 An Overview

Mary Sutton, cst, cfa

OVERVIEW ost ear procedures are performed to restore or improve hearing, M although to relieve are also common. This article will begin with an overview of ear anatomy and the physiology of hearing, followed by a presentation of the equipment, instruments and supplies typically used in ear surgeries. The focus of the article will then turn to a discussion of five common procedures: myringot- omy with tube insertion, tympanoplasty, ossicular recon- struction, tympanomastoidectomy and .

ANATOMY OVERVIEW The ear consists of three anatomic regions: the external, middle and . With the exception of the auricle, the ear structures are contained with- in the temporal bones on each side of the skull and are surrounded by the mastoid air cells, which are part of the temporal bones. Below the mastoid is the sigmoid sinus, which is filled with venous blood and drains into the internal jugular vein. The facial nerve (cranial nerve VII) travels through the temporal bone and exits in front of the ear to innervate the face. The facial nerve has two branches in the : one branch innervates the , which moves the , and the other branch (the chorda tympani) is a taste sensor for the tongue.

EXTERNAL EAR The external ear is composed of the outer appendage, called the auricle or pinna, and the external auditory canal. There is a small, protruding carti- laginous outgrowth (), which protects the opening of the external auditory canal.

FEBRUARY 2007 The Surgical Technologist 61 278 FEBRUARY 2007 1 CE CREDIT

Glands that produce cerumen are embedded INNER EAR in the walls of the canal. Cerumen acts as a lubri- The oval window is one of two membranes sepa- cant and also traps dead skin cells and foreign rating the middle and inner ear. The oval window matter, which are then expelled from the canal transmits sound waves from the footplate of the with the help of cilia. The external ear ends at the stapes to the fluid contained within the vestibule lateral aspect of the tympanic membrane. of the inner ear. The vestibule contains the utricle and saccule—the sense organs for balance—and MIDDLE EAR connects the two divisions of the inner ear. The middle ear begins at the medial aspect of The first division consists of the semicircu- the tympanic membrane or , which lies lar canals that function in the maintenance of across the inner aspect of the external auditory balance, and the second division consists of the canal. The tympanic membrane is cone-shaped, cochlea, which contains the organ of Corti that

FIGURE 1: Anatomy of the ear. Temporal bone Malleus (hammer) Incus (anvil) Semicircular canals Stapes (stirrup) Vestibular nerve (VIII) Facial nerve

Auricle (or pinna) Cochlear nerve

Cochlea External acoustic meatus Round window

Auditory Lobe (eustachian) tube Tympanic membrane (eardrum) Mastoid process Facial nerve

with its convexity facing downward and outward functions in hearing. Branches of the vestibu- toward the auditory canal. locochlear nerve (cranial nerve VIII) transmit The three auditory within the middle information concerning sound and balance to ear are the malleus, incus and stapes. The handle the brain for interpretation. of the malleus rests against the tympanic mem- The round window is the second membrane brane, causing its conical protrusion. Ligaments that separates the middle and inner ear. This win- attach its head to the body of the incus. dow relieves pressure in the inner ear by bulging The incus articulates with the head of the sta- outward (into the middle ear) when necessary. pes, and the base—or footplate—of the stapes rests in the oval window. The PHYSIOLOGY OF HEARING drains fluid from the middle ear to the naso- Hearing, which is a mechanoreceptive sense, is pharynx and allows for pressure equalization made possible by the ear’s response to the mechan- within the middle ear. ical vibrations of sound waves through the exter-

