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N D Bridges

Publications and source records attributed to N D Bridges.

At least 37 records · Page 2Linked to original sources
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

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

Hemodynamic data and survival in children with pulmonary hypertension.

OBJECTIVES: Using data from a multi-institutional data base, we sought to determine whether hemodynamic data predict duration of survival in children with primary or secondary pulmonary hypertension. BACKGROUND: Lung transplantation is a therapeutic option for children with pulmonary hypertension. Appropriate timing of lung transplantation requires reliable methods of predicting duration of survival in potential candidates. METHODS: A regional data base was used to obtain cardiac catheterization data on 50 children with mean pulmonary artery pressure (mPAP) > 25 mm Hg and indexed pulmonary resistance (Rp) > 4.5 Wood units. Data on survival were obtained from the participating centers. RESULTS: There were 15 patients without congenital heart disease (group 1) and 35 patients with congenital heart disease (group 2) for analysis. Actuarial survival at 1, 2 and 5 years was 86%, 69% and 69% in group 1 and 88% and 77% in group 2, respectively (p = NS). Hemodynamic variables that predicted survival on univariate analysis were mean right atrial pressure (mRAP) (p < 0.0001), mPAP (p = 0.034), Rp (p < 0.0001) and pulmonary flow (p = 0.003), as well as a variable that we generated-mRAP x Rp (p < 0.0001). On multivariate stepwise logistic regression analysis, mRAP x Rp was independently related to survival. A model using mRAP x Rp allows for the estimation of probability of death at 1 and 2 years after catheterization. CONCLUSIONS: Hemodynamic variables can predict survival in children with pulmonary hypertension in the presence or absence of congenital heart defects. This information can be used to determine the optimal timing of listing for lung transplantation.

Blood Pressure↗
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↗
PubMed1996

Outcome of children with pulmonary hypertension referred for lung or heart and lung transplantation.

We reviewed our institutional experience with 24 children with pulmonary hypertension, who were referred for lung or heart and lung transplantation. Diagnosis, age, and previously published predictive survival scores calculated at the time of referral were analyzed as predictors of pretransplant death. Among the 24 children, 7 did not meet criteria for listing and 17 were listed for transplantation. Of those listed, eight died waiting, two await transplantation, and seven were transplanted and are alive and well 7-20 months after transplantation. Poor functional status (New York Heart Association class 3 or 4) at the time of referral was significantly associated with death before transplant (P=0.05) in univariate analysis. Analysis of the predictive scores was possible in 21 of 24 patients; lower predictive scores were significantly associated with death before transplantation and shorter duration of survival without transplantation in univariate analysis. Multivariate analysis (Cox regression) confirmed that lower scores were significantly associated with poor survival. We conclude that children with pulmonary hypertension are often referred for transplantation too late in the course of their disease. Early complete hemodynamic evaluation before the onset of severe symptoms, followed by serial evaluations of disease progression and consultation with a transplant center, should result in earlier, more appropriate time of listing and improved survival. A systematic study of pretransplant mortality among all children listed for lung transplantation would provide a basis for clinical decision making and policies affecting organ allocation.

Adolescent↗
PubMed1996

Echocardiographic characteristics of biopsy-proven cellular rejection in infant heart transplant recipients.

BACKGROUND: Echocardiography has been used as a primary means to detect cellular rejection in infant heart transplant recipients. There is, however, limited information correlating echocardiography and biopsy-proven rejection in this age group. METHODS: Between September 1989 and July 1994, 32 consecutive heart transplantations were done in infants younger than 20 months old, who were followed up for 2 to 58 months (mean 28 months) with concurrent endomyocardial biopsy and M-mode echocardiography with digitization. M-mode data from all 16 episodes of rejection (International Society for Heart and Lung Transplantation grade 3A or greater) that occurred in 12 grafts were compared with data from the same grafts with histologic resolution of rejection 2 weeks after treatment and with data from biopsy-proven nonrejecting control grafts matched for sex, time after transplantation, donor weight, and donor age. RESULTS: Left ventricular mass index increased in rejection (86 +/- 9 gm/m2) versus resolution (64 +/- 6 gm/m2) and versus that in nonrejecting control grafts (59 +/- 8 gm/m2). Left ventricular shortening fraction increased in rejection (40% +/- 2%) versus resolution (38% +/- 10%). Septal thickening fraction decreased in rejection (33% +/- 9%) versus nonrejection (68% +/- 16%). These changes became significant only in grafts transplanted more than 1 month before study. Substantial overlap of measurements prevented identification of threshold values. Intraobserver and interobserver variabilities for standard M-mode data were 7% to 8% and 12% to 22%, respectively, whereas those for digitized parameters were markedly elevated at 37% to 71% and 51% to 81%, respectively. CONCLUSIONS: We found (1) left ventricular mass index increases in cellular rejection but may be unreliable less than 1 month after transplantation and (2) significant interobserver and intraobserver variability may limit the applicability of digitized echo parameters to the detection of rejection in infant heart transplant recipients.

