Post operative hearing status in canal wall down mastoidectomy with type III tympanoaplasty

Background: Canal wall down procedure may be with or without reconstruction such as tympanic membrane, ossicular chain or posterior canal wall reconstruction. To preserve and improvement of hearing, prevent discharge and recurrence, now a days canal wall down mastoidectomy with reconstruction such as type III tympanoplasty under magnification is a modern advancement in otology Objectives: To find out hearing status before mastoidectomy and hearing status after canal wall down mastoidectomy with and without reconstruction. Methods: Prospectove study done on 3 tertiaty hospitals in Dhaka. Number of patients were 40 who underwent for modified radical mstoidectomy, 20 were with reconstruction and 20 without reconstruction (Type 3 Tympanoplasty) Results: hearing was deteriorated in most of the cases (60%) of MRM without tympanoplasty. Air Bone (AB) Gap Increased 3.65dB after CWD without reconstruction. Closer of AB gap (9.77 dB) occurred after CWD with reconstruction. 1. Assistant Professor of ENT, Pabna Medical College 2. Associate Professor of ENT, Pabna Medical College 3. Assistant Professor of ENT, Pabna Medical College 4. Associate Professor of ENT, Popular Medical College, Dhaka 5. Professor of ENT, Ibrahim Medical College, Dhaka Address of Correspondence: Dr. Sheikh Mohammad Rafiqul Hossain, Assistant Professor of ENT, Pabna Medical College. Introduction: Atticoantral variety of CSOM most commonly involves the epitympanum & usually associated with cholesteatoma. Cholesteatoma is histologically benign but may be aggressive locally and associated with significant morbidity or mortality if untreated. The choice of treatment of cholesteatoma is surgery for which the goal is total clearance of disease, to obtain a safe, dry ear, restoration or maintaining the functional capacity if possible. There are different surgical modalities of treatment according to the extent of cholesteatoma and amount of destruction such as suction clearance, intact canal wall procedures (cortical mastoidectomy, combined approach tympanoplasty) and canal wall down procedures (atticotomy, atticotoantrostomy, Modified radical mastoidectomy and Radical mastoidectomy) In the early days of chronic ear surgery radical mastoidectomy was the operation of choice but poor hearing and high incidence of chronic or intermittent discharge were the limitations of this procedure. To overcome this disadvantage modified radical mastoidectomy was proposed and most commonly performed. 4,2 In intact canal wall procedure there is good preservation of hearing but more chance of incomplete clearance or recurrence of disease. Canal wall down procedure causes disease clearance properly but the disadvantage of poor preservation of hearing which can be overcome by reconstructive surgery. 1,4 The techniques and concepts of modern reconstructive middle ear surgery came into the field when Moritz (1952), Zollner (1953, 1955), Wullstein (1953, 1956) in Germany introduced tympanoplasty operation 2 Canal wall down procedure may be with or without reconstruction such as tympanic membrane, ossicular chain or posterior canal wall reconstruction. To preserve and improvement of hearing, prevent discharge and recurrence, now a days canal wall down mastoidectomy with reconstruction such as type III tympanoplasty under magnification is a modern advancement in otology. 2,3 In most of the patients of chronic suppurative otitis media, Pure Tone Audiometry shows the hearing loss ranges from mild to severe depending on extent of the disease. In canal wall down mastoidectomy without reconstruction there is destruction of ossicles and/or Tympanic membrane for complete clearance of disease. The postoperative audiometric evaluation shows further hearing loss. On the other hand canal wall down mastoidectomy with reconstruction i.e. tympanoplasty, ossiculoplasty improves hearing in variable amount. In the study of MU Ahmed (2005) and Ajalloueyan (2006) shows that significant number of patients receiving such procedure have improved their hearing status. Careful follow up, by clinical, radiological and audiometric means are essential to make a comment about hearing status of the patient. The worldwide practice of performing such surgery and it’s good outcome has encouraged to do this research work. Modified radical mastoidectomy with tympanoplasty The types of Tympanoplasty Type-1: reconstruction of the tympanic membrane (ossicular chain intact and mobile). Type-2: malleus handle absent, reconstruction of the tympanic membrane over the malleus remnant and long process of incus. Type-3: malleus and incus absent, reconstruction of the tympanic membrane over an intact and mobile stapes (myringostapediopexy) with stapes acting as columella. Type-4: mobile stapes footplate exteriorized with reconstruction of the tympanic membrane as a round window buffle. Type-5: stapes fixed, fenestration. Aims and Objectoves: 1. To findout hearing status before mastoidectomy. 2. To find out hearing status after canal wall down mastoidectomy with and without reconstruction. Methods: This study was conducted using following methods and materials: Type of Study : Prospective Study Place of Study : ENT department of Mymenshingh Medical College Hospital (MMCH), Sir Salimullah Medical College and Mitford Hospital (SSMC & MH), Dhaka and Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka. 147 Post operative hearing status in canal wall down mastoidectomy Sheikh Mohammad Rafiqul Hossain et al


