Evolution of surgical trends in congenital heart disease: a population based study

The aim of this study was to establish surgical trends in patients with congenital heart disease operated on between 1947 and 1997 in a population based study. All patients diagnosed as having congenital heart disease, born in Malta up to 1995 inclusive and operated for congenital heart disease up to 1997 inclusive were included. Analysis was carried out for lesions operated, age at surgery, operative centre and mortality rates, in the setting of a regional hospital providing congenital heart disease diagnostic and follow-up services for all Malta. Increasingly more operations for cardiac malformations are being carried out, with a progressively higher proportion of operations performed on complex conditions (P<0.001), at an ever younger age (P<0.001), and with a declining perioperative mortality (P<0.001). For the period 1990-1994, 4.2 operations for congenital heart disease/1000 live births were required. Factors which may increase or decrease this rate in future are discussed, along with costs of surgery. Surgery for congenital heart disease has become progressively more aggressive and safer since this method of treatment for these malformations was initiated, but this has occurred at a significant financial cost.

Therapeutic efficacy of multiple intravenous infusions of anti-tumor necrosis factor alpha monoclonal antibody combined with low-dose weekly methotrexate in rheumatoid arthritis

OBJECTIVE

To evaluate the efficacy, pharmacokinetics, immunogenicity, and safety of multiple infusions of a chimeric monoclonal anti-tumor necrosis factor alpha antibody (cA2) (infliximab; Remicade, Centocor, Malvern, PA) given alone or in combination with low-dose methotrexate (MTX) in rheumatoid arthritis (RA) patients.

METHODS

In a 26-week, double-blind, placebo-controlled, multicenter trial, 101 patients with active RA exhibiting an incomplete response or flare of disease activity while receiving low-dose MTX were randomized to 1 of 7 groups of 14-15 patients each. The patients received either intravenous cA2 at 1, 3, or 10 mg/kg, with or without MTX 7.5 mg/week, or intravenous placebo plus MTX 7.5 mg/week at weeks 0, 2, 6, 10, and 14 and were followed up through week 26.

RESULTS

Approximately 60% of patients receiving cA2 at 3 or 10 mg/kg with or without MTX achieved the 20% Paulus criteria for response to treatment, for a median duration of 10.4 to >18.1 weeks (P < 0.001 versus placebo). Patients receiving cA2 at 1 mg/kg without MTX became unresponsive to repeated infusions of cA2 (median duration 2.6 weeks; P=0.126 versus placebo). However, coadministration of cA2 at 1 mg/kg with MTX appeared to be synergistic, prolonging the duration of the 20% response in >60% of patients to a median of 16.5 weeks (P < 0.001 versus placebo; P=0.006 versus no MTX) and the 50% response to 12.2 weeks (P < 0.001 versus placebo; P=0.002 versus no MTX). Patients receiving placebo infusions plus suboptimal low-dose MTX continued to have active disease, with a Paulus response lasting a median of 0 weeks. A 70-90% reduction in the swollen joint count, tender joint count, and C-reactive protein level was maintained for the entire 26 weeks in patients receiving 10 mg/kg of cA2 with MTX. In general, treatment was well tolerated and stable blood levels of cA2 were achieved in all groups, except for the group receiving 1 mg/kg of cA2 alone, at which dosage antibodies to cA2 were observed in approximately 50% of the patients.

CONCLUSION

Multiple infusions of cA2 were effective and well tolerated, with the best results occurring at 3 and 10 mg/kg either alone or in combination with MTX in approximately 60% of patients with active RA despite therapy with low-dose MTX. When cA2 at 1 mg/kg was given with low-dose MTX, synergy was observed. The results of the trial provide a strategy for further evaluation of the efficacy and safety of longer-term treatment with cA2.

Anomalous coronary artery with tetralogy of Fallot and aortopulmonary window

Anomalous origin of the left main coronary artery from the pulmonary artery is rarely associated with other conditions. We report the case of an infant born with tetralogy of Fallot and aortopulmonary window who at the time of surgical repair was found to have an anomalous left main coronary artery originating from the right pulmonary artery.

Changes in leucocyte counts and soluble intercellular adhesion molecule-1 and E-selectin during cardiopulmonary bypass in children

A consequence of cardiopulmonary bypass (CPB) in young children is postoperative capillary leak and associated pulmonary dysfunction. Neutrophils sequester in the lungs and may contribute to functional endothelial damage. The endothelial adhesion molecules, E-selectin and intercellular adhesion molecule-1 (ICAM-1), mediate sequential steps in adhesion by binding to leucocyte ligands. Circulating forms of these proteins have been identified. We studied changes in the plasma concentrations of soluble E-selectin and soluble ICAM-1 using fixed phase immunoassays, and associated leucocyte counts in 10 paediatric patients undergoing CPB. Concentrations of soluble L-selectin and soluble ICAM-1 consistently fell during CPB from preoperative levels of 89 +/- 17 ng/ml (mean +/- 2SEM) and 218 + 61 ng/ml, respectively, to 39 +/- 7 ng/ml and 84 +/- 24 ng/ml, respectively at the beginning of maximum hypothermia. The haemodilution that occurred during CPB largely explained this fall, but not the more marked decrease in white cell counts that also occurred over this period (6.7 +/- 1.1 to 1.7 +/- 0.5 x 10(9)/l) which may reflect increased leucocyte sequestration. By 24 h postoperatively, levels of both soluble adhesion molecules approached preoperative concentrations, as did lymphocyte counts. In marked contrast, neutrophil counts rose appreciably towards the end of CPB, and continued to rise to a maximum of 10.9 +/- 3.1 x 10(9)/l during the immediate postoperative period and remained at these elevated levels 24 h later. Major consistent changes in circulating leucocyte numbers which occur early in cardiopulmonary bypass may reflect changes in adhesion to the endothelium and consequent sequestration. Alterations in the levels of soluble adhesion proteins may influence these processes.

Therapeutic efficacy of multiple intravenous infusions of anti-tumor necrosis factor alpha monoclonal antibody combined with low-dose weekly methotrexate in rheumatoid arthritis

OBJECTIVE

To evaluate the efficacy, pharmacokinetics, immunogenicity, and safety of multiple infusions of a chimeric monoclonal anti-tumor necrosis factor alpha antibody (cA2) (infliximab; Remicade, Centocor, Malvern, PA) given alone or in combination with low-dose methotrexate (MTX) in rheumatoid arthritis (RA) patients.

METHODS

In a 26-week, double-blind, placebo-controlled, multicenter trial, 101 patients with active RA exhibiting an incomplete response or flare of disease activity while receiving low-dose MTX were randomized to 1 of 7 groups of 14-15 patients each. The patients received either intravenous cA2 at 1, 3, or 10 mg/kg, with or without MTX 7.5 mg/week, or intravenous placebo plus MTX 7.5 mg/week at weeks 0, 2, 6, 10, and 14 and were followed up through week 26.

RESULTS

Approximately 60% of patients receiving cA2 at 3 or 10 mg/kg with or without MTX achieved the 20% Paulus criteria for response to treatment, for a median duration of 10.4 to >18.1 weeks (P < 0.001 versus placebo). Patients receiving cA2 at 1 mg/kg without MTX became unresponsive to repeated infusions of cA2 (median duration 2.6 weeks; P=0.126 versus placebo). However, coadministration of cA2 at 1 mg/kg with MTX appeared to be synergistic, prolonging the duration of the 20% response in >60% of patients to a median of 16.5 weeks (P < 0.001 versus placebo; P=0.006 versus no MTX) and the 50% response to 12.2 weeks (P < 0.001 versus placebo; P=0.002 versus no MTX). Patients receiving placebo infusions plus suboptimal low-dose MTX continued to have active disease, with a Paulus response lasting a median of 0 weeks. A 70-90% reduction in the swollen joint count, tender joint count, and C-reactive protein level was maintained for the entire 26 weeks in patients receiving 10 mg/kg of cA2 with MTX. In general, treatment was well tolerated and stable blood levels of cA2 were achieved in all groups, except for the group receiving 1 mg/kg of cA2 alone, at which dosage antibodies to cA2 were observed in approximately 50% of the patients.

