Analysis of Subjective and Objective Screening Techniques as Predictors of Safety for Radial Artery Intervention.

BACKGROUND: There is no currently accepted standard in safety evaluation for radial artery intervention. We sought to compare the accuracy of various subjective and objective screening techniques in predicting safety for radial artery intervention. METHODS: Fifty-four patients in a prospective cohort study at a single institution underwent subjective Allen's test, objective Barbeau test, and several objective hand ultrasound techniques to assess safety for radial artery intervention. These results were then compared to the gold standard of conventional hand angiography to document complete palmar arch. Statistical analysis including sensitivity, specificity, positive predictive values, negative predictive values, and accuracy were calculated. RESULTS: Compared to hand angiography, the subjective Allen's test and the objective Princeps Pollicis Artery ultrasound demonstrated the comparable levels of sensitivity (100% vs. 96.7%, respectively), specificity (100% vs. 100%, respectively), and accuracy (97.2% vs. 97.1%, respectively). The objective Barbeau test demonstrated similar results (sensitivity of 100%, accuracy of 98.2%) with the exception of a lower specificity (50%). CONCLUSIONS: There is no currently accepted standard in safety evaluation for radial artery intervention. However, preliminary data suggest that certain subjective and objective techniques such as Allen's testing, Princeps Pollicis artery ultrasound, and Barbeau testing are comparable options in predicting palmar arch patency.

Management of Calcification: Rational and Technical Considerations for Intravascular Lithotripsy.

Arterial calcification (AC) is a common complication among patients with peripheral arterial disease (PAD). AC presents various challenges to PAD treatment including an increased likelihood of vessel rupture and dissection, and by acting as a physical barrier to drug delivery by angioplasty balloons. Intravascular lithotripsy (IVL) is a novel intervention that specifically targets AC by emitting sonic pressure waves that introduce microfractures in target calcified lesions to increase arterial compliance. Preliminary data has demonstrated the safety and efficacy of IVL in PAD treatment. The present article provides a technical overview of S-IVL, as well as a case series of the treatment of AC in common iliac, common femoral, superficial femoral, aortoiliac, and peroneal arterial lesions. Each case resulted in marked improvement of luminal patency, exhibiting the efficacy IVL.

Technical Approach to Percutaneous Femoropopliteal Bypass and Deep Vein Arterialization.

In the management of patients with critical limb ischemia endovascular revascularization plays a crucial role improving amputation-free survival, ischemic rest pain, and wound healing. Endovascular standard of care of peripheral arterial occlusive disease involves angioplasty and/or stent placement. The following discussion is intended to familiarize interventional physicians with the rationale, physiological concepts, and technical approach to developing endovascular procedures-percutaneous femoropopliteal bypass and percutaneous deep vein arterialization. Percutaneous arterial bypass procedure is designed to treat long complex Trans-Atlantic Inter-Society Consensus C and D hemodynamically significant superficial femoral artery lesions by redirecting the flow of blood from the diseased arterial segment through a femoral vein conduit. Percutaneous deep vein arterialization is used for selected "no-option" critical limb ischemia patients who cannot undergo or have failed conventional endovascular and/or surgical revascularization due to extensive occlusion of the outflow arteries. It involves creation of an arteriovenous fistula between a tibial artery and a tibial vein, disruption of venous valves, and elimination of venous collaterals. The consequent arterialization of the distal venous bed enables delivery of oxygenated pressurized arterial blood to the ischemic tissues, stimulating angiogenesis and increasing flow in the existent collateral vessels, which in turn will improve limb salvage and amputation free survival.

Evidence for water-permeable channels in auditory hair cells in the leopard frog.

Auditory hair cells in the amphibian papilla (APHCs) of the leopard frog, Rana pipiens pipiens, have a significantly higher permeability to water than that observed in mammalian hair cells. The insensitivity of water permeability in frog hair cells to extracellular mercury suggests that an amphibian homologue of the water channel aquaporin-4 (AQP4) may mediate water transport in these cells. Using immunocytochemistry, we show that an AQP4-like protein is found in APHCs. Rabbit anti-AQP4 antibody was used in multiple-immunohistochemical staining experiments along with AP hair cell and hair bundle markers in leopard frog and mouse tissue. AQP4 immunoreactivity was found in the basal and apical poles of the APHCs and shows uniform immunoreactivity. This study provides the first identification and localization of an AQP4-like protein in the amphibian inner ear. We also report a more direct measure of hyperosmotically-induced volume changes in APHCs that confirms previous findings. The presence of water channels in anuran APHCs constitutes a novel physiological difference between amphibian and mammalian hair cell structure and function.