Pulmonary hypertension associated with portal hypertension in a child with Williams syndrome--a case report

Elastin insufficiency predisposes to elevated pulmonary circulatory pressures through changes in elastic artery structure

Elastin is a major structural component of large elastic arteries and a principal determinant of arterial biomechanical properties. Elastin loss-of-function mutations in humans have been linked to the autosomal-dominant disease supravalvular aortic stenosis, which is characterized by stenotic lesions in both the systemic and pulmonary circulations. To better understand how elastin insufficiency influences the pulmonary circulation, we evaluated pulmonary cardiovascular physiology in a unique set of transgenic and knockout mice with graded vascular elastin dosage (range 45-120% of wild type). The central pulmonary arteries of elastin-insufficient mice had smaller internal diameters (P < 0.0001), thinner walls (P = 0.002), and increased opening angles (P = 0.002) compared with wild-type controls. Pulmonary circulatory pressures, measured by right ventricular catheterization, were significantly elevated in elastin-insufficient mice (P < 0.0001) and showed an inverse correlation with elastin level. Although elastin-insufficient animals exhibited mild to moderate right ventricular hypertrophy (P = 0.0001) and intrapulmonary vascular remodeling, the changes were less than expected, given the high right ventricular pressures, and were attenuated compared with those seen in hypoxia-induced models of pulmonary arterial hypertension. The absence of extensive pathological cardiac remodeling at the high pressures in these animals suggests a developmental adaptation designed to maintain right-sided cardiac output in a vascular system with altered elastin content.

Portopulmonary hypertension in childhood presenting as sudden death

We present the case of a 9-year-old boy with portal hypertension who died suddenly and unexpectedly due to pulmonary hypertensive crisis during a routine endoscopic procedure. He had known portal hypertension with esophageal varices but had no preceding clinical symptoms suggestive of significant pulmonary hypertensive disease despite postmortem histological evidence of advanced pulmonary vascular changes. Portopulmonary hypertension is a well-described and distinct clinical syndrome that is rare in childhood and is associated with a relatively poor prognosis. Occasional patients with histologically advanced disease may remain asymptomatic but present with pulmonary hypertensive crisis. Children with portopulmonary hypertension should be considered at high risk for surgical procedures, and pulmonary hypertensive complications should be excluded as a cause of death in all children dying suddenly in the setting of portal hypertension.

Vascular abnormalities in Adams-Oliver syndrome: cause or effect?

We describe a young girl diagnosed with the Adams-Oliver syndrome (AOS) associated with double outlet right ventricle, portal hypertension, and pulmonary hypertension. We hypothesize that a congenital vascular abnormality is the underlying pathogenesis and that the cutaneous defects characteristically seen in AOS represent the most common manifestation of this. We suggest that AOS should not merely be considered a syndrome consisting of aplasia cutis congenita and terminal transverse limb defects but rather a constellation of clinical findings resulting from an early embryonic vascular abnormality.