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Biomedical subjects

Anthony Azakie

Publications and source records attributed to Anthony Azakie.

27 records · Page 2Linked to original sources
PubMed2004

Impact of right ventricle to pulmonary artery conduit on outcome of the modified Norwood procedure.

BACKGROUND: To determine and compare outcome of the modified Norwood procedure using either a systemic to pulmonary artery (SPA) shunt or right ventricle to pulmonary artery (RV-PA) conduit in a consecutive series of neonates at a single institution. METHODS: The medical records were retrospectively examined for preoperative demographic and echocardiographic data, operative variables, and postoperative clinical and hemodynamic data. From November 2001 to March 2003, 21 neonates had a modified Norwood procedure (SPA shunt, n = 8; RV-PA conduit, n = 13) at a median age of 5 days (range 1 to 18 days) and a median weight of 2.9 kg (range 1.7 to 4.1 kg). Of the 21 infants, 12 were considered high risk due to presence of low birth weight (n = 4), extracardiac or genetic anomalies (n = 5) or obstruction to pulmonary venous return (n = 5). Nine "high risk" infants were in the RV-PA conduit group. RESULTS: Overall Norwood operation survival was 90% (19/21) and did not differ between groups. There were 2/19 interstage deaths and Kaplan-Meier survival at 1 year is 79%. Neonates in the RV-PA conduit group had significantly higher diastolic blood pressures at 1, 6, and 24 hours postoperatively (p < 0.05). Neonates in the SPA shunt group had significantly higher heart rates at 1 hour postoperatively (p < 0.05) than those in the RV-PA group. There was a trend to higher number of ventilatory interventions to balance Qp:Qs in the SPA shunt group (p = 0.06). CONCLUSIONS: In a relatively high-risk group, neonates having an RV-PA conduit as part of the Norwood procedure have favorable postoperative hemodynamics and a good likelihood of stage I survival.

Blood Vessel Prosthesis Implantation↗
PubMed2004

Preoperative brain injury in newborns with transposition of the great arteries.

BACKGROUND: The objective was to determine the timing and mechanism of brain injury using preoperative and postoperative magnetic resonance imaging (MRI) and three-dimensional MR spectroscopic imaging (MRSI) in newborns with transposition of the great arteries (TGA) repaired with full-flow cardiopulmonary bypass. METHODS: Ten term newborns with TGA undergoing an arterial switch operation were studied with MRI, MRSI, and neurologic examination preoperatively and postoperatively at a median of 5 days (2 to 9 days) and 19 days (14 to 26 days) of age, respectively. Five term historical controls were studied at a median of 4 days (3 to 9 days). Lactate/choline (marker of cerebral oxidative metabolism) and N-acetylaspartate (NAA)/choline (marker of cerebral metabolism and density) were measured bilaterally from the basal ganglia, thalamus, and corticospinal tracts. RESULTS: Four TGA newborns had brain injury on the preoperative MRI. The only new lesion detected on the postoperative study was a focal white matter lesion in one newborn with a normal preoperative MRI. The MRSI of age-adjusted lactate/choline was quantitatively higher in newborns with TGA compared with those without heart disease (p < 0.0001), even in newborns without MRI evidence of preoperative brain injury. Lactate/choline decreased after surgery but remained elevated compared with controls. In newborns with TGA, those with preoperative brain injury on MRI had lower NAA/choline globally (p = 0.04) than those with normal preoperative MRI. Five newborns had a decline in NAA/choline from the preoperative to postoperative studies. CONCLUSIONS: Abnormal brain metabolism and injury was observed preoperatively in newborns with TGA. Brain injury is not solely related to the operative course.

Brain Injuries↗
PubMed2004

Immature intrapericardial teratoma in a newborn with elevated alpha-fetoprotein.

A large intrapericardial mass was incidentally found in a fetus at 32 weeks gestational age, which was accompanied by a significant pericardial effusion. The baby was delivered by cesarean section and had surgical removal of the tumor on the second day of life. Alpha-fetoprotein was elevated. The pathologic analysis demonstrated a grade I immature teratoma with foci of hepatoid tissue. The patient had an uneventful postoperative recovery. A review of the literature and pathologic implications are discussed.

Adult↗
PubMed2004

Associated factors and trends in outcomes of interrupted aortic arch.