Introduction:
Atticoantral variety of CSOM most commonly involves the epitympanum & usually associated with cholesteatoma. Cholesteatoma is histologically benign but may be aggressive locally and associated with significant morbidity or mortality if untreated. 1 The choice of treatment of cholesteatoma is surgery for which the goal is total clearance of disease, to obtain a safe, dry ear, restoration or maintaining the functional capacity if possible. 2 There are different surgical modalities of treatment according to the extent of cholesteatoma and amount of destruction such as suction clearance, intact canal wall procedures (cortical mastoidectomy, combined approach tympanoplasty) and canal wall down procedures (atticotomy, atticotoantrostomy, Modified radical mastoidectomy and Radical mastoidectomy) 3. In the early days of chronic ear surgery radical mastoidectomy was the operation of choice but poor hearing and high incidence of chronic or intermittent discharge were the limitations of this procedure. To overcome this disadvantage modified radical mastoidectomy was proposed and most commonly performed. 4,2 In intact canal wall procedure there is good preservation of hearing but more chance of incomplete clearance or recurrence of disease. Canal wall down procedure causes disease clearance properly but the disadvantage of poor preservation of hearing which can be overcome by reconstructive surgery. 1,4 The techniques and concepts of modern reconstructive middle ear surgery came into the field when Moritz (1952), Zollner (1953,1955), Wullstein (1953Wullstein ( , 1956 in Germany introduced tympanoplasty operation . 2 Canal wall down procedure may be with or without reconstruction such as tympanic membrane, ossicular chain or posterior canal wall reconstruction. To preserve and improvement of hearing, prevent discharge and recurrence, now a days canal wall down mastoidectomy with reconstruction such as type III tympanoplasty under magnification is a modern advancement in otology. 2,3 In most of the patients of chronic suppurative otitis media, Pure Tone Audiometry shows the hearing loss ranges from mild to severe depending on extent of the disease. In canal wall down mastoidectomy without reconstruction there is destruction of ossicles and/or Tympanic membrane for complete clearance of disease. The postoperative audiometric evaluation shows further hearing loss. On the other hand canal wall down mastoidectomy with reconstruction i.e. tympanoplasty, ossiculoplasty improves hearing in variable amount. In the study of MU Ahmed (2005) and Ajalloueyan (2006) shows that significant number of patients receiving such procedure have improved their hearing status. 3,4 Careful follow up, by clinical, radiological and audiometric means are essential to make a comment about hearing status of the patient. The worldwide practice of performing such surgery and it's good outcome has encouraged to do this research work.

Modified radical mastoidectomy with tympanoplasty
The types of Tympanoplasty 2 Type-1: reconstruction of the tympanic membrane (ossicular chain intact and mobile).
Type-2: malleus handle absent, reconstruction of the tympanic membrane over the malleus remnant and long process of incus.
Type-3: malleus and incus absent, reconstruction of the tympanic membrane over an intact and mobile stapes (myringostapediopexy) with stapes acting as columella.
Type-4: mobile stapes footplate exteriorized with reconstruction of the tympanic membrane as a round window buffle.
2. To find out hearing status after canal wall down mastoidectomy with and without reconstruction.

Methods:
This study was conducted using following methods and materials:

Duration of Study
One year, January 2008 to January 2009.

Study Population
Patients of CSOM (atticoantral varity) admitted for canal wall down mastoidectomy.

Sample size (n)
Group I: 20 Patients of canal wall down mastoidectomy without reconstruction.
Group II: 20 Patients of canal wall down mastoidectomy with reconstruction (type-III tympanoplasty).

Total number of patients was 40.
Data Collection: Relevant data were collected in a preformed data collection sheet for each of the patient.
Analysis of data and results: All data checked and verified thoroughly to reduce the inconsistency. The numerical data obtained from this study compiled and analyzed. The results are presented here as tables and figures.

