Feasibility and safety of biventricular repair in neonates with hypoplastic left heart complex.

Hypoplastic left heart syndrome is a spectrum of structural cardiac malformations characterized by variable underdevelopment of the left heart-aorta complex. A minority of patients having a milder degree of left ventricular hypoplasia, described as hypoplastic left heart complex (HLHC), may be selected for biventricular repair. The objective of this study was to assess the outcome of the biventricular approach in HLHC. We evaluated retrospectively 30 neonates diagnosed with HLHC from the "12 de Octubre" University Hospital, following established criteria. We analyzed the echocardiographic data recorded just after birth and at last follow-up after surgery. All patients were operated on in the neonatal period using various surgical techniques. There were no early deaths and only 1 late death after a mean follow-up of 62.9 ± 43.8 months. All patients presented a significant growth of the left ventricular structures, with a Z-score increase of 1.17 ± 1.05 for mitral annulus, 1.72 ± 1.23 for aortic annulus, and 1.33 ± 1.46 for left ventricular end-diastolic diameter. Postoperatively, 18 patients showed a left valvular stenosis, and 17 patients underwent a reoperation and/or an interventional procedure. Freedom from surgery or interventional catheterizations at 1, 3 and 5 years was 53, 49 and 43%, respectively. The 29 current survivors are all in a good functional status. In our experience, we achieved good results from biventricular repair in patients with HLHC, with a significant growth of left heart structures and an excellent clinical status at a medium-term follow-up. Nevertheless, there was a high rate of reoperations and/or interventional catheterizations.

Identification of de novo mutations and rare variants in hypoplastic left heart syndrome.

Hypoplastic left heart syndrome (HLHS) is one of the most severe congenital heart malformations, characterized by underdevelopment of the structures in the left heart-aorta complex. The majority of cases are sporadic. Although multiple genetic loci have been tentatively implicated in HLHS, no gene or pathway seems to be specifically associated with the disease. To elucidate the genetic basis of HLHS, we analyzed 53 well-characterized patients with isolated HLHS using an integrated genomic approach that combined DNA sequencing of five candidate genes (NKX2-5, NOTCH1, HAND1, FOXC2 and FOXL1) and genome-wide screening by high-resolution array comparative genomic hybridization. In 30 patients, we identified two novel de novo mutations in NOTCH1, 23 rare patients inherited gene variants in NOTCH1, FOXC2 and FOXL1, and 33 rare patients mostly inherited copy-number variants. Some of the identified variations coexisted in the same patient. The biological significance of such rare variations is unknown, but our findings strengthen the role of NOTCH pathway in cardiac valve development, indicating that HLHS is, at least in part, a 'valve' disease. This is the first report of de novo mutations associated with isolated HLHS. Moreover, the coexistence of multiple rare variants suggests in some cases a cumulative effect, as shown for other complex disease.

Management of the univentricular connection: are we improving?

OBJECTIVE: To assess the impact of the bidirectional cavopulmonary shunt, total cavopulmonary connection, and baffle fenestration on outcome of the Fontan operation in our unit. METHOD: We reviewed 123 bidirectional cavopulmonary shunts and 264 Fontan operations performed from 1980 to 1995. Analysis of pulmonary artery size (right and left main and lower lobe branches) before and after bidirectional cavopulmonary shunt was performed. Outcome of the Fontan operation was analysed in various time periods to assess the effect of prior bidirectional cavopulmonary shunt, use of the lateral tunnel, and fenestration. RESULTS: Operative risk for the bidirectional cavopulmonary shunt was 4% (CI = 2-10%) with a survival of 89% (CI = 83-95%) at 36 months. Probability of conversion to Fontan operation at 36 months was 49% (CI = 38-61%). Pulmonary artery size (Nakata and lower lobe indices) fell after bidirectional cavopulmonary shunt (P = 0.0006). Fontan risk dropped from 8.5% (1980-1987) to 1.8% (1988-1995) (P = 0.02), coinciding with the use of the bidirectional cavopulmonary shunt. There was no further risk reduction after introduction of the lateral tunnel and baffle fenestration, although these comparisons are limited by relatively small numbers. Duration of hospital stay related to pleural effusions was lowest for patients with a fenestrated lateral tunnel operation (P < 0.05). CONCLUSION: The bidirectional cavopulmonary shunt is a suboptimal stimulus for pulmonary artery enlargement, but may reduce the risk of Fontan operation in selected children. Fenestrated lateral tunnel operations have reduced the duration of postoperative pleural effusions.

Avoiding hypoxemia during unifocalization.

An 11-month-old child underwent unifocalization of the major aortopulmonary collateral arteries, but did not tolerate occlusion of both vessels simultaneously. Using a Y-shaped homograft tube, we translocated the vessels sequentially and avoided severe hypoxemia.

Taussig-Bing anomaly and arterial switch: aortic arch obstruction does not influence outcome.

