Discrimination of vocal folds lesions by multiclass classification using autofluorescence spectroscopy: An ex vivo study.

BACKGROUND: Autofluorescence spectroscopy is effective for noninvasive detection but underutilized in tissue with various pathology analyses. This study evaluates whether AFS can be used to discriminate between different types of laryngeal lesions in view of assisting in vocal fold surgery and preoperative investigations. METHODS: A total of 1308 spectra were recorded from 29 vocal fold samples obtained from 23 patients. Multiclass analysis was performed on the spectral data, categorizing lesions into normal, benign, dysplastic, or carcinoma. RESULTS: Through an appropriate selection of spectral components and a cascading classification approach based on artificial neural networks, a classification rate of 97% was achieved for each lesion class, compared to 52% using autofluorescence intensity. CONCLUSIONS: The ex vivo study demonstrates the effectiveness of AFS combined with multivariate analysis for accurate classification of vocal fold lesions. Comprehensive analysis of spectral data significantly improves classification accuracy, such as distinguishing malignant from precancerous or benign lesions.

High-fidelity glass micro-axicons fabricated by laser-assisted wet etching.

We report on the fabrication of micro-axicons made of glass by laser-assisted wet etching (LAE) and laser polishing. The employed technique, relying on a direct-writing process using a femtosecond laser, allows revealing high fidelity profiles when the exposed glass samples are etched in a heated potassium hydroxide (KOH) solution. The remaining surface roughness is then decreased by carbon dioxide (CO2) laser polishing. Such polishing is limited to the superficial layer of the component so that the tip is only slightly rounded, with a radius of curvature of nearly 200 µm. It is then shown with 500 µm-diameter axicons that a quasi-Bessel beam is generated closely after the tip and features a 5.3 µm diameter maintained over a propagation distance of almost 3.5 mm.

µRALP and Beyond: Micro-Technologies and Systems for Robot-Assisted Endoscopic Laser Microsurgery.

Laser microsurgery is the current gold standard surgical technique for the treatment of selected diseases in delicate organs such as the larynx. However, the operations require large surgical expertise and dexterity, and face significant limitations imposed by available technology, such as the requirement for direct line of sight to the surgical field, restricted access, and direct manual control of the surgical instruments. To change this status quo, the European project µRALP pioneered research towards a complete redesign of current laser microsurgery systems, focusing on the development of robotic micro-technologies to enable endoscopic operations. This has fostered awareness and interest in this field, which presents a unique set of needs, requirements and constraints, leading to research and technological developments beyond µRALP and its research consortium. This paper reviews the achievements and key contributions of such research, providing an overview of the current state of the art in robot-assisted endoscopic laser microsurgery. The primary target application considered is phonomicrosurgery, which is a representative use case involving highly challenging microsurgical techniques for the treatment of glottic diseases. The paper starts by presenting the motivations and rationale for endoscopic laser microsurgery, which leads to the introduction of robotics as an enabling technology for improved surgical field accessibility, visualization and management. Then, research goals, achievements, and current state of different technologies that can build-up to an effective robotic system for endoscopic laser microsurgery are presented. This includes research in micro-robotic laser steering, flexible robotic endoscopes, augmented imaging, assistive surgeon-robot interfaces, and cognitive surgical systems. Innovations in each of these areas are shown to provide sizable progress towards more precise, safer and higher quality endoscopic laser microsurgeries. Yet, major impact is really expected from the full integration of such individual contributions into a complete clinical surgical robotic system, as illustrated in the end of this paper with a description of preliminary cadaver trials conducted with the integrated µRALP system. Overall, the contribution of this paper lays in outlining the current state of the art and open challenges in the area of robot-assisted endoscopic laser microsurgery, which has important clinical applications even beyond laryngology.

New Compartmental Reading Method for MRI Enables Accurate Localization of Cholesteatomas With High Sensitivity and Specificity.