62 The Surgical Technologist FEBRUARY 2007 nal auditory canal toward the tympanic mem- angled or straight eyepieces for the microscope. brane. Sound is funneled into the external auditory In some hospitals, the microscope is connected canal by the pinna to the tympanic membrane and to video equipment, enabling the surgical tech- amplified as it moves through the narrowing canal. nologist to view the procedure and anticipate the Sound waves strike the tympanic membrane, caus- surgeon’s needs more effectively. ing it to vibrate, which subsequently causes the Some surgeons use an adjustable, hydraulic ossicles of the middle ear to vibrate. chair when looking through the microscope. A The ossicles are suspended by ligaments that facial nerve monitor may be used to prevent inju- allow the malleus and incus to act as a single ry to the facial nerve, particularly during stape- lever, with its fulcrum approximately at the bor- dectomies and cochlear implant procedures. der of the tympanic membrane. The head of the Several different sizes of round cutting and malleus, which is opposite its handle, balances diamond burrs should be available to give the the other end of the lever, so that changes in body surgeon options. Lasers may be used for stape- position do not cause fluctuations in tension on dectomies or to remove scar tissue and choles- the tympanic membrane. teatoma from the middle ear. The handle of the malleus is held in a con- stant state of being pulled inward by ligaments INSTRUMENTS and by the tensor tympani muscle, which keeps Most hospitals have a general ear set with larger the tympanic membrane tense. Such conditions instrumentation, such as ear specula (all sizes), a allow vibrations acting on any portion of the specula holder, retractors (eg, angled or hinged tympanic membrane to be transmitted to the Weitlaner, mastoid (Jansen) and Senn), House malleus. The incus moves in concert with the suction tips (usually 3, 5 and 7 Fr and 20 and malleus because the two are tightly bound to one 22 ga), scalpel handle, tissue forceps, hemostats, another by ligaments. needle holders, periosteal elevator and dissect- The articulation of the ossicles with one ing scissors. Some hospitals have surgery-spe- another is such that the stapes presses on the cific instrument sets, and some surgeons have fluid of the inner ear each time the incus moves their own sets of instruments. inward. When the malleus moves outward, the Some of the microsurgery instruments have stapes pulls on the fluid within the cochlea. As dedicated trays to prevent damage. Ear picks the fluid moves, hair cells within the cochlea are also may have a special tray, which can be placed stimulated and send nerve impulses from the on the Mayo stand for convenience. cochlear branch of the vestibulocochlear nerve It is important to clean off the instrument tips to the temporal lobe of the brain—culminating with a microwipe sponge after they are handed in the sensation of hearing. back to you. This helps the surgeon see the end of the instrument more clearly through the micro- COMMONLY USED EQUIPMENT, scope and thus determine more accurately the INSTRUMENTS AND SUPPLIES depth to which it should be inserted. The following three sections present a general There are numerous ear picks available, so they list of items commonly used in ear surgeries. As should chosen according to surgeon preference. in all procedures, consult each surgeon’s prefer- Micro-cup and alligator forceps are typically ence card. used. Many surgeons use a small, smooth alliga- tor forceps to prevent damage during placement EQUIPMENT of prostheses. Bellucci and Glasscock scissors A microscope is used in most ear procedures. A also may used. 250-mm lens is most commonly used, but some Some surgeons, especially for stapedec- surgeons may use a 300-mm lens as well. Con- tomies, prefer a special speculum holder that sult the preference card to see if the surgeon uses attaches to the operating table.

FEBRUARY 2007 The Surgical Technologist 63 Most tubes stay in the eardrum approximately four months and then fall out, after which time the tympanic membrane heals. T-tubes are designed for long-term use, and grommet tubes are designed for short-term use. Once tympanostomy tubes are placed, the patient must take care to prevent water from entering the and traveling to the middle ear.

INSTRUMENTATION

CFA A set usually includes a myringot- , CST omy blade handle; large and small alligator for- ceps; a Rosen needle or middle ear pick; House suction tips in sizes 5 and 7 Fr and 20 ga; a ceru-

