Lesion types and device characteristics that predict distal embolization during percutaneous lower extremity interventions.

OBJECTIVE: Distal embolization (DE) during percutaneous lower extremity revascularization (LER) may cause severe clinical sequelae. To better define DE, we investigated which lesion types and treatment modalities increase the risk for embolization. METHODS: A prospective registry of LER from 2004 to 2009 was reviewed. All cases with runoff evaluated before and after intervention were included. Angiograms and operative reports were reviewed for evidence of DE. Interventions included percutaneous transluminal angioplasty (PTA), with or without stent placement, and atherectomy with four different devices. Chi-square analysis and Fisher's exact test were used to assess significance. Patency rates were calculated using Kaplan-Meier analysis and compared using log-rank analysis. RESULTS: There were 2137 lesions treated in 1029 patients. The embolization rate was 1.6% (34 events). Jetstream (Pathway, Kirkland, Wash) and DiamondBack 360 (Cardiovascular Systems Inc, St Paul Minn) devices had a combined embolization rate of 22% (8 of 36), 4 of 18 (22%) in each group, which was significantly higher than with PTA alone (5 of 570, 0.9%), PTA and stent (5 of 740, 0.7%), SilverHawk (ev3, Plymouth, Minn) atherectomy (14 of 736, 1.9%), and laser atherectomy (2 of 55, 3.6%; P < .001). There was a significantly higher rate of embolization for in-stent restenosis (6 of 188, 3.2%) and chronic total occlusions (15 of 615, 2.4%) compared with stenotic lesions (13 of 1334, 0.9%; P = .01). The embolization rate was significantly higher in Transatlantic Inter-Society Consensus (TASC) II C and D lesions compared with TASC A and B lesions (P = .018). DE rates were not affected by preoperative runoff status (P = .152). Patency was restored at the completion of the procedure in 32 of 34 cases of DE. The 24-month primary patency, assisted primary patency, and secondary patency in the DE group was 54.0% ± 11.9%, 70.0% ± 10.3%, and 73.2% ± 10.3%, respectively, and was 44.4% ± 1.7%, 61.5% ± 1.7%, and 68.2% ± 1.6%, respectively, when embolization did not occur (P > .05). Limb salvage was 72.6% ± 3.1% in lesions in which no DE occurred vs 83.3% ± 15.2% in lesions in which DE occurred (P = .699). CONCLUSIONS: DE is a rare event that occurs more often with the Jetstream and DiamondBack 360 devices. In-stent and complex native lesions are at higher risk for DE. DE is typically reversible with endovascular techniques and has no effect on patency rates and limb salvage.

Closed-cell stents present with higher velocities on duplex ultrasound compared with open-cell stents after carotid intervention: short- and mid-term results.

BACKGROUND: The purpose of this study was to evaluate the effect of carotid cell design on duplex ultrasound velocity readings in the immediate postoperative period and over time. METHODS: A prospective database encompassing all patients treated with carotid artery stents between 2003 and 2008 was established and analyzed for stent type (closed-cell vs. open-cell), indications, and comorbidities. Patients were followed up clinically and with duplex ultrasound immediately after surgery, and every 6 months thereafter. Peak systolic velocities (PSV), end diastolic velocities (EDV), and internal carotid artery (ICA) to common carotid artery (CCA) ratios of PSV were recorded. RESULTS: A total of 214 interventions with 157 (73.3%) open-cell and 57 (26.7%) closed-cell types of carotid stents were performed in 205 patients. Two groups were similar regarding demographics, comorbidities, lesions characteristics, and stent length and diameter. The only difference was a significantly higher mean age (74.4 ± 10.1 vs. 70.9 ± 9.7 years; p = 0.027) and a history of myocardial infarction (34.5% vs. 15.6%; p = 0.004) in the closed-cell group versus open-cell group. Immediately after surgery PSV (115.9 ± 66.1 vs. 93.1 ± 38.7 cm/s; p = 0.003) and ICA/CCA ratio (2.08 ± 1.66 vs. 1.45 ± 0.52; p = 0.001) were significantly higher in closed-cell compared with open-cell group. This difference persisted during the follow-up period of 20.2 +/- 16.4 months; PSV (147.2 ± 108.8 vs. 110.0 ± 51.9; p = 0.003) and ICA/CCA ratio (2.61 ± 2.31 vs. 1.76 ± 0.81; p = 0.001). Patients with diabetes and calcified lesions had higher PSV and ICA/CCA ratio immediately after surgery (p > 0.05 and p < 0.05 for those with diabetes and calcified lesions, respectively) and over time. The number of readings showing significant restenosis (PSV >300 cm/s) over time were significantly higher in closed-cell 5 (8.7%) versus open-cell 1 (0.06%). EDV was not statistically different in the two groups (p > 0.05). CONCLUSION: Our study suggests that duplex criteria to screen for poststent restenosis may require modification according to stent-type. However, long-term effect of stent design on restenosis is still to be established.