Surgical Management for Dysplastic or Congenitally Absent Oval Window

Audiologic Outcomes After Vestibulotomy in Patients With Congenital Absence of the Oval Window

OBJECTIVE

To examine the clinical features and surgical outcomes in patients with congenital absence of the oval window (CAOW), and to investigate the potential factors that affect audiologic results.

STUDY DESIGN

A retrospective chart review.

SETTING

A tertiary academic center.

PATIENTS AND INTERVENTION

A total of 17 ears among 16 patients were confirmed to have CAOW. Among them, 13 ears underwent vestibulotomy for hearing reconstruction. Clinical parameters associated with the hearing outcomes were analyzed.

MAIN OUTCOME MEASURES

A mean air-bone gap (ABG) after 6-month and long-term follow-up was compared with preoperative measurements.

RESULTS

Intraoperative findings showed that anomalies of the malleus or incus were observed in 11 ears (64.7%), stapes anomalies were present in all ears (100%), and facial nerve anomalies were present in 10 ears (58.8%). Because of unfavorable facial nerve anomalies, hearing reconstruction was aborted in four cases (23.5%). In the hearing reconstruction group, the mean ABG at 6 months postoperation was significantly reduced after compared with the preoperative value (44.0 ± 8.4 dB versus 58.8 ± 9.1 dB, p = 0.006). After dividing ears into a success subgroup (ABG ≤ 30 dB, seven ears) and non-success subgroup (ABG > 30 dB, six ears), the use of a drill during vestibulotomy was significantly related to a poor hearing outcome (100% versus 16.7%, p = 0.015). The long-term follow-up result (mean, 60 mo) revealed no deterioration compared with the 6-month postoperative result. Five ears (29.4%) underwent revision surgery, and three of them showed ABG improvements. No serious complications were reported.

CONCLUSION

Vestibulotomy is an effective and safe option for hearing restoration in patients with CAOW, particularly when the use of a drill is not required. The long-term audiologic outcome is also reliable.

Surgical outcome in class 4 congenital anomalies of the ossicular chain: a systematic review of the literature

OBJECTIVE

To review hearing and surgical outcomes after reconstructive middle ear surgery in class 4 congenital middle ear anomalies (CMEA), e.g., patients with oval- or round window atresia of dysplasia.

DATA SOURCES

Pubmed/Medline, Embase and Cochrane library.

REVIEW METHODS

Articles containing data on hearing outcomes and complications after reconstructive ear surgery in class 4 anomalies were analyzed and critically appraised. The following data were included and reviewed: patient demographics, audiometric testing, surgical techniques, complications, revision surgeries and their outcomes. Risk of bias was determined, and GRADE certainty of evidence was assessed. Primary outcomes were postoperative air conduction thresholds (AC), change in AC, and success rates (closure of the ABG to within 20 dB), the occurrence of complications (most importantly sensorineural hearing loss) and the long-term stability of hearing results (> 6-month follow-up) and occurrence of recurrence of preoperative hearing loss.

RESULTS

Success rates varied from 12.5 to 75% at long-term follow-up with larger cohorts reporting success rates around 50%, mean postoperative gain in AC varied from 4.7 to 30 dB and - 8.6 to 23.6 dB at, respectively, short- and long-term follow-up. No postoperative change in hearing occurred in 0-33.3% of ears, and recurrence of hearing loss occurred in 0-66.7% of ears. SNHL occurred in a total of seven ears across all studies of which three experienced complete hearing loss.

CONCLUSION

Reconstructive surgery can be an effective treatment option which should be considered in patients with very favorable baseline parameters, while also considering the substantial risk of recurrence of hearing loss, the possibility of unchanged hearing despite surgery and the rare occurrence of SNHL.

LEVEL OF EVIDENCE

2c.

Anatomic features of the fetal round and oval windows, and their relations with the tympanic nerve

OBJECTIVE

The study aimed to examine morphometric properties of the round window (RW) and oval window (OW) and to show their relation with the tympanic nerve (the Jacobson's nerve, JN) in human fetuses from the otologic surgeon's perspective.

METHODS

Thirty temporal bones of 15 fetal cadavers (8 males, 7 females) aged with 24.40 ± 3.71 weeks were included in the study. The height, width and surface area of the RW and OW and also distance from the JN to the OW and RW were measured.

RESULTS

The height, width and surface area of the RW in this work were measured as 1.48 ± 0.25 mm, 1.57 ± 0.37 mm, and 2.05 ± 0.69 mm², respectively. The RW was detected as round-shaped (8 cases, 26.7%), oval-shaped (15 cases, 50%), and dome-shaped (7 cases, 23.3%). The height, width and surface area of the OW were measured as 1.42 ± 0.26 mm, 2.90 ± 0.44 mm, and 3.63 ± 0.74 mm², respectively. The OW was observed as oval-shaped (15 cases, 50%), kidney-shaped (10 cases, 33.3%), D-shaped (4 cases, 13.3%), and trapezoid-shaped (1 case, 3.3%). The JN was found 1.21 ± 0.60 and 1.18 ± 0.54 mm away from the RW and OW, respectively.

CONCLUSION

This study containing morphological data about the shapes, diameters and area of the RW and OW may be useful to predict surgical difficulty, and to select implants of suitable size preoperatively for the windows. Knowing the relationship between the JN and the windows can be helpful to avoid iatrogenic injuries of the nerve.