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Sutureless tympanoplasty using acellular dermis

Anoop Raj, MBBS, MS, Ankush Sayal, MBBS, MS,P.K. Rathore, MBBS, MS, Ravi Meher, MBBS, MS, DNB

Department of Otolaryngology and Head, Neck Surgery, MAM College and Assoc. LN Hospital, New Delhi, India

Received 10 August 2009

Abstract Objective: A prospective randomized unblinded controlled trial was conducted by comparing

acellular dermis with temporalis fascia as graft materials in tympanoplasty (type 1) in terms of

operative time, postoperative pain, graft success rate, and audiologic outcome.

Study design: Forty-two patients with (inactive) chronic suppurative otitis media of tubotympanictype were randomized, matched, and divided equally into 2 groups of 21 each. One group underwent

tympanoplasty (type 1) via transcanal route using temporalis fascia graft and the other using acellular

dermis. Both groups were compared for operative time, postoperative pain, graft success rate, and

audiologic improvement in hearing.

Results:There was a statistically significant reduction in operative time (Pb.05) and postoperative

pain (P b .05) in the acellular dermis group. However, there was no statistical difference in graft

success rate (P N .05) and hearing improvement (P N .05) between both the groups.

Conclusion:Results of tympanoplasty using acellular dermis as graft material are comparable to that

using temporalis fascia in terms of graft uptake and hearing improvement. However, tympanoplasty

using acellular dermis has the advantage of shorter operative time and lesser postoperative pain.

2011 Elsevier Inc. All rights reserved.

1. Introduction

Tympanic membrane perforations are commonly seen

by the otologist. It not only causes loss of hearing but

also the patient has to face the embarrassment of a

persistently or recurrent ear discharges. It can be managed

by reconstruction of the hearing mechanism by grafting

the tympanic membrane perforation. The surgery is called

tympanoplasty, which not only gives the patient a dry ear

but also improves the hearing. Since first described by

Berthold [1] in 1878, a host of materials have been usedfor tympanic membrane grafting. These include skin,

vein, fascia, perichondrium, dura, fat, and so on [2]. All

these autologous grafts have excellent success rates of

closing the perforation. The most commonly used

autologous graft material is temporalis fascia. However,

this has its own limitations. To harvest it, an incision has

to be made, which often leaves an externally visible scar.

Also, it is difficult to harvest this material in revision

surgery where the fascia has already been used in the

previous operation.

Acellular dermis is an allograft obtained from cadaveric

or donor skin banks that has been processed to reduce its

immunogenicity by decellularizing it and screening it forHIV, hepatitis B and C, syphilis, human T-lymphotropic

virus type 1, and others. The processing leaves the

basement membrane and the extracellular matrix intact.

Because the tissue is acellular, it does not produce any

antigenic inflammatory response after implantation. The

implanted dermal matrix provides a template for migration,

repopulation, and revascularization of the patient's own

fibroblasts and endothelial cells. It is available in a freeze-

dried form and has to be rehydrated before use ( Fig. 1).

Available online at www.sciencedirect.com

American Journal of OtolaryngologyHead and Neck Medicine and Surgery 32 (2011) 9699www.elsevier.com/locate/amjoto

Corresponding author. Department of Otolaryngology and Head,

Neck Surgery, MAM College and Assoc. LN Hospital, New Delhi, J-1 (2nd

Floor), Green Park Extension, New Delhi-110016, India. Tel.: +91

9910264564, 011 26191663.

E-mail address:ankushsayal@yahoo.com(A. Sayal).

0196-0709/$ see front matter 2011 Elsevier Inc. All rights reserved.

doi:10.1016/j.amjoto.2009.10.007

mailto:ankushsayal@yahoo.comhttp://dx.doi.org/10.1016/j.amjoto.2009.10.007http://dx.doi.org/10.1016/j.amjoto.2009.10.007mailto:ankushsayal@yahoo.com

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Originally described for wound grafting in patients withburns [3,4], acellular dermis is also being used for facial

tissue augmentation, intraoral resurfacing, periodontal and

maxillofacial surgeries [5], and repair of nasal septal

perforation[6]. Use of acellular dermis in ear surgery as a

graft material can reduce donor site morbidity significantly.