Photo courtesyPhoto Mary Sutton, of men loop or curette; and a set of ear specula, usually in sizes 4, 4.5 and 5 mm. FIGURE 2: SUPPLIES Equipment needed includes a microscope Myringotomy set-up. If a microscope is used for a sterile procedure, with a 250-mm lens, suction tubing, towels and then a sterile drape is needed. Cotton balls may cotton balls. be used either as a dressing or as a sponge. Occa- Myringotomy is considered a clean proce- sionally, a hemostatic agent may be applied with dure. No patient preparation is performed, and a portion of a cotton ball. An absorbable gelatin draping is optional. If a drape is used, it may be a sponge may be used as a hemostatic agent or as small fenestrated sheet or towels. packing to secure graft material. Author’s tips: 1. Suction tips can become clogged Commonly used medications include topical easily. It’s a good idea to have two suction tips in adrenaline, lidocaine (with or without epineph- each size on your set-up, as well as some saline and rine) and an antibiotic otic suspension. a syringe to remove serous fluid build-up. 2. When selecting specula, keep in mind that some physio- INSERTION logical conditions affect ear canal size. For exam- Myringotomy with insertion of tympanostomy ple, some patients with Down syndrome have small tubes is the most common operation in the Unit- ear canals and thus require smaller specula. ed States with approximately two million proce- dures per year. PROCEDURAL OVERVIEW This procedure may be performed with ster- INDICATIONS FOR SURGERY ile gloves but without a sterile gown, according The most common indication for placement of to hospital policy. Surgeons should remove the tympanostomy tubes is chronic media powder from their gloves before handling the with effusion. Other indications include recur- instruments to prevent the introduction of pow- rent , retraction of the tympanic der into the ear. membrane, and a collapsed eustachian tube. The surgeon drapes per individual routine and places the speculum in the ear canal. The micro- TUBE SELECTION scope is focused on the tympanic membrane. A Several factors influence the choice of tympa- cerumen loop or curette or a large suction tip is nostomy tubes: surgeon preference, the size of used to remove wax or debris from the ear canal. the child’s ear canal, the length of time the tubes An incision is made in the tympanic membrane are expected to remain in position, the condition with a myringotomy blade, and a smaller suction is of the eardrum, and the condition of the ossicles. placed through the incision to remove any fluid in

64 The Surgical Technologist FEBRUARY 2007 the middle ear. In some cases, a thick serous fluid, clearly. A rotating drill and facial nerve monitor called “glue,” is found, and then a larger suction tip are commonly used, according to surgeon pref- may be necessary to evacuate this fluid. erence. A variety of burrs for the drill and a spec- Once the middle ear is clear, the tympanos- ulum holder should be available. tomy tube is placed into the incision with a small Typically, a general ear set and a microsurgery alligator forceps. The tube is then seated prop- ear set with ear picks are used. Beaver blades are erly with a Rosen needle or middle ear pick, and commonly used and are selected according to sur- the speculum is removed. If necessary, antibiotic geon preference. otic suspension is applied to the ear canal, and a Supplies include nonsterile and sterile prep- small cotton ball is placed in the external canal aration items, appropriate basins and drapes to prevent drainage. (including drapes for the microscope and the The patient is repositioned, and the surgeon back of the hydraulic chair), electrosurgical pen- moves to the other side of the table to repeat the cil with dispersive electrode and holster, suction procedure on the contralateral side, if necessary. tubing, ear bulb syringe, razor and hair restraint (eg, a bouffant cap secured with tape). POTENTIAL COMPLICATIONS Author’s tip: In the author’s experience, a 3-cc The most frequent complication following tym- syringe with a 27-ga needle is often used to inject panostomy tube insertion is otorrhea, character- medications, and a 12-cc syringe should be on the ized by serous fluid draining from the ear, often field to unclog suction tips, if necessary. due to water contamination of the middle ear. Other supplies commonly used include absorb- Other complications include tympanosclerosis able gelatin, lidocaine, epinephrine and antibiotics. (often due to repeated tube placement), persis- tent tympanic membrane perforation (the inci- PROCEDURAL OVERVIEW dence of which increases with long-term tube A nonsterile setup is prepared according to sur- placement), and cholesteatoma. geon preference. The patient is placed in the supine position with the head turned so that the TYMPANOPLASTY operative ear is turned upward. The operating Reconstruction of the tympanic membrane is table may be turned 90 to 180 degrees to accom- usually indicated in cases of membrane perfora- modate the surgical team and equipment. tion. Initially, full- or split-thickness skin grafts Author’s tip: The blood pressure cuff should from the postauricular area were used to repair not be placed on the same arm as the affected ear, perforations. The major disadvantages of using because the inflating and deflating may cause this type of graft were excessive desquamation unwanted movement. and reperforation, therefore creating the need for The patient is prepped and draped according to an alternative grafting material as well as a sec- surgeon preference. Drape the microscope as soon ond operation. as possible, because it will be used immediately. Surgeons then tried ear canal skin and var- After gowning and gloving, make sure that powder ious connective tissue grafts, with the connec- is removed from the gloves of all surgical staff. tive tissue grafts becoming extremely prevalent The surgeon will place the speculum in the in the early 1960s. Most surgeons today use the canal and excise a “vascular strip,” typically with temporalis fascia as a graft. a beaver blade and a local anesthetic. The vascular strip is a section of tissue taken from the ear canal INSTRUMENTATION or ear drum and placed over the temporalis fascia Equipment typically needed includes a micro- graft later on in the procedure to improve healing. scope with a 250-mm lens, adjustable chairs for If tissue is taken from the ear drum, the the seated team members, and a video monitor remaining tympanic membrane usually is dissect- placed where the surgical technologist can see it ed, or the perforation is trimmed (or rimmed).

