[Interactive intraoperative annotation of surgical landmarks in student education to support learning efficiency and motivation]. / Interaktive intraoperative Annotation chirurgischer Anatomie in der studentischen Ausbildung zur Unterstützung der Lerneffizienz und -motivation.

BACKGROUND: The development of technological innovations has not only changed social life and the healthcare system, but also affects medical education. The aim of this pilot study was to evaluate whether students, when observing a microsurgical procedure of the temporal bone, gain an additional understanding of the anatomical structures and surgical site when visualization is used that provides identical views for the surgeon and viewer in 3D. MATERIALS AND METHODS: During regular attendance tutorials, students were randomly assigned to three different groups: control group, 2D group, or 3D group. Evaluation questionnaires and intraoperative student annotation of the surgical view were used to assess the subjective didactic value of different visualization formats and resultant learning experiences for the students. RESULTS: A total of 47 students were included in the investigations during conventional attendance tutorials. The majority indicated a high added value of the 3D visualization in terms of method (70%) and vividness (80%) compared to the 2D group and self-study; 69% of the students fully agreed with the statement that 2D and 3D visualization increases learning motivation and is a very good way to improve recognition of anatomical topography and structures. CONCLUSION: New interactive visualization options in teaching promote learning efficiency and motivation among students. Especially 3D visualization and intraoperative annotation of the surgical view by the student is a useful didactic tool and increases the quality of clinical teaching. It supports the perception of anatomical topography and enables more focused surgical training.

Evaluating the didactic value of 3D visualization in otosurgery.

INTRODUCTION: Improvements of surgical visualization add value to the quality of clinical routine and offer the opportunity to improve surgical education of medical staff. The aim of this study was to determine whether otorhinolaryngology trainees gain additional comprehension of the anatomical structures and the surgical site when 3D visualization is used. METHODS: Data were collected from ENT trainees of microsurgical courses of the middle ear, inner ear and lateral skull base at four university ENT departments (Charité (Berlin), Martin Luther University Halle-Wittenberg (Halle/Saale), Ludwig Maximilian University (Munich) and Rostock University Medical Center). Participants were asked to complete a questionnaire assessing the subjective value of identical surgical field visualization in 3D for surgeon and observer. RESULTS: A total of 112 participants completed the questionnaire. The majority of participants stated a high additional value of 3D visualization compared to 2D visualization, with 75% fully agreeing to the statement that 3D visualization of the surgical field is superior to perceive the anatomical topography and structures compared to 2D representation. Participants encouraged the storage of data in online learning platforms. CONCLUSION: The results show that 3D visualization with identical imaging for surgeon and observer is a useful tool in teaching of microsurgery. It addresses perception of anatomical topography and structures as well as conception of the surgical workflow.

Air filters for indoor environments: Interlaboratory evaluation of the new international filter testing standard ISO 16890.

Electret filters are widely used in HVAC systems to decrease particulate matter in indoor environments. The previous standard in Europe for testing air filters for general ventilation was EN 779. In July 2018, it was replaced by the new international standard ISO 16890. One major change is the discharging process: It is now performed by treating the filters with saturated isopropyl alcohol (IPA) vapor. The process is intended to simulate a worst-case scenario of the filtration efficiency due to the reduction of the electret effect. These minimal efficiencies are a principal part of the filter classification. Therefore, two round robin tests with different filter classes (F9 and F7 according to EN 779) and up to eleven participants were carried out to evaluate the new test method by comparing the filtration efficiencies and pressure drops before and after the IPA treatment. Pressure drop measurements showed no mechanical altering of the material due to the discharging process. The calculated filter classes had a maximum deviation of 5%. Even with different equipment, the results indicate that the new ISO 16890 seems to be a viable test standard and a decent replacement for previous national standards.

Polydimethylsiloxane for injection laryngoplasty: two cases necessitating tracheotomy.

The surgical treatment of glottic insufficiency due to lesions of the recurrent laryngeal nerve has become a routine procedure in the last few decades. In particular, injection laryngoplasty with polydimethylsiloxane (PDMS) has proved to be an easy, effective and safe method for vocal fold medialization. It is a biologically inert substance having almost ideal properties as a filler; complications related to its intralaryngeal use such as migration, or granuloma formation are extremely rare and allergic reactions have not been reported as yet. We discuss two cases representing the first description of acute severe complications after injection laryngoplasty with PDMS.

Chronic otitis media following infection by non-O1/non-O139 Vibrio cholerae: A case report and review of the literature.

We report a case of a chronic mesotympanic otitis media with a smelly purulent secretion from both ears and recurrent otalgia over the last five years in a six-year-old girl after swimming in the German Baltic Sea. Besides Staphylococcus aureus a non-O1/non-O139 Vibrio cholerae strain could be isolated from patient samples. An antibiotic therapy with ciprofloxacin and ceftriaxone was administered followed by atticotomy combined with tympanoplasty. We conclude that V. cholerae should not be overlooked as a differential diagnosis to otitis infections, especially when patients present with extra-intestinal infections after contact with brackish- or saltwater aquatic environments.

