Remarkable case of uncorrected type IC tricuspid atresia with adaptive pulmonary trunk dilatation to allow prolonged survival: Case report and CT fly-through

Abstract

A remarkable case of a surgically uncorrected Type IC (no great artery transposition, no pulmonary stenosis) tricuspid atresia surviving to adulthood is presented. This is a case of an adult female of 30 years of age with an atretic tricuspid valve, an atrial septal defect, a large ventricular septal defect, and a dilated pulmonary trunk. Surgical correction was never conducted on this heart with a significant congenital cardiac defect, and yet the individual survived into a fourth decade. Without surgical correction, survival to adulthood in tricuspid atresia is exceedingly rare. Survival depends on a high degree of ventricular shunting with limited pulmonary outflow obstruction. The resistance of this obstruction must be both low enough to maintain increased pulmonary blood flow and high enough to prevent systemic-level pressures upon the pulmonary vasculature. The unique finding of a significantly dilated pulmonary trunk is described, which presumably allowed this individual to survive to adulthood. This complex physiology is described and augmented with high-resolution images of this cardiac specimen. These were made possible by the application of a plastination process prior to obtaining high-resolution multi-slice computed tomography imaging studies. The result is a study comprised of multiplanar and three-dimensional data detailing the anatomic features of the specimen, which were then used to create reconstructions of the specimen for visualization of the anatomy. An understanding of the development and morphology of tricuspid atresia is essential for successful surgical correction in new patients with this congenital malformation. Keywords: Tricuspid atresia, Pulmonary blood flow, Pulmonary hypertension, Plastination, CT