Current Status of Staged Reconstruction for Hypoplastic Left Heart Syndrome

Once considered a uniformly fatal condition, the outlook for newborns with hypoplastic left heart syndrome has been dramatically altered with staged reconstructive procedures. Refinements in operative technique and perioperative management have been largely responsible for this improved outlook. At the University of Michigan, 253 patients underwent the Norwood operation for classic hypoplastic left heart syndrome between January 1990 and November 1997. Hospital survival was 76%. Among patients considered at standard risk, survival was significantly higher (86%) than that for those patients with important risk factors (42%, p = 0.0001). Adverse survival was most strongly associated with significant associated noncardiac congenital conditions ( p = 0.008) and severe preoperative obstruction to pulmonary venous return ( p = 0.03). Survival following second-stage reconstruction with a hemi-Fontan or bidirectional Glenn procedure was 97%. The Fontan procedure has been completed in 94 of these patients with a hospital survival rate of 88%. Survival after the Fontan procedure improved significantly when the second stage of the reconstruction was completed with a hemi-Fontan procedure compared to a bidirectional Glenn (98% vs 81%, p = 0.05). Among the patients considered at standard risk, actuarial survival was 70% at 5 years. The largest decrease in survival occurred in the first month of life and late deaths affected primarily those patients in the high-risk group. Neurodevelopmental outcome studies demonstrated normal verbal and performance scores in the majority of patients. Staged reconstruction has significantly improved the intermediate-term outlook for patients with hypoplastic left heart syndrome. Factors addressing improvements in early first-stage survival would be expected to add significantly to an overall improved late outcome.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42378/1/246-19-4-308_19n4p308.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

Hypothermic cardiopulmonary bypass: A comparison between alpha and pH stat regulation in the dog

The accepted normal pH of 7.40 may not be optimal at lower temperatures. This study evaluated the effect of maintaining pH in the accepted normal range at hypothermia (group 1, pH stat) or at normothermia (group 2, alpha stat) on organ blood flow and hemodynamics in dogs. The desired pH was achieved at all temperatures by adjusting pCO2. Hypothermia to 20[deg]C was induced by high flow bypass in both groups followed by 45 min of reduced flow before rewarming. In group 1 (n = 10), pH was 7.45 +/- 0.02 at 20[deg]C and in group 2 (n = 11) it was 7.64 +/- 0.01. A greater base excess developed by the end of the low flow period in pH stat animals (-9.4 +/- 1.1 vs -2.8 +/- 0.8, P P P P P P P P pCO2 control between alpha and pH stat regulation assume lesser importance for regional blood flow when normal systemic flow is maintained during cooling and rewarming.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26870/1/0000435.pd

Outcomes of 1½- or 2-ventricle conversion for patients initially treated with single-ventricle palliation

ObjectiveAs outcomes for the Fontan procedure have improved, it has become more difficult to select between a single-ventricle repair or biventricular repair for patients with complex anatomy and 2 ventricles. However, late complications after the Fontan procedure remain a concern. Our strategy, which has favored an aggressive preferential approach for biventricular repair in these patients, has also been applied to patients initially treated on a single-ventricle track elsewhere.MethodsNine patients (4 male patients) who had previously undergone the Fontan procedure (n = 3) or bidirectional cavopulmonary shunting (n = 6) with intent for a later Fontan procedure were referred to our center for complex 1½- or 2-ventricle repair over the last 10 years. Indications for conversion in these patients were protein-losing enteropathy (n = 2), pulmonary arteriovenous malformation (n = 1), and preference for biventricular anatomy (n = 6). The conversion mainly consisted of takedown of the Fontan procedure or bidirectional cavopulmonary shunt connection, reconstruction of 1 or both of venae cavae, creation of an intraventricular pathway for left ventricular output, and placement of a right ventricle–pulmonary artery conduit (Rastelli-type operation).ResultsFive patients underwent 1½-ventricle repair, and 4 had complete biventricular repair. Median cardiopulmonary bypass and aortic crossclamp times were 202 minutes (range, 169–352 minutes) and 129 minutes (range, 100–168 minutes), respectively. There were 2 early deaths and 1 late death. At a median follow-up of 27 months (range, 3.3–99.8 months), all survivors are in New York Heart Association class I.ConclusionsPatients initially treated with intent to perform single-ventricle palliation can be converted to 1½- or 2-ventricle physiology with acceptable outcomes

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

Early Surgical Morbidity and Mortality in Adults with Congenital Heart Disease: The University of Michigan Experience

