Diagnosis Of Pulmonary Arteriovenous Malformations Research Articles

Pulmonary arteriovenous fistulas in patients with hereditary hemorrhagic telangiectasia: role of MR angiography

The aim of this work is to establish the accuracy of pulmonary magnetic resonance angiography (MRA) compared to multidetector computed tomography (MDCT) and pulmonary angiography in the diagnostic evaluation of pulmonary arteriovenous malformations (PAVMs) in patients with hereditary hemorrhagic telangiectasia. Eight consecutive patients underwent MRA, MDCT and pulmonary angiography. All patients were carriers of PAVMs amenable to endovascular treatment. The parameters we have evaluated were the presence, the number of fistulas and the diameter of the feeding artery of the malformation. In all cases, the findings of the three tests were comparable. In only one case, MR images were considered qualitatively poorer than MDCT, although sufficient for the recognition of the lesion located in the hilum. The diameters of the arteries showed no statistically differences between MRA and CT. In conclusion, the MRA technique was found to be valid and reliable in the diagnosis of PAVMs in patients with HHT.

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.

10. A case of right middle lobe pulmonary arteriovenous malformation presenting as non-resolving pneumonia

Background Pulmonary arteriovenous malformations (PAVMs) are direct communications between the smaller pulmonary arteries and veins. These lesions allows blood to bypass the capillary system, flowing from arteries directly into veins. Case history The patient was a 51-year-old male, non-hypertensive, non-diabetic, asthmatic who came in due to recurrent episodes of haemoptysis. Initially this was treated as a case of pneumonia and/or pulmonary tuberculosis (PTB). A CT scan with contrast and CT angiogram were done and revealed AV malformation. He was referred to surgical service for elective thoracotomy and right middle lobe lobectomy. Histopathological findings showed lung tissue exhibiting areas of variably sized thin and partially thick vascular channels. The area was in close proximity to a bronchus and accompanying medium-sized arteries, predominantly extended to the pleural lining. Discussion The diagnosis of PAVM should be suspected in patients with any of the following presentations: (1) one or more pulmonary nodules associated with typical roentgenographic findings, (2) mucocutaneous telangiectases, and (3) unexplained findings such as dyspnoea, haemoptysis, hypoxaemia, polycythaemia, clubbing, cyanosis, cerebral embolism, or brain abscess. A practical approach would be to screen patients initially with chest radiograph, followed by shunt measurement by 100% oxygen. Our case was confirmed with PAVM by CT scan and CT angiogram and underwent right middle lobectomy. Other treatment options are embolisation and lungtransplantation. Conclusion The rarity of PAVMs and the variability of presentation posed a great challenge. Our case, in particular presenting as a non-resolving pneumonia with an unusual location, is a significant contribution to our registry. Its rarity should alert clinicians to include PAVMs in the differential diagnosis of patients with pneumonia and haemoptysis.

Early neonatal complications from pulmonary arteriovenous malformations in hereditary hemorrhagic telangiectasia: case report and review of the literature

Hereditary hemorrhagic telangiectasia (HHT) is a rare but life-threatening disease characterized by multi system telangiectasias and arteriovenous malformations (AVM). Complications in adults have been reported extensively, but neonatal (NN) complications have only been published in incidental case reports. In this paper, we present a literature review on NN pulmonary AVM related to HHT, following our own experience with a NN death due to this disease. As prenatal diagnosis of pulmonary AVM is feasible, we recommend that a family history of HHT should be an indication for expertise prenatal anomaly scanning, in order to organise optimal NN support at birth.

