Obstructed pulmonary venous drainage with total anomalous pulmonary venous connection to the coronary sinus.

Obstructed pulmonary venous drainage is generally considered extremely rare with total anomalous pulmonary venous connection (TAPVC) to the coronary sinus (CS). A retrospective review of 27 operated patients with TAPVC to CS revealed 6 cases of obstruction (22%). Two of 6 patients who died early had evidence of obstruction at the pulmonary vein confluence at autopsy. Among the 21 hospital survivors, obstruction proximal to the point of CS unroofing developed in 4 (19%), necessitating reoperation and resulting in death in 3. One other patient died late. Mean follow-up of the 17 long-term survivors, who are generally doing well, is 85 months (range 2 to 212). There have been no cases of late obstruction at the site of unroofing among 10 patients who underwent the fenestration procedure suggested by Van Praagh. The incidence of early bradyarrhythmias (60%) does not appear to be decreased by this procedure. Review of 13 autopsy specimens suggests that if the right and left pulmonary veins did not drain directly to the CS but converged to form a short common vertical vein (4 cases), obstruction was likely. When pulmonary artery pressure approaches systemic levels preoperatively, careful echocardiographic and intraoperative assessment of the junction of the pulmonary vein confluence with the CS should be made. If there is evidence of obstruction, consideration should be given to anastomosing the horizontal right and left pulmonary veins directly to the left atrium rather than performing a simple unroofing procedure.