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Biomedical subjects

T L Spray

Publications and source records attributed to T L Spray.

At least 73 records · Page 4Linked to original sources
PubMed1998

Sinus node function after a systematically staged Fontan procedure.

BACKGROUND: Sinus node dysfunction has been previously reported to occur in 13% to 16% of patients after the Fontan operation. Although there is concern that an intermediate cavopulmonary connection may increase the risk of sinus node dysfunction, previous studies have not reported on patients routinely staged to a Fontan operation. This study sought to determine the early and late incidences of sinus node dysfunction in patients systematically and uniformly staged to a Fontan operation after a prior hemi-Fontan. METHODS AND RESULTS: To determine the early incidence of sinus node dysfunction, hospital records and perioperative ECGs were reviewed in all 287 patients having had a staged Fontan operation between January 1990 and December 1995. A cross-sectional analysis was performed on 220 of 239 surviving patients (92%) to determine the late incidence of sinus node dysfunction. Sinus node dysfunction was present in 7% of the patients before and in 15% after the hemi-Fontan. Although most patients (81%) regained normal sinus node function between the 2 stages, 23% had sinus node dysfunction in the early postoperative period after the Fontan. Of the 95 patients followed for > 4 years after the Fontan operation, 44% had sinus node dysfunction. However, at a mean follow-up of 3.5 +/- 1.7 years, only 16 patients (6.7%) had received a pacemaker and only 10 (4.1%) had documented atrial flutter. CONCLUSIONS: Perioperative sinus node dysfunction is common after both the hemi-Fontan and the Fontan procedures. Although many patients regain sinus node function between the 2 stages, late sinus node dysfunction is common and more likely to occur in patients with early sinus node dysfunction and those with longer follow-up.

Adolescent↗
PubMed1998

Evaluation of the aortic root by MRI: insights from patients with homozygous familial hypercholesterolemia.

BACKGROUND: In homozygous familial hypercholesterolemia (HFH), the aortic root is prone to develop atherosclerotic plaque at an early age. However, the aortic wall and plaque have not yet been assessed in this condition by MRI. We evaluated the aortic root by use of MRI in 17 HFH patients and 12 normal control subjects in a prospective, blinded, controlled study. METHODS AND RESULTS: Morphological assessment of the aortic root was done with spin-echo and gradient-echo MRI scanning. Comparisons were made with a number of measures of disease severity, including cholesterol-year score, calcium score on electron-beam CT (EBCT), and size of Achilles tendon xanthomas. Atherosclerotic plaque, visible on fat-suppressed images but never on water-suppressed images, was present in 9 HFH patients (53%). Supravalvular aortic stenosis was present in 7 patients with HFH (41%). Maximum supravalvular aortic wall thickness was significantly greater and OD and lumen cross-sectional area (CSA) were smaller in patients than in control subjects (P=0.006, 0.0005, and 0.06, respectively). Maximum wall thickness was associated with a greater calcium score on electron-beam CT (P=0.02). Although the cumulative exposure of the aortic root to cholesterol (the cholesterol-year score) was significantly correlated with the Achilles tendon CSA and vascular calcification, this score did not correlate with the wall thickness or aortic CSA. CONCLUSIONS: This study not only demonstrates the utility of MRI for detecting and characterizing aortic root atherosclerotic plaque and supravalvular aortic stenosis in HFH patients but also suggests that the LDL receptor plays a direct or indirect role in aortic mural development and vascular growth.

Achilles Tendon↗
PubMed1998

Acute changes in preload, afterload, and systolic function after superior cavopulmonary connection.

BACKGROUND: Superior cavopulmonary connection reduces the volume work of the single ventricle. METHODS: To determine the effects of superior cavopulmonary connection on preload, wall stress (or afterload), and systolic ventricular function, we studied 9 patients before and after operation, and at hospital discharge. Using echocardiography, preload was estimated by the ventricular end-diastolic area, and wall stress was calculated at end-systole and peak-systole. Ventricular function was represented by rate-corrected velocity of circumferential fiber shortening and fractional area change divided by rate-corrected ejection time. RESULTS: End-diastolic area and wall stress decreased postoperatively. Ventricular wall thickness increased with a concomitant decrease in cavity area. There was no change in mean blood pressure or heart rate or in rate-corrected velocity of circumferential fiber shortening or fractional area change divided by rate-corrected ejection time. These findings persisted at hospital discharge. CONCLUSIONS: In single ventricles, superior cavopulmonary correction results in an immediate decrease in preload and afterload. The decrease in afterload results primarily from alterations in ventricular geometry. Although no improvement in systolic function was noted, diminished work related to the reduction in loading conditions may have beneficial long-term effects on preserving myocardial performance.

