10.14639/0392-100X-N1933
Objective. To investigate whether patients with conductive hearing loss (CHL) and normal preoperative investigations may benefit from exploratory tympanotomy (ET) and tailored treatment performed according to intraoperative findings.Methods. Patients treated with ET for CHL with normal pre-operative otoscopy, tympanometry and CT scan from 2011 to 2019 were reviewed. Data regarding demographics, audiometry, intraoperative findings and surgery were collected and analysed to assess if they can predict post-operative air bone gap (ABG) closure and patient satisfaction.Results. Forty-eight cases were included. Mean ABG significantly reduced (p &lt; 0.001) from preoperative (38.4 dB) to postoperative (14.8 dB). Post-operative ABG closure within 10 dB was observed in 20 cases (41.7%). Overall satisfaction was reported in 60% of cases. Stapes fixation was the most common diagnosis (47.9%) and significantly associated with lower post-operative ABG and higher satisfaction.Conclusions. In CHL with normal pre-operative investigations, ET represents the mainstay of treatment, even if audiological outcomes may widely vary. Intraoperative finding of stapes fixation (thus stapedotomy) ensures the best audiological and satisfaction outcomes.
text/xml
1827-675X
1933
en
Tommaso Sorrentino
http://creativecommons.org/licenses/by-nc-nd/4.0
ACTA Otorhinolaryngologica Italica
ossicular replacement
Exploratory tympanotomy in conductive hearing loss with normal pre-operative investigations
Text.Serial.Journal
https://www.actaitalica.it/
42
Otology
2022-12-29
2021-11-23
2022-12-29
2023-01-16
569-581
1
Tommaso Sorrentino
2022/12/29
10.14639/0392-100X-N1933
569
Department of Otolaryngology-Head and Neck Surgery, ASST Spedali Civili, University of Brescia, Brescia, Italy
1827-675X
ossicular replacement
en
581
Exploratory tympanotomy in conductive hearing loss with normal pre-operative investigations
https://www.actaitalica.it/article/download/1933/897
42
ACTA OTORHINOLARYNGOLOGICA ITALICA 2022;42:569-581; doi: 10.14639/0392-100X-N1933




Otology


Exploratory tympanotomy in conductive hearing loss
with normal pre-operative investigations
La timpanotomia esplorativa nelle ipoacusie trasmissive con esami pre-operatori normali
Michele Tomasoni1, Daniele Borsetto2, Alessandra Deretti1, Mara Arcuri1, Alessandra Sordi1, Silvia Zorzi1,
Luca Oscar Redaelli de Zinis1,3, Cesare Piazza1, Alberto Deganello1, Tommaso Sorrentino1
1
 Department of Otolaryngology-Head and Neck Surgery, ASST Spedali Civili, University of Brescia, Brescia, Italy; 2 Department
of ENT Surgery, Cambridge University Hospitals, Cambridge, UK; 3 Department of Pediatric Otolaryngology-Head Neck Surgery,
Children Hospital ASST Spedali Civili, University of Brescia, Brescia, Italy


SUMMARY
Objective. To investigate whether patients with conductive hearing loss (CHL) and normal
preoperative investigations may benefit from exploratory tympanotomy (ET) and tailored
treatment performed according to intraoperative findings.
Methods. Patients treated with ET for CHL with normal pre-operative otoscopy, tympa-
nometry and CT scan from 2011 to 2019 were reviewed. Data regarding demographics,
audiometry, intraoperative findings and surgery were collected and analysed to assess if
they can predict post-operative air bone gap (ABG) closure and patient satisfaction.
Results. Forty-eight cases were included. Mean ABG significantly reduced (p < 0.001)
from preoperative (38.4 dB) to postoperative (14.8 dB). Post-operative ABG closure within
10 dB was observed in 20 cases (41.7%). Overall satisfaction was reported in 60% of cases.
Stapes fixation was the most common diagnosis (47.9%) and significantly associated with
lower post-operative ABG and higher satisfaction.
Conclusions. In CHL with normal pre-operative investigations, ET represents the mainstay
of treatment, even if audiological outcomes may widely vary. Intraoperative finding of sta-
pes fixation (thus stapedotomy) ensures the best audiological and satisfaction outcomes.
KEY WORDS: hearing loss, conductive, exploratory tympanotomy, otosclerosis, stapes
surgery, ossicular replacement                                                                     Received: November 23, 2021
                                                                                                   Accepted: July 6, 2022

