (2-(4-hydroxy-phenyl)-5-(5-methyl-3-oxo-4,5-dihydro-2H-6-pyridazinyl) benzimidazole HCl) were studied in conscious pigs, employing consecutive intravenous 10 min infusions of 10, 25, 50 and 100 micrograms kg-1 min-1 and 2, 4 and 8 micrograms kg-1 min-1 respectively. Pimobendan caused dose-dependent increases in LVdP/dtmax (up to 115%) and heart rate (up to 30%), while cardiac output was slightly elevated (up to 15%) and stroke volume decreased by 12%. Left ventricular end-diastolic pressure decreased in a dose-related manner from 8.7 +/- 1.0 mmHg to 2.7 +/- 1.7 mmHg. Mean arterial blood pressure was not significantly affected because systemic vascular resistance decreased dose-dependently up to 15%. After beta-adrenoceptor blockade, the pimobendan-induced increases in heart rate and cardiac output were attenuated and the increase in LVdP/dtmax almost abolished. The responses of left ventricular end-diastolic and mean arterial blood pressure, systemic vascular resistance and stroke volume were not modified. UD-CG 212 Cl caused dose-related increases in LVdP/dtmax (up to 100%) and heart rate (up to 25%). Cardiac output was minimally elevated (up to 8%) as stroke volume decreased dose-dependently up to 15%. As systemic vascular resistance decreased up to 12%, mean arterial blood pressure was slightly reduced (5%). Left ventricular end-diastolic blood pressure decreased dose-dependently from 9.0 +/- 0.8 mmHg to 3.8 +/- 1.3 mmHg. After beta-adrenoceptor blockade, the UD-CG 212 Cl-induced increases in heart rate and LVdP/dtmax were attenuated and almost abolished and amounted up to 15% and 20%, respectively. The responses of the other systemic haemodynamic parameters were not significantly modified. We conclude that pimobendan and UD-CG 212 Cl are compounds with marked positive inotropic and venodilator properties in the conscious pig. The attenuation of the inotropic effects by pretreatment with propranolol strongly suggests that, in the conscious pig, the beta-adrenergic system is significantly involved in the positive inotropic actions. The lack of effect of beta-adrenoceptor blockade on the vasodilator responses to both compounds suggest a mechanism not related to beta-adrenergic activity.

Cardiovascular effects of UD-CG 212 CL, a metabolite of pimobendan, in anaesthetized pigs.

Systemic and regional haemodynamic effects of UD-CG 212 CL (0.5-16 micrograms X kg-1 X min-1), the major metabolite of the vasodilator and cardiotonic drug pimobendan, were studied in anaesthetized pigs. The drug caused a dose-dependent decrease in left ventricular (LV) end-diastolic and arterial blood pressures while it increased systemic vascular conductance, heart rate and maxLVdP/dt. The decrease in LV end-diastolic pressure was observed at lower plasma concentrations than the increase in systemic vascular conductance. Cardiac output tended to decrease but statistical significance was achieved only with the highest concentration. These effects of UD-CG 212 CL were not altered by the blockade of beta-adrenoceptors with propranolol. The vasodilator action of UD-CG 212 CL was noticed in several organs but the effects were relatively more marked (in decreasing order of magnitude) in the adrenals, kidneys, gastrointestinal tract, brain and LV epicardium. Since both arterial pressure and cardiac output decreased, the blood flow increased significantly only in the adrenals and decreased moderately in the spleen, LV endocardium and skeletal muscles. The effects of UD-CG 212 CL on the renal and skeletal muscle haemodynamics were different from those of pimobendan, which causes vasodilatation in the skeletal muscles but not in the kidneys. The results of this study show that, like the parent compound pimobendan, UD-CG 212 CL has independent cardiotonic and vasodilator actions; the latter being more pronounced on the venous side. However, the contribution of this metabolite to the overall pharmacological activity of pimobendan appears to be limited.

Late partial tamponade of the right atrium. A case report.

An unusual case of late partial tamponade of the right atrium is reported in a patient 35 days after aortic valve replacement. Chest x-rays, echocardiograms and ECG were not helpful. The diagnosis was made by emergency bedside right heart catheterization which showed a 7 cm H2O gradient between the junction of the superior vena cava and right atrium and also a 12 cm H2O pressure difference between the femoral vein and the right atrium with a normal capillary wedge pressure. Re-thoracotomy with evacuation of blood clots and control of bleeding points improved the hemodynamics dramatically. However the patient succumbed 3 weeks later due to irreversible brain damage. This is thought to be the first report of a late partial right atrial tamponade in the English medical literature.

Acute hepatic failure after open-heart surgery in children.

Acute hepatic failure (AHF) combined with acute renal failure (ARF) is a well-known complication of open-heart surgery in adults. The occurrence of this complication in two children after open-heart surgery for correction of congenital heart disease is reported. Hypotension occurred during the operation and was treated by catecholamine vasopressors. AHF set in during the postoperative course; it was manifested by impaired consciousness, hypoglycemia, hyperbilirubinemia, hyperammonemia, elevated liver enzymes and prolongation of the prothrombin time with failure of hemostasis. ARF also developed in both children. One of the patients survived the acute episode of hepatic failure. The importance of early diagnosis, routine close monitoring, and appropriate selection of vasopressors is emphasized.

Closed pericardial drainage for relief of pericardial tamponade.

The method of continuous catheter drainage for pericardial tamponade as used in 108 patients is described. The efficacy of this procedure in relieving tamponade resulting from a variety of diseases is demonstrated. Blood clot in the pericardium probably constitutes a contraindication to catheter drainage.

Repair of coarctation of the aorta in the first three months of life.

