Management of External Auditory Canal Anterior Wall Defect: A Case Series and Literature Review

Objectives

Although rare in etiology, anterior bony wall defects of the external auditory canal (EAC) accompanied by temporomandibular joint herniation may cause various otologic symptoms. Surgical treatment can be considered based on symptom severity because many previous case reports have highlighted its efficacy. This study aimed to review the long-term results of surgical treatment of EAC anterior wall defect and to suggest a stepwise approach when creating a treatment plan.

Methods

We performed a retrospective review of 10 patients who underwent surgical management to address the EAC anterior wall defect and its associated symptoms. Medical records, temporal bone computed tomography scans, audiometry, and endoscopic examination findings were analyzed.

Results

The primary repair of the EAC defect was the first to be surgically addressed in most cases, excluding one case with a severe combined infection. Of the 10 cases, 3 patients exhibited either postoperative complications or symptom recurrence. Six patients had resolved symptoms consequent to primary surgical repair, and four patients underwent revision surgery undergoing a more invasive procedure, such as canalplasty or mastoidectomy.

Conclusion

Primary repair of the anterior wall defect of the EAC seems to be overpromoted for lasting results but is not as promising as previously noted. We therefore propose to create a novel treatment flowchart regarding the surgical treatment of anterior wall defects of the EAC based on clinical experience.

Level of Evidence

IV.

INTRODUCTION

Various symptoms may arise in the existence of bony defects in the external auditory canal (EAC). Especially in cases of anterior EAC bony wall defects, anatomic structures from the neighboring temporomandibular joint (TMJ) may protrude into the EAC, leading to symptoms such as otorrhea, tinnitus, ear fullness, hearing loss, or otalgia (1). Numerous etiologies, including chronic inflammation of the EAC, infection, trauma, tumor, and iatrogenic injury, can cause EAC defects. A congenital bony defect of the anterior EAC wall, known as a persistent foramen of Huschke (2), is also another known etiology for this condition. When accompanied by intolerable symptoms, surgical management may be considered to repair the EAC defect.

Previous studies have reported several cases of TMJ herniation into the EAC via the anterior EAC wall defect and provided surgical treatment options for the repair. However, owing to its rarity, most case reports are confined to delineating one or two cases with successful treatment results upon short-term follow-up. None of the previous studies examined surgical complications or postoperative symptom recurrence, and the average follow-up period was merely 12.7 months (3).

Based on our previous study regarding the prevalence of a patent foramen of Huschke and its surgical treatment (4), we collected long-term follow-up data of other patients who underwent surgical repair of TMJ herniation into the EAC. In contrast to previous literature reviews, several cases showed that the primary repair of EAC wall defects was insufficient to manage symptoms because the defect size was too large, or in some cases, other complications such as infection were observed. In such instances, revision surgery was inevitable, and other surgical procedures including posterior canalplasty or canal wall-down mastoidectomy were performed. Our case series reported a total of 10 patients who underwent surgical treatment for EAC defects ranging from the primary repair of the EAC wall defect to canal wall-down mastoidectomy or even subtotal petrosectomy.

MATERIALS AND METHODS

We retrospectively reviewed patients with TMJ herniation into the EAC via an anterior wall defect who underwent surgical treatment at the Seoul Metropolitan Government Seoul National University Boramae Medical Center between March 2007 and March 2022. Nonsurgical cases of TMJ herniation were excluded because most were nonsymptomatic, incidental findings. Medical records, endoscopic and radiologic images, and surgical videos were analyzed. All patients underwent preoperative temporal bone computed tomography (CT), and the anterior bony wall of the EAC was evaluated on each axial image to locate and estimate the size of the bony defect. The defect size was measured by its maximum length, and the degree of EAC stenosis was calculated linearly at the narrowest portion of the axial CT image. Medical records were thoroughly reviewed to analyze the etiologic factors, severity of symptoms, combined complications, preoperative medical treatment, and the overall outcome of surgical treatment. The surgical approach and reconstruction material differed according to EAC defect size and associated complications.

