ARTERIAL EMBOLOTHERAPY Coordinator: Steven Meranze, MD, FSIR FACULTY John Borsa, MD Peter Bream, Jr., MD Todd Kooy, MD Jeet Sandhu, MD Richard Shlansky-Goldberg, MD, FSIR LeAnn Stokes, MD Arterial embolotherapy, or embolization, is the selective endovascular occlusion of an artery or arterial bed. Successful embolization requires a thorough knowledge of arterial anatomy, embolic agents and delivery systems, as well as practical experience with the use of different types of embolic materials and catheters. The embolic agent of choice depends on whether temporary or permanent occlusion is desired and whether proximal or distal occlusion is required (see table). Material Duration Location Gelfoam Temporary Proximal to mid Avitene Temporary Distal Ethibloc gel Temporary Proximal, mid or distal Occlusion balloon Temporary Proximal Particles (PVA, Ivalon) Permanent Mid to distal Spherical embolics (Embospheres, Contour SE PVA, Bead Block Permanent Mid to distal Coils Permanent Proximal, mid or distal Detachable balloon Permanent Proximal Sclerosants (sodium tetradecyl sulfate, sodium morrhuate, alcohol Permanent Proximal, mid or distal Thrombin Permanent Proximal, mid or distal Glue Permanent Proximal, mid or distal Onyx Permanent Proximal, mid or distal Amplatzer Permanent Proximal to mid Temporary (Reabsorbable) Materials Gelfoam (absorbable gelatin sponge) Gelfoam is one of the most widely used embolic agents and was previously available in both powder and sheet forms. Gelfoam powder measures 40-60 microns in diameter and produces a very peripheral occlusion. Because of this very distal level of occlusion, ischemic complications or frank infraction may occur with gelfoam powder, especially when non target embolization of normal tissue occurs. As of this writing, powdered gelfoam is no longer available and we will concentrate on the available sheet form. The sheets can be divided into pledgets and strips of various sizes. Small pledgets measuring 1-2 mm are utilized frequently. The strips are often compressed into the form of a cigar or torpedo and loaded in the nozzle of a 1 cc syringe. The gelfoam is then injected through the catheter using the hydrostatic force generated from the small syringe. A gelfoam slurry can also be made by shaving small pieces of gelfoam off of the sheet and suspending them in a mixture of contrast and saline either in a bowl or through a three-way stop cock between two syringes. This material can then be injected through the catheter. Gelfoam provides a temporary occlusion lasting approximately 3-6 weeks. In addition to producing mechanical occlusion of the vessel, it acts as a matrix for further thrombus formation. Inflammation of the