This video illustrates an endoscopic ossiculoplasty using a total ossicular replacement prosthesis (TORP) in a patient with a mixed hearing loss and a large conductive component. The video highlights the middle ear anatomy including a dehiscent and prolapsed facial nerve partially obstructing the oval window. Technical pearls for the ossiculoplasty are also highlighted.
Cameron C. Wick, MD
Department of Otolaryngology – Head and Neck Surgery, Washington University School of Medicine, St. Louis, MO, USA
J. Walter Kutz Jr., MD
Department of Otolaryngology – Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
Procedure: Endoscopic ossiculoplasty (total ossicular replacement prosthesis - TORP) with a prolapsed facial nerve.
Introduction: Endoscopic ossiculoplasties, particularly TORP, are challenging secondary to the surgeon having only one-hand to manipulate the prosthesis.
Indications/Contraindications: TORP is indicated for conductive hearing loss with no useful stapes superstructure. Contraindications include stapes footplate fixation or persistent disease in the middle ear cleft.
Materials and Methods: This is a single case report using intraoperative video to highlight middle ear anatomy and technical pearls of endoscopic ossiculoplasty.
Result: 3-month postoperative audiogram shows correction of the conductive component of the patient's hearing loss. Technical pearls include use of gel foam and capillary action to assist with prosthesis placement and stability.
Conclusion: Endoscopic ossiculoplasty, even TORP, is feasible.
Transcanal endoscopic ear surgery (TEES) is gaining popularity for its improved visualization of the middle ear space and wide-angle view. Chronic ear disease, including tympanic membrane perforations and cholesteatoma, are frequently being addressed in an exclusively endoscopic fashion. Chronic ear disease often alters the ossicular chain making an ossiculoplasty necessary. This delicate surgical procedure has additional challenges when attempted using the one-handed endoscopic technique. The accompanying video shows an illustrative case where the endoscope was useful to visualize unusual middle ear anatomy and it highlights some of the technical pearls for successful total ossicular replacement prosthesis (TORP) placement.
The standard TEES setup was utilized. This entails supine position, head rotated slightly with the operative ear up, and the head of bed slightly elevated. Facial nerve monitoring was setup and is routinely used for chronic ear surgery, particularly revision cases. After prepping the ear with betadine paint, an otologic drape containing a pouch was used. Standard middle ear instrumentation can be used or specially designed endoscopic ear trays are available. In this video, standard ear instrumentation are used as well as a disposable 7200 Beaver blade. The endoscope is a 3-mm diameter, 14-cm length zero-degree scope from Storz. The prosthesis is a titanium offset ALTO TORP from Grace Medical.
Preoperative work-up included a detailed microscopic ear exam, tuning fork exam, and audiogram. Radiographic studies were not obtained.
The previously placed TORP had fallen over and was no longer in the oval window niche. The old prosthesis was removed. The facial nerve was noted to be dehiscent and prolapsed over a portion of the oval window. Careful lysis of adhesions allowed a small area of the stapes footplate to be visualized. Because this area was small, a footplate shoe was not used for this ossiculoplasty.
The ossiculoplasty size is first measured with a plastic sizing prosthesis. Once the correct size is established the titanium offset ALTO TORP is cut to size on the back table. Prior to placement, the oval window niche is prepared by placing gel foam around the anticipated landing area. The gel foam helps the endoscopic surgeon so that the prosthesis does not fall over, but rather can be supported by the gel foam. Additionally, capillary action from the undersurface of the tympanic membrane helps support the prosthesis.
Three-months after successful placement the patient's air-bone gap had been dramatically reduced, essentially eliminating the conductive component of his hearing loss. His speech discrimination score also increased.
Endoscopes are now being used to manage a myriad of otologic conditions, including cholesteatoma, tympanic membrane perforation, otosclerosis, and skull base pathology. The challenge of endoscopic ossiculoplasty is the one-handed prosthesis placement, particularly for a TORP which is top-heavy with a narrow base. A recent comparison of endoscopic versus microscopic ossiculoplasty results showed no difference in the audiologic outcomes (1). Therefore, with some technical modifications endoscopic ossiculoplasty, including TORP, is feasible.
1. Yawn RJ, Hunter JB, O'Connell BP, Wanna GB, Killeen DE, Wick CC, Isaacson B, Rivas A. Audiometric outcomes following endoscopic ossicular chain reconstruction. Otol Neurotol. 2017;38(9):1296-1300.