Step-By-Step Stapedotomy through Transcanal Exclusive Endoscopic Approach. We are going to show a case of endoscopic stape surgery from operating room setting and patient positioning to postoperative care. I'm going to guide you through a step-by-step description of the surgical procedure with technical hints to allow any surgeon to perform stape surgery with a total endoscopic approach.
A growing number of papers have shown that endoscopic stape surgery is safe, feasible, and has favorable outcomes similar to traditional stapedotomy. However, endoscopic stape surgery could be challenging for surgeons who do not have much experience with the use of the endoscope. The problem of sharing the surgical field between the endoscope and the operating instrument could be easily overcome if proper instruments ending is understood.
One handed billion control could be sometimes frustrating for the novice surgeon. Moreover, it is important to properly position the patient and set up the operating room to guarantee a comfortable position for the surgeon across the entire procedure. We report a case of a 56-year-old female who came to our attention reporting slowly and progressive bilateral hearing loss without vertigo or tinnitus.
While the right otoscopy was normal the audiometric test demonstrated a right moderate mixed hearing loss. The tympanogram was type A bilaterally and stapedial reflexes were absent, suggesting bilateral to sclerosis. No CT scan was deemed necessary as preparative assessment.
After oro-tracheal intubation and general anesthesia position the patients supine with the head tilted towards the opposite side of the affected ear with the chin slightly hyper extended. Pull down the same-side shoulder as much as possible to create a wide angle between the head and the shoulder allowing easier access to the ear. Perform preliminary anesthesia injecting around 1-2 milliliters of local anesthetic diluted with a vasoconstrictor agent in four main points of the external auditory canal skin:posterior wall, superior and inferior angle and retrotragal region.
Use an iodopovidone-soaked gauze goes to sterilize the whole external ear to create an aseptic field. Assure that iodopovidone enters the external auditory canal and reaches the tympanic membrane. The high resolution monitor is placed in front of the surgeon at his eyes level at adequate distance to keep a comfortable position of the head and neck during the surgery.
Connect the 3 millimeter diameter, 15 centimeter length, zero degree endoscope to the high-definition digital camera and xenon light source. Keep the light source at 50%intensity to prevent heat damage to the inner ear. After doing white balance and adjusting focus prepare a quality de-misting solution to clean the endoscope tip.
Under direct endoscopic vision, perform intraoperative anesthesia in the superior cell plane of the posterior wall of the canal. After cutting hairs of the most lateral part of the external auditory canal use the monopolar to delineate the tympano-meatal flap incision from 5 to 12 o'clock about 8 to 10 millimeter far from the annulus. Used the round knife to perform the actual skin incision following the previously marked line and raise the tympano-meatal flap with the help of epinephrine-soaked cottonoids.
Once the annulus is identified as a white thickening of the tympanic membrane continue the dissection under it. Detach the pars flaccida from the short process of the malleus with Hartmann forceps, keeping the pars tensa adherent to the umbus. During this step, identify the chorda tympani as a whitish string emerging from the cordal eminence and leave it untouched.
To achieve a good exposure of the oval window region, variable removal of the scutum and the posterior bony part of the external auditory canal should be performed through the curette. In some cases, even if the oval window region is fully exposed, some curettage is necessary to create a favorable working area on the stapes. To further expose the footplate, the nerve is usually displaced majorly with a hook.
After confirming stapes fixation, use the micro drill with a 0.6 millimeter diamond burr to perform a posterior crurotomy. Then use the same burr to perform a hole in the middle posterior portion of the footplate. Cut to the stapedial tendon with Bellucci scissors.
Now disarticulate the incus from the stapes with the help of a hook, and remove the stapes superstructure. Use the Fisch hook to regularize the footplate hole and check its adequate caliber, as well as to remove possible small bone fragments from the vestibule. Now it's time to insert the stapes prosthesis into the external auditory canal using the suction tube.
Here, we are using a 0.6 per 4.75 millimeter prothesis. Gently position it into the stapedotomy hole with the help of a hook. Crimp the prosthesis hook after anchoring it to the long process of the incus.
Gently pushing on the handle of the malleus check the proper movement of the prothesis. Replace the tympano-meatal flap and pack external auditor canal with resorbable hemostatic pledgets. Cover the auricle with an adhesive plaster no compression is needed.
Allow the patient to drink, eat and stand up at least 8 hours post-operatively if no nausea or vomiting occurred. The following day assess the facial nerve function using the House-Brackman scale and the presence of spontaneous nystagmus with Frenzel goggles. Perform bone conduction pure tonal audiometry to exclude sensorineural hearing loss.
The patient had a normal post-operative course without facial palsy or vertigo. The 6-month post-operative hearing test revealed a complete closure of the air-bone gap. The otoendoscopy showed regular healing of the tympanic membrane and the patient denied any taste impairment.
This protocol could guide any otologic surgeon across endoscopic stape surgery. We suggest some training with basic procedures such as endoscopic myringotomy and myringoplasty before performing the endoscopic stapedotomy. Thank you for your attention.
