Predicting the size of pulmonary arteriovenous malformations on chest computed tomography: a role for transthoracic contrast echocardiography

Abstract

This study aimed to investigate whether pulmonary shunt grade on transthoracic contrast echocardiography (TTCE) predicts the size of pulmonary arteriovenous malformations (PAVMs) on chest computed tomography (CT) and subsequent feasibility for transcatheter embolotherapy.We prospectively included 772 persons with possible or definite hereditary haemorrhagic telangiectasia, who underwent both TTCE and chest CT for screening of PAVMs. A quantitative three-point grading scale was used to classify the pulmonary shunt size on TTCE (grade 1-3). Transcatheter embolotherapy was performed for PAVMs deemed large enough for endovascular closure on chest CT.TTCE documented pulmonary shunting in 510 (66.1%) patients. The positive predictive value of a pulmonary shunt grade 1, 2 and 3 on TTCE for presence of PAVMs on chest CT was 13.4%, 45.3% and 92.5%, respectively (p,0.001). None of the 201 persons with a pulmonary shunt grade 1 on TTCE had PAVMs on chest CT large enough for transcatheter embolotherapy, while 38 (25.3%) and 123 (77.4%) individuals with a pulmonary shunt grade 2 and 3 on TTCE, respectively, underwent endovascular closure of PAVMs.Pulmonary shunt grade on TTCE predicts the size of PAVMs on chest CT and their feasibility for subsequent transcatheter embolotherapy. Chest CT can be safely withheld from all persons with a pulmonary shunt grade 1 on TTCE, as any PAVM found in these subjects will be too small for transcatheter embolotherapy. @ERSpublications Chest CT can be safely withheld from persons with pulmonary shunt grade 1 on TTCE

How to follow-up patients with hereditary haemorrhagic telangiectasia and suspected pulmonary arteriovenous malformations

“…The vascular malformations predispose patients to severe complications due to paradoxical systemic emboli of thrombotic or septic origin, such as stroke and brain abscess [2][3][4][5]. The treatment of choice for PAVMs is transcatheter embolotherapy, although concerns are emerging regarding the long-term consequences of this procedure, especially in children [6].Because of the risk of severe complications, international guidelines recommend screening patients with HHT for the presence of PAVMs at the time of initial clinical evaluation and also after puberty, after pregnancy, within 5 years preceding a planned pregnancy, and otherwise every 5-10 years [7]. Transthoracic contrast echocardiography (TTCE) is the first-line screening technique for the detection of PAVMs in HHT [7].…”

“…In expert hands, it has excellent sensitivity and negative predictive value for the presence of PAVMs in children and adults. Several grading scales are used in different HHT centres to quantify the pulmonary RLS size [6][7][8]. Microbubbles of air in agitated saline may expose patients with RLS to the risk of cerebral air emboli inducing migraine, blurred vision, numbness and paraesthesia, but these symptoms resolve quickly without residual side effects [9,10].…”

“…The absence of, or a small, pulmonary RLS (i.e. a low grade on TTCE) is associated with no risk of neurological complications and with PAVMs too small for embolisation [5,7]. …”

“…Transthoracic contrast echocardiography (TTCE) is the first-line screening technique for the detection of PAVMs in HHT [7]. In expert hands, it has excellent sensitivity and negative predictive value for the presence of PAVMs in children and adults.…”

“…Chest computed tomography (CT) is considered the gold standard diagnostic tool for PAVMs as it enables visualisation of the vascular malformations (except microscopic ones) and provides essential information on their characteristics (shape, location, size of the feeding arteries, size of the aneurismal sac, etc.). Recent studies have reported that, in patients with HHT, the grade of pulmonary RLS on TTCE predicts the size of PAVMs on chest CT and the feasibility of subsequent transcatheter embolotherapy [7]. The absence of, or a small, pulmonary RLS (i.e.…”