CONCLUSION

Multiple infusions of cA2 were effective and well tolerated, with the best results occurring at 3 and 10 mg/kg either alone or in combination with MTX in approximately 60% of patients with active RA despite therapy with low-dose MTX. When cA2 at 1 mg/kg was given with low-dose MTX, synergy was observed. The results of the trial provide a strategy for further evaluation of the efficacy and safety of longer-term treatment with cA2.

Expression of Bcl-2 in human epithelial tumor (HeLa) cells enhances clonogenic survival following exposure to 5-fluoro-2'-deoxyuridine or staurosporine, but not following exposure to etoposide or doxorubicin

A reduced capacity for apoptosis induction is considered to play a significant role both in the development of malignancy and in tumor cell resistance to chemotherapeutic drugs. The Bcl-2 oncoprotein inhibits apoptosis induced by antitumor agents at a point downstream of drug-target interactions. Stable expression of Bcl-2 in the human epithelial tumor (HeLa) cell line results in inhibition of apoptosis following exposure to the topoisomerase II poison, etoposide. However, Bcl-2 is unable to enhance clonogenic survival as a result of alternate pathways to reproductive death induced by the drug.

PURPOSE

The purpose of this study was to further investigate the role of Bcl-2 in human epithelial tumor cell drug resistance using 5-fluoro-2'-deoxyuridine, staurosporine, and doxorubicin, in addition to etoposide.

METHODS

The ability of Bcl-2 to enhance clonogenic cell survival was studied by colony-forming assays, while delay of cell death induction was assessed by trypan blue viability measurements. The proportion of apoptotic cells was measured by morphological criteria, as well as detection of apoptotic DNA fragmentation using the terminal deoxynucleotidyl transferase assay.

RESULTS

Despite profound inhibition to loss of plasma membrane integrity for all agents tested, Bcl-2 was only able to significantly increase clonogenic survival following exposure to 5-fluoro-2'-deoxyuridine and staurosporine, but not following exposure to etoposide or doxorubicin. Furthermore, the time-course of apoptosis induction following exposure of HeLa cells to equitoxic concentrations of staurosporine and etoposide was profoundly different.

CONCLUSIONS

These results indicate that Bcl-2 enhances clonogenic survival of human epithelial tumor cells in an agent-specific fashion, which may be determined by the initial cytotoxic lesion induced by a particular drug.

Primary arterial switch operation for transposition of the great arteries with intact ventricular septum in infants older than 21 days

OBJECTIVES

The aim of this study was to assess the surgical outcome of the primary arterial switch operation (ASO) in infants 3 weeks to 2 months old.

BACKGROUND

The surgical management of transposition of the great arteries and intact ventricular septum (TGA/IVS) beyond 2 to 3 weeks of age is controversial. Concern that regression of the left ventricular (LV) myocardial mass will render the left ventricle incapable of coping with the acutely increased work of systemic perfusion has been considered a contraindication to a primary ASO.

METHODS

We used retrospective analysis of 37 patients 3 weeks to 2 months old and 156 patients <3 weeks old who underwent primary ASO with TGA/IVS to determine the surgical outcomes.

RESULTS

Between January 1990 and December 1996, primary ASO was performed in 37 patients 21 to 61 days old (late ASO group) and 156 patients <21 days old (early ASO group) with TGA/IVS. One (2.7%, 95% confidence interval [CI] 0.07% to 14.2%) of 37 patients and 13 (8.3%, 95% CI 4.5% to 13.8%) of 156 patients died. One late death occurred in each group. Mechanical LV support was required in 1 (2.7%, 95% CI 0.07% to 14.2%) of 37 late ASO and 6 (3.8%, 95% CI 1.4% to 8.2%) of 156 early ASO group patients postoperatively. Neither death nor the need for mechanical LV support in the late ASO group patients could be attributed to LV failure. In the late ASO group, age, LV geometry, LV mass index, LV posterior wall thickness index, LV volume index, LV mass/volume ratio, patent arterial duct or pattern of coronary anatomy did not predict death, duration of postoperative ventilation or inotropic support or time in intensive care. Moreover, there was no difference in duration of ventilation, duration of inotropic support or the time spent in intensive care in comparison to a random sample of 37 neonates from the early ASO group.

CONCLUSIONS

Primary ASO may be appropriate treatment for infants with TGA/IVS < or = 2 months old, regardless of preoperative echocardiographic variables. The upper age limit for which primary ASO is indicated in TGA/IVS is not yet defined.

Modified ultrafiltration improves left ventricular systolic function in infants after cardiopulmonary bypass

OBJECTIVE

Our objective was to test the hypothesis that use of modified ultrafiltration after cardiopulmonary bypass improves intrinsic left ventricular systolic function in children.

METHODS

Twenty-one infants undergoing cardiopulmonary bypass were instrumented with ultrasonic dimension transducers, to measure the anteroposterior minor axis diameter, and a left ventricular micromanometer. Patients were randomized to modified ultrafiltration (n = 11, age 226 +/- 355 days, weight 6.7 +/- 3.1 kg) or control (n = 10, age 300 +/- 240 days, weight 7.0 +/- 2.5 kg) (all differences p > 0.05 between groups). Left ventricular systolic function was assessed by means of the slope of the preload-recruitable stroke work index. Myocardial cross-sectional area was measured by echocardiography. Data were acquired immediately after separation from bypass, at steady state, and during transient vena caval occlusion. Data acquisition was repeated after 13 +/- 5 minutes of modified ultrafiltration or after 12 +/- 5 minutes without modified ultrafiltration in the control group. Inotropic drug support was the same at both study points.

RESULTS

In the modified ultrafiltration group, the filtrate volume was 363 +/- 262 ml. The hematocrit value increased from 26.0% +/- 2.7% to 36.7% +/- 9.5% (p = 0.018), myocardial cross-sectional area decreased from 3.72 +/- 0.35 cm2 to 3.63 +/- 0.36 cm2 (p = 0.04), end-diastolic length increased from 25.6 +/- 9.0 mm to 28.8 +/- 9.9 mm (p = 0.01), and end-diastolic pressure fell from 5.6 +/- 0.8 mm Hg to 4.2 +/- 0.8 mm Hg (p = 0.005), suggesting an improved diastolic compliance. In the control group, the hematocrit value, myocardial cross-sectional area, end-diastolic length, and pressure did not change (all p > 0.05). Mean ejection pressure increased in the ultrafiltration group (p = 0.001) but did not change in the control group (p = 0.22). The slope of the preload-recruitable stroke work index increased after ultrafiltration from 52.3 +/- 52.0 to 74.2 +/- 66.0 (10[3] erg/cm3) (p = 0.02) but did not change in the control group (p = 0.07). One patient from each group died in the postoperative period. Patients in the ultrafiltration group received less inotropic drug support in the first 24 hours after the operation (156.62 +/- 92.31 microg/kg in 24 hours) than patients in the control group (865.33 +/- 1772.26 microg/kg in 24 hours, p = 0.03).

CONCLUSIONS

Use of modified ultrafiltration after cardiopulmonary bypass improves intrinsic left ventricular systolic function, improves diastolic compliance, increases blood pressure, and decreases inotropic drug use in the early postoperative period.

Measurement of cerebral blood flow during cardiopulmonary bypass with near-infrared spectroscopy

OBJECTIVE

A novel noninvasive method for repeatedly measuring cerebral blood flow during cardiopulmonary bypass by near-infrared spectroscopy is described. The reproducibility of the method is investigated and a comparison is made with an established technique.

METHODS AND RESULTS

The method is derived from the Fick principle and uses indocyanine green dye, injected into the bypass circuit, as an intravascular tracer. Cerebral blood flow was measured in nine children undergoing cardiopulmonary bypass on a total of 49 occasions. Results from this study suggest that an integrating period of 4 seconds provided a consistent measurement of global cerebral blood flow. The values obtained ranged from 3.2 to 32.4 (median 15.9) ml.100 gm-1.min-1. In an additional 10 children in whom repeated measurements were made, the coefficient of variation was 11% +/- 7% (mean +/- standard deviation). In a further study, the method was compared with microsphere injection in five piglets undergoing cardiopulmonary bypass. The comparison within each animal with the linear least squares method gave values for R2 in the range 0.91 to 0.99. The gradients of the fits ranged from 0.5 to 1.8 (median 1.0). The mean difference between the two techniques was 5.7 ml.100 gm-1.min-1 or 7%. The coefficient of variation for the piglets was 14% +/- 9% (mean +/- standard deviation).