Surgically Treatable Pulmonary Arteriovenous Fistula

Arteriovenous fistuli are congenital malformations. Usually symptoms depend on size of the lesion. Lesions smaller than 2 cm are often asymptomatic. The most common symptoms are dyspnea, palpitation and fatigue. Cyanosis is indicative of right to left shunt. Helical computed tomography (CT) scan is a helpful diagnostic tool in this case. Surgery is the treatment of choice in patients with isolated lesions. Embolization is a selective method in patients with multiple or bilateral lesions. The patient was a 13-year-old boy complaining of cyanosis of lips and nails as well as dyspnea for 5 years. Definite diagnosis of pulmonary arteriovenous malformation (PAVM) in the right middle lobe was based on CT angiography. The patient underwent a thoracotomy and lobectomy of the right middle lobe. After surgery cyanosis and dyspnea were completely resolved.

Chronic migraine and transient ischemic attack due to isolated pulmonary arteriovenous malformation successfully treated with transcatheter embolization

A 37-year-old woman, nonsmoker, with a history of chronic migraines with aura, was referred to our emergency room due to dysarthria and left faciobrachial paresis. Her family history was unremarkable. Physical examination was normal except for a mild oxygen desaturation (88% on room air). Electrocardiogram, echocardiography, peripheral venous and arterial Doppler ultrasound, and brain magnetic resonance imaging were normal. However, transcranial Doppler analysis showed a significant (shower pattern) right-to-left shunt late after isotonic saline. This pattern was present at rest and did not significantly change after Valsalva maneuver. At chest radiograph, a lobular smoothmargined opacity in the right lower lobe made us suspect the diagnosis of pulmonary arteriovenous malformation (PAVM). Chest computed tomography (CT) showed a large complex PAVM fed by two large and tortuous descending pulmonary arteries and draining through a straight vessel directed posterosuperiorly to the right lower pulmonary vein (Fig. 1). Thus, cardiac catheterization was planned to occlude the vascular malformation. The patient’s informed consent to the procedure and agreement with the thoracic surgeons were obtained. The procedure was performed with local anesthesia through the femoral vein entry. Pulmonary angiography confirmed the presence of multiple large PAVMs into the right lower lobe fed by a single 1.1-cm-large vessel originating from the right inferior pulmonary artery (Fig. 2a). Transcatheter embolization of the feeding vessel was achieved with a 14-mm-large Amplatzer Vascular Plug type II (AGA Medical, Golden Valley, Minnesota, USA) device (Fig. 2b) and resulted in a sudden increase in the oxygen saturation, from 88 to 96% on room air. Clinical status and

Congenital pulmonary arteriovenous malformation: a rare cause of cyanosis in childhood

Pulmonary arteriovenous malformation (PAVM) is a rare condition in which there is abnormal connection between pulmonary arteries and veins. The disorder usually appears in late childhood or early adult life, with dyspnea on exertion, clubbing or cyanosis. We present two patients with severe cyanosis and their work-up to diagnosis of PAVM, as a rare cause of cyanosis in childhood.

Pulmonary arteriovenous malformations after a Fontan operation in the left isomerism and absent inferior vena cava☆

To evaluate the occurrence of pulmonary arteriovenous malformations after a Fontan operation in the left isomerism and absent inferior vena cava. We retrospectively reviewed 19 patients with the left isomerism and absent inferior vena cava who underwent Fontan operations at our institution. We divided the patients into two groups: bilateral superior vena cava (group A, n=9), and single superior vena cava (group B, n=10). Median age at Fontan operation was 6.2 years (1.0-24.1). Diagnosis of pulmonary arteriovenous malformations was made by pulmonary angiography and bubble contrast echocardiography. Median follow-up was 5.3 years (0.2-17.3) with one hospital death. Seven patients suffered from pulmonary arteriovenous malformations. In six out of the seven patients, the occurrence of pulmonary arteriovenous malformations was related to biased pulmonary perfusion of the hepatic venous flow. In group A, the distance between the dominant superior vena cava (which the venous flow from the lower half of the body drains into) and the hepatic venous channel over the distance between the smaller superior vena cava and the hepatic venous channel was larger in patients with pulmonary arteriovenous malformations than in patients without pulmonary arteriovenous malformations (3.83+/-1.28 vs 1.53+/-1.45, p=0.071). In group B, pulmonary arteriovenous malformations developed in two patients whose venous channels did not overlap. Pulmonary arteriovenous malformations developed in only one patient after we changed the hepatic venous channel design to approximate the hepatic venous channel to the dominant superior vena cava as closely as possible. We might prevent pulmonary arteriovenous malformations in patients with the left isomerism and absent inferior vena cava by designing the venous channels to achieve better mixing of the superior vena cava and the hepatic venous flow.

