Indications
Tympanic membrane (TM) perforation is a common otologic condition with a prevalence of 2.1% in US adults >12, corresponding to 5.8 million Americans. Perforations are most often caused by infection or trauma. Pediatric populations are more likely to experience perforation due to infection, while older adults are more likely to experience perforation due to trauma. TM perforations result in otalgia, otorrhea, increased risk of infection, and hearing loss. The severity of conductive hearing loss is associated with the size of the perforation, ranging from 10 to 40 dB, and primarily affects low and mid frequencies, due to the decrease in sound pressure difference across the perforated eardrum. , The majority of TM perforations will heal spontaneously within weeks of the initial insult. Advanced patient age and increased size of the perforation are associated with slower healing time. The primary causes of nonclosure are secondary infection and the size of the perforation.
For those perforations that do not close spontaneously, surgical repair is considered. Surgical repair typically requires either myringoplasty or tympanoplasty. The underlay technique is the gold-standard tympanoplasty repair, in which the graft is placed medial to the TM either via a transcanal approach or a postauricular incision. Additional methods include the lateral graft technique, also called the overlay, in which the graft is placed lateral to the TM.
Traditional tympanoplasty techniques are performed in an operating room (OR) under general anesthesia. Recently, advancements in surgical techniques and improved access to endoscopic equipment have allowed for the development of TM repair methods in awake patients. This repair occurs in the office and does not require general anesthesia for patients.
In-office repair is indicated for chronic nonhealing TM perforations and can be considered in place of traditional tympanoplasty depending on the features of the perforation, patient, and physician-specific factors. In-office repair can be performed for perforations in any quadrant and is best suited to small perforations ( Fig. 53.1 ) comprising less than 25% of the total surface area of the TM. However, larger perforations can also be repaired with this technique if patients are highly motivated to avoid the operating theatre. Marginal and subtotal perforations are relative contraindications to in-office repair. This technique can be used in patients who cannot tolerate or do not wish to undergo general anesthesia. Patients who wish to undergo in-office repair must be able to maintain the surgical position and tolerate awake manipulation of the external auditory canal (EAC). Patients who have significant anxiety around medical procedures may not be well suited to this technique. Table 53.1 has a list of in-office repair indications and contraindications.
Small central anterior tympanic membrane perforation is well suited to in-office repair.
Table 53.1
In-Office Repair Indications and Contraindications
| Indications for In-Office Repair | Contraindications for In-Office Repair |
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Table 53.2
Suggested Materials for In-Office Tympanoplasty
| Instruments | Supplies |
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Technique
Patient preparation : Patients are first seen in the clinic exam room to obtain informed consent, review the steps of the procedure, and discuss potential risks. A discussion of risks includes persistent hearing loss, nonhealing perforation, late reperforation of the TM, otorrhea, and perioperative pain. General risks associated with ear surgery should also be discussed, though these risks are low: new or worsening hearing loss, dizziness, tinnitus, and cholesteatoma formation.
The TM is then examined to confirm the size of the perforation and the absence of active infection, and at this point, the surgeon can begin anesthetization of the ear.
A topical local anesthetic consists of lidocaine 4% jelly on sterile cotton balls, which are placed in the ear canal adjacent to the TM and left for approximately 15 minutes. Care should be taken not to deliver lidocaine jelly into the middle ear, as this can result in temporary but severe vertigo. The patient is then placed supine on the procedure room table, and the cotton balls are removed. The ear is prepped with Betadine and draped with sterile towels. An additional 1–2 cc of 1% lidocaine with epinephrine 1:100,000 may be injected into the posterior superior ear canal skin at the bony cartilaginous junction.
Equipment and instruments : Most of the necessary instruments for this procedure are typically available at otolaryngology clinics, including a reclining chair or procedure table with an adjustable back.
A rigid Hopkins rod telescope coupled to an HD or 4K video camera may provide improved visualization for the procedure; however, if an endoscope is not available, traditional binocular microscopy is adequate for most cases unless the perforation is anterior and the overhang is prominent. Endoscopic equipment includes a 3- or 4-mm diameter, 14-cm rigid 0-degree endoscope with 3CCD HD or 4K video camera, fiberoptically delivered light source, and tower with monitor and video recording system. A high-definition monitor can increase patient comfort as they can observe the procedure and anticipate the steps of the repair. The following are also suggested: antifog solution, a sterile camera drape, and sterile towels. Oxymetazoline may be helpful for hemostasis if the ear canal is inadvertently traumatized.
Other instruments may include: otologic micro-suctions (3, 5, and 7 French), nontoothed forceps, 4, 5, and 6-mm biopsy punches, iris scissors, cup forceps, smooth alligator forceps, a curved needle, cerumen loop, and a round knife. Additionally, two small basins for sterile saline and antibiotic suspension, Gelfoam for packing of the EAC at the end of the procedure, and a merocele wick for the ear are also needed. Porcine small intestinal submucosa (Otologic Repair Graft, Cook Medical) may be used as an off-the-shelf graft material. Other commercially available graft materials may be used instead, depending on what is cost-effective and available for the clinic. Additional graft materials include: paper patches (rice paper, cigarette paper, etc.), silk fibroin, Steri-strip, gelatin sponge, hyaluronic acid (EpiFilm/EpiDisk, Medtronic), growth factors, bacterial cellulose, protease-solubilized collagen, and silicone foil.
Graft preparation : The perforation should first be measured under the microscope or endoscope. Once the perforation size is determined, under sterile conditions, a 4-, 5-, or 6-mm punch biopsy is used to obtain two circular grafts of the porcine small intestinal submucosa. The diameters of the grafts should be 1–2 mm greater than the perforation. Linear cuts should be made opposite each other in the 12 and 6 o’clock positions, with a 0.5 mm bridge left between them. The two grafts are then interdigitated with two flanges in the medial plane and two in the lateral plane ( Fig. 53.2 ). The graft is then placed in a sterile saline solution until needed.
