Flying endoscopists in the Arctic: initiatives for quality assurance of endoscopies in Greenland.

BACKGROUND: Surgical coastal expeditions (SCEs) have been organized in Greenland for many years. They aim to provide small coastal hospitals with specialist services, such as endoscopies (SCEEs), by deploying specialist personnel, surgeons, and the necessary equipment to the hospital temporarily. The purpose of this program is to increase accessibility for patients, while simultaneously reducing the costs associated with patient transport to the central hospital. METHODS: This retrospective pilot review of medical records identified quality indicators, such as bowel cleansing (BP), cecal intubation rate (CIR), and adenoma and advanced adenoma detection rates (ADR, AADR), to investigate the status and establish a system for quality monitoring of SCEsE in Greenland. RESULTS: During two SCEs (8 working days), 89 SCEE were performed at Qaqortoq and Sisimiut Hospitals. The 60 patients who underwent colonoscopy included 32 men and 28 women with a mean age of 61 years (range 24-80 years). The unadjusted CIR was 91.7%. In eight (13.3%) examinations, bowel preparation was rated as unsatisfactory, resulting in two incomplete procedures. The ADR and AADR were 35% and 11.7%, respectively, and one cancer was detected (1.7%). CONCLUSION: The results showed satisfactory ADR, AADR, and CIR levels. However, the review also highlighted the need for increased attention to BP by developing a new procedure that considers differences due to specific eating habits in Greenland and provides much better information for patients. The review provided a snapshot of the quality of colonoscopies in Greenland, highlighting the necessity to continue this process to ensure that the quality is up to standard. Furthermore, SCE helps reduce the environmental footprint of gastrointestinal endoscopy by avoiding the need for patient air transport; instead of 77 round trips (61,830 km), only 8 (6440 km) were required.

Challenges of circulatory unstable pelvic fracture in Greenland.

Management of circulatory unstable pelvic fracture in Greenland - from a remote village to Level 1 Trauma center. This case report depicts the transportation of an unstable patient in a rural area, where transportation of the critically ill patient is inherently difficult due to infrastructure. The case report brings knowledge to the reader of logistic conditions in Greenland, which differ greatly from those in Denmark. Furthermore, it highlights the importance of knowledge of damage control surgery and of great intercollegiate cooperation.

Development and prevention of ischemic contracture ("stone heart") in the pig heart.

Stone heart (ischemic contracture) is a rare and serious condition observed in the heart after periods of warm ischemia. The underlying mechanisms are largely unknown and treatment options are lacking. In view of the possibilities for cardiac donation after circulatory death (DCD), introducing risks for ischemic damage, we have investigated stone heart in pigs. Following cessation of ventilation, circulatory death (systolic pressure <8 mmHg) occurred within 13.1 ± 1.2 min; and a stone heart, manifested with asystole, increased left ventricular wall thickness and stiffness, established after a further 17 ± 6 min. Adenosine triphosphate and phosphocreatine levels decreased by about 50% in the stone heart. Electron microscopy showed deteriorated structure with contraction bands, Z-line streaming and swollen mitochondria. Synchrotron based small angle X-ray scattering of trabecular samples from stone hearts revealed attachment of myosin to actin, without volume changes in the sarcomeres. Ca2+ sensitivity, determined in permeabilized muscle, was increased in stone heart samples. An in vitro model for stone heart, using isolated trabecular muscle exposed to hypoxia/zero glucose, exhibited the main characteristics of stone heart in whole animals, with a fall in high-energy phosphates and development of muscle contracture. The stone heart condition in vitro was significantly attenuated by the myosin inhibitor MYK-461 (Mavacamten). In conclusion, the stone heart is a hypercontracted state associated with myosin binding to actin and increased Ca2+ sensitivity. The hypercontractile state, once developed, is poorly reversible. The myosin inhibitor MYK-461, which is clinically approved for other indications, could be a promising venue for prevention.

Estimation of End-Diastole in Cardiac Spectral Doppler Using Deep Learning.

Electrocardiogram (ECG) is often used together with a spectral Doppler ultrasound to separate heart cycles by determining the end-diastole locations. However, the ECG signal is not always recorded. In such cases, the cardiac cycles can be estimated manually from the ultrasound data retrospectively. We present a deep learning-based method for automatic detection of the end-diastoles in spectral Doppler spectrograms. The method uses a combination of a convolutional neural network (CNN) for extracting features and a recurrent neural network (RNN) for modeling temporal relations. In echocardiography, there are three Doppler spectrogram modalities, continuous wave, pulsed wave, and tissue velocity Doppler. Both the training and test data sets include all three modalities. The model was tested on 643 spectrograms coming from different hospitals than in the training data set. For the purposes described in this work, a valid end-diastole detection is defined as a prediction being closer than 60 ms to the reference value. We will refer to these as true detections. Similarly, a prediction farther away is defined as nonvalid or false detections. The method automatically rejects spectrograms where the detection of an end-diastole has low confidence. When setting the algorithm to reject 1.9%, the method achieved 97.7% true detections with a mean error of 14 ms and had 2.5% false detections on the remaining spectrograms.

Real-Time Nonlocal Means-Based Despeckling.

In this paper, we propose a multiscale nonlocal means-based despeckling method for medical ultrasound. The multiscale approach leads to large computational savings and improves despeckling results over single-scale iterative approaches. We present two variants of the method. The first, denoted multiscale nonlocal means (MNLM), yields uniform robust filtering of speckle both in structured and homogeneous regions. The second, denoted unnormalized MNLM (UMNLM), is more conservative in regions of structure assuring minimal disruption of salient image details. Due to the popularity of anisotropic diffusion-based methods in the despeckling literature, we review the connection between anisotropic diffusion and iterative variants of NLM. These iterative variants in turn relate to our multiscale variant. As part of our evaluation, we conduct a simulation study making use of ground truth phantoms generated from clinical B-mode ultrasound images. We evaluate our method against a set of popular methods from the despeckling literature on both fine and coarse speckle noise. In terms of computational efficiency, our method outperforms the other considered methods. Quantitatively on simulations and on a tissue-mimicking phantom, our method is found to be competitive with the state-of-the-art. On clinical B-mode images, our method is found to effectively smooth speckle while preserving low-contrast and highly localized salient image detail.

Volume stitching in three-dimensional echocardiography: distortion analysis and extension to real time.

Three-dimensional (3D) echocardiography is challenging due to limitation of the data acquisition rate caused by the speed of sound. ECG-gated stitching of data from several cardiac cycles is a possible technique to achieve higher resolution. The aim of this work is two-fold: it is, firstly, to provide a method for real-time presentation of stitched echocardiographic images acquired over several cardiac cycles and, secondly, to demonstrate that the geometrical distortion of the images is decreased when stitching is applied to 3D ultrasonic data of the left ventricle (LV). We present a volume stitching algorithm that merges data from N consecutive heart cycles into an assembled data volume. The assembly is performed in real time, making immediate volume rendering of the full volume possible. In-vivo images acquired with this technique are presented. Through simulations with a kinematic model of the LV wall, geometrical distortion and volume estimation errors due to long image capture time was quantified for 3D recordings of the LV. Curves showing the variation throughout the cardiac cycle of the maximal geometrical distortion in the LV walls are presented, as well as curves showing the volume estimates compared with the true LV volume of the model. We conclude that real-time display of stitched 3D ultrasound data is feasible and that it is an adequate technique for increasing the volume acquisition rate at a given spatial resolution. Furthermore, the geometrical distortion decreases substantially for data with higher volume rate and, for a full scan of the LV, stitching over at least four cycles is recommended.