CONCLUSIONS

Indocyanine green and near-infrared spectroscopy allow frequent and repeated measurements of cerebral blood flow during cardiopulmonary bypass. The measurements are reproducible and accurately reflect changes in cerebral blood flow. It may be widely applicable both in research and clinical practice.

Carotid artery pseudoaneurysm as a complication of ECMO

Any pulsatile neck mass after extracorporeal membrane oxygenation (ECMO) must be viewed as a pseudoaneurysm of the carotid artery until proven otherwise. Prompt diagnosis is necessary utilizing ultrasound. Angiography may not be necessary. Carotid artery pseudoaneurysm requires urgent surgical intervention to prevent catastrophic hemorrhage. The utilization of cardiopulmonary bypass may facilitate safe repair.

The human granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor exists as a preformed receptor complex that can be activated by GM-CSF, interleukin-3, or interleukin-5

The granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor is expressed on normal and malignant hematopoietic cells as well as on cells from other organs in which it transduces a variety of functions. Despite the widespread expression and pleiotropic nature of the GM-CSF receptor, little is known about its assembly and activation mechanism. Using a combination of biochemical and functional approaches, we have found that the human GM-CSF receptor exists as an inducible complex, analogous to the interleukin-3 (IL-3) receptor, and also as a preformed complex, unlike the IL-3 receptor or indeed other members of the cytokine receptor superfamily. We found that monoclonal antibodies to the GM-CSF receptor alpha chain (GMR alpha) and to the common beta chain of the GM-CSF, IL-3, and IL-5 receptors (beta(c)) immunoprecipitated both GMR alpha and beta(c) from the surface of primary myeloid cells, myeloid cell lines, and transfected cells in the absence of GM-CSF. Further association of the two chains could be induced by the addition of GM-CSF. The preformed complex required only the extracellular regions of GMR alpha and beta(c), as shown by the ability of soluble beta(c) to associate with membrane-anchored GMR alpha or soluble GMR alpha. Kinetic experiments on eosinophils and monocytes with radiolabeled GM-CSF, IL-3, and IL-5 showed association characteristics unique to GM-CSF. Significantly, receptor phosphorylation experiments showed that not only GM-CSF but also IL-3 and IL-5 stimulated the phosphorylation of GMR alpha-associated beta(c). These results indicate a pattern of assembly of the heterodimeric GM-CSF receptor that is unique among receptors of the cytokine receptor superfamily. These results also suggest that the preformed GM-CSF receptor complex mediates the instantaneous binding of GM-CSF and is a target of phosphorylation by IL-3 and IL-5, raising the possibility that some of the biologic activities of IL-3 and IL-5 are mediated through the GM-CSF receptor complex.

The relation between pump flow rate and pulsatility on cerebral hemodynamics during pediatric cardiopulmonary bypass

OBJECTIVES

Neurologic impairment, at least partly ischemic in origin, has been reported in up to 25% of infants undergoing cardiopulmonary bypass, with or without circulatory arrest. Controversy continues about the effect of pump flow, pulsatile or nonpulsatile, on the brain and in particular on cerebral blood flow. This study examines the relationship between pump flow rate and cerebral hemodynamics during pulsatile and nonpulsatile cardiopulmonary bypass.

METHOD

Near-infrared spectroscopy was used to determine cerebral blood flow and cerebral blood volume (measured as concentration change) in a randomized crossover study. Pulsatile and nonpulsatile flow were used for six 5-minute intervals at each of three different pump flow rates (0.6, 1.2, and 2.4 L x m2 x min(-1)) in 40 patients, median age 2 months (range 2 weeks to 20 years 5 months). The relations between pulsatile flow, pump flow rate, cerebral blood flow, hemoglobin concentration change (cerebral blood volume), mean arterial pressure, arterial carbon dioxide tension, and hematocrit value were prospectively examined by means of multivariate analysis.

RESULTS

Cerebral blood flow decreased 36% per L x m(-2) x min(-1) decrease in pump flow rate and was associated with changes in mean arterial pressure but did not differ according to pulsatility. Change in hemoglobin concentration was unrelated to changes in pulsatility of pump flow.

CONCLUSION

Cerebral blood flow is related to pump flow rate. Pulsatile flow delivered with a Stöckert pump does not increase cerebral blood flow or alter hemoglobin concentration during cardiopulmonary bypass in children.

Anaemia of chronic disease in rheumatoid arthritis: in vivo effects of tumour necrosis factor alpha blockade

Anaemia of chronic disease (ACD) is a common feature of active rheumatoid arthritis (RA). Inflammatory cytokines, particularly tumour necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1) and interleukin-6 (IL-6), are thought to contribute to the pathogenesis of ACD, possibly by inhibiting erythropoietin (EPO) production. In this study, we examined the in vivo effects of TNF-alpha blockade with a chimeric monoclonal antibody, cA2, on erythropoiesis in RA patients with ACD. Administration of cA2 led to a dose-dependent increase in haemoglobin levels compared to placebo and these changes were accompanied by a reduction in both EPO and IL-6 levels. The data support the notion that TNF-alpha is important in the causation of ACD, but suggest a mechanism independent of EPO suppression. Instead, TNF-alpha may act directly on bone marrow red cell precursors.

Atrioventricular septal defect and tetralogy of Fallot: a 15-year experience

AIM

Atrioventricular septal defect and tetralogy of Fallot is a relatively uncommon lesion in which there is a risk of right ventricular dysfunction related to inlet and outlet valve problems. For this reason, conservative management involving an initial palliative procedure is often chosen. The aim of this report is to retrospectively review our experience with this lesion.

PATIENT POPULATION

35 patients with atrioventricular septal defect and tetralogy of Fallot have been surgically managed at this institution between January 1980 and June 1995. Twenty-one (60%) of these patients underwent 28 initial palliative shunt procedures. Fourteen (40%) patients underwent primary definitive repair. The criteria for choosing one management strategy over another was based on a number of factors, including age at presentation, anatomy of the lesion, and severity of symptoms. Of the 21 patients who underwent an initial shunt procedure, 15 have undergone definitive operation. Of the 6 patients who did not undergo definitive operation, three died (two directly related to complications of the shunt procedure), two are awaiting operation, and one was lost to follow-up.

RESULTS

The primary indication for operation in all patients was cyanosis. Freedom from reoperation at 5 years after definitive operation was 65.1% for all patients; most reoperations were related to left atrioventricular valve regurgitation or residual leaks across the ventricular septal defect patch. The operative mortality at definitive operation was 10.3% (70% CL 4.5-20%) for all patients. The actuarial estimate of survival 7 years following definitive repair was 77.3% (70% CL 68.7-85.9%) for all patients. The actuarial estimate of survival at 7 years was 84.4% (70% CL 73.8-95%) in the patients undergoing primary repair and 65% (70% CL 52.4-77.6%) in patients initially palliated if the mortality of the palliative shunt procedure is included (P = 0.35).

CONCLUSION

Patients with atrioventricular septal defect and tetralogy of Fallot can be successfully managed with a variety of surgical strategies. Primary repair may be a reasonable option in carefully selected patients, as this eliminates the morbidity and mortality of an initial shunt procedure and the subsequent interval between initial palliation and definitive repair.

Suppression of fever and the acute-phase response in a patient with juvenile chronic arthritis treated with monoclonal antibody to tumour necrosis factor-alpha (cA2)

Juvenile chronic arthritis (JCA) is the commonest chronic rheumatic disorder of childhood. Although conventional therapy of JCA continues to improve, many patients experience long-term ill health as a result of their disease or treatment. In adult rheumatoid arthritis (RA), similar concerns have led to the development of therapies designed to interfere in key disease processes. One such therapy is cA2, a chimeric neutralizing monoclonal antibody to the inflammatory cytokine, tumour necrosis factor-alpha (TNF-alpha). The administration of cA2 in adult RA has led to impressive short-term suppression of disease, with a good safety profile. Here, we report the first use of cA2 in childhood arthritis, choosing a patient with severe systemic-onset JCA, resistant to conventional therapies. The patient received two i.v. infusions of cA2, each at a dose of 10 mg/kg, separated by 1 week. The treatment was well tolerated and induced rapid control of fever, anorexia and serositis, together with downregulation of interleukin (IL)-6, soluble TNF receptors (sTNFR) and IL-1ra, and the acute-phase proteins C-reactive protein (CRP) and serum amyloid A (SAA). In contrast, we saw no significant improvement in joint pain or tenderness. Our findings suggest that TNF-alpha is a mediator of fever and other systemic aspects of disease in systemic JCA. TNF-alpha blockade as a treatment modality in JCA deserves further study.

