SAN DIEGO — Fetal intervention appears to boost midterm survival of children with hypoplastic left heart syndrome and an intact or highly restricted atrial septum, Dr. Vladimiro L. Vida said at the annual meeting of the Society of Thoracic Surgeons.
Nine of 14 such patients at Children's Hospital of Boston who underwent fetal intervention were alive at 6 months, compared with 6 of 16 in whom surgeons waited until after birth to perform urgent atrial decompression. That translates to a 6-month survival rate of 64% in the fetal intervention group compared with 37% in patients who received what was until now considered state-of-the-art care starting immediately postnatally, noted Dr. Vida, a pediatric cardiac surgery fellow at the hospital.
Fetal intervention consisted of balloon atrial septectomy or aortic balloon dilation. The purposes were to eliminate the immediate postnatal cyanosis that accompanies this form of congenital heart disease, achieve circulatory stability, and promote normal vascular and parenchymal development. The hypothesis was that this would improve both short- and long-term outcome in patients with this otherwise very-poor-prognosis abnormality, the physician explained.
Based upon the favorable experience to date, Dr. Vida recommended encouraging referral for fetal intervention in all patients identified prenatally as having hypoplastic left heart syndrome (HLHS) with an intact atrial septum by fetal echocardiography, or with poor flow or reversal of flow in the pulmonary vein.
Outcomes in HLHS have improved in the last decade, but the subgroup with an intact or highly restrictive atrial septum has lagged behind. Fortunately, it is not a common defect. The 30 affected patients Dr. Vida reported on were among 230 consecutive HLHS patients managed at Children's Hospital of Boston in a period beginning in January 2001. Twenty-five of the 30 were diagnosed prenatally as having an intact atrial septum, so surgeons were standing by to perform transcatheter atrial septectomy to create an interatrial communication immediately after birth in most of those who didn't undergo fetal intervention.
Surgical palliation was performed at a median age of 4 days. A modified Blalock-Taussig shunt was utilized for this purpose in 26 of 30 patients. Delayed sternal closure was required in 24. Operative mortality was 30%, and five additional patients died in the interstage period. Both operative and interstage mortality were lower in patients who had undergone fetal intervention.
Five patients required early revision of their Blalock-Taussig shunts—four because of poor circulation and one because of shunt thrombosis.
Early shunt revision, need for postoperative support using extracorporeal membrane oxygenation, a longer cardiopulmonary bypass time, and the presence of pulmonary venous pathology were associated with increased risk of in-hospital mortality, Dr. Vida continued.
Discussant Dr. Jeffrey P. Jacobs hailed Dr. Vida's report as “truly groundbreaking.” Soon-to-be-published data provided to him by colleagues at Children's Hospital of Philadelphia underscore the extremely high risk of HLHS with an intact or highly restrictive atrial septum when managed conventionally—that is, starting postnatally, added Dr. Jacobs of the University of South Florida, Tampa.
Thirty-day survival of patients in the Philadelphia series was just 38%. Moreover, there was no difference in outcome between those diagnosed pre- and postnatally. Survival wasn't improved by a strategy involving early aggressive postnatal intervention based upon prenatal diagnosis.
Outcomes in HLHS have improved, but the subgroup with an intact or highly restrictive atrial septum has lagged behind. DR. VIDA
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