- Email: [email protected]
Mechanical small fenestra stapedotomy
MECHANICAL SMALL FENESTRA STAPEDOTOMY ANTONIO DE LA CRUZ, MD, SUJANA S. CHANDRASEKHAR, MD
This article reviews mechanical small fenestra stepedotomy for the surgical treatment of otosclerosis.
Otosclerosis is the disease classically described as one in which "the patient hears nothing, and the physician sees nothing." Surgery for this disorder began with stapes mobilization in the latter part of the 19th century, with one investigator reporting total stapedectomy. 1 Although initial hearing results were good, there was an unacceptable rate of inner ear damage and infection, and the procedures were abandoned. Surgical interest in this condition was reawakened in 1923 when Holmgren described the fenestration operation.-" This procedure was refined into a one-stage procedure by Lempert in 1938, who is acknowledged as the father of otosclerosis surgery. 3 In 1952, Rosen reintroduced stapes mobilization, however, refixation was a common problem. 4 Shea made a tremendous contribution when he moved otosclerosis surgery forward to the next step by introducing total stapedectomy with vein graft coverage of the oval window and use of a Teflon incus to footplate prosthesis. 5 This procedure replaced all prior ones. The next step was the development of the small fenestra stapedotomy, which was championed by European otologists in the 1970s, and quickly popularized by most otologists. In 1978, Perkins introduced the laser stapedotomy, which is a less traumatic technique for both initial and revision stapes surgery. 6 This is the technique employed preferentially by the senior author.
PATIENT SELECTION AND PREOPERATIVE EVALUATION Stapedectomy should be considered in the patient with probable otosclerosis whose air-bone gap is greater than 25 dB. This audiologic finding is confirmed by the surgeon using the 512- and 1,024-Hz tuning forks, which should reverse preoperatively. The option of using hearing aid(s) should be discussed thoroughly with the patient. A patient with a mixed hearing loss will be able to use a much less powerful hearing aid after correction of the air-bone gap. Although a positive family history is significant, one must From the University of Southern California, School of Medicine, Los Angeles, CA, and Otology/Neurotology, Section of Otolaryngology-Head and Neck Surgery, University of Medicine and Dentistry of NJ--New Jersey Medical School, Newark, NJ. Address reprint requests to Antonio De la Cruz, MD, Director of Education, House Ear Institute, 2100 W Third St, Los Angeles, CA 90057. Copyright © 1998 by W.B. Saunders Company 1043-1810/98/0901-0006508.00/0
keep in mind that there is no family history of hearing loss in approximately 50% of patients. Patients with infectious middle ear disease or chronic otitis media with perforation should not undergo stapedectomy until the perforation has been closed nor should individuals with active upper respiratory infection at the time of surgery. In general, it is prudent to wait until teenage or older years before performing this surgery, owing to better patient cooperation, although there is no increased risk of sensorineural hearing loss or refixation in younger individuals. There is no upper age limit, except that mediated by medical infirmity. Congenital stapes fixation should be considered in the patient who claims hearing loss in that ear since birth, because it may be associated with a perilymph gusher, and the surgeon must be prepared. In patients with a history suggestive of endolymphatic hydrops, it is prudent to treat the vertiginous disorder with diuretics until the patient has no symptoms of aural fullness, fluctuating hearing loss, roaring tinnitus, or episodic vertigo. Stapes surgery in the symptomatic patient can result in rupture of a dilated saccular membrane, with resultant severe vertigo and sensorineural hearing loss (SNHL). Any chronic external auditory canal problem is addressed thoroughly before surgery. It is exceptionally rare that an ear canal is too narrow for the experienced stapes surgeon; in a survey, otologists reported having had to use the endaural or postauricular approach in one in 300 cases. The longer the duration of otosclerosis, the greater the incidence of obliterative otosclerosis. Stapes gusher is suspected when the hearing loss is mixed, and high-resolution computerized tomography of the inner ear and temporal bone should be performed preoperatively. The patient with otosclerosis usually gives a history of hearing difficult for a long time, and often the patient seeks attention because he or she is unable to continue compensating for the hearing loss adequately. There is no history of infection or trauma. Family history is positive in 50%. The audiogram must show at least a 25 dB air-bone gap in order to offer surgical intervention. This is confirmed with tuning forks. The senior author does not use tympanometry or acoustic reflexes routinely; when used, the tympanogram should be normal or show a shallow "A" pattern, and the acoustic reflexes are absent or can show an "on-off" pattern even in very early otosclerosis. The patient must be adequately counseled and prepared. The risk of total SNHL following surgery is quoted as 1%, although it is not that high in our experience. The risk of no
OPERATIVE TECHNIQUES IN OTOLARYNGOLOGY--HEAD AND NECK SURGERY, VOL 9, NO 1 (MAR), 1998: PP 33-37
33
real improvement or some SNHL is quoted at about 3% to 4%. The chance of closure of the air-bone gap within 10 dB is 95%. We prefer local anesthesia with sedation and the patient must be psychologically prepared to cooperate. When general anesthesia is used, it is important to communicate concerns regarding bucking and coughing with the anesthesiologist. Patients who use their sense of taste in their work should be counseled against stapes surger~ because taste may be altered even with simple exposure of the chorda tympani nerve.
