A Comparative Study of Temporalis Fascia and Tragal Cartilage with Perichondrium in Type 1 Tympanoplasty

Abstract

Background: Many materials such as fascia, cartilage have been used for the reconstruction of the ear drum. Cartilage retains its rigidity and resists retraction, resorption and reperforation, even in cases with eustachian tube dysfunction. The hearing gain and uptake rate of cartilage is comparable to that of temporalis fascia. Objective: To compare hearing outcome amd graft uptake rate between temporalis fascia graft & cartilage graft. Methodology: A Quazi experimental study was conducted between January 2019-April 2020 in 52 patients who underwent Type 1 Tympanoplasty. 26 patients underwent Cartilage tympanoplasty & 26 underwent tympanoplasty with Temporalis fascia as graft. All patients underwent pure tone audiogram before surgery & 3 months after tympanoplasty and we compared the graft uptake and hearing outcome in both groups. Result: In Group A out of 26 patients who underwent temporalis fascia as graft, 2 patients had residual perforation. In group B out of 26 patients who underwent cartilage Tympanolasty 1 patient had residual perforation. In Group A 11 patients had hearing gain more than 10db. In Group B 12 patients had hearing gain more than 10 db. Conclusion: Temporalis fascia & cartilage perichondrium are equally good as graft material & we should select the graft material according to the cases.

Introduction

Tympanoplasty is a procedure where middle ear disease is eradicated and hearing mechanism is restored with or without tympanic membrane grafting [1]. Success of surgery is defined as the clearance of disease, restoration of tympanic membrane and reconstruction of a sound transformer mechanism with an airbone (AB) gap of < 20db [2].

Various graft materials like temporalis fascia, dura mater, vein tissue, fat, skin, cartilage can be used to repair the tympanic membrane perforation. Temporalis fascia is most commonly used graft material with 93–97% success rate [2]. Although temporalis fascia graft is widely used as graft material, it is challenging in cases of subtotal and large perforations. This could also be due to absence of an organized fibrous layer in healed neotympanum which makes it vulnerable for retraction with negative mesotympanic pressure which can result in recurrence of disease in long run [3]. To overcome this problem autologous cartilage graft(conchal/tragal) has been used by surgeons in past decades which gives good post operative results. Cartilage grafts should have better uptake compared to temporalis fascia due to its increased stability and resistance to negative pressure. Cartilage can be used in various ways like perichondrium cartilage island, palisade or shield graft. Cartilage is stiff material so that it can be used in adhesive otitis media and in revision cases where there the chances of failure is more due to Eustachian tube dysfunction [2].

Many studies show that even though graft uptake is more in cartilage tympanoplasty hearing improvement is more in temporalis fascia grafting [4–6]. Some studies concluded that the hearing gain after cartilage tympanoplasty is comparable with that of temporalis fascia grafting provided appropriate thickness of cartilage graft is been used [4].

This study is an attempt to compare the graft uptake rate and amount of hearing gain using temporalis fascia and tragal cartilage with perichondrium.

Materials and Methodology

This was a Quasi experimental study conducted in a tertiary care hospital over a period of 1 year. This study was conducted after approval from Institutional Ethics Committee under the tenets of Declaration of Helsinki as per National Ethical Guidelines for Biomedical Research involving human participants of Indian Council of medical Research(ICMR )2017. This study was conducted among participants with chronic otitis media, inactive mucosal disease, who underwent Type1 tympanoplasty without mastoidectomy.Subjects who are above 12 years of age were only included in this study and those with active ear discharge and revision cases were excluded from this study.

There were 52 participants who were randomly allocated to 2 groups of 26 subjects each, group A and group B. Temporalis fascia was used as graft material in group A whereas in group B, full thickness tragal cartilage with perichondrium was used. A written informed consent was obtained from all subjects. The choice of graft material to be used was explained to all subjects and their consent was obtained.

