Objective: The aim of this study is to describe the endoscopic anatomy of the subtympanic sinus (STS), establish a classification according to its extension regarding the level of the facial nerve (FN), and assess the feasibility of the transcanal endoscopic approach to the STS. Study Design: Experimental anatomic research. Setting: Temporal bone laboratory. Methods: We performed endoscopic dissection of 34 human whole head and ear block specimens. Of those, 29 underwent high-resolution computed tomography. The STS was classified according to its extension regarding the level of the FN: type A, no extension medial to the FN; type B, extension to the medial limit of the FN; type C, extension of the sinus medially and posteriorly from the FN into the mastoid cavity. Results: The majority of cases (n = 21, 72%) showed a shallow type A STS. We observed a deep type B configuration in 6 cases (21%) and a type C in 2 cases (7%). The STS was completely exposable with a 0° endoscope in 44% of the specimens. Using a 45° endoscope, we gained complete insight in 79%. However, in 21% of the cases, the posteromedial extension of the STS was too deep to be completely explored by an endoscopic transcanal approach. Conclusion: The majority of the STS is shallow and does not extend medially from the FN. This morphologic variant allows complete transcanal endoscopic visualization. In more excavated STS, a complete endoscopic exploration is not achievable, and a retrofacial approach may be adopted to completely access the STS.
Novel Surgical and Radiologic Classification of the Subtympanic Sinus: Implications for Endoscopic Ear Surgery / Anschuetz L.; Alicandri-Ciufelli M.; Bonali M.; Fermi M.; Caversaccio M.; Presutti L.; Marchioni D.. - In: OTOLARYNGOLOGY-HEAD AND NECK SURGERY. - ISSN 0194-5998. - ELETTRONICO. - 159:6(2018), pp. 1037-1042. [10.1177/0194599818787180]
Novel Surgical and Radiologic Classification of the Subtympanic Sinus: Implications for Endoscopic Ear Surgery
Fermi M.;Presutti L.;
2018
Abstract
Objective: The aim of this study is to describe the endoscopic anatomy of the subtympanic sinus (STS), establish a classification according to its extension regarding the level of the facial nerve (FN), and assess the feasibility of the transcanal endoscopic approach to the STS. Study Design: Experimental anatomic research. Setting: Temporal bone laboratory. Methods: We performed endoscopic dissection of 34 human whole head and ear block specimens. Of those, 29 underwent high-resolution computed tomography. The STS was classified according to its extension regarding the level of the FN: type A, no extension medial to the FN; type B, extension to the medial limit of the FN; type C, extension of the sinus medially and posteriorly from the FN into the mastoid cavity. Results: The majority of cases (n = 21, 72%) showed a shallow type A STS. We observed a deep type B configuration in 6 cases (21%) and a type C in 2 cases (7%). The STS was completely exposable with a 0° endoscope in 44% of the specimens. Using a 45° endoscope, we gained complete insight in 79%. However, in 21% of the cases, the posteromedial extension of the STS was too deep to be completely explored by an endoscopic transcanal approach. Conclusion: The majority of the STS is shallow and does not extend medially from the FN. This morphologic variant allows complete transcanal endoscopic visualization. In more excavated STS, a complete endoscopic exploration is not achievable, and a retrofacial approach may be adopted to completely access the STS.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.