The role of echocardiography in prenatal diagnosis of pulmonary arteriovenous malformation

The role of echocardiography in prenatal diagnosis of pulmonary arteriovenous malformation

A 24-year-old man with chest pain, hemoptysis, and hypoxia

The diagnosis of pulmonary arteriovenous malformations in patients remains a diagnostic challenge to the emergency physician. Pulmonary arteriovenous malformations are abnormal direct connections that shunt unoxygenated blood from pulmonary arteries to pulmonary veins, resulting in hypoxia. They represent a rare clinical entity and are usually associated with hereditary hemorrhagic telangiectasia. We report a case of a young man who presented to the emergency department with an acute onset of right-sided chest pain, and vital signs and laboratory findings that did not clinically correlate with his history or physical examination. To our knowledge, there are no case reports of pulmonary arteriovenous malformations described in the emergency medicine literature.

Estimates of maternal risks of pregnancy for women with hereditary haemorrhagic telangiectasia (Osler–Weber–Rendu syndrome): suggested approach for obstetric services

Hereditary haemorrhagic telangiectasia (HHT) affects 1 in 5-8000 individuals. Pregnancy outcomes are rarely reported. The major reason is that most women do not have their HHT diagnosed prior to pregnancy. Using a large well-characterised series, we studied all pregnancies known to have occurred in HHT-affected women, whether or not their diagnosis was known at the time of pregnancy. Our aim was to estimate rates and types of major complications of HHT in pregnancy, to guide management decisions. Cohort study, with prospective, retrospective and familial components. Tertiary referral centre population. All 262 pregnancies in the 111 women with HHT and pulmonary arteriovenous malformations (PAVMs) reviewed between 1999 and 2005 were studied. Eighty-two women (74%) did not have a diagnosis of HHT/PAVM at the time of pregnancy. 222 pregnancies in their 86 HHT-affected relatives were also studied. PAVM bleed, stroke and maternal death. Thirteen women experienced life-threatening events during pregnancy: 1.0% (95% CI 0.1-1.9) of pregnancies resulted in a major PAVM bleed; 1.2% (0.3-2.2%) in stroke (not all were HHT related); and 1.0% (0.13-1.9%) in maternal death. All deaths occurred in women previously considered well. In women experiencing a life-threatening event, prior awareness of HHT or PAVM diagnosis was associated with improved survival (P = 0.041, Fisher's exact test). Most HHT pregnancies proceed normally. Rare major complications, and improved survival outcome following prior recognition, means that pregnancy in a woman with HHT should be considered high risk. Recommendations for pregnancy management are provided.

Primary determinants of ischaemic stroke/brain abscess risks are independent of severity of pulmonary arteriovenous malformations in hereditary haemorrhagic telangiectasia

Background: Brain abscesses and ischaemic strokes complicate pulmonary arteriovenous malformations (PAVMs). At risk individuals are poorly recognised. Stroke/abscess risk factors have not been defined. Methods: A cohort study of 323...