Acute Disease↗
PubMed1996

Lung transplantation in infancy and early childhood.

BACKGROUND: Experience with lung transplantation in infants and young children is limited. Small size, vulnerability to infection, and limited modalities for rehabilitation and surveillance of the transplanted lung make this group particularly challenging. METHODS: We reviewed the course of all children up to the age of 25 months who underwent lung transplantation at two centers between July 1990 and February 1995. RESULTS: Lung transplantation was performed in 17 patients under the age of 25 months, with concurrent cardiac repair in 14. Prior thoracic surgery had been performed in 12; six patients had mechanical ventilation, and three were supported with extracorporeal membrane oxygenation while waiting for lungs. The mean waiting time was 37 days (range 1 to 197 days). Hospital survival was 12 of 17 (71%); there was one late death. Early deaths were due to hemorrhage (two patients), cytomegalovirus and lymphoproliferative disease (one patients), and viral pneumonitis (two patients). The one late death was due to overwhelming gastroenteritis of unknown origin. One additional patient had graft failure caused by viral pneumonitis and underwent successful retransplantation. Bronchial stenosis occurred at 3 of 33 anastomoses. At a mean follow-up of 22 months, surviving patients were well, without supplemental oxygen, and, although small in stature, had normal linear growth. CONCLUSIONS: Lung transplantation is a reasonable therapy for very young patients with limited life expectancy and no other therapeutic alternative, with outcomes comparable with those achieved in older patients. Early recognition of lung transplant candidates and advances in the prevention, diagnosis, and treatment of viral illness may improve survival in these patients.

Actuarial Analysis↗
PubMed1996

Lung transplantation in children.

Lung transplantation can offer improved quality of life and prolonged survival to children who have end-stage cardiopulmonary disease, even in the presence of characteristics that have been considered poor prognostic indicators. At present, children who have pulmonary hypertension tend to be referred for transplantation late in the course of their disease; as a result, almost half die before organs become available. Cardiac catheterization for accurate disease staging, appropriate timing of evaluation and listing for transplantation, and referral to centers experienced in the treatment of children who have end-stage cardiovascular disease are all essential components of a process that will improve survival in such children. Our experience indicates that there may be important developmental differences in the body's response to lung transplantation; thus, protocols that are suitable for older adolescents and adults may be unsuitable for young children. An integrative approach to investigation of these issues, i.e., one in which careful clinical observation and data acquisition are combined with targeted bench research, is most likely to result in insights that will directly benefit patients.

Child↗
PubMed1995

Rational approach to use of heparin during cardiac catheterization in children.

OBJECTIVES: We sought to determine an anticoagulation protocol for use during cardiac catheterization in children. BACKGROUND: There are few data to indicate which dose of heparin represents adequate anticoagulation or how best to monitor its efficacy. In this study, adequate anticoagulation was defined as the amount of heparin needed to prevent a significant increase in serum fibrinopeptide A, a sensitive marker for thrombin activity. The degree of heparinization was estimated by the activated clotting time. METHODS: Thirty-six children (1 month to 19.5 years old) with congenital heart disease underwent diagnostic cardiac catheterization; 13 of these 36 patients had an additional interventional procedure. Sheaths and catheters were flushed with heparinized saline (1 IU/ml); during the procedure, 33 of the 36 patients received either a 50- or a 100-IU/kg heparin bolus. Paired fibrinopeptide A and activated clotting time samples were obtained throughout each procedure. RESULTS: Increasing the activated clotting time with heparin resulted in a dose-related decrease in fibrinopeptide A levels. A single heparin bolus of either 50 or 100 IU/kg elevated the activated clotting time above baseline level (209 +/- 52 s after 50 IU/kg, 270 +/- 57 s after 100 IU/kg vs. 133 +/- 20 s at baseline [p < 0.0001]) and reduced fibrinopeptide A levels below baseline (7.9 +/- 14 ng/ml after 50 IU/kg, 4.8 +/- 3.7 ng/ml after 100 IU/kg vs. 38 +/- 59 ng/ml at baseline [p < 0.0001]). Heparin flush alone did not increase the activated clotting time above baseline and failed to suppress an increase in fibrinopeptide A levels. There were no differences in activated clotting time and fibrinopeptide A values between patients undergoing diagnostic or interventional procedures. CONCLUSIONS: Administration of a heparin bolus to maintain an activated clotting time > 200 s prevented a significant increase in thrombin activity. Heparin flush alone did not provide adequate anticoagulation. Patients undergoing an interventional procedure did not require more heparin than that needed for a diagnostic procedure.