Surgical Technique

All patients underwent type 1 tympanoplasty via post aural approach under general anesthesia. Temporalis fascia was harvested in a conventional technique from the same incision, where tragal cartilage was harvested by making an incision on the medial surface of tragus and cartilage is taken along with perichondrium on one side. Special care was taken to preserve dome of tragus to avoid cosmetic deformity. Margins of the perforation were freshened. Along with fibrous annulus, a circumferential tympano meatal flap was elevated all around from bony annulus. Ossicular continuity was assessed. In Group A underlay grafting of temporalis fascia was carried out. For patients in Group B tragal cartilage with perichondrium was used as graft material. Care was taken not to override cartilage to posterior meatal wall and cartilage assembly was made to fit snugly in middle ear by placing a large piece of gel foam medially and perichondrium was draped over the posterior canal wall. After carefully placing cartilage, tympanomeatal flap was repositioned back securing the margin of flap over perichondrium. The external auditory canal was packed with medicated gel foam. Post auricular incision was closed with double layer suturing and mastoid dressing was placed. All participants were discharged after suture removal on 7th post operative day. They were kept on regular follow up after surgery. Post aural wound and graft uptake status was assessed in all follow ups. All patients underwent Pure Tone Audiogram one day prior to surgery and 3 months after surgery. At the 3rd month follow up, percentage of hearing improvement in all operated ears and graft uptake was assessed in all participants and both groups were compared.

The pure tone threshold was obtained with a calibrated Interacoustics AC 40 clinical audiometer with TDH-39 (Telephonic Dynamic Headphone) supra-aural headphones and a (radio ear) B-71 bone vibrator was to obtain air-conduction and bone-conduction pure-tone thresholds respectively. The modified Hughson and Westlake procedure (Carhart &Jerger, 1959) was used for the octave frequencies of 250 Hz to 8000 Hz for air conduction and octave frequencies 250 Hz to 4000 Hz for bone conduction.

Statistical Analysis

Statistical analysis for the data was done by using SPSS(Version 20).The P value < 0.05 was considered as significant.

Results

In our study we had included 52 patients who underwent Type 1 tympanoplasty. Out of 52 patients, Group A had 26 patients who underwent tympanoplasty with temporalis fascia as graft and Group B had 26 patients who underwent cartilage tympanoplasty. There were 14 females and 12 males in group A and 16 females and 10 males in group B. Patients between 12 and 65 years were included in the study.Average age in group A was 33 and in group B it was 30. In age category they were again divided into 4 groups, below 20, 21–30,31–40,above 40. The distribution of participants are depicted in Table 1.

Table 1.

Age and gender distribution among group A and group B

		GROUP A		GROUP B
		Count	Percentage	Count	Percentage
Age distribution	2O and below	6	23.1%	4	15.4%
	21–30	7	26.9%	10	38.5%
	31–40	5	19.2%	10	38.5%
	Above 40	8	30.8%	2	7.7%
Gender	FEMALE	14	53.8%	16	61.5%
	MALE	12	46.2%	10	38.5%

In group A graft was well taken up in 24 subjects and 2 subjects had residual perforation Both were small central perforations. In the first visits graft was well taken up in both. Whereas in group B graft was well taken up in 25 subjects and 1 subject had residual perforation.2 subjects with residual perforation in Group A had bilateral disease and other subjectin Group B had upper respiratory tract infection soon after surgery which could be the reason for graft failure. This is depicted in chart 1

Chart 1.

Graft uptake in temporalis fascia graft Vs cartilage graft

Mean PTA, before and after surgery as well as mean ABG before and after surgery was assessed in both groups. 5 subjects(19.2%) had worsening of hearing following surgery in Group B including the failed case. In Group A all patients had hearing gain post surgery including the 2 cases with residual perforation. Both residual perforation in group A was small in size. In group A 2 cases with small residual perforation had a ABG gain of 1.7db and 5db .As depicted in Table 2, in group A, mean PTA preoperative and post operative were 52db and 37 db and mean Air bone gap (ABG) preoperative and post operative were 29& 17db respectively. In group B, mean PTA preoperative and post operative were 59db and 46 db and mean Air bone gap (ABG) preoperative and post operative were 32 & 21db respectively. Preoperative and post operative mean ABG of both groups are depicted in chart 3. In Group B the failed case hearing worsened after surgery by 13 db.

Table 2.

Showed average audiological values in Group A and Group B

	A	B
Pre operative PTA	52db	59db
Post operative PTA	37db	46db
Pre operative ABG	29db	32db
Post operative ABG	17db	21db
Hearing gain	12db	10db
Hearing loss	0db	0.7db

Chart 2.

Showed hearing gain in Group A and Group B

The comparison of preoperative air bone gap and post operative air bone gap in each groups was analysedusing paired T test. The pre and post operative air bone gap difference was highly significant within each groups. Whereas while comparing preoperative and post operative air bone gap between group A and group B which was analysedusing independent T test the difference was not significant

Table 3.