OBJECTIVES: Cholesteatoma is an inflammatory disease, frequently observed in childrens and young adults, with a risk of relapse or recurrence. The few studies which analyzed cholesteatoma localization on magnetic resonance imaging (MRI) usually merged CT-MR images or relied on their authors' anatomical knowledge. We propose a compartmental reading method of the compartments of the middle ear cavity for an accurate localization of cholesteatomas on MR images alone. MATERIAL AND METHODS: Our method uses easily recognizable anatomical landmarks, seen on both computed tomography (CT) and MRI, to delimit the middle ear compartments (epitympanum, mesotympanum, hypotympanum, retrotympanum, protympanum, antrum-mastoid cavity). We first tested it on 50 patients on non-enhanced temporal bone CT. Then, we evaluated its performances for the localization of cholesteatomas on MRI, compared with surgery on 31 patients (validation cohort). RESULTS: The selected anatomical landmarks that delimited the middle ear compartments were applicable in 98 to 100% of the cases. In the validation cohort, we were able to accurately localize the cholesteatoma on MRI in 83% of the cases (n = 26) with high sensitivity (95.7%) and specificity (98.6%). CONCLUSION: With our compartmental reading method, based on the recognition of well-known anatomical landmarks to differentiate the compartments of the middle ear cavity on MRI, we were able to accurately localize the cholesteatoma with high (>90%) sensitivity and specificity. Such landmarks are widely applicable and only require limited learning time based on key images. Accurate localization of the cholesteatoma is useful for the choice of surgical approach.

Comparison of Noninvasive Imagery Methods to Observe Healthy and Degenerated Olfactory Epithelium in Mice for the Early Diagnosis of Neurodegenerative Diseases.

Olfactory dysfunction could be an early and reliable indicator for the diagnosis of neurodegenerative disorders such as Alzheimer and Parkinson's diseases. In this paper, we compare the potential of different noninvasive medical imaging modalities (optical coherence tomography, confocal microscopy, and fluorescence endomicroscopy) to distinguish how the olfactory epithelium, both at the cellular and the structural levels, is altered. Investigations were carried out on three experimental groups: two pathological groups (mice models with deliberately altered olfactory epithelium and Alzheimer's disease transgenic mice models) were compared with healthy mice models. As histological staining, the three tested noninvasive imaging tools demonstrated the general tubular organization of the olfactory epithelium on healthy mice. Contrary to OCT, confocal microscopy, and endomicroscopy allowed visualizing the inner structure of olfactory epithelium as well as its morphological or functional changes on pathological models, alterations classically observed with histological assessment. The results could lead to relevant development of imaging tools for noninvasive and early diagnosis of neurodegenerative diseases through the in situ characterization of the olfactory epithelium.

Audiometric Results of Stapedotomy Surgery for Otoscelorsis: Influence of the Radiological Stage.

BACKGROUND: The objective of this study was to identify a correlation between the radiological stage of otosclerosis and the pre- and postoperative audiometric results of patients who underwent a stapedotomy. METHODS: Ninety-three patients with radiologically and surgically confirmed otosclerosis who underwent stapedotomy surgery and CT scanning within 18 months before the operation were included. The CT scans were interpreted by an otologist and a specialised radiologist to determine their radiological stage according to the classification of Veillon and Fraysse. The patients received a pre- and postoperative audiogram in the short and long term. RESULTS: The preoperative bone conduction thresholds were higher in patients who presented with an advanced radiological stage of otosclerosis: 32.7 dB ±â€Š12.4 compared with those who presented with a less advanced radiological stage: 24.3 dB ±â€Š10.0. The preoperative air conduction thresholds were higher in patients who presented with an impairment of the round window: 58.1 dB ±â€Š13.5 compared with those who presented with no impairment of the round window: 48.7 dB ±â€Š14.5. The postoperative improvement in the air-bone gap was significantly higher for the localised foci: 16.9 dB ±â€Š8.6 versus 11.0 dB ±â€Š9.2, but only in the short term. CONCLUSION: There was a clinical radiological correlation with the preoperative results: In BC, there was a correlation with the radiological stage of Veillon and in AC, there was a correlation with impairment of the round window. The link between the radiological stage of otosclerosis and the postoperative audiometric results is less obvious. In the short term, the audiometric improvements in the air-bone gap were greater in patients in the early stages according to the Veillon classification, but this result was not sustained in the long-term.

Transcutaneous Baha Attract system: Long-term outcomes of the French multicenter study.