Adolescent↗
PubMed1995

Orthodeoxia-platypnea due to intracardiac shunting--relief with transcatheter double umbrella closure.

The safety and efficacy of transcatheter clamshell occlusion of patent foramen ovale for relief of severe arterial desaturation and dyspnea in the upright position due to intracardiac shunting were examined in eight patients with excessive risk of surgical patent foramen ovale closure. All patients had successful reduction of intracardiac shunting with an immediate rise in oxygen saturation > or = 95% by implantation of a clamshell device on the atrial septum. Despite two early incidents of device embolization, retrieval and immediate re-implantation, and one patient with nonsustained atrial and ventricular arrhythmias, there were no adverse clinical sequelae. In follow-up evaluation transcatheter clamshell closure of patent foramen ovale has provided persistent relief from shunt-related arterial desaturation and symptomatology in all living patients.

Adult↗
PubMed1995

Lung transplantation in children and young adults with cardiovascular disease.

Single or bilateral lung transplantation was performed in 20 patients with pulmonary hypertension or an inadequate pulmonary vascular bed; all but 1 had congenital heart disease. The average age was 6.3 years (range, 3 months to 23.9 years). All were in New York Heart Association class IV, and 6 were hospitalized and receiving intensive support before transplantation. Hospital survival was 70% (14/20), with three additional deaths at 7, 11, and 27 months. A prior thoracic operation contributed to three of six hospital deaths from hemorrhage. All late deaths were due directly or indirectly to obliterative bronchiolitis. At a mean follow-up of 19 months (range, 2 to 48 months), 10 of 11 survivors are in New York Heart Association class I. Survival after hospital discharge and incidence of obliterative bronchiolitis are similar in a contemporary group of 41 patients of comparable age who underwent lung transplantation for pulmonary disease (p = not significant). Single or bilateral lung transplantation is an acceptable therapy for children with pulmonary hypertension, congenital heart disease, or both. Further investigation in the areas of pretransplantation survival, operative risk factors, and long-term outcome of single-lung recipients and recipients with hemodynamically insignificant intracardiac lesions are needed to develop optimal decision-making strategies for these patients.

Adolescent↗
PubMed1995

Lung transplantation for congenital pulmonary vein stenosis.

BACKGROUND: Congenital pulmonary vein stenosis is a uniformly fatal disease when left untreated. Transcatheter techniques (for example, balloon dilation and stent placement) have proved to be only temporizing measures, and previous surgical attempts at treatment of this entity have provided little improvement and few survivors. METHODS: Over the last 4 years, 6 patients with congenital pulmonary vein stenosis have been treated at our institution, 3 of whom underwent bilateral sequential lung transplantation. RESULTS: The 3 patients who underwent bilateral lung transplantation are alive and well 6 to 24 months after transplantation. The other 3 died of complications of the disease before donor lungs became available. CONCLUSIONS: Making the diagnosis of congenital pulmonary vein stenosis requires a high index of suspicion, and referral for lung transplantation should be made as soon as the diagnosis is reached. Lung transplantation has resulted in good-quality short to medium-term survival for 3 patients with this otherwise untreatable disease.

Constriction, Pathologic↗
PubMed1995

Cardiac catheterization and test occlusion of the interatrial communication after the fenestrated Fontan operation.

