Surgical Management of Symptomatic Neonates with Tetralogy of Fallot

About 10% of neonates born with tetralogy of Fallot (TOF) become symptomatic and require urgent intervention. The two choices are early primary surgical repair (EPSR), in which the ventricular septal defect is closed and the right ventricular (RV) outflow obstruction is relieved, and a two-staged palliative (SP) approach, in which an interval shunt is used to secure a reliable source of pulmonary blood until the infant is larger and better able to withstand surgery. However, the ideal approach remains controversial.

“There are advantages and disadvantages to both approaches,” says Cleveland Clinic pediatric critical care specialist Mohammed Hamzah, MD. “EPSR for TOF ideally restores a normal cardiovascular anatomy and physiology, resolves the chronic cyanosis and promotes normal neurological development during a critical time of its rapid development in early infancy. It also may restore normal development of pulmonary vasculature and alveologensis in patients with diminished pulmonary perfusion,” he says.

“In symptomatic infants with hypercyanotic spells, a two-stage approach with an interval shunt ideally secures a reliable source of pulmonary blood flow. It also avoids potential organ damage from neonatal open-heart surgery and allows for time to attain somatic growth and organ maturity prior to the utilization of cardiopulmonary bypass in the second stage,” he says.

Taking a deep dive

In hopes of determining whether one strategy may be preferable, Dr. Hamzah and colleagues conducted a retrospective study of neonates ages 28 days and younger with TOF entered in the U.S. National Inpatient Sample (NIS) database between 2000 and 2018.

The patients were divided into two categories: asymptomatic infants and infants with severe symptoms necessitating immediate surgical intervention. They were further identified as having undergone EPSR, SP or no procedure.

The findings of this study were presented as an abstract at the Pediatric Academic Societies meeting in April 2021.

Similarities and differences

A total of 29,292 neonates with TOF were identified. Of these, 1,726 had undergone EPSR, 4,363 had undergone SP and 23,203 had no intervention as neonates.

Mortality rates in the EPSR and SP groups were found to be similar (8.0% vs. 7.4%).

Compared with EPSR, patients in the SP group had more comorbidities in the form of chromosomal anomalies (13.2% vs. 7.8%), prematurity (15.1% vs. 10.4%) and low body weight (15.4% vs.10.3%).

Compared with SP, EPSR patients had higher rates of ECMO utilization (4.6% vs. 3.5%), higher median length of stay (25 days vs. 19 days) and significantly higher median cost of hospitalization ($312,405 vs. $191,863).

The researchers also identified 15,946 patients with TOF who had undergone surgical repair after their first 28 days of life. These patients had significantly lower mortality than those who had undergone EPSR (1.5% vs. 8.0%).

“Several studies assessing the relationship between age of TOF surgical repair and RV hypertrophy remodeling showed that earlier repair was associated with a hastened course of RV remodeling and regression of RV hypertrophy, compared with late surgical repair,” says Dr. Hamzah. “If we include the cumulative morbidity and resource utilization associated with a two-staged repair, EPSR could be proven the better strategy in symptomatic neonates with TOF.”

The surgeon’s point of view

Hani Najm, MD, Chair of Pediatric and Congenital Heart Surgery at Cleveland Clinic, has performed several hundred EPSR cases. He agrees with the findings of this study.

“The goal should be to have a surviving patient with a good repair. This becomes center specific. If this can be achieved with SP, fine. Some centers defer to SP because they either have difficulty managing neonatal surgery or they have a bias for palliation he says. “Some centers have the option of doing both procedures and choose SP if it is reasonable. However, it is well known that palliative procedures requires repeated surgeries, continuation of cyanosis and possibly distortion of the pulmonary artery when the shunt is placed, necessitating more surgeries or stenting even after the final repair.”

In reality, says Dr. Najm, multiple factors must be considered when deciding on the better approach for a symptomatic neonate. Early and late outcome has to be in consideration. I believe every patient presents with a set of problems that the treating team should decide on the approach..

“Additionally, it’s very important to take into account factors not related to TOF itself, including low birth weight, brain hemorrhages and gastrointestinal tract anomalies, all of which are common in symptomatic neonates with TOF,” he says.