Prospective Single-Arm Trial of Endovascular Mechanical Debulking as Initial Therapy in Patients With Acute and Subacute Lower Limb Ischemia: One-Year Outcomes.

PURPOSE: To report the results of a prospective, single-arm study to establish whether the initial treatment of acute or subacute limb ischemia (ALI and SLI, respectively) can be accomplished successfully using endovascular mechanical debulking of the target vessels to avoid the risks associated with thrombolysis and/or open surgery. MATERIALS AND METHODS: From April 2009 to April 2015, 316 consecutive patients (mean age 70.9±12 years; 184 men) with ALI (202, 63.9%) or SLI (114, 36.1%) were enrolled; the only exclusion criterion was irreversible ischemia. The ALI group included 146 (72.3%) participants with category IIb ischemia and 56 (27.7%) with category IIa. Critical limb ischemia was diagnosed in 74 (64.9%) of the 114 patients with SLI. Target occlusions of thrombotic (n=256) or embolic (n=60) origin were located in the femoropopliteal segment (n=231), prosthetic or venous femoropopliteal bypass grafts (n=75), and the aortoiliac segment (n=35). The mean occlusion length was 22.9±14.8 cm. RESULTS: The overall technical success (residual stenosis ≤30%) was 100% after debulking and adjunctive techniques (aspiration, dilation, stenting) at the level of the target lesions. No open surgical or thrombolytic modalities were necessary to bypass or recanalize the target vessels, and no death occurred in association with target occlusion therapy. Additional infrapopliteal interventions were performed in 195 (61.7%) patients (adjunctive thrombolysis in 29) to treat acute, subacute, and chronic lesions. Minor complications directly related to the debulking procedure occurred in 26 (8.2%) patients. Serious complications occurred in 11 (3.5%) patients, including hemorrhage in 8 (2.5%) patients (associated with infrapopliteal thrombolysis in 5). At 30 days, primary and secondary patency rates were 94.3% and 97.2%, respectively; mortality was 0.3% (1 fatal intracranial hemorrhage after adjunctive thrombolysis). Of 229 patients eligible for 1-year follow-up, amputation-free survival was estimated to be 87.4% in 199 patients with available data. CONCLUSION: In this all-comers study, mechanical debulking with the Rotarex alone or with adjunctive techniques is feasible as a primary therapy for occluded supratibial vessels in patients with ALI or SLI.

Angle of Observation Influence on Emission Signal from Spatially Confined Laser-Induced Plasmas.

The present work focuses on the influence of the angle of observation on the emission signal from copper plasmas. Plasma plumes have been generated inside a home-made chamber consisting of two parallel glass windows spaced by 2.5 mm. This chamber allows observing plasma plumes from different collection angles throughout their perimeter, spanning from 20° to 80° with respect to the surface of the Cu target. In order to minimize the observed volume of the plasma, measurements were made from the closest distance possible through a metallic hollow tube. Single-pulse and collinear double-pulse excitation schemes with a Nd:YAG laser (1064 nm, 5 ns) have been investigated. The results have shown that the selection of the best angle to collect light from the plasma is related to the excitation mode. On the other hand, the shot-to-shot signal variability has been found to depend on the shape of plasma plumes. In single-pulse excitation, a good correlation between the observed laser-induced breakdown spectroscopy (LIBS) emission (from spatially confined plumes) and their integrated signal of plasma image has been ascertained. However, this fact was less evident in double-pulse LIBS, which could be due to a different mechanism involved in the ablation process.