Abraham Rothman

The purpose of this work was to develop and characterize an aortopulmonary shunt model of chronic pulmonary hypertension in swine and provide sequential hemodynamic, angiographic, and histologic data by using an experimental endoarterial biopsy catheter. Nine Yucatan female microswine (Sus scrofa domestica) underwent surgical anastomosis of the left pulmonary artery to the descending aorta. Sequential hemodynamic, angiographic, and pulmonary vascular samples were obtained. Six pigs (mean weight, 22.4±5.3 kg; mean age, 7.3±2.7 mo at surgery) survived long-term (6 mo) and consistently developed marked pulmonary arterial hypertension. Angiography showed characteristic central pulmonary arterial enlargement and peripheral tortuosity and pruning. The biopsy catheter was safe and effective in obtaining pulmonary endoarterial samples for histologic studies, which showed neointimal and medial changes. Autopsy confirmed severe pulmonary vascular changes, including concentric obstructive neointimal and plexiform-like lesions. This swine model showed hemodynamic, angiographic, and histologic characteristics of chronic pulmonary arterial hypertension that mimicked the arterial pulmonary hypertension of systemic-to-pulmonary arterial shunts in humans. Experimental data obtained using this and other models and application of an in vivo endoarterial biopsy technique may aid in understanding mechanisms and developing therapies for experimental and human pulmonary arterial hypertension.

Newborns with obstructed infradiaphragmatic total anomalous pulmonary venous return (TAPVR) are often clinically unstable. Temporary relief of the pulmonary venous obstruction may improve their clinical status before surgical repair. Three neonates (two premature and one full-term) with obstructed infradiaphragmatic TAPVR at the ductus venosus (DV) underwent stenting of the DV by way of an umbilical venous approach. Their clinical condition stabilized, thus allowing subsequent elective surgical repair.

An 86 year-old male presented with progressive shortness of breath and a murmur. Six years earlier, he had undergone mitral valve surgery. An echocardiogram revealed a significant left ventricular-to-right atrial connection (Gerbode defect). The defect was closed percutaneously using an Amplatzer Septal Occluder device. After the procedure, the patient developed transient hemolysis and renal dysfunction. A year later, there was no residual flow on echocardiography and the patient reported marked improvement in exercise tolerance.

An 18-year-old boy who underwent coil occlusion of a patent ductus arteriosus and stenting for aortic coarctation at 13 years of age had evidence of re-stenosis. Cardiac catheterization and angiography showed a 25-mmHg gradient across the stent and a large aneurysm originating at midstent level. The aneurysm measured 2 cm in width and 4.3 cm in length. At a subsequent catheterization procedure, two 4.5-cm-long overlapping Cheatham platinum covered stents were implanted, completely excluding the aneurysm. Computed tomographic (CT) angiography 2 years later showed no evidence of endoleak or re-stenosis.

A 6-year-old girl with heterotaxy and a functional single ventricle had persistent cyanosis 4 years after a fenestrated Fontan procedure. Cardiac catheterization revealed a large venous fistula from a left-sided hepatic vein to the coronary sinus, resulting in desaturation. The anomalous vein was occluded with an Amplatzer vascular plug.

A variety of techniques have been utilized to close Fontan fenestrations. Among 20 patients who underwent a cardiac catheterization for fenestration closure, 3 patients had residual native atrial septum, forming an additional intermediate chamber on the pulmonary venous side of the fenestration. Three different methods were used to close these fenestrations.