RIASSUNTO                                                                                          Correspondence
Obiettivo. Studio dell’outcome audiologico nei pazienti con ipoacusia trasmissiva (CHL) e          Michele Tomasoni
indagini preoperatorie normali trattati con timpanotomia esplorativa (ET).                         Department of Otorhinolaryngology-Head and
Metodi. È stata condotta una revisione dei casi di CHL con normale otoscopia, timpanome-           Neck Surgery, University of Brescia, piazzale Spe-
tria e TC pre-operatorie trattati con ET dal 2011 al 2019. I dati demografici, audiometrici e      dali Civili 1, 25123 Brescia, Italy
relativi alla diagnosi intra-operatoria sono stati raccolti e analizzati per valutarne il valore   E-mail: tomasoni.michele@gmail.com
predittivo in termini di riduzione post-operatoria dell’air bone gap (ABG) e di soddisfa-
zione dei pazienti.                                                                                  How to cite this article: Tomasoni M, Bor-
Risultati. Sono stati inclusi 48 casi. L’ABG medio si è ridotto significativamente (p < 0,001)       setto D, Deretti A, et al. Exploratory tym-
dal pre-operatorio (38,4 dB) al post-operatorio (14,8 dB). Un ABG post-operatorio entro              panotomy in conductive hearing loss with
i 10 dB è stato osservato in 20 casi (41,7%). La soddisfazione generale è stata riportata            normal pre-operative investigations. Acta
nel 60% dei casi. La fissità stapediale è stata la diagnosi più frequente (47,9%) e signifi-         Otorhinolaryngol Ital 2022;42:569-581. https://
cativamente associata a un ABG post-operatorio più basso e a una migliore qualità di vita            doi.org/10.14639/0392-100X-N1933
percepita.
Conclusioni. Nella CHL con indagini pre-operatorie normali, l’ET rappresenta il tratta-            © Società Italiana di Otorinolaringoiatria
mento di prima scelta, sebbene i risultati audiometrici possano variare. Il riscontro intra-       e Chirurgia Cervico-Facciale
operatorio di fissità stapediale si associa a migliori risultati audiologici e di soddisfazione
del paziente.                                                                                                     OPEN ACCESS

                                                                                                   This is an open access article distributed in accordance with
PAROLE CHIAVE: ipoacusia trasmissiva, timpanotomia esplorativa, otosclerosi, chirurgia             the CC-BY-NC-ND (Creative Commons Attribution-Non-
della staffa, ossiculoplastica                                                                     Commercial-NoDerivatives 4.0 International) license. The
                                                                                                   article can be used by giving appropriate credit and mentio-
                                                                                                   ning the license, but only for non-commercial purposes and
                                                                                                   only in the original version. For further information: https://
                                                                                                   creativecommons.org/licenses/by-nc-nd/4.0/deed.en




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M. Tomasoni et al.




Introduction                                                      the results of treatment of conductive hearing loss” 5. ABG
                                                                  was defined as the mean value of the differences between the
Conductive hearing loss (CHL) is a frequently encountered
                                                                  air- and bone-conductions at 500, 1000, 2000 and 3000 Hz.
condition in the practice of otolaryngologists and can re-
                                                                  ABG reduction was defined as the difference between pre-
sult from a variety of pathologic conditions 1-3. An accurate
                                                                  operative and post-operative ABGs. Patient-referred out-
diagnosis is essential to offer patients the best treatment
                                                                  comes after surgery were measured by administration of the
option. Patients affected by CHL presenting with normal
                                                                  18-question “Glasgow Benefit Inventory (GBI)” question-
tympanic membrane, tympanometry and temporal bone
                                                                  naire at the latest follow-up evaluation 6. Patients were also
computed tomography (CT) represent a clinical challenge.
                                                                  asked if they were satisfied by the surgical procedure overall,
Exploratory tympanotomy (ET) is a diagnostic option that
                                                                  and if they would recommend the procedure.
allows surgeons to assess the middle ear (ME), eventually
tailoring treatment according to intraoperative findings.
                                                                  Statistical analysis
The aim of this study is to investigate whether patients pre-
                                                                  Characteristics of patients were expressed in terms of per-
senting with CHL, normal ME pressure and negative/non-
                                                                  centages, mean and relative standard deviation, median,
diagnostic pre-operative CT scan may benefit from a surgical
                                                                  inter-quartile range (IQR) and range.
intervention of exploratory tympanotomy, quantifying the air
bone gap (ABG) reduction that tailored surgery according          Continuous variables were tested for normal distribution
to intraoperative findings may offer. Moreover, patient and       with Shapiro-Wilk test. Parametric tests (ANOVA) and
treatment-related factors, as well as pre-operative audiologic    non-parametric tests (Mann-Whitney, Kruskall-Wallis,
data, were studied to assess their potential predictive role on   Wilcoxon signed-rank tests) were used as appropriate.
restoration of air-conduction. We also collected data on the      Spearman’s and Pearson’s rho were calculated to study
benefit perceived by patients following surgery, investigating    correlation between continuous variables. Relationship be-
variables that may influence patient satisfaction.                tween discrete variables was conducted with Fisher exact
                                                                  and Chi-squared tests, as appropriate.
                                                                  ROC curve analysis was used to determine the ideal cut-
Materials and methods                                             off according to Youden’s index in age at presentation, pre-
A retrospective analysis of consecutive patients undergo-         and post-operative ABG and ABG reduction according to
ing ET under local anaesthesia for CHL between September          overall satisfaction. AUC values > 0.70 were considered
2011 and November 2019 was conducted at the Department            satisfactory.
of Otolaryngology of the University of Brescia, Italy. All        Statistical analysis was performed using R (version 4.0.5,
patients presenting with CHL and normal tympanic mem-             R Foundation for Statistical Computing, Vienna, Austria);
brane underwent high-resolution temporal bone CT scan to          p-values < 0.05 were considered statistically significant.
confirm eligibility for surgical procedures of hearing restora-
tion, and for better definition of ME anatomy and potential       Results
surgical risks. Advantages and disadvantages of any possible
interventions were thoroughly discussed with patients.            During the period of investigation, 515 ears were scheduled
Inclusion criteria were: a) patients undergoing elective ET;      for surgical treatment of CHL with normal pre-operatory
b) with a preoperative air-bone gap (ABG) ≥ 20 dB at least        tympanic membrane and ear pressure. In 467 patients, the
in 2 frequencies (500-3000 Hz) 4 determined with a pure-          preoperatory CT scan was diagnostic for otosclerosis and
tonal audiometry (PTA); c) normal pre-operative micros-           stapedotomy was performed.
copy and oto-endoscopy; d) normal tympanometry (i.e.              The remaining 48 cases (9.3%) with a non-diagnostic pre-
pattern A); e) normal/non-diagnostic pre-operative ear CT         operatory CT scan were scheduled for exploratory tympa-
scan. Exclusion criteria were: a) age < 18-years; b) previ-       notomy and included in the current study. Cone beam CT
ous surgery in the affected ear; c) reporting symptoms con-       (CBCT) was performed in 28 patients (58.3%). Of these
sistent with third window disorders.                              patients, most were female (54.2%), with a mean age at
Surgical strategies were tailored according to intraopera-        surgery of 51.7 ± 14.0 years. Family history for otosclerosis
tive findings to restore hearing.                                 was recorded in 2 cases. Medical history revealed previous
Data regarding demographics, radiological, pre-and post-          contralateral ear surgery and long-standing head trauma in
operative PTA, intraoperative findings and surgical details       1 (2.1%) and 4 (8.3%) cases, respectively (Tab. I). Stape-
were anonymously collected in a dedicated database. PTA           dial reflexes were absent in all patients.
findings were analysed according to the “Committee on             The most frequent intraoperative finding was stapes fixation
Hearing and Equilibrium guidelines for the evaluation of          (23 cases, 47.9%), followed by ossicular chain discontinu-



