Ex-utero intrapartum treatment as a novel bridging strategy to surgery in hypoplastic left heart syndrome with intact atrial septum—cross-circulation revisited

Interatrial Septum Stenting for Hypoplastic Left Heart Syndrome in Ex Utero Intrapartum Therapy

Patients with hypoplastic left heart syndrome (HLHS) with intact atrial septum have an increased mortality rate. This presentation occurs in 6% to 10% of cases. We present a patient with fetal diagnosis of HLHS with restrictive atrial septum. We performed a cesarean section at 37 weeks of gestation, and under ex utero intrapartum treatment proceeded with a median sternotomy and transatrial stenting for left atrial decompression due to findings of intact atrial septum on the fetal echocardiogram performed during the procedure. Subsequently, the patient underwent hybrid stage I palliation followed by a comprehensive stage II procedure at five months of age, but unfortunately died from postoperative complications.

Evolving Approach in Hypoplastic Left Heart Syndrome With Restrictive and Intact Septum

Background: Hypoplastic left heart syndrome (HLHS) with either intact atrial septum (IS) or highly restrictive interatrial communication (HRIC) is associated with poor survival. Immediate postpartum access to cardiac therapy and timely left atrial decompression (LAD) are paramount to a successful outcome. We describe herein our evolving approach to LAD and report interstage and longer-term results. Methods: We retrospectively identified neonates with HLHS IS/HRIC requiring LAD between 2005 and 2019. All babies had prenatal/postnatal echocardiography. Our LAD strategy evolved over time from attempt at transcatheter balloon atrial septostomy (BAS) to surgical septectomy with inflow occlusion, to hybrid trans-atrial stent implantation. Results: Twelve neonates required LAD at a median time of 14 (0.5-31) hours after birth. Five patients underwent BAS that proved successful in 2 cases. Of the 3 unsuccessful cases, 2 required extra-corporeal membrane oxygenation (ECMO) support and died subsequently; one underwent hybrid trans-atrial stent implantation. Of the remaining 7 patients, 3 underwent surgical septectomy with inflow-occlusion and 4 underwent hybrid trans-atrial stent implantations. Overall, 8 patients survived LAD and reached Norwood palliation. Three of the 8 required ECMO postoperatively. There was no hospital mortality after Norwood stage 1 palliation and interstage survival was 100%. Six patients successfully underwent Glenn shunt (superior cavopulmonary anastomosis) and 5 have completed total cavopulmonary connection. Conclusions: Our experience suggests that prompt postnatal LAD can be safely achieved with careful multidisciplinary planning and accurate antenatal diagnosis. In our hands, hybrid trans-atrial septal stent insertion appears to be a safe approach which combines the versatility of transcatheter techniques together with the effectiveness of surgical control.

Toward Eliminating Perinatal Comfort Care for Prenatally Diagnosed Severe Congenital Heart Defects: A Vision

Over the past 40 years, the medical and surgical management of congenital heart disease has advanced considerably. However, substantial room for improvement remains for certain lesions that have high rates of morbidity and mortality. Although most congenital cardiac conditions are well tolerated during fetal development, certain abnormalities progress in severity over the course of gestation and impair the development of other organs, such as the lungs or airways. It follows that intervention during gestation could potentially slow or reverse elements of disease progression and improve prognosis for certain congenital heart defects. In this review, we detail specific congenital cardiac lesions that may benefit from fetal intervention, some of which already have documented improved outcomes with fetal interventions, and the state-of-the-science in each of these areas. This review includes the most relevant studies from a PubMed database search from 1970 to the present using key words such as fetal cardiac, fetal intervention, fetal surgery, and EXIT procedure. Fetal intervention in congenital cardiac surgery is an exciting frontier that promises further improvement in congenital heart disease outcomes. When fetuses who can benefit from fetal intervention are identified and appropriately referred to centers of excellence in this area, patient care will improve.

Innovative 2-Step Management Strategy Utilizing EXIT Procedure for a Fetus With Hypoplastic Left Heart Syndrome and Intact Atrial Septum

Hypoplastic left heart syndrome (HLHS) with intact atrial septum (HLHS-IAS) carries a high risk of mortality and affects about 6% of all patients with HLHS. Fetal interventions, postnatal transcatheter interventions, and postnatal surgical resection have all been used, but the mortality risk continues to be high in this subgroup of patients. We describe a novel, sequential approach to manage HLHS-IAS and progressive fetal hydrops. A 28-year-old, gravida 4 para 2 mother was referred to Mayo Clinic for fetal HLHS. Fetal echocardiography at 28 weeks of gestation demonstrated HLHS-IAS with progressive fetal hydrops. The atrial septum was thick and muscular with no interatrial communication. Ultrasound-guided fetal atrial septostomy was performed with successful creation of a small atrial communication. However, fetal echocardiogram at 33 weeks of gestation showed recurrence of a pleural effusion and restriction of the atrial septum. We proceeded with an Ex uteroIntrapartum Treatment (EXIT) delivery and open atrial septectomy. This was performed successfully, and the infant was stabilized in the intensive care unit. The infant required venoarterial extracorporeal membrane oxygenator support on day of life 1. The patient later developed hemorrhagic complications, leading to his demise on day of life 9. This is the first reported case of an EXIT procedure and open atrial septectomy performed without cardiopulmonary bypass for an open-heart operation and provides a promising alternative strategy for the management of HLHS-IAS in select cases.

Extracorporeal membrane oxygenation in congenital heart disease

This review article will discuss the indications for and outcomes of neonates with congenital heart disease who receive extracorporeal membrane oxygenation (ECMO) support. Most commonly, ECMO is used as a perioperative bridge to recovery or temporary support for those after cardiac arrest or near arrest in patients with congenital or acquired heart disease. What had historically been considered a contraindication to ECMO, is evolving and more of the sickest and most complicated babies are cared for on ECMO. Given that, it is imperative for aggressive survellience for long-term morbidity in survivors, particularly neurodevelopmental outcomes.

Surgical outcome of hypoplastic left heart syndrome with intact atrial septum

Background

The surgical outcomes of hypoplastic left heart syndrome with intact atrial septum remains very poor in spite of the introduction of prenatal diagnosis before the Norwood operation. The hybrid operation consisting of bilateral pulmonary artery banding and balloon atrioseptectomy is one of the treatment strategies to potentially improve this patient population, however, the long-term outcomes are unknown.

Methods

Six consecutive patients with hypoplastic left heart syndrome with intact atrial septum, who underwent the hybrid operation between October 2006 and July 2014, were retrospectively reviewed. Hypoplastic left heart syndrome with highly restrictive atrial communication was excluded.

Results

Three patients died after the hybrid operation, due to sepsis, cerebral bleeding, and heart failure. Three patients underwent the modified Norwood operation. One of these died due to severe hypoxia while awaiting the bidirectional Glenn operation. The others underwent a bidirectional Glenn operation and subsequent Fontan completion but died due to lung dysfunction and sudden hemoptysis.

Conclusions

The hybrid operation for hypoplastic left heart syndrome with intact atrial septum may have improved the neonatal outcome and Fontan completion rate in this extremely high-risk group of patients, but the long-term outcome remains dismal. Considering the late mortality related to pulmonary complications, aggressive fetal intervention to create a nonrestrictive atrial septal communication to promote normal development of the pulmonary vessels may be the last resort to improve the long-term outcome.