Real-Time Cardiac Catheter Navigation on Three-Dimensional CT Images

Introduction: Targets for ablation of atrial fibrillation, atrial flutter, and non-idiopathic ventricular tachycardia are increasingly being selected based on anatomic considerations. Because fluoroscopy provides only limited information about the relationship between catheter positions and cardiac structures, and is associated with radiation risk, other approaches to mapping may be beneficial. Methods: The spatial and temporal information of an electromagnetic catheter tip position sensing system (Magellan, Biosense Inc.) was superimposed on a three-dimensional (3D) CT of the chest in swine using fiducial markers for image registration. Position and orientation of a 6 French catheter with an electromagnetic sensor was displayed in real-time on a corresponding 3D-CT. Catheter navigation within the heart and the great vessels was guided by detailed knowledge about catheter location in relation to cardiac anatomy. Results: Anatomic structures including the atrial septum, pulmonary veins, and valvular apparatus were easily identified and used to direct catheter navigation. During the right heart examination, the catheter was navigated through the superior and inferior vena cava to predetermined anatomic locations in right atrium, right ventricle and pulmonary artery. The ablation catheter was also navigated successfully from the aorta through the aortic valve in the left ventricle. No complication was encountered during the experiments. The accuracy and precision of this novel approach to mapping was 4.69 ± 1.70 mm and 2.22 ± 0.69 mm, respectively. Conclusions: Real-time display of catheter position and orientation on 3D-CT scans allows accurate and precise catheter navigation in the heart. The detailed anatomic information may improve anatomically based procedures like pulmonary vein ablation and has the potential to decrease radiation times.     

Metabolic Evidence for Cerebral Neurodegeneration in Spinocerebellar Ataxia Type 1

Autosomal-dominant spinocerebellar ataxia type 1 (SCA1) is an adult-onset progressive disorder with well-characterized neurodegeneration in the cerebellum and brainstem. The objective of this study is to evaluate neurochemical changes associated with neurodegeneration in cerebral tissue in SCA1 patients compared to age- and gender-matched healthy controls. Nine patients with genetically proven SCA1 and nine gender- and age-matched healthy controls were prospectively recruited from the ataxia clinic and received clinical examination. A 1.5 T single-voxel brain proton MR spectroscopy was performed for total N-acetyl aspartate (tNAA) in cerebellum, parietofrontal lobe white matter, sensory cortex, and visual cortex. In the patients, tNAA was severely decreased in the cerebellar voxel; however, in the voxels positioned in sensory cortex, parietofrontal lobe white matter and visual cortex tNAA was reduced in comparison to controls. In addition to the profoundly affected cerebellum, we also found evidence for cerebral neurodegeneration in parietal lobe white matter, sensory cortex, and visual cortex in SCA1 patients illustrating a multisystem neurodegenerative character of the disease.     

Prognostic Significance of Somatostatin Receptor Heterogeneity in Progressive Neuroendocrine Tumor Treated with Lu-177 DOTATOC or Lu-177 DOTATATE

European Journal of Nuclear Medicine and Molecular Imaging - One of the primary prerequisites for peptide receptor radionuclide therapy (PRRT) in patients with neuroendocrine tumors (NET) is the...     

Differential impact of belatacept and cyclosporine A on central aortic blood pressure and arterial stiffness after renal transplantation

Calcineurin inhibitors (CNI) are potent vasoconstrictors and induce an acceleration of arteriosclerosis, thus contributing to the cardiovascular risk after renal transplantation. The study compares the impact of belatacept and cyclosporine A (CsA) on arterial stiffness and central aortic blood pressure. We performed a case–control study in 46 patients (23 on belatacept and 23 on CsA) matched for age, body mass index, time after transplantation, and time on dialysis prior to transplantation. Pulse wave analysis (SphygmoCor, AtCor^®) was used to assess central aortic blood pressure, aortic augmentation pressure, and pulse wave velocity (PWV) as a marker of arterial stiffness. Assessment of vascular function was performed after a minimum of 20 months and a median follow‐up of 81 months post‐transplant. Peripheral systolic and diastolic blood pressure did not significantly differ in the two groups (p > 0.05 each). The central aortic augmentation pressure was higher in the CsA group (12.7 mmHg vs. 7.3 mmHg, p = 0.048). PWV as a measure of arterial stiffness did not differ in the two groups. Thus, belatacept is not associated with a significant difference in arterial stiffness compared to CsA after a median of 81 months post‐transplant. It is associated, however, with a lower aortic augmentation pressure, a strong independent cardiovascular risk factor.     

