Preparation of artificial vascularised tissue and the indirect determination of its void volume using µCT.

The non-invasive determination of the vasculature volume would be very useful in many fields of medicine such as oncology and implantation. The purpose of this research was, therefore, to develop a methodology to investigate vascularisation in phantoms using microcomputed tomography (µCT) without having to visualise the single vessels. Epoxy resin and cotton candy were used to form the phantoms with microchannels. The size of the channels was measured via microscopy and the proportion of the void volume (PVV) was calculated. The phantoms were placed in contrast agent solutions of different concentrations and scanned in µCT. The mean CT numbers of the phantoms were calculated with the Amira software and displayed as a function of the determined PVV and the contrast agent concentration (CAC). The fabricated microchannels had the size of biological capillaries (diameter: 5 µm to 15 µm) and the phantoms showed a microchannel density of 5 to15 microchannels per mm². With an increasing CAC, the CT numbers increased significantly. Additionally, the phantoms with a higher PVV also had a higher CT number. The CT numbers and the PVV correlated moderately together, but significantly. The slope of the regression line increased with an increasing CAC.

Clinical Efficacy of Permanent Internal Mammary Artery Occlusion in Chronic Coronary Syndrome: A Double-Blind, Randomized, Sham-Controlled Trial.

The Clinical Efficacy of Permanent Internal Mammary Artery Occlusion in Chronic Coronary Syndrome (CLIMACCS) trial, a randomized, sham-controlled trial, tested the clinical efficacy of permanent internal mammary artery (IMA) device occlusion on symptoms in patients with chronic coronary syndrome (CCS), coronary artery occlusive blood supply, and myocardial ischemia. This was a prospective trial in 101 patients with CCS randomly allocated (1:1) to IMA device occlusion (verum group) or to IMA sham intervention (placebo group). The primary study end point was the change in treadmill exercise time (ET) (ΔET in seconds) at 6 weeks after trial intervention. Secondary study end points were the changes in collateral flow index (CFI) and angina pectoris during a simultaneous 1-minute proximal balloon occlusion of a coronary artery. CFI is the ratio between simultaneous mean coronary occlusive, divided by mean aortic pressure, both subtracted by central venous pressure. In the verum and placebo groups, the ET changed from 398 ± 176 seconds to 421 ± 198s in the verum group (p = 0.1745) and from 426 ± 162 seconds to 430 ± 166 seconds in the placebo group (p = 0.55); ΔET amounted to +23 ± 116s and +4 ± 120 seconds, respectively (p = 0.44). CFI change during follow-up equaled +0.022 ± 0.061 in the verum and -0.039 ± 0.072 in the placebo group (p <0.0001). Angina pectoris at follow-up during the coronary balloon occlusion for CFI measurement had decreased or disappeared in 20 of 48 patients in the verum group and in 9 of 47 patients in the placebo group (p = 0.0242). In conclusion, permanent IMA device occlusion tends to augment treadmill ET in response to increased coronary artery occlusive blood supply, which is reflected by mitigated symptoms and signs of myocardial ischemia.

Blood Vessel Topography of the Feet in Selected Species of Birds of Prey and Owls.

Birds of prey and owls are susceptible to diseases of and traumatic injuries to their feet, which regularly require surgical intervention. A precise knowledge of the blood vessel topography is essential for a targeted therapy. Therefore, the metatarsal and digital vasculature was examined in eight species of birds of prey and owls. The study included contrast micro-computed tomography scans and anatomical dissections after intravascular injection of colored latex. In all examined species, the dorsal metatarsal arteries provided the main supply to the foot and their branching pattern and number differed between species. They continued distally as digital arteries. All examined species showed a basic pattern of four collaterally located digital blood vessels per toe: a prominent artery and small vein on one side and a small artery and prominent vein on the other side. Digital veins united to form common digital veins, most of which joined into a superficial, medially located metatarsal vein. This vein provided the main drainage of the foot. The detailed visualization of the topography of pedal blood vessels will help veterinary surgeons during surgical procedures. In addition, differences in the plantar arterial arch between hawks and falcons were discussed regarding their possible influence on the prevalence of pododermatitis (bumblefoot).