Acquired stenosis of the external auditory canal - long-term results and patient satisfaction

Treatment of external auditory canal stenosis and atresia after transcanal endoscopic ear surgery

PURPOSE

To discuss the treatment of external auditory canal stenosis or atresia occurring as a complication of transcanal endoscopic ear surgery.

MATERIALS AND METHODS

We retrospectively analyzed the medical records of 11 patients who developed external auditory canal stenosis or atresia after undergoing transcanal endoscopic ear surgery. The 10 patients with stenosis were treated with external auditory canal expansion via drainage tube insertion; 2 of these patients further received local injections of triamcinolone acetonide. One patient with atresia was treated with meatoplasty surgery followed by tube insertion and triamcinolone acetonide injection.

RESULTS

The stenosis/atresia improved in all patients, and the external auditory canal was unobstructed without restenosis.

CONCLUSIONS

Stenosis/atresia of the external auditory canal after transcanal endoscopic ear surgery should be treated with dilation therapy/meatoplasty in a timely manner to prevent progressive hyperplasia of the scar and regain a normal-sized ear canal.

Lateral Stenosis of External Auditory Canal Secondary to Corrosive acid Injury: A Rare Case Report and Review of Literature

Acquired external auditory canal (EAC) stenosis is an uncommon condition with an incidence of 0.6 in 100,000 population. Road traffic accidents and otology surgeries are the frequently reported causes for it to occur. The high rate of restenosis makes this condition difficult to manage. A 50 year old lady presented with history of accidental instillation of acid in her left ear at 6 months of age by the care giver. The patient developed stenosis of left EAC with hearing loss. Examination revealed pin point stenosis of left EAC. Puretone audiogram revealed a moderately severe conductive hearing loss. Computed tomogram showed soft tissue lesion obliterating the entire EAC and extending into the middle ear and antrum. Intra operatively only the cartilaginous EAC was stenosed. Surgical excision of the fibrotic scar with a tympanomastoidectomy and wide meatoplasty was done. Regular post operative aural toileting, packing with merocele strips and application of topical antibiotic -steroid preparations was done. 6 months post-surgery a patent EAC and healed tympanic membrane was achieved. In this report, we present a rare case of lateral EAC stenosis secondary to corrosive acid injury, highlighting the surgical steps, post operative care and surgical outcomes. A limited review of literature is also presented.

Rat Model of External Auditory Canal Stenosis

HYPOTHESIS

Circumferential electrocautery injury of the rat external auditory canal (EAC) can induce a reproducible animal model of acquired stenosis.

BACKGROUND

Acquired EAC stenosis may occur as a result of chronic inflammation or trauma to the EAC skin and is characterized by narrowing of the EAC, retention of debris, and hearing loss. Treatment is surgery but it is often complicated by restenosis. A reliable and inexpensive animal model of EAC stenosis has not been described. There have been no studies correlating the extent of EAC injury with the extent of stenosis.

METHODS

Rats received a 25, 50, or 75% circumferential EAC injury with electrocautery. The extent of resulting stenosis was quantified 21 days following injury. The nature of the injury and healing response was assessed with histology.

RESULTS

A 25% circumferential injury led to 4 to 34% stenosis (mean, 13%), 50% injury resulted in 43 to 100% stenosis (mean, 73%), and 75% injury resulted in 94 to 100% stenosis (mean=99%, p < 0.0001). The 50% circumferential injury produced 30 to 75% stenosis in five of eight ears, the remainder had >75% stenosis. Wounded ears showed evidence of intact cartilage and epithelium, with increased thickness of the subepithelial layer and localized fibrosis.

CONCLUSIONS

Electrocautery injury in the ventral aspect of the rat EAC resulted in reproducible EAC stenosis. This rat model may be useful in studying therapy to prevent acquired EAC stenosis due to acute injury. The correlation of the extent of injury (circumference) with resulting stenosis may inform clinical management of EAC injuries.

Modified meatotympanoplasty for external auditory canal stenosis and lateralized tympanic membrane: a preliminary study

Background: The surgical treatment of external auditory canal stenosis (EACS) and lateralized tympanic membrane (LTM) is challenging because there is a high risk of postoperative complications.Objectives: The aim of this study was to evaluate the postoperative hearing levels and other outcomes of 10 cases with EACS and LTM.Materials and methods: This was a retrospective preliminary study of patients with EACS and LTM who underwent meatotympanoplasty from 2008 to 2018. Their mean age at surgery was 31.6 years. The surgeries were performed taking into consideration the following: (1) creating a large EAC and functioning tympanic membrane (TM) and (2) avoiding complete mastoidectomy to prevent postoperative cavity problems.Results: The mean follow-up period was 3 years 10 months. The average preoperative and postoperative air-bone gaps (ABGs) were 40.4 dB and 23.0 dB, respectively, and there was a significant difference. A postoperative ABG less than 30 dB was achieved in 80% (8/10) of patients. Four cases had postoperative complications (re-stenosis of the EAC and/or re-lateralization of the TM).Conclusions and significance: The postoperative results presented were comparable to those of previous surgical techniques; however, further development is needed to prevent postoperative complications and earn better hearing results.

Healing acceleration of mastoidectomy through the external auditory canal incisionless approach

PURPOSE

To evaluate a surgical procedure of canal wall-up mastoidectomy without incision of the canal which enables accelerated healing and enhances hearing outcome.

METHODS

A total of 79 patients were enrolled. A canal-incisionless technique was used in 37 patients undergoing canal wall-up/down mastoidectomy (CWU/DM), explo-mastoidectomy, and cochlea implantation as staged operation after obliteration of the mastoid, and canal incision was used in the remaining 42 patients as comparison group.

RESULTS

Preoperative and postoperative pure tone audiometry/word recognition score and postoperative status including the healing time and complications were analyzed. Healing time of the canal-incisionless procedure (2.7 weeks) was shorter than that of conventional mastoidectomy with canal incision (5.7 weeks). Complication rate of the canal-incisionless procedure was lower than that of canal incision approach, even though statistical meaningless.

CONCLUSION

Despite the small sample size of our study, in patients undergoing CWDM, explo-mastoidectomy, and cochlea implantation, more acceptable healing was achieved using the canal-incisionless technique than with the canal incision technique. CWU/DM without canal incision is useful to achieve optimal surgical view, eliminate pathology of the middle ear, and accelerate healing time.