Comparison of allografts and prosthetic valves when used for emergency aortic valve replacement for active infective endocarditis

Aortic valve replacement (AVR) using allografts is an established method of treating aortic valve disease. It is uncertain, however, whether the increased technical demands of allograft AVR can be justified in emergency operations. This study reports 15 patients treated between 1987 and 1990 for acute bacterial or fungal endocarditis involving the aortic valve. Patients underwent emergency AVR because of severe congestive failure, overwhelming sepsis or cerebral emboli. Eight patients received prosthetic valves (group I: 4 mechanical, 4 porcine) and 7 received human allografts (group II: 5 aortic and 2 pulmonary). The groups were comparable in age (group I, 55 years; group II, 51 years), intravenous drug abuse (group I, 1; group II, 3), and previous AVR (group I, 3; group II, 2). One group I and 4 group II patients had septal abscesses. Additional procedures in group I included mitral valve replacement (2), tricuspid valve replacement (1) and aortic root replacement (1). Additional procedures in group II were mitral valve repair (1), root replacement (1), atrial septal defect closure (1) and aortocoronary bypass (1). Mean bypass times (group I, 189 minutes; group II, 204 minutes) and cross-clamp times (group I; 108 minutes; group II, 121 minutes) were similar. Operative deaths occurred in 4 of 8 group I and 1 of 7 group II patients. All surviving patients have been successfully followed (group I,28 months; group II, 18 months). No group I patient has required reoperation. One group II patient required reoperation for recurrent infection affecting the allograft, and another group II patient died 10 months postoperatively from noncardiac causes. All other group II patients are alive and well with functioning allografts. AVR with allografts can be performed safely in this high-risk patient population.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29163/1/0000208.pd

Echocardiographic evaluation of atrioventricular orifice anatomy in children with atrioventricular septal defect

AbstractIn atrioventricular (AV) septal defect, the common AV valve can have a common orifice or can be divided by bridging leaflet tissue into two separate orifices. To determine the accuracy of a two-dimensional echocardiographic technique devised specifically for evaluation of the number of AV valve orifices, all 69 children undergoing surgical repair of AV septal defect from April 1987 to August 1999 were examined prospectively. The presence of bridging leaflet tissue and the number of AV valve orifices were determined with use of a subcostal imaging plane. From a standard subcostal four-chamber view, the plane of sound was rotated 30 ° to 45 ° clockwise until the AV valve was seen en face. The plane of sound was then tilted from a superior to an inferior direction so that cross-sectional views of the AV valve were examined from the inferior margin of the atrial septum to the superior margin of the ventricular septum.Of the 69 patients, 6 (9%) were excluded because the appropriate subcostal images were not obtained (in 3 because of obesity and in 3 as a result of operator failure). The remaining 63 children, ranging in age from 1 day to 13.5 years and in weight from 1 to 55 kg, constituted the study group. Echocardiographic results were compared with surgical observations in 62 patients and with autopsy findings in 1 patient.With the two-dimensional echocardiographic technique, 32 of 33 patients with a common orifice and 28 of 30 patients with two separate AV valve orifices were correctly identified. By chi-square analysis, the echocardiographic technique allowed correct identification of a common orifice valve with 94% sensitivity and 97% specificity. For correct identification of two separate orifices, the echocardiographic technique had 97% sensitivity and 94% specificity. The positive predictive value of the echocardiographic technique was 97% for a common orifices and 93% for two separate orifices. Thus, in patients with AV septal defect, the presence of bridging leaflet tissue and the number of AV valve orifices can be accurately determined with use of a subcostal two-dimensional imaging plane

Echocardiographic evaluation of atrioventricular orifice anatomy in children with atrioventricular septal defect

