A Simple Technique to Obliterate Canal Wall Down Mastoid Cavity Concurrently in Squamosal Otitis Media: Our Experience

Abstract

Chronic suppurative otitis media is a type of otitis media defined as a long standing infection of a part or whole of the middle ear cleft. Squamosal type of CSOM involves parsflaccida characterised by the formation of cholesteatoma. The present study is retrospective analysis of records of patient who underwent canal wall down mastoidectomy with obliteration of cavity using posteroinferiorly based musculoperiosteal flap with autogenous cartilage and bone pate. Study include patients who underwent canal wall mastoidectomy with cavity obliteration at Tertiary care Hospital Yavatmal, Maharashtra, India; during 2 year period of 2016–2018. 41 patients (42 ears) who underwent canal wall down mastoidectomy with cavity obliteration procedure were included and 06 patients were excluded as they failed to follow up. The outcomes were measured by Marchant et al. grading scale. As per the study it was observed that 88% (37 out 42 ears) got adequate control of infection with dry cavity, while 12% (5 ears) failed to attain dry ear. So it’s been concluded that canal wall down mastoidectomy is an effective surgical procedure in management of squamosal type of CSOM and mastoid obliteration is proved technique to improve outcomes of canal wall down procedure. Technique used to develop posteroinferiorly based flap to obliterate cavity in our study is simple modification of routine surgical steps commonly practiced by otologist helpful in reducing cavity size and promoting healthy epithelization. Cavity obliteration technique used in study is very effective and simple to develop dry and trouble free cavity in around 90% cases.

Introduction

Otitis media is defined as inflammation of middle ear cleft. Chronic suppurative otitis media is a type of otitis media which is defined as a long standing infection of a part or whole of the middle ear cleft. Otorrhea for period of 6 weeks to 3 months, despite medical treatment, are recognized as CSOM cases. The WHO requires only 2 weeks of otorrhoea to call it as chronic disease. Atticoantral type of CSOM involves pars flaccida and is characterized by the formation of cholesteatoma. It is generally considered to be at risk of developing intracranial or extracranial complications [1, 2].

In 1890, Zaufal described radical mastoidectomy for creating an open cavity which was necessary for treatment of CSOM with cholesteatoma. Further modified by Bondy to call it as Modified radical mastoidectomy (MRM). Later Jansen, Sheehy and Patterson gave concept of canal wall up and down mastoidectomies [3].

Aim of surgical treatment in CSOM is to achieve a safe and dry ear with hearing preservation and reconstruction. Comparing two surgical treatment option for CSOM with cholesteotoma, though canal wall down mastoidectomy offers lower risk of recurrence (2–10%) as that for canal wall up procedure(30–63%) by virtue of excellent exposure for disease eradication, it also offers potential disadvantages of cavity problems of recurrent otorrhoea, problem with water exposure or vertigo due to caloric effect, dependency on doctor for regular cleaning of cavity, difficulty in hearing aid fitting if required and cosmetic concern [4–6].

To eliminate these cavity problems, Mosher in 1911 gave a concept of mastoid cavity obliteration [7]. Mastoid obliteration procedures can be classified into two main categories:

1. Free grafts which can be biological (cortical bone pate, allogenous/autogenous bone chips, cartilage, fat and fascia [8]) and non-biological (hydroxyapatite crystals, calcium phosphate ceramic granules and bioactive glass ceramic) [9–11] and

2. Local flaps which includes the Palva flap (Meatally-based musculoperiosteal flap) [12], middle temporal artery flap, Hong Kong flap [13], temporoparietal fascial flap (TPFF) [14], pedicled superficial temporalis fascial flap [15], postauricular-periosteal-pericranial flap [16], temporalis muscle flap [17], inferiorly based fascioperiosteal flap [18] and postauricular myocutaneous flap [19].

In present study at our centre we used posteroinferiorly based musculoperiosteal flap along with autogenous cartilage and bone pate to obliterate CWD mastoid cavity.

Study Design

Present study is retrospective analysis of records of patients underwent canal wall down matoidectomy with obliteration of cavity using posteroinferiorly based musculoperiosteal flap with autogenous cartilage and bone pate.

