Multiple microscopic pulmonary arteriovenous connections in the lungs presenting as cyanosis.

Abstract

Pulmonary arteriovenous fistulae havebeenwell described inthepublished reports'; theright toleft shunt produces arterial oxygen desaturation, cyanosis, finger clubbing, and murmursoverthelungfields. Mostarteriovenous fistulae arerelatively large andcanbediagnosed bypulmonary angiography.' Multiple smallpulmonary arteriovenous fistulae, ortelangiectasia, arerare,2 andusually occurin hereditary haemorrhagic telangiectasia (Osler-RenduWebersyndrome). Veryrarely these fistulae areminute andmaynotberecognised bypulmonary angiography.3 Theassociation between chronic liver disease andmultiple pulmonary arteriovenous anastomoses isalso well recognised.4 5 Thepatient reported hereisunusual inthat hepresented withcyanosis andfinger clubbing without apparent cause. A subsequent diagnosis ofmultiple minute arteriovenous fistulae wasmadeon physiological andpathological grounds, withthelater discovery ofunderlying juvenile hepatic fibrosis with aberrant connections between thesystemic arterial andpulmonary venouscirculations. Casereport A 19yearoldboyhadfirst presented in1977aged 14after hisrelatives hadnoticed that hislips hadbecomebluein thepreceding three months. Hewassymptomfree, leda healthy andunrestricted life, andwasakeencompetitive sportsman. He gavenorelevant family history. He was thin, ofaverage height forhisage,anddeeply cyanosed andhadgross finger clubbing. Noother abnormality was noted ondetailed systematic examination. Thehaemoglobin was15.0 g/dl andthepacked cell volume 0.43. No abnormal haemoglobin pigments were detected. Results ofliver function tests andtheelectrocardiogram andchest radiograph werenormal. Vital capacity wasreduced (2.12 1,predicted 3.551). TLcowasreduced to36%ofthepredicted value. Remaining lung volumes werenormal. Pao2was7.7kPa(58mm Hg),Paco2 4.0 kPa(30mm Hg), pH7.48. Right andleft heart catheterisation, thelatter viaapatent foramen ovale, showed normal pressures andnoevidence ofanintracardiac shunt. Pulmonaryangiography showednothing was abnormal. Breathing 100%oxygen for15minutes produced onarterialoxygen saturation of100%andaPao2of47.6kPa(357