2.2 Surgical techniques
The first patient underwent staged repair, with a thoracotomy approach for coarctation repair without PA banding, followed by the ASO performed via a median sternotomy approach later. All the remaining TBV patients in our study, including the patients who required aortic arch reconstruction as well, were treated via a single incision through a median sternotomy using isolated cerebral perfusion.
Standard bypass was established with an arterial cannula placed at the base of the innominate artery, bicaval cannulation and moderate hypothermia was used for all patients in our study. The autologous pericardium was harvested and kept in saline. The core temperature was decreased to 28°C during dissection, and near-infrared spectroscopy was used to monitor all patients. In cases in which coarctation or aortic arch reconstruction was required, the aortic cannula was advanced into the innominate artery, and antegrade cerebral perfusion was performed with the surgical technique for aortic arch reconstruction, as previously described (11). The closed technique for coronary transfer was used in all patients (12). We combined the trapdoor technique for left coronary button reimplantation and a simple incision for the right coronary button to minimize dilatation of the sinotubular junction and the sinus of Valsalva. The Lecompte maneuver was applied in all cases, irrespective of the relationship of the great arteries. The majority of patients underwent VSD closure through the right atrium using interrupted pledget sutures, except for 1 patient, who required an approach through the neopulmonary valve (neo-PV). For the upper part of the VSD, as the most difficult part of VSD closure through right atrial, a needle holder is used to shape the suture needle into a “fishhook” shape, and a forceps was used to temporary push down the outside of the pulmonary annulus. The surgeon can now easily see the superior aspect of the VSD, and close it through the tricuspid valve. The neo-PA was reconstructed using a fresh autologous pericardial patch, with particular care taken to trim the height and width of the patch to avoid torsion of the pulmonary bifurcation, which we considered to be the main cause of PA branch stenosis after the operation. We took meticulous care to make sure that the height of the neo-PA patch was equal to the height of the remaining anterior wall of the neo-PA, the width of the patch was not excessive and the diameter of the neo-PA after reconstruction was equal to the diameter of the PA bifurcation.
Before releasing the aortic cross clamp, the RVOT was always examined through the neo-PV. In cases where SPT were prominent and protruded into the RVOT, they were excised or divided totally from the RVOT up to the apex of the right ventricle, if possible, to avoid RVOTO. The key point to help surgeons realizes these structures and avoid resecting too much out of the heart is that these structures lie in an abnormal position, making connections adherent between the posterior ventricular septum at the infundibulum area superiorly, continuous with the tricuspid annulus at the area of inlet component of the right ventricle inferiorly, and the free wall of the right ventricle, which is not seen in the normal heart (Figure 1). These anomalous structures were described by Dr. Robert Anderson, which is also described as the right ventricular trabeculations arise from the anterior margin of the septomarginal trabeculation (page 41, Anatomy of the cardiac chambers) (13). These muscle bands are customary to the TBV lesion, are easily identified by RVOT inspection after ASO + VSD closure. Additionally, when the neo-PV annulus appeared hypoplastic, an approach through the tricuspid valve could be used to divide the SPTs.
The patent foramen ovale was stretched or a small atrial septal defect was left open to help decompress the right ventricle and maintain the cardiac output of the patient during intensive care management. Distal anastomosis of the neo-PA was completed after removal of the Ao cross clamp. In cases where the great arteries were side-by-side or the aorta arose from the anterior and right sides of the pulmonary system, the neo-PA was then shifted to the right PA to avoid coronary compression or torsion of the distal PA. The remaining defect in the PA bifurcation was closed by an autologous pericardial patch to avoid left PA stenosis.
In patients who required reoperation due to RVOTO, the procedure was performed through the neo-PA and the tricuspid valve, and the SPT remnants were resected, with the RV pressure being directly measured in combination with transesophageal echocardiography to confirm freedom from RVOTO. No transannular patches were required in our series for reoperation because we did not identify any cases of significant hypoplasticity of the neo-PV annulus during follow-up.