Effect Of Tympanoplasty With Soft-wall Reconstruction In The Treatment Of Cholesteatoma

Objective: To observe the therapeutic effect of canal wall down mastoidectomy with stageⅠtympanoplasty using postauricular myo-periosteal flap(PMPF)to reconstruct soft-wall of ear canal in the treatment of chronic otitis media with cholesteatoma.Methods: We observed the 60 patients(61 ears)who were treated with canal wall down mastoidectomy with tympanoplasty(CWD) by the soft-wall reconstruction of ear canal between Jan in 2005 and Sep in 2010 . All of the patients were definitely diagnosed the chronic otitis media with cholesteatoma by otology examination and temporal bone CT before surgery.The routine CWD was done firstly, which skeletonized the mastoid cavity, and did not reserve the posterior wall of the external auditory canal. The facial ridge was cut lowly after"breaking bridge", so that the pathological tissues especially in the sinus tympani and facial recess were cleaned up thoroughly. The stageⅠtympanoplasty was performed according to the situation in the surgery. The auricular bone prosthesis was made of the autogeneic cortical bone or residual incus. It was typeⅢa (raised typeⅢ) that the auricular bone prosthesis was placed on the head of the stapes if the stapes existed and moved better. It was typeⅢb (modified typeⅢ) that the auricular bone prosthesis was placed on the foot plate of the stapes if the stapes did not exist but the foot plate of the stapes moved better. The mastoid cortical bone lamellae were necessarily attached to the upside entry of the former tympanic sinus to increase the volume of the reconstructed tympanic cavity. The perforation of the tympanic membrane was mended by inlay or sandwich method using temporal fascia .The soft–wall reconstruction of the ear canal was performed by the method below.The method of the soft-wall reconstruction of the ear canal : The postauricular myo-periosteal flap(PMPF)with a prior pedicle was layed the back of the skin of the posterior canal wall , and was fixed by the absorbable Gelatin sponge in the mastoid cavity . The normal intact ring-shaped skin of the external auditory canal was reserved. The cavityplasty of auricular concha (CAC) was not performed. The reconstructed external auditory canal was nearly as the same shape as the normal. The remainder of the mastoid cavity was obliterated with the absorbable Gelatin sponge. The external auditory canal was stuffed by the iodoform gauzes, and a draining pipe was set in the mastoid cavity. The incision was sutured routinely, and pressure dressing was indispensable.35 ears were treated by typeⅢa and 26 ears by typeⅢb in our group. All the patients had been given intravenousdrip antibiotic for 7~10 days to prevent from infection. When to draw out the draining pipe was dominated by the draining quantity in the mastoid cavity. The stitchs were removed from the incision after surgery 8~9 days. The iodoform gauzes were drawn out from the external auditory canal after surgery 12 days. Henceforth the external auditory canal was wadded by the gauzes with 0.3% ofloxacin Ear Drops (Tarivid) and budesonide (Pulmicort), which were replaced once time a day or every other day till the dry ear formed when the exudation stopped. We observed the dry ear time and studied the postoperative modality and function of the external auditory canal and the postoperative complications. The postoperative hearing was examined after surgery 3 months. The last hearing result was analyzed by statistics. The parameters were compared using t-test.Results:The patients were followed up between 6 months and 24 months after surgery. 19 ears had been followed up by 6~11 months, 15 ears by 12~ 17 months and 27 ears by 18~24 months.1.The dry ear time:The dry ear standard was that the exudation ceased completely. The dry ear time was counted from the first day after the surgery. The dry ear time was 15~ 29 days in our group. The mean dry ear time was 21.4±2.6 days.2.The modality and function of the external auditory canal:The posterior meatal wall was soft in a sort of way initially, but it became harder and harder after dry ear. The modality of the external auditory canal was normal on the whole. It was appreciably broad near the epitympanic recess, but it did not affect the aesthetic concerns. There were no crust and secretion in it for it had the function of self-cleanness, and obtained efficient aeration and drainage.3.The postoperative hearing:The postoperative average air conduction threshold was 39.6±8.2 dBHL, which was lower than the preoperative 53.8±6.8 dBHL in our group. The difference was statistically significant by paired t-test ( t= 18.5, P<0.05 ) . The postoperative average air-bone gap was 26.0±6.8 dBHL, which was lower than the preoperative 40.6±5.6 dBHL. The difference was statistically significant ( t= 17.0,P<0.05 ) when they were compared by paired t-test . It showed that the postoperative hearing was better than the preoperative in our group.The postoperative hearing was improved by more than 20 dB (average air conduction threshold ) in 18 ears (29.5%) , by 15~19 dB in 13 ears (21.3% ),by 10~14 dB in 17 ears ( 27.9% ) and by less than 10 dB in 13 ears ( 21.3% ) who had no hearing gain .The surgeries in 48 ears were effective , and the effective power was 78.7 % (48/61) when the criterion was that the postoperative average air-bone gap decreased more than 10 dB .The postoperative average air-bone gap that showed the hearing improvement degree was respectively 24.0±6.0 dBHL in typeⅢa and 30.2±6.3 dBHL in typeⅢb. The preoperative average air-bone gap was respectively 40.8±5.7dBHL in the typeⅢa and 40.3±5.6 dBHL in the typeⅢb. It was statistically significant (t= 3.91 , P<0.05) when the postoperative average air-bone gap was compared by the two sample t-test in the two types . Therefore it showed that the postoperative hearing in typeⅢa was better than that in the typeⅢb in our group.4. The necrosis and atrophy of the postauricular myo-periosteal flap(PMPF) did not appeared , and it did not retract . There were no the paralysis of the facial nerve and no labyrinthitis, and no other encephalic and extracranial complications. The recurrence of the cholesteatoma did not happen. A few complications included hydrops in the mastoid cavity , shift of the postauricular myo-periosteal flap(PMPF), the recrudescent perforation of the tympanic membrane and hearing decrease and so on . But the majority of them were not particular including the hydrops in the mastoid cavity, recrudescent perforation of the tympanic membrane and hearing decrease. Conclusions:1. CWD using the postauricular myo-periosteal flap(PMPF) to reconstruct soft-wall of ear canal can recover the modality and function of the external auditory canal on the whole , and the cavityplasty of auricular concha (CAC) is not needed .The postoperative hearing can be improved by this technique satisfactorily .2. The pathologic tissues can be wiped off thoroughly, so the recurrence of cholesteatoma decreases by this technique. The dry ear appears quickly, and the crust can avoid.3. The postauricular myo-periosteal flap(PMPF) that does not create rejection is obtained conveniently , and the necrosis can not happen easily. The reconstructed soft-wall of ear canal is not soft. It has application value because it is economical to use it and can help to alleviate the patient ,s economy burden.The conventional CWD has the fault of slow dry ear and the crust depositing, it is settled by the obliteration of the mastoid cavity and the cavityplasty of auricular concha (CAC). But it increases the trauma and the infection risk. The aesthetic appearance can be affected if the cavity of auricular concha is large too much. And the symptom of tinnitus and vertigo can appear when the ear meets the stimulus. We think that the modality and function of the external auditory canal is uniform. The normal modality of the external auditory canal is the foundation of its normal function that it can increase the sound wave pressure and safeguard middle ear. Our research emphasizes that the reservation of the modality and function of the external auditory canal is very important. It accords with the faith of micro-trauma surgery and the orientation of functional surgery. Our research has indicated that it is feasible to reconstruct the external auditory canal to reserve the normal function.