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Biomedical subjects

L L Bailey

Publications and source records attributed to L L Bailey.

144 records · Page 8Linked to original sources
PubMedDate not supplied

Changes in left ventricular mass with rejection after heart transplantation in infants.

Thirty-three infants who underwent successful heart transplantation before 6 months of age were studied to evaluate subacute changes in left ventricular mass (LVM) and its correlation to a history of rejection episodes. LVM and left ventricular wall mass (LVWM) and their percentage of predicted normal values were analyzed by means of M-mode echocardiography. LVM (as a percentage of predicted normal for body surface area) at 1 week, 1 month, and 3 months after transplantation was 103.2% +/- 24.5%, 137.3% +/- 36.0%, and 138.6% +/- 32.0%, respectively. Values for the wall mass were 82.1% +/- 23.0%, 111.3% +/- 35.7%, and 104.6% +/- 30.4%. After 1 and 3 months, both LVM and LVWM were significantly (p less than 0.01) increased from the values in the first week. The patients were subdivided on the basis of a history of rejection. There were six patients without a rejection episode within 1 month (group 1), 17 patients with one rejection episode (group 2), and 10 patients with two or more episodes (group 3). LVM at 1 month was 104.5% +/- 27.7% for group 1, 142.5% +/- 27.7% for group 2 (p less than 0.05), and 148.9% +/- 31.3% for group 3 (p less than 0.05). LVWM at 1 month was 83.4% +/- 24.6%, 114.8% +/- 35.3%, and 122.2% +/- 36.2% (groups 1 through 3, respectively). Thus an increase in posttransplant LVM may signify a rejection episode. Heart transplantation in infancy increases LVM and LVWM (septum and posterior wall); the degree of thickening of septum correlates well with rejection episodes.

Cardiomegaly↗
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Real-time monitoring of the endomyocardial biopsy site with pediatric transesophageal echocardiography.

We studied the feasibility of transesophageal echocardiography to guide endomyocardial biopsies in five heart transplant patients and two baboons with heart transplantations. The patients were 1 month to 1.5 years old with weight range of 2.9 to 9.5 kg. The two juvenile baboons weighed 6.6 and 7 kg. Transesophageal echocardiography was performed uneventfully in all cases with the use of sedation and anesthesia, which were necessary for catheterization. The combination of four-chamber and short-axis views easily identified the exact location of the bioptome within the heart, views that fluoroscopic imaging could not provide. Transesophageal echocardiography proved to be a safe and useful tool for guiding the endomyocardial biopsy procedure. With further refinement endomyocardial biopsy with only transesophageal echocardiography guidance could become the routine method for endomyocardial biopsies in infants, particularly when there are abnormalities of heart situs or position.

Animals↗
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Aggressive peritoneal dialysis for treatment of acute kidney failure after neonatal heart transplantation.

Many infants with hypoplastic left heart syndrome are now treated with heart transplantation. Preoperative or postoperative systemic/renal hypoperfusion occurs frequently, however, resulting in perioperative kidney failure. Of 45 neonates undergoing heart transplantation at our institution, we report on 10 (22%) who required postoperative peritoneal dialysis. Patients' age at transplantation ranged between 1 and 31 (mean, 16.7) days, average weight was 2912 (range, 2140 to 3664) gms. Peritoneal dialysis was started at a mean of 51 hours after transplantation for treatment of anuria (5 patients, 50%), oliguria (3 patients, 30%), fluid overload or hyperkalemia (1 patient each, 10%) and continued for a mean of 101 +/- 90.5 (range, 33 to 270) hours. The value for blood urea nitrogen fell from 46.7 +/- 15.6 mg/dl to 14.3 +/- 10.5 mg/dl, and serum creatinine levels decreased from 2.4 +/- 1.0 mg/dl to 0.6 +/- 0.3 mg/dl throughout peritoneal dialysis. All patients continued to receive cyclosporine during dialysis. Hyperglycemia developed in four patients. Five of 10 patients had ongoing sepsis during dialysis, but only one died while on dialysis (10%). Two patients died late, after peritoneal dialysis was discontinued. Follow-up ranges from 2 months to 5 years. At most recent follow-up, mean creatinine level was 0.5 +/- 0.1 mg/dl. We conclude that aggressive peritoneal dialysis may result in high salvage rates with low morbidity, without the need to discontinue cyclosporine in the setting of neonatal heart transplantation and acute kidney failure.