FEBRUARY 2007 The Surgical Technologist 65 Some surgeons perform a tympanoplasty ABOUT THE AUTHOR through the ear canal, while others use a postauric- Mary Sutton, cst, cfa, is currently a staff sur- ular approach. Surgeon preference and the pathol- gical technologist and the oral/ENT coordina- ogy of the area determine the approach. tor at Shands AGH in Gainesville, Florida. She With both approaches, a small incision will was certified as a CST in 1984 and as a CFA in be made from near the top of the ear to the tem- 1994. She has been a member of AST since 1984 poralis fascia to retrieve the graft. The tissue is and served as vice president of the Florida State removed and prepared according to surgeon Assembly from 1999 through 2003. She served preference, and the incision is closed. on the AST Board of Directors from 1996 to In some cases, the tissue is compressed with a 2000 and currently serves on the NBSTSA Board fascial press or flattened on a Teflon® block with of Directors. a sponge. The fascia may be left in the press or removed to dry until placement. Editor’s note: This article will continue in next The graft is cut to fit and placed in the ear month’s issue. In Part II, the author will contin- canal with a small, smooth alligator forceps and ue her overview of aural surgeries by focusing on an ear pick. The vascular strip removed earlier three procedures: ossicular reconstruction, tym- is laid over the temporalis fascia graft. Cut piec- panomastoidectomy and stapedectomy. es of moist, absorbable gelatin may be used to secure the graft and to create a bed that supports References the graft. 1. Alford BR. Department of Otolaryngology—Head and To prevent drainage, additional gelatin may Neck Surgery, Baylor College of Medicine, Houston, Texas. Available at: http://www.bcm.tmc.edu/oto. be placed in the ear canal, usually with a small Accessed January 5, 2007. alligator forceps or with a small suction tip and 2. Chaffee EE, Lytle IM, eds. Basic Physiology and Anato- ear pick. A cotton ball is often placed in the exter- my, 4th ed. Lippincott; Philadelphia, Pa:1980. nal ear canal to prevent liquid from leaking out. 3. Cummings CW, ed. Otolaryngology—Head and Neck While placing the graft in the ear canal, the Surgery, Vol 1-3, 2nd ed. Mosby; St Louis, Mo:1993. surgeon may ask the anesthesia provider to stop 4. Fisch U. Tympanoplasty, Mastoidectomy, and Sta- using nitrous oxide, which can cause pressure pes Surgery, 2nd ed. Thieme Medical Publishers; New York, New York:1994. on the eardrum which may cause the graft not to 5. Gray H. Gray’s Anatomy, 15th ed. Chancellor Press; 1992. seat properly on the membrane or vascular strip. 6. Kennedy (Sutton) M. Cochlear Implants and Sensori- If the patient has a small ear canal, the sur- neural . Association of Surgical Technologists geon may do a Sheehy tympanoplasty, which (AST) Continuing Education Independent Study Series. involves removing the ear canal skin and enlarg- Association of Surgical Technologists; Centennial, ing the canal with an ear drill. A full thickness Colo:1996. 7. Lore JM, ed. An Atlas of Head and Neck Surgery, 3rd ed. skin graft may be placed in the canal if extra skin WB Saunders; Philadelphia, Pa:1988. is needed to supplement the existing skin. When 8. Montgomery WW. Surgery of the Upper Respirato- using the ear drill, make sure appropriate irri- ry System, 3rd ed. Williams and Wilkins; Baltimore, gation is done, so that the bone will not become Md:1996. overheated and damaged. 9. Myers EN. Operative Otolaryngology—Head and Neck Surgery, 1st ed. WB Saunders; Philadelphia, Pa:1997. 10. Price P, Frey K, Junge T, eds. Surgical Technology for POTENTIAL COMPLICATIONS the Surgical Technologist. 2nd ed. Thomson Delmar The most common complication of tympano- Learning; Clifton Park, NY:2004. plasty is reperforation. Other complications include hemorrhage, infection and unsuccess- Teflon is a registered trademark of DuPont. ful restoration of the patient’s hearing. In rare cases, a patient may have to undergo several pro- cedures before the graft epithelializes.

