As coronary stenosis severity increased, graft flow increased, pulsatility index decreased, and proportion of patients with systolic reverse flow increased. In mild coronary artery stenosis, the chance of flow competition between the native coronary artery and the bypass graft increased.

It has been reported that in the excised cross-circulated dog heart model, cardiac cooling increases Emax (contractility index) and the external work (EW) of the left ventricle without affecting the systolic pressure volume area (PVA)-independent myocardial oxygen consumption (VO2). However, it remains unclear whether this cooling inotropism and oxygen-saving effect can also be demonstrated in an in situ heart. In the present study, we investigated the effect of cardiac cooling under surface-induced hypothermia in the in situ heart to assess the practical application of this method. Adult mongrel dogs were examined under surface-induced hypothermia with or without vasodilator. Using conductance catheter, pressure-volume relationship were obtained and mechanoenergetical parameters were measured. Optimal temperature for cardiac cooling was also examined. Simple hypothermia increased Emax compared with normothermia without affecting PVA-independent VO2, but EW did not increase. However, with concurrent vasodilator administration, cardiac cooling increased not only Emax but also EW without affecting PVA-independent VO2 compared with normothermia. However, at temperature below 32 degrees C, Tau increased significantly and diastolic dysfunction was noted. Cardiac cooling with concurrent vasodilator administration in the in situ heart has inotropic and oxygen-saving effects and optimal temperature for cardiac cooling is thought to be 34 degrees C.

This investigation aimed to clarify the issue of whether polymer chains are entangled in ultrathin films spin-coated onto substrates. This was done using a fluorescence probe method to observe the behavior of two types of poly(methyl methacrylate) (PMMA), one having a carbazolyl (Cz) moiety (PMMA-Cz) and the other having an anthryl (At) moiety (PMMA-At). In both cases, the moiety fraction was 1 unit for 400 units of polymer. We prepared ultrathin films (thickness: 4-88 nm) on quartz substrates from PMMA-Cz, PMMA-At, and a mixture of the two using a spin-coating method. When the PMMA films prepared from the mixture of the two PMMAs were excited at 292 nm, which is preferentially absorbed by Cz rather than At, the Cz fluorescence was found to be quenched dramatically while the At fluorescence increased significantly. This effect is due to the proximity of the Cz to the At, which permits the transfer of excitation energy between them. The average distance between Cz and At can be calculated using the Förster mechanism. When the ultrathin film thickness was between 12 and 88 nm, the average distance was found to be 2 nm. This is much shorter than the radii of gyration of the polymers. From this it is clear that two polymer molecules in an ultrathin film do experience entanglement, as has been hypothesized. Thus, we conclude that the difference between certain properties of ultrathin films and the properties of the same materials in bulk are not induced by a decrease in the level of polymer chain entanglement.

We report two patients who developed a tracheo-innominate artery fistula (TIF) after tracheostomy. Contrast-enhanced computed tomography revealed a pseudoaneurysm of the innominate artery protruding into the trachea. Stent grafts were deployed for the innominate artery via two different access routes: the transfemoral approach and the right carotid artery approach. Endovascular stent-graft repair resulted in complete exclusion of the TIF and control of the bleeding from the tracheal stoma. At 12- and 16-month follow-ups, neither patient had clinical signs of graft infection, recurrent fistulization, or ischemic complications. It is feasible and useful to employ the carotid artery approach for stent-graft implantation in patients who have vascular anatomical limitations for the transfemoral approach. Endovascular repair of TIF by stent grafting is a minimally invasive treatment that can be tolerated by patients in poor clinical condition, and is a feasible alternative to surgical treatment.

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