THE chronic draining ear is usually associated with underlying mastoid disease which must be removed before the surgeon can perform a combined mastoidectomy and tympanoplasty. For the removal of mastoid disease, in addition to the simple modified radical and radical mastoidectomies, the otologic surgeon now has the combined posterior-anterior mastoidectomy and tympanoplasty with the preservation of the intervening bony canal wall. This preservation of the canal wall is designed to eliminate the external nuisance factors of an open mastoid cavity and give the patient a near-normal trouble-free ear.
The preservation of the posterior bony wall of the external auditory canal, intervening between the middle ear cavity and the mastoid cavity, has in specific anatomic and pathologic circumstances created a more nearly normal postoperative ear, trouble-free from external sources. In other pathologic and anatomic circumstances the preservation of the canal wall creates a problem ear from internal sources. These internal problems