BACKGROUND: Bone conduction implants based on abutment-driven acoustic transmission result in good hearing outcomes; however, skin complications impact the quality of life (QOL) and possibly the viability of the device for many patients. The transcutaneous magnetic Baha® Attract technology was developed with the goal of minimising skin complications. OBJECTIVES: To analyse surgical, auditory and QOL outcomes for patients implanted with the Baha® Attract. DESIGN: Prospective multicentre cohort study. SETTING: Four French tertiary referral centres. PARTICIPANTS: Thirty-two patients implanted with the Baha® Attract, including 25 with conductive and mixed hearing loss and 7 with single-sided deafness. MAIN OUTCOME MEASURES: Postoperative follow-up involved the visual analysis of soft tissue adaptation and sound processor magnet strength measurement. The audiometric outcomes were evaluated in quiet and noise, and the QOL was assessed using three different questionnaires. RESULTS: After 12 months of use, soft tissue was thinner, and mean magnet strength was significantly decreased (3.7-3.1, P < 0.05) relative to measures during surgery. The speech recognition threshold in quiet significantly improved compared to unaided situation (73-44 dB HL respectively, P < 0.001) as did functional gain in noise (+2.8). All QOL scores improved, and the APHAB questionnaire score correlated with the audiometric outcomes. CONCLUSIONS: The Baha® Attract technology results in significant hearing gain and improves QOL. Skin complications were not observed, although surgeons, audiologists and patients should be aware of soft tissue evolution during the first postoperative year. The reversibility of this implant is a major advantage that allows switching to another system if hearing degrades.

Review on Otological Robotic Systems: Toward Microrobot-Assisted Cholesteatoma Surgery.

Otologic surgical procedures over time have become minimally invasive due to the development of medicine, microtechniques, and robotics. This trend then provides an expected reduction in the patient's recovery time and improvement in the accuracy of diagnosis and treatment. One of the most challenging difficulties that such techniques face are precise control of the instrument and supply of an ergonomic system to the surgeon. The objective of this literature review is to present requirements and guidelines for a surgical robotic system dedicated to middle ear surgery. This review is particularly focused on cholesteatoma surgery (diagnosis and surgical tools), which is one of the most frequent pathologies that urge for an enhanced treatment. This review also presents the current robotic systems that are implemented for otologic applications.

In Vivo Inspection of the Olfactory Epithelium: Feasibility of Robotized Optical Biopsy.

Inspecting the olfactory cleft can be of high interest, as it is an open access to neurons, and thus an opportunity to collect in situ related data in a non-invasive way. Also, recent studies show a strong link between olfactory deficiency and neurodegenerative diseases such as Alzheimer and Parkinson diseases. However, no inspection of this area is possible today, as it is very difficult to access. Only robot-assisted interventions seem viable to provide the required dexterity. The feasibility of this approach is demonstrated in this article, which shows that the path complexity to the olfactory cleft can be managed with a concentric tube robot (CTR), a particular type of continuum robot. First, new anatomical data are elaborated, in particular for the olfactory cleft, that remains hardly characterized. 3D reconstructions are conducted on the database of 20 subjects, using CT scan images. Measurements are performed to describe the anatomy, including metrics with inter-subject variability. Then, the existence of collision-free passageways for CTR is shown using the 3D reconstructions. Among the 20 subjects, 19 can be inspected using only 3 different robot geometries. This constitutes an essential step towards a robotic device to inspect subjects for clinical purposes.

Primitive Squamous Cell Carcinoma of Pterygopalatine Fossa.

Primitive tumors of pterygopalatine fossa (PPF) are often benign tumors or extension of a malignant sinonasal tract. Primitive tumors may rarely occur in PPF.The authors present a 71-year-old woman with a 6-month history of left cranial nerve palsy. Magnetic resonance imaging and positron emission tomography-computed tomography showed an enhancing isolated lesion at the PPF. A transmaxillary biopsy was performed, leading to diagnosis of primitive squamous cell carcinoma. The patient underwent radiotherapy treatment.Primitive tumors of PPF are rare and diagnosis may be difficult. Endoscopic access for diagnosis can be performed. Squamous cell carcinoma occurring in PPF is associated with poor prognosis.