OPERATIVE TECHNIQUE The patient is given a sedative 90 minutes before surgery that is supplemented intraoperatively with intravenous midazolam (Versed) or diazepam (Valium). Local anesthesia is preferred for the benefits of decreased bleeding and the added safety of immediate awareness of vertigo. The otologic position (Fig 1) has the patient lying supine with head turned away from the affected ear. The head lies on a donut headrest, with the opposite ear in the hole. The table is turned so that the surgeon's legs and the microscope base can fit comfortable underneath it. The nurse is across from the surgeon, and the anesthesiologist and monitoring equipment (eg, blood pressure, pulse oximeter, EKG) are at the patient's feet. Strict sterile technique is important, because infection can have catastrophic complications. The ear canal is irrigated with povidone-iodine solution, which is then washed out with saline. Local injection of 2% lidocaine with 1:40,000 units of epinephrine is administered via a 30-gauge needle into four quadrants of the ear canal to a total amount of 2 mL (Fig 2). The anesthesia is milked down into the deep ear canal using the speculum. Adequate injection has been performed when the canal wall blanches. The second author (SSC) uses Emla cream (lidocaine 2.5% and prilocaine 2.5%) placed into the ear canal in the preoperative holding area, using a small syringe, filled with I mL of the cream, and introduced via angiocath. This allows for increased comfort with injection of the local anesthesia after the cream is suctioned out. The largest possible speculum is introduced into the osseous portion of the external auditory canal. The authors do not use a speculum holder, although many others do. The canal incision may be either triangular or square-shaped; in either case, the flap should be about 6 mm long and there
~
should be slightly more skin length superiorly, because this is where the bone removal takes place (Fig 3). The incision is made with a disposable blade, and the skin is elevated with a round knife. The fibrous annulus is clearly identified (this is commonly a site of tympanic membrane perforation). At the level of the annulus, a Rosen needle is used to enter the middle ear space under the annulus, inferiorly. An annulus elevator is used to elevate the annulus from inferiorly to superiorly. Care is taken not to tear the tympanic membrane. Although very small tears can be patched with continuation of the surgery, if a large hole is made in the tympanic membrane, this should be repaired and the stapes surgery should be abandoned until the tympanic membrane has healed. The double-ended stapes curette or the stapedotomy drill is used to remove bone from the superior portion of the posterior wall of the external ear canal. This is done in such a fashion that the curved area becomes square (Fig 4),
Back
~4~/// j;// Table Nurse-
FIGURE 2. Lidocaine 2% with 1:40,000 units epinephrine is injected into the four quadrants of the ear canal.
Mayo
~
s
~
~Stand
,no.,h.,o; FIGURE 1. Arrangement of the operating room for stapes surgery.
34
FIGURE 3. Outline of the rectangular tympanotomy flap.
DE LACRUZ AND CHANDRASEKHAR
FIGURE 6. The stapedius tendon is cut using small microscissors.
