Tetralogy of Fallot: Current surgical perspective

Abstract

Tetralogy of Fallot (TOF) is an important lesion for all pediatric and congenital heart surgeons. In designing the most appropriate operation for children with TOF, the postoperative physiology should be taken into account, both in the short and long term. The balance between pulmonary stenosis (PS) and pulmonary insufficiency (PI) may be critical for preservation of ventricular function. A unified repair strategy that limits both residual PS and PI is presented, along with supporting experimental evidence, a strategy for dealing with coronary anomalies, and comments regarding best timing of operation.

Keywords: Right ventricular function; residual pulmonary incompetence; residual right ventricular outflow obstruction.

Figure 1

Creation of a chronic porcine model of PI (upper frames) and combined PS/PI (lower frames), achieved with percutaneous delivery of transannular stents (with and without a PTFE diaphragm) into the RVOTO (from Kuehne et al, 2005, used by permission)

Figure 2

Representative right ventricular pressure-volume loop of a pig with combined pulmonary stenosis and insufficiency and a control animal (measured at rest) at 3 month follow-up. Emax, slope of end-diastolic pressure-volume relation. (from Kuehne et al, 2005, used by permission)

Figure 3

Comparison of the classical transventricular approach (left) and the transatrial-transpulmonary approach (right). In the latter strategy the RV incision is limited to what is required to relieve the RVOTO, with VSD closure and RVOT resection performed via the TV and PA

Figure 4

Resection of the parietal extension of the infundibular septum, using a trans tricuspid approach. A Hegar dilator has been passed from the PA into the RV to demonstrate the outlet

Figure 5

(A) Pulmonary cusp augmentation repair technique. A transannular incision has been created according to calibration of the RVOT diameter (see text). The incision divides the anterior pulmonary valve leaflet, although the exact location will vary with the valve orientation and morphology. (B) Pulmonary cusp augmentation repair technique. A triangular patch of glutaraldehyde-preserved autologous pericardium is sutured to the epicardial edge of the RVOT incision and to the divided edges of the valve leaflet. The leaflet dimensions are based on the caliber of a normal pulmonary valve diameter and should provide sufficient free edge diameter to ensure coaptation with the native valve remnant. (C) Pulmonary cusp augmentation repair technique. A second larger oval patch of the same material is sutured to the epicardial aspect of the RVOT incision and to the edges of the pulmonary arteriotomy, creating a sinus anterior to the reconstructed leaflet

Figure 6

(A) LAD from the RCA, (B) all coronaries arising from the right sinus. Both situations would be problematic for a transventricular repair, but both patients had successful transatrial-transpulmonary repairs

Figure 7

TOF with RCA arising from LAD and crossing the RVOT. A transatrial-transpulmonary repair has been performes with a transannular patch stopping short of the anomalous coronary

Figure 8

Current protocol for timing of repair for neonates and infants with TOF. In practice, most patients will undergo elective repair by 3-4 months of age, or sooner if indicated clinically. The shunt strategy is reserved for selected cases with unfavorable anatomic features or compromised clinical condition (see text)