Comparison of ABG before and after surgery within group and between group A &group B

							Significance between pre-post		Compare between the group
Group		N	Mean	Std. Deviation	Mean difference	s.d of difference	t test p value		t test p value
Group A	PRE ABG GAP	26	27.68	11.70	11.65	9.55	0.000	HS	0.498	NS
	POST AB GAP	26	16.02	8.31
Group B	PRE ABG GAP	26	31.78	14.77	9.70	11.06	0.000	HS
	POST AB GAP	26	22.08	11.07

Chart 3.

Comparison of Air bone gap before and after surgery in group A and group B

In Group A,11 patients (42.3%) had hearing gain (pre op ABG-postop ABG) more than 10db and 15(57.7%)had hearing gain less than 10 db. In Group B, 12 patients(46.2%) had hearing gain more than 10 db whereas 14 patients (53.8%)had hearing gain less than 10 db which is depicted in chart 2.

Discussion

A successful tympanoplasty include eradication of middle ear disease, prevention of ear discharge, and achievement of good hearing mechanism [1]. The demand of cartilage have increased in ear surgery as it is easily obtainable and due to its high acceptance as a graft material. The tragal cartilage receives its nutrition by diffusion [7]. Tragal cartilage is composed of collagen type II and have higher tensile strength than temporalis fascia [8]. In cases like recurrent perforations, total perforations, and severely atelectatic tympanic membranes, bilateral ear diseases tragal cartilage is a preferred grafting material because of its increased resistance to negative middle ear pressure [9].

Age is a a negative prognostic marker in success of ear surgery. Graft success rates and hearing gain significantly decreased gradually with advancing age [5, 10]. In our study we observed that 3 patients who had graft failure were in age group 30–40.Audiological examinations in elderly patients usually have a sensorineural or mixed hearing loss, and the functional outcomes of the surgery may not be as good as those in younger patients. In our study also we observed that hearing improvement was less than expected in those with mixed hearing loss.

Bilateral chronic otitis media is a bad prognostic marker in ear surgery and can reduce the graft uptake. In this study also we observed that tympanoplasty was less successful in patients with bilateral chronic otitis media. In subjects with bilateral chronic otitis media, cartilage graft tympanoplasty is more successful than tympanoplasty with temporalis fascia as graft material [11]. In our study 2 patients in Group A who had residual perforation had bilateral disease. Even though we couldn’t achieve anatomical success in those patients, the functional outcome was good as both of them had improved hearing because the residual perforation was small in size. 1 graft failure in in cartilage group had bad upper respiratory tract infection soon after surgery and that was also bilateral disease, which could be the reason for failure.Graft failure rate was more in temporalis group than cartilage group, although the difference is not significant.This suggest that the selection of graft is more important in ear surgeries than bilaterality of disease to avoid graft failure.

Actively discharging earat the time of surgery is considered by many as a negative prognostic factor [4]. In our study we have excluded all subjects with active chronic otitis media.

Small perforations have good preoperative hearing and are easier to close. Dornhoffer et al. [12, 13]. In our study also we observed that, patients with small perforation and miod hearing loss gained well from the surgery.

Temporalis fascia remains the most frequently used graft material for tympanoplasties. The newly formed tympanic membranes often lack an intermediate layer of elastic fibres, which serves to resist the negative middle ear pressure resulting in re-perforation, particularly when the initial perforation is large and the eustachian tube is dysfunctional. Furthermore, the blood supply to the central part of the newly formed tympanic membrane is usually so poor that re-perforation occurs easily [3].

Cartilage retains its rigidity and resists retraction, resorption and reperforation, even in cases with eustachian tube dysfunction. One disadvantage of cartilage tympanoplasty is opacity of tympanic membrane and difficulty in assessing middle ear status after surgery as impedance tympanometry is unreliable after cartilage tympanoplasty and will give type B tympanogram owing to the noncompliant nature of the graft, despite having normal hearing. [12]

The graft take up rate is not a problem with tragal cartilage, the only problem with it is its effect on the hearing due to its thickness. Zahnert et al. examined the frequency response function of the tragal cartilage with laser Doppler interferometer. There were lower frequencies losses where ear drum defects were reconstructed with thick pieces of cartilage. They concluded that a cartilage plate with a thickness of less than 0.5 mm gave the lbetter hearing outcome. He suggested that the ideal acoustical thickness of cartilage should be about 0.5 mm3 [14].