FIGURE 4. Area of bone removal from the posterior bony canal.
so that the entire footplate and the facial canal can be observed. The chorda tympani nerve is identified and gently lifted out of the w a y inferiorly. Care is taken not to stretch the nerve. In the u n c o m m o n event that the nerve cannot be mobilized satisfactorily without stretching, it is better to section it cleanly. A small round right-angled knife (the "incudostapedial joint knife") is used to separate the incudostapedial joint from posterior to anterior without lifting the incus (Fig 5). The knife is introduced at an angle from the surgeon's site of vision, to allow full visualization of the procedure. Before the instrument is withdrawn, it is placed under the long process of the malleus to check for fixation; this occurs in 1:200 cases and must be recognized and addressed. The stapes tendon is cut with microscissors (Fig 6). The authors do not preserve or reattach the tendon. The crura are fractured d o w n w a r d away from the facial nerve using a Rosen needle (Fig 7). A small hole ~icked into the middle
of the footplate before downfracture will prevent a s u d d e n decompression of the vestibule with inadvertent stapes footplate mobilization. The distance from the footplate to the lateral surface of the incus is measured using calibrated measuring devices of k n o w n length (Fig 8), and 0.25 m m is added to this measurement. The surgeon m u s t be familiar with the prosthesis to be used to k n o w whether to measure to the medial or lateral surface of the incus. The stapedotomy is created with a 0.7-ram d i a m o n d bur in an electric microdrill. The bur is centered at the union of the middle and posterior third of the footplate (this is the point farthest from the saccule and utricle) and a very small a m o u n t of pressure is exerted during drilling (Fig 9). Care is taken not to suction perilymph after the stap e d o t o m y has been made. The 0.6-ram diameter prosthesis is inserted into the stapedotomy and hooked onto the incus (Fig 10). A crimper is used to close the loop on the incus, and the prosthesis is moved gently to ensure that it is not too tight or too loose. Gentle inward pressure on the prosthesis will ensure that it is not too long if the patient does not experience vertigo with the maneuver.
/
J °
j
FIGURE 5. The incudostapedial joint is separated with a round joint knife.
MECHANICAL SMALL FENESTRA STAPEDOTOMY
/f
J
,/
FIGURE 7. After a small hole has been created in the footplate, the crura are fractured downward away from the facial nerve.
35
FIGURE 8. The distance from the lateral surface of the incus to the footplate is measured.
The prosthesis preferred by the authors is the De la Cruz fluoroplast platinum piston. The fluoroplast portion is only 1.25 m m long, and so if any of the white is visible above the fenestra opening, the prosthesis cannot be too long. Once the prosthesis is in place, an attempt is made to displace it with a right angle hook. If the prosthesis cannot be displaced, it cannot be too short, either. This resolves the foremost reason for revision stapes surgery. Autologous blood from the arm is used to seal the oval window. The tympanomeatal flap is placed back into position. At this juncture, the patient can be asked to repeat whispered spondee words. This is generally very gratifying for both the patient and the physician, but the patient must be cautioned that the hearing will become worse, due to fluid
FIGURE 10. The 0.6-mm De la Cruz fluoroplast platinum prosthesis in the fenestra is sealed with autologous blood.
and edema in the middle ear, and packing in the ear canal, before it becomes good again. The ear canal is packed with Kof-House ointment, which will dissolve on its own. A cottonball is the only dressing that is required. POSTOPERATIVE
CARE
This is an outpatient procedure, and the patient is discharged 3 to 4 hours after surgery. If the patient experiences significant vertigo, h e / s h e may be observed and treated supportively overnight. The patient is given an instruction sheet stating that they should avoid sneezing, nose blowing, straining, and heavy lifting for about 2 to 3 weeks. The ear canal should be kept dry until after the first postoperative visit, which is in about 1 week. This is to ensure that the flap is healing nicely. Patients are allowed to travel by air after 4 days. The only permanent restriction is for scuba diving, although there is some discussion in the otologic community over this issue. Amoxicillin (or erythromycin for penicillin-allergic patients) is given by mouth for 5 days. Some vertigo may be experienced over the first 2 to 3 days; this is treated symptomatically. The first postoperative audiogram is obtained at 3 weeks, and then at 4 months. In cases of bilateral otosclerosis, 6 months of stable hearing in the first ear after surgery is required before operating on the second ear. Early re-exploration is indicated for severe, incapacitating vertigo after surgery. This should not occur if the operation has been done under local anesthesia when the patient can indicate vertigo from a too-long prosthesis. Late re-exploration may be indicated for persistent large air-bone gap (prosthesis too short), or vertigo with changes in pressure (prosthesis too long). Re-exploration has higher risks of SNHL and vertigo, and should be done under local anesthesia. CONCLUSIONS
FIGURE 9. The microdrill with a 0.7-mm diamond bur is used to create the fenestra at junction of the middle and posterior third of the footplate.