A review of literature on the use of acellular dermis as the

graft material in tympanoplasty was done, and we found

that our study was the only prospective study comparing

acellular dermis with temporalis fascia as graft material in

terms of operative time, postoperative pain, graft success

rate, and hearing improvement.

2. Materials and methods

Patients were recruited over 18 months from November

2007 to April 2009 from the otolaryngology clinics. The

study protocol and consent forms were approved by the

research review committee. The study was unblinded.

During the recruitment phase, patients with (inactive)

chronic otitis media of tubotympanic type were screened

and only those patients in the age group of 18 to 50 years

with medium-sized (involving approximately 25%50% of

the tympanic membrane area based on otoscopic exami-

nation), central (involving all the quadrants) perforationswere included in the study. After application of the

exclusion criteria (previously failed tympanoplasty, cho-

lesteatoma, chronic otitis media with complication, tortu-

ous external auditory canal, and those with systemic

diseases), the study was discussed with 59 consecutive

patients with a purely conductive hearing loss (less than 40

dB). Of these, 42 patients who agreed (fully informed

written consents were taken) to be a part of the study were

informed about the study design and underwent random-

ization into 2 groups. The 2 groups were matched for any

confounding factors.

2.1. Operative procedure

All patients underwent tympanoplasty (type 1) under

local anesthesia via transcanal route and underlay technique.

In the first group, temporalis fascia was used. The graft was

harvested through a separate incision over the superior

attachment of pinna. In the second group, acellular dermis of

0.03 mm thickness was used as a graft material. Acellulardermis was hydrated in 2 saline baths for 5 minutes each

before use and tailored according to the size of the

perforation. A self-retaining ear speculum was inserted into

the external auditory canal. The margins of perforation were

visualized under the microscope and freshened, tympano-

meatal flap was elevated, canaloplasty was done (so that the

entire annulus was visible without changing the position of

the microscope or of the patient's head), and graft placed by

underlay technique. Usual canal packing was done using

gelfoam and antibiotic-coated merocel ear wick. Patients

were prescribed broad-spectrum antibiotics and analgesics

orally for 1 week. All patients were discharged on the sameday. Patients were advised dry ear precautions and regular

follow-up initially after 1 week and then at 3 weeks, 6 weeks,

and at the end of 3 months.

2.2. Operative time

Operative time was kept by an independent nurse and

included the time at which the incision for harvesting the

graft was given till the time of dressing application. This time

did not include the time used for infiltration of local

anesthesia and preparatory time before the surgery. All the

surgeries were done by the same surgeon so that the

operative time could be compared between the 2 groups.Mean and standard deviation for each group were calculated

and then compared using Levene t test for equality of

variances. Result was statistically significant if value of

significance (P) was found to be less than .05.

2.3. Postoperative pain

Postoperative pain was measured using a visual analog

scale, 6 hours after surgery. By this time, the effect of local

anesthesia had weaned off. Patients were asked to rate their

pain on the visual analog scale from 0 to 10, 0 meaning no

pain and 10 as unbearable pain. Mean and standard deviation

for each group were calculated and then compared using

Levene t test for equality of variances. Result was

statistically significant if value of significance (P) was

found to be less than .05.

2.4. Graft success rate

Graft success rate was measured in terms of closure of

perforation at the end of 6 weeks. This was documented

using a Hopkins straight 0 tele-otoscope and camera. Graft

success rate (percentage) was calculated for each group and

then compared using Fisher exact test. Result was statisti-

Fig. 1. Photograph of acellular dermis 2 4 cm in size.

97A. Raj et al. / American Journal of OtolaryngologyHead and Neck Medicine and Surgery 32 (2011) 9699

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cally significant if value of significance (P) was found to be

less than .05.

2.5. Audiologic assessment

Hearing improvement (gain in air-bone gap) was assessed

at the end of 3 months by comparing the average pre- and

postoperative air-bone gap at 500, 1000, and 2000 Hz forboth the groups. The mean and standard deviation for gain in

air-bone gap in each group were calculated and then

compared using paired t test and Levene ttest for equality

of variances. Result was statistically significant if value of

significance (P) was found to be less than .05.

3. Results

Of the 42 patients who underwent the procedure, 2

patients (1 patient from each group) were lost to follow-up.

The remaining 40 patients (20 patients in each group) werecompared in terms of operative time, postoperative pain,

graft success rate, and audiologic outcome.

