Malformaciones arteriovenosas pulmonares: presentación de un caso clínico pediátrico y revisión de la literatura / Pulmonary arteriovenous malformations: presentation of a pediatric case and review of the literature

Las malformaciones arteriovenosas pulmonares (MAVP) consisten en comunicaciones directas entre el sistema arterial y el sistema venoso pulmonar, sin paso de la sangre por el lecho capilar, produciéndose un cortocircuito de derecha a izquierda extracardíaco, pueden ser congénitas o adquiridas. Algunos casos pueden ser asintomáticos, en cambio en otros pueden ocasionar diversas manifestaciones clínicas y se pueden asociar a complicaciones severas. En niños se observa una baja incidencia y son más frecuentes las formas congénitas. La MAVP se debe sospechar por las manifestaciones clínicas y las imágenes de la radiografía de tórax (RxTx) y su confirmación se realiza mediante una AngioTomografía Computada (TC) de tórax. La embolización endovascular es actualmente el tratamiento de elección, con excelentes resultados, aunque requiere de un seguimiento posterior y de un operador experimentado. Reportamos el caso de una niña que ingresó con clínica muy sugerente, incluyendo: disnea, acropaquia, cianosis periférica, e hipoxemia refractaria. Sin embargo, inicialmente el cuadro clínico fue confundido con una crisis asmática. La Angio-TC de tórax confirmó el diagnóstico y el tratamiento mediante embolización endovascular resultó exitoso.

Pulmonary arteriovenous malformations (PAVM) are communications between the arterial and the pulmonary venous system, without passage of blood through the capillary bed, causing a left to right extracardiac shunt. Some cases may be asymptomatic, while others may cause various clinical manifestations and may be associated with severe complications. In children a low incidence is observed, and congenital forms are more frequent. PAVM should be suspected by clinical manifestations and chest x-ray imaging and confirmed by chest Computed Tomography Angiography (CTA). Endovascular embolization is currently the treatment of choice, with excellent results, although it requires subsequent follow-up. We report a patient who was admitted with a very suggestive clinical history, including: dyspnea, clubbing, peripheral cyanosis, and severe hypoxemia, refractory to oxygen therapy. However, initially the clinical picture was confounded with an asthmatic crisis. CTA confirmed the diagnosis and treatment by endovascular embolization was successful.

Precision diagnosis and therapy of a case of brain abscesses associated with asymptomatic pulmonary arteriovenous fistulas.

BACKGROUND: Brain abscesses, a severe infectious disease of the CNS, are usually caused by a variety of different pathogens, which include Streptococcus intermedius (S. intermedius). Pulmonary arteriovenous fistulas (PAVFs), characterized by abnormal direct communication between pulmonary artery and vein, are a rare underlying cause of brain abscesses. CASE PRESENTATION: The patient was a previous healthy 55-year-old man who presented with 5 days of headache and fever. Cerebral magnetic resonance imaging (MRI) suggested a brain abscess. Thoracic CT scan and angiography demonstrated PAVFs. Aiding by metagenomic next-generation sequencing (mNGS) of the cerebrospinal fluid (CSF) sample which identified S. intermedius as the causative pathogen, the patient was switched to the single therapy of large dose of penicillin G and was cured precisely and economically. CONCLUSIONS: It is an alternative way to perform mNGS to identify causative pathogens in patients with brain abscesses especially when the results of traditional bacterial culture were negative. Further thoracic CT or pulmonary angiography should also be undertaken to rule out PAVFs as the potential cause of brain abscess if the patient without any known premorbid history.

Fístulas arteriovenosas pulmonares en un paciente pediátrico: un reporte de caso / Pulmonary arteriovenous fistulas in a pediatric patient: a case report

Las fístulas arteriovenosas pulmonares son malformaciones congénitas dadas por la comunicación directa anómala entre arterias y venas, con una incidencia mundial de 2-3 : 100 000 habitantes. La presentación es, en general, única, asintomática, y aparecen en forma incidental como hallazgo imagenológico en la adultez, y su tratamiento de elección es la embolización endovascular.Se describe la inusual presentación clínica en una paciente de 10 años, que ingresó por disnea, tos, cianosis central y cefalea. Se encontró hipoxemia persistente, hipocratismo digital, nódulos parahiliares pulmonares, gases arteriales con gradiente alvéolo-arterial aumentado. La tomografía axial computarizada de tórax de alta resolución confirmó la presencia de una malformación arteriovenosa pulmonar en la región parahiliar derecha, la cual no se asociaba con la enfermedad de Rendu-Osler-Weber. La paciente fue tratada con embolización endovascular transcutánea. Tras 1,5 años de seguimiento, no hubo recaídas. Son pocos los casos reportados de estas fístulas en la edad pediátrica

Pulmonary arteriovenous fistulas are congenital malformations due to anomalous direct communication between arteries and veins; the incidence is 2-3 : 100,000 inhabitants. This condition is usually asymptomatic and incidentally appearing in adult imaging findings. Transcutaneous endovascular embolization is the technique of choice for treatment. The unusual presentation in a 10-year-old patient is described; she was presented to the Emergency Department with dyspnea, cough, central cyanosis and headache. The examination revealed persistent hypoxemia and digital clubbing; chest X-ray with images suggestive of parahilar nodules, arterial blood gases with increased alveolar arterial gradient. The high resolution computed tomography of the thorax revealed pulmonary arteriovenous malformation in the right parahilar region not associated with Rendu-Osler-Weber disease. The patient was treated with transcutaneous endovascular embolization, and after a year and a half of follow-up there were no relapses. There are few reported cases of pulmonary arteriovenous fistulas in the pediatric age.