Diagnosis: Pulmonary arteriovenous malformation (PAVM)

Diagnosis: Pulmonary arteriovenous malformation (PAVM)

Comparison of contrast echocardiography versus cardiac catheterization for detection of pulmonary arteriovenous malformations

Because clinical diagnosis of pulmonary arteriovenous malformations (AVMs) is difficult and cardiac catheterization invasive, contrast echo has been used to aid in the diagnosis. Correlation between contrast echo and catheterization data in these patients remains poorly defined. We examined the ability to detect pulmonary AVMs by contrast echocardiography, pulmonary angiography, and pulmonary vein saturations in patients who have undergone cavopulmonary (Glenn) shunts. Pulmonary vein saturations were obtained from catheterization reports. Blinded observers reviewed angiographic and contrast echo data retrospectively in 27 patients who had undergone a Glenn shunt and in 19 controls with biventricular hearts. Contrast echo was positive in 68 of 99 lungs (69%). Angiography showed AVMs in 65 of 98 lungs (66%). Pulmonary vein desaturation was found in 13 of 45 lungs sampled (29%). Only 10 of 38 lungs with positive contrast echo had pulmonary vein desaturation, but only 1 patient had pulmonary vein desaturation without positive contrast echo. The degree of desaturation did not correlate with severity of contrast echo return; 6 of 11 patients with 3+ contrast echo studies had normal pulmonary vein saturations. In a control group of patients with biventricular hearts, only 1 of 19 (5.3%) contrast echos was weakly positive. Contrast echo correlates poorly with angiography and pulmonary vein saturation for evaluation of AVMs. Contrast echo is extremely sensitive and often positive despite normal pulmonary vein saturation. Assessment of pulmonary vein desaturation in 100% oxygen may improve its sensitivity and correlation with contrast echo. Additional studies are needed to follow patients with mildly positive contrast echo studies to enable determination of their clinical relevance.

Pulmonary arteriovenous malformations: three-dimensional gadolinium-enhanced MR angiography-initial experience.

To determine whether three-dimensional gadolinium-enhanced magnetic resonance (MR) angiography could be used to identify pulmonary arteriovenous malformations (PAVMs) and to accurately identify the size and number of feeding arteries. Eight patients suspected of having PAVM were examined with three-dimensional MR angiography at 1.5 T. Images were reviewed by a single radiologist blinded to conventional angiographic findings who evaluated each image for the size, number, and location of PAVMs, as well as for the size and number of feeding arteries. Five patients underwent conventional angiography with embolization therapy, and one patient underwent lobectomy. Two patients did not undergo either surgery or angiography. Three-dimensional MR angiography revealed nine (90%) of 10 PAVMs that were confirmed at conventional angiography (n = 9) or examination of a surgical specimen (n = 1). The single PAVM that was not identified prospectively at MR angiography was small (3-4 mm) and peripheral. Two additional PAVMs were identified in the two patients who did not undergo surgery or angiography. Three-dimensional MR angiography is a promising technique for use in the diagnosis of PAVM, although small (<5-mm) PAVMs may be more difficult to identify with the technique. The technique is a particularly useful means of noninvasively demonstrating the size and number of feeding arteries prior to treatment.

Contrast echocardiography for detection of pulmonary arteriovenous malformations

Background Pulmonary arteriovenous malformations (PAVMs) lead to stroke, brain abscess, and hemorrhage in hereditary hemorrhagic telangiectasia (HHT). The current screening approach for PAVMs in HHT patients with chest radiograph (CXR) and oxygen shunt study has not been validated and is thought to be insensitive. We hypothesized that agitated saline contrast echocardiography (ECHO) would be a useful screening test for PAVMs. Methods and Results A total of 106 sequential HHT patients underwent screening for PAVMs with ECHO in a prospective study. If the test was positive, or if the CXR or shunt study suggested PAVMs, pulmonary angiography was performed. A positive ECHO was defined as appearance of bubbles in the left atrium after injection of agitated saline solution. A positive shunt study was defined as a partial pressure of oxygen in arterial blood <500 mm Hg while breathing 100% oxygen. The mean age was 41 years (range 15-80 years); 66% were female. Forty-four patients had positive ECHO. Forty-one of the 44 patients underwent angiography. Three patients declined further testing. Thirty-three of the 41 patients who underwent angiography were diagnosed with PAVMs. Of the 62 patients with a negative ECHO, 18 underwent angiography because of either a shunt study or CXR that was suggestive of PAVMs. Of these 18 patients, 2 had PAVMs. In the total population of 106 patients, 35 (33%) had PAVMs. ECHO was the only positive screening test in 11 of 35 (31%) patients. The diagnosis of PAVMs in these 11 patients would have otherwise been missed. Conclusions ECHO is a useful screening tool for PAVMs in HHT. (Am Heart J 2001;141:243-6.)