Propofol-remifentanil anesthesia for upper airway endoscopy in spontaneous breathing patients: the ENDOTANIL Randomized Trial.

BACKGROUND: The ENDOTANIL Trial aimed at comparing an association of target-controlled infusion (TCI) of remifentanil and propofol to TCI of propofol alone on the clinical conditions during pan endoscopy for assessment of the upper airway (pan endoscopy) performed under tubeless general anesthesia. METHODS: This double-blind, single center, parallel, randomized, placebo-controlled trial was conducted in a French tertiary level of care, from June 2009 to February 2013. Patients scheduled for elective pan endoscopy were anesthetized using propofol TCI combined to either remifentanil TCI (effect-site concentration=1.5 ng.mL-1; remifentanil group) or placebo (control group). The main outcome measure was the percentage of clinically acceptable conditions for pan endoscopy, using a 5-criteria score (ease of laryngoscopy, position and movements of the vocal cords, cough and movements of the limbs to stimulation). The secondary outcomes were hemodynamic and respiratory safety. RESULTS: In this study 218 patients (mean±SD age 60 [10] yrs) were included. Clinically acceptable conditions were observed in 68% and 64% of the patients included in Remifentanil and Control group, respectively (P=0.39). None of the 5 parameters of the pan endoscopy score was significantly different between the 2 groups. Hemodynamic alterations were significantly lower in the Remifentanil as compared to the control group. Incidence of hypoxemia or need for rescue mechanical ventilation did not significantly differ between the 2 groups. CONCLUSIONS: The adjunction of remifentanil to propofol TCI, at a dose that maintain spontaneous breathing, did not improve the conditions for pan endoscopy, but attenuates the hemodynamic response induced by upper airway stimulation.

Alcohol percutaneous neurolysis of the sphenopalatine ganglion in the management of refractory cranio-facial pain.

INTRODUCTION: The sphenopalatine ganglion (SPN) has been proven to be involved in various types of facial pain syndromes. Management of these cranio-facial pain syndromes can be challenging, and existing specific treatments are sometimes inefficient and may fail. The purpose of this study is to describe and evaluate alcohol SPN in the management of cranio-facial pain. METHODS: Forty-two patients suffering from refractory facial pain who underwent 58 consecutive SPN were included in this study between 2000 and 2013. Patients were divided into three groups: group "cluster headache" (CH), group "persistent idiopathic facial pain" (PFIP), and group "Other". Pain was assessed using Visual Analogue Scale scores (measured immediately before and after procedure and at regular intervals following the procedure). Alcohol SPN was considered to be effective when pain relief was equal to or greater than 50 % and lasting for at least 1 month. All procedures were realized ambulatory under CT guidance and consisted of an injection of 1 ml of absolute alcohol. RESULTS: Overall efficacy rate of alcohol SPN was 67.2 %, with mean pain relief duration of 10.3 months. Procedure was graded either not painful or tolerable by patients in 64.2 %. Analysis showed a higher efficacy rate in the groups CH (76.5 %) and PFIP (85.7 %) compared to the group Other (40 %). No difference was found between groups regarding the recurrence rate. CONCLUSION: Alcohol SPN under CT guidance appears as a safe and effective treatment of refractory facial pain, especially in cases of cluster headache and persistent idiopathic facial pain.

Double skull base defects with primary spontaneous cerebrospinal fluid leaks in a single patient: temporal and sphenoid bones.

Primary spontaneous cerebrospinal fluid leaks occurring in the absence of any apparent cause are rare. Patients may present such leaks simultaneously, or successively, in multiple locations. We report here the sixth case of anterior and lateral skull base defects presented in a single patient. Although rhinoliquorrhea and otoliquorrhea were reported separately in the literature, we postulated that the pathophysiology is the same for the whole skull base; obesity seems to contribute to the development of such primary spontaneous cerebrospinal fluid leak. Consequently, management is similar and regular follow-up is very important.

Newborn hearing screening on infants at risk.

