Endoscopic ultrasonography and small‐bowel endoscopy: Present and future

Over the last decade, impressive technological advances have occurred in ultrasonography and small‐bowel endoscopy. Nowadays, endoscopic ultrasonography is an essential diagnostic tool and a therapeutic weapon for pancreatobiliary disorders. Capsule endoscopy and device‐assisted enteroscopy have quickly become the reference standard for the diagnosis of small‐bowel luminal diseases, thereby leading to radical changes in diagnostic and therapeutic pathways. We herein provide an up‐to‐date overview of the latest advances in endoscopic ultrasonography and small‐bowel endoscopy, focusing on the emerging paradigms and technological innovations that might improve clinical practice in the near future.     

Magnetic resonance elastography with guided pressure waves

Magnetic resonance elastography aims to non-invasively and remotely characterize the mechanical properties of living tissues. To quantitatively and regionally map the shear viscoelastic moduli in vivo, the technique must achieve proper mechanical excitation throughout the targeted tissues. Although it is straightforward, ante manibus, in close organs such as the liver or the breast, which practitioners clinically palpate already, it is somewhat fortunately highly challenging to trick the natural protective barriers of remote organs such as the brain. So far, mechanical waves have been induced in the latter by shaking the surrounding cranial bones. Here, the skull was circumvented by guiding pressure waves inside the subject's buccal cavity so mechanical waves could propagate from within through the brainstem up to the brain. Repeatable, reproducible and robust displacement fields were recorded in phantoms and in vivo by magnetic resonance elastography with guided pressure waves such that quantitative mechanical outcomes were extracted in the human brain.     

PDT in clinics: indications, results, and markets.

Photodynamic therapy (PDT) is based on the selective light activation of an exogenously given drug to patients. PDT acts mainly on cell membranes either of neovascular endothelial cells or of cancer cells leading to cancer cell death. Six drugs are now marketed based on clinical assays in various indications, which showed a clear cost efficiency as compared to other classical procedures. PDT is easy to handle and can be performed in medical installations fitting the conditions of health care in developing countries. Its cost effectiveness could represent an appropriate solution to the increasing number of cancers of various origin. However despite all the clinical results now available, PDT development remains slow. The reasons for this situation include cost of development, intellectual property, and competition between pharmaceutical companies.     

Idiopathic Headache as a Possible Risk Factor for Phantom Tooth Pain

Following tooth pulp extirpation, some subjects suffer from persistent pain which affects edentate sites in absence of any local pathology. As regards this peculiar pain, called phantom tooth pain (PTP), what is puzzling is the fact there is a low prevalence of PTP in a very large population showing identical conditions of tooth pulp extirpation. The present investigation indicates that PTP mainly affects migraine (M) and cluster headache (CH) sufferers, whereas it does not affect subjects who have a negative personal and family history for idiopathic headache (IH). These results circumscribe the presence of PTP to a specific section of the population. The present results, besides indicating that PTP may be the result of a peculiar neuronal predisposition relating to IH pathogenesis, suggests some practical therapeutic hints. In fact, successful anti- M and anti-CH prophylactic treatment greatly improve PTP syndrome.     

Continuous mixed venous oximetry in critically ill surgical patients. 'High-tech' cost-effectiveness

Mixed venous oxygen saturation (Svo2) provides a measure of cardiorespiratory ability to meet the body's needs for oxygen. The Svo2 was measured continuously in 20 critically ill surgical patients using a pulmonary-artery oximetry system. The accuracy of the technique was validated by comparing initial continuous Svo2 to the laboratory determination of Svo2. Oximetry was used to guide therapeutic decisions regarding fluid, inotropic agents, vasodilators and ventilator setting and was useful in ten cases. Sepsis developed in nine patients; this severely limited the usefulness of the technique. With clinical decision making based on oximetry, there was a savings per catheter of 2.65 cardiac output determinations and 5.9 venous blood gas determinations, resulting in a net savings per catheter of +75.     

Working memory after severe traumatic brain injury.

The aim of the present study was to assess the functioning of the different subsystems of working memory after severe traumatic brain injury (TBI). A total of 30 patients with severe chronic TBI and 28 controls received a comprehensive assessment of working memory addressing the phonological loop (forward and backward digit span; word length and phonological similarity effects), the visuospatial sketchpad (forward and backward visual spans), and the central executive (tasks requiring simultaneous storage and processing of information, dual-task processing, working memory updating). Results showed that there were only marginal group differences regarding the functioning of the two slave systems, whereas patients with severe TBI performed significantly poorer than controls on most central executive tasks, particularly on those requiring a high level of controlled processing. These results suggest that severe TBI is associated with an impairment of executive aspects of working memory. The anatomic substrate of this impairment remains to be elucidated. It might be related to a defective activation of a distributed network, including the dorsolateral prefrontal cortex.