Mixed total anomalous pulmonary venous connection: anatomic variations, surgical approach, techniques, and results.

Objective: The purpose of this study was to identify the morphologic characteristics and other risk factors that may predispose patients with mixed totally anomalous pulmonary venous connection to continuing high mortality after surgery.
Methods: Fifty-seven consecutive patients aged 15 days to 18 years (median, 6 months) underwent rechanneling of mixed totally anomalous pulmonary venous connection. Twenty-three patients had "2+2" pattern (I category), 29 had "3+1" pattern (II category), and 5 patients had pulmonary venous connections of different combinations (III category). Obstructive patterns involving one or more pulmonary veins were present in 19 (33.3%) patients.
Results: Operative and late mortality rates were 19.3% and 4.3%, respectively. At a mean follow-up of 63.26 +/- 58.47 months, actuarial survival was 86.9% +/- 0.07% in category I, 86.2% +/- 0.06% in category II, and 20.0% +/- 0.18% in category III (log-rank, P = .001), respectively. At their last follow-up, all survivors (n = 43) had a Ross clinical heart failure score of 0 to 2.
Conclusions: Patients with a "2+2" pattern of mixed totally anomalous pulmonary venous connection constitute the safe anatomic category for rechanneling, followed by the "3+1" variety. Cross-sectional echocardiography and/or computed tomographic angiography are mandatory to provide necessary diagnostic information and define the anatomy. Patients aged 2 months or younger, obstructive totally anomalous pulmonary venous connection, and perioperative pulmonary hypertensive crises were significant risk factors for death by logistic regression analysis. The risk of death was 5.85 times higher (95% confidence interval: 1.46-35.68; P = .02) in patients with category III of mixed TAPVC. The precise technique adopted in an individual patient depends on the pattern of anatomic drainage, and an individualized surgical approach is recommended.