The study was approved by the Institutional Review Board (IRB) of the Clinical Research Institute (Seoul National University Boramae Medical Center, IRB no. 10-2,202-41), and the requirement for patient consent was waived. All protocols and methods used in this study were performed in accordance with the approved guidelines and the Declaration of Helsinki.

RESULTS

The mean age of the 10 patients included in this study was 56 years (range, 22–75 yr). Seven patients were men, three were women. The mean size of the EAC defect was 8.4 × 7.6 mm (range, 3.0 × 2.4–11.2 × 16.8 mm). All patients presented with unilateral defects, and there was no laterality predominance (right/left, 5:5).

A temporal bone fracture due to head trauma was observed in four patients. One patient had previously received radiotherapy for the treatment of nasopharyngeal cancer, in which the EAC was included in the irradiation field. Seven patients exhibited otalgia and clicking tinnitus upon mastication. Furthermore, four patients showed mild progressive hearing loss. Other symptoms included ear fullness and otorrhea (Table 1).

TABLE 1.

Patient demographics and EAC bony wall defect characteristics

No.	Age, yr	Sex	Initial Symptom	Symptom Onset	Presumed Cause	Previous Treatment	Defect Site	Defect Size (mm)a	EAC Stenosis (Gr)b
1	M	40	Otalgia upon mastication	20 YA	Mandible condylar fracture (23 YA)	Mandible condylar fixation (20 YA)	Lt	11.7 × 8.4	IV
2	M	48	Tinnitus upon mastication	3 YA, posttrauma	Temporal bone fracture d/t Traffic accident (3 YA)	No	Lt	9.1 × 5.0	III
3	M	38	HL	1 DA, posttrauma	Temporal bone fracture (13 YA)	Mandible condyle, parasymphysis fracture. ORIF (13 YA)	Rt	4.1 × 5.4	IV
4	M	68	EF	18 MA	Spontaneous	No	Lt	7.4 × 6.7	IV
5	M	75	HL, otalgia	2 MA	Spontaneous	No	Rt	11.3 × 8.7	IV
6	F	54	Otalgia upon mastication	ns, over 4 MA	Spontaneous	No	Rt	3.0 × 2.4	II
7	F	22	HL	2 WA, posttrauma	EAC wall fracture (26 MA)	No	Lt	10.2 × 5.0	IV
8	M	65	Otalgia, tinnitus upon mastication	2 MA	Radiation	Biopsy (outside hospital) and Infection control	Lt	11.2 × 16.8	IV
9	F	72	Otalgia	3MA	Spontaneous	No	Rt	5.7 × 10.2	II
10	M	71	Otalgia, EF	3.5YA	Spontaneous	Defect site repair using medpore (7 MA, outside hospital)	Rt	10.1 × 7.8	III

^aAxial: maximum diameter on CT axial cut; coronal: number of CT axial cuts covering the EAC defect ×CT axial slice thickness.

^bEAC stenotic portion width/EAC width measured at a single CT axial cut with maximal TMJ bulging (Gr. I: 0–25%, Gr. II: 25–50%, Gr. III: 50–75%, Gr. IV: 75–100%).

DA, days ago; EF, ear fullness; HL, hearing loss; Lt, left; MA, months ago; ORIF, open reduction and internal fixation; Rt, right; WA, weeks ago; YA, years ago.