Acute Kidney Injury↗
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Early recognition of heart transplant rejection by backscatter analysis from serial 2D ECHOs in a heterotopic transplant model.

The acute phase of heart transplant rejection was evaluated with two-dimensional echocardiographic (2D ECHO) image analysis in a modified Mann's cervical heterotopic transplant. Serial 2D ECHO images were obtained daily, and myocardial biopsies were obtained on the day of transplant, on day 3 after transplant, and after total rejection. Brightness of serial 2D myocardial ECHO images significantly increased to day 3 after transplant, indicating increased backscatter during hyperacute rejection. Histologically this was associated with myocardial edema. These results suggest a potential noninvasive means of recognizing acute cardiac rejection. Heart transplant rejection is characterized by myocardial edema during the early stages. Myocardial edema resulting from ischemia increases the backscatter of ultrasound, which is seen as increased brightness on 2D ECHOs. Hence we hypothesized that myocardial edema observed histologically during a hyperacute rejection process can be seen on serial 2D ECHOs of the transplanted heart. Serial 2D ECHOs were obtained in five goats that had undergone a modified Mann's cervical heterotopic transplant. Image parameters were kept constant throughout each experiment. After each experiment, 2D ECHOs of a soft-tissue phantom were also recorded with the same image parameters and were used for normalizing the myocardial brightness estimated from 2D ECHO images. Visually, brightness of 2D ECHO images of all transplanted myocardia increased to day 3 after transplantation; thereafter, the brightness decreased but was still greater than on the day of transplantation. The measured mean (+/- SD) relative integrated brightness increased from 0.60 +/- 0.38 on the day of transplantation to 1.05 +/- 0.43 (p less than 0.005) on day 3 after transplantation and decreased to 0.70 +/- 0.33 (p less than 0.05) on day 7 after transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Role of cardiac replacement in the neonate.

Since January 1978, orthotopic heart transplantation has been investigated in the Surgical Research Laboratories of Loma Linda University. The encouraging results obtained and the release of cyclosporine for use in heart recipients stimulated our interest in heart transplantation in newborns with hypoplastic left heart syndrome. Institutional approval of the investigational protocol for clinical trials of orthotopic cardiac transplantation in newborns was obtained for a first cross-species (baboon to human) heart transplant in a neonate. This report summarizes our experience in this area.

Animals↗
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Orthotopic transplantation for total anomalous pulmonary venous connection associated with complex congenital heart disease.

BACKGROUND: When total anomalous pulmonary venous connection is associated with other complex cardiac malformations, early and late postsurgical morbidity and mortality are excessive. METHODS: In an attempt to modify this outcome, twelve children (4 days to 6.8 years of age) with total anomalous pulmonary venous connection and various congenital cardiac defects were treated with orthotopic heart transplantation. Associated cardiac diagnoses included the following: hypoplastic left heart syndrome (n = 2), unbalanced atrioventricular canal with pulmonary atresia (n = 2), and single ventricle with severe pulmonary stenosis (n = 3) or atresia (n = 5). Two patients had situs inversus, and two had dextrocardia with situs ambiguous. Eight patients had asplenia and one had polysplenia. Palliative pretransplantation procedures in five patients included the following: systemic to pulmonary artery shunt (n = 5), atrioventricular valve annuloplasty (n = 1) and classical Glenn shunt (n = 1). The donor left atrium was anastomosed directly to a common pulmonary venous pool in nine patients; whereas three children required complex reconstruction to baffle the pulmonary venous flow to the donor left atrium. RESULTS: There was one operative death related to an oversized heart and vena caval thrombosis. Follow-up ranged from 16 months to 4.5 years (average 3 years). In two patients (18%) pulmonary venous obstruction developed 3 and 4 months after transplantation. Reoperation to relieve the obstruction was successful in one patient. The second patient underwent three such reoperations and died of sepsis 10 months after orthotopic heart transplantation. CONCLUSION: Orthotopic transplantation is a viable option for children with complex total anomalous pulmonary venous connection that precludes a biventricular repair. Transplantation may improve the dismal prognosis of those children, but it does not eliminate the potential for late pulmonary venous obstruction.

