Hereditary haemorrhagic telangiectasia: an overview from an ear, nose and throat perspective.

Patients with hereditary haemorrhagic telangiectasia can present with a multitude of symptoms caused by telangiectasia and arteriovenous malformations in the nose, brain, gastrointestinal tract, liver and spinal cord. Clinicians should be aware of the potential diagnosis of hereditary haemorrhagic telangiectasia and how to manage these patients both in the acute and chronic setting. Identifying these patients and optimising their management can help reverse the reduced life expectancy back to that of the normal population. The management of these patients is complex and often requires a multidisciplinary approach, with difficult discussions to be had around screening for arteriovenous malformations and genetic testing. The stepwise management ladder can be used in both the medical and surgical strategies; there are multiple pharmacological and surgical options available, all with their own side effects and risks. Patient education is key to help informed decision making. This article outlines the clinical characteristics of the disease and management options available.

A conserved role for Notch signaling in priming the cellular response to Shh through ciliary localisation of the key Shh transducer Smo.

Notochord-derived Sonic Hedgehog (Shh) is essential for dorsoventral patterning of the overlying neural tube. Increasing concentration and duration of Shh signal induces progenitors to acquire progressively more ventral fates. We show that Notch signalling augments the response of neuroepithelial cells to Shh, leading to the induction of higher expression levels of the Shh target gene Ptch1 and subsequently induction of more ventral cell fates. Furthermore, we demonstrate that activated Notch1 leads to pronounced accumulation of Smoothened (Smo) within primary cilia and elevated levels of full-length Gli3. Finally, we show that Notch activity promotes longer primary cilia both in vitro and in vivo. Strikingly, these Notch-regulated effects are Shh independent. These data identify Notch signalling as a novel modulator of Shh signalling that acts mechanistically via regulation of ciliary localisation of key components of its transduction machinery.

The use of ultrasound to guide time-critical cannula tracheotomy when anterior neck airway anatomy is unidentifiable.

BACKGROUND AND OBJECTIVE: Transtracheal or transcricothyroid placement of a cannula is a practice used in a number of aspects of airway management in anaesthesia and intensive care. In this study, we aimed to investigate whether the use of ultrasound will facilitate cannula placement in a time-critical situation in patients with difficult anterior neck airway anatomy. METHOD: Fifty anaesthetists were randomised to either ultrasound-guided or conventional unguided attempts, at cannula insertion into a model simulating a patient with unidentifiable anterior neck anatomy. Endpoints were the success, and time to success, of cannula placement. RESULTS: There was a significant increase in success rate (83 vs. 43%, P = 0.011) and a significant decrease in time to successful placement (median time to successful cannulation 57 vs. 110 s, P = 0.008) using ultrasound guided compared to unguided cannula placement. CONCLUSION: If a 'can't intubate, can't oxygenate' scenario occurs in a patient with unidentifiable anterior neck airway anatomy in a location where an ultrasound machine is immediately available, we recommend that consideration is given to the use of ultrasound-guided cannula tracheotomy as the first-line rescue technique.