36
We have presented our technique for use of the microdrill to perform small fenestra stapedotomy. Until the introduction of newer otologic lasers, the senior author used
DE LA CRUZ AND CHANDRASEKHAR
m e c h a n i c a l s m a l l f e n e s t r a s t a p e d o t o m y for t h e t r e a t m e n t of s t a p e d i a l o t o s c l e r o s i s . A l t h o u g h w e p r e f e r to u s e a n o t o l o g i c l a s e r for t r e a t m e n t of o t o s c l e r o t i c s t a p e s fixation, m e c h a n i c a l s m a l l f e n e s t r a s t a p e d o t o m y is still p r e f e r r e d to total stapedectomy.
REFERENCES 1. Jack FL: Remarkable improvement of the hearing by removal of the stapes. Trans Am Otol Soc 284:474-489, 1893
MECHANICAL SMALL FENESTRA STAPEDOTOMY
2. Holmgren G: Some experiences in surgery of otosclerosis. Acta Otolaryngol (Stockh) 5:460, 1923 3. Lempert J: Improvement in hearing in cases of otosclerosis: A new, one stage surgical technic. Arch Otolaryngol Head Neck Surg 28:42, 1938 4. Rosen S: Restoration of hearing in otosclerosis by mobilization of the fixed stapedial footplate, an analysis of results. Laryngoscope 65:224269, 1955 5. Shea JJ Jr: Fenestration of the oval window. Ann Otol Rhinol Laryngol 67:932-951, 1958 6. Perkins RC: Laser stapedotomy for otosclerosis. Laryngoscope 91:228241, 1980
37
This article reviews mechanical small fenestra stepedotomy for the surgical treatment of otosclerosis.
Otosclerosis is the disease classically described as one in which "the patient hears nothing, and the physician sees nothing." Surgery for this disorder began with stapes mobilization in the latter part of the 19th century, with one investigator reporting total stapedectomy. 1 Although initial hearing results were good, there was an unacceptable rate of inner ear damage and infection, and the procedures were abandoned. Surgical interest in this condition was reawakened in 1923 when Holmgren described the fenestration operation.-" This procedure was refined into a one-stage procedure by Lempert in 1938, who is acknowledged as the father of otosclerosis surgery. 3 In 1952, Rosen reintroduced stapes mobilization, however, refixation was a common problem. 4 Shea made a tremendous contribution when he moved otosclerosis surgery forward to the next step by introducing total stapedectomy with vein graft coverage of the oval window and use of a Teflon incus to footplate prosthesis. 5 This procedure replaced all prior ones. The next step was the development of the small fenestra stapedotomy, which was championed by European otologists in the 1970s, and quickly popularized by most otologists. In 1978, Perkins introduced the laser stapedotomy, which is a less traumatic technique for both initial and revision stapes surgery. 6 This is the technique employed preferentially by the senior author.