AbstractIn atrioventricular (AV) septal defect, the common AV valve can have a common orifice or can be divided by bridging leaflet tissue into two separate orifices. To determine the accuracy of a two-dimensional echocardiographic technique devised specifically for evaluation of the number of AV valve orifices, all 69 children undergoing surgical repair of AV septal defect from April 1987 to August 1999 were examined prospectively. The presence of bridging leaflet tissue and the number of AV valve orifices were determined with use of a subcostal imaging plane. From a standard subcostal four-chamber view, the plane of sound was rotated 30 ° to 45 ° clockwise until the AV valve was seen en face. The plane of sound was then tilted from a superior to an inferior direction so that cross-sectional views of the AV valve were examined from the inferior margin of the atrial septum to the superior margin of the ventricular septum.Of the 69 patients, 6 (9%) were excluded because the appropriate subcostal images were not obtained (in 3 because of obesity and in 3 as a result of operator failure). The remaining 63 children, ranging in age from 1 day to 13.5 years and in weight from 1 to 55 kg, constituted the study group. Echocardiographic results were compared with surgical observations in 62 patients and with autopsy findings in 1 patient.With the two-dimensional echocardiographic technique, 32 of 33 patients with a common orifice and 28 of 30 patients with two separate AV valve orifices were correctly identified. By chi-square analysis, the echocardiographic technique allowed correct identification of a common orifice valve with 94% sensitivity and 97% specificity. For correct identification of two separate orifices, the echocardiographic technique had 97% sensitivity and 94% specificity. The positive predictive value of the echocardiographic technique was 97% for a common orifices and 93% for two separate orifices. Thus, in patients with AV septal defect, the presence of bridging leaflet tissue and the number of AV valve orifices can be accurately determined with use of a subcostal two-dimensional imaging plane

Pulmonary function after modified venovenous ultrafiltration in infants: A prospective, randomized trial

AbstractObjective: We sought to examine the effects of modified venovenous ultrafiltration after cardiopulmonary bypass on pulmonary compliance in infants. Methods: We prospectively enrolled 38 infants undergoing their first operation for congenital heart disease. Infants were randomized to receive 20 minutes of modified ultrafiltration after bypass or control. Static and dynamic compliance was measured after induction of anesthesia, before and immediately after filtration in the operating theater, 1 hour after return to the pediatric intensive care unit, and 24 hours after the operation. Length of time on the ventilator, inotropic requirements, and length of stay in the intensive care unit were recorded. Results: Modified ultrafiltration produced a significant immediate improvement in dynamic (pre-ultrafiltration 2.5 ± 1.9 mL/cm H2O to post-ultrafiltration 2.9 ± 2.7 mL/cm H2O, P = .03) and static (pre-ultrafiltration 2.1 ± 0.9 mL/cm H2O to post-ultrafiltration 2.9 ± 2.1 mL/cm H2O, P = .04) compliance. However, there was no significant difference in the change in dynamic (P = .3) or static (P = .7) compliance in the ultrafiltration and control groups when compared before the operation, after the operation, and at 24 hours. There was no significant difference in the time to extubation between patients and control subjects (140 ± 91 hours vs 90 ± 58 hours) or the length of intensive care unit stay (10.0 ± 9.1 days vs 7.4 ± 5.7 days). Conclusions: Modified ultrafiltration produces an improvement in pulmonary compliance after bypass in infants. However, these improvements are not sustained past the immediate post-ultrafiltration period and do not lead to a decreased length of intubation or intensive care unit stay. (J Thorac Cardiovasc Surg 2000; 119:501-7

Echocardiographic predictors of the need for infundibular wedge resection in infants with aortic arch obstruction, ventricular septal defect and subaortic stenosis

Infants with aortic arch obstruction and outlet ventricular septal defect can have posterior displacement of the infundibular septum into the left ventricular outflow tract causing varying degrees of subaortic stenosis.1-3 Because of the large ventricular septal defect, left ventricular outflow tract velocities are frequently normal. For this reason, Doppler peak gradients are often not helpful for assessing the severity of the outflow tract narrowing preoperatively. Preoperative evaluation of the degree of subaortic obstruction and, thus, the need for surgical intervention is usually based on qualitative assessment of the anatomic 2-dimensional echocardiographic image.2-6 This study defines 2-dimensional echocardiographic predictors of the need for subaortic resection in infants with aortic arch obstruction, outlet ventricular septal defect and posterior deviation of the infundibular septum.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29683/1/0000010.pd

Doppler forward flow profiles of St. Jude Medical prosthetic valves in pediatric patients

In summary, this data on baseline and follow-up Doppler flow characteristics of small caliber SJM prosthetic valves should be extremely valuable for identifying valve dysfunction in children. Because of the high risk of developing valve obstruction, these children should be closely monitored with serial Doppler examinations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31454/1/0000375.pd