The relation between arterial oxygen tension and cerebral blood flow during cardiopulmonary bypass

OBJECTIVES

Neurological impairment occurs in up to 25% of infants undergoing cardiopulmonary bypass with or without circulatory arrest. Potential causes include alterations in cerebral blood flow, hypoxia and embolisation. During cardiopulmonary bypass, arterial oxygen tension is maintained at levels which under normal conditions cause cerebral vasoconstriction; this is a potential mechanism for ischaemia. The aim of this study was to explore the relation between arterial oxygen tension and cerebral blood flow during cardiopulmonary bypass.

METHODS

Near infrared spectroscopy was used to explore the relation between arterial oxygen tension and cerebral blood flow in 14 patients (median age 8 months; range 1 month to 10 years 11 months). The relations between arterial oxygen tension, arterial carbon dioxide tension, temperature, haematocrit, pump flow rate, mean arterial pressure and cerebral blood flow, were examined using multivariate analysis.

RESULTS

There was no relation between cerebral blood flow and arterial oxygen tension, but a highly significant relation was observed between cerebral blood flow and pump flow rate, with cerebral blood flow decreasing 4.2-fold per L.m-2.min-1 decrease of pump flow rate.

CONCLUSION

There was no relation between arterial oxygen tension and cerebral blood flow during cardiopulmonary bypass, but low pump flow rate may lead to reduced cerebral blood flow.

Heart transplantation for Barth syndrome

Barth syndrome is an X-linked recessive disorder comprising dilated cardiomyopathy, muscular hypotonia, and cyclical neutropenia. Affected children usually die during infancy as a consequence of septicemia, cardiac failure, or both. We report a patient with Barth syndrome who underwent successful heart transplantation.

Stöckert roller pump generated pulsatile flow: cerebral metabolic changes in adult cardiopulmonary bypass

There is evidence that during cardiopulmonary bypass (CPB), pulsatile pump flow improves cerebral metabolism. This was a study to explore the effect of pulsatile versus nonpulsatile perfusion on cerebral lactate, pyruvate, glucose and beta-hydroxybutyrate using a Stöckert roller pump. We found no significant differences between the arterial-venous (A-V) differences of lactate, glucose and beta-hydroxybutyrate (p > 0.05). When the upward trend of A-V pyruvate was accounted for, there was again no difference (p = 0.2). Arterial lactate:pyruvate ratios were not significantly different between pulsatile and nonpulsatile pump flow (p > 0.05). Venous lactate:pyruvate ratios were significantly higher during pulsatile bypass, but when the downward trend was accounted for, the differences between pulsatile and nonpulsatile values were no longer significant (p = 0.4). Therefore, the metabolic changes were not significant. There was no significant difference in systemic vascular resistance (SVR) during pulsatile and nonpulsatile flow (p = 0.4). Pulsatile flow delivered by the Stöckert roller pump appears to have no metabolic or SVR advantages in adults undergoing CPB.

Outcomes after delayed sternal closure in pediatric heart operations: a 10-year experience

BACKGROUND

Open heart operations in young children may lead to myocardial swelling and increased lung water. Decreased intrathoracic space may then make sternal closure difficult. Delayed sternal closure may be beneficial in this setting. Potential risks of delayed sternal closure are sepsis and sternal instability.

METHODS

To assess these risks, we reviewed retrospectively 150 consecutive children who underwent delayed sternal closure after repair of complex congenital cardiac defects.

RESULTS

Diagnoses included transposition of the great arteries (66), total anomalous pulmonary venous drainage (11), and complete atrioventricular septal defects (10). Age at operation was 229 +/- 51 days (mean +/- standard error of mean). Sixteen patients required extracorporeal membrane oxygenation. Survival was 88% (133 patients). The sternum was left open for 3.86 +/- 0.29 days. Fifteen patients had minor wound infections requiring antibiotics. No patient required reexploration for mediastinitis and no patient had an unstable sternum.

CONCLUSIONS

Delayed sternal closure with sternal stenting and silicone membrane skin closure is a safe procedure in infants and children with compromised cardiac output after repair of congenital cardiac defects.

Prospective, randomized, double-blind study of high-dose aprotinin in pediatric cardiac operations

BACKGROUND

Perioperative aprotinin decreases postoperative blood loss in adults undergoing cardiac operations, but its role is less clear in children. Therefore, a trial of aprotinin in pediatric cardiac operations was conducted to study the efficacy of its use in children.

METHODS

Forty-two patients were randomly assigned to receive either high-dose aprotinin or placebo. Aprotinin efficacy was assessed using time from protamine administration to skin closure, postoperative blood loss and hemoglobin loss, and postoperative transfusion requirements. Measures of fibrinolysis (fibrin degradation product titers) and platelet preservation (beta-thromboglobulin levels) were also assessed.

RESULTS

There were no statistically significant differences between groups in any of the blood loss or transfusion parameters. Fibrin degradation product levels, measured 4 hours postoperatively, had increased significantly for control patients, but remained unchanged for the aprotinin group (p < 0.02). beta-Thromboglobulin levels increased more rapidly during cardiopulmonary bypass in the control group (p = 0.03).

CONCLUSIONS

Aprotinin appears to provide no clinical benefit in routine pediatric cardiac operations. A reduction in fibrinolysis, with perhaps an early preservation of platelet structure, is seen in the aprotinin group.

Cardiopulmonary bypass tubes and prime solutions stimulate neutrophil adhesion molecules

OBJECTIVE

To evaluate effects of the material of the cardiopulmonary bypass (CPB) tubes (polyvinyl chloride, PVC) and prime solutions on expression of neutrophil adhesion molecule CD11b and L-selectin.

METHODS

We carried out a series of experiments using donor blood from 30 healthy adult human volunteers. In all experiments, neutrophil cell surface expressions of CD11b and L-selectin were assayed immediately and serially up to 2 hours, using immune-fluorescence techniques and flow cytometry. Study 1: Effects of PVC were compared with glass and polystyrene (n = 5). Study 2: Blood was mixed with Plasma-lyte (Pl) (prime solution), Hartman solutions, albumin or not altered (control), n = 5. Study 3: The effects of changing pH of the Pl (control, neutralised and acidic solution, n = 5) were examined. Study 4: Haemodilution (undiluted, 1:1, 1:2, and 1:3, vol/vol, prime to blood, n = 5) was carried out using Pl and the subsequent changes in expressions of the adhesion molecules were analysed. Study 5: The combined effect of PVC and Pl was assessed (n = 5). Study 6: We evaluated the effect of increasing plasma water by adding sterile water to whole blood and compared it with control (n = 5).

RESULTS

Study 1: PVC, similar to glass, caused more up-regulation of CD11b and down-regulation of L-selectin than polystyrene (238 and 162% vs. 68 increase of CD11b, P < 0.001; 89 and 95% vs. 16% decrease of L-selectin, P < 0.001). Study 2: Pl and Hartman solutions caused more up-regulation of CD11b and down-regulation of L-selectin compared to albumin and control (166 and 188% vs. 26 and 44% increase of CD11b, P < 0.01; 19 and 26% vs. 10 and 6% decrease of L-selectin, P < 0.01, respectively). Study 3: Haemodilution had no effect on these molecules. Study 4: The mean of the difference between the acidic and neutral solution was 208% increase of CD11b and 30% decrease of L-selectin, P < 0.05. Study 5: The combined effect of mixing blood with Pl and exposure to PVC caused marked up-regulation of CD11b (336% increase, P < 0.01) and down-regulation of L-selectin (78% decrease, P < 0.05). Study 6: Water for injection caused marked up-regulation of CD1 1b and down-regulation of L-selectin.

