The mechanism of peripheral recanalization by laser-assisted thermal angioplasty: confirmation by intravascular sonography.

Downloaded from www.ajronline.org by Univ of California Irvine on 10/07/15 from IP address 128.200.102.37. Copyright ARRS. For personal use only; all rights reserved Case The Mechanism Assisted of Peripheral Thermal Intravascular Recanalization Angioplasty: Cres P. Miranda,1 Larry Deutsch,2 The mechanism of recanalization during laser-assisted an- gioplasty in the treatment of obstructive atherosclerotic vas- cular disease has been controversial. Initial reports claimed that the laser-heated metal-tipped probe ablated atheroma as the hot tip “sought the lumen” and progressed down the artery as it created a new lumen in the central portion of the plaque [1 -3]. In distinction to the initial animal and clinical studies, an in vitro study of the mechanism of recanalization with laser-assisted thermal angioplasty found it to be a pre- dominantly mechanical process in which the laser probe was deflected by the hard, fibrocalcific plaque away from the true lumen and followed a dissection plane between the intimal plaque and the arterial media [4]. However, in human clinical trials, it is difficult to prove the exact pathway of the laser probe by using angiography or angioscopy. Recent work has documented the feasibility of imaging arteries in cross-section with a miniaturized catheter-mounted transducer that generates arterial images from inside the artery lumen [5, 6]. This report documents that the information obtained from the intravascular sonographic de- vice in vivo is consistent with the hypothesis derived from our in vitro study for the mechanism of recanalization by the laser probe. Received 1 Division 2 Division Confirmation Jim Griffith,3 Case 4 The Beckman AJR 155:1100-1102, Inc., Santa Laser by Jim Gessert,3 (SFA) man with claudication occlusions Institute, Irvine, the 100 © American Berns,4 at the had bilateral superficial bifurcation with the common femoral femoral right SFA was 20 cm, and the left SFA was occluded 23 cm. The right femoral artery was recanalized in a retrograde fashion from a puncture in the popliteal fossa. A 1 .5-mm-diameter laser probe (Model PLA-plus, advanced under and an 8-French Trimedyne fluoroscopic angioplasty Inc., Santa Ana, CA) was inserted control guiding through catheter. and an introducing sheath The laser probe was used as a cold mechanical device without turning on the argon laser. The laser probe was advanced by using intermittent forward pressure to puncture the occlusive atheroma. The course of the laser probe was followed under fluoroscopic control until it advanced to the proximal end of the SFA and reentered the lumen of the common femoral artery. The laser probe was then removed, and a guidewire was inserted through a 7-French diagnostic catheter, which was used in a rotary maneuver to enlarge the communication between the SFA and the common femoral artery. The 20-MHz sonographic catheter (Interlherapy, Inc. , Costa Mesa, CA) was advanced in the new channel to the level of the common Figure 1 A shows the level of the distal Roentgen the intravascular SFA before femoral artery. sonogram the sonographic that was obtained catheter , Orange, CA 92668. Address reprint requests to J. M. Tobis. CA 92668. CA 92717. 1990 0361-803X/90/1 Michael artery. Both popliteal arteries were reconstituted, and distal runoff was good. The patient refused surgical intervention but was willing to undergo percutaneous angioplasty. The length of the occlusion of Ana, CA 92705. November Avi Bergman,3 Report A 73-year-old artery February 1 2, 1 990; accepted after revision April 27, 1990. of Cardiology, University of Califomia, Irvine, Medical Center, P.O. Box 14091 of Radiologic Sciences, University of Califomia, Irvine, Medical Center, Orange, InterTherapy by Laser- Sonography Jonathan M. Tobis,1 and Walter Henry1 sonographic Report Ray Society entered at