Building bridges in the ear: hearing bone chain reconstruction

  “I can finally hear people’s speech clearly, and I can swim and bathe with confidence.” Three months ago, Xiao Xin underwent surgery for chronic suppurative otitis media in his right ear. After the surgery, his ear no longer flows and, more importantly, he gained a level of hearing that he could only dream of. Tympanoplasty has given many patients with chronic suppurative otitis media a “new lease of life” on their hearing, and is referred to by patients as a “bypass” in the ear.  Two years ago, Xiao Xin found that his right ear was painful and repeatedly “flowing”, sometimes with yellowish pus, emitting a foul odor, which made even bathing a frightening experience. The hearing in his right ear was also getting worse and worse, always like a cotton ball blocked. The doctor’s diagnosis was “chronic suppurative otitis media”, and Xiao Xin was very hesitant about the surgery: “If the inflamed part is cleared after the surgery, will the hearing be worse or lost?” This is a common psychological reaction of patients with chronic suppurative otitis media before considering whether to undergo surgery. The doctor told Xiao Xin, “The reason why human beings can hear sound is that the outer and middle ears need to conduct sound to the inner ear, and the auditory receptor cells in the inner ear feel the sound and transmit it to the brain to produce auditory sensation. Chronic suppurative otitis media affects sound conduction and leads to conductive deafness. The key part of sound conduction is the tympanic membrane and the auditory chain, which consists of three very small auditory bones. In patients with chronic suppurative otitis media, due to the long-term corrosion of the middle ear, the tympanic membrane and part of the auditory tuberosity are missing, so the ability to conduct sound is reduced, resulting in hearing loss and even deafness. The purpose of the surgery is to thoroughly clean the lesion and repair the eardrum to eliminate pus flow and obtain a dry ear. In most cases, artificial auditory tuberosities will be implanted at the same time or in stages to re-establish a new sound conduction ‘bridge’, which can be a multi-benefit.”  After the surgery to remove the lesion and reconstruct the auditory chain, as well as regular post-operative dressing changes, Xiao Xin’s wound gradually healed and her hearing improved day by day, and finally, after a routine post-operative examination, the doctor told her that her hearing had improved by 30 decibels, which was close to normal hearing levels, and would continue to improve.  Since the reconstruction of the auditory chain was introduced in the 1950s, otologists at home and abroad have carried out a lot of practice and exploration. As patients’ postoperative hearing requirements have increased, the classical mastoid radical surgery has been gradually replaced by various types of tympanoplasty with or without auditory chain reconstruction. There is a consensus to preserve, restore and improve hearing based on complete excision of the lesion. The optimal timing of auditory chain reconstruction is determined by the extent and degree of the lesion, and an artificial auditory bone of appropriate shape and material is selected. If the lesion is extensive and severe, and the ventilation of the middle ear is poor, the artificial hearing bone should be implanted about six months after the lesion is cleared to avoid postoperative adhesions or artificial hearing bone prolapse. There are three types of artificial bone in common use: partial hearing bone prosthesis, full hearing bone prosthesis, and hearing bone prosthesis connecting the hammer bone to the stapes.