Pulmonary Arteriovenous Malformations

Helical CT scan (HCT), a noninvasive method, can detect pulmonary arteriovenous malformations (PAVMs). Its sensitivity is superior to that of global digitalized angiography, but patients receive a significant dose of radiation during diagnostic HCT. We compared HCT to contrast-enhanced pulmonary magnetic resonance angiography (CEMRA), a new noninvasive radiation-free method, in the diagnosis of PAVMs. Five consecutive patients with PAVMs underwent HCT, CEMRA, and pulmonary artery digital subtraction angiography (PADSA). CEMRA was performed during the pulmonary arterial phase of an IV bolus of gadolinium. PADSA was performed during the embolization procedure. All images were examined for PAVMs. The site and size of aneurysms were specified, as well as the diameter of the vascular pedicles. Thirty PAVMs were detected by CEMRA and 38 by HCT. All 20 PAVMs at least 5 mm in diameter and 10 of the 18 PAVMs < 5 mm in diameter identified on HCT were also identified by CEMRA. Whatever the site, all PAVMs with a feeding artery diameter of at least 3 mm (ie, PAVMs with clinical consequences) were detected by CEMRA. No false-positive results were obtained with CEMRA. CEMRA therefore had a sensitivity of 78% and a specificity of 100%. CEMRA, a nonionizing and noninvasive procedure, has high sensitivity and specificity for the diagnosis of clinically relevant PAVMs.

Diagnosis of pulmonary arteriovenous malformations by colour Doppler ultrasound and amplitude ultrasound angiography

BACKGROUNDThe clinical value of colour Doppler ultrasound and amplitude ultrasound angiography in the diagnosis and follow up of pulmonary arteriovenous malformations (PAVM) was investigated.METHODSSix consecutive patients suspected by clinical appearance...

Transesophageal Echocardiography in an Operation for Pulmonary Arteriovenous Malformation

Transesophageal echocardiography has been described as a useful tool in the diagnosis of pulmonary arteriovenous malformations. We describe a case in which intraoperative transesophageal echocardiography was used to aid localization and ensure complete surgical ligation.

Applications of colour Doppler ultrasound in the diagnosis of chest diseases.

Colour Doppler ultrasound (US) or colour Doppler imaging is a new imaging modality that can simultaneously display blood flow information and Doppler spectral analysis. This new technique provides an opportunity to assess pulmonary blood flow and perfusion non-invasively. Colour Doppler US has many potential applications in diseases of the chest. Colour Doppler imaging is useful in assisting the diagnosis of pulmonary arteriovenous malformation and pulmonary sequestration. The 'fluid colour sign' can be used to detect minimal effusion amenable to thoracentesis. Colour Doppler US can be used to assess the angiogenesis of a lung tumour and may be helpful in differentiating a malignant tumour from a benign one. Colour Doppler US can be used to guide a transthoracic needle biopsy and improve the safety of this invasive procedure. Colour Doppler US can demonstrate the vascular patterns and assess the regional haemodynamic changes of a pulmonary consolidation. The information of spectral wave analysis is helpful for understanding the haemodynamic changes of a pulmonary consolidation. Colour Doppler US is useful in assessing perfusion and reperfusion status of a pulmonary infarction. The recent advent of amplitude US angiography further improved the sensitivity of colour Doppler US in detecting blood flow signal without angle restriction. The potential application of these new techniques in chest diseases may need further exploration.