All patients underwent surgical treatment. A total of five different surgical techniques were practiced: primary repair of the EAC anterior wall defect (either via endaural approach or preauricular approach), postauricular canalplasty, canal wall-down mastoidectomy, and subtotal petrosectomy. Primary repair of the EAC anterior wall defect refers to exposing the EAC bony defect site by carefully dissecting the EAC skin, reducing the herniated TMJ capsule, and inserting a graft material to plug the defect site to reconstruct the bony EAC. This procedure can be achieved either via endaural approach, in which the dissection plane is made along the canal side of the anterior EAC, or via preauricular approach where the dissection plane is formed between the TMJ and anterior surface of tympanic bone. Postauricular canalplasty is a procedure of widening the EAC lumen by drilling out the posterior EAC wall and removing some air cells to make enough EAC lumen. Exposed air cells were covered using conchal cartilage slices and temporalis muscle fascia. Meatoplasty was also performed. This procedure was performed in revision cases to secure EAC patency despite herniated TMJ tissue. Canal wall-down mastoidectomy or subtotal petrosectomy was performed in exceptional cases with combined infection.

Among the 10 patients included in the study, 9 patients received primary repair of the EAC wall defect as their initial surgical operation. Three of the nine cases displayed postoperative complications or symptom recurrence, resulting in a second attempt for the primary repair or a change in surgical technique altogether, to a more invasive procedure. Six patients were resolved to undergo primary repair. Two patients underwent postauricular canalplasty, and the other two patients underwent canal wall-down mastoidectomy and subtotal petrosectomy (Table 2). The flow diagram of the review process is shown in Figure 1.

TABLE 2.

Surgical management and its outcome

Case No.	Op No.	Op Name	Approach	Reconstruction Material	Symptom Recurrence	Time till Recurrence	Interval Between Operations	f/u Period After Last Operation
1	First	EAC anterior wall repair	Endaural	Homograft Temporalis muscle fascia	Yes/Otorrhea	1.5 mo	2 mo	53 mo
	Second	Posterior canalplasty	Postauricular	Conchal cartilage-	No	—
2	First	EAC anterior wall repair	Preauricular	Porous polyethylene implant-titanium mesh complex	Yes/Persistent clicking sound upon mastication	4 mo	8 mo	34 mo
	Second	EAC anterior wall repair, revision	Preauricular	Titanium mesh	No	—
3	First	EAC anterior wall repair	Preauricular	Titanium mesh	No	—	—	20 mo
4	First	EAC anterior wall repair	Endaural	None	Yes/Recurred EF	2 mo	2.5 mo	77 mo
	Second	Posterior canalplasty	Postauricular	Conchal cartilage	No	—
5	First	EAC anterior wall repair	Preauricular	Porous polyethylene implant—titanium mesh complex	Yes/Persistent otalgia	1 mo	1.5 mo	53 mo
	Second	EAC anterior wall repair, revision	Preauricular	Titanium mesh	Yes/Ear swelling, otorrhea	3 mo	4 mo
	Third	Canal wall-down mastoidectomy, FB removal	Postauricular	—	No	—
6	First	EAC anterior wall repair	Preauricular	Titanium mesh	No	—	—	45 mo
7	First	EAC anterior wall repair	Preauricular	Titanium mesh	No	—	—	24 mo
8	First	EAC lesion biopsy (outside hospital)	Transcanal	—	Yes/Otorrhea, otalgia	No improvement	6 mo	10 mo
	Second	Subtotal petrosectomy	Postauricular	—	No	—
9	First	EAC anterior wall repair	Preauricular	Titanium mesh	No	—	—	10 mo
10	First	EAC anterior wall repair (outside hospital)	Preauricular	Titanium mesh	Yes/Recurred otalgia, EF	3 mo	8 mo	8 mo
	Second	EAC anterior wall repair, revision	Preauricular	Titanium mesh	No	—

EAC indicates external auditory canal; FB, foreign body.

FIG. 1.

Surgical treatment flowchart for TMJ herniation via EAC anterior bony wall defect. EAC indicates external auditory canal; TMJ, temporomandibular joint.

Here, we present two representative cases of EAC anterior wall defect repair in detail.

