Audiologic and Surgical Outcomes in Endoscopic Revision Stapes Surgery

Main Point

This case series describes the presentation, clinical course, and outcomes of six patients who underwent endoscopic revision stapes surgery. The results suggest that endoscopic revision stapes surgery is feasible and may provide a platform for a larger study to validate the efficacy of this approach with long-term outcomes. 

Introduction

When compared to primary stapes surgery, revision stapes surgery has been reported to result in less favorable surgical and audiologic outcomes, with an increased risk of postoperative sensorineural hearing loss (SNHL) (Otol Neurotol. 2010;31:875–882). Due to the presence of altered anatomy, adhesions, and a previously manipulated oval window, revision stapes surgery is technically challenging. Prior studies have shown that the most common causes of failure after primary stapes surgery include prosthesis dislocation, short or long prosthesis, incus erosion or dislocation, perilymphatic fistula, and ankylosis of the lateral ossicular chain (Otol Neurotol. 2010;31:875–882. Otol Neurotol. 2011;32:373–383. Otol Neurotol. 2009;30:1092–1100. Otol Neurotol. 2006;27(suppl 2):S25–S47) The success of revision stapes surgery relies on intraoperative identification of the cause for initial surgical failure because a lack of diagnosis has been correlated with negative outcomes (Laryngoscope. 2018;128:2390–2396). Consequently, adequate visualization and evaluation of the ossicular chain and oval window are essential to accurately diagnose and treat the cause of failure.

An endoscopic approach to stapes surgery allows for enhanced visualization of the ossicular chain and oval window (Otol Neurotol. 2016;37:362–366. Laryngoscope. 2014;124:266–271. Otolaryngol Clin North Am. 2016;49:1215–1225. Otol Neurotol. 2018;39:1095–1101). Additionally, endoscopy of the middle ear has been especially useful in diagnosing ossicular malformations (Eur Arch Otorhinolaryngol. 2016;273:1723–1729), perilymphatic fistulas (Acta Otolaryngol Suppl. 1994;514:63–65), and ossicular fixation (Int J Pediatr Otorhinolaryngol. 2017;96:21–24. Otol Neurotol. 2016;37:1071–1076).

Although prior studies have demonstrated similar audiologic and surgical outcomes between endoscopic and microscopic approaches for primary stapes surgery (Laryngoscope. 2014;124:266–271. Otol Neurotol. 2017;38:662–666. Otolaryngol Head Neck Surg. 2016;154:1093–1098), endoscopic outcomes for revision stapes surgery have not been previously reported. This case series describes the presentation, clinical course, and outcomes of six patients who underwent endoscopic revision stapes surgery. 

Preoperative Demographics and Intraoperative Findings

Patient	Age	Sex	Ear	Prior Stapes Surgery (n)	Preoperative CT Findings	Intraoperative Findings	Intervention	Prosthesis	Postoperative Complications
1	47	F	L	1	Displaced prosthesis	Displaced prosthesis	Laser stapedotomy, longer prosthesis	Nitinol piston	-
2	63	F	L	1	-	Missing prosthesis, Incus necrosis	Laser stapedotomy, longer prosthesis	Nitinol piston (malleus to fenestra)	-
3	82	F	L	1	Normal prosthesis positioning	Displaced prosthesis, prolapsed facial nerve	Laser stapedotomy, longer prosthesis	Nitinol piston	Temporary dysgeusia
4	19	F	L	1	-	Short prosthesis without incus contact	Laser stapedotomy, longer prosthesis	Nitinol piston	-
5	57	M	R	3	-	Displaced prosthesis, malleus fixation, incus necrosis	Laser stapedectomy, longer prosthesis	Titanium bucket handle	-
6	51	M	L	1	Displaced prosthesis only	Displaced prosthesis, oval and round window otosclerosis	Stapedectomy, oval window drill-out	Titanium bucket handle	Labyrinthitis resolved with steroids
CT = computed tomography; F = female; L = left.

CT = computed tomography; F = female; L = left.

Methods

Following institutional review board (IRB) approval (IRB 171214, 022012-060.2), a retrospective chart review was performed of all adult patients who underwent endoscopic stapes surgery at two tertiary care otologic centers between 2014 and 2017. Patients who had a history of prior stapes surgery who underwent totally endoscopic revision stapes surgery were included in the study (three patients from each institution).

Patient demographics, clinical course, and audiologic data—including unaided air conduction thresholds, bone conduction (BC) thresholds, and speech discrimination scores—were recorded from the medical record. For each case, the cause of surgical failure was identified intraoperatively. Postoperative outcome variables included postoperative complications, prosthesis extrusion, dysgeusia, and tympanic membrane (TM) retraction or perforation. All patients had preoperative and at least six weeks of postoperative audiologic data. Audiometric testing and calculations were conducted as previously described (Otolaryngol Head Neck Surg. 2016;154:1093–1098). Audiometric data herein are presented according to the 1995 American Academy of Otolaryngology–Head and Neck Surgery consensus guidelines. Postoperative SNHL was defined as an increase in average unaided BC thresholds (at 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz) > 15 dB HL.4