The high-risk perforation comprises a revision surgery, anterior perforation a perforation larger than 50%, or a bilateral perforation, all of which have been shown to be associated with increased failure rates. In these cases, cartilage can be used for reconstruction of the tympanic membrane [12, 15].

In a study conducted by Khan et al. [16]they found that 0.5-mm thick cartilage maintains mechanical stability and reduce sound energy loss during sound transmission. So sliced tragal cartilage with perichondrium(0.5 mm)is superior to full thickness cartilage graft.^[16Even though sliced tragal cartilage with perichondrium is superior to full thickness cartilage graft, the surgical expertise is required to slice and place the sliced tragal cartilage. When the perichondrium cartilage is thinned, the graft curls unacceptably toward the side with the perichondrium, making placement difficult. This curled graft needs expertise to place in an underlay manner compared to the full thickness graft.Hence full thickness grafts are better for reconstruction. [12].

In our study we have used tragal cartilage full thickness with perichondrium as graft material which could be the reason for low failure rate by avoiding curling of the graft which can happen while slicing the cartilage. Poorer hearing gain and higher air bone gap in the cartilage group may be attributed to the use of full thickness tragal cartilage, thus blocking the transmission of sound to the ossicles [5].

There is evidence that cartilage palisade tympanoplasty gives excellent graft uptake rates and good postoperative hearing outcomes for perforations of various sizes and for both primary and revision cases. This technique has remarkable results with negligible complication rates, similar to temporalis fascia tympanoplasty [15]. In study by Dornhoffer et al., palisade cartilage tyampanoplasty technique has excellent functional results for Type 1 tympanoplasty with a 96% take rate beyond 6 months. The air-bone gap closure is same as temporalis fascia tympanoplasty [12].

In our study, we found that cartilage group had worsening of hearing which could be due to the use of full thickness cartilage as graft. The current studies suggests that a cartilage graft is better than a temporalis fascia graft for tympanic membrane perforation closure. The disadvantage of less functional gain using thicker cartilage can be overcome by slicing it to achieve a thickness comparable with that of the temporalis fascia. This process also retains cartilage rigidity and so prevents recurrence, re-perforation and retraction. [3]The tragal cartilage may not of same thickness in all patients.Also, the effects of race, age, or gender in the changing thickness of the cartilage is unknown.

We have taken postoperative pure tone audiogram 3 months after surgery. Even though gel foam will absorb in 3 months persistence of same can also show air bone gap. Persistence of gel foam could also contribute to the air bone gap after surgery. Middle ear effusion was not suspected in any of 52 patients who underwent surgery hence furthur investigations was not done.

Yilmaz et al.^[20]reported that cartilage type 1 tympanoplasties were effective in both children and adult patients. In our study we excluded children and failures were seen more in 30–40 years age group.

Ozbek et al. concluded that tympanoplasty using the cartilage and temporalis fascia did not have any difference in outcome with respect to graft uptake and hearing gain [4]. Similar findings is seen in our study. Graft uptake and hearing outcome in both cartilage and temporalis fascia group was same. Even though hearing outcome was better in temporalis fascia group, it was not statistically significant to prove that temporalis fascia group has good hearing outcome.

Kirazli et al. [6] found remarkable difference between fascia and cartilage tympanoplasty groups in term of postoperative air bone gap. But in our study also we did not observe that difference, as 11 /26 patients in temporalis group and 12/26 patients in cartilage group had more than 10 db ABG gain. Likewise in another comparative study they did not find any significant difference in hearing outcome between temporalis fascia nad cartilage on long term follow up [17].

Conclusion

Temporalis fascia and cartilage perichondrium are equally good as graft material.Cartilage grafting can be done in chronic otitis media with large perforations or in patients with recurrence and in case of bilateral disease. Partial thickness cartilage grafting is difficult and need surgical expertise. Cartilage grafting done by an expert surgeon (partial or full thickness)will give good post operative results with respect to graft uptake as well as hearing gain.

Author Contributions

First author : Data collection, compilation, analysis, writing paper. Second author: study design, reviewing paper. Third author: Data analysis, reviewing paper.

Funding

This study is self funded.

Declarations

Competing Interests

No External /internal funding. No competing interests. Institutional ethics committee approval obtained. Informed consent taken from all participants.

Conflict of Interest

Dr Divya jacob, Dr Gangadhara Somayaji and Dr Nayana V G declare they have no conflict of interest.