Miniaturized Endoscopic 2D US Transducer for Volumetric Ultrasound Imaging of the Auditory System.

OBJECTIVE: In this paper, we focus on the carrying out and validation of minimally invasive three-dimensional (3D) ultrasound (US) imaging of the auditory system, which is based on a new miniaturized endoscopic 2D US transducer. METHODS: This unique probe consists of a 18 MHz 24 elements curved array transducer with a distal diameter of 4 mm so it can be inserted into the external auditory canal. Typical acquisition is achieved by rotating such a transducer around its own axis using a robotic platform. Reconstruction of a US volume from the set of acquired B-scans during the rotation is then performed using scan-conversion. The accuracy of the reconstruction procedure is evaluated using a dedicated phantom that includes a set of wires as reference geometry. RESULTS: Twelve acquisitions obtained from different probe poses are compared to a micro-computed tomographic model of the phantom, leading to a maximum error of 0.20 mm. Additionally, acquisitions with a cadaveric head highlight the clinical applicability of this set up. Structures of the auditory system such as the ossicles and the round window can be identified from the obtained 3D volumes. CONCLUSION: These results confirm that our technique enables the accurate imaging of the middle and inner ears without having to deteriorate the surrounding bone. SIGNIFICANCE: Since US is a real-time, wide available and non-ionizing imaging modality, our acquisition setup could facilitate the minimally invasive diagnosis and surgical navigation for otology in a fast, cost-effective and safe way.

Balloon dilation for persistent unilateral chronic obstructive Eustachian tube dysfunction is effective: a prospective multicentre study.

PURPOSE: Balloon dilatation of the Eustachian tube (BDET) is an option for treating chronic obstructive Eustachian tube dysfunction (COETD). In this prospective multicentric study, the main objective was to evaluate the results of BDET in unilateral COETD refractory to medical treatment. METHODS: Adults with unilateral COETD whose Eustachian Tube Score (ETS) was less than 5 despite medical pressure therapy were included. The primary endpoint was the change in ETS measured at 2, 6, and 12 months after BDET. Secondary objectives were the evolution of clinical symptoms assessed by the Eustachian Tube Questionnaire (ETDQ-7), audiometry, tympanometry, and otoscopy changes after BDET. RESULTS: Twenty-eight patients were included between May 2014 and December 2017 and were treated with BDET without adverse effects in three different referral centers. Population's median age was 52 (Q25; Q75: 24, 82) years. The median follow-up time was 381 (Q25; Q75: 364; 418) days. The median ETS was 2 (Q25; Q75: 1; 4) before BDET. There was a significant improvement in ETS at 2 and 6 months and 1 year after BDET (score at 1 year: 6 (Q25; Q75: 2; 8) (p < 0.0001)). There was a significant, sustained improvement in the ETDQ-7 with a score of 4.21 (Q25; Q75-3.50; 4.79) before BDET and 3.43 (Q25; Q75-2.43; 4.14) (p = 0.0012) at 1 year. There was a suggestive improvement in tympanometry results at 1 year (p = 0.025). CONCLUSION: BDET provides an improvement in symptoms and objective measures assessed at 1 year in patients with COETD who have failed medical treatment. TRIAL REGISTRATION: NCT02123277 (April 25, 2014).

Perilymph metabolomic and proteomic MALDI-ToF profiling with porous silicon chips: A proof-of-concept study.

INTRODUCTION: Sensorineural hearing losses (SNHLs) are a significant public health issue, and the hearing loss field is desperately in need of effective therapy. Pathophysiological mechanisms are not yet clearly understood in the absence of validated methods to assess the inner ear content. Proteomic and metabolomic analysis of perilymph is opening new research perspectives for SNHLs. We aimed to demonstrate the feasibility of an innovative mass spectrometry (MS) strategy using porous silicon chips (PSCs) to investigate the low molecular weight (LMW) protein and metabolite content of human perilymph. Our second objective was to stratify perilymph samples according to their MS profiles and compare these results with clinical data. MATERIAL AND METHODS: Perilymph samples obtained during cochlear implant surgery from patients with SNHLs were retrieved from a validated biobank. To focus on LMW entities, we used a PSC enrichment protocol before MALDI-ToF MS analysis. PSCs were used as a LMW molecular preanalytical stabilizer and amplifier. Patients' clinical data and SNHL characteristics were retrieved retrospectively from medical charts. RESULTS: We successfully acquired and compared 59 exploitable MS profiles out of 71 perilymph samples. There was a good correlation between duplicates. Comparing both ears from the same patient, we found good reproducibility even when there was a one-year interval between samplings. We identified three distinct groups when comparing the samples' metabolomic profiles and four homogeneous groups comparing their LMW proteome profiles. Clinical data analysis suggested that some groups shared clinical or preanalytical characteristics. CONCLUSION: This proof-of-concept study confirms that LMW proteome and metabolome content of perilymph can be analyzed with PSCs. Based on protein profiles, we managed to stratify perilymp samples according to their molecular composition. These results must be confirmed with a larger population, and sampling methods require improvement, but this approach seems promising. In the future, this approach may pave the way for companion test strategies to precisely diagnose and define potential molecular targets for audioprotective therapies.

Malnutrition and refeeding syndrome prevention in head and neck cancer patients: from theory to clinical application.

PURPOSE: The goal of this review is to raise awareness about refeeding syndrome (RFS) and to give a comprehensive presentation of recent guidelines and latest scientific data about nutritional management among head and neck cancer (HNC) patients while focusing on RFS prevention. METHODS: A review of literature for nutritional assessment and RFS management was conducted. Electronic searches of Medline, Cochrane, PubMed and Embase databases for articles published in peer-reviewed journals were conducted from February to September 2017 using the keywords: "nutrition assessment", "head and neck cancer", "refeeding syndrome" and "guidelines". Articles, reviews, book references as well as national and international guidelines in English and French were included. RESULTS: The prevalence of malnutrition is high in HNC patients and a large number of them will need artificial nutritional support or refeeding intervention. RFS is characterized by fluid and electrolyte imbalance associated with clinical manifestations induced by rapid refeeding after a period of malnutrition or starvation. Regarding risk factors for malnutrition and RFS, HNC patients are particularly vulnerable. However, RFS remains unrecognized among head and neck surgeons and medical teams. Practical data are summarized to help organizing nutritional assessment and refeeding interventions. It also summarizes preventive measures to reduce RFS incidence and morbidity in HNC population. CONCLUSION: Nutritional assessment and early refeeding interventions are crucial for HNC patients care. As prevention is the key for RFS management, early identification of patients with high risks is crucial and successful nutritional management requires a multidisciplinary approach.