Pulmonary and systemic arteriovenous fistulas in patients with left isomerism

Abstract

Hepatic venous blood has been thought to play some role as a vasoactive agent in the development of pulmonary arteriovenous fistulas in patients with congenital heart disease. During the last 15 years, we have observed pulmonary arteriovenous fistulas in 3, and systemic arteriovenous fistulas in 2, patients from our 16 cases of left isomerism. During the same period, neither pulmonary nor systemic arteriovenous fistulas were detected among 50 patients with right isomerism. Pulmonary arteriovenous fistulas had developed in the absence of surgery in 1 of the patients. Both pulmonary and systemic fistulas were detected in an another patient, in whom the hepatic venous blood bypassed the pulmonary circulation. The level of somatostatin, which is known to reduce splanchnic blood flow, was high in the systemic venous blood of this patient. Although the mechanism of development of the fistulas has yet to be clarified, we should be aware that not only pulmonary, but also systemic arteriovenous fistulas can be found in patients with left isomerism, even prior to any surgical intervention.

Venovenous malformation: a common finding after Kawashima operation

“…The awareness of the presence of VVM provides the opportunity for timely and precise intervention if symptomatic cyanosis occurs, without the need for exhaustive investigation of the patients in the early period after surgery. We agree with others [2][3][4]9] that, earlier referral for hepatic vein redirection in the patient with good haemodynamics for conversion to a total cavopulmonary anastomosis may be considered.…”

The biological “scrabble” of pulmonary arteriovenous malformations: considerations in the setting of cavopulmonary surgery

“…[37][38][39]41,42,73,74 Yet there are some patients with polysplenia and interruption of the inferior caval vein with apparently normal hepatic function who have not undergone cavopulmonary surgery but who still develop pulmonary arteriovenous malformations. 66,[75][76][77] Interestingly pulmonary arteriovenous fistulas have not yet been identified in unoperated patients with right isomerism, although this group must be most uncommon. 78 The patient reported by Papagiannis et al, for example, was found to have hypoplasia of the intrahepatic portal venous branches and a portal-systemic shunt.…”

Contribuição para o diagnóstico e o tratamento das fístulas arteriovenosas pulmonares após a operação de Glenn bidirecional

“…One patient with left atrial isomerism and systemic and pulmonary arteriovenous fistulae had an elevation in somatostatin, an antagonist of glucagon, with values around 92.8 pg/mL, when the normal level is 28 pg/mL. The increase in somatostatin may reflect a homeostatic mechanism to prevent the excessive vasodilation caused by an unknown mediator, which may account for the appearance of the fistulae 36 . In addition, the unknown vasodilator agent may reach the systemic circulation without being metabolized by the liver, and, therefore, may similarly produce systemic arteriovenous fistulae.…”

“…Vasodilators originating in the mesenteric venous blood, such as glucagon, have been proposed as the major agents involved in the appearance of the fistulae 25 . Kawata et al 36 reported the appearance of pulmonary arteriovenous fistulae in 3 of 16 patients with left atrial isomerism and cyanogen congenital heart diseases and no previous operation, 2 of whom also had systemic arteriovenous fistulae. These results were compared with those of 50 patients with right atrial isomerism, but none of them developed fistulae, either pulmonary or systemic.…”

“…The following hypothesis may be formulated: in these cases, vasodilator agents, such as glucagon and vasoactive intestinal peptides originating from the mesenteric circulation, are not metabolized by the liver and pass directly to the lungs, heart, and other organs, stimulating the formation of the fistulae. Hypersensitivity of the pulmonary endothelium or a reduction in the sensitivity of the pulmonary vasculature to an endogenous vasoconstrictor should be considered alternative mechanisms 36 .…”