[Pulmonary arteriovenous fistulas in a pediatric patient: a case report]. / Fístulas arteriovenosas pulmonares en un paciente pediátrico: un reporte de caso.

Pulmonary arteriovenous fistulas are congenital malformations due to anomalous direct communication between arteries and veins; the incidence is 2-3 : 100,000 inhabitants. This condition is usually asymptomatic and incidentally appearing in adult imaging findings. Transcutaneous endovascular embolization is the technique of choice for treatment. The unusual presentation in a 10-year-old patient is described; she was presented to the Emergency Department with dyspnea, cough, central cyanosis and digital clubbing; chest X-ray with images suggestive of parahilar nodules, arterial blood gases with increased alveolar arterial gradient. The high resolution computed tomography of the thorax revealed pulmonary arteriovenous malformation in the right parahilar region not associated with Rendu-Osler- Weber disease. The patient was treated with transcutaneous endovascular embolization, and after a year and a half of follow-up there were no relapses. There are few reported cases of pulmonary arteriovenous fistulas in the pediatric age.

Las fístulas arteriovenosas pulmonares son malformaciones congénitas dadas por la comunicación directa anómala entre arterias y venas, con una incidencia mundial de 2-3 : 100 000 habitantes. La presentación es, en general, única, asintomática, y aparecen en forma incidental como hallazgo imagenológico en la adultez, y su tratamiento de elección es la embolización endovascular. Se describe la inusual presentación clínica en una paciente de 10 años, que ingresó por disnea, tos, cianosis central y cefalea. Se encontró hipoxemia persistente, hipocratismo digital, nódulos parahiliares pulmonares, gases arteriales con gradiente alvéolo-arterial aumentado. La tomografía axial computarizada de tórax de alta resolución confirmó la presencia de una malformación arteriovenosa pulmonar en la región parahiliar derecha, la cual no se asociaba con la enfermedad de Rendu-Osler-Weber. La paciente fue tratada con embolización endovascular transcutánea. Tras 1,5 años de seguimiento, no hubo recaídas. Son pocos los casos reportados de estas fístulas en la edad pediátrica.

Efficacy of bubble contrast echocardiography in detecting pulmonary arteriovenous fistulas in children with univentricular heart after total cavopulmonary connection.

BACKGROUND: Development of pulmonary arteriovenous fistulas in patients with cavopulmonary anastomosis may result in a significant morbidity. Although the use of bubble contrast echocardiography with selective injection into both the branch pulmonary arteries in identifying pulmonary arteriovenous fistulas has been increasing, the actual efficacy of this diagnostic modality has not been properly evaluated. Thus, this study aimed to assess the efficacy of bubble contrast echocardiography in detecting pulmonary arteriovenous fistulas in children with total cavopulmonary connection. METHODS: A total of 140 patients were included. All patients underwent cardiac catheterisation. Bubble contrast echocardiographic studies were performed by injecting agitated saline solution into the branch pulmonary arteries. Transthoracic echocardiograms that use an apical view were conducted to assess the appearance of bubble contrast in the systemic ventricles. Then, the contrast echocardiogram results and other cardiac parameters were compared. RESULTS: No correlation was found between contrast echocardiogram grade and other cardiac parameters, such as pulmonary capillary wedge saturation and pulmonary artery resistance. Moreover, only 13 patients had negative results on both the right and left contrast echocardiograms, and 127 of the 140 patients had positive results on contrast echocardiograms even though they had normal pulmonary capillary wedge saturation. Results showed that bubble contrast echocardiography was a highly sensitive method and was likely to obtain false-positive results. CONCLUSIONS: Bubble contrast echocardiography might be highly false positive in detecting pulmonary arteriovenous fistulas in patients with cavopulmonary anastomosis. We have to consider how we make use of this method. Further standardisation of techniques is required.

Embolization using hydrogel-coated coils for pulmonary arteriovenous malformations.