Case No. 7

A 22-year-old woman presented to our outpatient clinic with severe head trauma accompanied by left-sided hearing loss. She had injured her head 2 weeks ago in a heavily drunken state and was diagnosed with a left temporal bone fracture sparing the otic capsule. At the time of visit, her subjective hearing loss had already subsided, and she denied any other ear symptoms including ear fullness, tinnitus, otalgia, or dizziness. Apart from the recent trauma, the patient was healthy and did not present with any other medical conditions. Otoscopic examination revealed a stenotic left EAC with anterior wall bulging, concealing the tympanic membrane (Fig. 2A). Audiometry showed age-appropriate hearing with a threshold of 10 dB on both sides, without any air-bone gap (Fig. 2C). The temporal bone CT scan was obtained with a 1.0-mm axial slice width, without contrast enhancement. The bony EAC wall sustained a fracture, resulting in an anterior EAC wall defect with concomitant TMJ soft tissue herniation. The EAC defect size was estimated to be approximately 10.2 × 5 mm on the CT scan, and the bulging soft tissue occupied greater than 75% of the total width of the EAC (Fig. 2D).

FIG. 2.

A, EAC anterior wall bulging upon mastication (preoperative). B, Patent EAC wall after surgical reconstruction (postoperative 1 yr). C, Preoperative audiometry. D, Temporal bone CT scan showing left anterior EAC wall fracture with resulting TMJ tissue herniation into the EAC. CT indicates computed tomography; EAC, external auditory canal; TMJ, temporomandibular joint.

The patient underwent surgical repair of the anterior wall fracture of the EAC via a preauricular approach. Under general anesthesia, nasotracheal intubation was performed to facilitate intraoperative mouth opening. Careful dissection was performed, starting from the anterior surface of the tragal cartilage, which was extended along the anterior surface of the tympanic bone. After fully exposing the bony EAC fracture site and separating the posterior surface of the TMJ capsule from the tympanic bone, a titanium mesh was inserted to reconstruct the defect. Endoscopic examination was performed intraoperatively to confirm successful repair of the defect, with no evidence of TMJ herniation upon mastication. The stenotic EAC was effectively widened and well maintained for more than 1 year before the patient was lost to follow-up (Fig. 2B).

Case No. 5

A 75-year-old man presented with a chief complaint of right-sided hearing loss and otalgia that started 2 months before his visit. He denied any previous trauma or surgery involving the head or neck region. Otoscopic examination revealed a narrow EAC with soft tissue swelling. Audiometry showed conductive hearing loss with a minimal air-bone gap of 10 dB (Fig. 3, A and D). Temporal bone CT showed a right EAC anterior wall defect with soft tissue swelling, suspected to be soft tissue herniation via the bony defect site (Fig. 3E). The bony defect size was approximately 11.3 × 8.7 mm, and the EAC was approaching total obstruction.

FIG. 3.

A, Narrow EAC with soft tissue swelling (preoperative). B, Intact TMJ and patent EAC wall after surgical reconstruction (postoperative 4 mo). C, Intact TMJ and patent EAC wall after surgical reconstruction (postoperative 43 mo). D, Preoperative audiometry showing right-side mild conductive hearing loss. E, Preoperative temporal bone CT scan taken before the first surgery revealing right EAC anterior wall defect with soft tissue swelling. CT indicates computed tomography; EAC, external auditory canal; TMJ, temporomandibular joint.

The patient underwent primary repair of the EAC wall defect via a preauricular approach, with surgical procedures identical to the aforementioned case. A month after the initial operation, restenosis of the EAC was detected on otoscopic examination, and displacement of the titanium plate was suspected. Revision surgery for exploration and repair was performed. Although the patient seemed to recover well right after revision surgery, he returned to the clinic 3 months after the second operation because of recurrent otalgia and pus-like discharge. Despite the use of oral antibiotics and anti-inflammatory drugs, the infection did not easily subside, resulting to the removal of the titanium plate. After extracting the titanium plate, because anterior EAC wall repair was impracticable, canal wall-down mastoidectomy with canalplasty was performed to ensure a patent EAC regardless of TMJ herniation. Fortunately, TMJ herniation into the EAC did not progress over time, and the patient showed an intact tympanic membrane and patent EAC (Fig. 3, B and C) up until his last follow-up, 43 months after the final operation.