CONCLUSIONS

Mixing blood with acidic prime solution and/or exposing it to PVC tubes causes up-regulation of neutrophil adhesion molecule CD11b and down-regulation of L-selectin. Neutralisation of the prime solution reduces the extent of neutrophil activation, whereas haemodilution has no effect. Increasing plasma water is stimulating to the neutrophil. Modulation of prime solutions and the material of CPB tubes may reduce neutrophil activation which may reduce patient morbidity.

Heart-lung transplantation for patients under 10 with cystic fibrosis

The outcome of patients with cystic fibrosis aged under 10 years referred for heart-lung transplantation assessment (n = 58) was determined and compared with older children (n = 109). Similar proportions were placed on to the active waiting list (64% v 71%) and received transplants (35% v 31%). Three year post-transplantation survival figures were also similar (41% v 46%), as were the figures for overall survival for those placed on to the active list (27% v 29%). Paediatricians should not be deterred from referring younger patients for transplantation.

Mixed total pulmonary venous drainage: still a surgical challenge

OBJECTIVE

The aim of this report is to review the surgical experience of a single institution with a relatively large series of patients with mixed total pulmonary venous drainage.

PATIENT POPULATION

Between January 1, 1971, and December 31, 1994, 232 patients with total pulmonary venous drainage underwent surgical correction. Twenty of these patients (8.6%) had mixed type total pulmonary venous drainage. Ages at operation ranged from 1 day to 46 months, with a median of 2.3 months.

RESULTS

Both cardiac catheterization and echocardiography were performed before operation in 12 patients. Four patients underwent only cardiac catheterization, and another four patients underwent only echocardiography. The sensitivity and specificity for catheterization were 94% and 99%, respectively; they were 31% and 100%, respectively, for echocardiography. Severe pulmonary venous obstruction was present in three patients, all of whom underwent emergency operation. Three patients (15%), all of whom had preoperative pulmonary venous obstruction, died after operation. There were two late deaths, one of pulmonary vein stenosis and the other of probable pulmonary hypertension. The actuarial survival at 10 years was 73% for all patients; patients who survived the initial operation had a 10-year survival of 87%.

CONCLUSION

The diagnosis of mixed total pulmonary venous drainage can be difficult to establish by echocardiography or at the time of operation. For patients in stable condition, cardiac catheterization may be considered if fewer than three pulmonary veins are identified by echocardiography. Pulmonary venous obstruction is relatively infrequent in this group of patients but when present impacts patient survival significantly. The long-term results with this lesion are excellent.

Is a high-risk biventricular repair always preferable to conversion to a single ventricle repair?

OBJECTIVES

The aim of this report is to examine the short-and intermediate-term outcome of a complex biventricular repair compared with a single ventricle repair in patients with two functional ventricles.

PATIENT POPULATION

Since 1986, 34 patients with atrioventricular concordance or discordance, ventriculoarterial discordance, ventricular septal defect, and pulmonary stenosis or atresia have undergone biventricular repair (group I). Another group of 16 patients (group II) with the same diagnoses have undergone a single ventricle repair consisting of a total cavopulmonary connection because of either a straddling atrioventricular valve (11 patients) or an uncommitted ventricular septal defect (5 patients).

RESULTS

The mean length of follow-up was 3.9 years in group I and 3.0 years in group II. Freedom from reoperation at 7 years was 45.5% in group I and 100% in group II (p = 0.014). The actuarial estimate of survival at 7 years was 68.0% in group I and 93.8% in group II (p = 0.048).

CONCLUSION

Short- and intermediate-term morbidity and mortality were greater in patients undergoing a biventricular repair than in a similar group of patients undergoing total cavopulmonary connection. It is unknown whether the long-term results of a total cavopulmonary connection in patients with two ventricles are as good as those obtained with a biventricular approach. However, there may be situations in which the short- and intermediate-term risks of a complex biventricular repair may outweigh the long-term disadvantages of a single ventricle approach.

Pediatric tracheal homograft reconstruction: a novel approach to complex tracheal stenoses in children

PURPOSE

Tracheal stenosis can be a life-threatening problem in children. Long-segment tracheal stenosis and recurrent tracheal stenosis are especially problematic. Tracheal homograft reconstruction represents a novel therapeutic modality for these patients.

METHODS

Cadaveric trachea is harvested, fixed in formalin, washed in thimerosal (Methiolate), and stored in acetone. The stenosed tracheal segment is opened to widely patent segments proximally and distally. The anterior cartilage is excised and the posterior trachealis muscle or tracheal wall remains. A temporary silicone rubber intraluminal stent is placed and absorbable sutures secure the homograft. Regular postoperative bronchoscopic treatment clears granulation tissue. The stent is removed endoscopically after epithelialization over the homograft. Twenty-four children with severe tracheal stenosis (age 5 months to 18 years, mean +/- standard error of the mean = 8.18 +/- 1.21 years) underwent tracheal homograft reconstruction. All but one had had previous unsuccessful reconstructive attempts. Ten lesions were congenital, nine were posttraumatic, and five were due to prolonged intubation.

RESULTS

Follow-up ranged from 5 months to 10 years (3.79 +/- 0.70 years). Twenty patients survive (20/24 = 83%), 16 without any airway problems. Four patients are still undergoing treatment. One patient requiring emergency extracorporeal membrane oxygenator support before the operation died 10 days after tracheal homograft reconstruction. Another patient with severe preoperative mediastinal sepsis died 3.5 months after tracheal homograft reconstruction. Two patients with functional airways died late of unrelated problems.

CONCLUSIONS

Tracheal homograft reconstruction demonstrates encouraging short-term to medium-term results for children with severe recurrent tracheal stenosis. Postoperative bronchoscopic and histologic studies provide evidence of epithelialization and support the expectation of good long-term results.

Expanded PTFE membrane to prevent cardiac injury during resternotomy for congenital heart disease

BACKGROUND

Resternotomy for repair of congenital cardiac defects can result in cardiac injury. Closure of the pericardium during the initial operation may prevent this, and several pericardial substitutes have been tried, with variable results, in patients in whom primary pericardial closure is not possible. We conducted a multicenter observational study of the use of the expanded polytetrafluoroethylene membrane (Preclude Pericardial Membrane, formerly called the Gore-Tex Surgical Membrane; W. L. Gore & Associates, Flagstaff, AZ) in patients likely to undergo reoperation for treatment of congenital heart disease.

METHODS

Data were collected retrospectively on all patients in whom the expanded polytetrafluoroethylene membrane was inserted at the initial operation for congenital heart disease at 12 centers in 1984 to 1993.

RESULTS

A total of 1,085 patients (mean age, 55 +/- 2.5 months) received the membrane. During follow-up ranging from 1.3 to 10.5 years, 105 reoperations were performed. Injury during resternotomy occurred in only 1 patient (1% of reoperations). There were no membrane-related deaths or complications in the entire series of 1,085 patients.

CONCLUSIONS

The expanded polytetrafluoroethylene membrane was safe and effective in helping to prevent cardiac injury during resternotomy for treatment of congenital heart disease.

Deactivation of vascular endothelium by monoclonal anti-tumor necrosis factor alpha antibody in rheumatoid arthritis

OBJECTIVE

To assess whether monoclonal antibody to tumor necrosis factor alpha (TNF alpha) reduces endothelial activation in rheumatoid arthritis (RA).

METHODS

Levels of serum E-selectin, intercellular adhesion molecule 1 (ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1), and circulating leukocytes (differential counts) were measured in RA patients before and up to 4 weeks after infusion of either placebo or chimeric anti-TNF alpha antibody cA2 (1 or 10 mg/kg).

RESULTS

Treatment with anti-TNF alpha decreased serum E-selectin and ICAM-1 levels, with the earliest detectable changes observed on days 1-3 after anti-TNF alpha infusion. No effect on VCAM-1 levels was detected. In parallel, there was a rapid and sustained increase in circulating lymphocytes. The extent of the decrease in serum E-selectin and ICAM-1 levels and the increase in lymphocyte counts was significantly higher (P < or = 0.05) in patients in whom a clinical benefit of anti-TNF alpha was observed ( > or = 20% response, by Paulus criteria, at week 4) compared with that in patients who failed to respond to anti-TNF alpha at this time point.

CONCLUSION

We propose that decreased serum levels of adhesion molecules may reflect diminished activation of endothelial cells in the synovial microvasculature, leading to reduced migration of leukocytes into synovial joints, and thus prolonging the therapeutic effect of anti-TNF alpha in RA.