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                                                                                                              Exploratory tympanotomy in conductive hearing loss




Table I. Most relevant patient and treatment-related variables.
 Variable                                                    N.              %
 Mean age ± SD (range) - yr 51.7 ± 14.0 (20-78)
 Gender                     Female                                26      54.2%
                            Male                                  22      45.8%
 Side                       Left                                  25      53.1%
                            Right                                 23      47.9%
 CT scan                    MSCT                                  20      41.7%
                            CBCT                                  28      58.3%
 History                    Family history of                      2       4.2%
                            otosclerosis
                            Head trauma                           4        8.3%
                            (long-term, > 1 year)
 Intraoperative findings    Stapes fixation                       23      47.9%
                            Incudo-malleolar ankylosis             6      12.5%
                            Ossicular chain discontinuity         11      22.9%
                                 - Incudo-stapedial               (6)     (54.5%)      Figure 1. Intraoperative findings and relative frequency (drawing by Michele
                                 dislocation                                           Tomasoni).
                                 - Erosion of the long            (2)     (18.2%)
                                 process of the incus
                                 - Severe erosion of the          (2)     (18.2%)      of the long process of the incus (2 cases, 18.2%). Ossicu-
                                 incus
                                                                                       lar chain ankylosis was always at the level of the incudo-
                                 - Stapes superstructure          (1)     (9.1%)
                                 fracture
                                                                                       malleolar joint. In patients affected by tympanosclerosis,
                               Tympanosclerosis                   8       16.7%
                                                                                       along with ME adherences, an incudo-malleolar ankylosis
                                                                                       was observed (4 cases, 50%), whereas stapes fixation, incu-
 Surgical procedure            Stapedotomy                        24       50%
                                                                                       do-stapedial dislocation and malleolar partial erosion was
                               Ossiculoplasty with                18      37.5%
                               remodeled incus                                         found in 1 case each (12.5%).
                               Interposition of bone or           4        8.3%        Stapedotomy was the most common procedure performed
                               cartilage fragment between                              (24 cases, 50%), followed by ossiculoplasty (23 cases,
                               the incus and the stapes                                47.9%) and lysis of ME adherences (1 case, 2.1%). Os-
                               TORP                               1        2.1%        siculoplasty was mostly performed by interposition of re-
                               Positioning of stapedial           1        2.1%        modeled incus (18 cases, 37.5%), whereas in the remaining
                               prosthesis without                                      cases interposition of bone or cartilage fragment (4 cases,
                               stapedotomy
                                                                                       8.3%), total ossicular replacement prosthesis (TORP, 1
                               Lysis of ME adherences             1       2.1%         case, 2.1%) and stapedial prosthesis without stapedotomy
 Intraoperative                Injury of the chorda tympani       7       14.6%        (1 case, 2.1%) was performed. Intraoperative complica-
 complications
                                                                                       tions were limited to chorda tympani injury, reported in 7
 Post-operative           Temporary dizziness                     3        6.2%
 complications
                                                                                       cases (14.6%). Details of each patient included are reported
                                                                                       in Table S1 (supplementary material). Except for 3 cases of
 Median GBI score (range) 18, IQR:33.3 (-47.2, 55.5)
                                                                                       temporary dizziness, no other post-operative complications
 Overall satisfaction     Yes                                     24       60%
                                                                                       were recorded.
                          No                                      16       40%
                          Unknown                                 (8)
                                                                                       Hearing outcomes
CBCT: cone beam computed tomography; IQR: Interquartile range; ME: middle ear;
MSCT: multi-slice computed tomography; TORP: total ossicular replacement prosthesis.   Mean values of pre- and post-operative air- and bone-conduc-
                                                                                       tion at 500, 1000, 2000 and 3000 Hz are depicted in Figure 2.
                                                                                       Mean pre-operative and post-operative ABG were 38.4
                                                                                       (range: 15-64) and 14.8 (range: 0-56), with a significant
ity (11 cases, 22.9%), tympanosclerosis (8 cases, 16.7%)
                                                                                       ABG reduction after surgery (Wilcoxon signed-rank test,
and ossicular chain ankylosis (6 cases, 12.5%) (Fig. 1). Os-                           p < 0.001) of 24 ± 15 dB (Fig. 2). In 1 case, (2.1%) an
sicular chain discontinuity was mostly caused by incudo-                               increase of ABG after surgery was observed (stapedotomy
stapedial dislocation (6 cases, 54.5%), followed by erosion                            performed for a pre-operative CHL of 29 dB).



