Technical aspects of entrapped coronary guidewire retrieval using rotational atherectomy device: A case series.

BACKGROUND: This article highlights four unique cases where rotational atherectomy (RA Rotapro, Boston Scientific) was used to cut and retrieve an entrapped coronary guidewire with parts extending into the aorta We discuss the technique and step by step approach to the retrieval procedure. CASE SUMMARY: Three of four cases described a guide wire entrapment in the right coronary artery (RCA), and one in the left anterior descending artery via retrograde route. In all cases the guide wire was intact within the intracoronary segment. In Case 1, the guide wire (Runthrough; Terumo) was entrapped in an acute marginal branch during chronic total occlusion (CTO) percutaneous coronary intervention. In Case 2, a whisper wire (Abbott) was entrapped during re-wiring of the right posterolateral branch through stent struts, the traction on the wire caused severe malformation of distal and proximal stents requiring second staged procedure to complete revascularization of the RCA CTO. In Case 3, a Runthrough wire was entrapped between two layers of stents and fractured at the proximal point with filaments extending into descending aorta. And in Case 4, a Pilot 200 (Abbott) wire was entrapped retrograde in the subintimal space via saphenous vein graft connection by tying a knot at the distal tip of the wire. In all four cases RA was used to successfully cut and remove the entrapped guide wires. DISCUSSION: Rotablation technique appears to be a safe and effective strategy for the management of entrapped coronary guidewire when conventional strategies fail.

Effect of concentrated light on morphology and vibrational properties of boron and tantalum mixtures.

Heating a mixture of boron (impurities: carbon ∼ B50C2, boric acid - H3BO3) and tantalum (Ta) powders in nitrogen flow in a xenon high-flux optical furnace was performed. As-received powder composed of h-BN, H3BO3, TaB2, B9H11 and a number of other phases including ß-rhombohedral boron, apparently, heavily doped with Ta. FT-IR examination of any sample of the material reveals the complicated vibration spectrum containing, in particular, an absorption band near 2260 cm-1. The shapes of these bands are different for samples because powders were synthesized at different temperatures. Known, that in ß-rhombohedral boron lattice, there are nano-sized voids of different types, which allow an accommodation of single atoms or small groups of atoms. Theoretical calculations performed by the method of quasi-classical type yields the same value, 2260 cm-1, for the vibrations frequency of Ta atoms in D-type crystallographic voids in ß-rhombohedral boron lattice. Since, Ta atoms are known to prefer accommodation just in D-voids the experimentally detected bands can be identified with localized vibrations of Ta atoms.