Introduction
Although myringoplasty obtained high graft success rate for repairing chronic perforation with the development of endoscopic and graft technique, the repairing of marginal perforation remains a challenge because of absence of the remnant tympanic membrane (TM).Reference Sun1, Reference Bluher, Mannino and Strasnick2 Thus, raising the tympanomeatal flap via external auditory canal (EAC) incision was recommended to strengthen the graft, which was time-consuming and resulted in EAC stenosis, cholesteatoma and the risk of chorda tympani nerve (CTN) injury.Reference Bluher, Mannino and Strasnick2–Reference Takihata, Kurioka, Mizutari and Shiotani6 In addition, most of graft technique required overlapping 1–2 mm of graft and perforation margins, on the contrary, overmuch graft is not easy to smooth and leads to graft displacement after lateral packing of the graft.Reference Sun1, Reference Choi, Kim, Na, Lee, Lee and Oh7, Reference Vashisth, Yadav, Kumar, Gupta, Goel and Raheja8
With the deepening understanding resulting from clinical study, traditional procedures have been changed for the myringoplasty. Clinical studies showed that the graft healing process experienced the dilation of the blood vessels of the remnant TM, graft clinical inosculation, graft neovascularisation and graft epithelisation following cartilage myringoplasty.Reference Lou, Lou, Jin, Sun and Chen9–Reference Wu and Lou13 Not trimming the perforation margin did not affect the graft neovascularisation and success rate.Reference Lou, Lou, Jin, Sun and Chen9–Reference Lou, Lou and Chen11 In addition, EAC packing is a traditional practice following myringoplasty for most otologists.Reference Nakhla, Takwoingi and Sinha14, Reference Borgstein, de Zwart and Bruce15 However, some scholars recently found that the absence of EAC packing did not affect the graft success.Reference Lou, Lou and Chen11, Reference Lou, Lou, Lv and Chen12 These previous studies have introduced new thinking for myringoplasty: Will satisfactory graft results be obtained if sufficient graft is accumulated at the perforation margins? The objective of this study was to compare the graft outcomes between endoscopic cartilage inlay myringoplasty with free perichondrial flap fold (FPF) technique versus raising the tympanomeatal flap (RTF) technique for repairing large marginal perforation.
Materials and methods
Ethical considerations
The study protocol was approved by the Human Research Ethics Committee of Suzhou Ninth People’s Hospital. All participants provided informed consent.
Patients and methods
This was a prospective, quasi-randomised controlled trial. Study subjects were recruited from consecutive patients listed for surgery for chronic large marginal perforations with mucosal chronic otitis media (COM) who visited the Department of Otorhinolaryngology, Head and Neck Surgery. Cases that met the following criteria were included: an adult chronic large marginal perforation with only remnant annular edge of one side, a perforation size of 1/2–3/4 of TM; dry ears for at least three months before surgery; an air–bone gap (ABG) less than 35 dB; and good pneumatisation of the middle ear and mastoid region, as shown by computerised tomography (CT). Before enrollment, CT and audiograms were performed in all patients. The exclusion criteria were revision cases, cholesteatoma, visible ossicular chain abnormality, acute inflammation and fungal otitis externa. Age, sex, perforation duration, side, smoking status, diabetes, myringosclerosis, operation time and pre- and hearing levels were recorded in all participants.
Audiometric data were obtained pre-operatively and six months post-operatively. Pure-tone averages (PTAs) were calculated for both air conduction (AC) and bone conduction (BC) by averaging the thresholds at 500, 1,000, 2,000 and 3,000 Hz; in most cases, a threshold of 4,000 Hz was used to interpolate the threshold of 3,000 Hz per the standards of the Hearing Committee of the American Academy of Otolaryngology-Head and Neck Surgery. Pre- and post-operative ABG was calculated by subtracting the AC PTA from the BC PTA. ABG closure was calculated as pre-operative ABG minus post-operative ABG.Reference Lou, Lou, Yu, Wang, Lv and Chen4, Reference Lou, Lou, Lv and Chen10
Participant grouping and blinding
All patients underwent endoscopic cartilage-perichondrium underlay myringoplasty.
The participants were divided into two groups using semi-random control trial. The consecutive subjects who met the inclusion criteria and provided written informed consent were allocated to FPF group and RTF group based on the order of visit time. All the perforation margins were not de-epithelialised in both groups. The surgeon was not blinded to the treatment allocation, although the participants and individual performing the assessment were blinded.
Surgical techniques
All operations were performed under general anaesthesia by the same surgeon. All the patients underwent endoscope perichondrium–cartilage graft underlay technique.
