Recently, EAONO/JOS's joint consensus paper on definitions, classification, and staging of middle ear cholesteatoma was published 1 .As it is the era of collection of and report on uniform and comparable data, this is a welcome consensus statement. Currently, we are setting up a new nationwide multicenter study in the Netherlands, entitled Dutch Cholesteatoma Data, in which we would like to implement this guideline. To inform colleagues about our local experiences and choices so far, we are writing this letter.Although the EAONO/JOS consensus statements are clearly presented, we encountered some difficulties with the classification. First, we believe that the divisions of the middle ear space need further specifications. The anatomical sites as presented in the figure and the text of the consensus statements 1 can be variously interpreted and show some "blank spots. " For instance, the borders used for the anterior epitympanic space are unclear, which, in addition to the variation in anatomy and exposition in this area (canal wall up, canal wall down, microscopic, and endoscopic), will most likely result in a non-uniform registration. Second, we strongly believe that there is a primary need to elaborate on the classification rather than simplify it with a staging system. Gathering classification data on extent, complication, and ossicular state, using an easy format will make it possible to monitor surgical outcomes. This will allow comparisons of data among different hospitals, publications, and classifications. When large numbers of data on outcomes in relation to classification become available, results can be used to propose different stages. To improve the practical applicability of the EAONO/JOS joint statement in our national study, we have proposed to our participating ENT surgeons the following modifications:1. The borders of divisions of the middle ear and mastoid are further defined, and consequently, the figure of the consensus paper is refined [1] . In the EAONO/JOS consensus statement, the middle ear and mastoid spaces are divided into four sites to classify the extent of the cholesteatoma: difficult access sites (S), tympanic cavity (T), attic (A), and mastoid and antrum (M). The difficult access sites (S) further include S1 (the supratubal recess) and S2 (the sinus tympani). We propose to define the anatomical divisions of the middle ear and mastoid in more detail using surgical and anatomical landmarks. These landmarks based on a selection of published papers on this topic are highly likely to be identified both on CT scans and during all types of surgical approaches and are thus less prone to various interpretations [2][3][4] . Table 1 summarizes our suggestions for further specification of borders between the different sites of the middle ear and mastoid. In addition, Figure 1 shows the updated illustration based on those refined borders.An advantage of a more detailed description of these borders can be illustrated by the following examples that describe the difference between A and S1 ant...

Background: To coordinate and align the content for registration of cholesteatoma care. Methods: Systematic Delphi consensus procedure, consisting three rounds: two written sessions followed by a face-to-face meeting. Before this procedure, input on important patient outcomes was obtained. Consensus was defined as at least 80% agreement by participants. Hundred-thirty-six adult patients who had undergone cholesteatoma surgery and all ENT surgeons of the Dutch ENT Society were invited. The consensus rounds were attended by ENT surgeons with cholesteatoma surgery experience. Feasibility and acceptability of outcome measures and reporting agreements were assessed in round 1 by 150 ENT surgeons. In round 2 definitions were narrowed and context information to interpret outcome measure were questioned. In round 3, the results, amendments, and the open-ended points were discussed to reach agreement. Results: Most important outcome measures are: 1) the presence or absence of a cholesteatoma in the first 5 years after surgical removal of cholesteatoma, 2) hearing level after surgical removal of cholesteatoma, and 3) the documented assessment of patient's complaints with a validated patient reported outcome measures questionnaire (PROM). Furthermore, consensus was reached on the registration of cholesteatoma type (residual/recurrent), localization of cholesteatoma, and reporting of the presence of cholesteatoma in the follow-up. Conclusion: Consensus was reached on the content and method of registration of cholesteatoma care based on patient's and ENT surgeons input. Three outcome measures were defined. National agreements on the method and content of registration will facilitate monitoring and feedback to the ENT surgeon about the cholesteatoma care.

Purpose Differences in the definition and classification of cholesteatoma hinders comparing of surgical outcomes of cholesteatoma. Uniform registration is necessary to allow investigators to share and compare their findings. For many years surgical cholesteatoma procedures were divided into two main groups: canal wall up mastoidectomy (CWU) and canal wall down mastoidectomy (CWD). Recently, mastoid obliteration can be added to both procedures. Because of great variation within these main groups, the International Otology Outcome Group (IOOG) proposed the new SAMEO-ATO classification system to categorize tympanomastoid operations. The aim of our study was to correlate the mastoid bone extirpation (M-stage) with the contemporary (CWU, CWD with or without obliteration) system. Methods Demographic characteristics and type of performed surgery were registered for 135 cholesteatoma patients from sixteen hospitals, both secondary and tertiary care institutions, across the Netherlands. In addition, the surgical reports were collected, retrospectively classified according to the contemporary system and the new system and compared. Correlations of the outcomes were calculated. Results In total, there were 112 CWU and 14 CWD (both with or without obliteration) suitable for correlation analysis. Z test for correlation between the M-stage and CWU procedure was significant for M1a and M1b procedure and significant for M2c with the CWD procedure. Conclusion The newly proposed SAMEO-ATO classification seems to be more detailed in the registration of surgical procedures than surgeons currently are used to. All M-stages of the SAMEO-ATO system are correlating well to the standard CWU and CWD except one 'in between' M-stage.

Background: Results and success measures of cholesteatoma surgery are generally described using objective data whereas subjective data are mostly lacking. Patients experiences and complaints are becoming more important alongside clinical and audiometric outcome measures in cholesteatoma care. Objective: To investigate the course of patient-reported complaints, the impact of complaints, audiometric measures and the stability of audiometric measures, and complaints over time after primary and recurrent/residual cholesteatoma surgery. Methods: Postoperative patients were prospectively included and divided into primary acquired and recurrent/residual cholesteatoma. The EuroQol 5D (EQ-5D-3L), Otology Questionnaire Amsterdam (OQUA), and the Speech Spatial Questionnaire (SSQ) were completed by 144 patients up to 2 years postoperative. Patient-reported complaints divided in eight separate domains, postoperative hearing and impact on daily life were longitudinally assessed by means of linear mixed models.Results: Hearing loss and tinnitus are the most reported postoperative complaints over time. Patient-reported loss of taste and the impact of all complaints decline over time. All other patient-reported complaints remain stable over time, only itch complaints fluctuate. Primary cholesteatoma patients score significantly higher on hearing loss complaints compared with recurrent/residual patients although they have comparable mean audiometric hearing loss. Furthermore, pure-tone hearing threshold, instead of asymmetric hearing loss, is correlated with the localization domain of the SSQ. Conclusion:This study provides important insights in the course of complaints and its impact on daily life after cholesteatoma surgery. Overall, the postoperative patientreported complaints after cholesteatoma surgery are generally low in the studied population.