                                                                                                                                                             571
M. Tomasoni et al.




Figure 2. On the left, pure tone audiometry reporting the mean pre-operative (black) and post-operative (blue) air-conduction and bone-conduction thresholds.
Values are reported with symbols for left ear by way of example. On the right, p-paired test showing the significant reduction in air-bone gap following surgery in
our cohort of patients.


Post-operative ABG < 10 dB was observed in 20 cases                                 lower ABG after treatment (9.4, IQR = 7.8) compared to
(41.7%) and between 10-20 dB in 15 cases (31.2%). Non-                              patients treated with ossiculoplasty with remodelled incus
satisfactory postoperative ABG (> 20 dB) was observed in                            (18.1, IQR = 8.1) or other procedures (22.5, IQR = 18.7).
14 cases (29.2%) (Tab. S1). A significant positive correla-                         No significant differences in ABG reduction were observed
tion was observed between pre-operative ABG and ABG                                 according to intraoperative findings (p = 0.53) or surgical
reduction (R = 0.62, p < 0.001) (Fig. 3A).                                          procedure performed (p = 0.39) (Fig. S1).
Age at surgery, gender and side of treated ear were not sig-
nificantly associated with any auditory measure, namely                             Patient-reported outcomes
pre- and post-operative ABG and ABG.                                                GBI total score was available for 38 patients (79.2%)
Pre-operative ABG was not significantly associated with                             and ranged from -47.2 to 55.5, with a median value of 18
intraoperative findings (p = 0.510), as well.                                       (IQR = 33.3).
Post-operative ABG was significantly influenced by in-                              Both post-operative ABG (R = -0.45, p = 0.004) and ABG
traoperative findings (p=0.006) and surgical procedure                              reduction (R = 0.36, p = 0.024) were significantly corre-
(p = 0.009) (Fig. 4). Patients affected by stapes fixation                          lated with perceived benefit (Fig. 3B-C). No correlation
had a median post-operative ABG of 8.7 (IQR = 7.5),                                 was found with pre-operative ABG (p = 0.660), age at sur-
and significantly lower than patients affected by ossicular                         gery (p = 0.683), gender (p = 0.672), side (p = 0.110), or
chain discontinuity (17.5, IQR = 16.9), ankylosis (19.4,                            chorda tympani injury (p = 0.840). Better GBI scores were
IQR = 5.9) or tympanosclerosis (21.2, IQR = 4.7). Similar-                          reported by patients affected by otosclerosis (p = 0.063)
ly, patients treated with stapedotomy showed significantly                          (Fig. S2).



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                                                                                                            Exploratory tympanotomy in conductive hearing loss




A                                                       B                                                    C




Figure 3. (A) positive correlation between pre-operative air-bone gap (ABG) and ABG reduction (r = 0.64, p < 0.001); (B) negative correlation between post-
operative ABG (r = -0.44, p = 0.005) and perceived benefit from surgery reported by patients through the “Glasgow Benefit Inventory (GBI)” questionnaire; (C) posi-
tive correlation between ABG reduction and GBI score (r = 0.41, p = 0.009).



A                                                                                  B




                                                               OC: ossicular chain; OPL: ossiculoplasty

Figure 4. (A) box-plots showing the significant difference (p = 0.011) in post-operative ABG according to intraoperative findings; (B) box-plots showing the sig-
nificant difference (p = 0.018) in post-operative ABG according to surgery performed, tailored on intraoperative findings.