The perforation margins were not trimmed while the epithelium is removed from the distal malleus handle, if any. A tragal cartilage–perichondrium composite graft (with the perichondrium stripped from one side) was harvested from the ipsilateral tragus.Reference Sun1, Reference Lou, Lou, Yu, Wang, Lv and Chen4, Reference Lou, Lou, Lv and Chen10
FPF group
The lateral perichondrium was peeled circumferentially, with the pedicle attached to the centre of the cartilage. The cartilage graft was fashioned based on the perforation size, while all the free perichondrial flap was preserved. A notch was made in the cartilage to accommodate the malleus handle. In addition, bioresorbable synthetic polyurethane foam (NasoPore; Polyganics, Groningen, The Netherlands) was used to support the graft medially.
The perichondrium–cartilage composite graft was placed trans-perforation, the cartilage graft was positioned medial to the remnant TM and the annulus, the cartilage notch was accommodated to the malleus if any. The free perichondrial flap was placed medial to the remnant TM and the handle of the malleus.Reference Lou, Lou, Yu, Wang, Lv and Chen4, Reference Lou, Lou, Lv and Chen10 However, an excess of free perichondrial flap formed the folds and was deposited at the perforation margins (Figure 1). Lateral packing of the graft was not applied.
Diagrams illustrating of free perichondrial flap fold technique.
RTF group
The technique had been described by previous authors.Reference Sun1, Reference Lou, Lou, Yu, Wang, Lv and Chen4, Reference Lou, Lou, Lv and Chen10 The tympanomeatal flap was elevated from posterior to anterior, leaving it attached to the malleus handle (Figure 2).
Free perichondrial flap fold technique. Pre-operative perforation (A); graft placement (B, C and D); post-operative one week (E) and three months (F). Blue triangle indicated the perichondrial flap folds; yellow triangle indicated the cartilage graft.
The lateral perichondrium was peeled circumferentially with the pedicle attached to the centre of the cartilage. The cartilage graft was fashioned based on the perforation size. The free perichondrial flap was trimmed circumferentially so that it was 1–2 mm wider than the cartilage graft. A notch was made in the cartilage to accommodate the malleus handle. In addition, bioresorbable synthetic polyurethane foam (NasoPore; Polyganics, Groningen, The Netherlands) was used to support the graft medially and laterally in both groups.
The cartilage–perichondrium graft was placed trans-tympanomeatal flap into the middle ear, the cartilage was placed medial TM remnant and annulus, a notch of the cartilage graft was accommodate the malleus handle, if any. The free perichondrial flap was placed lateral to the long process of the malleus but medial to the TM remnant, annulus and the tympanomeatal flap. The tympanomeatal flap was subsequently repositioned.
Post-operative follow-up
Patients were discharged on the day after surgery. Oral amoxicillin and clavulanate potassium were prescribed for one week for all patients. The biodegradable synthetic polyurethane foam was removed two weeks later in the RTF group. Endoscopic examinations were performed in the outpatient clinic two and four weeks and six months after surgery. Any intra-operative or post-operative complications were recorded. Audiometric evaluations were performed six months after surgery. Each follow-up was performed by a surgeon who was not involved in the initial operation.
Outcome measures
The outcome measures were operation time, graft success rate, audiometric outcomes and complications. Graft success was defined as the presence of an intact graft; graft failure was defined as the presence of residual perforation after surgery. The operative time was defined as the duration from the start of surgery following anaesthesia induction to graft placement. Post-operative pain assessment was performed via the visual analog scale (VAS) score on the day of surgery and was ranked into five levels according to the scores: no pain (0), mild pain (1–3), moderate pain (4–6), severe pain (7–9), and the worst pain (10).Reference Lou, Lou, Lv and Chen10
Statistical analyses
Data were expressed as means (with standard deviations) for quantitative variables and as frequencies (with percentages) for qualitative variables. Between-group comparisons were performed using the independent-sample t-test for quantitative variables and the chi-square test for qualitative variables. The paired t-test was used to evaluate the differences in ABGs or AC thresholds. All statistical analyses were performed using SPSS, version 20 (IBM, Armonk, NY, USA). p-Values less than 0.05 were considered statistically significant.
Result
Demographic characteristics and operation time
In total, 61 ears with large marginal perforation were included. All patients completed six months follow-up. Of the 61 ears, 31 were included in the FPF group and 30 in the RTF group. Demographic data are shown in Table 1. Age, sex, perforation duration, side, smoking status, diabetes and myringosclerosis were matched between the groups.
