JAOCR at the Viewbox: Hereditary Hemorrhagic Telangiectasia

Hereditary Hemorrhagic Telangiectasia: A Review

A 56-year-old woman with a history of hereditary hemorrhagic telangiectasia (HHT) and positive for endoglin gene mutation presented with worsening hypoxia requiring mechanical ventilation secondary to right-to-left shunting from pulmonary arteriovenous malformations (AVMs). Interventional radiology was consulted for further evaluation and treatment with angiogram and embolization.

Initial CT angiogram demonstrated multiple pulmonary AVMs including those in the right lower lobe (asterisk in Figure A). The patient underwent pulmonary angiography that demonstrated concordant findings to the cross-sectional imaging (asterisks in Figure B and C). Coil embolization of the AVMs was performed. A post-interventional digitally subtracted angiogram (Figure D) displayed coil embolization of the right lower lobe pulmonary AVM (asterisk). Following intervention, the patient’s hypoxia improved, and she was weaned off mechanical ventilation to oxygen via nasal cannula and was discharged home.

Hereditary hemorrhagic telangiectasia, also known as Osler-Weber-Rendu syndrome, is an autosomal dominant disease manifested by AVMs and telangiectasia. Prevalence of HHT is 1 in 5000 to 10 000. Clinical diagnosis is centered on the presence of 3 out of 4 Curacao criteria, which includes: recurrent epistaxis, skin and mucosal telangiectasia, visceral AVM, and family history of HHT. Three genes have been associated with HHT: endoglin, aktivin, and SMAD4.^1,2

Pulmonary AVMs have a strong association with HHT due to a mutation in the endoglin gene. These AVMs are high-flow shunts that can cause hypoxia, dyspnea, and hemoptysis. Pulmonary AVMs put patients at risk of brain abscess and stroke. AVMs in the lungs are commonly found in the lower lobes and have the radiographic appearance of a pulmonary nodule or nidus with a large feeding artery and draining vein. Treatment of pulmonary AVMs with coil embolization should be considered when the feeding artery is > 3 mm.^1,2 In addition to the lungs, AVMs can also be seen elsewhere, including the central nervous system and gastrointestinal tract.

References

1. Carette MF, Nedelcu C, Tassart M, et al. Imaging of hereditary hemorrhagic telangiectasia. Cardiovasc Intervent Radiol 2009;32(4):745-757.
2. Meek ME, Meek JC, Beheshti MV. Management of pulmonary arteriovenous malformations. Semin Intervent Radiol 2011;28(1):24-31.