Effects of Cartilage Overlay on the Tympanic Membrane: Lessons From a Temporal Bone Study for Cartilage Tympanoplasty

Cartilaginous bending spring tympanoplasty: a temporal bone study and first clinical results

Objective

Anchoring grafts for tympanic membrane (TM) reconstruction in anterior and subtotal TM defects is essential to prevent medialisation and can be facilitated by cartilaginous bending spring tympanoplasty (CBST). The purpose of this study was to analyse the impact of spring cartilages on middle ear transfer functions and patient hearing levels.

Methods

In six fresh-frozen human temporal bones a cartilage graft (measuring 6 × 2 mm with a thickness of 0.1–0.2 mm) was formed into a ‘U’-shaped bending spring, to be placed between the medial tympanic wall and the tympanic underlay grafts. The stapes velocity for excitation by exponential sweeps from 400 to 10,000 Hz was measured with a laser Doppler vibrometer. The resulting middle ear transfer functions were compared with the reconstructed middle ear. For clinical evaluation, 23 ears in 21 patients with chronic otitis media and an intact ossicular chain were operated using CBST. At each follow-up visit, the patients underwent pure-tone audiometry and the Freiburg monosyllabic speech test at a presentation level of 65 dB SPL for the word recognition score (WRS).

Results

The measured stapes velocities at one-third octave midband frequencies averaged 3.56 × 10^–2 ± 9.46 × 10^–3 (mm/s/Pa) compared to 3.06 × 10^–2 ± 6.86 × 10^–3 (mm/s/Pa) with the bending and underlay cartilage in place (p = 0.319; r = 0.32). The bending spring tympanoplasty reduced the transfer function by 1.41 ± 0.98 dB on average. In the clinical part of the study, the graft success rate was 96% (22 out of 23 patients) after a mean follow-up of 5.8 ± 2.4 months (min. 3.5 months, max. 12.0 months). The air–bone gap improved significantly by 6.2 dB (± 6.6 dB; p < 0.001; r = 0.69), as well as the WRS from 61.8 ± 33.3% preoperatively to 80.0 ± 20.9% postoperatively (p = 0.031; r = 0.35).

Conclusion

Experimental data as well as initial clinical results suggest that CBST is an effective method for reconstructing anterior or subtotal defects of the tympanic membrane with satisfactory audiologic results and graft success rates comparable to previously described methods. It can, therefore, be added to the arsenal of tympanoplasty techniques for anterior and subtotal TM perforations.

Tympanoplasty Before Tympanoplasty: Alea Jacta Erat!

OBJECTIVES

Tympanoplasty is the most common ear surgery performed throughout the world. As its basic principles remain the same since its introduction, many publications usually explain, in the introduction, that tympanoplasty has been a successful technique since the 1950s. The aim of this historical notice is to go back to the origin of the word tympanoplasty, and its final introduction as a specific defined surgical concept.

MATERIAL AND METHOD

Historical study based solely on original publications in different languages.

RESULTS

The term tympanoplasty was first used by Hirch in 1912 for an operation for chronic adhesive catarrh of the middle ear. It was revived by Wullstein in 1952. One Polish, Miodonski, and three German otologists played an important role in the development of the actual concept and definition of tympanoplasty: Moritz, Zöllner and Wullstein, the two latter being recognized as worldwide dispensers of the technique.

CONCLUSION

The history of the term tympanoplasty can be divided into two periods: the first being 1912 to 1913 with its first use for an operation to treat chronic adhesive catarrh of the middle ear, and the second 1952 to 1955, with its revival and definitive implementation in the surgery of the ear based on the concept of protection of the round window and construction of an effective sound-transmitter system through the oval window. Nevertheless, the concept of tympanoplasty was already established in 1950 but not surgically definitively implemented: alea jacta erat-the die was cast!

Over-under cartilage tympanoplasty: technique, results and a call for improved reporting

OBJECTIVE

This study aimed to describe the microscopic over-under cartilage tympanoplasty technique, provide hearing results and detail clinically significant complications.

METHOD

This was a retrospective case series chart review study of over-under cartilage tympanoplasty procedures performed by the senior author between January 2015 and January 2019 at three tertiary care centres. Cases were excluded for previous or intra-operative cholesteatoma, if a mastoidectomy was performed during the procedure or if ossiculoplasty was performed. Hearing results and complications were obtained.

RESULTS

Sixty-eight tympanoplasty procedures met the inclusion criteria. The median age was 13 years (range, 3-71 years). The mean improvement in pure tone average was 6 dB (95 per cent confidence interval 4-9 dB; p < 0.0001). The overall perforation closure rate was 97 per cent (n = 66). Revision surgery was recommended for a total of 6 cases (9 per cent) including 2 post-operative perforations, 1 case of middle-ear cholesteatoma and 3 cases of external auditory canal scarring.

CONCLUSION

Over-under cartilage tympanoplasty is effective at improving clinically meaningful hearing with a low rate of post-operative complications.

Repair of subtotal tympanic membrane perforations: A temporal bone study of several tympanoplasty materials

The aim of this project was to investigate the effects of different types of graft material, and different remaining segments of the native TM on its motion. In twelve human temporal bones, controlled TM perforations were made to simulate three different conditions. (1) Central perforation leaving both annular and umbo rims of native TM. (2) Central perforation leaving only a malleal rim of native TM. (3) Central perforation leaving only an annular rim of native TM. Five different graft materials (1) perichondrium (2) silastic (3) thin cartilage (4) thick cartilage (5) Lotriderm^® cream were used to reconstruct each perforation condition. Umbo and stapes vibrations to acoustic stimuli from 250 to 6349 Hz were measured using a scanning laser Doppler vibrometer. Results showed that at low frequencies: in the Two Rims condition, all grafting materials except thick cartilage and Lotriderm cream showed no significant difference in umbo velocity from the Normal TM, while only Lotriderm cream showed a significant decrease in stapes velocity; in the Malleal Rim condition, all materials showed a significant decrease in both umbo and stapes velocities; in the Annular Rim condition, all grafting materials except Lotriderm and perichondrium showed no significant difference from the Normal TM in stapes velocity. Umbo data might not be reliable in some conditions because of coverage by the graft. At middle and high frequencies: all materials showed a significant difference from the Normal TM in both umbo and stapes velocities for all perforation conditions except in the Annular Rim condition, in which silastic and perichondrium showed no significant difference from the Normal TM at umbo velocity in the middle frequencies. In the low frequencies, the choice of repair material does not seem to have a large effect on sound transfer. Our data also suggests that the annular rim could be important for low frequency sound transfer.