3.1. Operative time

The average operative time for temporalis fascia group

was 47 minutes 10 seconds 6 minutes 10 seconds. The

average operative time for acellular dermis was 28 minutes

15 seconds 3 minutes 50 seconds. tvalue between the 2

groups was calculated using Levene t test for equality of

variances and found to be 11.87 with a degree of freedom =

38. The value of significance (P) was found to be .000 (Pb

.05) and hence significant. Thus, there was a significant

reduction in operative time when using acellular dermis as

graft material.

3.2. Postoperative pain

The average postoperative pain (measured between 0 and

10 using a visual analog scale) for the temporalis fascia

group and acellular dermis group was 6.20 0.57 and 2.77

0.34, respectively. Thetvalue was calculated using Levene t

test for equality of variances and found to be 22.98 with

degree of freedom = 38. The value of significance (P) was

found to be .000 (Pb.05) and hence significant. Thus, therewas a significant reduction in postoperative pain when using

acellular dermis as the graft material.

3.3. Graft success rate

Graft success rate for the temporalis fascia group and

acellular dermis group was 90% and 95%, respectively. In

the temporalis fascia group, there were 2 failures. One of

these developed upper respiratory tract infection followed by

otitis media and the other had failed to follow dry ear

precautions. In the acellular dermis group, there was onefailure and this patient developed upper respiratory tract

infection followed by otitis media. Pvalue was calculated

using Fisher exact test and found to be 1.00 (PN.05), hence

not significant.

3.4. Audiologic outcome

The average gain in air-bone gap (calculated by comparing

the pre- and postoperative air-bone gap on pure tone

audiometry) for the temporalis fascia group and acellular

dermis group was 14.50 6.46 and 17.00 7.67 dB,

respectively. The value of significance (P) was calculated

using pairedttest and Levenettest for equality of variancesand found to be .27 (PN.05), hence not significant.

Thus, the results of hearing improvement and graft

success rate were comparable for both the groups (Table 1).

4. Discussion

Various graft materials have been used for tympano-

plasty. Yet temporalis fascia continues to be the most

commonly used graft material. This is because temporalis

fascia is harvested from the same postaural incision, is

uniform, is available in adequate amount, and is autologousin origin. Although temporalis fascia has proven to be

effective, with a success rate of 88% to 95% in closure of

tympanic membrane perforation, its harvesting is limited by

the need for extra equipment, additional effort by the

surgeon, donor site morbidity, and increased operative time.

Acellular dermis is an alternative graft material that is

processed from human cadaver ic dermis. It has the

advantages of being acellular and thus free from any host

antigenic response. The implanted dermal matrix provides a

template for migration, repopulation, and revascularization

of the patient's own fibroblasts and endothelial cells. We

selected 0.03-mm-thick acellular dermis as this was similar

to that of temporalis fascia. Acellular dermis has been usedfor myringoplasty in a chinchilla model with similar rates of

perforation closure as temporalis fascia and paper patch

Table 1

Comparison of operative time, postoperative pain, gain in air-bone gap, and graft success rate of temporalis fascia vs acellular dermis group

Temporalis fascia group Acellular dermis group Result

Average operative time 47 min 10 s 6 min 10 s 28 min 15 s 3 min 50 s t= 11.87, significant (Pb.05)

Average postoperative pain (using VAS) 6.20 0.57 2.77 0.34 t= 22.98, significant (Pb.05)

Average gain in air bone gap 14.50 6.46 dB 17.00 7.67 dB t= 0.27, not significant (PN.05)

Graft success rate 90% 95% Not significant (PN .05)

VAS indicates visual analog scale.

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[7,8]. Downey et al[9]have found no histologic difference in

the tympanic membrane formed after repair using temporalis

fascia or acellular dermis. Fayed et al[10]and Fishman et al

[11] have used acellular dermis with graft success rate of

87.5% and 84%, respectively. Studies involving control

groups for comparison have been lacking. Two previousstudies by Benecke [12] and Dan Vos et al [13] have

compared acellular dermis with temporalis fascia for

tympanoplasty and found similar success rates and audio-

logic outcome. Our study is the first study that compares the

use of acellular dermis and temporalis fascia graft in terms of

operative time, postoperative pain, graft success rate, and

hearing improvement (Fig. 2).

