Reperfusion of Pulmonary Arteriovenous Malformations After Embolotherapy

AVMs are abnormal collections of blood vessels which can occur in any part of the body including the lungs. These blood vessels are weakened and can rupture anytime causing bleeding which can be massive, leading to life-threatening conditions. Pulmonary AVMs occur in about 40% of patients with HHT. Each patient may have an average of 5 AVMs .Rupture of the AVM can lead to massive bleeding in the lung, stroke and infection of the brain. In order to prevent these complications, patients with HHT are routinely examined for pulmonary AVMs and treatment with embolization is recommended. AVMs have a main blood vessel or artery supplying blood to the collection of blood vessels. The way to treat AVMs is cut off their blood supply through a process called embolization. Embolization is a standard medical procedure which is done to stop or prevent hemorrhage (bleeding) from an AVM. It involves blocking the artery that supplies blood to the AVM by inserting a foreign body, into the blood vessel supplying blood to the AVM. Standard devices used for embolization include coils (made of stainless steel or platinum). These devices usually have a good success rate for blocking the artery that supplies blood to the AVM. However, a few AVMs that are embolized by standard devices may reopen over time. This is called reperfusion and will require repeat embolization procedures. For embolization of pulmonary AVMs at St. Michael's Hospital, the Nester coil is used. In this study, we would like to compare the Nester coil with a new coil device called the Interlock Fibered IDC Occlusion System. Both coils are approved for use in Canada, however the cost of the IDC coil limits its use at this hospital. Compared to the Nester coil, the IDC coils are made so that they can be removed or repositioned if they are not placed correctly. The coil also allows tighter packing which helps prevent reperfusion. This study will compare the success rate of embolization between the Interlock™ Fibered