Child↗
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Prospective evaluation of echocardiography for primary rejection surveillance after infant heart transplantation: comparison with endomyocardial biopsy.

Rejection surveillance is critical to successful heart transplantation, and infant recipients have necessitated the use of noninvasive measures. The survival, incidence of rejection, and accuracy of echocardiography in predicting treatable rejection, as detected on right ventricular endomyocardial biopsy, were prospectively studied in infants. The survival rate (82%) and rejection rate (1.4 rejection episodes per 100 patient days) of infants who underwent transplantation during the study were comparable to other studies that used heart biopsy only. Echocardiography was 98% accurate at predicting biopsy results. The sensitivity of echocardiography was 92%, and the specificity was 98%. We conclude that echocardiography can be used successfully for primary rejection surveillance in infants and that right ventricular biopsy is infrequently required.

Biopsy↗
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Serial echocardiographic evaluation of cardiac graft rejection after infant heart transplantation.

The effects of cardiac graft rejection on infant myocardial function as assessed by echocardiography are largely unknown. To quantitate the myocardial response to rejection, serial echocardiographic studies were prospectively performed on 20 infants (less than 1 year of age at transplantation). Two-dimensional guided-M-mode tracings were digitized and quantified with a computer-assisted format. Rejection was diagnosed by clinical criteria, and 85% were graded as mild, that is without cardiac signs or symptoms. Echocardiographic analysis was blinded to rejection status, with studies available 4.2 +/- 2.9 days before rejection, on the day of rejection diagnosis, and 2.9 +/- 1.5 days after rejection treatment. Left ventricular mass increased acutely from 109% of predicted normal to 129% with rejection and decreased to 110% with therapy (p < 0.01). Left ventricular volume also tended to fall with rejection and increase with therapy. The left ventricular volume/mass ratio fell from 0.29 +/- 0.10 to 0.25 +/- 0.13 and increased to 0.37 +/- 0.15 (p < 0.05) with treatment. Systolic function was depressed by rejection as reflected in the posterior wall thickening fraction and velocity of wall thickening. Diastolic dysfunction was reflected in a decreased velocity of posterior wall thinning (-9.7 +/- 3.9 to -7.7 +/- 2.7 and recovery to -10.8 +/- 3.8 (1/second, p < 0.05) and depressed average velocity of cavity enlargement (41.2 +/- 9.6 to 36.4 +/- 8.9 and recovery to 40.7 +/- 8.6 mm/sec, p < 0.05). The utility of these echocardiographic measurements to predict rejection has not been prospectively compared with the endomyocardial biopsy.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Volume↗
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Cardiac transplantation for infants with hypoplastic left-heart syndrome.