Open Mastoid Cavity Obliteration With a High-Porosity Hydroxyapatite Ceramic Leads to High Rate of Revision Surgery and Insufficient Cavity Obliteration.

OBJECTIVE: To assess long-term results and present experience with a high-porosity hydroxyapatite ceramic for obliterating large open mastoid cavities. STUDY-DESIGN: Cross-sectional cohort study. SETTING: Tertiary academic referral center. PATIENTS: All patients who underwent tympanomastoid surgery for chronic middle ear disease or revision surgery with reduction of an open mastoid cavity using a highly porous hydroxyapatite matrix material (HMM) between May 2005 and June 2013 were assessed for eligibility. Twenty three patients (56.9 ±â€Š18.3 yr) were included. INTERVENTION: Primary middle ear surgery or revision surgery using a HMM. MAIN OUTCOME MEASURES: Pure-tone average, computed tomography (CT), and magnetic resonance imaging (MRI) to investigate osseoinduction, osseointegration and presence of cholesteatoma, current quality of life assessed by Zurich Chronic Middle Ear Inventory and change in quality of life post-intervention assessed by the Glasgow Benefit Inventory. RESULTS: Patients were reexamined after a mean follow-up period of 88.3 months (SD 21.4 mo) after obliteration of the open mastoid cavity with HMM. Compared with visit 1, patients showed a significantly reduced ABG at visit 2 (29.22 dB ±â€Š2.71 dB versus 12.77 dB ±â€Š3.46 dB).CT scan was carried out in 21 patients (91%) patients and 17 patients (74%) underwent MRI.Revision surgery was required in a total of 17 cases (74%). In four patients recurrent cholesteatoma was found at follow up. CONCLUSIONS: Poor cavity obliteration, a high rate of revision surgery and difficult differentiation between recurrent cholesteatoma and granulation tissue in CT scan was observed.

Aural and nasal foreign bodies in children - Epidemiology and correlation with hyperkinetic disorders, developmental disorders and congenital malformations.

OBJECTIVES: Foreign body incorporation in children is often a serious situation. Attention deficit hyperactivity disorder (ADHD) could be a risk factor for self-insertion of foreign bodies. Large cohort analyses are missing. METHODS: This was a retrospective analysis of patients' records from a health insurance company representing 2.19% of the German population and 1.75% of German children and adolescents. According to the International Classification of Diseases, children in the age range between 1 and 18 years have been screened for foreign bodies in ear, nasal sinus and nostrils as well as for hyperkinetic disorders (F90), disorders of psychological development (F80-F89), and congenital malformations, deformations and chromosomal abnormalities (Q00-Q99). RESULTS: In total, 12887 children (6609 male; 6278 female) have been treated in 16929 cases. The majority (n = 10041 (77.9%)) presented with foreign body incorporation on a single occasion. On average, 1.31 cases of foreign body treatment were recorded per child; 14.1% of children with foreign body treatment (FBT) also had a record of hyperkinetic disorder, 52.7% had a disorder of psychological development, and 50.8% a congenital malformation. Mean occurrence of FBT was 174.8 days before the diagnosis of a hyperkinetic disorder but 517.2 days after the diagnosis of a psychological development disorder and 683.1 days after the diagnosis of a congenital malformation, deformation or chromosomal abnormality. CONCLUSION: Patients with disorders of psychological development as well as children with congenital malformations are high-risk patients for nasal and aural foreign bodies. The prevalence of a hyperkinetic disorder in patients with FBT is much higher than in the normal population. ADHD is a risk factor for foreign bodies.

Microbiome and Culture Based Analysis of Chronic Rhinosinusitis Compared to Healthy Sinus Mucosa.