Overall satisfaction was reported by 60% of patients, with                             of personal satisfaction in patients aged < 57-years
a mean GBI score of 31.9 (IQR = 20.2, range: 11.1-55.5).                               (AUC = 0.706), showing post-operative ABG closure
Patients who declared not to be satisfied with the surgical                            < 13.1 dB (AUC = 0.855) or ABG reduction > 28.7 dB
procedure reported a mean GBI of -8.3 (IQR = 25, range:                                (AUC = 0.725) (Fig. S3). No ideal cut-offs were found ac-
-47.2-11.2). Patients affected by otosclerosis were signifi-                           cording to pre-operative ABG.
cantly more satisfied (p = 0.025), whereas no significant
association was found between overall satisfaction and
                                                                                       Discussion
gender (p = 0.990), side (p = 0.486), chorda tympani injury
(p = 0.844), pre-operative mean air-conduction thresholds                              The main goal of the current study was to investigate in-
(p = 0.280), or pre-operative ABG (p = 0.930).                                         traoperative findings, auditory outcomes and related pre-
ROC curve analysis showed better results in terms                                      dictive factors in a population of patients affected by CHL



                                                                                                                                                             573
M. Tomasoni et al.




presenting with normal pre-operative otoscopy, ME pres-          The relative frequency (47.9%) of occult otosclerosis in our
sure and CT scan.                                                cohort was also reported by previous studies 7,11,15. In these
In this subset of patients, pre-operative PTA showed mean        cases, the degenerative otospongiotic process, originating
threshold values of air- and bone-conduction of 61.6 and         from the fissula ante-fenestram, was probably wide enough
23.2 dB, respectively, with a relative ABG of 38.4 dB.           to cause footplate fixation but not to be clearly depictable
The wide pre-operative ABG may be explained with the             on pre-operative CT scan. In our experience, ossicular
fact that there were patients suffering from CHL with no         chain discontinuity (22.9%), ankylosis (12.5%) and tym-
pre-operative evidence of ME disorders. In this setting, the     panosclerosis (16.7%) were less common. The relative pro-
surgeon cannot provide a reliable prediction of hearing res-     portion of pathologic conditions underlying CHL is similar
toration and surgical risks, commonly resulting in a delay       to previous publications 11,16.
of the procedure.                                                As expected, stapedotomy was the most common surgery
The diagnostic accuracy of CT scan in the setting of CHL has     performed (50%), followed by ossiculoplasty with remod-
been widely demonstrated in acute and chronic inflammatory       eled incus (37.5%). Similar results were reported by Kim
disorders and otosclerosis, whereas it is not well established   et al., reporting most patients undergoing stapedotomy
in the rare occurrence of ossicular malformations or dislo-      (77%) 11. On the contrary, the most common surgical proce-
cation 7-9. In our experience, in 467 cases stapedotomy was      dure reported by Choi et al. was ossiculoplasty with PORP
scheduled following a radiological diagnosis of otosclerosis,    (49%), followed by stapedotomy (23%) and TORP (23%),
whereas in 23 cases the exploratory tympanotomy revealed         although in that study pre-operative CT findings were not
stapes fixation with normal pre-operative temporal bone CT       considered 7.
scan. The overall accuracy of CT scan was 95.3%. Patients        In our cohort, ET was a safe and effective procedure. In-
included in the current study often underwent preoperative       traoperative complications consisted exclusively of acci-
CBCT (58.3%), which was at least as accurate as multi-slice      dental injury of the chorda tympani (14.6%), whereas after
CT or even superior in assessing structures related to con-      surgery only 3 cases of transitory dizziness were observed.
ductive hearing loss, with lower radiation exposure 10.          However, it should be kept in mind that occult otosclerosis
In our cohort, a slightly higher proportion of female pa-        is the most common finding during ET. Since stapedotomy
tients was observed (54.2%), with a mean age of 51.7 ± 14        carries a non-negligible rate of potentially severe complica-
years. These results reflect the well-known distribution of      tions, surgical indication is discussed with patients when at
CHL in the general population, primarily driven by oto-          least 20 dB of ABG is present.
sclerosis 7,11-13. Previous head trauma (8.3%) was reported      Mean air-conduction threshold on 0.5-3 kHz went from a
less frequently compared to similar studies (Choi et al.,        preoperative value of 61.6 to 42.6 dB after surgery, with a
29%) 7, whereas family history of otosclerosis was rarely        net mean gain of 23.1 dB, regardless the undergoing dis-
reported (4.2%), even if we consider only patients with sta-     ease or surgery performed. Similar findings were reported
pes fixation (8.7%). Since all these patients had a normal       by Kim et al. (17.3 dB) 11 and Choi et al. (19.4 dB) 7.
pre-operative CT scan, the form of otosclerosis might be         Most of our patients showed an excellent (< 10 dB, 41.7%)
considered “mild” and potentially unrecognised and misdi-        or good post-operative ABG (10-20 dB, 31.2%), whereas
agnosed within the family 12.                                    non-satisfactory post-operative ABG (> 20 dB) was ob-
As described by Hong et al. 14, patients with CHL and ab-        served in 14 cases (29.2%). Only 1 patient (2.1%) expe-
sent acoustic reflexes generally are affected by ossicular       rienced an increase in the ABG (secondary to stapedoto-
disorders, most commonly, but not exclusively, secondary         my). Similar results were reported by Kim et al. 11, with
to otosclerosis. The detection of even one acoustic reflex       excellent, good and non-satisfactory ABG closure found in
should prompt further workup prior to ME exploration in          47.8, 32.8 and 19.4% of cases, respectively. The increase
the suspicion of third-window disorders. In our cohort, all      in the proportion of cases of ABG was comparable as well
patients undergoing ET had absent acoustic reflexes. How-        (5.3%), but in the experience of Kim et al. 11 this occurred
ever, in the experience of Hong et al. 14, a non-negligible      after surgery for ossicular fixation and discontinuity.
rate of patients with an ossicular aetiology of CHL had          None of the preoperative variables under study (sex, side
detectable acoustic reflexes, concluding that the reflex test    and age at diagnosis) were useful in predicting auditory re-
should not be considered infallible. For this reason, we do      covery after treatment. The only positive association found
not recommend considering the stapedial reflex as a rel-         was between preoperative ABG and postoperative ABG re-
evant variable in the decision-making algorithm for an ET        duction, suggesting that good ABG closure is achievable
in the case of a CHL with normal otoscopy, radiology and         even in worst-case scenarios of large preoperative gap.
tympanogram.                                                     Conversely, intra-operative findings and the surgical proce-



