A Lacout

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

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.

Tomosynthesis: A new chest imaging technique

Tomosynthesis;Spatial resolution;CT scan;Tomography;IrradiationTomosynthesis isanewmedicalimagingtechnique,arealdigitalrevivalof‘‘conventional’’tomography that became obsolete a long time ago. The rapid growth of digital radiologyand plane sensors has contributed to the reappearance of this imaging procedure.

Liver metastasis of a mucinous colonic carcinoma mimicking a haemangioma in T2-weighted sequences.

We report the case of a patient with a single liver metastasis of a mucinous colonic carcinoma that mimics a haemangioma in T2‐weighted sequences. Although a very high T2 signal in non‐cystic lesions is highly specific for the diagnostic of haemangioma, the use of gadolinium‐enhancement MRI is recommended. In patients with a history of neoplasia, the diagnosis of benign liver nodules should be made with caution.

Metformin as possible therapy of pulmonary arterio venous malformation in HHT patients

Hereditary hemorrhagic telangiectasia (HHT) or Rendu-Osler-Weber disease is an autosomic dominant disorder, which is characterized by the development of multiple arteriovenous malformations. Pulmonary arteriovenous malformations may either rupture or be responsible for a right-to-left shunting leading to paradoxical embolism causing stroke or cerebral abscess. Metformin may harbor a pleiotropic action, (a) decreasing inflammation (via anti COX 2 pathway and other mechanism), (b) decreasing COX 2 and VEGF mediated angiogenesis, (c) increasing negative angiogenic regulation pathway by stimulating SMAD 2/3 expression either directly or via the AMPK pathway and preventing from pulmonary hypertension development and (d) diminushin oxidative stress. An animal model could be experimented to show its effects on PAVM formation. Metformin could also be tested in human individuals, particularly in patients presenting a diffuse HHT type with tiny PAVM. Metformin may be indicated as a prophylactic or curative therapy in HHT patients presenting with initial lung involvement. Metformin may be proposed to prevent from pulmonary arteriovenous malformation development and subsequent related complications.

Roles of cyclooxygenase 2 and hepatic venous flow in patients with HHT or hepatopulmonary syndrome

BACKGROUND Hereditary hemorrhagic telangiectasia (HHT) and hepatopulmonary syndrome are disorders characterized by the development of multiple pulmonary arteriovenous malformations (PAVM). PRESENTATION OF THE HYPOTHESIS COX2 may be at the origin of a cascade of pro inflammatory events to favour angiogenesis and PAVM development. TESTING THE HYPOTHESIS HHT and hepatopulmonary syndrome mouse models may be used to show its effects on PAVM formation. Anti COX-2 therapy could also be tested in human individuals, particularly in patients presenting a hepatopulmonary syndrome or HHT with small PAVM. IMPLICATION OF THE HYPOTHESIS PAVMs are one of the main causes of morbidity in patients presenting with HHT disease, owing to the risks of rupture as well as paradoxical embolism exposing to stroke and/or cerebral abscess. Percutaneous embolization has become the treatment of choice of PAVM. Anti COX2 may prevent from PAVM development and subsequent related complications and avoid either surgery and/or percutaneous embolization and thus subsequent related complication.