PATIENT SELECTION AND PREOPERATIVE EVALUATION Stapedectomy should be considered in the patient with probable otosclerosis whose air-bone gap is greater than 25 dB. This audiologic finding is confirmed by the surgeon using the 512- and 1,024-Hz tuning forks, which should reverse preoperatively. The option of using hearing aid(s) should be discussed thoroughly with the patient. A patient with a mixed hearing loss will be able to use a much less powerful hearing aid after correction of the air-bone gap. Although a positive family history is significant, one must From the University of Southern California, School of Medicine, Los Angeles, CA, and Otology/Neurotology, Section of Otolaryngology-Head and Neck Surgery, University of Medicine and Dentistry of NJ--New Jersey Medical School, Newark, NJ. Address reprint requests to Antonio De la Cruz, MD, Director of Education, House Ear Institute, 2100 W Third St, Los Angeles, CA 90057. Copyright © 1998 by W.B. Saunders Company 1043-1810/98/0901-0006508.00/0
keep in mind that there is no family history of hearing loss in approximately 50% of patients. Patients with infectious middle ear disease or chronic otitis media with perforation should not undergo stapedectomy until the perforation has been closed nor should individuals with active upper respiratory infection at the time of surgery. In general, it is prudent to wait until teenage or older years before performing this surgery, owing to better patient cooperation, although there is no increased risk of sensorineural hearing loss or refixation in younger individuals. There is no upper age limit, except that mediated by medical infirmity. Congenital stapes fixation should be considered in the patient who claims hearing loss in that ear since birth, because it may be associated with a perilymph gusher, and the surgeon must be prepared. In patients with a history suggestive of endolymphatic hydrops, it is prudent to treat the vertiginous disorder with diuretics until the patient has no symptoms of aural fullness, fluctuating hearing loss, roaring tinnitus, or episodic vertigo. Stapes surgery in the symptomatic patient can result in rupture of a dilated saccular membrane, with resultant severe vertigo and sensorineural hearing loss (SNHL). Any chronic external auditory canal problem is addressed thoroughly before surgery. It is exceptionally rare that an ear canal is too narrow for the experienced stapes surgeon; in a survey, otologists reported having had to use the endaural or postauricular approach in one in 300 cases. The longer the duration of otosclerosis, the greater the incidence of obliterative otosclerosis. Stapes gusher is suspected when the hearing loss is mixed, and high-resolution computerized tomography of the inner ear and temporal bone should be performed preoperatively. The patient with otosclerosis usually gives a history of hearing difficult for a long time, and often the patient seeks attention because he or she is unable to continue compensating for the hearing loss adequately. There is no history of infection or trauma. Family history is positive in 50%. The audiogram must show at least a 25 dB air-bone gap in order to offer surgical intervention. This is confirmed with tuning forks. The senior author does not use tympanometry or acoustic reflexes routinely; when used, the tympanogram should be normal or show a shallow "A" pattern, and the acoustic reflexes are absent or can show an "on-off" pattern even in very early otosclerosis. The patient must be adequately counseled and prepared. The risk of total SNHL following surgery is quoted as 1%, although it is not that high in our experience. The risk of no
OPERATIVE TECHNIQUES IN OTOLARYNGOLOGY--HEAD AND NECK SURGERY, VOL 9, NO 1 (MAR), 1998: PP 33-37
33
real improvement or some SNHL is quoted at about 3% to 4%. The chance of closure of the air-bone gap within 10 dB is 95%. We prefer local anesthesia with sedation and the patient must be psychologically prepared to cooperate. When general anesthesia is used, it is important to communicate concerns regarding bucking and coughing with the anesthesiologist. Patients who use their sense of taste in their work should be counseled against stapes surger~ because taste may be altered even with simple exposure of the chorda tympani nerve.