574
                                                                                           Exploratory tympanotomy in conductive hearing loss




dure performed accordingly were better prognosticators of          ing agencies in the public, commercial, or not-for-profit
successful auditory recovery. When ET was diagnostic for           sectors.
stapes fixation and stapedotomy was performed, patients
experienced better outcomes in terms of post-operative             Author contributions
ABG closure, confirming what was previously described              Study design and concept: TS. Material preparation and
by Kim et al. and Choi et al. 7,11.                                ethical aspects: ADer, TS, ADeg. Data collection: ADer,
These results make audiological outcomes poorly predict-           MT. Data analysis: MT, DB, TS. Writing and editing: MT,
able in the pre-operative setting, apart from the general ex-      DB, MA, AS, SZ. Critical Revision: LRdZ, CP, ADeg, TS.
pectation of greater ABG reduction in patients with higher
pre-operative ABG 11.                                              Ethical consideration
As expected, higher GBI score was reported when lower              This study was approved by the Institutional Ethics Com-
postoperative ABG (R = -0.45) and greater ABG reduction            mittee of the University of Brescia (approval number
(R = 0.36) were achieved, and when patients were diag-             N4357).
nosed with otosclerosis, although only a close-to-signifi-         The research was conducted ethically, with all study pro-
cant association was found (p = 0.063).                            cedures being performed in accordance with the require-
When asked to express their general satisfaction, younger          ments of the World Medical Association’s Declaration of
patients (< 57-years at surgery), with excellent post-opera-       Helsinki.
tive auditory outcomes (ABG < 13.1 dB or ABG reduction             Written informed consent was obtained from each partici-
> 28.7 dB) were more satisfied. The possible explanation           pant/patient for study participation and data publication.
for better satisfaction outcomes in younger patients may
come from the higher proportion of otosclerosis, as con-           References
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retrospective study based on a relatively small number of          2
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                                                                   3
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a partial clue of better results. Surgeons should be prepared           Larynx 2016;43:144-148. https://doi.org/10.1016/j.anl.2015.06.004
to tailor surgery according to intraoperative findings with        8
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sclerosis was the most common diagnosis, with the best                  1159. https://doi.org/10.1097/MAO.0b013e3181c2a084
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                                                                        Kemp P, Stralen JV, De Graaf P, et al. Cone-beam CT compared to
                                                                        Multi-Slice CT for the diagnostic analysis of conductive hearing
Conflict of interest statement                                          loss: a feasibility study. J Int Adv Otol 2020;16:222-226. https://doi.
The authors declare no conflict of interest.                            org/10.5152/iao.2020.5883
                                                                   11
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     ing of conductive hearing loss for third window disorders. Oto-               doi.org/10.1111/coa.12461




