Ossicular reconstruction: Incus versus universal titanium prosthesis

Objectives

The main purpose of this study is to compare audiological outcomes of incus reconstruction, Xomed Medtronic universal titanium partial ossicular replacement prosthesis (PORP) and total ossicular replacement prosthesis (TORP). We also compared results based on surgical technique, history of previous surgery, form of the prosthesis head, pathology and frequency.

Methods

A chart review was performed and included reconstructions performed between June 2003 and December 2006. Results were based on air–bone gap and pure tone average.

Results

Postoperative mean air–bone gap and mean pure tone average are significantly lower using incus reconstruction compared with the titanium prosthesis groups. PORP and TORP groups yielded similar outcomes. Closure of ABG is similar in all three groups. Postoperative results were better using an intact canal wall mastoidectomy compared with a canal wall down technique, but ABG closure was similar in both groups. Primary surgeries gave better results than revisions of reconstructions performed by the senior author or elsewhere.

Conclusion

Though Xomed Medtronic titanium prostheses are effective in ossicular reconstruction, incus reconstruction is at least as effective when feasible. Canal wall down mastoidectomy should be reserved for cases where preservation of the canal wall is contraindicated. Previous same ear surgery is a poor prognostic factor for successful outcome. Preliminary results indicate that round head PORPs may be superior to their oval head counterparts.     

Incus and Stapes Footplate Simulator

Prosthesis placement in stapes surgery is difficult to master. Although temporal bone dissection is an important adjunct to operative experience and anatomic knowledge when training residents to perform this procedure, the high cost and scarcity of temporal bones available for teaching purposes limit their convenience as teaching tools. Therefore, to augment training of residents, the authors developed an inexpensive, easily constructed middle ear simulator made from a disposable drinking cup, toothpicks, and a tongue depressor. The device is used with a microscope and ear instruments to manipulate, place, and crimp stapes prostheses. Improved surgical skills can lead to better surgical results, and this middle ear simulator can help to improve otologic surgical skills by giving residents the opportunity to practice techniques necessary to master stapes surgery.     

Stapedectomy: Incus bypass procedures. A report of 203 operations

The records of 203 stapedectomy operations in which we used a prosthesis from the malleus handle or a columella from the tympanic membrane were reviewed; 63 operations were primary stapedectomies, and 85% had a postoperative conductive deficit of 15 dB or less. The most common single indication for an incus bypass procedure was idiopathic malleus head fixation. Sixty-six operations were revision stapedectomies; 65% had a postoperative deficit of 15 dB or less. In 50% the bypass indication was necrosis of the incus. There were 74 stapedectomies in a previously fenestrated ear; 60% had a postoperative deficit of 15 dB or less. Incus bypass procedures in stapedectomy, when indicated, yield satisfactory hearing results. Otolaryngologists who perform stapedectomy must be familiar with these procedures.     

Congenital Absence of the Long Process of the Incus

Objective/Hypothesis: To review the case reports of three generations of one family, suffering from bilateral conductive hearing loss due to congenital absence of the long process of the incus. Study Design: Review of the literature regarding hereditary congenital absence of the long process of the incus to determine its mode of inheritance such as autosomal dominant or X-linked. Also document the types and results of surgical repairs performed by previous investigators of this defect and compare them with the present study. Methods: Three female patients of direct lineage. Mother, daughter, and granddaughter, who were personally seen, operated on, and followed up over a period of 26 years. Results: All three female patients presented with similar symptoms and findings of hearing impairment since birth, with no history of ear infections, and with normal appearing tympanic membranes. However, they had severe conductive hearing loss with normal bone conduction and discrimination. Operative findings were identical in all three patients, with the incus ending in a blind stub, and with absence of the capitulum of the stapes. The type of ossicular reconstruction varied with the changing of times and advances in otologic surgery, as well as the prosthetic materials used. All three patients received improvement in their hearing, and this improvement has been maintained over the 26-year span of the study. Conclusions: Hearing loss due to congenital absence of the incus is uncommon but not rare. Interestingly, no other instance of inherited cases were reported in the literature. In this family the defect appears to be an inherited trait either due to an autosomal dominant mutation or an X-linked dominant inheritance. This abnormality is amendable to surgery, and any well-executed technique usually gives good hearing results.