September 2002 / Volume 47 / Number 9 / Page 998
Huge Pulmonary Arteriovenous Fistula: Diagnosis and Treatment and an Unusual Complication of Embolization
We report the case of a 42-year-old woman with Rendu-Osler-Weber syndrome (hereditary hemorrhagic telangiectasia) and a huge pulmonary arteriovenous fistula that involved the entire right middle lobe. She had a history of dyspnea and intermittent atrial flutter for 6 months. A chest radiograph showed a discrete shadowing of the middle part of the right lung. Arteriovenous fistula was suspected based on the echocardiographic finding of immediate bubble detection in the left atrium on introducing echocardiographic contrast medium into the venous system. Atrial shunt was excluded. Angiography revealed a huge pulmonary arteriovenous fistula in the entire middle lobe of the right lung. A trial of interventional embolization was performed, but the size of the fistula made it impossible to achieve complete closure of all segmental fistulas. Furthermore, the patient complained of unusual, severe chest pain after implantation of the first coil, so that the coil had to be removed. Therefore the patient underwent surgical resection of the entire right middle lobe and the upper part of the right lower lobe. Anatomy was clearly delineated and all connecting vessels were suture-closed, but both lungs showed diffuse microscopic superficial pulmonary arteriovenous fistulas, which were too small to be detected by angiography and which were also partly closed. The postoperative course was uneventful: the patient recovered completely, she no longer had shortness of breath, and blood gas analysis showed normal PaO2. It is not clear whether the patient's improved physical performance will last, because the development of diffuse microscopic arteriovenous fistulas bilaterally in the lungs is not predictable. Therefore close follow-up is necessary and in the case of recurrence (ie, enlargement of the existing small fistulas), early interventional embolization should be performed.
Key words: pulmonary arteriovenous fistula, transcatheter coil embolization, surgical resection, pneumonectomy, Rendu-Osler-Weber syndrome, hereditary hemorrhagic telangiectasia, embolization.
[Respir Care 2002;47(9):998–1001]
Pulmonary arteriovenous (AV) fistulas are vascular, mainly congenital, malformations, which are associated in 60% of cases with Rendu-Osler-Weber syndrome (hereditary hemorrhagic telangiectasia). These lesions are thought to represent persistent primitive AV communications from pulmonary buds that fail to mature into capillary beds and thereby function as persistent right-to-left shunts. Multiple lesions are found in 33-50% of patients and can be bilateral in up to 20%.
Congenital pulmonary AV fistulas cause intrapulmonary right-to-left-shunt. Because of the amount of shunt volume, patients clinically present with dyspnea, cyanosis, clubbing, or erythrocytosis. Ventricular failure may develop. Further possible complications are thrombus formation and paradoxical embolism with systemic infarction. Fistulas can be effectively treated by either surgical resection or transcatheter coil embolization.
We report a patient with a huge pulmonary AV fistula—to our knowledge the biggest ever reported—who presented with typical clinical signs. The favored procedure of coil occlusion was not possible because of the size of the AV malformation, which had multiple feeding arteries, and which caused unusual severe chest pains after implantation of the first coil. The coil had to be removed. Surgical resection was successful.