Successful complete tracheal resection in a three-month-old infant

We report an infant with severe long-segment tracheal stenosis in whom the posterior trachea was formed by complete cartilage rings and the anterior trachea was almost totally formed by a solid cartilage plate. The child was successfully treated initially by complete resection of the trachea and primary end-to-end repair and subsequently with tracheal homograft transplantation for secondary stenosis.

Extracorporeal membrane oxygenation as a bridge to definitive tracheal surgery in children

Extracorporeal membrane oxygenation was used as a bridge for three infants with complicated long segment congenital tracheal stenosis to tracheal homograft transplantation with cadaveric tracheal homograft and for one child, with an extensive traumatic tracheal laceration caused by aspiration of a sharp foreign body, to definitive tracheal repair. In all four cases mechanical ventilation was impossible and death almost certain without extracorporeal membrane oxygenation.

Tracheal reconstruction in children using cadaveric homograft trachea

OBJECTIVE

We report the use of cadaveric human tracheal homograft in the treatment of severe long segment congenital tracheal stenosis in children.

METHODS

Five children (aged 5 months-8 years) with severe life-threatening airway obstruction due to long segment congenital tracheal stenosis had failed conventional management. All were ventilator dependent or rapidly deteriorating at the time of surgery, two were on extracorporeal membrane oxygenation, and no alternative therapy was available. The stenosed trachea was removed and the posterior trachealis muscle left in situ when possible. Surgical technique involved the use of cardiopulmonary bypass in four of five cases. Stored cadaveric tracheal homograft tissue was shaped and inserted over a silastic intra-luminal stent which was kept in place for up to 3 months. Regular bronchoscopy was necessary postoperatively to clear granulation tissue, which resolved on removal of the stent.

RESULTS

Four patients are all now without stents, intubation or tracheostomy. Three are without airway problems 16, 14, and 9 months after surgery and one attends for occasional dilatation of a distal tracheal stenosis, but is now at home despite other severe multiple congenital problems. One patient presented with complete disruption of the trachea and mediastinal sepsis and was supported on extracorporeal membrane oxygenation prior to surgery; this patient eventually died of airway failure and sepsis.

CONCLUSIONS

The application of cadaveric human tracheal homograft to congenital tracheal stenosis is novel. Its use in five children who would otherwise have died has provided an extra therapy in an extremely difficult group of patients.

Endoscopic plantar fascia release: an anatomical study

The anatomical relationship of neurovascular structures to the plantar fascia after endoscopic fasciotomy was studied in 13 adult fresh-frozen cadaver feet. Using a single portal technique, an endoscopic system was placed into the plantar compartment through a 1-cm medial incision. Under direct endoscopic visualization, the plantar fascia was released. The feet were then dissected and the anatomic relationship of the neurovascular structures to the area of release was studied. The average amount of plantar fascia released was 81%. The average distance of the release to the lateral plantar nerve, and the nerve to the abductor digiti minimi was 10.5 and 12.3 mm, respectively. The flexor digitorum brevis muscle was partially transected in 46% of the cases, and the average amount of muscle transected was 0.8 mm. The endoscopic approach to the release of the plantar fascia provides adequate release and does not appear to pose any danger to underlying neurovascular structures.

Anti-cytokine therapy in rheumatoid arthritis

The past few years have seen an explosion of knowledge concerning the role of cytokines and their naturally occurring inhibitors in the promotion and modulation of inflammatory disease. In RA, this knowledge has been translated into the clinic, with ongoing evaluation of specific cytokine inhibitors, including those targeting tumour necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) and interleukin-6 (IL-6). In this review, we outline the scientific data supporting anti-cytokine therapies in RA and describe the results of published and unpublished clinical trials with biological agents. At least for anti-TNF therapy, short-term clinical efficacy and good tolerability have been confirmed in randomized, placebo controlled trials. The results of IL-1 blockade in vivo also appear encouraging, although detailed descriptions of trail outcomes are awaited. Problems associated with long-term administration of biological agents are discussed, including the development of antiglobulin responses to injected monoclonal antibodies and poor pharmacokinetics of low-molecular-weight inhibitors. Ways of facilitating the long-term use of current biological agents and alternative means for inhibiting cytokine function in future studies in RA are presented.

Effect of heparin anticoagulation on neutrophil adhesion molecules and release of IL8: C3 is not essential

OBJECTIVE

To examine the role of heparin in modulating neutrophil activation and release of cytokine.

BACKGROUND

Up-regulation of CD11b, down-regulation of L-selectin on neutrophil cell surface and release of IL8 occur in response to extracorporeal circulation (ECC) and were proposed to cause leakage of the capillaries in patients.

DESIGN

In a series of experiments, we examined the effect of heparin (4 U/ml) comparing it with ethylenediamine tetra-acetate (EDTA, 1.5 mg/ml) and citrate mixture (100 microliters/ml), heparin dose-response, IL8 (human recombinant IL8) dose-response and protamine (80 micrograms/ml) neutralisation of heparin (4 U/ml) using donor blood (total of 38). The role of complement component type 3 (C3) was tested. Neutrophils from a patient with complete C3 deficiency were stimulated by using heparin and cobra venom factor (10 micrograms/ml) and compared with controls (n = 5). CD11b and L-selectin expressions were assayed immediately and serially up to 120 min using immune fluorescence and flow cytometry. Serum concentrations of IL8 were determined by using enzyme-linked immunosorbent assay.

RESULTS

The medians of up-regulation of CD11b were 540.2 (range 235.2-653.3) for heparin vs. 186.5 (55.7-207.1) for EDTA and 192.5 (69.2-263.8) for citrate mixture, P < 0.01. The medians of down-regulation of L-selectin were 79 (32-192) for heparin vs. 18.4 (0-188) for EDTA and 36.2 (7.4-135) for citrate mixture, P < 0.05. Up-regulation of CD11b, down-regulation of L-s and release of IL8 were inversely related to heparin concentration (r = 0.87, P < 0.05). Serum concentration of IL8 had a direct relationship to the changes in CD11b and L-selectin expression (r = 0.92). Heparin-protamine complex was less stimulant to expression of CD11b and L-selectin than heparin or protamine (P < 0.05). In blood samples from C3-deficient patients, heparin and cobra venom factor caused up-regulation of CD11b and down-regulation of L-selectin similar to that of controls (P > 0.05).

CONCLUSIONS

Heparin stimulates up-regulation of neutrophil adhesion molecules CD11b, down-regulation of L-selectin and release of IL8. These effects are inversely related to heparin concentration and are independent of C3 activation. IL8 has a direct relationship to activation of neutrophil adhesion molecules. Increasing heparin dosage reduces neutrophil activation and may reduce the morbidity of patients.

Heart transplantation for dilated cardiomyopathy

Between 1988 and 1994, 23 patients underwent heart transplantation for dilated cardiomyopathy. The age of the 13 boys and 10 girls was from 8 months to 16 years (mean 7.1 years). Selection criteria included failure to thrive despite maximal antifailure treatment and/or intravenous inotrope dependence. The aetiology of cardiomyopathy was idiopathic (n = 13), congenital (n = 3), anthracycline induced (n = 4), Barth's syndrome (n = 1), and maternal systemic lupus erythematosus (n = 2). The waiting period of heart transplantation ranged from one day to 147 days (mean 22 days). Maintenance immunosuppression included cyclosporin, azathioprine, and prednisolone. Follow up after transplantation was from one month to 62 months (median 27 months) with a mean actuarial survival of 95% at one year and 87% at three years. Four patients developed coronary artery disease, one of whom died as a consequence 15 months after heart transplantation. Heart transplantation has emerged as an acceptable therapeutic option, at least in the short term, for patients with dilated cardiomyopathy.

TNF alpha is an effective therapeutic target for rheumatoid arthritis

Rheumatoid arthritis is the most common of a number of diseases in which inflammation and tissue destruction is driven by an autoimmune process. Current therapy is inadequate, and this has prompted major research efforts, both in academia and industry, to understand more about the pathogenesis, and hence provide the rationale for new therapeutic strategies. Here we review our studies of cytokine expression and regulation in rheumatoid joints, which has culminated in demonstrating that TNF alpha blockade, using a chimeric (human IgG1/K, mouse Fv) anti-TNF alpha antibody, cA2, markedly ameliorates arthritis. This defines a therapeutic target for rheumatoid arthritis.

