Beware of a Fragile Footplate: Lessons from Ossiculoplasty in Patients with Ossicular Anomalies Related to Second Pharyngeal Arch Defects.

Sun A Han,Ja-Won Koo,Byung Yoon Choi,Goun Choe,Jae-Jin Song,Yoonjoong Kim

doi:10.3390/jcm8122130

Abstract

Background and objectives: We review the intraoperative findings and postoperative outcomes of ossiculoplasty in subjects with second pharyngeal arch (SPA)-derived ossicular anomalies. We summarize potential intraoperative complications and recommend precautions that may reduce the risk of fracture. Materials and Methods: Twenty-four patients with SPA-derived ossicular anomalies were included, and pre- and postoperative audiometric results were compared. Results: The mean air conduction threshold (56.0 ± 12.4 dB HL) was significantly improved 1 month (27.6 ± 10.1 dB HL) and 6 months (23.8 ± 13.2 dB HL) after surgery (p < 0.001). The preoperative air–bone gap (ABG) (40.4 ± 7.4 dB HL) was significantly decreased at 1 month (15.1 ± 5.9 dB HL) and 6 months (11.3 ± 8.9 dB HL) postoperation. ABG closure was successful (<20 dB HL) in 21 (87.5%) patients 6 months after surgery. Intraoperative footplate fractures occurred in 3 of 24 patients. The fractures were managed successfully, and the ABG closure was successful in all cases. Conclusions: The stapes footplate is likely to be relatively thin in subjects with SPA-derived ossicular anomalies because the footplate is partially or totally derived from the SPA. Thus, a fragile footplate should be expected, and care is needed when handling the footplate. However, when complications are overcome, the audiological outcomes are excellent in most cases.

Highlights

A congenital ossicular anomaly should be suspected when a patient presents with nonprogressive conductive hearing loss with a normal tympanic membrane and no history of infection or trauma.Embryological studies of the development of the middle ear ossicles have shown that the head of the malleus and the body and short process of the incus are derived from the first pharyngeal arch, while the handle of the malleus, the long process of the incus, and the stapes suprastructure are derived from the second pharyngeal arch [1] (Figure 1A)
Studies showed that the labyrinthine portion of the stapes footplate is derived from the mesenchyme of the otic capsule, while the lateral portion is derived from the second pharyngeal arch [1,2,3,4] (Figure 1B)
We described three cases of intraoperative iatrogenic footplate and the patients with ossicular anomalies attributable to abnormal development of the second fracture pharyngeal postoperative outcomes

Summary

Introduction

A congenital ossicular anomaly should be suspected when a patient presents with nonprogressive conductive hearing loss with a normal tympanic membrane and no history of infection or trauma.Embryological studies of the development of the middle ear ossicles have shown that the head of the malleus and the body and short process of the incus are derived from the first pharyngeal arch, while the handle of the malleus, the long process of the incus, and the stapes suprastructure (the head and crus) are derived from the second pharyngeal arch [1] (Figure 1A). Studies showed that the labyrinthine portion (medial half) of the stapes footplate is derived from the mesenchyme of the otic capsule, while the lateral portion is derived from the second pharyngeal arch [1,2,3,4] (Figure 1B). Recent contradictory evidence suggests that the footplate develops independently of the otic capsule, being derived solely from the second pharyngeal arch [5,6] (Figure 1C). We review the intraoperative findings and postoperative outcomes of ossiculoplasty in subjects with second pharyngeal arch (SPA)-derived ossicular anomalies. Materials and Methods: Twenty-four patients with SPA-derived ossicular anomalies were included, and pre- and postoperative audiometric results were compared. The preoperative air–bone gap (ABG) (40.4 ± 7.4 dB HL) was significantly decreased at 1 month (15.1 ± 5.9 dB HL).

Methods

Discussion

Conclusion