PERIPHERAL TRANSLUMINAL ANGIOPLASTY UNDER ULTRASOUND GUIDANCE - INITIAL CLINICAL-EXPERIENCE AND PREVALENCE OF LOWER-LIMB LESIONS AMENABLE TO ULTRASOUND-GUIDED ANGIOPLASTY

Purpose: Currently, endovascular techniques require monitoring by radi ographic imaging for accurate catheter placement. The aim of this stud y was first to determine the feasibility of angioplasty under ultrasou nd guidance using a special catheter system. Based on this outcome, th e second goal was to investigate the prevalence of lesions amenable to ultrasound-guided angioplasty. Methods: A balloon catheter system (Ec homark) has been developed, which allows accurate catheter guidance by ultrasound imaging. An ultrasound-sensitive piezoelectric sensor posi tioned in the middle of the balloon portion of the angioplasty cathete r is interfaced to an external duplex scanner via the catheter system. The exact position of the balloon relative to the transducer is calcu lated and reproduced on the screen of the duplex scanner to guide ball oon positioning. in the feasibility assessment of the procedure, 16 pa tients with disabling claudication and rest pain were selected for bal loon angioplasty under ultrasound guidance based on arteriographic and hemodynamic lesion criteria of > 50% stenosis with a peak systolic ve locity ratio > 2.5 in a lesion < 4 cm long that could be imaged by dup lex ultrasonography. A fall in the peak systolic velocity ratio below 2.0 was selected for a procedural endpoint corresponding to < 30% resi dual stenosis on the completion angiogram. In the second part of the s tudy, the prevalence of stenoses amenable to ultrasound-guided angiopl asty was studied in 80 patients presenting with symptoms of peripheral arterial disease. Results: In the feasibility study, 20 stenoses (5 c ommon iliac, 6 external iliac, and 8 superficial femoral arteries and 1 graft) meeting the inclusion criteria were subjected to ultrasound-g uided angioplasty with confirmation by completion angiography. The pro cedure was possible in 18 (90%) of the 20 stenoses. The two failures o ccurred in iliac arteries that could not be imaged by duplex scanning due to obesity, bower gas, and/or vessel wall calcification. In one ca se, the peak systolic velocity ratio exceeded 2.5 despite a satisfacto ry control arteriogram; redilation was performed, and the ratio fell b elow 2.0. In the second part of the study, 21 (26.2%) of the 80 patien ts had 29 stenoses that were amenable to angioplasty according to angi ographic criteria (> 50% stenosis and < 4 cm length). All these stenos es were evaluated with duplex scanning to determine their suitability for angioplasty under ultrasound guidance. Twenty-three (79%) of the 2 9 lesions selected for angioplasty were well visualized by duplex, and angioplasty would have been possible based on our initial clinical ex perience. Conclusions: Angioplasty under ultrasound control is a feasi ble technique for peripheral lesions. Ultrasound allows monitoring of both anatomical and hemodynamic parameters during angioplasty and thus provides a procedural endpoint that correlates to the control angiogr am. A large proportion (79%) of stenoses deemed suitable for angioplas ty can be well visualized by ultrasound, but obesity, vessel wall calc ification, and bowel gas may limit the ability to obtain a satisfactor y ultrasound image. Ultrasound-guided angioplasty is a potentially use ful procedure that warrants further investigation.