The role of bacteria in chronic rhinosinusitis (CRS) is still not well understood. Whole microbiome analysis adds new aspects to our current understanding that is mainly based on isolated bacteria. It is still unclear how the results of microbiome analysis and the classical culture based approaches interrelate. To address this, middle meatus swabs and tissue samples were obtained during sinus surgery in 5 patients with CRS with nasal polyps (CRSwNP), 5 patients with diffuse CRS without nasal polyps (CRSsNP), 5 patients with unilateral purulent maxillary CRS (upm CRS) and 3 patients with healthy sinus mucosa. Swabs were cultured, and associated bacteria were identified. Additionally, parts of each tissue sample also underwent culture approaches, and in parallel DNA was extracted for 16S rRNA gene amplicon-based microbiome analysis. From tissue samples 4.2 ± 1.2 distinct species per patient were cultured, from swabs 5.4 ± 1.6. The most frequently cultured species from the swabs were Propionibacterium acnes, Staphylococcus epidermidis, Corynebacterium spp. and Staphylococcus aureus. The 16S-RNA gene analysis revealed no clear differentiation of the bacterial community of healthy compared to CRS samples of unilateral purulent maxillary CRS and CRSwNP. However, the bacterial community of CRSsNP differed significantly from the healthy controls. In the CRSsNP samples Flavobacterium, Pseudomonas, Pedobacter, Porphyromonas, Stenotrophomonas, and Brevundimonas were significantly enriched compared to the healthy controls. Species isolated from culture did not generally correspond with the most abundant genera in microbiome analysis. Only Fusobacteria, Parvimonas, and Prevotella found in 2 unilateral purulent maxillary CRS samples by the cultivation dependent approach were also found in the cultivation independent approach in high abundance, suggesting a classic infectious pathogenesis of odontogenic origin in these two specific cases. Alterations of the bacterial community might be a more crucial factor for the development of CRSsNP compared to CRSwNP. Further studies are needed to investigate the relation between bacterial community characteristics and the development of CRSsNP.

Sevoflurane at 1.0 MAC together with remifentanil and propofol produces clinically acceptable intubation conditions at the vocal cords: A prospective randomized study.

Objective The overall intubation conditions after tracheal intubation with remifentanil, propofol, and sevoflurane at 1.0 minimum alveolar concentration (MAC) are worse than with rocuronium at 0.45 mg/kg. Therefore, we compared the intubation conditions and laryngeal morbidity (vocal cord injuries, hoarseness, and sore throat) with sevoflurane at 1.2 and 1.4 MAC versus 1.0 MAC. Methods In this prospective clinical trial, 90 patients were randomized to 3 groups: the sevoflurane 1.0, 1.2, and 1.4 MAC groups. At 3 min, tracheal intubation was performed and the patients' intubation conditions were assessed. The vocal cords were examined for injury by videolaryngoscopy. Additionally, the incidence and severity of laryngeal morbidity were compared between women and men. Results Acceptable intubation conditions were seen in 72% of the patients without significant differences between the groups. Overall, vocal cord injuries (oedema) occurred in three (4%) patients. Women reported sore throat more often than men (51% vs. 21%, respectively). Conclusions Intubation conditions were not improved with higher sevoflurane concentrations. The incidence and severity of sore throat were greater in women than men. TRIAL REGISTRATION: ClinicalTrials.Gov: NCT 01896245.

Positioning Accuracy in Otosurgery Measured with Optical Tracking.

OBJECTIVES: To assess positioning accuracy in otosurgery and to test the impact of the two-handed instrument holding technique and the instrument support technique on surgical precision. To test an otologic training model with optical tracking. STUDY DESIGN: In total, 14 ENT surgeons in the same department with different levels of surgical experience performed static and dynamic tasks with otologic microinstruments under simulated otosurgical conditions. METHODS: Tip motion of the microinstrument was registered in three dimensions by optical tracking during 10 different tasks simulating surgical steps such as prosthesis crimping and dissection of the middle ear using formalin-fixed temporal bone. Instrument marker trajectories were compared within groups of experienced and less experienced surgeons performing uncompensated or compensated exercises. RESULTS: Experienced surgeons have significantly better positioning accuracy than novice ear surgeons in terms of mean displacement values of marker trajectories. The instrument support and the two-handed instrument holding techniques significantly reduce surgeons' tremor. The laboratory set-up presented in this study provides precise feedback for otosurgeons about their surgical skills and proved to be a useful device for otosurgical training. CONCLUSIONS: Simple tremor compensation techniques may offer trainees the potential to improve their positioning accuracy to the level of more experienced surgeons. Training in an experimental otologic environment with optical tracking may aid acquisition of technical skills in middle ear surgery and potentially shorten the learning curve. Thus, simulated exercises of surgical steps should be integrated into the training of otosurgeons.

Conservative management of post-intubation tracheal tears-report of three cases.

Iatrogenic tracheal rupture is a rare complication after intubation. We present three patients with tracheal tears. In all of these patients, a common finding was a lesion of the posterior tracheal wall with postoperative subcutaneous and emphysema as the first clinical sign of the rupture. Diagnosis and follow-up were based on clinical and endoscopic findings and chest computed tomography (CT) scans. In our cases with progressive subcutaneous and mediastinal emphysema or dyspnea, we performed a tracheotomy and bypassed the lesion with a tracheostomy tube to avoid an increase in air leakage into the mediastinum. Under broad-spectrum antibiotic therapy, no mediastinitis occurred and all patients survived without sequelae. Closure of tracheostomy was scheduled for 1-2 months after tracheal injury. Analysis of surgical and anesthesiological procedures revealed no abnormalities and the accumulation of tracheal injuries was considered as accidental. We found that in clinically stable patients with spontaneous breathing and with no mediastinitis, a conservative management of tracheal tears is a safe procedure.