OBJECTIVE: To determine whether cardiac transplantation improves the natural history of infants with hypoplastic left-heart syndrome and to examine differences in outcome as a function of the pretransplant period. DESIGN: Retrospective cohort study. Historical, clinical, and laboratory data were collected during the pretransplant period, the in-hospital period, and for up to 6 years following transplantation. Data were analyzed using the product-limit estimate and the log rank test. SETTING: A tertiary, acute care, university teaching hospital. PATIENTS: All 111 infants with hypoplastic left-heart syndrome who entered and completed a protocol leading to transplantation from November 19, 1985, to December 31, 1991. Infants who died while waiting for transplantation were included. INTERVENTION: Orthotopic cardiac allotransplantation. MAIN OUTCOME MEASURES: Pretransplant waiting mortality and its influence on posttransplant survival, operative (in-hospital or within 30 postoperative days in discharged patients) and intermediate-term mortality (5 years), and reoperation rates for cardiac surgery. RESULTS: Transplantation procedures were performed in 84 infants (76%; 95% confidence interval [CI], 66% to 83%) ranging in age from 3 hours to 151 days. Twenty-seven infants registered for transplantation died while awaiting a donor heart. Operative mortality was 13% (CI, 7% to 23%), and 69 patients were late survivors (62% [CI, 52% to 71%] of the study group and 82% [CI, 72% to 89%] of the transplant recipients). Overall 5-year actuarial survival was 61% (CI, 52% to 70%). Transplant recipients had a 5-year survival of 81% (CI, 71% to 88%). Freedom from reoperation was 89% (CI, 76% to 95%) at 5 years. CONCLUSIONS: Cardiac transplantation for hypoplastic left-heart syndrome has a significant positive impact on the natural history of this uniformly lethal lesion.

Cohort Studies↗
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Indications and contraindications for heart transplantation in infancy.

Heart transplantation uniquely offers infants with irreversible myopathies and complex congenital heart disease (CCHD) the potential for survival. Heart transplantation in the first year of life has an actuarial 1-year survival rate of 85%. Controlling for the variables that lead to perioperative death can improve 1-year survival rates to 95%. Mortality is also accrued before transplantation, with 15% to 20% of infants dying before a donor organ is available. Because of this cumulative mortality, an algorithm was developed to maximize pre- and posttransplantation survival and thus increase the likelihood that the limited donor supply would have the greatest impact. The risk factors considered in the algorithm include: (1) hemodynamic stability, (2) central venous access/prostaglandin requirements, (3) need for ventilator support, (4) pulmonary blood flow dependent on a critically restricted atrial septal defect, (5) risk for pulmonary hypertension, (6) anomalous pulmonary venous return, and (7) history of sepsis. Overall, patient survival would be maximized by only using transplantation for patients with CCHD who have moderate or less risk of pre- or posttransplantation death (< 20%). Donor organ utilization could be maximized by reserving transplantation for patients without options (myopathies) and for patients with CCHD who have a low predicted risk of death (< 10%). Because the risks of death at transplantation or in the first year after transplantation are low and relatively fixed, changes in risks of palliative surgery or donor availability can be easily used to adjust the decision algorithm.

Contraindications↗
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Heart transplantation techniques in complex congenital heart disease.

Of 207 pediatric patients who underwent orthotopic heart transplantation at Loma Linda University Medical Center through January 1993, 96% of infants under 6 months of age and 45% of older infants and children had complex structural heart disease. Twelve patients had visceral heterotaxia, 10 had isolated dextrocardia, and 16 had unusual atrial situs, including five with situs inversus. Therefore a prerequisite for successful heart transplantation in early life is a surgical team skilled in the management of congenital heart disease. Transplantation in very early life is usually primary therapy, whereas in older infants and children it is an exercise in reoperative and reconstructive heart surgery. The keys to operative success include the following: (1) Appropriate recipient selection; (2) en bloc recovery of all veins and arteries required for anatomic reconstruction; (3) adequate myocardial protection; and (4) use of low-flow hypothermic perfusion and intermittent circulatory arrest as required. Although there is wide variability in the anatomic presentation of many potential recipients with congenital heart disease, only two absolute anatomic contraindications have been identified. Absence or marked hypoplasia of central pulmonary arteries and absence or markedly diminutive pulmonary veins are two anatomic variants that do not yield to heart transplantation therapy. Previous palliative surgery, variations of atrial situs, anomalies of pulmonary or systemic venous connections, and great vessel malformations all create challenge for the surgical team and potential risk for the recipient, but none preclude operative success.

