Long-Term Audiometric and Clinical Outcomes Following Stapedectomy With the Shape Memory Nitinol Stapes Prosthesis

Abstract

Objective: To assess long-term hearing outcomes following stapedectomy using a self-crimping shape memory nitinol prosthesis. The results were compared with those of a group of patients who received a conventional prosthesis. Study Design: Retrospective case review. Setting: Tertiary referral center. Patients: All patients who underwent stapedectomy for otosclerosis between July 2001 and November 2008 with a minimum dataset of preoperative, early postoperative (≤2 yr), and late postoperative (≥6 yr) audiometry were included. Fifty-six patients with a nitinol prosthesis and 27 patients with a titanium prosthesis met the inclusion criteria. Intervention: Stapedectomy using a nitinol or conventional prosthesis. Main Outcome Measure(s): Hearing outcomes by audiological assessment. Results: Mean duration of follow up was 9.5 (standard deviation [SD] 1.4) years in the nitinol group and 12.6 (SD 2.1) years in the titanium group. The early and late mean postoperative air-bone gaps (ABGs) were 9.7 and 9.8 dB in the nitinol group and 11.0 and 12.6 dB in the titanium group, respectively. The proportion of patients achieving an ABG less than or equal to 20 dB at early and late follow up was 96% and 96% in the nitinol group and 92% and 86% in the titanium group respectively. Conclusions: The excellent closure of the ABG achieved at early follow up remains remarkably stable up to 12 years using a self-crimping shape memory nitinol prosthesis. There is no evidence that firm fixation of the hook around the long process of incus has a detrimental effect in the long-term.

Rates of Sensorineural Hearing Loss and Revision Surgery After Stapedotomy: A Single-institution Experience Using the Nitinol Prosthesis

“…When considering only primary stapedotomies performed by surgeons at our institution in the last 20 years, we found a 4.49% revision rate. This is comparable to a recent study by Heywood et al ( 31 ), which demonstrated a revision rate of 4.5% in stapedotomies performed between 2001 and 2008 using the shape memory Nitinol prosthesis, as was employed in all procedures in our series. These numbers are in contrast to other large, historic case series that have demonstrated higher proportions of patients requiring revision stapedotomy, ranging from 2.6 to 29.4% ( 20 , 31 – 34 , 36 – 39 ).…”

“…This is comparable to a recent study by Heywood et al ( 31 ), which demonstrated a revision rate of 4.5% in stapedotomies performed between 2001 and 2008 using the shape memory Nitinol prosthesis, as was employed in all procedures in our series. These numbers are in contrast to other large, historic case series that have demonstrated higher proportions of patients requiring revision stapedotomy, ranging from 2.6 to 29.4% ( 20 , 31 – 34 , 36 – 39 ). Interpretation of these numbers must be guarded, though, given the risks of: 1) revision surgeries being performed at longer intervals than those captured in our study, and 2) factors such as patient relocation, insurance coverage, or preferences leading them to undergo revision at institutions other than our own.…”

“…“Success” of stapedotomy is often defined as closure of the air-bone gap (ABG) to within 10 decibels hearing level (dB HL), and the rate in the literature by this definition is up to 94% ( 20 ). The need for revision stapedotomy has historically been quoted to patients as occurring in 5%–10% of cases, although several large case series have cited higher rates of up to 20%–30% ( 31 – 39 ).…”

Long-Term Audiometric Outcomes of a Self-Crimping Stapes Prosthesis With CO2 Laser Stapedotomy

“…To address that, prostheses that do not require crimping have been introduced, including the classic bucket handle prosthesis and its modifications. More recently, nitinol-based prostheses that assume a predetermined shape once heated, for example with bipolar cautery, CO 2 laser, or a heat applicator, have been introduced, and have been shown to be safe and effective (8)(9)(10).…”