Vascular and contractile function and tissue metabolites after prolonged hypothermic ischaemia and reperfusion: comparison of single- versus multi-dose infusions with two cardioplegic solutions in blood-perfused neonatal pig hearts

The effects of single- and multi-dose cardioplegia on post-ischaemic vascular function and contractile activity were compared in 69 blood-perfused neonatal pig hearts, as were the protective properties of two different cardioplegic solutions. Hearts (n = 6 or 9 per group) from neonatal (3-5 days old) pigs were excised, arrested with a 2 min infusion (at 15 degrees C) of St Thomas' Hospital cardioplegic solution number 1 (STH1) or number 2 (STH2), and then maintained in a state of hypothermic (15 degrees C) ischaemia for 6 or 8 h. Hearts in the multi-dose groups received cardioplegia every hour (2 min at 15 degrees C). At the end of ischaemia all hearts were reperfused (60 +/- 2 mmHg perfusion pressure) for 40 min with blood from a support pig. Systolic and diastolic functions were assessed with an intraventricular balloon, and endothelial and smooth muscle functions by measuring the response to infusions of defined concentrations of acetylcholine (8, 16 and 32 micrograms/min) and glyceryl trinitrate (40, 80 and 160 micrograms/min). Hearts (n = 9) not subjected to ischaemia were perfused for the same duration to act as aerobic controls. At the end of the perfusion period, hearts were frozen and taken for metabolite analysis. After 8 h ischaemia, the recovery of left ventricular developed pressure was greatest in the multi-dose STH1 and single-dose STH2 groups (113 +/- 6 and 117 +/- 6 mmHg, respectively, v 128 +/- 9 mmHg in aerobic controls, at an end-diastolic pressure of between 3 and 9 mmHg; P = N.S.) and the poorest in the single-dose STH1 group (92 +/- 5 mmHg; P < 0.05 v controls). The recovery of diastolic function was greatest in the multi-dose STH2 group and again poorest in the single-dose STH1 group (left ventricular end-diastolic pressure 1 +/- 2 and 30 +/- 10 mmHg, at a ventricular volume of 3.0 ml, v -1 +/- 1 mmHg in aerobic controls). Vascular responses to acetylcholine and glyceryl trinitrate and the myocardial high-energy phosphates content were better preserved in multi-dose groups and with STH2. Inter-group differences were less when the duration of ischaemia was reduced to 6 h. In conclusion, the neonatal pig heart was best preserved with multi-dose cardioplegia and STH2 was more efficacious than STH1. However, not all indices were optimally protected by multi-dose STH2. Thus, the best protection of systolic function was obtained with multidose STH1 and this was followed by single-dose STH2. Diastolic function was best preserved with multi-dose STH2 as were vascular function and high-energy phosphates.

Beneficial effects of tumour necrosis factor-alpha (TNF-alpha) blockade in rheumatoid arthritis (RA)

The biological properties of TNF-alpha make it a candidate therapeutic target in RA. Our studies have demonstrated that TNF-alpha and its receptors are up-regulated and co-expressed in the synovium and cartilage-pannus junction of RA joints. Neutralizing TNF-alpha antibodies reduce the production of the many pro-inflammatory cytokines, including IL-1 and granulocyte-macrophage colony-stimulating factor (GM-CSF), produced by mononuclear cells from RA in culture. When injected into DBA/1 mice with collagen-induced arthritis and TNF-alpha transgenic mice with arthritis, anti-TNF MoAbs decrease inflammatory damage of joints. Clinical trials employing cA2, a chimaeric anti-TNF-alpha MoAb, in open-label and randomized placebo-controlled studies have demonstrated a dose-dependent efficacy with impressive improvement in disease activity and acute-phase responses lasting several weeks. We conclude that TNF-alpha is a critical mediator of inflammation in RA, and is an important therapeutic target in this disease.

Heart transplantation in an infant with rhabdomyoma

Rhabdomyoma is the most common primary cardiac tumor in infants and children and is often associated with tuberous sclerosis. Surgical resection may be indicated and, if so, is usually curative. We describe a rhabdomyoma in an infant who presented with severe myocardial ischemia necessitating orthotopic heart transplantation.

Repair of anomalous pulmonary venous connection to the superior vena cava

Complex forms of anomalous pulmonary venous connection to the superior vena cava (SVC) can be difficult to correct surgically. Since 1987, 11 patients have undergone repair of anomalous pulmonary venous connection to the SVC by diversion of the pulmonary venous drainage to the left atrium using a baffle with division of the SVC and reimplantation on the right atrial appendage to restore normal systemic venous drainage. Total anomalous pulmonary venous connection was present in 3 patients and partial anomalous pulmonary venous connection, in 8. All patients are alive and asymptomatic at a mean follow-up of 2.3 +/- 1.4 years. Postoperative echo-cardiograms (8 patients) revealed pulmonary venous obstruction requiring reoperation in 1 patient. No patient has clinical evidence of SVC obstruction, and all are in sinus rhythm. This is a safe and effective technique for repair of complex forms of anomalous pulmonary venous connection to the SVC, and the incidence of postoperative venous obstruction and rhythm disturbances is low.

Incidence of neurological complications of surgery for congenital heart disease

A total of 523 cardiac surgical discharge summaries were searched for recorded evidence of adverse neurological events occurring between operation and time of discharge. Neurological events were recorded in 31 and included one or more of seizure disorder (n = 16), pyramidal signs (n = 11), extrapyramidal signs (n = 8), coma (n = 6), and neuro-ophthalmic deficits (n = 6). There were significantly more adverse neurological events after repairs for arch anomalies (16.6% of cases). There was also an association with the length of cardiopulmonary bypass and a period of low perfusion pressure either intraoperatively or postoperatively. Of the 19 out of 23 survivors in whom long term outcome data were available, four were normal and six had persisting neurological problems directly related to the perioperative period. In a further nine of the 19 survivors, established preoperative neurodevelopmental abnormality probably contributed to their present neurological status, in addition to perioperative events. In view of the way these data were collected, this study must represent the minimum incidence of neurological events in children undergoing cardiac surgery.

Monoclonal anti-TNF alpha antibody as a probe of pathogenesis and therapy of rheumatoid disease

Rheumatoid arthritis is a common cause of chronic disability for which current therapies are of limited value in controlling the disease process and outcome. Our initial approach to understanding the pathogenesis of RA and defining a novel therapeutic target was to investigate the role of cytokines by blocking their action with antibodies on cultured synovial-derived mononuclear cells in vitro. These investigations suggested that neutralization of TNF alpha with antibodies significantly inhibited the generation of other pro-inflammatory cytokines also over-produced, such as, IL-1, GM-CSF, IL-6 and IL-8. The implication that blockade of a single cytokine, TNF alpha might have far-reaching effects on multiple cytokines and thereby exert significant anti-inflammatory and protective effects on cartilage and bone of joints, was tested in arthritic DBA/1 mice immunized with collagen II. Impressive amelioration of joint swelling and joint erosions in this model encouraged clinical trials with a monoclonal anti-TNF alpha antibody. The cA2 chimeric anti-TNF alpha high-affinity antibody was initially tested in an open-label study at a dose of 20 mg/kg on 20 patients, with substantial and universal benefit. Subsequently, a randomized placebo-controlled double-blind trial was performed on 73 patients comparing a single intravenous injection of placebo (0.1% human serum albumin) with two doses of cA2. Using a composite disease activity index, at 4 weeks post infusion, 8% of patients receiving placebo improved compared with 44% receiving 1 mg/kg cA/2 and 79% receiving 10 mg/kg. Between 2 to 4 repeated cycles of cA2 were administered to 7 patients and all patients showed improvement of a similar magnitude with each cycle. These data support our proposition that TNF alpha is implicated in the pathogenesis of RA, and is thus a key therapeutic target. Monoclonal anti-TNF alpha antibodies control disease flares and are candidate agents for longer-term control of RA, although repeated therapy with cA2 is associated with anti-idiotypic responses in 50% of patients and a trend toward shortening of the duration of response. In the DBA/1 arthritic mice, synergy of action of anti-TNF and anti-CD4 is observed together with suppression of an anti-globulin response, indicating one way in which benefit might be augmented in the future.

