XPS enables visualization of electrode potential screening in an ionic liquid medium with temporal- and lateral-resolution.

We present an X-ray photoelectron spectroscopic (XPS) investigation of potential screening across two gold electrodes fabricated on a porous polymer surface which is impregnated with the ionic liquid (IL) N-N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)imide [DEME-TFSI]. The IL provides a sheet of conducting layers to the insulating polymer film, and allows monitoring charging and screening dynamics at the polymer + IL/vacuum interface in a laterally resolved fashion across the electrodes. Time-resolved measurements are also implemented by recording F1s peaks of the IL, while imposing 10 mHz square-wave (SQW) pulses across the two electrodes in a source-drain geometry. Variations in the F1s binding energy reflect directly the transient local electrical potential, and allow us to visualize screening of the otherwise built-in local voltage drop on and across the metal electrodes in the range of millimeters. Accordingly, the device is partitioned into two oppositely polarized regions, each following polarization of one electrode through the IL medium. On the other extreme, upon imposing relatively fast 1 kHz SQW pulses the charge screening is prevented and the device is brought to assume a simple resistor role. A simple equivalent circuit model also reproduces the observed voltage transients qualitatively. The presented structure and variants of XPS measurements, enabling us to record voltage transients in unexpectedly large lateral distances away from the electrodes, can impact the understanding of various electrochemical concepts.

Radiofrequency-induced thermal therapy: results of a European multicentre study of resistive ablation of incompetent truncal varicose veins.

OBJECTIVES: To investigate the effectiveness of bipolar radiofrequency-induced thermal therapy (RFITT) in a multicentre non-randomized study. METHODS: Some 672 incompetent saphenous veins (85% great saphenous varicose vein, 15% short saphenous vein) in 462 patients (56.5% CEAP [clinical, aetiological, anatomical and pathological elements] class 3 or worse) were treated in eight European centres. Patients were assessed between 180 and 360 days postoperatively. Occlusion rates were determined by duplex ultrasound and compared with the power used for treatment, pull back rate and experience of the operating surgeon. RESULTS: Complete occlusion rates of 98.4% were achieved when treatments were performed by an experienced operator (more than 20 cases), when the maximum power setting on the RFITT generator was between 18 and 20 W and the applicator was withdrawn at a rate slower than 1.5 second/cm CONCLUSIONS: RFITT is efficacious, well tolerated by patients and has a low incidence of procedure-related post-operative complications.

Endovascular treatment of profunda femoris artery obstructive disease: nonsense or useful tool in selected cases?

BACKGROUND: To evaluate the therapeutic value of endovascular techniques for the treatment of profunda femoris artery obstructive disease (PFAOD) in critical limb ischaemia (CLI) patients, with technically demanding open profunda repair. DESIGN: Retrospective study of prospectively collected data of 15 consecutive CLI patients with technically demanding surgical treatment of PFAOD, that were treated by endovascular means in two European Centers of Vascular Surgery. MATERIALS: All patients had critical limb ischaemia with a history of at least two previous vascular reconstructions in the ipsilateral groin and severe co-morbid conditions. All patients had good common femoral artery flow, long occlusion of the superficial femoral and popliteal arteries and impairment of crural arteries. METHODS: Twelve patients underwent balloon angioplasty alone and, in the other three cases, an additional stent placement was necessary, due to flow-limiting dissection. The follow-up (mean 29.2+/-10 months) included a surveillance protocol with the best medical treatment and duplex scanning at 1, 3, 6, 12 months and yearly thereafter. RESULTS: The endovascular approach was technically successful in all cases and the procedure-related morbidity and mortality rates were 0% for the entire follow-up period. The 3-year primary and secondary patency rates of the treated segment were 80% and 86.7%, respectively. The limb salvage rate was 93.3%. CONCLUSIONS: The outcome of our series underscores the therapeutic value of balloon angioplasty in cases of severe PFAOD, as bailout treatment in critical limb ischaemia patients with technically demanding open profunda repair. This procedure can be repeated easily if significant restenosis occurs and provides a useful tool in selected cases.

Efficacy of a new prostaglandin E1 regimen in outpatients with severe intermittent claudication: results of a multicenter placebo-controlled double-blind trial.

For the first time efficacy and safety of a new prostaglandin E1 (PGE1) regimen in the treatment of intermittent claudication were evaluated in a randomized, double-blind, placebo-controlled multicenter clinical trial. The study involved 213 outpatients with a maximum walking distance of 50 to 200 m measured on the treadmill (3 km/hr, 12% grade). After a 2-week run-in phase they received a 2-hour intravenous infusion of 60 micrograms PGE1 or placebo 5 days a week for 4 weeks. It was followed by a 4-week interval treatment with the same medication administered only twice a week. Patients were monitored for 3 months when they received no study medication. In the PGE1 group the intention-to-treat analysis (n = 208) revealed an increase in walking distance after 4 weeks of 75% (placebo, 43%). At the end of the interval treatment the walking distance had improved to 101% (placebo, 60%). The results remained virtually constant during follow-up (PGE1, 104%, placebo, 63%). Between-group comparisons showed significant differences in favor of PGE1 for all three time points of measurement (p < 0.05, p < 0.01, and p < 0.05). PGE1 was well tolerated; the rate of adverse reactions related to the treatment was 12.8% (placebo, 7.7%). In summary, these results show that the new PGE1 regimen is effective and safe in the treatment of outpatients with intermittent claudication.