Coarctation of the aorta was surgically treated in 28 infants (16 male, 12 female) aged 2 days-3 months, with 19 younger than 1 month. Body weight at operation was 1.6-4.2 (mean 2.8) kg. 3 infants had coarctation alone, 10 had a wide patent ductus arteriosus as the only associated anomaly and 15 had a variety of other anomalies. Resection with end-to-end anastomosis was performed in only one case, while 21 underwent subclavian flap aortoplasty and six patch graft aortoplasty. Additional procedures were banding of the pulmonary artery in five cases and open aortic commissurotomy in one case. The early mortality was 10.7% (3 infants) and three more died later. Further cardiac surgery was subsequently performed on four of the infants. Of the 22 survivors, two had significant recurrence of coarctation which, however, was successfully corrected in one case. The blood pressure was within normal limits in all survivors, except those with recoarctation.

Pregnancy after valve replacement with porcine xenograft prosthesis.

The course of 22 pregnancies in 11 women undergoing heart valve replacement with a porcine xenograft is reported. All of the pregnancies treated with warfarin were interrupted by induced abortion. Of the 11 pregnancies treated with dipyridamole which were not interrupted by induced abortion, fetal wastage occurred in five. There was no fetal wastage among three patients who were not treated by any kind of anticoagulant. A review of the literature revealed that fetal complications among patients with the mechanical prosthetic valve are significantly higher compared with patients with bioprosthetic valves. There was no maternal hemorrhagic or thromboembolic event in patients with bioprosthetic valves. Delivery after porcine xenograft insertion is safe provided that the patient is in good cardiac condition and does not require warfarin treatment.

Use of the Shaw Scalpel in pacemaker operations.

Pacemaker carriers are at risk when undergoing operations involving the use of diathermy. The Shaw Scalpel utilizes a method by which the cutting edge of the blade is heated to a selected temperature that seals blood vessels as they are cut. No electrical currents are passed to or through the patient and there is no sparking or electrical arcing to the tissue. This apparatus was used as the sole method of thermal coagulation in 20 patients undergoing replacement of pacemaker batteries.

Prosthetic valve replacement in infants and children.

A review of 41 children from 10 months to 16 years of age who had a valve replacement between the years 1966 to 1981 is reported. Sixty-one per cent of the valve deformities were rheumatic and 39% congenital. Twenty-two children had the mitral valve replaced, 14 had an aortic valve and 5 had both aortic and mitral valve replacement. There was a hospital mortality of 9.7% and only one later death during a mean follow up period of 6.75 years. Three children have required a second mitral valve replacement. Thrombo-embolic episodes were encountered in 4 children. The special problems of valve replacement in infants and children are discussed.

Calcification of a porcine valve xenograft during pregnancy--a case report and review of the literature.

A 20-year-old woman required urgent replacement of a calcified prosthetic mitral porcine xenograft with a mechanical one during the 32nd week of pregnancy. Five weeks later the patient delivered a normal child. Following delivery the patient refused oral anticoagulant treatment and 7 months later she underwent emergency removal of a prosthetic valve thrombus. Six months later, still refusing anticoagulant treatment, she died of cerebral embolization. We suggest that the replacement of a degenerated biologic valve with another biologic valve should be considered in patients who refuse anticoagulant treatment and that patients with prosthetic xenografts should be kept under close medical follow-up, including echocardiography because of possible accelerated xenograft failure during and/or following pregnancy.

A simple method for insertion of a left atrial catheter in congenital heart disease.

A relatively simple and safe method is described for the insertion of a left atrial pressure line in patients undergoing operation for repair of congenital heart defects. This method has been utilized successfully in 12 patients undergoing repair of a ventricular septal defect and tetralogy of Fallot.

Coarctation of the aorta in infancy.

Twenty-five infants under 1 year of age (mean weight 3.4 kg) underwent repair of coarctation of the aorta between the years 1965 and 1982. Three patients had coarctation only, three had coarctation with patent ductus arteriosus (PDA), and 19 had associated intracardiac anomalies. Eleven patients underwent resection of the aorta and end-to-end anastomosis. Eight had subclavian flap arterioplasty, five had patch graft arterioplasty, and one had subclavian-to-aortic anastomosis. Additional procedures were performed on seven patients: banding of the pulmonary artery on one, repair of total anomalous pulmonary venous drainage on one, mitral valve replacement on one, aortic valvotomy on one, and aortic valvotomy plus pulmonary artery banding on one. Twenty-one survived the operation. All patients who died had associated intracardiac anomalies. The 21 survivors have been followed from 3 months to 13 years, with three late deaths that were associated with intracardiac anomalies. Five of the survivors underwent additional second operations: one had repair of the re-coarctation, one had replacement of the prosthetic mitral valve, one had aortic valvotomy, and two had pulmonary artery debanding and closure of a ventricular septal defect. Two of the 18 surviving patients have mild hypertension associated with a residual gradient. The others are in good health.

Myocardial protection in infant open heart surgery.

Myocardial protection was evaluated in 2 groups of 5 infants each undergoing correction of either tetralogy of Fallot (TOF) or subcristal ventricular septal defect (VSD). In group A, profound hypothermia and total circulatory arrest (PHTCA) was utilized. In group B, profound hypothermia and total circulatory arrest combined with potassium cardioplegia (PHTCA + K) was the method of protection used. The analysis was carried out by sequential measurements of clinical, electrocardiographic, enzymatic (CK-MB) and ultrastructural parameters. There were no operative deaths. One infant had a second operation for recurrent VSD. The average anoxic time was 35.4 min in group A (PHTCA) and 32.6 min in group B (PHTCA + K). Analysis of our data demonstrated that when potassium cardioplegia was added to PHTCA, there was less intraoperative myocardial damage according to physiological, ultrastructural and biochemical parameters than when profound hypothermia and total circulatory arrest was applied alone.