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               Supplementary material
               Table S1. Details of each patient included in the study.
                Patient AGE GENDER SIDE ABGPRE                     Intra-operative        Diagnosis             Surgical         Intra-operative ABGPOST    ABG        ABG     Overall      GBI total
                                                                        findings          proposed             procedure          complications          reduction   closure satisfaction    score
                    N1     68        F        Left    26.25      Incudo-malleolar       Ossicular chain    Ossiculoplasty with       None          20        6        < 10
                                                                      ankylosis            ankylosis        remodeled incus
                    N2     67        F       Right     57.5      Incudo-stapedial       Ossicular chain    Ossiculoplasty with       None         17.5      40        > 20        No           17
                                                                dislocation, incudo-     discontinuity      remodeled incus
                                                                malleolar ankylosis
                    N3     78        F        Left     37.5      Incudo-stapedial       Ossicular chain    Ossiculoplasty with       None         17.5      20       10-20        No          -47
                                                                     dislocation         discontinuity      remodeled incus
                    N4     72        M       Right    28.75        Stapes fixation       Otosclerosis         Stapedotomy         Lesion of the   47.5      -19        X          No
                                                                                                                                 Chorda Tympani
                    N5     49        F       Right      30       Erosion of the long    Ossicular chain    Ossiculoplasty with        None         0        30        > 20
                                                                process of the incus     discontinuity       remodeled incus
                    N6     32        F       Right    41.25       Incudo-stapedial      Ossicular chain       Interposition of       None          5        36        > 20        Yes          50
                                                                     dislocation         discontinuity     bone (from the EAC)
                                                                                                            between the incus
                                                                                                              and the stapes,
                                                                                                               stabilized with
                                                                                                                  cement
                    N7     56        F       Left     23.75        Stapes fixation       Otosclerosis          Stapedotomy           None         11.25     13       10-20        Yes          28
                    N8     62        M       Right    36.25        ME adherences       Tympanosclerosis    Ossiculoplasty with       None          15       21       > 20         No          -11
                                                                    with incudo-                             remodeled incus
                                                                 malleolar ankylosis
                    N9     22        M       Right     20          Stapes fixation       Otosclerosis         Stapedotomy             None          0       20       10-20        Yes          31
                    N10    68        M       Left     28.75       Incudo-malleolar      Ossicular chain    Ossiculoplasty with    Lesion of the   18.75     10       10-20        No           -6
                                                                      ankylosis            ankylosis        remodeled incus      Chorda Tympani
                    N11    38        F       Right    36.25        Stapes fixation       Otosclerosis         Stapedotomy             None          0       36        > 20        Yes          39
                    N12    58        F       Left     18.75        Stapes fixation       Otosclerosis         Stapedotomy             None         10        9        < 10        No           8
                    N13    20        M       Right     30        Erosion of the long    Ossicular chain    Ossiculoplasty with        None        23.75     6         < 10
                                                                process of the incus     discontinuity      remodeled incus
                    N14    35        M       Right      55         Stapes fixation       Otosclerosis         Stapedotomy         Lesion of the   12,5      43        > 20        Yes          42
                                                                                                                                 Chorda Tympani
                    N15    42        F        Left      45       Severe erosion of      Ossicular chain    Tympanoplasty type         None        13,75     31        > 20
                                                                    the incus            discontinuity      IV (interposition of
                                                                                                           cartilage fragment)
                    N16    46        F       Right      35         Stapes fixation       Otosclerosis          Stapedotomy        Lesion of the    0        35        > 20        Yes          33
                                                                                                                                 Chorda Tympani
                    N17    34        M       Right    46.25     ME adherences and      Tympanosclerosis,        Lysis of ME           None        11.25     35        > 20        Yes          25
                                                                 incudo-stapedial        ossicular chain        adherences,
                                                                    dislocation           discontinuity    ossiculoplasty with
                                                                                                             remodeled incus




577
      continues u
                                                                                                                                                                                                        Exploratory tympanotomy in conductive hearing loss
               TTable S1. Details of each patient included in the study (follows).




578
                Patient AGE GENDER SIDE ABGPRE                    Intra-operative         Diagnosis             Surgical         Intra-operative ABGPOST    ABG        ABG     Overall      GBI total
                                                                      findings            proposed             procedure          complications          reduction   closure satisfaction    score
                    N18    50        F        Left     45          Stapes fixation        Otosclerosis        Stapedotomy            None          10       35        > 20        Yes          11
                    N19    31        F        Left    38.75        Stapes fixation        Otosclerosis        Stapedotomy            None          15       24        > 20        No          -17
                                                                                                                                                                                                        M. Tomasoni et al.