OBJECTIVE: Aortic arch obstruction is a commonly associated problem in the Taussig-Bing anomaly. Between 1983 and 1995, 28 consecutive patients with Taussig-Bing anomaly underwent arterial switch operation with baffling of the left ventricle to neoaorta. Group A: 11/28 had associated aortic arch obstruction. Group B: 17/28 had isolated Taussig-Bing anomaly. We assessed whether the coexistence of subpulmonary ventricular septal defect and aortic arch obstruction pose an incremental risk factor. PATIENTS AND RESULTS: Group A: Mean age and weight were 1.4+/-1.3 months and 3.5+/-0.4 kg. The aortic arch obstruction included: hypoplasia (5/11), interruption (4/11) and discrete coarctation (2/11). Seven patients had a one-stage correction, and four had initial arch repair followed by arterial switch operation. There were no hospital deaths (CL 0-28%). Over a follow-up of 638 patient-months (mean 64+/-39), there have been no late deaths, and all patients are in New York Heart Association class 1. There have been three cases of recurrent aortic arch obstruction (two requiring reoperation, and one requiring balloon dilation). One patient has been reoperated upon for right ventricular outflow tract obstruction. The actuarial survival and freedom from reoperation rates at 6 years were 100% (CL = 66-100%) and 72.9% (CL=38-92%) respectively. Group B: Mean age and weight were 5.9+/-8.4 months and 5+/-2.1 kg. All patients had a one-stage operation. There were two early deaths (11.8%, CL = 1-36%) and one late death over a follow-up of 678 patient-months (mean 52+/-31). All survivors are in New York Heart Association class 1 and there have been no reoperations. The actuarial survival and freedom from reoperation rates at 6 years were 81% (CL = 56-93%) and 100% (CL = 76-100%) respectively. CONCLUSIONS: 1. Aortic arch obstruction has not adversely affected early or late survival (P>.05) or late functional class. 2. Patients with Taussig-Bing anomaly and aortic arch obstruction may have a higher reoperation rate than those with normal arch anatomy. 3. Taussing-Bing anomaly, with or without aortic arch obstruction, can be repaired with arterial switch operation during the neonatal period with good outcome.

Anatomic repair of transposition of great arteries with ventricular septal defect and aortic arch obstruction. One-stage versus two-stage procedure.

Between September 1, 1982, and March 1, 1992, 40 patients underwent anatomic repair of transposition of the great arteries, ventricular septal defect, and aortic arch obstruction. In group I, 26 patients (65%) underwent repair in a two-stage procedure, phases A and B. Phase A included repair of the aortic arch obstruction with (16 patients) or without (10 patients) pulmonary artery banding through a left thoracotomy (mean age 18.7 +/- 23.4 days). There were three deaths and three reoperations. Phase B included an arterial switch operation with closure of the ventricular septal defect (mean age 95.5 +/- 122 days). There were five early deaths and two late deaths. Eight patients required reoperation. Mean delay between phase A and phase B was 77.5 +/- 109 days. In group I, there were eight early and two late deaths, and 11 patients required reoperation. The mean stay in the intensive care unit was 24.7 +/- 20 days. Mean follow-up of 59.6 +/- 21.4 months was completed in all survivors. All but one were in New York Heart Association class I without medication. Actuarial survival rate and rate of freedom from reoperation at 5 years were 57.5% and 49.9%, respectively. In group II, 14 patients (35%) had a one-stage procedure through midsternotomy: an arterial switch operation with closure of the ventricular septal defect and repair of the aortic arch obstruction (mean age 10.2 +/- 5.5 days). There were two early deaths (14.2%) and one late death after reoperation for overlooked multiple ventricular septal defects. Two patients required reoperation. The mean stay in the intensive care unit was 11.7 +/- 2.5 days. Mean follow-up of 22.4 +/- 16.7 months was achieved in all survivors. They were all in New York Heart Association class I without medication. Actuarial survival rate and rate of freedom from reoperation at 3 years were 78.5% and 81.5%, respectively. The one-stage procedure allowed complete repair in neonates without the need for multiple operations. We believe that it may decrease early mortality rates (14.2% versus 30.7%), reduce the reoperation rate and cumulative stay in the intensive care unit (11.7 days versus 24.7 days, p = Not significant), and significantly decrease the overall rate of morbidity (p < 0.01). However, requirements for surgical intervention with a one-stage or a two-stage procedure must include accurate assessments of intracardiac and aortic arch anatomy.

Neonatal anatomic repair of transposition of the great arteries and ventricular septal defect.

From January 1985 to March 1992, 64 consecutive neonates with transposition of the great arteries (TGA) and ventricular septal defect (VSD) underwent an arterial switch operation and VSD closure. The mean age at operation was 18.5 +/- 12 days and the mean weight was 3.3 kg. Seventeen patients had an associated aortic coarctation, of whom 15 underwent single-stage repair through median sternotomy. Coronary artery distribution was: type A: 45 patients; type B: 2; type D: 11 and type E: 6 patients. The location of the VSD was perimembranous in 42 patients, trabecular in 13, infundibular in 5, and 4 presented with the Taussig Bing heart anomaly. The hospital mortality was 9.3% (n = 6). There were four late deaths (one TGA-VSD and three TGA-VSD and coarctation). Nine patients required reoperation. The mean follow-up of all survivors was 36 +/- 19 months. They were in NYHA class I without medication. Six patients developed mild-to-moderate aortic insufficiency. The actuarial survival and freedom from reoperation at 5 years were 81.06% and 84.6%, respectively. We conclude that neonatal anatomic repair of TGA and VSD offers good medium-term results and avoids iterative operations.