後天性真珠腫に対する外耳道後壁保存型鼓室形成術

抄録

In the canal wall up technique (CWUT) for removal of cholesteatoma, keeping the consistency of the cholesteatoma matrix is very important. To keep the consistency of the matrix, we begin by pushing the bottom of the cholesteatoma from the mastoid antrum towards the external auditory canal. After detaching the matrix from the underlying mucosa or bone, we finally cut the epithelium at the point of its entrance from the external auditory canal into the middle ear. This method combined with scutumplasty and cartilage tympanoplasty can also prevent deformity of the external auditory canal and reduce the risk of recurrent cholesteatoma, by minimizing lateral tympanoplasty.

In this study, we classified a total 42 patients with pars flaccida cholesteatoma and 37 patients with pars tensa cholesteatoma who underwent primary surgery at Teikyo University School of Medicine, Mizonokuchi Hospital, between January 2015 and July 2019, according to the Classification and Staging of Cholesteatoma proposed by the Japanese Otological Society in 2015.

Among the 42 ears with pars flaccida cholesteatoma, 14 (33.3%) were classified as showed stage I, 20 (47.7%) as stage II, and 8 (19%) as stage III, with no case (0%) of stage IV. Among the 37 ears with pars tensa cholesteatoma, 4 (10.8%) were classified as stage I, 23 (62.2%) as stage II, and 10 (27%) as stage III, with no case (0%) of stage IV. The successful outcome rate was 100% in the stage I cases, 85% in the stage II cases, and 75% in the stage III cases of the pars flaccida cholesteatoma group, and 100% in the stage I cases, 69.6% in the stage II cases, and 50% in the stage III cases of the pars tensa cholesteatoma group. The residual and recurrent disease rate was 0% in the pars flaccida cholesteatoma group, and 2.7% in the pars tensa cholesteatoma group.

We consider that our method of pushing the bottom of cholesteatoma from the mastoid antrum towards the external auditory canal is quite efficient for keeping the consistency of the matrix and minimizing lateral tympanoplasty to reduce the risk of recurrent of cholesteatoma.