Reliability of contrast echocardiography to rule out pulmonary arteriovenous malformations and avoid CT irradiation in pediatric patients with hereditary hemorrhagic telangiectasia.

BACKGROUND: The overall risk of cancer is higher in people exposed to computed tomography (CT) scans in childhood or adolescence compared to adults. Transthoracic contrast echocardiography (TTCE) has recently been used to screen for pulmonary arteriovenous malformations (PAVMs) in children with hereditary hemorrhagic telangiectasia (HHT), but the value of TTCE to rule out PAVMs and avoid chest CT radiation has yet to be discussed. METHODS: Between 2003 and 2013, 92 pediatric patients with ≥3 Curaçao criteria and/or genetic mutation underwent TTCE and chest CT on the same day. We used the classification proposed by Barzilai for TTCE quantification of shunting. We considered CT findings as negative when no PAVMs or only one microscopic PAVM was detected. RESULTS: Mean age was 11.2 ± 4.1 years. The shunt was grade 0 on TTCE in 27.3%, grade 1 in 17%, grade 2 in 29.6%, grade 3 in 23.9%, and grade 4 in 2.2%. We found PAVMs on chest CT in 52.2%. All the patients with a grade 0 or 1 had a negative CT. The sensitivity and specificity of TTCE for the detection of PAVMs were 100% and 95.1%, respectively. The negative predictive value (NPV) was 100% and the positive predictive value (PPV) was 96%. CONCLUSIONS: A low-grade classification (Barzilai 0 or 1) could presumably exclude the presence of PAVMs and allow CT irradiation to be avoided in children and adolescents. The screening algorithm using TTCE first would allow more than 40% of the pediatric patients screened for PAVMs to be spared the radiation dose of CT.

Higher prevalence of splenic artery aneurysms in hereditary hemorrhagic telangiectasia: Vascular implications and risk factors.

BACKGROUND: Splenic artery aneurysm (SAA) is a rare but potentially fatal condition. Rupture results in 25% mortality up to 75% in pregnant women with 95% fetal mortality. Brief reports suggest an increased risk of developing SAA in patients with HHT. METHODS: We analyzed enhanced multidetector CT data in 186 HHT patients matched (gender and ± 5 year old) with 186 controls. We screened for SAA and recorded diameter of splenic and hepatic arteries and hepatic, pancreatic and splenic parenchymal involvements. We determined by univariate and multivariate analysis, the relationship with age, sex, genetic status, cardiovascular risk factors (CVRF) and visceral involvement. RESULTS: SAA concerned 24.7% of HHT patients and 5.4% of controls, p<0.001. Factors associated with increased risk of SAA in HHT were female gender (p = 0.04, OR = 2.12, IC 95% = 1.03-4.50), age (p = 0.0003, OR = 1.04, 95% CI = 1.02-1.06) and pancreatic parenchymal involvement (p = 0.04, OR = 2.13, 95% CI = 1.01-4.49), but not type of mutation, hepatic or splenic parenchymal involvements, splenic size or splenic artery diameter or CVRF. CONCLUSIONS: We found a 4.57 higher rate of SAA in HHT patients without evidence of splenic high output related disease or increased CVRF. These results suggest the presence of a vascular intrinsic involvement. It should lead to screening all HHT patients for SAA. The vasculopathy hypothesis could require a change in management as screening of all systemic arteries and even the aorta and to further research in the field.