When the malleus handle is present, the modification of the palisade technique, as described above, is utilized. An acoustic benefit has been shown with the incorporation of the malleus in ossicular reconstruction, possibly due to the cantenary action of the malleus in the TM.32 Likewise, the presence of the malleus with an intact anterior malleolar ligament offers improved prosthesis stability by allowing precise length adjustments and ultimate fit, leading to optimal hearing results.45 This has led us to abandon the use of the tragal island flap when the malleus is needed for ossicular reconstruction due to the fact that prior placement of the flap, using the underlay technique as described, obscures the malleus and makes the subsequent ossicular reconstruction less precise. Likewise, it is frequently difficult to carve the cartilage with enough precision so that the island flap fits exactly against the canal wall, which is necessary in cases involving cholesteatoma. We have seen cholesteatomas recur when even a small gap is left between the posterior cartilage and the canal wall. Thus, the palisade technique is preferred in this situation.
When the malleus handle and suspensory ligaments are present, a partial ossicular replacement prosthesis (PORP) cut to 2 mm and a total ossicular replacement prosthesis (TORP) cut to 4.0 to 4.5 mm can be consistently used for precise reconstruction when the notch of the prosthesis is placed just inferior to the insertion of the tensor tympani (Fig. 6-10). After precise ossicular reconstruction is performed, the posterior half of the TM is reconstructed with cartilage pieces, as described above for the palisade technique. The TM is pieced together like a jigsaw puzzle: the half-moon-shaped piece is placed on top of the prosthesis first, abutting the malleus handle, followed by the scutum piece. Because the usual indication for this technique is cholesteatoma, any spaces left between these two plates and the canal wall are reconstructed with slivers of cartilage cut to fit precisely in these areas. The reconstruction is then covered with perichondrium if available; however, this is not necessary in most cases if good fit is achieved. No space is left between the canal wall and reconstructed TM to prevent cholesteatoma or retraction pocket recurrence. In addition, the
anterior half of the TM is typically not reconstructed with cartilage so as to allow postoperative surveillance and tube insertion, if necessary.
If reconstruction of the anterior TM is necessary due to pathology, perichondrium is used. The technique is the same, but after precise fitting of the prosthesis to the malleus handle, the prosthesis is removed and the perichondrium is placed as an underlay graft. The prosthesis is then reinserted, with palpation of the malleus handle through the graft to facilitate precise fit. The posterior palisade technique is then performed.
Was this article helpful?
Have you recently experienced hearing loss? Most probably you need hearing aids, but don't know much about them. To learn everything you need to know about hearing aids, read the eBook, Hearing Aids Inside Out. The book comprises 113 pages of excellent content utterly free of technical jargon, written in simple language, and in a flowing style that can easily be read and understood by all.