DISCUSSION

Anterior wall defects in the EAC result from several conditions. The foramen of Huschke is the most common congenital cause for anterior wall defects. The foramen of Huschke is a developmental defect of the tympanic bone, located on the anteroinferior aspect of the EAC. The ossification process of the tympanic bone starts at 9 weeks of gestation and forms an incompletely developed U-shaped bone at birth (2). The anterior and posterior prominences of the tympanic bone expand toward each other and fuse during the first postnatal year, leaving an opening medial to the point of coalescence known as the foramen of Huschke (4). The opening gradually shrinks with bone growth and naturally closes within 5 years; however, if the foramen persists, it may act as a channel connecting the TMJ with the EAC. Spontaneous TMJ herniation is associated with a persistent Huschke’s foramen.

Although asymptomatic EAC wall defects do not require treatment, if symptoms such as ear fullness, otalgia, clicking tinnitus, or hearing loss exist owing to soft tissue herniation, surgical repair of the defect site is the treatment of choice. Pharmacologic management can be effective in alleviating symptoms caused by combined infection, but the reduction of herniated soft tissue can only be achieved through surgical means. Surgical reconstruction of the EAC was initially introduced in detail by Saeed et al. (5) using an endaural approach extending to the tragus. Many different surgical techniques have emerged since then, and the present literature review mainly displays two different types of approaches in repairing EAC wall defects: the endaural approach and the preauricular approach. The preauricular approach, although unfamiliar to otorhinolaryngologists, has been well acknowledged by odontologists for providing access to the TMJ and EAC anterior wall (6). The preauricular approach is favorable because it provides a wider surgical view and ensures a more secure placement of the underlay graft. However, because otologists are more familiar with the endaural approach, surgeons may perform a more dexterous operation under a more familiar view (7). The endaural approach is aesthetically advantageous because it leaves no external scars. The direction of masticatory force is another consideration in this situation. Mouth closure usually shifts pressure to the anterior wall of the EAC in the anterior-to-posterior direction because of condylar movement. If the graft or mesh is placed nearer the EAC, it is not effective in resisting masticatory pressure. On the contrary, if the graft or mesh is placed nearer the TMJ via the preauricular approach, it can bear more pressure than the former.

The surgical procedures may differ according to the reconstruction material used. Various materials, including autologous tragal cartilage, temporalis muscle fascia, polyethylene, titanium mesh, and collagen mesh, are used to reconstruct and reinforce the EAC wall defect site. Although Ha et al. (8) stated that tragal cartilage or temporalis fascia is preferred in cases with small EAC defects measuring 3 mm or less, whereas microporous high-density polyethylene implants are favored in EAC defects measuring greater than 5 mm, there is no definite consensus regarding the reconstruction material used, and surgeons’ preference seem to play a major role in choosing which material to use. The cases dealt in our study used titanium meshes for reconstruction, as it has excellent mechanical properties and biocompatibility. Owing to its high strength and stiffness, the titanium mesh can retain TMJ tissues to prevent herniation, and its plasticity allows the surgeon to handle it in a curvilinear shape suitable for adapting to the EAC (9).

A literature review of previous case reports on TMJ herniation into the EAC was conducted. A total of 24 reports were identified, with 2 reports written in German excluded and 22 remaining reports analyzed for patient presentation, defect site and size, treatment approach, and follow-up period. A total of 32 cases were presented within the 22 publications; conservative medical or physiotherapeutic treatment was offered in 8 cases, and the other 24 cases underwent surgical operation. Aside from 1 exceptional case performing intermaxillary fixation, 23 cases conducted primary repair of the EAC wall defect. Endaural, preauricular, and postauricular approach was performed in 5 cases, 15 cases, and 1 case, respectively, with 2 cases not disclosing details regarding the surgical approach. Various reconstruction materials including autologous skin graft (2), fascia (6), cartilage (6), medpor (1), titanium mesh (7), and collagen mesh (1) were used. All of the surgical cases reported successful symptom resolution without any major postoperative complications or symptom recurrence. A minor surgical complication was reported in one case report: crepitus upon jaw movement after operation via preauricular approach. Detailed patient demographics, initial symptoms, EAC defect size, and treatment done are shown in Table 3.

