This article provides step-by-step instructions for EEO. There are various techniques, types of grafts, and prostheses to reconstruct the ossicular chain10,11. Depending on the presence or absence of the stapes suprastructure, a PORP or TORP is required. The use of an endoscope allows for detailed visualization and assessment of the ossicular chain and its functionality. Even in difficult anatomical conditions, the endoscope provides an optimal view of the oval window and stapes suprastructure or footplate to position the graft with great precision. Postauricular incision and mastoidectomy can often be avoided27. Moreover, it is an excellent tool for educating inexperienced surgeons in both anatomical and surgical aspects28.
Recently published literature has demonstrated comparable audiologic outcomes between endoscopic and microscopic OPL27,29. Das et al. reported significantly improved closure of the ABG after one month with endoscopic PORP OPL, but long-term audiologic outcomes showed no statistically significant difference from the microscopic technique4. A systematic review published by Tsetsos et al. also showed comparable audiologic results for both microscopic and endoscopic techniques15. They also observed a trend toward shorter operative time and lower morbidity, such as postoperative pain and wound infections, with the endoscopic method. The data analysis of the pre- and postoperative audiometric evaluation showed an average ABG of 30.46 dB and 21.41 dB, respectively. There was a statistically significant improvement in ABG completion of 9.05 dB ± 14.72 dB between the preoperative and postoperative ABG (p < 0.01). The publication by Soloperto et al. showed comparable results with a mean ABG closure of 7.85 dB HL (p < 0.01) in patients undergoing autologous graft reconstruction16.
Several authors compared synthetic prostheses, particularly titanium prostheses, and autologous grafts in terms of hearing outcome and complications. Aminth et al. conducted a prospective study comparing an incus autograft to a titanium PORP and found significantly better hearing outcomes and graft uptake in the incus group30. In addition, postoperative complications such as prosthesis extrusion and residual TM perforation occurred more frequently in the titanium PORP group.
OPL performed with a DCB graft was found to offer even greater advantages in reducing the risk of prosthesis displacement or fixation compared with the use of an incus autograft31. In the field of autologous grafts, different options, such as the DCB graft and the malleus allograft, have shown comparable audiological results. Both options have restored the ABG to less than 20 dB in 81% of patients25,32. The use of a patient's own tissue minimizes the risk of implant rejection or extrusion of the prosthesis through the TM, leading to enhanced biocompatibility and reduced postoperative complications15. However, autologous materials do present certain drawbacks. These include longer surgical durations required for the remodeling process, the potential for retaining microscopic pieces of cholesteatoma, and availability limitations depending on the condition of the ossicular chain13,14. A single case of prosthesis extrusion (5%) was recorded in a cohort of 20 synthetic prostheses. No cases of extrusion occurred when autologous materials were used.
COM, with or without cholesteatoma, is the most frequent cause of ossicular chain disruption. In the total 60 cases, COM accounted for 55 (91.7%) cases, and a total of 38 patients (63.3%) showed histologically confirmed cholesteatoma. There is still a debate about the most appropriate timing for ossicular chain reconstruction. In cases of single-stage OPL, endoscopic reconstruction of the ossicular chain is performed at the same time as COM surgery. If residual disease is a potential problem, ossicular chain reconstruction may be deferred to a later procedure, usually scheduled 12 to 18 months after the initial surgery and referred to as a second OPL. In this study, a uniform approach with single-stage surgery was adopted across the cohort to achieve early hearing recovery. However, in scenarios where the disease affects the stapes footplate, it may be appropriate to consider second-stage OPL. Both single-stage and second-stage OPL seem to achieve similar hearing outcomes16.
The long process of the incus is the most vulnerable part for necrosis secondary to both trauma and infections33. In cases with exclusive erosion of the incus long process, rebridging of the ossicular gap with bone cement offers a valid alternative to the OPL procedures presented in this article. Several authors reported comparable long-term audiological outcomes associated with this technique34,35.
The limited sample size of this study and the relatively short FU period prevent robust statistical results and a comprehensive evaluation of the long-term results of the individual OPL techniques. Furthermore, parametric statistical analysis of small subgroups might lead to overestimation or misleading conclusions. The predominant focus on cases of COM limits the generalizability of the results to other middle-ear pathologies. The inclusion of multiple revision cases presents a particular challenge and may not fully represent the primary surgical outcomes.
In conclusion, EEO is a valid surgical option for ossicular chain reconstruction with autologous or synthetic material. It is a safe and minimally invasive procedure with acceptable hearing restoration.