Materials and Methods

Study includes patients who underwent canal wall mastoidectomy with cavity obliteration at department of Ent, Shri Vasantrao Naik Govt Medical College and Tertiary care Hospital, Yavatmal, Maharahtra, India during 2 year period of 1st January 2016 to 31st December 2018. During this period, 51 patients (52 ears) undergone canal wall down mastoidectomy operation for CSOM with cholesteotoma or granulation disease or both. Obliteration of cavity is not done in 4 patients as 1 patient had extradural abscess, 2 patients had preoperative facial nerve palsy and 1 patient was suspected to have intraoperative facial nerve injury which turned to be facial palsy postoperatively. Out of 47 patients (48 ears) who underwent canal wall down mastoidectomy with cavity obliteration procedure, 41 patients (42 ears) were included in study and 06 patient were excluded as they failed to follow up for minimum period of 12 month postoperatively.

The outcome of procedure were measured by looking at control of suppuration of mastoid cavity and by achieving a dry and low maintainance cavity which was assessed by previously developed grading scale by Marchant et al. [20] (Table 1). As it requires a period of around 3 month to epithelize mastoid cavity and absorption gel foam pieces kept in cavity, we applied this scale from 3 month post operative follow up visit onward till 12 month post operative follow up visit. Grade 0 represents a totally dry, healed ear and Grade 3 represents obvious failure to control infection, whereas Grades 1 and 2 present adequate, but not perfect control of suppuration. Out of all assessed grade at all follow up visit,the one which is highest taken as final grade for patients between follow up period of 3–12 postoperative month follow up visit.

Table 1.

Grading system to assess control of infection after surgery [20]

Grade	Description
0	No episode of otorrhea, and no pus or granulation tissue on otology examination
1	One episode of otorrhea of < 2 week duration in a 3-month period or no otorrhea but a subjective feeling of wetness in the ear
2	More than one episode of otorrhea in a 3-month period, or an episode of otorrhea lasting more than 2 week, or otologic examination showing localized granulation tissue/pus that was promptly cured with antibiotic drops, curettage, or silver nitrate cautery
3	Constant purulent otorrhea on a daily basis, or otologic examination showing extensive granulation tissue, or need for a revision procedure to control infection

Surgical Technique

After complete evaluation of patient, pre-aneasthetic checkup and written informed consent, patient was posted for procedure under general aneasthesia. Head was turned to opposite side and local infiltration given with 2% lignocaine with 1:100,000 adrenline. Postauricular incision was taken 0.5–1 cm posterior and parallel to retroauricular groove from root of helix to mastoid tip (Fig. 1) [21]. Release incision given superiorly and inferiorly sometimes if required. Soft tissue dissection was done taking precaution that plane of dissection is as close as possible to medial or posterior surface of conchal cartilage so that maximum soft tissue left over postauricular mastoid region which will be going to be used for obliteration. After harvesting temporalis facia graft, ‘T’ shaped bone deep incision was given (Fig. 3) and posteriorly based musculoperiosteal flap dissected which could be used further for obliteration (Fig. 2) [21]. Posterior meatotomy performed and tympanomeatal flap elevated. While drilling cortical bone for mastoidectomy, bone pate collected taking precaution that no any granulation tissue or cholesteotoma is included. Canal wall down mastoidectomy was performed exteriorizing all mastoid air cells with anterior and posterior epitympanum and hypotympanum. Facial ridge lowered adequately and cavity saucerised and made even adequately and whenever required bony EAC in anterioinferior region was drilled so that tympanic annulus could be visualized all around. Saline wash was given thoroughly. Wide conchomeatoplasty done by removing piece of conchal cartilage. Appropriate ossiculopasty done depending on presence or absence of stapes suprastructure and status of footplate using conchal cartilage. Posteriorly based musculoperiosteal flap is reshaped as shown in Fig. 4 so that adequate length posterioinferiorly based flap is used along with cartilage pieces and bone pate to oblitarete cavity. Cartilage and bone pate used to fill deepened part of cavity which is covered by posteroinferiorly based musculoperiosteal flap which is further covered by temporalis fascia. Remaining part of tympanomeatal flap is kept over temporalis fascia graft. All assembly was kept in place using ear drop soaked pieces of gel foam and antibiotic ointment impregnated ribbon gauze. Wound is closed in layer with 3–0 vycril and 3–0 silk suture. Mastoid dressing applied.

