OPERATING ROOM

The OR for otologic surgery requires features that differ from ORs used for nonotologic surgery. The following sections elaborate on the general environment of the OR designed for ear surgery. A word about the sterile field is in order. Respecting the sterile field is vital during routine otologic surgery, and takes on special significance during neurotologic procedures. Maintaining the proper environment means limiting traffic through the OR, and keeping the number of visitors to a minimum. It is preferable for observers to be in a remote room watching the procedures on video. Individuals allowed in the OR should be experienced in sterile technique and should wear jackets over scrubs so that all skin surfaces are covered (Fig. 1-1).

FIGURE 1-1 Observer in jacket.

Before entering the OR, the patient identifies the operative site. The correct ear is marked using a marking pen. The psychological environment of the OR must be respected because many otologic procedures are performed on awake patients under local anesthesia. Members of the surgical team and visitors must use discretion when making comments during surgery.

The first piece of OR equipment to be discussed is the operating table. The surgeon must be comfortable while performing microsurgery. Adequate leg room under the table can be achieved with older OR tables by placing the patient 180 degrees opposite the usual position; in other words, the patient’s head is where the feet would normally be (Fig. 1-2). Newer electric tables easily accommodate the patient and surgeon. Because most otologists spin the OR table 180 degrees after the induction of anesthesia, the new tables allow for spinning the table without unlocking it. Nonetheless, after the patient is properly positioned, the table must be firmly locked in place.

FIGURE 1-2 Operating table with patient’s head at foot of bed.

All ORs are equipped with wall suction. Standard suction devices are acceptable for otologic surgery. It is preferable, however, to use a multiple-canister suction setup, minimizing the number of times the bottles must be emptied (Fig. 1-3). Suction systems have several locations where the amount of suction can be varied, but the surgeon should also employ a control clamp on the suction tubing on the sterile field (Fig. 1-4).

FIGURE 1-3 Multiple-canister suction setup.

FIGURE 1-4 Suction tubing with control clamp.

The tubing that is attached to the suction tips and suction irrigators should be highly flexible. The readily available disposable tubing is not flexible enough for microsurgery, and places awkward torque on the surgeon’s hands. Suction setup problems are common in every OR. The prudent team troubleshoots the system in advance and has access to backup equipment.

Electrocautery equipment should be in a ready-to-use state on all procedures except perhaps stapes surgery. The patient must be properly grounded. It is advantageous to have unipolar and bipolar cautery on the field for all chronic ear and neurotologic procedures. Polytef (Teflon) tips are available for most cautery devices and are desirable. Surgeons have at their disposal a wide array of safe cautery devices, but they must be thoroughly familiar with these electric instruments before use.

The surgical drill is another essential piece of equipment for otologic surgery. The vast array of available drills precludes an in-depth discussion of each system. Generally, otologic drills fall into two categories: air driven and electric. There are advantages and disadvantages to each type, and most surgeons have a distinct preference based on training and experience. For surgeons using air-driven drills, it is preferable to use a central source of nitrogen to power the drill, instead of using room tanks of the gas. Using a central source eliminates the need for changing tanks during long cases.

High-speed drills capable of doing most of the bone work in the temporal bone include the Fisch, Midas Rex, and Anspach drill systems. These drills generally are unsuitable for work in the middle ear, especially around the stapes footplate. For the latter purposes, a microdrill, such as the Skeeter drill or Synergy, is suitable (Fig. 1-5). Whatever drill is used in the middle ear, it must have a variable speed control and a wide array of drill bits.

FIGURE 1-5 Synergy microdrill for footplate work.

Most larger otologic drills are equipped with straight and angled handpieces. Most surgeons prefer straight handpieces for early gross removal of the mastoid cortex, switching to angled handpieces for working deeper in the temporal bone. The Anspach drill system has a handpiece that can be converted from straight to angled simply by rotating the connection. A full complement of cutting and diamond burrs is mandatory. Figure 1-6 shows the Anspach drill system. Most drill systems have attachments that vary in shape, diameter, and length. It is the surgeon’s responsibility to be intimately familiar with the drill system and to have all of the attachments and burrs that might be needed.

FIGURE 1-6 Anspach drill system.

The otologic drill should be held in the hand like a pencil, with the hand resting comfortably on the sterile field. The side of the burr should be used to provide maximum contact between the bone and the flutes of the burr, affording safer and more efficient drilling (Fig. 1-7). The newer drills are remarkably reliable, but, similar to other tools, may malfunction. Drill systems require proper care and inspection before use. A backup system should be readily available.

FIGURE 1-7 Proper holding of the drill.

The introduction of the operating microscope revolutionized otologic surgery. Most otolaryngologists are familiar with the use of the microscope. Several brands of optically superior instruments are available; most are sufficiently similar to share the same general principles.