Calcification of Rat Valve Allografts

Scanning electron microscopy (SEM) and energy dispersive X-ray microanalysis (EDS) have been used to quantify calcium deposition in bioprosthetic valves. To further characterize the calcification process as it pertains to allograft valve tissue, two models of tissue valve implantation were used. The first model used subcutaneous implantation of glutaraldehyde-preserved allogeneic aortic and pulmonary valve leaflets. The second model used syngeneic or allogeneic fresh aortic valve grafts implanted heterotopically into the abdominal aorta of recipient rats. Reference light microscopy was used to select sections for SEM and EDS. In the subcutaneous model, calcium content in both the pulmonary and aortic valves increased up to three weeks, followed by a plateau. The pulmonary leaflets showed greater calcium content than aortic leaflets. In the heterotopic implantation study, calcification occurred to a significantly greater degree in the allogeneic than in the syngeneic valves. This technique may be useful in analyzing the factors that contribute to deterioration of bioprosthetic and allograft valves

Vascular endothelial growth factor and basic fibroblast growth factor in children with cyanotic congenital heart disease

AbstractObjective: Vascular endothelial growth factor and basic fibroblast growth factor are potent stimulators of angiogenesis. Children with cyanotic congenital heart disease often experience the development of widespread formation of collateral blood vessels, which may represent a form of abnormal angiogenesis. We undertook the present study to determine whether children with cyanotic congenital heart disease have elevated serum levels of vascular endothelial growth factor and basic fibroblast growth factor. Methods: Serum was obtained from 22 children with cyanotic congenital heart disease and 19 children with acyanotic heart disease during cardiac catheterization. Samples were taken from the superior vena cava, inferior vena cava, and a systemic artery. Vascular endothelial growth factor and basic fibroblast growth factor levels were measured in the serum from each of these sites by enzyme–linked immunosorbent assay. Results: Vascular endothelial growth factor was significantly elevated in the superior vena cava (P = .04) and systemic artery (P = .02) but not in the inferior vena cava (P = .2) of children with cyanotic congenital heart disease compared to children with acyanotic heart disease. The mean vascular endothelial growth factor level, determined by averaging the means of all 3 sites, was also significantly elevated (P = .03). Basic fibroblast growth factor was only significantly elevated in the systemic artery (P = .02). Conclusion: Children with cyanotic congenital heart disease have elevated systemic levels of vascular endothelial growth factor. These findings suggest that the widespread formation of collateral vessels in these children may be mediated by vascular endothelial growth factor. (J Thorac Cardiovasc Surg 2000;119:534-9

Usefulness of the bidirectional Glenn procedure as staged reconstruction for the functional single ventricle

The bidirectional Glenn operation may be particularly useful as an intermediate procedure before Fontan correction in high-risk patients. From October 1989 through February 1992, 50 patients 1 to 60 months old (median 12) have undergone a bidirectional Glenn operation. Diagnoses included hypoplastic left heart syndrome in 21 patients, pulmonary atresia with intact ventricular septum in 10, tricuspid valve atresia in 9, other complex univentricular heart defects in 9, and Ebstein's anomaly in 1. Mean pulmonary vascular resistance was 2.2 +/- 0.2 Wood U (range 0.5 to 7.3) and mean pulmonary artery area Nakata index was 318 +/- mm2/m2 (range 80 to 821). Additional procedures were performed in 17 patients, including pulmonary artery reconstruction in 15 (29%) and bilateral caval anastomoses in 5 (10%). There were 4 hospital deaths (8%). Two deaths resulted from myocardial infarction in patients with pulmonary atresia with intact ventricular septum and sinusoids and 1 from severe pulmonary vascular disease in a patient with hypoplastic left heart syndrome. There was 1 late death from pneumonia. Actuarial survival is 92 +/- 4% at 1 month and beyond, with a mean follow-up of 13.4 +/- 1 months. Risk factor analysis showed that pulmonary vascular resistance >3 Wood U and pulmonary artery distortion were associated with increased mortality. Twelve patients have undergone a Fontan procedure at a mean duration after bidirectional Glenn of 18 months with 1 death (8%). The bidirectional Glenn procedure provides excellent palliation in high-risk patients and appears useful as a staging procedure before Fontan correction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30841/1/0000503.pd