OPERATIVE TECHNIQUE The patient is given a sedative 90 minutes before surgery that is supplemented intraoperatively with intravenous midazolam (Versed) or diazepam (Valium). Local anesthesia is preferred for the benefits of decreased bleeding and the added safety of immediate awareness of vertigo. The otologic position (Fig 1) has the patient lying supine with head turned away from the affected ear. The head lies on a donut headrest, with the opposite ear in the hole. The table is turned so that the surgeon's legs and the microscope base can fit comfortable underneath it. The nurse is across from the surgeon, and the anesthesiologist and monitoring equipment (eg, blood pressure, pulse oximeter, EKG) are at the patient's feet. Strict sterile technique is important, because infection can have catastrophic complications. The ear canal is irrigated with povidone-iodine solution, which is then washed out with saline. Local injection of 2% lidocaine with 1:40,000 units of epinephrine is administered via a 30-gauge needle into four quadrants of the ear canal to a total amount of 2 mL (Fig 2). The anesthesia is milked down into the deep ear canal using the speculum. Adequate injection has been performed when the canal wall blanches. The second author (SSC) uses Emla cream (lidocaine 2.5% and prilocaine 2.5%) placed into the ear canal in the preoperative holding area, using a small syringe, filled with I mL of the cream, and introduced via angiocath. This allows for increased comfort with injection of the local anesthesia after the cream is suctioned out. The largest possible speculum is introduced into the osseous portion of the external auditory canal. The authors do not use a speculum holder, although many others do. The canal incision may be either triangular or square-shaped; in either case, the flap should be about 6 mm long and there
~
should be slightly more skin length superiorly, because this is where the bone removal takes place (Fig 3). The incision is made with a disposable blade, and the skin is elevated with a round knife. The fibrous annulus is clearly identified (this is commonly a site of tympanic membrane perforation). At the level of the annulus, a Rosen needle is used to enter the middle ear space under the annulus, inferiorly. An annulus elevator is used to elevate the annulus from inferiorly to superiorly. Care is taken not to tear the tympanic membrane. Although very small tears can be patched with continuation of the surgery, if a large hole is made in the tympanic membrane, this should be repaired and the stapes surgery should be abandoned until the tympanic membrane has healed. The double-ended stapes curette or the stapedotomy drill is used to remove bone from the superior portion of the posterior wall of the external ear canal. This is done in such a fashion that the curved area becomes square (Fig 4),
Back
~4~/// j;// Table Nurse-
FIGURE 2. Lidocaine 2% with 1:40,000 units epinephrine is injected into the four quadrants of the ear canal.
Mayo
~
s
~
~Stand
,no.,h.,o; FIGURE 1. Arrangement of the operating room for stapes surgery.
34
FIGURE 3. Outline of the rectangular tympanotomy flap.
DE LACRUZ AND CHANDRASEKHAR
FIGURE 6. The stapedius tendon is cut using small microscissors.
FIGURE 4. Area of bone removal from the posterior bony canal.
so that the entire footplate and the facial canal can be observed. The chorda tympani nerve is identified and gently lifted out of the w a y inferiorly. Care is taken not to stretch the nerve. In the u n c o m m o n event that the nerve cannot be mobilized satisfactorily without stretching, it is better to section it cleanly. A small round right-angled knife (the "incudostapedial joint knife") is used to separate the incudostapedial joint from posterior to anterior without lifting the incus (Fig 5). The knife is introduced at an angle from the surgeon's site of vision, to allow full visualization of the procedure. Before the instrument is withdrawn, it is placed under the long process of the malleus to check for fixation; this occurs in 1:200 cases and must be recognized and addressed. The stapes tendon is cut with microscissors (Fig 6). The authors do not preserve or reattach the tendon. The crura are fractured d o w n w a r d away from the facial nerve using a Rosen needle (Fig 7). A small hole ~icked into the middle
of the footplate before downfracture will prevent a s u d d e n decompression of the vestibule with inadvertent stapes footplate mobilization. The distance from the footplate to the lateral surface of the incus is measured using calibrated measuring devices of k n o w n length (Fig 8), and 0.25 m m is added to this measurement. The surgeon m u s t be familiar with the prosthesis to be used to k n o w whether to measure to the medial or lateral surface of the incus. The stapedotomy is created with a 0.7-ram d i a m o n d bur in an electric microdrill. The bur is centered at the union of the middle and posterior third of the footplate (this is the point farthest from the saccule and utricle) and a very small a m o u n t of pressure is exerted during drilling (Fig 9). Care is taken not to suction perilymph after the stap e d o t o m y has been made. The 0.6-ram diameter prosthesis is inserted into the stapedotomy and hooked onto the incus (Fig 10). A crimper is used to close the loop on the incus, and the prosthesis is moved gently to ensure that it is not too tight or too loose. Gentle inward pressure on the prosthesis will ensure that it is not too long if the patient does not experience vertigo with the maneuver.
/
J °
j
FIGURE 5. The incudostapedial joint is separated with a round joint knife.
MECHANICAL SMALL FENESTRA STAPEDOTOMY
/f
J
,/
FIGURE 7. After a small hole has been created in the footplate, the crura are fractured downward away from the facial nerve.