Child↗
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Methotrexate as rescue/adjunctive immunotherapy in infant and adult heart transplantation.

Methotrexate may be a useful adjunct to more conventional immunosuppression in heart transplantation, but experience is limited. We report our findings in 18 patients aged 19 days to 64 years, who were treated with methotrexate. Five patients were less than 1 year of age; 11 patients were over 16 years of age. Indications could be divided in two groups. Seven patients were treated with methotrexate as rescue therapy for unresolving acute grade 3 rejection or for early recurrence after one rejection episode that had been treated with steroids and antilymphocyte serum. All infants were treated with methotrexate for life-threatening rejection. Methotrexate was given as an adjunct to conventional treatment in six patients for mild rejection, which occurred while steroids were being decreased or in patients with relative contraindications to high-dose steroids. One grade 3b rejection could not be reversed with methotrexate and led to the patient's death 3 months later. One grade 1b rejection only temporarily improved and was actually reversed with high-dose steroids after 4 months. All other rejections were rapidly reversed with the use of methotrexate. Tolerance of methotrexate has been very good with transient leukopenia in four patients, with ulcerative stomatitis in one patient, and with transient elevation of liver enzymes in two patients. We conclude that methotrexate is a valuable rescue/adjunctive immunotherapeutic agent that is capable of altering heart rejection with considerable safety and efficacy.

Adolescent↗
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Prolonged preservation of human pediatric hearts for transplantation: correlation of ischemic time and subsequent function.

Ninety-one infants and children, aged 0 days to 12 years, who received 93 hearts from donors aged 2 days to 24 years between November 1985 and September 1990 were retrospectively studied. Forty-three children were less than 1 month of age; 31 children were between 1 month and 6 months of age, and 19 children were between 6 months and 12 years of age. The donor heart ischemic time ranged from 51 minutes to 8 hours 17 minutes (mean, 4 hours 2 minutes). Fifty-one hearts had an ischemic time of less than 4 hours (group 1), and 42 hearts, more than 4 hours (group 2). No significant difference was noted in the age of donor or recipient or in donor/recipient weight ratio. No correlation was found between ischemic time and number of primary graft failures between groups. Inotropic support was required for 3.9 +/- 3.3 and 5.2 +/- 3.7 days for group 1 versus group 2 (not significant). Ventilator status was the same between the groups. A significant decrease of posterior wall movement in diastole (p < 0.01) occurred among patients of group 2 at 1 week after transplantation, but no difference was found between groups at 2 weeks, 1 month, and 3 months after operation. Posterior wall movement of group 2 heart grafts recovered completely by week 2. No difference was noted in the fractional shortening between the groups; but in both groups, fractional shortening significantly increased from week 1 to week 2. We conclude that ischemic times up to nearly 8 1/2 hours are well tolerated by donor hearts used in pediatric transplantation.

Age Factors↗
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Utilization of pediatric donors salvaged by cardiopulmonary resuscitation.

The efficacy of using infant donors with an extended cardiopulmonary resuscitation (CPR) history was investigated. Eight heart transplantations with donors who had no or minimal (less than 10 minutes) history of CPR (group A) and seven heart transplantations with donors with extended CPR history (35 to 125 minutes; mean, 59 minutes; group B) were compared for peak myosin levels after transplantation, and systolic and diastolic cardiac function in the first week after transplantation. All donor hearts had normal hemodynamics in the early postoperative period. No significant differences were found between the groups with regard to age of donors, age of recipients, donor heart ischemic time, and cardiac function in the first week after transplantation. In group B, peak myosin levels were 1.4, 4.6, 7.0, 11.3, 14.8, 20.2, and 21.3 ng/ml. These values were significantly (p < 0.05) higher than those in group A but represented only minimal myocardial damage when compared with the values in previous myocardial infarction studies. Although donors with a history of protracted CPR had higher efflux of myosin light chains perioperatively, hemodynamic recovery suggests that use of pediatric donor heart grafts after prolonged CPR is safe and efficacious.

Age Factors↗