Morphometric study of the scapular free flap and the free rib osteomyocutaneous flap

The scapula free flap is often the first choice for reconstruction of bony defects of the facial skeleton. However, the vascularised rib as part of a free rib osteomyocutaneous flap may be a suitable second choice. We have investigated the morphology and clinical dimensions of the 7th rib and the scapula, and the ability of the available bone to carry dental implants. The age and sex of the cadaver, and the donor side, were also recorded. The dimensions of the scapulas and 7th ribs (n = 130 of each) from 65 cadavers were measured at 4 different points using osteometric methods. Examination showed that bone from the scapula and 7th rib were sufficient for placement of implants. The 7th rib gave reliable measurements for both height and width, and a consistent relation between compact and cancellous bone. Although the scapula provided adequate compact and cancellous bone, there were variations depending on the segment of bone chosen. Bones from male cadavers were more suitable for implantation. In both the scapula and the 7th rib ageing had a significant adverse effect in only one dimension. Most points of measurement have satisfactory bony dimensions for insertion of dental implants.     

Locking versus nonlocking plates in mandibular reconstruction with fibular graft—a biomechanical ex vivo study

Objectives

The main goal of the present study was to compare the biomechanical stability of locking plates and conventional miniplate combinations in human mandibles reconstructed with fibular grafts.

Materials and methods

A specially developed and well-proven testing device reproduced the in vivo loading conditions on the mandible. Cadaveric human mandibles (n?=?12) reconstructed with harvested human fibular bone grafts were divided into two groups, and different osteosynthesis systems were applied using two lines of plates per osteotomy. On the test apparatus, the specimens were stressed to failure, and interfragmentary movement was monitored and quantified with a contact-free optical measurement system.

Results

The relevant interfragmentary movement results from a Euclidean summary calculation which considered all three spatial angles around the axes. Using values up to a maximum load of 300 N, the conventional six-hole miniplates (profile 1.0) had an average value of 7.45°?±?1.46°, and the locking six-hole plates (profile 1.3) had an average value of 12.16°?±?2.37° for rotational interfragmentary movement. The miniplate system exhibited a significantly superior performance in fixation compared to the fixed-angle system (p?<?0.05).

Conclusion

According to these biomechanical experiments, both osteosynthesis devices provided sufficient stabilization at loads of up to 300 N. The six-hole miniplate system provided better stabilization of the osteotomy gap for mandibles reconstructed with fibular grafts.

Clinical relevance

The osteosynthesis system is essential for primary stability and the avoidance of pseudarthrosis formation. This study demonstrates that the miniplates provide sufficient stabilization and offers a method to improve fixation in reconstructed mandibles.     

Level of Digitalization in Germany: Results of the Diabetes Digitalization and Technology (D.U.T) Report 2020

Background:New diagnostic and therapeutic technologies are increasingly changing the treatment of people with diabetes (PWD), along with increased usage of digital tools. To date, however, there is little data to which level and how diabetologists and PWD implement digitalization. Also, not much is known about the view of diabetologists on the current status and future developments in this respect.Method:In an online survey, diabetologists working in clinics and practices across Germany provided responses regarding their view on digitalization and the adoption of new technologies in diabetology to 56 questions. These comments reflect the opinion of several experts about the current importance and use of specific digital/technological topics.Results:Overall, 326 diabetologists took part in the survey. They reported a positive attitude (75.8%) toward new technologies and digitalization, and they see more advantages rather than disadvantages. Younger age of the diabetologists was significantly associated with a more positive attitude (r = −0.176; P < .01), and there was no gender effect (P = .738). On average, in each practice, 5.5% of PWD are using an insulin pump for therapy, 4.8% a real-time continuous glucose monitoring system, 16.9% an intermittent scanning continuous glucose monitoring system, and 0.3% an automated insulin delivery (AID) system. With respect to digitalization, the three most important current topics are software for glucose data analysis (average rank on a scale from one to six, with one being the most important: 2.4), compatibility with other systems (2.9), and AID systems (3.8)).Conclusions:This survey, which is going to be repeated annually, showed that the diabetologists who participated predominantly have a positive attitude toward new technologies and digital applications and were aware of the associated advantages. However, perceived disadvantages need to be addressed to enable wider adoption of new technologies and digital solutions.