Background

Patients undergoing percutaneous recanalization of chronically occluded superficial femoral arteries were studied to determine which factors correlated with 1-year patency. Immediate change in ankle:brachial index (ABI), length of occlusion, tibial run-off, and the performance of supplemental catheter atherectomy were evaluated.

Methods

Eligible patients had at least one patient tibial run-off vessel and the absence of limb-threatening ischemia. Recanalization was performed via passage of a guidewire followed by balloon angioplasty. Tibial run-off was scored based on a modification of the angiogram scoring system of the Society for Vascular Surgery and the International Society for Cardiovascular Surgery. Supplemental transcutaneous extraction catheter atherectomy was randomly assigned to a sub-group of patients after initial experience with the recanalization technique. Clinical follow-up was employed to determine patency.

Results

Forty-two of 57 attempts (74%) at recanalization were immediately successful. Overall 1-year patency was 40% in 40 limbs that could be followed. In limbs with balloon angioplasty alone (n = 23), patency was 43% compared with 35% in those having supplemental atherectomy. Tibial run-off did not vary significantly between patent and occluded groups. When ABI increased by 0.3 or more, patency was 56% compared with 26% when the ABI increase was less than or equal to 0.1 (P = 0.13). Occlusion length averaged 18.1 +/- 10.6 cm for all limbs and did not vary significantly between early successes and failures. Limbs with short occlusions (less than or equal to 5 cm, n = 8) had 63% patency compared with 38% patency for limbs with long occlusions (greater than 25 cm, n = 16), but the difference was not significant by analysis of variance.

Conclusions

An initial change in ABI was most predictive for patency, whereas no correlation with tibial run-off was demonstrated. Atherectomy did not increase patency. Short occlusions were more likely to remain patent than long ones, but overall patency was lower than described in other series.

Objectives

The purpose of this study was to test the hypothesis that in occlusions of the superficial femoral artery, removal of atherosclerotic plaque would result in a higher long-term patency rate compared to balloon dilatation alone. A secondary hypothesis was that long term patency would be proportional to the amount of plaque removed.

Methods

A randomized controlled study of patients with occluded superficial femoral arteries was performed comparing balloon dilatation alone versus a 2.7 mm or a larger (4.0 mm or 4.7 mm) transcutaneous extraction catheter (TEC) atherectomy device followed by balloon dilatation. The effect of these devices on plaque area was assessed directly by intravascular ultrasound imaging.

Results

The mean occlusion length was 19.4 cm +/- 11.7 cm. The mean lumen area increased from 4.7 mm2 to 15.1 mm2, primarily due to balloon dilatation, but the mean atheroma area of 19.8 mm2 did not change with either size of TEC device. Although the initial procedure success rate was high (79%), the 6 month patency was only 45%. There was no difference in 6 month patency between the 3 groups.

Conclusions

The data indicate that the TEC atherectomy devices do not remove a significant amount of atherosclerotic plaque in occluded superficial femoral arteries. The 6 month patency is no different with these atherectomy devices than with balloon dilatation alone. The larger (4.0 mm or 4.7 mm) TEC device does not remove any more tissue than the smaller (2.7 mm) device. The use of intravascular ultrasound to quantitate the effects of this atherectomy device provides important insights into the mechanism of action and lack of efficacy of the TEC atherectomy catheter.

A randomized clinical trial was performed to test the hypothesis that a laser-heated probe is superior to standard techniques to reopen occluded femoral arteries. Twenty patients were treated with a standard guidewire and balloon dilation method. In a second group of 20 patients, the laser probe was initially used as a nonheated mechanical device. If the probe was unsuccessful in mechanically reopening the artery, an Argon laser was activated to heat the probe. The mean length of occlusion was 15.9 +/- 10.3 cm. The success rate for the laser probe was 15 of 20 (75%), which was not significantly different from the standard method, 19 of 20 (95%). Most of the success in the laser-probe group was due to the probe's mechanical properties. The laser probe was successful as a cold, mechanical device in 13 of 15 (87%) arteries. It was necessary to heat the probe in 5 patients. When heated, the laser probe assisted recanalization in 2 but perforated the artery in 3 cases. The results of this randomized trial do not support the hypotheses behind the use of the thermal laser probe. The laser probe functions primarily as a mechanical device. The thermal activation does not significantly improve the success rate without increasing the risk of perforation. This small additional benefit does not justify the large cost of current thermal laser devices. This controlled study also demonstrates a higher success rate in long occlusions than previous reports of mechanical balloon recanalization. This is due to a combination approach of retrograde and anterograde probing of the occluded segment.