Fig. 1.

Showing postaural wildes incision [21]

Fig. 3.

Musculoperiosteal ‘T’ shaped incision

Fig. 2.

Modification of posterior musculoperiosteal flap. Orange line shows additional insicion to modify posterior musculoperiosteal flape to new posteroinferiorly based musculoperiosteal flap shown as “a b c” in figure [21]

Fig. 4.

Surgical intraoperative picture showing obliteration

Result

During period of 2 year included in study, out of 52 canal wall down mastoidectomy procedure performed in 51 patient for chronic suppurative otitis media (CSOM) with cholesteatoma or granulation or both, records of 42 canal wall down mastoidectomy with obliteration procedure in 41 patients were analysed. Out of 41 patients 24(58.53%) were male and 17 (41.46%) were female.

Most of patients were between 20 to 50 years of age group i.e. 24 (58.53%) patients, 13 (31.70%) patients were below 20 years of age and only 4 (9.75%) patients were above 50 years of age. Youngest patient was of 5 years of age and oldest one was of 71 years with mean age of 28.5 years.

16 patients had disease in their left ear, 12 patients had right sided disease while 13 patients had disease in their both ear. Out of these 13 patient only 1 patient was operated for both ear and 7 patients underwent right sided and 5 patients underwent left sided procedure. Of 42 operative procedure 37 were primary procedure while 5 procedures were revision operated elsewhere previously.

All 41 patients reported with otorrhoea while 25 (61%) patients had complained of decreased hearing on one or both side. Earache was reported by 09 (22%) patients. 03 (7.31%) patients had swelling behind ear and 01 (2.5%) patient each complained of giddiness and ear bleed.

Of all squamosal disesase, 28 (66.66%) ears had cholesteotoma sac while 10 (23.80%) ears had cholesteatoma sac with granulation disease. Only 4 (9.52%) ears had granulation as disease.

In all patients, disease involve attic and mastoid antrum but mesotympanum was involved in 28 (66.66%) ears and other peripheral mastoid air cells were involved in 26 (61.9%) ears.

Incus was most commonly eroded ear ossicle in 36(85.71%) ears followed by malleus in 26 (61.9%) ears and stapes suprastructure in 18 (42.85%) ears. Stapes footplate was not eroded or fixed in any case. 06 (14.63%) ears had intraoperative finding of lateral semicircular canal erosion/ fistula.

As described previously, efficacy of obliteration procedure in controlling of infection after canal wall down mastoidectomy is assessed by previously developed grading scale by Marchant et al. We considered only worst grade at any follow up visit during 3–12 month postoperative period and in that grade 3 ear procedure is considered as failure of obliteration procedure to control infection while grade 0 to grade 2 is considered as successful procedures in controlling infection adequately. In our study, as per Table 2, 37 (88%) ears achieved adequate control of infection while 05 (12%) ears failed in controlling infection. Patients with cholesteatoma sac only type of disease had 93% rate of successfully controlling infection while only 50% patients with granulation tissue as type of disease were successful in controlling infection adequately.

Table 2.

Efficacy of obliteration procedure in control of infection after surgery as assessed by grading scale

Grades	Numbers of patients ear as per type of disease			Total (%)
	Cholesteotoma sac only (%)	Cholesteotoma sac with granulation tissue (%)	Granulation tissue only (%)
Grade 0	20 (71)	05 (50)	00	25 (60)
Grade 1	04 (15)	03 (30)	01 (25)	08 (19)
Grade 2	02 (07)	01 (10)	01 (25)	04 (09)
Grade 3	02 (07)	01 (10)	02 (50)	05 (12)
Total	28	10	04	42

Worst grade at any follow up visit during 3–12 months postoperative period for each ear is considered in table

1 out of 5 failure was attributed to postoperative meatal stenosis with collection of debries and otorrhoea. This patient was adequately treated with conchomeatoplasty by removing an extra piece of cartilage from choncha and using split thickness skin graft along with debridement of mastoid cavity with no extra work needed in neo mastoid cavity. Rest 4 patients developed granulation tissue in neo mastoid cavity which were successfully managed by repeated microscopic endomeatal curettage and 10% Trichloroacetic Acid application on opd basis only (Fig. 5).