The otologic surgeon must be familiar with the adjustments on the microscope, and must be prepared to troubleshoot the problems that may arise with the scope. The focal length of the objective lens is a matter of personal preference. Most otologists use a 200 mm or 250 mm objective. If a laser is attached to the microscope, one might consider a 300 mm objective. The objective lens should be selected, confirmed, and properly mounted before draping the microscope. Other adjustments, such as the most comfortable interpupillary distance, also should be done before the scope is draped. Par focal vision should be established so that the surgeon can change magnification without having to change focus. This is accomplished by first setting the diopter setting of both eyepieces to zero. The 40× magnification (or highest available setting) is selected. The locked microscope is focused on a towel using the focus knob only. Without disturbing any of the settings, the magnification is now set at 6× (or the lowest available setting). The eyepieces are individually adjusted to obtain the sharpest possible image. The diopter readings are recorded for future use. The surgeon should have par focal vision when these appropriate eyepieces are used.

The microscope should move easily. All connections should be adjusted so that the microscope does not wander by itself, yet permits movement to any position with minimal effort. Wrestling with the microscope during microsurgery is an extreme distraction.

Proper posture at the operating table is crucial. To perform microsurgical procedures, rule number one is that the surgeon must be comfortable. The surgeon should be seated comfortably in a proper chair with the back support at the correct height. Both feet should be resting comfortably on the floor. Fatigue is avoided by assuming a restful position in the chair, rather than a rigid upright posture (Fig. 1-8).

FIGURE 1-8 A, Proper posture for the surgeon. B, Wrong posture for the surgeon.

The overall OR setup for routine otologic surgery is shown in Figure 1-9. For neurotologic surgery, more space must be available for additional equipment. Middle cranial fossa procedures require some modifications to the OR setup (Fig. 1-10). Basically, the surgeon and the microscope trade places such that the surgeon is seated at the head of the table. Cooperation and careful orchestration between the surgeon, nursing personnel, and anesthesiologist are required for otologic surgery. The needs of the otologist are best served by having the anesthesiologist at the foot of the bed and the scrub nurse opposite the surgeon. Space for the facial nerve monitoring equipment and personnel is reserved.

FIGURE 1-9 Usual otologic/neurotologic operating room setup.

FIGURE 1-10 Operating room layout for middle fossa surgery.

STAPES SURGERY

The following description of the instrumentation and operative setup for stapes surgery also provides information useful for other middle ear procedures. Under most circumstances, it is preferable to perform stapes surgery under local anesthesia, and surgeons who do so usually employ some type of preoperative sedation. Numerous regimens are available, and their description is beyond the scope of this text. If sedation is administered by the surgeon or nursing personnel, without the assistance of an anesthetist or anesthesiologist, the agents used should be short-acting and reversible.

It is far safer for the patient to be psychologically prepared for the procedure than to be oversedated. At the House Clinic, the associates prefer to perform all local anesthesia cases (including stapes surgery) under monitored anesthesia care. This approach requires the presence of anesthesia personnel in the OR to sedate the patient, as is required for the operation, and to monitor vital functions. The surgeon is relieved from this duty, allowing total concentration on the microsurgery.

About 30 minutes before the operation, the patient is brought to the preoperative holding area. If the surgeon routinely harvests a postauricular graft, this area is now shaved. A plastic aperture drape is applied to the operative site and trimmed so as not to cover the patient’s face (Fig. 1-11). An intravenous line is started, and the patient is now ready to go to the OR. When the patient is on the OR table, the monitors are placed on the patient by the nursing or anesthesia staff. Minimal monitoring includes pulse oximetry, automatic blood pressure cuff, and electrocardiogram electrodes. The ear and plastic drape are scrubbed with an iodine-containing solution, unless the patient is allergic to iodine. A head drape is applied, and the ear is draped with sterile towels so as not to cover the patient’s face; this can be facilitated by supporting the drapes with a metal bar attached to the OR table, or by fixing the drapes to the scrub nurse’s Mayo stand (Fig. 1-12).

FIGURE 1-11 Plastic drape applied for stapes surgery.

FIGURE 1-12 Patient draped in the operating room for stapes surgery.

The patient’s head is now gently rotated as far away from the ipsilateral shoulder as possible, and the table is placed in slight Trendelenburg position. These maneuvers increase the surgeon’s working room and help to straighten the external auditory canal (EAC). The EAC is gently irrigated with saline heated to body temperature. Vigorous cleaning of the canal is avoided until the ear is anesthetized. The local anesthesia is administered with a plastic Luer-Lok syringe that has finger and thumb control holes. A 1½ inch, 27 gauge needle is firmly attached to the syringe. If the ear is injected slowly and strategically, excellent anesthesia and hemostasis can be achieved with a solution of 1% lidocaine with 1:100,000 epinephrine (e.g., 1:40,000). When using stronger concentrations of epinephrine, the patient’s blood pressure and cardiac status must be considered, in addition to the possibility of mixing errors.

The canal is injected slowly in four quadrants starting lateral to the bony-cartilaginous junction. The final injection is in the vascular strip. If one routinely harvests fascia or tragal perichondrium, these areas are now injected.