BACKGROUND: Interrupted aortic arch (IAA) continues to be associated with important mortality, both before and immediately after repair, with ongoing morbidity during follow-up. We sought to determine trends in presentation, management, outcomes and associated factors. METHODS: We reviewed all consecutive patients (n = 119) presenting from 1975 to 1999, and data were collected regarding demographics, anatomy, management and outcomes. RESULTS: Significant trends over time for patients born in three consecutive periods (1975 to 1984, 1985 to 1993, and 1994 to 1999) demonstrated a smaller proportion of patients with presentation with circulatory collapse (65%, 51%, and 25%, respectively), greater use of prostaglandins (72%, 90%, 100%), fewer deaths without IAA repair (49%, 15%, 13%) and greater use of one-stage repair (68%, 75%, 100%). Independent risk factors for death without IAA repair (p < 0.001) included absence of ventricular septal defect, and the presence of noncardiac anomaly, complex cardiac anomaly, episode of acidosis and earlier birth cohort. Overall survival after repair was 50% at age 1 month, 35% at 1 year, and 34% at 5 years. Early and constant-hazard phases were noted, with incremental risk factors for early phase mortality being cyanosis at presentation, presence of truncus arteriosus or aortic stenosis, an episode of circulatory collapse before repair, earlier date of repair, and lower weight at repair. Greatest survival occurred in those patients with uncomplicated IAA who had repair since 1993 (5 year survival, 83%). Freedom from reintervention for arch obstruction was 60% at 5 years. CONCLUSIONS: While improving, outcomes of IAA remain of concern, especially in patients with associated lesions.

Abnormalities, Multiple↗
PubMed2004

Effect of chamber capacitance on Doppler flow pattern across restrictive defects in obligatory atrial-level shunts.

The right atrium has a significantly higher capacitance than the left atrium, and this may affect the Doppler flow pattern across an atrial septal defect (ASD) in unilateral atrioventricular (AV) valve atresia. This Doppler flow pattern is often used to assess ASD adequacy in this setting. We studied the effect of atrial capacitance and ASD size on the trans-ASD Doppler flow pattern in an in vivo flow model of alternate left or right AV valve atresia (LAVVA and RAVVA). We assessed trans-ASD Doppler flow patterns using the max/min velocity ratio and mean interatrial pressure gradients (PGs). In both models, ASD flow rate correlated with mean trans-ASD PG, but for similar flow rates the slope was higher in the LAVVA model. In LAVVA, a persistent PG was consistently observed, with low max/min ratio (median, 1.46; range, 1.03-3.13), whereas in RAVVA, phasic flow was common (median, 8.0; range, 2.8-20). Because atrial capacitance affects mean PG and Doppler flow pattern across the ASD, we propose that the assessment of ASD adequacy in RAVVA should not rely on Doppler findings.

Animals↗
PubMed2004

Outcomes of mitral valve replacement in children: a competing-risks analysis.

OBJECTIVE: We sought to define patient characteristics, outcomes, and associated factors after mitral valve replacement in children. METHODS: We included 104 children undergoing at least one mitral valve replacement between 1980 and 2003 and reviewed clinical records. Competing-risks methodology was used to determine time-related prevalence and associated risk factors after initial mitral valve replacement for death and repeat replacement. RESULTS: The underlying mitral valve disease was congenital in 83%, rheumatic in 13%, Marfan syndrome in 3%, and isolated endocarditis in 1%, with 64% having primarily regurgitation, 16% having stenosis, 20% having both, and 32% having undergone previous valvotomy, valvuloplasty, or repair. There were 137 valve replacements, with 26 patients having more than one. Valve prosthesis type was St Jude Medical in 37%, Bjork-Shiley in 25%, Carbomedics in 20%, Ionescu-Shiley in 10%, and other types in 8%. Both early and late complications were common. Median age at the initial replacement was 5.9 years (range, birth to 19 years). Competing-risks analysis predicted 19% to have died at 15 years after initial replacement, with risk factors including noncongenital valve morphology, lower weight, and longer duration of cardiopulmonary bypass. A repeat replacement was predicted for 71%, with risk factors including the presence of multiple left-heart obstructive lesions and Ionescu-Shiley valve prosthesis. CONCLUSIONS: Mitral valve replacement might be necessary in children with extremely dysplastic valves and severe hemodynamic impairment or after failed repair. However, with the appropriate selection of the prosthetic valve and reduction of cardiopulmonary bypass time, surgeons might decrease mortality and increase prosthesis longevity.