TABLE 3.

Treatment for TMJ herniation via EAC bony wall defect presented in previous publications

No.	Author	Year	Case No.	Mean Age, yr	Symptoms	Location	Size	Treatment	Outcomea	Complication	F/U Period, mo
1	Hawke et al. (10)	1987	1	68	N/A	Bilateral	N/A	none	N/A	None	N/A
2	Hawke et al. (11)	1988	1	58	Otorrhea	Right	N/A	none	N/A	None	N/A
3	Heffez et al. (12)	1989	2	60	Otalgia	Right (2)	42 mm, N/A	NSAID	Success	None	N/A
4	Weissman et al. (13)	1991	2	33	Otorrhea	Left (2)	N/A	Antibiotics, steroids Intermaxillary fixation	Partial success	None	N/A 12
5	Cecire et al. (14)	1991	1	60	Otorrhea, otalgia	Left	N/A	N/A, fascia	Success	None	N/A
6	Kryzer and Lambert (15)	1992	1	65	clicking tinnitus	Left	N/A	None	N/A	None	N/A
7	Ali and Rubinstein (16)	2000	1	64	HL	Right	N/A	N/A, fascia, steroid	Success	None	N/A
8	Anand et al. (17)	2000	2	49	Clicking tinnitus, otalgia	Left (2)	7.0 mm, 7.0 mm	Preauricular, medpor	Success	None	N/A
9	Moriyama, et al. (1)	2005	1	41	Clicking tinnitus	Right	3.0 mm	Endaural, cartilage	Success	None	60
10	Tan et al. (18)	2009	1	63	Otorrhea	Right	7.5 mm	Preauricular, cartilage	Success	Crepitus upon jaw movement	6
11	Ha et al. (8)	2010	1	76	Otalgia	Right	3 mm	TMJ physiotherapy	Partial success	none	N/A
12	Park, et al. (4)	2010	6	57	4 EF, clicking tinnitus, otorrhea, otalgia, HL	Right (2) Left (4)	1.0–10.0 mm	Endaural, skin graft (2) preauricular, titanium (4)	Success	None	6
13	Akcam et al. (19)	2011	1	48	Clicking tinnitus, facial pain	Left	5.0 mm	Preauricular, cartilage	Success	None	3
14	Ajduk et al. (20)	2012	1	53	Otorrhea	Right	4.0 mm	Preauricular, cartilage	Success	None	18
15	Nakasato et al. (21)	2013	1	61	Crunching sound	Right	16.0 mm	Preauricular, cartilage and TPF	Success	None	20
16	Kim et al. (22)	2013	1	53	Clicking tinnitus	Left	6.0 mm	Anxiolytics, muscle relaxant	Failure	None	N/A
17	Rana et al. (23)	2015	2	8	Otorrhea	Right (1) Left (1)	N/A	Preauricular, TPF	Success	None	12
18	Shapiro and Osborn (24)	2016	1	54	Otalgia	Left	5.0 mm	Preauricular, TPF	Success	None	6
19	Yoo et al. (7)	2016	2	57	Otalgia	Right (1) Left (1)	4.0–5.0 mm	Endaural, titanium	Success	None	12
20	Ryu et al. (25)	2017	1	46	Clicking tinnitus	Right	9.0 mm	Preauricular, titanium	Partial success	None	2
21	Singh et al. (26)	2017	1	35	Otorrhea, EF	Left	20.0 mm	Preauricular, collagen mesh	Success	None	12
22	Burlak et al. (27)	2018	1	52	Otorrhea	Left	3.5 mm	Postauricular, cartilage	Success	None	N/A

^aSuccess: successful reduction of TMJ herniation with symptom resolution; partial success: symptom resolution despite persistent TMJ herniation; failure: no change of symptoms and TMJ herniation; N/A: no treatment done.

