E-Book, Englisch, 408 Seiten, ePub
E-Book, Englisch, 408 Seiten, ePub
ISBN: 978-3-13-257863-0
Verlag: Thieme
Format: EPUB
Kopierschutz: Wasserzeichen (»Systemvoraussetzungen)
"Written by a master in his field.can be regarded as the standard reference and surgical guide for this subject."--The Annals of the Royal College of Surgeons of England
This successor to the author's standard-setting, problem-solving manual on tympanoplasty contains step-by-step illustrations of surgical techniques that have proven valuable during 30 years of experience. The illustrations were drawn by the author himself and provide the details essential for a firm understanding of each procedure. The book describes the principles underlying the surgical techniques in detail, and results are presented and discussed.
Features:
Updated coverage of titanium prostheses, new meatoplasty techniques, malleostapedotomy, cochlear implants, and the use of imaging techniques for planning and evaluating surgical procedures
Bullet-point lists of surgical highlights
850 simple line drawings to demonstrate technical manuevers and surgical concepts in a step-by-step fashion
Zielgruppe
Ärzte
Autoren/Hrsg.
Fachgebiete
Weitere Infos & Material
Part 1 Tympanoplasty (Closed Cavity)
Chapter 1 Tympanoplasty
Chapter 2 Myringoplasty, Meatoplasty, and Canalplasty
Chapter 3 Ossiculoplasty
Chapter 4 Special Applications with Tympanoplasty
Part 2 Mastoidectomy (Open Cavity)
Chapter 5 Mastoidectomy and Epitympanectomy
Chapter 6 Special Applications of Mastoidectomy
Part 3 Stapes Surgery
Chapter 7 Stapedotomy and Stapedectomy
Chapter 8 Special Applications of Stapes Surgery
Part 4 Imaging for Temporal Bone Surgery
Chapter 9 Conventional and Multiplanar High-Resolution Computed Tomography of the Temporal Bone
Chapter 10 Imaging for Tympanoplasty and Mastoidectomy
Chapter 11 Imaging for Stapes Surgery
Chapter 12 Rules and Hints
Part 5 Appendix
Chapter 13 Microsurgical Equipment
Chapter 1 Tympanoplasty
General Considerations
Definitions Tympanoplasty is the surgical reconstruction of the tympano-ossicular system and includes: can alplasty, meatoplasty, myringoplasty, and ossiculoplasty. Myringoplasty is a technique for reconstructing a vibrating tympanic membrane. Widening of the ex ternal auditory canal (canalplasty) is an integral part of myringoplasty. It should be carried out for the grafting of all anterior perforations of the tympanic membrane because it gives the necessary surgical access for their adequate repair. Canalplasty also facilitates healing, cleansing, and second-stage ossiculoplasty. Meatoplasty is used to enlarge the opening of the lateral (cartilaginous) external canal in proportion to the size of the medial (bony) canal. Different types of ossiculoplasty are necessary to restore the sound transmission from the drum to the inner ear. Aims of Tympanoplasty Eradication of disease. Restoration of tympanic aeration. Reconstruction of a sound-transformer mechanism. Creation of a dry, self-cleansing cavity. Preoperative Care Preoperative Investigations Tubal function. The function of the eustachian tube is assumed to be normal when the Valsalva or Toynbee maneuver is positive. Tympanometry is performed if the above-mentioned test results are negative. Knowledge of eustachian tube function is important for proper surgical planning and to assess the chance of a possible hearing improvement. Negative tubal tests, however, are not an absolute contraindication for tympanoplasty. Normal ventilation may indeed be restored in spite of a negative tubal test by surgical excision of scar tissue occluding the tympanic ostium of the eustachian tube. Good aeration of the opposite ear may serve as an indicator of good tubal function. Pneumatization of the temporal bone as viewed by conventional radiography or computed tomography (CT) scanning remains one of the best measures of evaluation of the ventilation of the middle ear cleft in early childhood. Temporary closure of perforation. Applying a disk of wet Gelfilm over the remaining drum permits temporary closure of a perforation. Resulting changes in hearing permit assessment of the condition of the ossicular chain and/or the oval and round windows. Fistula test. The fistula test should always be performed when a patient complains of vertigo or in the presence of a cholesteatoma. Be certain to maintain a good seal when performing the fistula test to avoid a caloric response to cold air. It is the unexpected fistula that leads to deafness at surgery. Therefore, be aware that a negative fistula test does not exclude the presence of a fistula. Rules for Preoperative Treatment The operating microscope, or equivalent magnification, and aspirating tubes are an essential prerequisite for proper preoperative evaluation and treatment. The aim is to operate, if possible, on a dry, well-ventilated ear. Clean the external canal using aspiration to remove fluid and 3% hydrogen peroxide (H2O2) to mollify dry secretion. Apply antibiotic ear drops or ointment on a strip of 0.5-cm ribbon gauze. The gauze should not be impregnated with too much ointment. The purpose of introducing gauze into the external auditory canal is: 1. To avoid free diffusion of ototoxic drugs into the middle ear, and; 2. to absorb secretion from the external canal. The strip of gauze should be changed frequently until it remains dry Avoid: 1. Systemic antibiotics, if there are no signs of general infection; 2. the use of free ear drops since in the