Uncorrectable Dimensions in Congenital Canal Atresia Making Us to Revise Operative Candidacy and Patient Selection
Wael A Alzamil
Journal Title:Acta Scientific Otolaryngology
Background: Congenital aural atresia is common birth defects and is often associated with au ricular and middle ear deformities.
The external auditory canal anomaly varies from slightly narrow to complete atresia. Congenital external auditory canal steno sis is
defined by Jahrsdoerfer., et al. as an EAC with a diameter of less than 4 mm . The surgical management for canal atresia and steno-
sis is aimed to improve hearing and establish an appropriate auditory canal status for possible application of hearing aids. In clinical
practice, we found that patients with canal stenosis and partial atresia have a better postoperative hearing improvement and few er
postoperative complications than those with complete canal atresia . By analyzing the temporal CT images and intraoperative
findings in patients with canal atresia and comparing those with images and intraoperative findings from normal canals, we further
understand ex ternal and middle ear development to improve surgical candida cy selection and avoid unnecessary complications .
In addition to the status of the ossicu lar chain, the degree of development and pneumatization of the tympanic cavity and mastoid,
and the course of the facial nerve, the most important information taken from CT and intraoperative findings are the dimensions of
the proposed future canal. There are main three dimensions which are the lateral and medial canal diameters and the depth of the
canal. Each diameter has two main diagonals, the antero posterior dimension and the supero inferior dimension. This study will focus
on the dimensions of the created canal or cavity and whether it is correctable or uncorrectable.
Aim of the Study: To match the C.T. scan and intraoperative findings with the surgical outcome for patients with congenital canal
atresia and illustrate the operated uncorrectable dimensions with unfavorable outcome for later proper patient selection and surgi-
cal candidacy considerations.
Patients and Methods: A prospective, study conducted from September 2017 to December 2020 on 50 patients suffering congenital
canal atresia. Patients have been subjected to preoperative audiological assessment and high resolution C.T. scanning. All patients ad-
dressing the study have been scored according to the Jahrsdoerfer Grading Scale selecting patients with scores above 6 (50 patients).
All patients have undergone surgical meatocanaloplasty via anterior approach or posterior approach according to the C.T. findings.
Intraoperative data collection was done to be matched with preoperative C.T. data and correlated later on with the final outcome.
Postoperative regular follow up visits were done obligatory every two to three weeks for at least six months and for regular packing.
Results: Data collection was done involving intraoperative anatomical findings, difficulties or complications, immediate and late
postoperative results including the final outcome. Intraoperative measurements have showed marked reduction of the depth of the
cavity or the created canal ranging from 1 to 1.5 cm in 47 operated ears having complete atresia and more favorable depth ranging
from 1.75 to 2.25 cm in the last three patients with C.T. evidence of partial atresia and less affected tympanic ring. Regarding the
antero-posterior distance of the cavity, it was doubled and tripled after radical mastoidectomy in the 47 patients of complete atresia