Axillary cerebral perfusion for arch surgery in acute type A dissection under moderate hypothermia

Backgound: Aortic arch surgery is still associated with increased mortality and morbidity especially in acute type A aortic dissection. Adequate brain protection is essential and commonly performed by either antegrade selective perfusion of the brachiocephalic arteries or an interval of profound hypothermic circulatory arrest. We present our experience for open aortic arch repair with continuous antegrade brain perfusion by means of direct cannulation of the right axillary artery, under moderate hypothermia in patients with acute type A aortic dissection. Methods: In, 25 consecutive patients (17 men) with a mean age of 62.6 ± 14.8 years, aortic repair extended to the arch, for acute type A aortic dissection, was performed through a midline sternotomy. The right axillary artery was used for arterial systemic and brain perfusion at a rectal temperature of 25-27 °C. Results: Mean duration of CPB and aortic cross-clamping was 241 ± 55 and 155 ± 72 min, respectively. The mean duration of circulatory arrest of the lower body and brain perfusion was 39.7 (range, 24-55 min). All the patients survived the procedure and all but one were discharged from hospital. One patient had left arm paralysis which he recovered the first postoperative month. There were no other transient or permanent neurologic deficits. A CT scan was performed at discharge for routine postoperative evaluation. There were no local neurovascular complications related to the cannulation site except for one local re-exploration for bleeding. Conclusions: The absence of any major permanent neurologic deficit or any visceral damages in our patients suggests that continuous moderate hypothermic cerebral perfusion, with an interval of circulatory arrest of the lower body, is adequate for acute type A aortic dissection surgery, allowing safe open repair of the distal aortic arc

Highly sensitive luminescence nanothermometry and thermal imaging facilitated by phase transition

Currently available temperature measurements or imaging at nano-micro scale are limited to fluorescent molecules and luminescent nanocrystals, whose spectral properties respond to temperature variation. The principle of operation of these conventional temperature probes is typically related to temperature induced multiphonon quenching or temperature dependent energy transfers, therefore, above 12%/K sensitivity and high thermal resolution remain a serious challenge. Here we demonstrate a novel class of highly sensitive thermographic phosphors operating in room temperature range with sub-kelvin thermal resolution, whose temperature readings are reproducible, luminescence is photostable and brightness is not compromised by thermal quenching. Corroborated with phase transition structural characterization and high spatio-temporal temperature imaging, we demonstrated that optically active europium ions are highly and smoothly susceptible to monoclinic to tetragonal phase transition in nanocrystalline (54 ± 14 nm) LiYO2 host, which is evidenced by changed number and the splitting of Stark components as well as by smooth variation of contribution between magnetic and electric dipole transitions. Further, reducing the size of phosphor from bulk to nanocrystalline matrix, shifted the phase transition temperature from 100 °C down to room temperature. These findings provide insights into the mechanism underlaying phase transition based luminescence nanothermometry and motivate future research toward new, highly sensitive, high temporal and spatial resolution nano-thermometers aiming at precise studying heat generation or diffusion in numerous biological and technology applications

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

Blood supply of the digital sheath

One hundred upper extremities from fresh human cadavers aged 20 to 80 years were injected with coloured latex or Indian ink and gelatin. Under the dissecting microscope two main and one occasional source of vascularization of the digital sheath were identified. Originating from the digitopalmar arches, from the proper palmar digital arteries and occasionally from the arcus palmaris superficialis, a complex arterial system supplies the various parts of the digital sheath. The best vascularized area is the floor of the sheath, while the pulleys and the palmar surface of the sheath are less well vascularized. These data may be of interest to those involved in reconstruction of the tendons of the digital flexor muscles