The goal of cholesteatoma surgery is to completely remove the disease, to restore hearing when possible, and to prevent residuals and recurrence. The prevention of recurrence is dependent on the quality of the tympanic membrane (TM) reinforcement and the reconstruction of the external auditory canal (EAC) in order to oppose a new TM retraction pocket. The prevention of residuals requires complete removal of the cholesteatoma, relying on optimal visualization of the anatomical spaces harboring the disease. The epitympanum is a prime area for the development of cholesteatoma. Access can be limited with a transcanal microscopic approach, requiring an antro-mastoidectomy. The transcanal endoscopic approach offers a magnified view of this space and 0° to 45° angled endoscopes. Extensive removal of the scutum posteriorly opens a wide access to the posterior epitympanum and aditus ad antrum. Cartilaginous reconstruction of the scutum should allow excellent stability of the cartilaginous grafts and seal with the tympanal bone to prevent further pars flaccida retraction. This extensive reconstruction procedure, however, remains difficult in a one-handed endoscopic technique. Obliteration of the mastoid, sometimes associated with the epitympanum in microscopic cholesteatoma surgery is thought to bring about a reduction in the rate of recidivism (residuals and recurrences). Their application to endoscopic surgery has so far never been reported. This case presents a transcanal endoscopic procedure for cholesteatoma with epitympanic obliteration using bioglass. A transcanal endoscopic approach was performed with the aim of removing an epitympanic cholesteatoma (Fig. 1) without the transmastoid approach, and to reconstruct the scutum after obliteration of the epitympanum at the same time. The preoperative temporal bone CT scan revealed an anterior and posterior epitympanic cholesteatoma without extension into the antrum, a sclerotic mastoid, an overhang of the sigmoid sinus, and a bone erosion of the anterior tegmen tympani (Fig. 2). Rigid 0° and 45° angled, 14 mm long, 3 mm diameter endoscopes were used and coupled with a high-definition 3CCD camera and video system. Bone removal from the scutum was adapted to the extension of the cholesteatoma and performed by an underwater endoscopic drilling. Total obliteration of the epitympanum was achieved using 45S5 Bioactive Glass (Glassbone Injectable Putty, Noraker, Villeurbane, France). Perichondrium was placed to seal off the aditus ad antrum and to prevent possible migration of the Glassbone inside the mastoid, which could secondarily lead to a reduction in the volume of the epitympanic obliteration and a retraction of the cartilages. Moreover, this material must be carefully packed to avoid any cavities within the obliteration. The Glassbone was positioned from the anterior epitympanum to the aditus ad antrum, without bulging in the EAC to prevent any postoperative stenosis. Reconstruction of the scutum was performed using cartilaginous and perichondrium grafts harvested from the tragus and covering the entire surface of the obliteration. The grafts were placed paying particular attention to the sealing between them to avoid any leakage of the Glassbone in the ear canal and to prevent any secondary retraction of the grafts. An ossiculoplasty was performed using a cartilaginous piece between the stapes and the TM. No intraoperative intravenous antibiotic therapy was given. The patient was sent home the day of surgery with a prescription of local antibiotics (ofloxacin drops) for 10 days. The study has been performed according to the Declaration of Helsinki (Video S1). No pre- or postoperative complication occurred. The texture of the 45S5 Bioactive Glass was well-suited for the epitympanic obliteration using a one-handed endoscopic technique. The healing of the EAC was complete without leakage of the Glassbone. After 1 postoperative year, the patient had a self-cleaning intact ear canal, without stenosis (Fig. 3). The first diffusion-weighted imaging (DWI) magnetic resonance imaging (MRI) performed at 1 post-operative year was negative. Closed technique cholesteatoma surgery is thought to improve the postoperative quality of life of patients. More respectful of the ear anatomy, this approach could nevertheless increase the risk of residual cholesteatoma. Mastoid and epitympanic obliteration during microscopic procedures could reduce the rate of recidivism (residual and recurrence) of cholesteatoma. The procedure described in this video combines the value of transcanal endoscopy with that of epitympanic obliteration in cholesteatoma surgery. Complete visualization of