Characteristics of patient sample
Table 1 Long description
The table compares baseline characteristics and outcomes for two patient groups: FPF (31 patients) and RTF (30 patients), with p-values for between-group differences. Sex distribution was similar (18 female and 13 male in FPF; 16 female and 14 male in RTF), and mean age was comparable (about 48 years in both groups). Perforation side, myringosclerosis, smoking status, diabetes, and duration of condition were also similar, with no meaningful differences indicated by the p-values. Operation time differed markedly: about 26 minutes for FPF versus about 51 minutes for RTF, with a statistically significant difference. Pain measured by VAS was lower in FPF (about 1.4) than RTF (about 4.7), also statistically significant. Graft success was high and similar in both groups (29 successes in each group, roughly mid-90 percent), with no significant difference. Interpretation should note that p-values reflect statistical testing and do not convey effect size or clinical importance beyond the observed group differences.
a Chi-squared test.
b Independent samples test.
FPF = free perichondrial flap fold; RTF = raising the tympanomeatal flap; VAS = visual analog scale.
Operation time and post-operative pain
The mean operation time was 26.4 plus-or-minus 3.1 minutes in the FPF group and 50.7 plus-or-minus 2.6 minutes in the RTF group, the difference was significant (p < 0.001). The average pain scores in FPF were 1.4 ± 1.1 and 4.7 ± 1.8 in the RTF groups on the day of surgery, the difference was significant (p < 0.001).
Graft success rate
Clinical inosculation of perichondrium graft and TM remnant was seen in all the perforations, followed by graft neovascularisation at post-operative one to three weeks. The perichondral flap folds were subsequently flattened and did not accumulate at the perforation margin at post-operative two to four months in the FPF group. The residual perforation was seen in 6.5 per cent (2/31) in the FPF group and in 3.3 per cent (1/30) in the RTF group; the graft success rate was 93.5 per cent (29/31) in the FPF group and 96.7 per cent (29/30) in the RTF group; the difference was not significant (p = 0.977).
Audiologic outcomes
A comparison between the pre-operative and post-operative four-tone PTAs for AC and BC is detailed in Table 2. There were no significant differences between the groups in pre-operative AC PTAs, BC PTAs or ABGs; post-operative AC PTAs, BC PTAs or ABGs; or changes in ABG through the surgery. Between the pre-operative and post-operative measurements, the mean ABG improved by 12.1 plus-or-minus 1.2 dB in the FPF group and 11.8 plus-or-minus 6.2 dB in the RTF group; this was not significant (p = 0.642) in both groups.
Pre- and post-operative audiometric characteristics of patient sample
Table 2 Long description
The table compares pre- and post-operative hearing measures between two surgical groups, FPF with 28 patients and RTF with 27 patients, using pure tone averages for air conduction, bone conduction, and the air–bone gap in decibels. Before surgery, air conduction averages were in the low 40s for both groups and bone conduction averages were around the low 20s, yielding air–bone gaps around the low 20s. After surgery, air conduction improved to about 31 decibels in both groups, while bone conduction remained about the same near the low 20s. Post-operative air–bone gaps decreased to about 11 decibels in both groups. Air–bone gap closure was about 12 decibels for FPF and about 12 decibels for RTF. Across all listed measures, the p-values indicate no statistically meaningful differences between groups, so results should be interpreted as broadly comparable rather than favoring one technique.
Note: Paired t-test.
* p-Value: Comparison between two groups in terms of gain, pre- or post-operatively.
ABG = air–bone gap; AC = air conduction; BC = bone conduction; dB = decibel; FPF = free perichondrial flap fold; PTA = pure tone average; RTF = raising the tympanomeatal flap.
Posto-perative complications
During the follow-up period, no deteriorative sensorineural hearing loss, vertigo or tinnitus occurred in both groups; also, no patients exhibited significant graft blunting, lateralisation, medialisation or atelectasis. However, 26.7 per cent (8/30) of patients reported altered taste perception and two (6.7%) experienced EAC stenosis in the RTF group. Nevertheless, these complications were not encountered in the FPF group. In addition, myringitis was encountered in six (19.4%) ears in the FPF group and in one (3.3%) in the RTF group (p = 0.118).
Discussion
Repairing of large marginal perforation remains a challenge because of absence of support of TM remnant, resulting in graft displacement.Reference Sun1, Reference Bluher, Mannino and Strasnick2 Traditional trimming of perforation margins would further reduce the contact area of graft and increase the possibility of the graft failure.Reference Lou, Lou, Jin, Sun and Chen9 Thus, RTF was used to strengthen the graft. However, Lou et al.Reference Lou, Lou, Jin, Sun and Chen9–Reference Lou, Lou, Lv and Chen12 demonstrated that not trimming perforation margins did not affect graft clinical inosculation and graft success.
