left atrium, in a manner similar to superior sinus venosus atrial septal defects with partial anomalous pulmonary venous connection In supracardiac and infracardiac TAPVC repair, the pulmonary venous confluence can be accessed from the right or the left side In the left-sided approach, the heart can be retracted anteriorly and rightward to expose the pulmonary venous confluence Corresponding incisions are made in the pulmonary venous confluence and the left atrium and an anastomosis is constructed between the divided structures (Video 28.8) Care must be taken to ensure that the rightward retraction of the heart does not result in distortion of the anastomosis when the heart is returned to its anatomic position Alternatively, in the right-sided approach, the pulmonary vein confluence is accessed through the right atrium, through the atrial septum, and through an incision in the posterior wall of the left atrium The pulmonary vein confluence is incised and anastomosed to the left atrium The divided atrial septum is often closed with a pericardial patch, which also serves to enlarge the overall size of the left atrium Mixed TAPVC repair is dictated by the underlying anatomy, with the most common anatomy being where one vein remains connected to the systemic venous circulation while the other three veins drain into a posterior confluence With this arrangement, the confluence is anastomosed to the posterior left atrium and the solitary vein is reimplanted or incorporated into larger confluence anastomosis using a sutureless technique (described later) In some cases a single pulmonary vein can remain connected to the systemic venous circulation, resulting in a small residual left-to-right shunt that does not affect the overall hemodynamics Sutureless Technique The sutureless technique was introduced in 1996 by two groups87,92 and was developed to address PVS, which arose after repair of TAPVC (postrepair PVS) Initial early and midterm results suggested encouraging freedom from recurrent stenosis.93–98 The use of the sutureless technique has been extended as a primary repair technique for TAPVC and as a prophylactic strategy to minimize postrepair PVS; midterm single-institution cohorts have demonstrated noninferiority of this technique when compared with conventional repair The sutureless technique utilizes resection of obstructed pulmonary veins and direct suturing of the left atrium to the pericardium around the divided pulmonary vein confluence, avoiding direct suturing of the left atrium to the pulmonary veins The main theoretical advantages derived from the sutureless technique include maximizing the confluence size, minimizing distortion, avoiding suture-related trauma to the incised pulmonary vein tissue, avoiding circulatory arrest, and diminished geometric complexity in comparison to conventional repairs Encouraging midterm results have been seen in small series of high-risk groups such as children with infracardiac and mixed TAPVC, a small confluence, or preoperative pulmonary vein obstruction.88–90,99 A large retrospective study has found that the sutureless technique is associated with a lower rate of postrepair PVS than conventional repair.100 Although evidence supports the use of sutureless techniques, prospective trials have not been undertaken owing to prohibitive sample size requirements Vertical Vein The vertical vein is often ligated at the time of surgery Some surgeons elect to leave it open as a mechanism to decompress elevated left atrial pressures in patients in whom the left heart has difficulty tolerating an acute increase in pulmonary venous return after surgery In this respect, the patent vertical vein has the same physiologic effect as an atrial septal defect, and this can be beneficial in the management of postoperative pulmonary hypertension.58,61,100 After repair, flow through this high-resistance pathway is thought to be negligible,100–104 although a follow-up study on these patients suggests that this vein often remains patent.102 Intraoperatively, the surgeon can guide decision making by measuring the left atrial and systemic arterial pressures after the patient is taken off bypass If snaring of the vertical vein is achieved without a rise in left atrial pressure and a fall in systemic pressure, ligation of the vein is performed.103–105 Case reports have demonstrated delayed closure of the vertical vein with percutaneous devices for those children who develop significant leftto-right shunts postoperatively.106–108 Results of Surgery The late results of surgical repair of total anomalous pulmonary venous connection are generally excellent.99,109 The hazard function for death becomes similar to that of the general population within about 24 months of operation.110 Nonetheless, late pulmonary venous obstruction (postrepair PVS) occurred in about 10% of all large surgical series, and this has remained relatively constant over the last 30 years This serious complication is poorly understood and can occur in patients with and without obstruction prior to surgery.111 Factors associated with poor surgical outcomes include infracardiac or mixed drainage, repairs made at a younger age, and complex congenital cardiac lesions (i.e., single-ventricle physiology).86,91 Importantly, postrepair PVS and preoperative pulmonary venous obstruction are also associated with increased risk of death.86,89,90,99 Patients with a small pulmonary venous confluence and residual gradients in the pulmonary veins following repair are at risk of developing postrepair PVS.86 Postrepair Pulmonary Venous Stenosis Postrepair PVS typically occurs within the first year following repair, with many cases presenting within 4 to 6 weeks following the initial repair The clinical presentation may be silent until the time of significant stenosis or can be picked up on routine surveillance imaging The early development of postrepair PVS is associated with poor outcomes.86,89,90 Precipitants for the development of postrepair PVS are thought to arise within two broad categories The first category is comprised of children who develop anastomotic stricture due to technical imperfections and those with inadequate resection or failure to create a large anastomosis, resulting in residual gradients In this group the sutureless repair technique may offer the most benefit, as it neutralizes complex geometry of the pulmonary confluence, minimizes anatomic distortion, and maximizes anastomotic size with the creation of a neoatrium In a small subset of children, disease progression may result in the absence of associated surgical risk factors and other precipitants may be active, including abnormal pulmonary vein development or genetic or environmental triggers, which may influence the subsequent development of postrepair PVS.80,112 Surveillance for Postrepair Pulmonary Venous Stenosis As the majority of children who undergo TAPVC repair will not develop postrepair stenosis; screening by echocardiography is the standard and should be done within 4 to 6 weeks following repair The diagnosis is made by color-flow