Anastomosis, Surgical↗
PubMed1998

Surgical management of tricuspid atresia and anomalous left brachiocephalic vein.

An anomalous left brachiocephalic vein is an uncommon systemic venous anomaly, which usually has no clinical significance. We describe a case of tricuspid atresia with such an anomalous left brachiocephalic vein. The presence of this unusual venous anomaly had a number of implications in the surgical management of the tricuspid atresia.

Anastomosis, Surgical↗
PubMed1998

Use of aprotinin in pediatric organ transplantation.

BACKGROUND: Pediatric thoracic organ transplantation is associated with an increased risk of perioperative bleeding. Many of these patients are undergoing repeat surgical procedures and in general require cardiopulmonary bypass. METHODS: This article reviews the efficacy and safety of the serine protease inhibitor aprotinin in improving hemostasis in pediatric transplantation. RESULTS: A review of the literature and investigations from Children's Hospital of Philadelphia suggest that aprotinin is beneficial in pediatric lung transplantation: high-risk patients do as well as low-risk patients. Aprotinin also appears to be of benefit in redo heart transplantations, particularly in patients who have had previous sternotomy or previous transplantation. Repeat use of aprotinin appears to be safe and does reduce blood loss in retransplantation patients. Use in the pump prime and a maintenance dose of aprotinin may be the most effective protocol. At this time, however, it is uncertain whether aprotinin is valuable in primary heart transplantation in low-risk patients. CONCLUSIONS: Current practice at Children's Hospital of Philadelphia is to use aprotinin in all lung and heart-lung transplantations and in all redo transplantations: lung, heart-lung, and heart. The use of aprotinin in primary heart transplantations is limited to patients who have had previous sternotomies or thoracotomies.

Aprotinin↗
PubMed1998

Perioperative conduction and rhythm disturbances after the Ross procedure in young patients.

BACKGROUND: The Ross procedure is performed for a variety of left ventricular outflow tract diseases in children. The preoperative hemodynamic burden of pressure or volume overload and associated ventricular hypertrophy can predispose to ventricular arrhythmias. Additional procedures performed with the Ross procedure (eg, Konno) may damage the conduction system. METHODS: Between January 1995 and February 1997, the Ross procedure was performed in 42 patients, 31 (74%) of whom had 71 prior interventions. Concomitant procedures (n = 42 in 23 patients) included 17 annular-enlarging procedures. Screening was performed for perioperative conduction and rhythm abnormalities. RESULTS: There was one postoperative death. Perioperative ventricular tachycardia occurred in 12 patients (29%), with 2 receiving antiarrhythmic medication for ventricular tachycardia at discharge. Transient complete heart block occurred in 3 patients, all of whom had concomitant procedures performed in the subaortic area; all patients were discharged in sinus rhythm and no patient received a permanent pacemaker. CONCLUSIONS: The Ross procedure can be performed successfully in children with complex cardiac disease with low mortality and perioperative morbidity. The incidence of perioperative ventricular tachycardia is high (29%), suggesting the need for vigilant perioperative monitoring and long-term surveillance.

Arrhythmias, Cardiac↗
PubMed1998

Increased pulmonary blood flow produces endothelial cell dysfunction in neonatal swine.

BACKGROUND: The mechanisms by which increased pulmonary blood flow results in pulmonary hypertension have not been determined. METHODS: To determine if increased pulmonary blood flow produces endothelial dysfunction that precedes vascular remodeling and smooth muscle proliferation, neonatal swine (n = 12) (age, 6.1+/-0.5 days) underwent ligation of the left pulmonary artery (LPA) to increase blood flow to the right lung. At 12 weeks of age, endothelium-dependent vasodilatation was assessed by acetylcholine infusion and endothelium-independent vasodilatation by inhaled nitric oxide (NO) in the LPA group and age-matched controls (CON) (n = 11). RESULTS: Mean pulmonary artery pressure was 24.1+/-3.0 mm Hg in the LPA group and 20.8+/-1.9 mm Hg in the CON group (p < 0.1). Pulmonary vascular resistance was 13.2+/-2.2 Wood units in the LPA group and 5.8+/-0.8 Wood units in the CON group (p = 0.001). Acute occlusion of the left pulmonary artery in the CON group increased pulmonary vascular resistance to 6.9+/-3.9 Wood units (p = 0.04). Administration of acetylcholine in the CON group after preconstriction with the thromboxane A2 analogue U46619 resulted in a 30.6%+/-5.4% decrease in pulmonary vascular resistance. In the LPA group, acetylcholine produced paradoxical vasoconstriction and a 15.4%+/-4.1% increase in pulmonary vascular resistance (p < 0.001 versus CON) indicating loss of endothelium-dependent vasodilatation. Nitric oxide decreased pulmonary vascular resistance by 41.9%+/-3.3% in the CON group and 30.8%+/-2.7% in the LPA group (p = 0.04 versus CON), indicating preserved endothelium-independent vasodilatation in both groups. Morphometric analysis was performed in 4 animals from each group. Medial wall thickness as percent of external diameter of small arteries (<100 microm) was the same in both groups (6.4%+/-0.4% in the LPA group versus 6.6% +/-0.4% in the CON animals; p > 0.1). CONCLUSIONS: Increased pulmonary blood flow in immature animals produces endothelial cell dysfunction with loss of endothelium-dependent vasodilatation before the onset of pulmonary vascular remodeling. Subsequent smooth muscle proliferation may be mediated by endothelium-derived factors.