EF indicates ear fullness; HL, hearing loss; NSAID, nonsteroidal anti-inflammatory drug; TMJ, temporomandibular joint; TPF, temporoparietal fascia.

Interestingly, all previous case reports focused on the effect of surgical EAC defect repair, understating the possible risks and complications of a surgical approach for the management of the symptoms. Not all reports disclosed detailed postoperative follow-up results, but the mean follow-up period for the published cases was approximately 9 months. Because the follow-up period falls short of 1 year postoperatively, there is a chance that delayed symptom recurrence and late-onset complications that occur a few years after the procedure may not have been considered. This raises the question of whether surgical reconstruction of the EAC is currently overvalued.

Unlike previous studies, we recommended annual follow-ups, even for those who immediately showed satisfactory symptom resolution. Although the initial surgery was successful in many cases, not all patients achieved complete symptom resolution after the first surgery. Primary repair is particularly difficult in cases with large EAC defects, and even with successful grafting, some patients experience persistent symptoms due to mild residual fluctuation. In such cases, revision surgery is inevitable, and posterior canalplasty is performed to secure EAC patency. Two patients experienced refractory postoperative infection, which eventually led to revision surgery to retrieve the titanium mesh and subsequent canal wall-down mastoidectomy or subtotal petrosectomy. Hence, it is impractical to standardize the surgical treatment of TMJ herniation to a single procedure of primary defect repair. We suggest that our stepwise approach to address TMJ herniation via an EAC wall defect be practiced.

When applying the stepwise approach, precaution is needed to determine which patients are indicated for revision surgery. Primary repair of the EAC wall defect cannot guarantee a completely solid EAC wall; thus, mild residual movement of the area during mastication is unavoidable. Although incessant, if the severity of symptoms improves after surgery and the degree of EAC wall fluctuation does not aggravate over time, observation is preferred over revision surgery. Nonetheless, if the graft material had migrated from its original position or if the combined infection had not subsided with pharmacologic management, the surgeon should not be hesitant to perform a secondary operation for exploration and possible retrieval of the dislodged graft material. Depending on the patient’s situation, reattempt of primary defect closure may be an option, wherein canalplasty by drilling the posterior EAC wall may be a preferable approach. If conventional canalplasty does not offer sufficient EAC width, canal wall-down mastoidectomy can be considered as a third-line treatment.

Our study has its limitations as it only involved 10 cases because of the low incidence of EAC anterior wall defects. Of the 10 patients, 3 patients who underwent primary repair via the endaural approach showed treatment failure, making a bias toward the preauricular approach. In addition, all 10 cases used a titanium mesh for reconstruction of the EAC defect; therefore, analysis of the differences among reconstruction materials used is also inapplicable. Furthermore, we lack long-term data for three cases in which the operation was conducted quite recently, within a year. Despite these limitations, our study is the first to report about the failure of primary EAC defect repair and to propose a stepwise approach for the treatment of TMJ herniation into the EAC. Future studies should focus on including more cases with diverse surgical approaches and reconstruction materials along with long-term follow-up data to enable a more comprehensive analysis.

CONCLUSIONS

Anterior wall defects of the EAC are rare, and a standard treatment has not yet been established. Here, we report a case series of patients who underwent surgery for TMJ herniation into the EAC and the long-term follow-up results. In our study, 3 of 10 cases showed recurrence and required further management. Therefore, patients with anterior wall defects of the EAC need long-term follow-up because of the possibility of recurrence or late-onset complications. Several different treatment methods should be applied according to the defect size and patient condition. Furthermore, we therefore suggest a creation of a treatment flowchart for such cases.