|CASE IN POINT - CLINICS IN OTOLOGY
|Year : 2016 | Volume
| Issue : 3 | Page : 174-176
Post traumatic external auditory canal stenosis causing conductive hearing loss
Ashok Kumar, Aniruddha Sarkar, Shailendra Kumar
Department of Otolaryngology and Head and Neck Surgery, Dr. Ram Manohar Lohia Hospital, New Delhi, India
|Date of Web Publication||27-Feb-2017|
Dr. Aniruddha Sarkar
Department of Otolaryngology and Head and Neck Surgery, Dr. Ram Manohar Lohia Hospital, New Delhi
Source of Support: None, Conflict of Interest: None
Acquired external auditory canal stenosis is an uncommon entity which can arise from a number of different causes including infection, trauma, neoplasia, inflammation, and radiotherapy. Posttrauma stenosis is extremely rare; only 10% of stenosis is caused by trauma in many series. Patients generally suffer from conductive hearing loss. Surgery is the treatment of choice for posttraumatic canal stenosis. The main objective of the surgery is to produce a dry, patent ear canal by removing the stenotic segment, enlarging the bony canal, and performing wide meatoplasty. In this paper, we report a case of posttraumatic external auditory canal stenosis, following foreign body reaction which was entrapped in the canal during trauma, which was managed successfully 1 year after the trauma.
Keywords: Canalplasty, conductive hearing loss, external auditory canal, meatoplasty, stenosis
|How to cite this article:|
Kumar A, Sarkar A, Kumar S. Post traumatic external auditory canal stenosis causing conductive hearing loss. Astrocyte 2016;3:174-6
| Introduction|| |
Acquired external auditory canal (EAC) stenosis is not a common entity. It can be caused by infection, trauma, neoplasia, inflammation, and radiotherapy. Its incidence has been reported to be 0.6 cases per 100,000 inhabitants by the largest reported series of patients treated for EAC stenosis. Stenosis results in a blind, skin-lined canal just lateral to the tympanic membrane, which commonly presents as conductive hearing loss. This situation could either be caused by a congenital malformation of the EAC or may be acquired. The intervening segment between the medial aspect of the patent EAC and tympanic membrane usually consists of a fibrous plug. This entity has been referred to by several different terms including medial meatal fibrosis, EAC atresia, and medial canal or EAC stenosis., The most common cause of acquired EAC stenosis is chronic otitis externa, hence, most of the EAC stenosis cases presented in the literature are postinfectious, posttraumatic cases are extremely rare. Irrespective of the cause, stenosis of the EAC is a condition which is very difficult to manage, and recurrence rate is very high after treatment. Paparella and Kurkjain introduced the basic surgical principles of excising the fibrous plug, enlarging the cartilaginous and bony canal, and re-covering the canal; since then, modifications on this technique have been introduced primarily to prevent the most common postoperative complication, restenosis.
In this report, we present a case of posttraumatic EAC stenosis managed 1 year after the trauma.
| Case Report|| |
A 29-year-old male patient attended to our outpatient clinic with complaints of right-sided unilateral hearing loss for over 1 year. He had a history of a road traffic accident 1 year back. He realized mild hearing loss just after the trauma, and his hearing loss deteriorated gradually over a few days. His hearing loss stayed stable since then. He had history of right ear bleed after the trauma. He had no history of otorrhea or otalgia. On otoscopic examination, right EAC was found to be completely stenotic. The pure tone audiometry showed 40 dB conductive hearing loss in the right ear. High-resolution computerized tomography (CT) scan of the temporal bone showed soft tissue density lesion in the EAC with medial bulge of the tympanic membrane [Figure 1]. No cholesteatoma was seen in the CT scan, and the middle ear cavity and ossicles appeared to be normal. Surgery was planned to remove the stenotic segment of the EAC, to enlarge the bony ear canal, and to recreate an epithelial-lined EAC with a split thickness graft. Preoperatively, right EAC stenosis was present at the opening of the EAC, rest of the canal was found to be intact and filled with debris in the entire canal up to the tympanic membrane, which was later found to be intact. A post-aural approach was used to enter the canal wall, debris was removed, and wide meatoplasty was done. Following this, we harvested split thickness skin graft from the retroauricular region and placed it on the denuded bony EAC. The graft was stabilized with small wedges of silicone rubber (Silastic sponge). These sponges were removed 3 weeks after the surgery. The patient was followed up for 1 year. Right ear air bone conduction gap became normal and the canal remained patent, as shown in [Figure 2].
|Figure 2: Postoperative 12th month view of the patent external ear canal.|
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| Discussion|| |
EAC stenosis can be congenital or acquired. The most common cause of acquired EAC stenosis is otitis externa. Chronic inflammation of the EAC results in subepithelial infiltration of inflammatory cells; this inflammatory process results in fibrotic changes to the canal, leading to EAC stenosis. Trauma is another possible cause of EAC stenosis. Iatrogenic trauma from prior otologic surgery is a common inciting event, however, direct trauma to EAC is a rare cause of stenosis. In one of the largest series on this subject, there was only one acquired EAC stenosis due to previous trauma in a total of 49 patients. Selesnick et al. reviewed 15 reports on this topic and reported that chronic infection was the leading cause of this disorder in 54.1% of the patients, followed by postsurgical (20.2%) and traumatic (11%) causes. Acquired stenosis can be treated medically or surgically, however, medical management plays a limited role in the treatment of posttraumatic stenosis since the goal of medical therapy is to control the underlying infection and prevent the formation of granulation tissue. Surgery should be the treatment of choice in posttraumatic EAC stenosis. The goal of the surgery is to remove the fibrous plug/debris, widen the bony EAC, expose the tympanic membrane, and recreate an epithelial-lined EAC. Published recurrence rates range from 6% to 27% in different studies, with 100% in patients where only the fibrous plug is removed. An important component of EAC stenosis repair following resection of the fibrous plug is a canalplasty, and if necessary, meatoplasty. Although recurrence of EAC stenosis has been documented up to 9 years after surgery, majority of restenosis cases occur after the first operative year., In our case, we removed the debris plugging the canal completely and performed wide meatoplasty. No restenosis occurred even after 1 year of follow up.
| Conclusion|| |
Acquired external auditory stenosis is a very rare cause of conductive hearing loss, and direct trauma to external ear can cause this condition. Complete resection of fibrous plug with canalplasty and re-epithelization of EAC with split skin thickness skin grafts should be the treatments of choice to achieve a patent EAC for a long period of time.
This article does not contain any studies with animals performed by any of the authors. All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from the participants included in the study.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]