Jeanne M. Baffa

Right Ventricle to Pulmonary Artery Conduit Improves Outcome After Stage I Norwood for Hypoplastic Left Heart Syndrome

Background—Diastolic run off into the pulmonary circulation and labile coronary perfusion are thought to contribute to morbidity and mortality after the Norwood procedure (NP). We compared outcomes from the use of a RV to PA conduit (RV/PA) or a modified Blalock-Taussig shunt (BTS), physiologically distinct sources of pulmonary blood flow. Methods and Results—Review of 56 consecutive patients who underwent a Norwood procedure with a RV/PA (n=36) or a BTS (n=20) between 2000 and 2002. Median age was 4.5 days (range 1 to 40) and median weight was 3.1 kg (range 1.8 to 4.1). The RV/PA was constructed with a 5-mm conduit. Patients in the BTS group received a 4-mm shunt. Comparisons between RV/PA and BTS groups showed no difference for weight, gestational age, prenatal diagnosis, HLHS variant, associated diagnoses, ascending aortic size, ventricular function, AV valve function, and pulmonary venous obstruction. Operative survival was higher with RV/PA [33/36 (92%) versus 14/20 (70%); P =0.05]. Patients with RV/PA had less need for ventilatory manipulations to balance the Qp/Qs (1/36 v/s 8/20; P =0.001), delayed sternal closure (6/36 v/s 7/20; P =0.001), and extracorporeal support (5/36 v/s 7/20; P =0.036). RV/PA patients had more favorable postoperative hemodynamics: higher diastolic blood pressure without changes in systolic blood pressure at 1, 8, 24, 48 hours after the NP (46.3 v/s 39.5; 47.2 v/s 42.1; 46.1 v/s 37.1; and 47.1 v/s 40.2; all P =0.001). Conclusion—RV/PA simplifies postoperative management and improves hospital survival after NP for HLHS.

Coronary artery abnormalities and right ventricular histology in hypoplastic left heart syndrome

OBJECTIVES To determine whether right ventricular preservation is compromised in any anatomic subgroup of hypoplastic left heart syndrome, we assessed the coronary artery anatomy and myocardial histologic features of 151 postmortem specimens with hypoplastic left heart syndrome. BACKGROUND Although previous studies have shown that coronary artery abnormalities are more prominent in the subgroup of patients who have a patent mitral valve and obstructed aortic valve, it has not been established that these abnormalities compromise right ventricular perfusion. METHODS Eighty-nine specimens with a patent mitral valve and aortic atresia, 52 with mitral and aortic atresia and 10 with patent mitral and aortic valves were examined. Histologic sections of the right ventricle, left ventricle and coronary arteries were obtained from 64 study hearts and 5 control hearts. RESULTS Gross coronary anomalies included coronary-cameral communications (n = 29), single left coronary artery (n = 2), single right coronary artery (n = 1) and tortuosity (n = 19). Coronary-cameral communications and tortuosity were significantly associated with the subgroup that had mitral hypoplasia and aortic atresia. Coronary artery wall thickness relative to lumen diameter was not different among the subgroups. No areas of coronary artery stenosis or interruption were discovered. Although endocardial fibroelastosis of the left ventricle was strongly associated with the mitral hypoplasia and aortic atresia group, the right ventricular histologic findings were similar in all subgroups and were not differentially affected by older age. CONCLUSIONS Although the incidence of coronary abnormalities is greater in patients with mitral hypoplasia and aortic atresia, in this study there was no apparent difference in perfusion of the right ventricle among the anatomic subgroups of hearts with hypoplastic left heart syndrome.

Hypoplastic left heart syndrome: hemodynamic and angiographic assessment after initial reconstructive surgery and relevance to modified Fontan procedure.

After undergoing initial reconstructive surgery for hypoplastic left heart syndrome performed between August 1985 and March 1989, 59 patients (age range 3 to 27 months, mean 13.8 +/- 4.5) underwent elective cardiac catheterization in anticipation of a modified Fontan procedure. Five important hemodynamic and anatomic features considered to be components of successful reconstructive surgery were specifically addressed. 1) Interatrial communication: Only two patients had a measured pressure difference of greater than 4 mm Hg across the atrial septum. 2) Tricuspid valve function: Angiography demonstrated significant tricuspid valve regurgitation in only five patients (moderate in two and severe in three). 3) Aortic arch: Pressure tracings from the right ventricle to the descending aorta revealed a gradient greater than 25 mm Hg in only two patients. 4) Pulmonary vasculature: Ten patients had a calculated pulmonary vascular resistance greater than 4 U.m2; 51 (86%) of the 59 patients had no evidence of distortion (stenosis or hypoplasia) of either the left or the right pulmonary artery. 5) Right ventricular function: Five patients had an end-diastolic pressure in the right ventricle greater than 12 mm Hg and two patients had qualitative assessment of decreased ventricular function. Comparison of catheterization data between survivors and nonsurvivors of the subsequent modified Fontan procedure showed that only significant tricuspid regurgitation is a possible predictor of poor outcome. After first stage reconstructive surgery for hypoplastic left heart syndrome, most survivors have favorable anatomy and hemodynamics at follow-up cardiac catheterization for a subsequent Fontan procedure.