Objectives.  To review early surgical outcomes in a contemporary series of adults with congenital heart disease (CHD) undergoing cardiac operations at the University of Michigan, and to investigate possible preoperative and intraoperative risk factors for morbidity and mortality. Methods.  A retrospective medical record review was performed for all patients ≥18 years of age who underwent open heart operations by a pediatric cardiothoracic surgeon at the University of Michigan Congenital Heart Center between January 1, 1998 and December 31, 2004. Records from a cohort of pediatric patients ages 1–17 years were matched to a subset of the adult patients by surgical procedure and date of operation. Results.  In total, 243 cardiac surgical operations were performed in 234 adult patients with CHD. Overall mortality was 4.7% (11/234). The incidence of major postoperative complications was 10% (23/234) with a 19% (45/23) minor complication rate. The most common postoperative complication was atrial arrhythmias in 10.8% (25/234). The presence of preoperative lung or liver disease, prolonged cardiopulmonary bypass and aortic cross clamp times, and postoperative elevated inotropic score and serum lactates were significant predictors of mortality in adults. There was no difference between the adult and pediatric cohorts in terms of mortality and morbidity. Conclusions.  The postoperative course in adults following surgery for CHD is generally uncomplicated and early survival should be expected. Certain risk factors for increased mortality in this patient population may include preoperative presence of chronic lung or liver dysfunction, prolonged cardiopulmonary bypass and aortic cross-clamp times, and postoperative elevated inotropic score and serum lactate levels.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75596/1/j.1747-0803.2008.00170.x.pd

ATP precursor depletion and postischemic myocardial recovery

Although cardioplegia reduces myocardial metabolism during ischemia, adenosine triphosphate (ATP) depletion occurs, which may contribute to poor functional recovery after reperfusion. Augmenting myocardial adenosine during ischemia is successful in improving ATP repletion and myocardial recovery following ischemia. If adenosine is an important determinant of ischemic tolerance, then depletion or elimination of myocardial adenosine should lead to poor functional and metabolic recovery after ischemia. To test this hypothesis, isolated, perfused rabbit hearts were subjected to 120 min of 34[deg]C ischemia. Hearts received St. Thomas cardioplegia alone or cardioplegia containing 200 [mu]M adenosine, or cardioplegia containing 15, 5, 2.5, or 0.025 [mu]g/ml adenosine deaminase (ADA), which catalyzes the breakdown of adenosine to inosine, making adenosine unavailable as an ATP precursor. Functional recovery was determined and myocardial nucleotide levels were measured before, during, and after ischemia. Following ischemia and reperfusion, control hearts recovered to 51 +/- 3% of preischemic developed pressure (DP). There was significantly better recovery in adenosine-augmented hearts (68 +/- 7%), while ADA hearts had significantly worse recovery. Hearts treated with 0.025 [mu]g/ml ADA recovered to only 29 +/- 5% of DP and higher dose ADA hearts failed to demonstrate any recovery of systolic function. Furthermore, adenosine enhanced metabolic recovery, whereas ADA resulted in greatly depleted ATP and precursor reserves. Postischemic developed pressure closely paralleled the availability of myocardial adenosine, consistent with the hypothesis that myocardial adenosine levels at end ischemia and early reperfusion are important determinants of functional recovery after global ischemia.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29313/1/0000378.pd

Biventricular repair for aortic atresia or hypoplasia and ventricular septal defect

AbstractObjective: Aortic valve atresia or hypoplasia can present with a ventricular septal defect and a normal mitral valve and left ventricle. These patients may be suitable for biventricular repair, although the optimal initial management strategy remains unknown. Methods: From January 1991 through March 1999, 20 patients with aortic atresia or hypoplasia and ventricular septal defect underwent operation with the intent to achieve biventricular repair. Aortic atresia was present in 7 patients, and aortic valve hypoplasia was present in 13 patients. Among those patients with aortic hypoplasia, Z-scores of the aortic valve anulus ranged from –8.8 to –2.7. Associated anomalies included interrupted aortic arch (n = 12 patients), coarctation (n = 6 patients), aortopulmonary window (n = 1 patient), and heterotaxia (n = 1 patient). Nine patients were staged with an initial Norwood procedure followed by biventricular repair in 8 patients. One patient awaits biventricular repair after a Norwood procedure. The conditions of 11 patients were corrected with a single procedure. Results: Among the 9 patients who underwent staged repair, there were no deaths after the Norwood procedure and 1 death after biventricular repair. For the 11 patients who underwent a primary biventricular repair, there was 1 early death and 2 late deaths from noncardiac causes. Follow-up ranged from 1 to 85 months (mean, 28 months). Actuarial survival for the entire group was 78% ± 10% at 5 years and was not significantly different between staged repair (89%) and primary biventricular repair (73%). Conclusions: Both primary and staged biventricular repair for patients with aortic atresia or hypoplasia and ventricular septal defect may be performed with good late survival. Refinements in technique of conduit insertion and arch reconstruction have resulted in primary biventricular repair becoming our preferred approach. (J Thorac Cardiovasc Surg 1999;118:648-54

Aortopulmonary Window with Interrupted Aortic Arch and Pulmonary Artery Sling: Diagnosis by Echocardiography and Magnetic Resonance Imaging: Case Report and Literature Review

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71570/1/j.1540-8175.1999.tb00796.x.pd