Animals↗
PubMed1998

Outcome after operations for pulmonary atresia with intact ventricular septum.

OBJECTIVE: Pulmonary atresia with intact ventricular septum is an anatomically heterogeneous anomaly with a variety of surgical strategies possible. We sought to compare the outcome of patients with a single ventricle approach to those with a biventricular repair and to compare outcome of patients with coronary abnormalities to those with normal coronary arteries. METHODS: A retrospective review of our surgical database revealed 67 patients with pulmonary atresia with intact ventricular septum operated on between 1981 and 1998. Patients were categorized on the basis of initial surgical strategy: strategy A, aortopulmonary shunt alone (n = 31); strategy B, right ventricular recruitment (n = 32); strategy C, heart transplantation (n = 4). Tricuspid valve size (Z-score) and coronary anatomy were determined. Right ventricular-coronary artery dependency was noted in 8 patients. RESULTS: Overall actuarial survivals at 1, 5, and 8 years were 82%, 76%, and 76%. Mortality was highest in infancy (10 of 16 deaths). Outcome was equivalent for all 3 strategies. There was no difference in tricuspid valve size between survivors and nonsurvivors (mean Z-score -2.0 (2.5) vs -2.0 (1.9), P =.83). There was no difference in survival based on severity of coronary abnormality. Only one third of patients had a successful biventricular repair, and the tricuspid valve was significantly larger in these than in patients who had Fontan operation (mean Z-score -0.53 [1.6], range -3.5 to 1, versus mean Z-score -3.03 [2.7], range -5.5 to 0, P =.002). CONCLUSIONS: Surgical outcome for patients born with pulmonary atresia with intact ventricular septum is satisfactory. The strategies of biventricular repair, single ventricle palliation, and heart transplantation allow for equal outcome among all anatomic subtypes.

Coronary Angiography↗
PubMed1998

Adenovirus infection in the lung results in graft failure after lung transplantation.

OBJECTIVES: Our goal was to examine the relationship between viral pneumonia and outcome in pediatric patients undergoing lung or heart-lung transplantation. METHODS: Prospective surveillance for common respiratory viruses of childhood was performed in all patients undergoing lung or heart-lung transplantation. Specimens were examined for the presence of replicating virus (by culture), viral genome (by polymerase chain reaction), and viral antigen (by immunofluorescence and immunohistochemical staining). The relationship between viral infection and outcome was examined. RESULTS: Sixteen patients underwent 19 transplants during the study period, with follow-up of 1 to 26 months. Virus was identified in the transplanted lung in 29 instances; adenovirus was identified most commonly (8/16 patients) and had the greatest impact on outcome. In 2 patients with early, fulminant infection, adenovirus was also identified in the donor. Adenovirus was significantly associated with respiratory failure leading to death or graft loss and with the histologic diagnosis of obliterative bronchiolitis (P < or = .002 in each case). CONCLUSIONS: Adenovirus infection in the transplanted lung is significantly associated with graft failure, histologic obliterative bronchiolitis, and death. Health care personnel and families must be vigilant in preventing exposure of transplant recipients to this virus. Availability of a rapid and reliable test for adenovirus in donors and recipients would have an impact on management and could improve outcome for pediatric lung recipients.

Adenovirus Infections, Human↗
PubMed1998

Update on lung transplantation in children.

Lung transplantation is an important treatment option in children with acquired and congenital pulmonary disease. Indications for lung transplantation include pulmonary hypertension, bronchopulmonary dysplasia, pulmonary vein stenosis, and cystic fibrosis. The early outcome following lung transplantation has improved considerably. Longterm complications, however, including infections, bronchiolitis obliterans, and complications of immunosuppression remain significant problems. Donor availability, especially for neonates, continues to limit the utilization of lung transplantation.

