Chronic mucosal disease, as opposed to cholesteatoma, is more directly related to failure of the ventilation system involving three channels. Isthmus anticus and isthmus posticus are channels in front and behind the long process of the incus and there is an anterior most ventilation pathway through the tensor fold. The epitympanic space also contributes to ventilation. The authors believe that conventional cortical mastoidectomy, even with attic extension, fails to address blockage of these channels which are obstructed by hypertrophied mucosa. The study comprised 36 patients in each group. One underwent cortical mastoidectomy and the other had an endoscopic approach. In the latter group of patients, the hypertrophied mucosa was removed precisely where it blocked these channels. A 12-month follow-up showed better results in the endoscopic group in terms of postoperative air-bone gap, postoperative pain, graft uptake vertigo and long-term complications. The surgical time was much less. This approach appears useful and is perhaps safer than a combined approach tympanoplasty, sometimes used to achieve the same goal.