Before describing stapes surgical instruments, a few general comments are in order. All microsurgical instruments should be periodically inspected to ensure sharp points and cutting surfaces. The instruments for delicate work should have malleable shanks, enabling the surgeon to bend the instruments to meet the demands of the situation.

If the surgeon prefers a total stapedectomy over the small fenestra technique, an oval window seal must be selected. If fascia is used, the tissue is harvested before exposing the middle ear. The tissue is placed on a Teflon block or fascia press to dry. If perichondrium is preferred, this may be harvested immediately before footplate removal. For the small fenestra technique, a small sample of venous blood is obtained when the intravenous line is started. This blood sample is passed to the scrub nurse and placed in a vial on the sterile field.

Various ear specula should be available in oval and round configurations. Sizes typically range from 4.5 to 6.5 mm (Fig. 1-13). It is desirable always to work through the largest speculum that the meatus permits, without lacerating canal skin. Some surgeons prefer to use a speculum holder for stapes and other middle ear procedures. The tympanomeatal flap is started with incisions made at the 6 and 12 o’clock positions with the No. 1, or sickle, knife. These incisions are united with the No. 2, or lancet, knife. This instrument actually undermines the vascular strip instead of cutting it. The strip is cut with the Bellucci scissors. The defined flap is elevated to the tympanic annulus with the large round knife, known as the large “weapon.” When properly identified, the annulus is elevated superiorly with the Rosen needle, and inferiorly with the annulus elevator, or gimmick. Figure 1-14 shows a typical set of stapes instruments, including suction tips.

FIGURE 1-13 Speculum array.

FIGURE 1-14 Stapes instruments

Adequate exposure usually requires removal of the bony ledge in the posterosuperior quadrant. This can be initiated with the Skeeter microdrill and completed with a stapes curette (Fig. 1-15).

FIGURE 1-15 Stapes curette.

From this point on, the steps differ depending on the technique preferred by the surgeon. The diagnosis of otosclerosis should be confirmed on entering the middle ear, and a measurement should be taken from the long process of the incus to the stapes footplate with a measuring stick. The next step is to make a control hole in the footplate with a sharp pick-needle (Barbara needle) or the laser. The incudostapedial joint is separated with the joint knife, the tendon is cut with scissors or laser, and the superstructure is fractured inferiorly and extracted.

For work on the footplate, the surgeon must have a variety of suitable instruments available. A stapedotomy can be created with a microdrill, laser, or needles and hooks. The 0.3 mm obtuse hook is useful for enlarging the fenestra.

For total footplate extraction, a right angle hook or excavator (Hough hoe) is used. The harvested graft is guided into place with a footplate chisel. The prosthesis is grasped with a smooth alligator or strut forceps and placed on the incus. It is positioned on the graft, or into the fenestra, with a strut guide. The wire is secured onto the incus with a crimper, or wire-closing forceps. The McGee crimper is useful, especially if followed by a fine alligator forceps for the last gentle squeeze. A small right angle hook may be necessary to fine-tune the position of the prosthesis (Fig. 1-16).

FIGURE 1-16 Crimpers and footplate hook.

Suction tubes for stapes surgery include Nos. 3 to 7 Fr Baron suctions plus Rosen needle suction tips (18 to 24 gauge) with the House adapter (Fig. 1-17). The Rosen tips are useful when working near the oval window, with the surgeon’s thumb off the thumb port.

FIGURE 1-17 Rosen suction tubes with House adapter; Baron tubes.

Ear packing after stapes surgery is accomplished with an antibiotic ointment to hold the flap in place. A piece of cotton suffices as a dressing, unless a postauricular incision has been made, in which case a mastoid dressing is applied.

For all middle ear procedures, the surgeon should hold the instruments properly. The instrument should rest, like a pencil, between the index finger and thumb, allowing easy rotation around the shank. The hands should always be resting on the patient and the OR table. The middle and ring fingers should rest on the speculum so that the hand moves as a unit with the patient. Proper hand position and holding of instruments should afford the surgeon an unimpeded view (Fig. 1-18).

FIGURE 1-18 Proper holding of instruments as shown by Dr. William House.

TYMPANOPLASTY AND TYMPANOPLASTY WITH MASTOIDECTOMY

The preparation and draping for tympanoplasty with or without mastoidectomy are much the same as for stapes surgery. The major difference is the amount of hair shaved before draping. Usually, enough hair is shaved to expose about 3 to 4 cm of skin behind the postauricular sulcus. The plastic drape is applied to cover the remaining hair (Fig. 1-19).

FIGURE 1-19 Drape (3M 1020) applied for chronic ear surgery.

The patient is positioned on the OR table as described earlier. Whether the procedure is performed under local or general anesthesia depends on the extent of the surgery, the surgeon’s preference, and the desire of the patient. After appropriate sedation or induction of anesthesia, the ear and plastic drape are scrubbed with the proper soap or solution. Some surgeons place a cotton ball in the meatus if a perforation exists, preferring not to allow the preparation solution to enter the middle ear. The field is draped as described earlier, the head is rotated toward the contralateral shoulder, and the table is placed in slight Trendelenburg position (Fig. 1-20