Separation of neointima from Dacron graft causing obstruction. Case following Fontan procedure for tricuspid atresia

A nine-year-old patient with tricuspid atresia and normally related great vessels underwent a Fontan procedure, in which a porcine valved Dacron conduit was interposed between the right atrium and pulmonary trunk. After death, 6 months postoperatively, pathological examination revealed a thick layer of neointima (peel) lining the conduit. The peel was thicker in the segment of the conduit proximal to the valve, where it measured up to 4.5 mm in thickness. Proximal to the valve, the peel had separated from the wall of the graft and a hematoma had developed between the separated peel and graft. The result was reduction in the caliber of the conduit to about half the original. The patient's final illness was complicated, being associated with acute pancreatitis. Reduction in the caliber of the graft may have contributed to the death.