TNF alpha blockade in rheumatoid arthritis: rationale, clinical outcomes and mechanisms of action

Tumor necrosis factor alpha (TNF alpha) is a cytokine with many biological functions of relevance to inflammatory disease. Although only one of several inflammatory mediators produced in abundance in rheumatoid arthritis (RA), experimental data suggest that it is in a dominant position within a cytokine hierarchy and is therefore a prime target for directed immunotherapy in this disease. We have targeted TNF alpha in vivo using a chimerised monoclonal anti-TNF alpha antibody and have now demonstrated beneficial responses to treatment in three different clinical trials. The results confirm that TNF alpha is of central importance in the inflammatory process in RA and define a new treatment strategy in this disease.

Supravalvar mitral stenosis: risk factors for recurrence or death after resection

OBJECTIVE

To assess the medium term outcome in infants and children after surgical resection of supravalvar mitral stenosis with special reference to risk factors for mortality or recurrence of supravalvar mitral stenosis. No detailed follow up has been previously reported in this uncommon condition.

DESIGN

Prospective cross sectional clinical and echocardiographic follow up.

SETTING

Paediatric cardiothoracic unit.

PATIENTS AND METHODS

23 consecutive children (14 male, nine female, mean age 3 years 2 months at surgery) who underwent resection of supravalvar mitral stenosis between 1978 and 1993.

RESULTS

Follow up was for a mean of 58 months (range 0.5-167) after resection of supravalvar mitral stenosis. Four patients developed recurrent supravalvar mitral stenosis: this has not been reported previously. This was recognised 14-108 months after resection and confirmed at repeat operation. Three of these patients had successful reoperations but one died. Five other patients died. On multivariate analysis the only variable associated with survival free of recurrent supravalvar mitral stenosis was older age (18 months or more) at time of surgery (hazard ratio 0.17, 95% confidence interval (CI) 0.03 to 0.95, P < 0.05). Five year actuarial survival free of recurrent obstruction when supravalvar mitral stenosis was resected at age less than 18 months was only 39% (95% CI 9 to 69%) compared with 73% (95% CI 24 to 93%) in older patients.

CONCLUSION

Supravalvar mitral stenosis is part of a spectrum of obstructive lesions affecting the left heart. Recurrent supravalvar mitral stenosis can develop after surgical resection. The prognosis in those who require resection within the first 18 months of life is poor: mortality is high, as is the risk of recurrent supravalvar mitral stenosis in survivors, probably because of continuing turbulent flow across a small left ventricular inflow tract.

Results of heart-lung transplantation in children with cystic fibrosis

Children with cystic fibrosis represent the largest group referred for, and undergoing, heart-lung transplantation at our institute. Between June 1988 and July 1993, 76 patients were accepted for transplantation, of whom 25 were transplanted, while a further 36 died waiting. Those transplanted ranged from 5-18 years of age and included 13 males and 12 females. Organs were used from donors matched by ABO blood group, size and cytomegalovirus (CMV) status. Post-transplant maintenance immunosuppression comprised cyclosporin A, azathioprine and prednisolone. Anti-thymocyte globulin and high dose methylprednisolone were given peri-operatively and for acute rejection episodes. Actuarial survival was 67% at 1 year, 61% at 2 years and 54% at 3 years. Obliterative bronchiolitis (OB) has occurred in 13 patients (52%) and was the major cause of mortality and morbidity. In three patients, OB was associated with the development of tracheal anastomotic stenosis. Other complications included diabetes mellitus (n = 9), pancreatitis (n = 1) and hypertension (n = 8). Despite these problems, those surviving the first year post-transplant showed a mean FEV1 of 71% (compared to 29% pre-transplant) and enjoyed an overall improved quality of life.

Neutrophil activation in paediatric extracorporeal circuits: effect of circulation and temperature variation

OBJECTIVE

Upregulation of neutrophil adhesion molecules (CD11b and L-selectin) and release of a modulating cytokine (IL8) have been reported in vivo and in vitro in adult cardiopulmonary bypass. The aim of this study was to determine whether paediatric bypass preparations have similar influences and whether neutrophil-endothelium interactions are required for IL8 release.

METHODS

In vitro paediatric cardiopulmonary bypass circuits (n = 15) were constructed (identical to those used clinically), as well as static loops (n = 15) using donor blood. The effects of circulation and temperature (17 degrees C, 25 degrees C, 37 degrees C) on the initiation of acute inflammation were examined. Cellular expressions of neutrophil adhesion molecules CD11b and L-selectin were assayed by immunofluorescence technique, and serum IL8, IL6, TNF-alpha, leucocyte elastase, and terminal complement complex were measured by ELISA.

RESULTS

In all experiments, an immediate increase in CD11b expression occurred [median values, in relative fluorescence units: 64.9 (range 45.3-212.9) at rest; 365.2 (205-835.4) at 10 min; P < 0.001], along with a decrease in L-selectin expression [153.5 (115.5-220.7) at rest; 42 (12-134) at 10 min; P < 0.01]. Serum concentrations of the following increased gradually and were higher in circulation than in static loops: IL8 [1500 (500-2500) pg.ml-1 in circuit v 600 (180-1500) pg.ml-1 in loop, P < 0.001]; TNF-alpha P < 0.05]; and terminal complement complex [25.9 (6.8-120) v 4.7 (0-21.6) AU.ml-1, P < 0.01]. Cooling decreased and rewarming increased upregulation of CD11b and downregulation of L-selectin and release of IL8. IL6 was undetectable.

CONCLUSIONS

In the absence of endothelium, in vitro paediatric cardiopulmonary bypass causes profound acute inflammatory changes in donor blood with release of IL8. These changes were greater than in adult cardiopulmonary bypass. Temperature variation and circulation modulate the responses.

Randomised double-blind comparison of chimeric monoclonal antibody to tumour necrosis factor alpha (cA2) versus placebo in rheumatoid arthritis

Tumour necrosis factor alpha (TNF alpha) is a critical inflammatory mediator in rheumatoid arthritis, and may therefore be a useful target for specific immunotherapy. In support of this hypothesis, we previously observed beneficial responses in patients with active rheumatoid arthritis after open-label administration of a chimeric monoclonal antibody to TNF alpha (cA2). We now report the results of a four-centre, randomised double-blind trial of a single infusion of 1 or 10 mg/kg cA2 compared with placebo in 73 patients with active rheumatoid arthritis. The primary endpoint of the study was the achievement at week 4 of a Paulus 20% response, an amalgam of six clinical, observational, and laboratory variables. Intention-to-treat analysis of data from individual patients showed only 2 of 24 placebo recipients responding at this time, compared with 11 of 25 patients treated with low-dose cA2 (p = 0.0083) and 19 of 24 patients treated with high-dose cA2 (p < 0.0001). Over half of the high-dose cA2 patients responded by the more stringent 50% Paulus criteria at this time (p = 0.0005). The magnitude of these responses was impressive, with maximum mean improvements in individual disease-activity assessments, such as tender or swollen-joint counts and in serum C-reactive protein, exceeding 60% for patients on high-dose treatment. There were two severe adverse events. 1 patient on 1 mg/kg cA2 developed pneumonia ("possibly" treatment-related) and 1 on 10 mg/kg had a fracture ("probably not" treatment-related). The results provide the first good evidence that specific cytokine blockade can be effective in human inflammatory disease and define a new direction for the treatment of rheumatoid arthritis.

Repeated therapy with monoclonal antibody to tumour necrosis factor alpha (cA2) in patients with rheumatoid arthritis

Our in-vitro, animal, and early clinical data suggest that tumour necrosis factor alpha (TNF alpha) is an important target for specific biological therapy in rheumatoid arthritis. We report the results of repeated treatment with a chimeric monoclonal antibody to TNF alpha (cA2) in patients having disease flares. 7 patients originally enrolled in an open-label trial completed two to four cycles, each of which was followed by a good clinical response, with median improvements in the swollen-joint count and C-reactive protein exceeding 80%. cA2 may be useful therapy in the control of acute disease flares in rheumatoid arthritis and treatment programmes including cA2 may be effective in the long-term management of this disease.