Adolescent↗
PubMed2003

Anatomic repair of anomalous left coronary artery from the pulmonary artery by aortic reimplantation: early survival, patterns of ventricular recovery and late outcome.

BACKGROUND: To determine the early and late outcomes of patients presenting with anomalous left coronary artery from the pulmonary artery who had repair by aortic reimplantation. METHODS: From January 1952 to July 2000, 67 patients presented with anomalous coronary artery from the pulmonary artery. Forty-seven patients who had repairs performed by aortic reimplantation are the subject of this study. The median age at repair was 7.7 months. Before repair, 10 infants (21%) presented in extremis requiring ventilatory and inotropic support, and 38 infants (80%) presented in heart failure. Autologous pericardial hood coronary arterioplasty was used in 4 patients, and concomitant mitral valve repair was used in 1 patient. RESULTS: Hospital survival was 92%. Five children required postoperative extracorporeal membrane oxygenation for a median of 4 days (range, 2 to 8 days). Patients who had extracorporeal membrane oxygenation were significantly more likely to have presented in critical condition (40% vs 3% if no extracorporeal membrane oxygenation; p = 0.006) or with ventricular arrhythmias (67% vs 7%; p = 0.027), to have presented with significantly lower preoperative repair median ejection fraction (10%, n = 5 vs 40%, n = 38; p = 0.01) or to have presented with more severe left ventricular dilatation (p = 0.03). Within a 15-year or less follow-up (mean, 4.7 years) there were no late deaths. Kaplan-Meier survival was 91% at 5 years, and freedom from reoperation was 93% at 10 years. At late follow-up, echocardiography demonstrated significant improvements in mean ejection fraction (64% +/- 9% vs 33% +/- 21% preoperatively, p < 0.0001); moderate mitral regurgitation (9% vs 38% preoperatively, p < 0.02); and wall motion abnormalities (15% vs 81% preoperatively, p < 0.002). The ratio of measured left ventricular end-diastolic dimension to the 95th percentile of normal declined from 1.4 +/- 0.3 to 1.0 +/- 0.1 (p < 0.0006). Children who had extracorporeal membrane oxygenation had normal ejection fractions and ventricular dimensions at follow-up (n = 3). Repeated measures of mixed linear regression analysis demonstrated that normalization of ejection fraction and left ventricular function occurred within 1 year of repair. Improvements in mitral regurgitation lagged behind normalization of ejection fraction and left ventricular dilatation. CONCLUSIONS: Anatomic repair of anomalous left coronary artery from the pulmonary artery by aortic reimplantation yields excellent early survival and late functional outcomes even in critically ill infants.

Adolescent↗
PubMed2002

Alterations in ET-1, not nitric oxide, in 1-week-old lambs with increased pulmonary blood flow.

Altered pulmonary vascular reactivity is a source of morbidity and mortality for children with congenital heart disease and increased pulmonary blood flow. Nitric oxide (NO) and endothelin (ET)-1 are important mediators of pulmonary vascular reactivity. We hypothesize that early alterations in endothelial function contribute to the altered vascular reactivity associated with congenital heart disease. The objective of this study was to characterize endothelial function in our lamb model of increased pulmonary blood flow at 1 wk of life. Eleven fetal lambs underwent in utero placement of an aortopulmonary vascular graft (shunt) and were studied 7 days after delivery. The pulmonary vasodilator response to both intravenous ACh (endothelium dependent) and inhaled NO (endothelium independent) was similar in shunted and control lambs. In addition, tissue NO(x), NO synthase (NOS) activity, and endothelial NOS protein levels were similar. Conversely, the vasodilator response to both ET-1 and 4Ala-ET-1 (an ET(B) receptor agonist) were attenuated in shunted lambs, and tissue ET-1 concentrations were increased (P < 0.05). Associated with these changes were an increase in ET-converting enzyme-1 protein and a decrease in ET(B) receptor protein levels (P < 0.05). These data demonstrate that increased pulmonary blood flow induces alterations in ET-1 signaling before NO signaling and suggest an early role for ET-1 in the altered vascular reactivity associated with increased pulmonary blood flow.

Acetylcholine↗