[Skull base defects in the middle and posterior cranial fossa with unchanged mucous lining middle ear spaces]

Skull bone defects in the region of middle ear are usually observed in the cases of chronic otitis media. Such loses can also be congenital, posttraumatic, iatrogenic or due to hyperplasia. They can potentially lead to development of otogenic intracranial complications.

We present the patients who were not observed during otosurgery to have any pathological changes to the mucous of the middle ear and were diagnosed as having bone defects in the middle and/or posterior cranial fossa. We discuss also methods of reconstruction during otosurgery.

The prospective analysis involves the patients operated on middle ear in the Department of Otolaryngology at the Jagiellonian University of Krakow in the years 2007-2011. 495 first-time otosurgeries were performed in this period of time.

Skull bone defects were diagnosed in 46 patients who had undergone surgery and 25% of these patients had no changes to the middle ear mucous. This points to congenital etiology of the defects. In this group the most common cause for otosurgery was chronic otitis media (10 patients). In 1 patient, bone defect occurred along with otosclerosis. In patients with congenital skull bone defects otogenic intracranial complications were described in 4 cases.

Nearly 80% of skull bone defects remain asymptomatic; they are revealed incidentally during the surgery of the middle ear. The above observations emphasize the significant role of preoperative imaging diagnostics. The methods of bone defects reconstruction using the fascia, strengthened with the pedicle muscle flap where larger defects occurred, as well as with either bone lamella or cartilage in particular cases, proved successful.