The LACI Trial: 6-Month Results
The results of the Laser Angioplasty for Critical Limb Ischemia (LACI) trial may validate the resurrection of laser technology in treating PVD.
By Alicia Fagan
To view the figures and tables related to this article, please refer to the print version of our October issue, page 17.
John R. Laird, Jr, MD, presented the results of the LACI trial at the recent TCT meeting in Washington, DC. The following is adapted from his presentation.
In contrast to the thermal, continous-wave lasers abandoned in the early 1990s, the unique properties of the excimer laser have resulted in excellent clinical outcomes for the treatment of critical limb ischemia (CLI), as supported by the Laser Angioplasty for Critical Limb Ischemia (LACI) Trial.
The prognosis for patients with CLI is poor. Within 3 months of presentation, 9% of patients will die, 1% will have a myocardial infarction, 1% will suffer from stroke, 12% will have an amputation, and 18% will have persistent CLI. CLI is a marker for premature death, with mortality rates at 21% at 1 year from diagnosis and 31.6% at 2 years. Historical results for PTA reflect simple lesion subsets (TASC A and B lesions) and range in limb salvage rates from 25% to 85%, depending on disease severity and lesion location. These results led to the initiation of the LACI trial, a prospective, multicenter trial to evaluate the effectiveness of excimer laser angioplasty with adjunctive PTA and optional stenting.
The LACI trial enrolled 145 patients with 155 critically ischemic limbs and 423 lesions at 15 sites in the US and Germany. Patient and limb characteristics were typical of individuals with systemic vascular disease, with a high incidence of diabetes, hypertension, and cardiac disease (Table 1). To be enrolled into the trial, patients had to be considered poor or nonsurgical candidates (Table 2).
LACI patients presented with severe and diffuse vascular disease typical of CLI. Of the 423 lesions, 41% were in the SFA, 15% were in the popliteal artery, and 41% were in infrapopliteal arteries (Figure 1). Furthermore, 70% of the patients had a combination of stenoses and occlusions, which complicated treatment (Figure 2).
Use of the excimer laser led to an increase in the ability to treat this very complex patient population. Despite a failed guidewire crossing in 8% of the cases, laser treatment was delivered in 99% of the cases, with adjunctive balloon angioplasty successfully performed in 96% (Table 3).
In-hospital serious adverse events were extremely low in this fragile patient group. No deaths or surgical interventions occurred as a result of the procedure, and no patient experienced acute limb ischemia after intervention. Reintervention procedures to reopen stenosed or occluded lesions were expected given the complexity of the disease, and were given to 16% of patients during follow-up. Serious adverse events during the 6-month enrollment period included 10% mortality, almost exclusively from cardiac causes; no patient died within 30 days of the index procedure. Major amputation was required in 11 cases, whereas four limbs underwent surgical revascularization (Table 4).
At 6 months, 34% of limbs survived with persistent CLI. However, in poor surgical candidates with a high probability of amputation, LACI resulted in a limb salvage rate of 92% in survivors at 6 months (Table 5). Only 2% of LACI patients required surgical revascularization during follow-up. Furthermore, of surviving legs, 69% improved in Rutherford category, 27% remained stable, and only 4% declined in Rutherford category (Table 5).
Unique to all studies on CLI, the LACI trial incorporated digital photography (morphography) for every patient enrolled at inclusion, prior to treatment, to document and map the extent of lower limb or pedal ulceration(s). Repeat morphography was done at the 3- and 6-month follow-up visits using the same photographic projections obtained at inclusion.
A 45-year-old patient presented to the hospital with rest pain and a nonhealing ulcer of 1-month’s duration. The patient was obese, diabetic, and a previous smoker. The laser and balloon angioplasty procedure in the popliteal and peroneal arteries was successful and restored straightline blood flow. One day after the procedure, with rest pain relieved, the patient was discharged from the hospital. No further interventions were required during the follow-up period. The patient completed the LACI study with no rest pain and had healthy tissue (Figure 3A-C).
The LACI study showed that excimer laser-assisted endovascular intervention in CLI results in high procedural success with few in-hospital complications, allowing for the treatment of complex disease characterized by multiple stenoses and occlusions. Excellent limb salvage rates in excess of 90% can be achieved with a very low incidence of surgical reintervention in high-risk patients who are poor candidates for surgical revascularization.
Alicia Fagan is a freelance medical writer. She holds no financial interest in any product or manufacturer mentioned herein. Material adapted from a presentation by John R. Laird, Jr, MD, entitled, “Featured Lecture: Resurrection of Laser Technology in Peripheral Vascular Disease–Final LACI Results” given on September 18, 2003, at the Transcatheter Cardiovascular Therapeutics Meeting in Washington DC.