In this study, the graft success rate was not significantly different between FPF and RTF groups (93.5 vs. 96.7%). The graft success rate was comparable to previous studies for repairing marginal perforations. Takahashi et al.Reference Takahashi, Motegi, Yamamoto, Yamamoto and Kojima16 reported the success rate of 98.0 per cent using interlay technique; Bedri et al.Reference Bedri, Korra, Redleaf and Worku17 reported the graft success rate of 90 per cent using double-layer graft technique; other scholars reported that the graft success rate was 95.1 per cent using lateral underlay technique,Reference Linares Casas, Ruiz and De Pauli18 94.4 per cent using L-shaped cartilage techniqueReference Choi, Kim, Na, Lee, Lee and Oh7 and 95.1 per cent using circumferential subannular technique.Reference Arora, Thakur, Kamble, Jati, Nagarkar and Thakur19 There is only an annulus but no TM remnant in some margins for marginal perforations, the cartilage graft just touched the annulus, but lacks the overlap of the annulus, thereby reduced the graft success. However, all perichondrial flaps were preserved and accumulated at the perforation margins to insure no gaps and high overlap of perichondrial flap and TM remnant/annulus in the FPF group, thereby improved the graft success rate, although RTF was not applied in this study. In addition, all the ears achieved graft inosculation and graft neovascularisation in the FPF group, although trimming perforation margins was not performed.
The present perichondrial flap fold technique was similar to tuck grafts, which has been proved to improve the graft success rate.Reference Nemade, Shinde and Sampate20 In addition, the displacement of the perichondrial flap is almost impossible because of the absence of EAC packing. Absence of EAC packing did not affect the graft success rate of underlay technique.Reference Wu and Lou13, Reference Borgstein, de Zwart and Bruce15 The residual perforation was seen in two (6.5%) in the FPF group, we speculated that it may be related to insufficient perichondrial flap. Although RTF was applied in the RTF group, the perichondrial flap was only 1–2 mm, and placed medial to the tympanomeatal flap. In addition, lateral packing could result in the displacement of the perichondrial flap along the centre of TM, thereby leaving a small perforation.
This study showed that the FPF group significantly shortened the mean operation time compared with RTF group; RTF and perichondrial flap shaping were overlooked in the FPF group. In addition, FPF group significantly reduced post-operative pain compared with RTF group. The VAS score was significantly lower on the day of surgery in the FPF group. EAC is the most pain sensitive area, especially the bony EAC near the annulus. The RTF group underwent not only RTF but also EAC packing, while the FPF group did not. Similar to previous studies,Reference Lou, Lou, Yu, Wang, Lv and Chen4, Reference Takihata, Kurioka, Mizutari and Shiotani6, Reference Choi, Kim, Na, Lee, Lee and Oh7 26.7 per cent of patients reported altered taste perception and EAC stenosis in 6.7 per cent in RTF group, while the FPF group did not. Other scholars also reported iatrogenic cholesteatoma originating from a misplaced tympanomeatal flap.Reference Ungar, Cavel, Wasserzug, Oron, Locketz and Handzel21
Previous studies showed that the graft technique did not affect the hearing improvement for the patients with normal ossicular chain.Reference Choi, Kim, Na, Lee, Lee and Oh7–Reference Lou, Lou, Lv and Chen12 Also, no significant difference was not found for ABG gain among the two groups in this study. Although FPF group has high proportion of myringitis than that of RPF group, there was no significant difference between the two groups. The FPF technique is also suitable for microscopic procedure and repairing of anterior perforation. The limitation of this study was smaller sample size and shorter follow-up; long-term follow-up of large sample sizes should be recommended in the future.
• The raising the tympanomeatal flap was time-consuming and increased the risk of the stenosis and cholesteatoma of external auditory canal and the chorda tympani nerve injury
• The perichondrial flap folds technique is time-saving and minimally invasive for repairing large marginal perforation
• The perichondrial flap folds technique may obtain similar graft success rate and hearing improvement compared to raising the tympanomeatal flap technique, with minimum complications and less post-operative pain
Conclusion
The FPF technique may achieve similar graft success rate and hearing improvement as the RTF technique for repairing large marginal perforations; however, it is simple, time-saving and minimal invasive technique.
Ethics approval and consent to participate
The study protocol was approved by the Human Research Ethics Committee of Suzhou Ninth People’s Hospital. Written informed consent was obtained from all patients and also from parents of the participants. A statement confirmed that all methods were carried out in accordance with relevant guidelines and regulations.
Consent for publication
Not applicable.
Data availability statement
All data generated or analysed during this study are included in the published article.
Funding
None.
Competing interests
The authors declare they have no conflict of interest.
Author contributions
Shen Wang: analysis of data for the work and writing the draft; Sen Yang: collection and analysis of data; Fei Zhou: design and drafting of the work, interpretation of data for the work, agreement to be accountable for all aspects of the work. The version to be published was finally approved by all the authors.