Results:
Table I Distribution of the types of surgery (n = 40).

Types of surgery
No of patients Percentage canal wall down mastoidectomy without reconstruction 20 50 canal wall down mastoidectomy with reconstruction 20 50  Table XII shows that ear discharge after 4 weeks of operation was 40% and at the end of 8 weeks which was 20%. Two case having preoperative facial weakness in which function did not return after 8 weeks. None of the patients developed dead ear. Dry cavity in CWD with tympanoplasty group (90%) was higher than CWD without tympanoplasty group (70%).    Closer of AB gap (9.77 dB) occurred after CWD with reconstruction.

Discussion:
Chronic suppurative otitis media with or without complications affects a large number of patient in developing countries and is quite common in our country especially the younger and low socioeconomic groups. In attico antral variety of chronic suppurative otitis media (CSOM), cholesteatoma is usually present in middle ear & mastoid air cell system, which is mainly responsible for different complications. 5 Goals of surgical management of cholesteatoma include the eradication of disease, restoration of hearing and restoration of normal anatomical configuration. Prior to 1950s, the only surgery that was popularly recommended and used for middle ear cholesteatoma was radical or modified radical mastoidectomy. Now a days canal wall down mastoidectomy with tympanoplasties are widely performed. Convincing evidence exists that recurrence is reduced in CWD mastoidectomy with tympanoplasty and the hearing outcome is not sacrificed 6 .
In this study, patients of atticoantral varity of CSOM were divided into two groups: Group-1, Patients who underwent CWD mastoidectomy without reconstruction and group-II, patients who underwent CWD mastoidectomy with reconstruction. Each groups comprises 20 patients.
In the present study the age range were from 8 years to 50 years. The average age was being 21 years. The highest number of patients (45%) were in 11-20 years age group. The younger age groups suffer more as because of cellular mastoid, horizontal position of Eustachian tube and enlarged adenoids and re-current upper respiratory tract infections, which is supported by other studies. 2,7 Bathing habit of the study population revealed that major group (75%) had the habit of bathing in pond and river which was a factor of reactivation of ear infection and complication, this finding had also supported by others. 6,8 In this series male (70%) were more affected than female (30%) with a male and female ratio of 2.3:1 which also showed in different studies. 27,31,32 Female was less in number because they are less cared in society, they hardly attended the hospital and there are few bed allocation for the female as compared to male. 6 Among the study group right ear involvement was 50%, 40% in left ear and 10% in both ear.
In this study group the commonest complaints were otorrhoea (100%) and hearing impairment (100%). which was also supported by other studies 27 cholesteatoma was present in all patients (100%) and granulation tissue in 40% cases, that is also similar to other studies 9 .
In the present study, 67.5% had attic perforation and 32.5% had posteriosuperior marginal perforation. This findings are more or less similiar to other series where attic perforation were more than the posteriosuperior marginal perforation. 5,10 Vertigo was present in 2 (5%) cases, vomiting in 3 (7.5%) cases after canal wall down mastoidectomy which disappeared within 1 st week of operation. This may be due to surgical or thermal stimulation of labyrinth. Among the 2 (5%) cases of facial paralysis, In group II preoperative AC was 35-75dB (mean 58.3 dB) BC was 10-35dB (mean 20.75dB). So, the preoperative air bone gap was 37.55dB, while post operative AB gap was 10-45dB (mean 27.78dB). So the mean hearing gain was 9.77dB (with a range between 5-30dB). This result was more or less similar to other study 14,15,16 In both groups, during MRM, partially diseased ossicle and incus were removed resulting in discontinuity of ossicular chain and deterioration of hearing. In some cases, the gap between the disrupted ossicular chain was bridged by cholesteatoma and thus hearing was maintained. But after removal of disease, continuity of ossicular chain was lost and resulting in deterioration of hearing. 16 In addition, in case of CWD mastoidectomy with tympanoplasty, sometimes medialization of graft occurs, for which middle ear cavity is not maintained and possibly eustachian tube function is not established properly. As a result deterioration of hearing occurs 17 .

Conclusion:
Early detection and management of chronic suppurative otitis media with cholesteatoma should be our goal to prevent complication and post operative care and follow up are imperative to prevent recurrence and promotion of life. The functional results of this study support the importance of type III tympanoplasty in conjunction with CWD mastoidectomy. In fact reconstruction following mastoidectomy not only improves the hearing but also causing dry ear and prevention of complication and thus improves the quality of life.