Child↗
PubMed1997

Comparison of patterns of pulmonary venous blood flow in the functional single ventricle heart after operative aortopulmonary shunt versus superior cavopulmonary shunt.

In this study we investigated the patterns of pulmonary venous flow in children with functional single ventricles to obtain a better understanding of the determinants of transpulmonary blood flow. Sixty-eight patients with functional single ventricles and aortopulmonary shunt (n = 34, group I), or superior cavopulmonary connection (n = 34, group II) underwent transesophageal Doppler echocardiographic assessment of flow in the left upper pulmonary vein before undergoing the next stage of surgery. Twelve patients from group II also underwent simultaneous evaluation of superior vena caval flow. Biphasic forward pulmonary venous flow was noted in 62 patients in sinus rhythm (S wave in systole, D wave in diastole); in 6 patients with junctional rhythm, significant early systolic reversal of flow was present. Both the S- and D-wave velocity-time integrals (VTI) were greater in group I than in group II (S(VTI) 9.9 +/- 4.2 vs 8.0 +/- 2.6, p = 0.02; D(VTI) 8.0 +/- 3.5 vs 4.2 +/- 2.6, p <0.001). In both groups, pulmonary venous flow was predominantly systolic; however, the proportion of flow during ventricular systole was significantly greater in group II than in group I (S(VTI)/D(VTI) group II: 2.4 +/- 1.5; group I 1.4 +/- 0.5, p = 0.001; percent systolic fraction of pulmonary venous flow group II = 67%, group I = 56%, p <0.001). Analysis of superior vena caval flow in group II revealed a single predominant wave with onset at early systole and peak in late systole at a mean of 150 ms after the pulmonary venous S-wave peak. Our data suggest that ventricular systole (i.e., atrial relaxation, atrioventricular valve descent) asserts great influence on transpulmonary blood flow in the functional single ventricle.

Echocardiography, Doppler↗
PubMed1997

Pediatric lung transplantation--are there surgical contraindications?

Lung transplantation has evolved as a successful treatment for end-stage cardiopulmonary disease in children; however, clear guidelines regarding surgical exclusion criteria for pediatric lung transplant candidates have not been well-established. Since December 1994, we have performed 10 bilateral lung transplants and 1 heart-lung transplant in 10 recipients (mean age, 7 years; range, 3 months to 19 years). Indications for transplantation included pulmonary vascular disease (n=6), bronchiolitis obliterans (n=2), bronchopulmonary dysplasia (n=1), graft failure due to viral pneumonitis (n=1), and cystic fibrosis (n=1). Among the 10 patients, 4 were evaluated elsewhere for lung transplantation; of these, 3 were rejected by 1 or more programs because of "high-risk" characteristics. We considered 8 of the 10 patients to have 1 or more "high-risk" characteristics, as follows: previous chest operations other than open lung biopsy (n=6 patients having 1-4 previous operations), ventilator-dependence with tracheostomy and high-dose corticosteroids (n=4), redo lung transplant (n=2), concomitant intracardiac repair (n=6), portal hypertension (n=1), and the use of extracorporeal membrane oxygenation (ECMO) at the time of transplant (n=1). Our standard operative approach was a bilateral thoracosternotomy. Cardiopulmonary bypass was used for explant of the recipient lungs and implant of the donor lungs, and during repair of coexisting congenital heart defects. Aprotinin and fresh whole blood were administered during the procedure to aid in hemostasis. Concomitant procedures were frequently performed and included repair of an intra-atrial baffle leak (prior Mustard procedure), closure of an atrial septal defect, repair of partial anomalous pulmonary venous return, reconstruction of the pulmonary venous confluence, ECMO decannulation, and splenectomy. There were no operative deaths, and no patient required re-exploration for bleeding. One patient had primary graft failure due to adenovirus infection of the donor lungs, and required prolonged mechanical ventilation and eventually ECMO support until retransplantation was performed. The mean hospital stay after transplant was 25+/-13 days (range, 10-56 days). All patients were discharged with a natural airway. Airway complications consisted of one bronchial anastomotic stricture which required dilation, for a complication rate of 5% per anastomoses at risk. One patient required reoperation for stenosis of the superior vena cava. There have been no late deaths, with a mean follow-up of 7+/-4 months (range, 1-13 months). We attribute this 100% operative and short-term survival in these "high-risk" pediatric lung transplant recipients to our operative methods, a multidisciplinary approach to postoperative management, and the enormous physiologic reserve of pediatric patients. Therefore, the standard exclusion criteria used for adult lung transplantation may not be applicable to the pediatric age group. We hope to use these data to expand the use of lung transplantation in pediatric patients.

