Grading system for the selection of patients with congenital aural atresia.

It is generally recognized that surgery for congenital aural atresia is difficult. In an effort to select those patients who have the greatest chance of success, we have developed a grading scheme based on the preoperative temporal bone CT scan and the appearance of the external ear. Patients are graded on a possible best score of 10. The stapes is assigned the highest rating (2 points), while all other entrees on the scale are 1 point. The grade assigned preoperatively has been shown to correlate well with the patient's chance of success, herein defined as a postoperative speech reception threshold of 15 to 25 dB. A patient with a preoperative grade of 8/10 would, therefore, have a 80 percent chance of achieving this threshold. Patients with scores of 5/10, or less, are not considered surgical candidates, because the risk of the operation would outweigh the potential benefits. We have found that the grading system allows us to avoid impossible surgical cases while allowing for a reasonable prediction of the hearing outcome.