PURPOSE: To prospectively evaluate the efficacy and safety of embolization using hydrogel-coated coils for the treatment of pulmonary arteriovenous malformations (PAVMs). MATERIALS AND METHODS: The outcomes of 21 PAVMs in 19 patients (3 men and 16 women; mean age, 58.8±15.2 [SD] years; age range 14-78 years) treated by venous sac embolization (VSE) with additional feeding artery embolization were prospectively evaluated. For VSE, using one or more 0.018-inch hydrogel-coated coils was mandatory. Recanalization and/or reperfusion were evaluated by pulmonary arteriography 1 year after embolization. RESULTS: The mean feeding artery and venous sac sizes were 4.0mm and 8.5mm, respectively. Embolization was successfully completed in 20/21 PAVMs, yielding a technical success rate of 95%. The feeding artery was also embolized in 17/20 successful PAVMs (85%). A technical failure occurred in one PAVM, where embolization was abandoned because of migration of one bare coil to the left ventricle. The mean numbers of hydrogel-coated coils and bare platinum detachable coils used for VSE were 3.3±2.1 (SD) (range, 1-8) and 4.4±3.9 (SD) (range, 1-17), respectively. The mean percentages of hydrogel-coated coils in number, length, and estimated volume were 42.9%, 33.3%, and 72.7% respectively. One patient with one PAVM was lost to follow-up after 3 months. Neither recanalization nor reperfusion was noted in the remaining 19 PAVMs (success rate, 19/19 [100%]). One grade 4 (coil migration) adverse event occurred, and it was treated without any sequelae. CONCLUSION: VSE using hydrogel-coated coils with additional feeding artery embolization is a safe and effective treatment for PAVM.

Long-Term Single-Center Retrospective Follow-Up After Embolization of Pulmonary Arteriovenous Malformations Treated Over a 20-year Period: Frequency of Re-canalization with Various Embolization Materials and Clinical Outcome.

PURPOSE: The present study is a register-based observational study of an unselected consecutive patient cohort with pulmonary arteriovenous malformations (PAVMs) from a single national hereditary hemorrhagic telangiectasia and PAVM embolization center. The aim was to investigate the frequency of re-embolizations and the clinical outcome after embolization with the use of different embolization materials further, to define which PAVM morphology and size of feeding arteries that most often were re-embolized, and to estimate the clinical outcome of the patients including those that were re-embolized. METHODS: The population was included from 1996 until 2016 and was made up of a total of 136 patients with 322 PAVMs. Median follow-up was 38.3 (0.3-241 months). RESULTS: The re-embolization rate was 9.3%. None of the PAVMs treated with detachable silicone balloons were re-embolized, while 4.5% treated with vascular plugs and 11.7% treated with coils were re-embolized (p=0.07). In total, 16/74 complex PAVMs were re-embolized compared with 14/248 simple PAVMs. In big-sized feeding arteries ≥ 6mm, 16/112 were re-embolized compared with 14/210 with smaller-sized feeding arteries. Out of the 30 re-embolized PAVMs, 23 resulted in a successful clinical outcome. CONCLUSIONS: Our results suggest that standard coils probably should not be the first choice for embolization of PAVMs, and vascular plug alone or in combination with coils might be a better primary option for embolization in these patients. LEVEL OF EVIDENCE: Level 3A, non-randomized case controlled cohort/follow-up study.

Fontan operation with bilateral conduits for the treatment of pulmonary arteriovenous fistulas in a patient with polysplenia after reconstruction of a non-confluent pulmonary artery.

We describe a case involving a successful Fontan procedure for the treatment of pulmonary arteriovenous fistulas in a patient with polysplenia. The patient was diagnosed with bilateral superior vena cavae, interrupted inferior vena cava with azygos connection, wide separate hepatic veins, and central pulmonary artery stenosis following repair of a non-confluent pulmonary artery. Bilateral extracardiac conduits were used to connect each hepatic vein to the pulmonary artery, opposite each superior vena cava. Clinical improvement in the pulmonary arteriovenous fistulas was observed within 4 months after surgery.

A case of prenatally diagnosed extrapulmonary arteriovenous malformation associated with a complex heart defect.

Pulmonary arteriovenous malformations are rare vascular anomalies of the lung, only a few cases of which have been diagnosed prenatally. The diagnostic clue for prenatal diagnosis was cardiomegaly with a particularly enlarged left atrium. All previous cases of pulmonary arteriovenous malformations diagnosed prenatally have been reported as an isolated anomaly or in association with simple heart defects. We here describe the first case of a pulmonary arteriovenous malformation with a complex heart defect that was diagnosed prenatally at 21.0 weeks of gestation and confirmed by postmortem autopsy.

A case of prenatally diagnosed extrapulmonary arteriovenous malformation associated with a complex heart defect

Pulmonary arteriovenous malformations are rare vascular anomalies of the lung, only a few cases of which have been diagnosed prenatally. The diagnostic clue for prenatal diagnosis was cardiomegaly with a particularly enlarged left atrium. All previous cases of pulmonary arteriovenous malformations diagnosed prenatally have been reported as an isolated anomaly or in association with simple heart defects. We here describe the first case of a pulmonary arteriovenous malformation with a complex heart defect that was diagnosed prenatally at 21.0 weeks of gestation and confirmed by postmortem autopsy.