presence of a perforated drum a sensorineural deafness may be induced (exception: ofloxacin ear drops). If the ear does not become dry after 3 to 4 weeks of treatment, surgery can be performed in spite of the draining ear. Antibiotic Treatment Dry ears. Routine perioperative i.v. antibiotic treatment (e.g., amoxicillin with clavulanic acid or ciprofloxacin) is given for myringoplasty, tympanoplasty with extensive bone work (mastoidectomy, epitympanectomy, posterior tympanotomy, modified radical operation, and reconstruction of an open cavity). No antibiotics are given routinely for reconstruction of the ossicular chain when the drum is intact (particularly in second-stage operations). Routine antibiotic treatment—amoxicillin and clavulanic acid—is given whenever the inner ear is exposed (stapedectomy, stapedotomy). Ciprofloxacin is preferred in revision surgery. Draining ears. If the preoperative treatment did not succeed in drying the ear, a bacteriologic investigation of the persisting secretion is performed only when the secretion is purulent. A predominantly clear mucous secretion is related to hyperplastic changes of the mucosa of the tympanic cavity and does not require bacteriologic investigation. Gramnegative microbes such as Pseudomonas pyocyanea and Proteus mirabilis, as well as fungi, are commonly found in most middle ear secretions because of a superinfection originating from the external canal. Ciprofloxacin is preferred in this situation. Preoperative Preparation The hair is shaved above and behind the ear (2 cm for tympanoplasty and mastoidectomy). No hair is removed for the endaural approach (stapedotomy, stapedectomy, or second-stage ossicular reconstruction). When a perforation is present, the canal is filled with sterile gauze during the surgical preparation to avoid injury to the middle ear by the disinfecting agent. The skin of the operating field and the pinna are cleaned with soap and water and a disinfection solution (povidone iodine). No effort is made to disinfect the external canal because we do not believe that sterilization is possible. Intraoperative Positioning of the Patient Local anesthesia. The correct position of the patient's head is important to insure comfortable access for the surgeon. The head should be slightly lower than the plane of the table. General anesthesia. The angle between the head and the shoulder should be between 100° and 130° to allow adequate working space for the surgeon's hands. In both local and general anesthesia, a slight Trendelenburg position is advantageous for visualization of the tympanic membrane. Postoperative Care The operating microscope, or equivalent magnification, aspirating tubes, speculum, and forceps are essential prerequisites for proper postoperative treatment. Myringoplasty, Tympanoplasty If packing remains dry: nothing for 8 to 10 days. If packing becomes wet: aspirate excess fluid from the packing for 6 to 8 days. The entire packing is removed under the microscope after 8 to 10 days. Gelfoam pledgets filling the canal are removed by gentle aspiration using the smallest possible suction tubes. Gelfoam pledgets over the fascia are left in place for another week. A strip of gauze slightly impregnated with antibiotic ointment (Terracortril, Pfizer International, New York) is placed in the lateral portion of the canal during this time. Later on, drying strips of gauze impregnated with antibiotic solution (hydrocortisone, neomycin, and polymyxin, such as Otosporin, Wellcome Foundation Ltd., London) are used. The external canal is covered with a piece of cotton, which is changed daily by the patient (see Fig. 81, p. 169). Transmastoid drain, see page 112. Open Cavity (Open Mastoido-epitympanectomy with Tympanoplasty [OMET]) Aspirate excess fluid from the packing for 6 to 8 days. Remove strips of gauze impregnated with ointment in steps at 2- to 3-day intervals. Begin to suction away Gelfoam filling the cavity after 2 to 3 weeks. Be aware that aspiration can induce vertigo due to the change in temperature. Use strips of gauze impregnated with ointment until granulation tissue has covered the bare bone. Drying gauze with antibiotic solution is used thereafter. Do not forget that in the presence of longstanding preoperative infections, an open cavity may need 1.5 to 2 months to epithelize completely. Do not forget that the postoperative treatment is as important as the operation itself. Anesthesia Local Anesthesia Indication Local anesthesia is used whenever no extensive bone work is needed in combination with an endaural approach (myringoplasty, second-stage ossicular chain reconstruction, stapes surgery). Premedication For adults of average weight (70 kg), 10 mg Valium (diazepam) or, if an anxiolytic is required, Dormicum (midazolam) i.v. 30 minutes before surgery. Injection 20 ml 1% lidocaine with 2 drops of 1: 1000 epinephrine (final concentration 1: 200 000 epinephrine). To reduce the burning sensation of the injection, 2 ml of 8.4% sodium-bicarbonate is mixed with 20 ml of lidocaine/epinephrine; 5–10 ml of this mixture is injected as demonstrated in Figure 1. The retroauricular infiltration of the soft tissues surrounding the auricle may induce a transient ipsilateral facial palsy. A study carried out by J. M. Lancer (Lancer and Fisch 1988) has shown that no adverse effects were observed either as a consequence of local anesthesia itself or of the transient facial weakness. Both the patient and the surgeon were happy...