Changes in Right Ventricular Geometry and Heart Rate Early After Hemi-Fontan Procedure

To document and quantitate changes in right ventricular (RV) geometry and heart rate, we prospectively examined 35 consecutive patients with hypoplastic left heart syndrome under steady-state conditions (chloral hydrate sedation) before and after a bidirectional cavopulmonary anastomosis (hemi-Fontan) procedure. Right ventricular end-diastolic volume (RVEDV) was calculated as the product of RV cavity areas in two orthogonal planes divided by RV maximal length in either plane. After the hemi-Fontan procedure, RVEDV decreased by 33% from 33 +/- 13 to 22 +/- 11 mL (mean +/- standard deviation). Indexed RVEDV decreased from 86 +/- 37 to 57 +/- 28 mL/m2. The RV wall thickness at the diaphragm in subcostal frontal view (RVWD) increased by only 11% from 8 +/- 0.2 to 9 +/- 0.2 mm (p = not significant), but RVWD/RVEDV increased by 111% from 0.36 +/- 0.22 to 0.76 +/- 0.69 mm/mL (p = 0.002). The RV anterior wall thickness in subcostal sagittal view (RVWA) increased by only 13% from 7 +/- 0.2 to 8 +/- 0.2 mm (p = not significant), but RVWA/RVEDV increased by 103% from 0.31 +/- 0.20 to 0.63 +/- 0.54 mm/mL (p = 0.002). In 11 of 35 patients (31%), resting heart rate did not change (118 +/- 14 versus 108 +/- 9 beats/min; p = not significant); however, in 24 of 35 patients (69%), heart rate increased significantly (108 +/- 9 versus 127 +/- 10 beats/min; p = 0.05). In conclusion, RV wall thickness is high before the hemi-Fontan procedure and increases slightly in the first postoperative week.(ABSTRACT TRUNCATED AT 250 WORDS)

Hard choices for high-risk patients with critical left ventricular outflow obstruction: contemporary comparison of hybrid versus surgical strategy.

Surgical management of high-risk newborns with critical left ventricular outflow tract obstruction (LVOTO) involves difficult decision making and complex procedures associated with significant morbidity and mortality. We sought to compare the outcomes of the hybrid and surgical strategies for the management of neonates with critical LVOTO considered at high risk in a contemporary nonrandomized cohort. This is a retrospective review of all patients undergoing management of critical LVOTO between January 2001 and December 2008. High-risk conditions included prematurity, low birth weight, and genetic or associated cardiac and noncardiac pathology. Analysis was performed based on intention to treat. Primary and secondary outcomes were operative and 6-month mortality. The cohort included 55 patients (21 hybrid and 34 surgical [31 Norwood, 3 biventricular repair]). The cohort had a median age of 4 (range, 1-62) days, mean weight of 2.7 ± 0.5 kg, and Aristotle comprehensive score of 18.6 ± 2.9. Low birth weight (P = .0007), prematurity (P = .004), and organ dysfunction (P = .04) were risk factors for operative death. Six-month mortality was associated with need for reintervention (P = .017) in the surgical group and history of organ dysfunction (P = .02) or aortic atresia (P = .03) in the hybrid group. Logistic regression identified low birth weight (P = .05; odds ratio [OR], 5.6 [0.9-34.6]), organ dysfunction (P = .05; OR, 4.7 [0.9-22.5]), and non–hypoplastic left heart syndrome (HLHS) diagnosis (P = .03; OR, 0.06 [0.005-0.93]) as predictors of mortality for the entire cohort. No differences in operative and 6-month mortality were detected between management strategies. Although initial surgical insult is lessened by the hybrid palliation, important interstage mortality and ongoing morbidity result in similar 6-month survival with either strategy. Patient-related factors have a larger influence on outcome than the management strategy chosen.

UNEXPECTED LATE CORONARY ARTERY ABNORMALITIES AFTER ARTERIAL SWITCH OPERATION FOR TRANSPOSITION OF THE GREAT ARTERIES

Arterial switch operation (ASO) is a common surgical intervention for d-loop transposition of the great arteries (d-TGA). The incidence of late coronary artery complications may be underestimated due to lack of clinical symptoms and limitations in non-invasive studies. We investigated coronary