Biplane color flow duplex intravenous intravascular ultrasound for arterial visualization

The Use of Vascular Stents in the Treatment of Iliac Artery Occlusion

To evaluate our experience of selective iliac artery stenting for total occlusions, a prospective observational study of 25 patients with an occluded iliac artery was designed to run from January 1996-May 1997. Exclusion criteria were an occlusion extended to the femoral artery, claudication Grade III or IV, according to the standards for reports dealing with lower extremity ischemia, and vascular (bypass) surgery in the past. Complete recanalization and selective stent placement was possible in all patients. No complications occurred. In one patient re-stenosis happened inside the stent after a year. Percutaneous reintervention was performed with success. The mean ankle-brachial pressure increased from 0.46 before the procedure to 0.95 after the procedure. After two years of follow-up, the mean ankle-brachial pressure is 0.93. The clinical stage improved by at least one grade to Grade 0 (Rutherford classification). The overall probability of patency for occluded iliac arteries in this study was 95% after two years. Recanalization, followed by percutaneous transluminal angioplasty (PTA) in the treatment of iliac artery occlusions, is our first choice of intervention, considering the absence of complication and satisfactory patency rates in patients with claudication Grade I or II.

Transvascular Imaging: Feasibility Study Using a Vector Phased Array Ultrasound Catheter

BACKGROUND: Transvascular imaging is defined as the acquisition of anatomic and functional information of structures lying beyond the confines of a vascular conduit within which the imaging device resides. Interrogating structures surrounding the vascular conduit is the subject of this feasibility study using a novel underblood, phased array ultrasound-tipped catheter. METHODS: An intravascular catheter (10-F, 3.2-mm-diameter, four-way articulation) tipped with a 5.5- to 10-MHz frequency agile, vector phased array transducer with full Doppler capability (Sequoia, Acuson) was used. The imaging transducer has a wide range of tissue penetration (2 mm to >10 cm from the lens). The catheter was introduced via an 11-Fr femoral venous sheath into the inferior and superior vena cavae and right heart chambers. As the catheter was advanced, attention was directed to visualization of structures surrounding the vessel in which the catheter resided. RESULTS: From the cavae and femoral vein the thoracic, abdominal and femoral arteries could be easily imaged. Anatomy that was visualized included the liver, hepatic veins, gallbladder, and mesenteric vessels. Normal and pathological anatomy and Doppler physiology could be readily appreciated. Doppler (i.e., pulsed- and continuous-wave, color flow, and tissue Doppler) fostered unique transvascular physiological hemodynamic and flow assessment. CONCLUSION: Transvascular imaging is feasible in human subjects using this 10-Fr catheter tipped with a 5.5- to 10-MHz vector phased array transducer. Intravascular navigation to a desired location within the body and the performance of diagnostic or therapeutic procedures at a remote site under direct ultrasound visualization are possible. Full Doppler capability extends the concept of transvascular hemodynamic and physiological assessment.