Canalplasty Periprocedural Care

Some surgeons may recommend their patients undergo treatment of external otitis media prior to surgery with topical antimicrobial drops that may include a steroid solution. Occasionally oral antimicrobial are required for severe infections.

Equipment

An otologic drill with tools including cutting and diamond burrs are required for many cases, as well as an operating microscope for improved visualization. A facial nerve monitoring unit may be desired if the surgeon feels the facial nerve may be at risk during the surgery.

Patient preparation

A single dose of antibiotics protective against skin flora is to be administered intravenously prior to skin incision.

Anesthesia

Canalplasty procedures are performed under general anesthesia. In cases in which facial nerve monitoring is required, long-acting paralytics are not recommended.

Local anesthesia is often also administered in the area around the planned incision, in the postauricular sulcus and in the external auditory canal. If feasible, injection of local anesthesia is performed in the cartilaginous, hair-bearing portion of the external auditory canal (EAC). Lidocaine mixed with diluted epinephrine (1:100,000) is typically used in order to decrease bleeding from the initial incisions

Positioning

After intubation, the patient is positioned supine on the operating room table with the head turned away from the surgeon. Typically, the bed is turned 180° away from the anesthesiology team to allow better maneuvering of the operating microscope.

Canalplasty is typically performed as an outpatient procedure. Patients are observed in the postanesthesia care unit until recovered from anesthesia before being discharged to home. To prevent re-stenosis, a stent may be fashioned and placed in the external auditory canal. Iodoform gauze may be used, with a cotton pack overlying the gauze that is replaced regularly by the patient at home.

Having the ear canal remain dry in the short-term postoperative period is usually advised; this allows healing and to prevent infection. Some surgeons suggest that patients may return to water exposure as early as one week postoperatively if wearing a silicone ear plug. ^[4] Antibiotic drops may be prescribed. Aside from local pain from surgery, discomfort during eating is common for up to 2 weeks postoperatively. A change in the shape of the ear after surgery may occur; however, this is usually due to swelling from the procedure and should resolve as swelling subsides.

Packing will be removed from the canal in approximately 2–3 weeks. Any nondissolving sutures will be removed in 7–10 days. Patients with canalplasty require frequent visits in the early postoperative period to ensure adequate healing of the wound. Long-term, EAC stenosis may recur in up to 10% of cases. If a skin graft was required during surgery, patients may require regular visits for debridement of the ear canal due to interruption of the natural epithelial migration of EAC skin.

Delayed healing

Postauricular approach is associated with prolonged healing in less than 5% of cases, tympanic membrane perforation in 0.2%, and a mild decrease in hearing at one frequency in less than 5% of patients. ^[9] The condition may recur in up to 10% of cases. Healing time of the canalplasty incisions can range from 6 weeks to 6 months. In a review of 100 cases, 90% of canalplasty incisions had healed by 2 months postsurgery. ^[4]

Facial nerve injury

The facial nerve is theoretically at risk during surgery at its tympanic segment. Injury to this nerve is one of the most feared complications of any otologic surgery. Approximately 25–30% of facial nerves have an aberrant course that can put the nerve at risk; however, risk to facial nerve injury in this procedure is low. A mild, transient facial weakness was noted in 2% of patients in one series. ^[4] This weakness resolved in both cases spontaneously.

Hearing loss

A tympanic membrane perforation can cause a conductive hearing loss. One series discovered an approximately 5% chance of greater than 15 dB hearing loss at 4000 Hz after canalplasty; however, the risk of a 15 dB change in pure tone average was less than 1%.

Change in taste

The nerve controlling taste to the side of the tongue on the side of surgery could be injured during the procedure.

Infection

Infection of the wound may occur and can manifest with erythema (redness of the skin), pain, or swelling in the area around the sutures. An oral antibiotic that covers skin flora may be required. Postoperative infection can also prolong the healing period.

Ear canal scarring

The rate of re-stenosis was reported as 4% and was primarily associated with use of a middle temporal flap to cover a bony defect. ^[9] Close postoperative monitoring is required to identify re-stenosis early.