35
FIGURE 8. The distance from the lateral surface of the incus to the footplate is measured.
The prosthesis preferred by the authors is the De la Cruz fluoroplast platinum piston. The fluoroplast portion is only 1.25 m m long, and so if any of the white is visible above the fenestra opening, the prosthesis cannot be too long. Once the prosthesis is in place, an attempt is made to displace it with a right angle hook. If the prosthesis cannot be displaced, it cannot be too short, either. This resolves the foremost reason for revision stapes surgery. Autologous blood from the arm is used to seal the oval window. The tympanomeatal flap is placed back into position. At this juncture, the patient can be asked to repeat whispered spondee words. This is generally very gratifying for both the patient and the physician, but the patient must be cautioned that the hearing will become worse, due to fluid
FIGURE 10. The 0.6-mm De la Cruz fluoroplast platinum prosthesis in the fenestra is sealed with autologous blood.
and edema in the middle ear, and packing in the ear canal, before it becomes good again. The ear canal is packed with Kof-House ointment, which will dissolve on its own. A cottonball is the only dressing that is required. POSTOPERATIVE
CARE
This is an outpatient procedure, and the patient is discharged 3 to 4 hours after surgery. If the patient experiences significant vertigo, h e / s h e may be observed and treated supportively overnight. The patient is given an instruction sheet stating that they should avoid sneezing, nose blowing, straining, and heavy lifting for about 2 to 3 weeks. The ear canal should be kept dry until after the first postoperative visit, which is in about 1 week. This is to ensure that the flap is healing nicely. Patients are allowed to travel by air after 4 days. The only permanent restriction is for scuba diving, although there is some discussion in the otologic community over this issue. Amoxicillin (or erythromycin for penicillin-allergic patients) is given by mouth for 5 days. Some vertigo may be experienced over the first 2 to 3 days; this is treated symptomatically. The first postoperative audiogram is obtained at 3 weeks, and then at 4 months. In cases of bilateral otosclerosis, 6 months of stable hearing in the first ear after surgery is required before operating on the second ear. Early re-exploration is indicated for severe, incapacitating vertigo after surgery. This should not occur if the operation has been done under local anesthesia when the patient can indicate vertigo from a too-long prosthesis. Late re-exploration may be indicated for persistent large air-bone gap (prosthesis too short), or vertigo with changes in pressure (prosthesis too long). Re-exploration has higher risks of SNHL and vertigo, and should be done under local anesthesia. CONCLUSIONS
FIGURE 9. The microdrill with a 0.7-mm diamond bur is used to create the fenestra at junction of the middle and posterior third of the footplate.
36
We have presented our technique for use of the microdrill to perform small fenestra stapedotomy. Until the introduction of newer otologic lasers, the senior author used
DE LA CRUZ AND CHANDRASEKHAR
m e c h a n i c a l s m a l l f e n e s t r a s t a p e d o t o m y for t h e t r e a t m e n t of s t a p e d i a l o t o s c l e r o s i s . A l t h o u g h w e p r e f e r to u s e a n o t o l o g i c l a s e r for t r e a t m e n t of o t o s c l e r o t i c s t a p e s fixation, m e c h a n i c a l s m a l l f e n e s t r a s t a p e d o t o m y is still p r e f e r r e d to total stapedectomy.
REFERENCES 1. Jack FL: Remarkable improvement of the hearing by removal of the stapes. Trans Am Otol Soc 284:474-489, 1893
MECHANICAL SMALL FENESTRA STAPEDOTOMY
2. Holmgren G: Some experiences in surgery of otosclerosis. Acta Otolaryngol (Stockh) 5:460, 1923 3. Lempert J: Improvement in hearing in cases of otosclerosis: A new, one stage surgical technic. Arch Otolaryngol Head Neck Surg 28:42, 1938 4. Rosen S: Restoration of hearing in otosclerosis by mobilization of the fixed stapedial footplate, an analysis of results. Laryngoscope 65:224269, 1955 5. Shea JJ Jr: Fenestration of the oval window. Ann Otol Rhinol Laryngol 67:932-951, 1958 6. Perkins RC: Laser stapedotomy for otosclerosis. Laryngoscope 91:228241, 1980
37