OBJECTIVES: This article presents the results of newborn hearing screenings on infants at risk of hearing impairment at the French University Hospital of Besançon from 2001 to 2007. MATERIALS AND METHODS: All newborns at risk of hearing impairment were tested according to the method recommended by the Joint Committee on Infant Hearing (JCIH): a two-step automated oto-acoustic emissions (AOAE) program, completed by an auditory brainstem response (ABR) for the positive diagnosis of hearing impairment. The screening started with AOAE on the third day of life, at the earliest. If one or both ears did not have AOAE, the infant was re-tested at which time, should the AOAE again be positive, ABR was performed. When the ABR threshold was 40dB or more, the infant was referred to an audiologist specialized in infant deafness for diagnosis confirmation and management. RESULTS: Over the period, 1461 infants were screened, among whom 4.55% were diagnosed as deaf or hard of hearing. Nearly 10% of the infants were lost to follow up. Forty-six children had a sensorineural hearing impairment, of which 34 were bilateral and were managed before the age of 6 months. The risk factors for sensorineural hearing loss were (in order of statistical significance): severe birth asphyxia; neurological disorder; syndromes known to be associated with hearing loss; TORCH (toxoplasmosis, rubella, cytomegalovirus, herpes) infections; family history of deafness; age at the time of screening; and the association of 2 or more risk factors. However, birth weight inferior to 1500g and premature birth before the 34th week of pregnancy did not show a statistically significant influence on sensorineural hearing loss. Craniofacial anomalies (mostly cleft palate and ear aplasia) were a significant factor for conductive hearing loss. CONCLUSION: Our selected hearing screening on infants at risk allowed 60 deaf children access to early management. However, too many children were lost to follow up; which revealed that better information regarding risk of hearing loss must be provided to parents and paramedics and universal newborn screening needs to be performed. The most important result of this study is that in a population of hearing impaired children, with an impairment incidence close to what is commonly reported, the association of several risk factors proves to be a significant additional risk factor for hearing impairment.

[Home accidents associated with anosmia]. / Accidents domestiques chez 57 patients ayant une perte sévère de l'odorat.

OBJECTIVE: To assess the risk of home accidents related to severe hyposmia. METHODS: A questionnaire, completed by 57 hyposmic patients and 49 control subjects with a normal sense of smell, asked about four specific types of olfactory-related home accidents: undetected fires, undetected gas leaks, consumption of spoiled food, and incidents of food burning. Level of olfactory function was determined by olfactory testing (Biolfa). RESULTS: Olfactory testing revealed that 60% of the patients were anosmic and 40% had severe hyposmia. They reported cooking-related accidents most often (63%), followed by eating spoiled food (51%), inability to detect a gas leak (47%) and inability to smell a fire (26%). All these accidents were significantly more frequent than in the control population (p<10(-4)). DISCUSSION AND CONCLUSION: This paper, the first in the European literature and the second in the international literature, shows that patients with severely impaired olfaction are more likely to experience related accidents than those with normal olfactory function.

Evaluation of combined medical and surgical treatment in nasal polyposis - III. Correlation between symptoms and CT scores before and after surgery for nasal polyposis.

CONCLUSION: Computed tomography (CT) in nasal polyposis (NP) patients has three functions before any treatment. CT provides objective evidence of the disease and precise topography of the disease, and is an indicator of the disease severity. After functional endoscopic sinus surgery (FESS), CT is an indicator of the residual disease severity and permits detection of asymptomatic mucoceles. OBJECTIVE: NP affects nearly 4% of the population. CT has become the examination of choice for the exploration of NP. FESS is accepted for NP treatment in the setting of failure of medical management. The aim of this study was to find out whether any correlation exists between symptom severity and CT scan score before and after FESS. PATIENTS AND METHODS: A total of 114 CT scans were performed in NP patients without contrast medium before and after FESS (mean follow-up 5 years), and were scored according to the Lund-MacKay system. RESULTS: Lund-MacKay scores before treatment ranged from 8 to 24. There was a correlation between symptom and CT scores before any treatment. Postoperative Lund-MacKay scores ranged from 0 to 24. There was a correlation between symptom and CT scores after surgery. There was no correlation between postoperative symptom and baseline CT scores. Eleven asymptomatic mucoceles were found.