Left internal mammary artery to innominate vein fistula complicating pacemaker insertion. Treatment with endovascular transarterial coil embolization.

Arteriovenous fistula (AVF) is rarely encountered as a complication of pacemaker insertion. Percutaneous angiographic therapy of such iatrogenic fistulas can be both safe and effective, leading to important reductions in costs. A 60-year-old woman was admitted to the hospital four weeks after left subclavian pacemaker insertion complaining of signs of congestive heart failure. A loud continuous machinery bruit was heard over the left upper chest. An arteriogram revealed a false aneurysm from the LIMA, 6 mm in-diameter, with formation of an AVF between the LIMA and the left innominate vein. Embolization of the LIMA was carried out using seven Platinum coils at the level of the AVF and the false aneurysm was embolized with 3 controlled-release IDC coils. The complete occlusion of the fistula was achieved and the distal LIMA persisted patent due to the opening of collateral vessels from the intercostal arteries. AVF between the subclavian artery or its branches and the subclavian or innominate veins have been reported to be congenital, traumatic and iatrogenic (associated to central venous access to hemodynamic monitoring, dialysis, and very infrequently to pacemaker insertion) but the internal mammary arteries are only rarely involved. The course of AVF is undefined, but generally, surgical or percutaneous embolization is warranted because of the potential appearance of a great number of complications. Surgical repair is associated with significant morbidity and mortality. Whenever possible, percutaneous nonsurgical occlusion of the AVF with coil embolization is the procedure of choice, because of its high success rate and low morbidity.