No abstract

Surgical approaches to the inner ear and internal auditory canal (IAC) are well known and well documented. The objective of this study is to analyze the morphology, and surgical and anatomic findings of an exclusive endoscopic transcanal approach (EETA) to the IAC. Cadaveric dissections were performed on 11 temporal bones, approaching the internal auditory meatus directly through the external ear canal and avoiding mastoidectomy. In all cases, it was possible to dissect the internal carotid artery and jugular bulb with a 0° endoscope, and with good control of these two structures. The medial wall of the bony labyrinth guaranteed good landmarks for IAC dissection, such as the spherical recess, and the labyrinthine tract of the facial nerve. The IAC can be thoroughly visualized in the cadaver using EETA, avoiding mastoidectomy, extensive temporal bone tissue removal and external incisions. Clinically based reports will be required in future to strengthen our preliminary results.

The retro- and hypotympanum are hidden areas of the middle ear, only poorly recognized. Nevertheless, this region is of relevant clinical significance, since it is regularly affected by disease such as cholesteatoma. The aim of this study is to explore and describe the anatomical variants of the hypo- and retrotympanum by the means of transcanal endoscopy. We hypothesize a significant variability of this hidden region of the middle ear. Moreover, we believe that the minimal invasive, endoscopic access is suitable since angled scopes may be used to explore the region. To this end a total of 125 middle ears (83 cadaveric dissections, 42 surgical cases) were explored by the means of 3 mm straight and angled scopes. The variants were documented photographically and tabularized. The bony crests ponticulus, subiculum and finiculus were most frequently represented as ridges. The ponticulus showed the highest variability with 38% ridge, 35% bridge and 27% incomplete presentation. The subiculum was bridge-shaped only in 8% of the cases, the finiculus in 17%. The sinus tympani had a normal configuration in 66%. A subcochlear canaliculus was detectable in 50%. The retro- and hypotympanum were classified, respectively, to the present bony crests and sinus in a novel classification type I-IV. In conclusion, we found abundant variability of the bony structures in the retro- and hypotympanum. The endoscopic access is suitable and offers thorough understanding and panoramic views of these hidden areas.

2C.

Objective Transcanal exclusive endoscopic ear surgery requires the management of the endoscope and the surgical instruments in the external auditory canal. Bleeding in this narrow space is one of the most challenging issues, especially for novice endoscopic ear surgeons. We aim to assess the severity and occurrence of bleeding and describe strategies to control the bleeding during endoscopic ear surgery. We hypothesize that bleeding is reasonably controllable in endoscopic ear surgery. Study Design Case series with chart review. Setting Tertiary referral center. Subjects and Methods We retrospectively assessed 104 consecutive cases of exclusive endoscopic ear surgery at the University Hospital of Modena, Italy. The surgical videos and the patient charts were carefully investigated and analyzed. Results Hemostatic agents included injection of diluted epinephrine (1:200,000, 2% mepivacaine), cottonoids soaked with epinephrine (1:1000), mono- or bipolar cautery, washing with hydrogen peroxide, and self-suctioning instruments. The localization of bleeding in the external auditory canal was most frequently the posterior superior part, and inside of the middle ear, it was the pathology itself. Statistical analysis revealed significant differences comparing the mean arterial pressure and the type of intervention among bleeding scores. Conclusion The management of bleeding in endoscopic ear surgery is feasible through widely available hemostatic agents in reasonable frequency. This study gives an instructive overview on how to manage the bleeding in the exclusive endoscopic technique. Even the highest bleeding scores could be managed in an exclusively endoscopic technique.