66 The Surgical Technologist FEBRUARY 2007 1. Which of the following is not a retrac- 6. A ______should be used to clean tor commonly used in aural surgeries? microsurgery instruments. a. Jansen a. Chamois CEExam278 FEBRUARY 2007 1 CE CREDIT b. Senn b. Gauze c. Taylor c. Microwipe d. Weitlaner d. None of the above.

2. The ______allows for pressure 7. Which of the following tubes is equalization within the middle ear. designed for long-term use? a. Auricle a. T-tube b. Cilia b. Grommet Ear surgery– c. Stapedius c. Lewis an overview d. Eustachian tube d. Martin 3. ______scissors are shaped like a 8. The three auditory ossicles include all Earn CE credits at home bayonet. of the following except… You will be awarded continuing education (CE) credit(s) for a. Glasscock a. Stapes recertification after reading the designated article and com- b. Bellucci b. Malleus pleting the exam with a score of 70% or better. c. Strabismus c. Mastoid If you are a current AST member and are certified, credit d. Busch d. Incus earned through completion of the CE exam will automatically be recorded in your file—you do not have to submit a CE report- 4. ______is an indication for 9. Nitrous oxide may be stopped during ing form. A printout of all the CE credits you have earned, includ- tympanoplasty tube insertion. tympanoplasties, due to the risk of… ing Journal CE credits, will be mailed to you in the first quarter a. Cholesteatoma a. Effusion following the end of the calendar year. You may check the status b. Tympanic membrane perforation b. Reperforation of your CE record with AST at any time. c. c. Bone necrosis If you are not an AST member or are not certified, you will be d. Chronic otitis media d. Pressure on tympanic membrane notified by mail when Journal credits are submitted, but your credits will not be recorded in AST’s files. 5. The ______fascia is typically used 10. ______often occurs following Detach or photocopy the answer block, include your check or as graft tissue in tympanic membrane repeated tube placement. money order made payable to AST, and send it to the Accounting reconstruction. a. Tympanosclerosis Department, AST, 6 West Dry Creek Circle, Suite 200, Littleton, CO a. Obturator b. Excess cerumen 80120-8031. b. Temporalis c. Desquamation c. Tyrrell’s d. Effusion Members: $6 per CE, nonmembers: $10 per CE d. Visceralis

278 FEBRUARY 2007 1 CE CREDIT Ear surgery–an overview a b c d a b c d

Q Certified Member Q Certified Nonmember 1 Q Q Q Q 6 Q Q Q Q

Certification No. ______2 Q Q Q Q 7 Q Q Q Q

Name ______3 Q Q Q Q 8 Q Q Q Q

Address ______4 Q Q Q Q 9 Q Q Q Q

City ______State ______ZIP______5 Q Q Q Q 10 Q Q Q Q

Telephone ______Mark one box next to each number. Only one correct or best answer can be selected for each question. FEBRUARY 2007 The Surgical Technologist 67