To determine whether AVM volume measurement calculated from the ABC/2 formula is accurate compared to volume calculated by a computer-assisted planimetric method for large AVMs.
To determine whether AVM volume calculated using the ABC/2 method on DSA is accurate when compared to the exact volume calculated from thin-cut axial sections used for SRS planning.
Non-tumor brain samples (from a patient with arteriovenous malformation and from one with epilepsy), normal human astrocytes and cultured endothelial cells were also analyzed: astrocytes and endothelial cells expressed the highest levels of the investigated proteins, mainly MRP1 and MRP5.
The goal of this study was to determine whether angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARB) were associated with lower risk of major gastrointestinal bleeds (GIB) and AVM-related GIBs in continuous-flow left ventricular assist device (CF-LVAD) patients.
We hypothesized that angiotensin-converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) therapy would be associated with a reduced risk of all-cause gastrointestinal bleeding (GIB) and AVM-associated GIB in patients with left ventricular assist devices (LVADs).
In addition to showing that extracranial AVMs demonstrate interrupted elastin and that AVMs and LMs demonstrate abnormal α-smooth muscle actin just as brain AVMS do, our results demonstrate that NOTCH1, 2, 3 and 4 proteins are overexpressed to varying degrees in both the endothelial and mural lining of the malformed vessels in all types of malformations.
In conclusion, no evidence for differences in brain AVM characteristics was observed among HHT gene groups, although we cannot exclude clinically important differences.
These results confirm that the frequency of AVMs differ between patients with HHT1 and HHT2, and that these differences can be detected on physical examination.
Patients with HHT Type 1 (HHT1) had a significantly higher brain AVM prevalence (13.4%, 95% CI 9.5%-17.4%) compared with those with HHT Type 2 (HHT2) (2.4%, 95% CI 1.0%-3.8%) (p < 0.0001).
A total of 135 consecutive adult patients were subjected to mutational screening in ENG and ALK1 genes and instrumental tests to detect AVMs, such as chest-abdomen multislice computed tomography (MDCT), brain magnetic resonance imaging and magnetic resonance angiography (MRI/MRA), upper endoscopy, were offered to all patients, independent of presence of clinical symptoms.
An analysis of the genotype-phenotype correlation is consistent with a more common frequency of pulmonary arteriovenous malformations in patients with ENG mutations than in patients with ACVRL1 mutations in our collective.
Heterozygous loss of activin receptor-like kinase 1 (Alk1) can lead to hereditary hemorrhagic telangiectasia (HHT), which is a kind of vascular disease characterized by direct connections between arteries and veins with the lacking of capillaries, and develops into arteriovenous malformations (AVMs) in later stage.
A higher frequency of pulmonary arteriovenous malformations (AVMs) has been reported for HHT1 while HHT2 is thought to be associated with a lower penetrance and milder disease manifestations.
Genes mutated in HHT (most commonly for endoglin or activin receptor-like kinase (ALK1)) encode proteins that modulate transforming growth factor (TGF)-beta superfamily signalling in vascular endothelial cells; mutations lead to the development of fragile telangiectatic vessels and arteriovenous malformations.
HHT is an autosomal dominant disease with an estimated prevalence of at least 1/5000 which can frequently be complicated by the presence of clinically significant arteriovenous malformations in the brain, lung, gastrointestinal tract and liver.
Endoglin (ENG) and ALK-1 mutations cause hereditary hemorrhagic telangiecstasia (HHT), an autosomal dominant disorder leading to vascular dysplasia in the form of mucocutaneous telangiectasia and visceral arteriovenous malformations (AVMs).
This report highlights ALK1 mutations associated with a variable PAH phenotype, including pulmonary arteriovenous malformations and severe PAH presenting early in life.
The genotype-phenotype correlation was consistent with a higher frequency of pulmonary arteriovenous malformations in patients with ENG mutations than in patients with ACVRL1 mutations in our collective.
HHT-1 is considered a more severe form of the disease with an earlier onset of epistaxis and telangiectases and a higher prevalence of pulmonary arteriovenous malformations than that found in HHT-2 subjects.
The current model for HHT is that ENG or ALK-1 haplo-insufficiency affects angiogenesis and predisposes to vascular dysplasia and arteriovenous malformations.
The results of this study link ACVRL1 (HHT Type 2 gene) to the formation of the clinically sporadic variants of vascular malformations of the CNS most commonly seen in patients with HHT, that is, AVMs and DAVFs.