Peripheral embolic events during endovascular treatment of infra-inguinal chronic total occlusion

Incidence, risk factors, treatment and prognosis of popliteal artery embolization in the superficial femoral artery interventions

Objective

Percutaneous transluminal angioplasty and stenting (PTA + stent) has gained acceptance as a primary treatment modality for the superficial femoral artery (SFA) diseases. Popliteal artery embolization (PAE) is a severe complication in SFA interventions. The purpose of this study was to evaluate the incidence, risk factors, treatment and prognosis of PAE in primary SFA PTA + stent.

Methods

Chronic SFA arteriosclerosis cases that underwent primary PTA + stent were reviewed from a retrospectively maintained database. Runoff vessels were evaluated in all cases before and after the interventions for PAE detection. The primary patency, secondary patency and limb salvage rates were calculated using Kaplan-Meier analysis and compared using log-rank analysis. Cox multivariate regression was performed to evaluate predictors of patency and limb salvage rates.

Results

There were 436 lesions treated in 388 patients with 10 PAE events (2.3%) in total. PAE rate was significantly higher in Transatlantic Inter-Society Consensus (TASC) C/D group compared with TASC A/B group (OR = 8.91, P = .002), in chronic total occlusion (CTO) lesions compared with stenotic lesions (P<.0001), and in group with history of cerebral ischemic stroke (OR = 6.11, P = .007). PAE rates were not significantly affected by age, sex, smoking, hypertension, diabetes, hyperlipidemia and runoff status. The binary logistic regression showed that only the TASC C/D was an independent predictor of PAE (P = .031). The 12-month and 24-month primary patency, secondary patency and limb salvage rates in PAE group showed no significant differences comparing with non-PAE group.

Conclusions

PAE is a rare event in primary SFA PTA + stent. TASC C/D lesion, CTO and cerebral ischemic stroke history are risk factors for PAE. PAE is typically reversible by comprehensive techniques. If the popliteal flow is restored in time, PAE has no significant effect on long-term patency and limb salvage rates.

Treatment of subacute and chronic thrombotic occlusions of lower extremity peripheral arteries with the excimer laser: a feasibility study

BACKGROUND

Thrombus is highly prevalent in patients with recent symptoms (< 6 months) of claudication or limb ischemia due to an occluded culprit lower extremity vessels. Treatment of these thrombotic occlusions is challenging. In this feasibility study, the excimer laser (Spectranetics, Colorado Springs, CO) has been tested for its safety and ability to ablate thrombus in patients with recent arterial occlusions.

METHODS

Angiographic operator assessment and volumetric core lab quantitation of the thrombus were performed at baseline and after excimer laser but prior to definitive treatment of the vessel to evaluate thrombus resolution. Consecutive patients were prospectively enrolled at a single site. Procedural success was defined as achieving a residual stenosis of <30% after final treatment with no intraprocedural complications requiring additional treatment.

RESULTS

20 consecutive patients were enrolled in this study (8 males, mean age 69.5±11.1 years). Based on patients symptom onset, 12 patients were subacute (> 24 h, < 30 days), and 8 chronic (between 1 to 6 months). 15/20 (75%) had restenotic occlusions. Due to the long, occlusive nature of these lesions, only 8 patients had complete intravascular ultrasound images at each time point which allowed volumetric analysis by the core lab. There was no statistical difference in plaque/thrombus volume between baseline (pretreatment) and excimer laser (P=.68). There was however a significant reduction in residual angiographic stenosis post laser alone (100% vs. 66.75%±23.9%, P=.001). Procedural success was 100%. There were no deaths or amputations. Bail out stenting was performed in 10/20 (50%) patients. Embolic filters were used in 15/20 (75%) of patients. Macrodebris>2 mm were seen in 85.7% of filters. There was no in-hospital or 30-day reocclusion of the treated vessel but one patient had a vascular access complication (small AV fistula) conservatively managed. No other serious adverse events were noted.

CONCLUSION

Using the excimer laser appears safe in this small feasibility study of subacute and chronic thrombotic occlusions. Angiographically, there was a significant reduction in percent stenosis with the laser alone. The limited IVUS data did not show a reduction in plaque/thrombus volume but the number of interpretable ultrasounds was small. Further data are needed to address the effectiveness of the laser in treating these thrombotic occlusions and its advantages over balloon angioplasty.