OBJECTIVES: Our objective was to determine whether catheterization data obtained after a fenestrated Fontan operation influenced patient management or predicted functional status. BACKGROUND: Cardiac catheterization after a fenestrated Fontan operation is undertaken to identify residual lesions and to observe the patient's response to test occlusion of the baffle fenestration. METHODS: Sixty patients undergoing both a fenestrated Fontan operation before July 1991 and a postoperative catheterization before March 1992 were included in the study. Catheterization data were collected according to a test occlusion protocol; these data were reviewed, and the patient's clinical status at follow-up was ascertained. RESULTS: Test occlusion resulted in a significant increase in systemic venous pressure, arterial oxygen saturation and arteriovenous difference in oxygen content (p < 0.0001). After test occlusion, systemic venous pressure was 40% higher and systemic venous saturation 23% lower among patients with an unfavorable versus a favorable response to test occlusion, although differences between the two groups were subtle or inapparent in the baseline state. Branch pulmonary artery stenosis (identified and balloon dilated in 6 patients) and grade 2 or 3 aortopulmonary collateral vessels (identified and coil embolized in 20) were associated with elevation in systemic venous pressure (p < 0.01). After an average of 2 years of follow-up, there were no deaths, and 50 (83%) of 60 patients were in New York Heart Association functional class I. The only postoperative characteristic significantly associated with being in functional class I at follow-up was a systemic venous pressure < 17 mm Hg. CONCLUSIONS: Cardiac catheterization with test occlusion of the interatrial communication provides useful information after a fenestrated Fontan operation. Conditions associated with elevated systemic venous pressure should be sought and treated, and the response of systemic venous pressure to test occlusion should be considered when deciding whether to close an interatrial communication.

Cardiac Catheterization↗
PubMed1994

Maturational and hemodynamic factors predictive of increased cyanosis after bidirectional cavopulmonary anastomosis.

Bidirectional cavopulmonary anastomosis (BCA) is thought to be beneficial in the palliation of patients with univentricular congenital heart disease considered at high risk for Fontan repair. Experience with patients undergoing BCA suggested that those who were older or larger at the time of surgery tended to be more cyanotic postoperatively than their younger and smaller counterparts. This study was designed to identify correlates of systemic arterial oxygen saturation after BCA. Specifically, it was postulated that maturational changes in blood flow distribution might be associated with decreasing arterial oxygen saturation. Database records of all 110 patients undergoing BCA at our institution from June 1988 until the end of 1991 were reviewed. Postoperative catheterization data were available for 66 patients. Twenty-one patients were excluded because they had potentially reversible causes of cyanosis yielding inestimable degrees of error in hemodynamic calculations. In the remaining 45 patients, univariate and multivariate regression analyses were used to identify correlates of systemic arterial oxygen saturation. Growth and maturation as represented by body surface area exhibited a highly significant inverse correlation with arterial oxygen saturation (p = 0.005), as did pulmonary vascular resistance (p = 0.003). Patients who underwent BCA when > 3.9 years of age or with body surface area > 0.65 m2 were at significantly increased risk for excessive postoperative cyanosis, defined as systemic arterial oxygen saturation < or = 75% (p < 0.005). The interval between surgery and catheterization correlated directly with arterial oxygen saturation (p = 0.002), indicating a tendency toward earlier study of more cyanotic patients. None of the other variables examined correlated significantly with arterial oxygen saturation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Predictors of operative mortality and morbidity after infant heart transplantation.

We retrospectively analyzed the impact of recipient, donor, and operative factors on the operative mortality and morbidity of 36 consecutive infant heart transplantations. Operative survival was excellent at 94%. Among 34 survivors, operative morbidity in 12 patients included acute severe allograft failure with or without prolonged ventilatory support. The cohort was characterized by age less than 4 months (32 of 36), a diagnosis of hypoplastic left heart syndrome (29 of 36), and the use of circulatory arrest (27 of 36); these variables were colinear and could not be used to predict operative mortality or morbidity. None of the remaining recipient, donor, or operative characteristics predicted survival or acute severe allograft failure. A donor-to-recipient weight ratio greater than 2 and a circulatory arrest time greater than 39 minutes predicted the need for prolonged ventilatory support. Despite the need for aggressive or prolonged support after 12 of 36 transplantations, operative survival was high at 94% (34 of 36 procedures, 32 of 34 patients). The use of less restrictive donor criteria combined with aggressive management of acute allograft failure can result in excellent operative survival after infant heart transplantation.

Female↗
PubMed1994

Transcatheter coil embolisation of a pulmonary arteriovenous malformation in a neonate.

Pulmonary arteriovenous malformations (PAVM) are a rare cause of cyanosis in neonates. A large PAVM in a neonate was successfully occluded by transcatheter embolisation. At six months follow up the PAVM was undetectable and no new lesions were found. Transcatheter embolisation should be considered as the primary treatment for a PAVM in a child of any age.

Arteriovenous Malformations↗