The disadvantages with the use of acellular dermis are the

high cost and need for storing acellular dermis at 2C to 8C.

The price of acellular dermis gets balanced against the

potential benefits in terms of time saved, which in turn

improves the efficiency of the operation theatre in terms of

allowing greater caseload. As the technique does not involve

the use of suture material, the cost per surgery gets reduced

further. In addition to this, there are nonquantified benefits to

the patient in terms of decreased postoperative pain and

morbidity, cosmetic benefits in view of absence of a

postoperative scar mark, lesser chances of infection and

decreased postoperative recovery period during convales-

cence from a postoperative incision, and loss of work during

this period.

Because there is no need to harvest a tissue graft when

using acellular dermis, we suggest that the operation should

be performed through a transcanal approach. The transcanal

approach has the logical benefits of reduction in potentialmorbidity from infection and postoperative pain, as well as

from a cosmetic stand point. We also noted that acellular

dermis is easier to handle and manipulate during surgery as

compared to temporalis fascia, which has a tendency to fold

during insertion and while repositioning the tympanomeatal

flap. Although revision cases were not included in this study,

we believe acellular material can be an effective graft

material in such cases where availability of temporalis fascia

is a problem. Although we took a small number of patients in

this study, the results have been encouraging and larger

studies are warranted before acellular dermis is used

routinely in ear surgeries.

5. Conclusion

Acellular dermis is an effective option as a tympanic

membrane graft material and has similar success rates of

tympanic membrane closure as well as postoperative

audiologic results in comparison to temporalis fascia. Its

use can significantly reduce operative time and postoperative

pain and morbidity. It also preserves native tissues and

provides better cosmetic results by avoiding a post aural scar

mark. Its use via transcanal route can transform the

procedure of tympanoplasty into a sutureless technique that

can be performed on a day care basis. We believe that thisgraft should be included in the otologist's armamentarium

for tympanic membrane grafting.

References

[1] Glasscock ME, Kanok MM. Tympanoplasty: a chronological history.

Otolaryngol Clin North Am 1977;10:469-77.

[2] Sheehy JL, Anderson RG. Myringoplasty: a review of 472 cases. Ann

Otol 1980;89:331-4.

[3] Wainwright DJ. Use of an acellular allograft dermal matrix (alloderm)

in the management of full-thickness burns. Burns 1995;21:243-8.

[4] Wainwright D, Madden M, Luterman A, et al. Clinical evaluation of an

acellular allograft dermal matrix in full thickness burns. J Burn Care

Rehabilitation 1996;17:124-36.[5] Callan D. Use of acellular dermal matrix allograft material in dental

implant treatment. Dental Surg Products 1996;1:14-7.

[6] Kridel RWH, Foda H, Lunde KC. Septal perforation repair with

acellular human dermal allograft. Arch Otolaryngol Head Neck Surg

1998;124:73-8.

[7] Laidlaw DW, Constantino PD, Govindraj S, et al. Tympanic

membrane repair with a dermal allograft. Laryngoscope 2001;111:

702-7.

[8] McFeely WJ, Bojrab DI, Kartush JM. Tympanic membrane perforation

repair using alloderm. Otolaryngol Head Neck Surg 2000;123:17-21.

[9] Downey TJ, Champeaux AL, Silva AB. Alloderm tympanoplasty of

tympanic membrane perforations. Am J Otolaryngol 2003;24:6-13.

[10] Fayed JN, Baino T, Parisier SC. Preliminary results with the use of

alloderm in chronic otitis media. Laryngoscope 2003;113:1228-30.

[11] Fishman AJ, Marrinan MS, Huang TC, et al. Total tympanic membrane

reconstruction: Alloderm verses temporalis fascia. Otoloaryngol Head

Neck Surg 2005;132:906-15.

[12] Benecke JE. Tympanic membrane grafting with alloderm. Laryngo-

scope 2001;111:1525-7.

[13] Vos JD, Latev MD, Labadie RF, et al. Use of alloderm in type 1

tympanoplasty: a comparison with native tissue grafts. Laryngoscope

2005;115:1599-602.

Fig. 2. A and B, Postoperative (4 weeks) healed tympanic membranes using

acellular dermis as graft material.

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