Fig. 5.

Three months postoperative image of obliterated cavity

Discussion

An ultimate aim of any surgical treatment for squamosal type of otitis media is to achieve safe and dry cavity. Squamosal type of chronic otitis media is adequately treated by canal wall down mastoidectomy as rate of recurrence is comparatively low than canal wall up mastoidectomy. But alongwith this greater advantage, it also pertain some disadvantage of large cavity like delayed healing or epithelisation of cavity, chronic ear discharge, long term dependency on surgeon for cleaning ear, dizziness and sometimes difficulty in fitting hearing aid if at all required. Though basic rules (like thorough exenteration of all mastoid cell and disease, a large meatoplasty and smooth contoured cavity with low facial ridge) to achieve trouble free cavity after canal wall mastoidectomy still carries same importance but cavity obliteration procedures may act synergistically to achieve it.

Several techniques are described to obliterate cavity using non biological material and biological autologous material. Soft tissue flaps are commonly used to obliterate cavity. Mosher is credited for his first description of use of a local flap for mastoid obliteration. After that several different flaps are described for mastoid obliteration consisting of temporoparietal fascia, temporalis muscle with fascia and with periosteum sometimes.

In our study, we used posteroinferiorly based musculoperiosteal flap along with bone pate and cartilage to obliterate cavity. We follow all routine surgical steps as that for canal wall down mastoidectomy and after completing bone drilling work, we modify posterior soft tissue flap to posteroinferiorly based msculoperiosteal flap which is just one add on step to routine canal wall down mastoidectomy procedure and can be practiced by any otologist with ease.

As per Table 3, the obliteration procedure using posteroinferiorly based musculoperiosteal flap along with bone pate and cartilage was helpful to create an acceptably dry cavity efficiently with minimal incidence of postoperative infection in 88% of obliterated ear (grade 0,1,2) (p value-0.04561 significant). The above study results were comparable to other similar studies by Merchant et.al and Ramsey et.al. Efficacy of obliteration procedure in patients with cholesteotoma sac was more as compared to that in patients with granulation tissue.

Table 3.

Efficacy of obliteration procedure

Type of disease	Number of ears with adequate control of infection (grade 0,1,2)	Number of ears with failure to control of infection (grade 3)	Total
Cholesteotoma sac only	26	02	28
Cholesteotoma sac with granulation tissue	09	01	10
Granulation tissue only	02	02	04
Total	37 (88%)	05 (12%)	42 (100%)

X2 = 6.175 d(f) 2 P = 0.04561 significant

Though 1 patient developed meatal stenosis, safety of operative procedure was confirmed as there were no other major complication reported developing of operative procedure in our study.

Conclusion

Canal wall down mastoidectomy is an effective surgical procedure in management of squamosal type of chronic suppurative otitis media and mastoid obliteration is proved technique to improve outcomes of canal wall down procedure. Technique used to develop posteroinferiorly based flap to obliterate cavity in our study is simple modification of routine surgical steps commonly practiced by otologist. This procedure is helpful in reducing cavity size and promoting healthy epithelization of neo mastoid cavity. Mastoid obliteration in canal wall down mastoidectomy using posteroinferiorly based musculoperiosteal flap along with bone pate and cartilage is very effective and simple technique to develop dry and trouble free cavity in around 90% cases.

Compliance with Ethical Standards

Conflict of interest

There is no potential conflict of interest relevant to this study.

Ethical Approval

Permission from Institutional ethics committee will be obtained before the start of study. Protocol will be submitted to Institutional Ethics Committee for approval. Study will be started only after permission from Institutional Ethics Committee. Throughout the study, complete confidentiality of data will be maintained.

Informed Consent

Informed consent was obtained from all individual participants included in the study.