Diagnosis and treatment of pulmonary arteriovenous malformations in hereditary hemorrhagic telangiectasia: An overview

Abstract

Hereditary hemorrhagic telangiectasia (HHT) or Rendu-Osler-Weber disease is an autosomic dominant disorder, which is characterized by the development of multiple arteriovenous malformations in either the skin, mucous membranes, and/or visceral organs. Pulmonary arteriovenous malformations (PAVMs) may either rupture, and lead to life-threatening hemoptysis/hemothorax or be responsible for a right-to-left shunting leading to paradoxical embolism, causing stroke or cerebral abscess. PAVMs patients should systematically be screened as the spontaneous complication rate is high, by reaching almost 50%. Neurological complications rate is considerably higher in patients presenting with diffuse pulmonary involvement. PAVM diagnosis is mainly based upon transthoracic contrast echocardiography and CT scanner examination. The latter also allows the planification of treatments to adopt, which consists of percutaneous embolization, having replaced surgery in most of the cases. The anchor technique consists of percutaneous coil embolization of the afferent pulmonary arteries of the PAVM, by firstly placing a coil into a small afferent arterial branch closely upstream the PAVM. Enhanced contrast CT scanner is the key follow-up examination that depicts the PAVM enlargement, indicating the various mechanisms of PAVM reperfusion. When performed by experienced operators as the prime treatment, percutaneous embolization of PAVMs, is a safe, efficient and sustained therapy in the great majority of HHT patients.

The Lung in Hereditary Hemorrhagic Telangiectasia

“…Increasingly, Amplatzer vascular plugs are recommended, as these have greater efficacy and appear to have a lower risk of recanalization [67,[84][85][86] . Other devices are occasionally used, especially for PAVMs with very large feeding arteries [84] .…”

Pulmonary Arteriovenous Malformations: Current Technique of Transcatheter Embolization and Subsequent Management

“…In the scaffold technique, the first positioned coil creates a scaffold and permits the blockage of other devices. By packing the decreasing diameter devices, optimal occlusion of the feeding artery can be achieved [19]. The double microcatheter technique uses the concept of securely bracing coils beside one another to achieve a stable configuration.…”

Hereditary haemorrhagic telangiectasia

“…PAVMs are abnormal direct communications between the pulmonary arterial and venous circulations, bypassing the capillary bed between the pulmonary and systemic circulations (43) .…”

“…The gold standard screening method is with transthoracic contrast echocardiography, which has a sensitivity of 93% (42) ; if this is positive then formal computed tomography (CT) is performed to plan treatment, although CT alone is used in some units (43,44) . Percutaneous embolotherapy is the treatment of choice, with excellent success rates (44,47,48) .…”