Actuarial Analysis↗
PubMed1997

Modified ultrafiltration reduces postoperative morbidity after cavopulmonary connection.

BACKGROUND: Modified ultrafiltration reduces the deleterious effects of cardiopulmonary bypass in children. Patients undergoing repair of single-ventricle cardiac anomalies may be particularly sensitive to these adverse effects, and benefit from the use of modified ultrafiltration. METHODS: From January 1995 to June 1996, 120 consecutive cavopulmonary operations were performed at The Children's Hospital of Philadelphia. Procedures included lateral tunnel fenestrated Fontan (n = 50), extracardiac Fontan (n = 5), hemi-Fontan (n = 60), and bidirectional Glenn shunt (n = 5). Modified ultrafiltration was performed after cardiopulmonary bypass in 41 patients, and results were compared by t test with a control group of 79 patients in whom modified ultrafiltration was not used. RESULTS: There was one death for an operative (30-day) mortality of 0.8%. Age, weight, diagnosis, ischemic arrest time, and cardiopulmonary bypass time were similar between the modified ultrafiltration and control groups. Postoperative blood use, chest tube output, the incidence of pleural and pericardial effusions, and hospital stay were all significantly decreased when modified ultrafiltration was used. CONCLUSIONS: By lowering the perioperative morbidity of staged cavopulmonary operations, modified ultrafiltration makes an important contribution to improving outcome after the correction of single-ventricle cardiac anomalies.

Adolescent↗
PubMed1997

Lung transplantation for treatment of infants with surfactant protein B deficiency.

OBJECTIVE: To evaluate lung transplantation for treatment of surfactant protein B (SP-B) deficiency. STUDY DESIGN: We compared surfactant composition and function from pretransplantation and posttransplantation samples of bronchoalveolar lavage fluid, somatic and lung growth, neurodevelopmental progress, pulmonary function, and pulmonary immunohistology in 3 infants with SP-B deficiency who underwent bilateral lung transplantation at 2 months of age and 3 infants who underwent lung transplantation for other reasons. RESULTS: Two years after transplantation, the 2 surviving infants with SP-B deficiency exhibited comparable somatic growth and cognitive development to the comparison infants. All infants had delays in gross motor development that improved with time. Both groups have exhibited normal gas exchange, lung growth, and pulmonary function. The SP-B-deficient infants have also exhibited normal SP-B expression and pulmonary surfactant function after lung transplantation. In two SP-B-deficient infants antibody to SP-B developed. No pathologic consequences of this antibody were identified. CONCLUSIONS: Apart from the development of anti-SP-B antibody, the outcomes for SP-B-deficient infants after lung transplantation are similar to those of infants who undergo lung transplantation for other reasons. Lung transplantation offers a successful interim therapy until gene replacement for this disease is available.

Antibodies↗
PubMed1997

Pediatric lung transplantation at St. Louis Children's Hospital, 1990-1995.

Although accepted therapy in adults, lung transplantation in children is less well established. Reports from the few existing pediatric centers have involved relatively small patient number. Seventy-nine patients underwent 88 lung transplant procedures at St. Louis Children's Hospital between June 1990 and August 1995. Twenty-one transplants (24%) were done in 19 infants and children under the age of 3 yr. Twelve-, 24-, and 48-mo actuarial survival for the primary transplants was 69%, 67%, and 60%, respectively. Survival improved over the course of the program: 12-mo survival for patients transplanted during the first 18 mo was 42% compared with 78% for those transplanted after December 1991. Survival of children transplanted at younger than 3 yr of age was comparable to older children and adults. However, younger children had a lower incidence of acute rejection; none developed bronchiolitis obliterans. Both graft growth and linear growth occurred. Risk factors for early mortality included presence of aortopulmonary collateral vessels and prior thoracic surgery. Risk factors for survival duration included requiring assisted ventilation at the time of transplant, continuous supplemental oxygen requirement, and presence of aortopulmonary collateral vessels. The major late complication was bronchiolitis obliterans, which occurred in 27% of patients and played a role in 64% of late deaths. Investigation of the lower incidence of acute rejection and bronchiolitis obliterans in younger versus older children may reveal important information about the etiology of this disease. The ultimate long-term success of lung transplantation will depend on identification and treatment of the mechanisms responsible. A multicenter data registry would facilitate further clinical studies of pediatric lung transplantation.

Bronchiolitis Obliterans↗