the cholesteatoma is crucial for preventing residuals. The transcanal microscopic approach, even with large atticotomy,1 may be limited in the case of posterior extension to the aditus ad antrum. The antromastoidectomy provides access to the posterior epitympanum. This closed technique approach could nevertheless be difficult or even dangerous for neighboring anatomical structures in the event of a sclerotic mastoid and/or a prominent sigmoid sinus. It also requires removal of healthy bone and healthy mucosa of the mastoid. Transcanal endoscopic ear surgery (TEES) uses the magnified vision of 0° endoscopes. Removal of the scutum allows a wide visualization of the epitympanum, becoming a cul-de-sac of the EAC.2 Visualization of the posterior epitympanum is further improved by the use of 45° endoscopes. Difficulties in reconstructing the scutum after an enlarged transcanal endoscopic atticotomy may be a limiting factor in the removal of cholesteatoma in favor of a transmastoid microscopic approach. The epitympanic obliteration procedure reported in this video offers immediate benefits by facilitating the scutum reconstruction procedure. The material used constitutes a solid support for the cartilaginous grafts, without the risk of grafts tipping intraoperatively in an empty epitympanum. This is especially true as the atticotomy is large. The posterior limit of the TEES usually described at the level of the dome of the lateral semicircular canal can thus be pushed back and adapted to the extension of the cholesteatoma. A technique by endoscopic transcanal modified canal wall-down mastoidectomy has already been reported.3 This widened access allows better quality of excision of the cholesteatoma. It could thus help reduce the risk of residuals. Usually, without epitympanic obliteration, reinforcement of the pars flaccida and reconstruction of the EAC should prevent the pars flaccida retraction into the epitympanum under the effect of the negative pressure generated by the blockage of the ventilation pathways of the middle ear. The use of materials resistant to this negative pressure should prevent a new retraction pocket.1 Various techniques have been reported1: reconstruction of the scutum using cartilaginous grafts harvested from the tragus or the concha arranged in a palisade or use of cortical bone graft, use of a periosteal flap in the epitympanum to avoid medialization of the cartilages, and obliteration of the epitympanum. Our technique could help reduce the risk of cholesteatoma recurrence by preventing pars flaccida retraction. The arrangement of the grafts, in close contact with the tympanal bone is improved, reducing spaces for a new a new retraction of the pars flaccida. Obliteration also helps to prevent retraction, by mechanically occupying the volume of the epitympanic cavity without the risk of negative pressure. The limitation of this paper is that this is the report of a single case with only 1 year of follow-up. This is not possible to confirm now that this technique does prevent recurrence of cholesteatoma. These materials require criteria of biocompatibility, volume stability over time, resistance to infections, and ease of excision in the event of surgical revision.4 Autologous materials are the most commonly used.4 Muscle flaps present a risk of loss of volume and retraction of the flaps. Bone (chips or bone paté) presents a risk of loss of volume but also of secondary ossification requiring drilling in the case of surgical revision. Cartilaginous grafts arranged in a palisade are more stable in volume but limited in quantity. Synthetic materials (hydroxyapatite granules and bioactive glasses) are used in mastoid obliteration procedures. Among bioactive glasses, 45S5 Bioactive Glass (Glassbone Injectable Putty, Noraker, Villeurbane, France) is used in spine, orthopedic, and stomatological surgery due to its osteoconduction and osteostimulation properties, bacteriostatic properties, rapid availability, and ease of handling and more recently its good tolerance and safety in mastoid and epitympanic obliteration.5 The 45S5 Bioactive Glass is a material available on demand. Its consistency in the form of a paste facilitates its handling, particularly in a one-handed endoscopic technique. Short-term postoperative follow-up focuses on the quality of healing and the caliber of the EAC. In the longer term, follow-up by diffusion-weighted imaging (DWI) magnetic resonance imaging (MRI) is similar to that existing for cholesteatomas. Video S1: Transcanal endoscopic ear surgery for epitympanic cholesteatoma with obliteration using bioglass. 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