DUPLEX AND COLOR DOPPLER SONOGRAPHY OF COMPLICATIONS AFTER PERCUTANEOUS INTERVENTIONAL VASCULAR PROCEDURES

Duplex and color Doppler sonography have proved to be excellent noninv asive modalities for evaluating complications of percutaneous interven tional vascular procedures. Complications including hematoma, pseudoan eurysm, arteriovenous fistula, thrombosis, stenosis, and vessel occlus ion are routinely diagnosed with Doppler sonography. Hematomas exhibit variable echogenicity and internal complexity but never demonstrate i nternal blood flow. A pseudoaneurysm is a contained extravasation of b lood that, unlike a hematoma, maintains a patent vascular connection w ith the injured vessel. Puncture-related arteriovenous fistulas are fa lse vascular channels between an adjacent artery and vein that demonst rate low-resistance arterial signal, high-velocity venous outflow and variable flow patterns within themselves. Narrowing in a stent demonst rates high-velocity turbulent flow with conventional Doppler and color aliasing with color Doppler techniques. Thrombus can be seen directly as a mural-based or luminal defect; however, it is often alterations in color flow dynamics, waveform characteristics, and flow velocities that permit conclusive diagnosis. Early experience in evaluation of st ent stenosis in patients with transjugular intrahepatic portosystemic shunts suggests that low-velocity shunt flow indicates stenosis, likel y related to the presence of low-resistance collateral pathways. Famil iarity with both the interventional procedures and their possible comp lications facilitates prompt diagnosis and treatment.