                    N20    49        M        Left    27.5        ME adherences,       Tympanosclerosis,       Lysis of ME           None         22.5      5         < 10        No          -17
                                                                  malleolar partial      ossicular chain      adherences,
                                                                  erosion (incudo-        discontinuity      tympanoplasty
                                                                      malleolar                                   type II
                                                                    dislocation)
                    N21    38        F        Left    63.75      Incudo-malleolar       Ossicular chain    Ossiculoplasty with       None         56.25      8        < 10        No          -42
                                                                      ankylosis           ankylosis         remodeled incus
                    N22    44        F       Right    61.25       ME adherences        Tympanosclerosis       Stapedotomy         Lesion of the   21.25     40        > 20        No           0
                                                                with stapes fixation                                             Chorda Tympani
                    N23    26        M        Left    36.25        Severe erosion       Ossicular chain          TORP                 None        28.75      8        < 10        Yes          47
                                                                    of the incus         discontinuity
                                                                     and stapes
                                                                   superstructure
                    N24    35        F       Right    23.75      Incudo-stapedial       Ossicular chain    Ossiculoplasty with    Lesion of the    0        24        > 20        Yes          11
                                                                    and incudo-          discontinuity      remodeled incus      Chorda Tympani
                                                                      malleolar
                                                                     dislocation
                    N25    57        F        Left      40        ME adherences        Tympanosclerosis    Ossiculoplasty with       None          20       20       10-20
                                                                    with incudo-                            remodeled incus
                                                                malleolar ankylosis
                    N26    54        F        Left     35          Stapes fixation       Otosclerosis         Stapedotomy            None          12.5     23        > 20        Yes          31
                    N27    55        M        Left    48.75        Stapes fixation       Otosclerosis         Stapedotomy            None           5       44        > 20
                    N28    37        F        Left    38.75        Stapes fixation       Otosclerosis         Stapedotomy            None         11.25     28        > 20        No            0
                    N29    42        M        Left    32.5       Incudo-malleolar       Ossicular chain    Ossiculoplasty with       None          2,5      30        > 20        Yes          28
                                                                      ankylosis            ankylosis        remodeled incus
                    N30    66        F        Left     37.5      Incudo-stapedial       Ossicular chain      Interposition of        None         37.5       0        < 10        No
                                                                     dislocation         discontinuity     cartilage fragment
                                                                                                           between the incus
                                                                                                             and the stapes
                    N31    72        M       Right     15          Stapes fixation       Otosclerosis         Stapedotomy            None          6.25      9        < 10        Yes          33
                    N32    64        F       Right    41.25       Incudo-malleolar      Ossicular chain    Ossiculoplasty with       None         13.75     28        > 20        No          -44
                                                                      ankylosis           ankylosis         remodeled incus
                    N33    52        M       Right    28.75        Stapes fixation       Otosclerosis         Stapedotomy            None         8.75      20       10-20        Yes          47
                    N34    56        F       Left     23.75        Stapes fixation       Otosclerosis         Stapedotomy            None         6.25      18       10-20        Yes          11
                    N35    45        M       Left     62.5         Stapes fixation       Otosclerosis         Stapedotomy            None          0        63       > 20         Yes          19
                    N36    45        M       Right     35          Stapes fixation       Otosclerosis         Stapedotomy            None         2.5       33       > 20         Yes          19
                    N37    56        M       Right    22.5         Stapes fixation       Otosclerosis         Stapedotomy            None         22.5      0        < 10         No          -28




      continues u
      TTable S1. Details of each patient included in the study (follows).
       Patient AGE GENDER SIDE ABGPRE                    Intra-operative         Diagnosis            Surgical         Intra-operative ABGPOST    ABG        ABG     Overall      GBI total
                                                             findings            proposed            procedure          complications          reduction   closure satisfaction    score
       N38        60        F        Left    46.25       Incudo-stapedial      Ossicular chain     Interposition of        None         22.5      24        > 20                     11
                                                            dislocation         discontinuity    cartilage fragment
                                                                                                 between the incus
                                                                                                   and the stapes
       N39        51        M       Right     35         Stapes fixation        Otosclerosis        Stapedotomy            None          7.5      28       > 20
       N40        71        M       Right    51.25       ME adherences        Tympanosclerosis       Lysis of ME           None         41.25     10       10-20        No           0
                                                                                                     adherences
       N41        54        M       Right    46.25       Stapes fixation        Otosclerosis        Stapedotomy            None          10       36        > 20        Yes          39
       N42        61        M       Left     53.75       ME adherences        Tympanosclerosis   Ossiculoplasty with       None         21.25     33        > 20        Yes          33
                                                          with incudo-                            remodeled incus
                                                        malleolar ankylosis
       N43        55        M        Left     22.5       Stapes fixation        Otosclerosis        Stapedotomy         Lesion of the    15        8        < 10        Yes          11
                                                                                                                       Chorda Tympani
       N44        49        F       Right    38.75        Stapes fixation       Otosclerosis        Stapedotomy             None         3.75     35       > 20         Yes          56
       N45        61        F       Left     41.25       Incudo-malleolar      Ossicular chain   Ossiculoplasty with        None        21.25     20       10-20        Yes          36
                                                             ankylosis           ankylosis        remodeled incus
       N46        63        F       Right    41.25        ME adherences       Tympanosclerosis   Ossiculoplasty with       None         26.25     15       10-20
                                                           with incudo-                           remodeled incus
                                                        malleolar ankylosis
       N47        67        M       Right    53.75             Stapes          Ossicular chain       Positioning           None          7.5      46        > 20        No           6
                                                          suprastructure        discontinuity        of stapedial
                                                              fracture                           prosthesis without
                                                                                                    stapedotomy
       N48        71        F       Right    58.75        Stapes fixation       Otosclerosis       Stapedotomy             None         6.25      53        > 20        Yes          44




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                                                                                                                                                                                              Exploratory tympanotomy in conductive hearing loss
M. Tomasoni et al.




A                                                                                  B




                                                              OC: ossicular chain; OPL: ossiculoplasty


Figure S1. (A) Box-plots showing the non-significant difference in ABG reduction according to intraoperative findings; (B) Box-plots showing the non-significant
difference in ABG reduction according to surgery performed, tailored on intraoperative findings.




                         GBI: Glasgow Benefit Inventory


Figure S2. Box-plots showing the close-to-significant (p = 0.063) differ-
ence in GBI score according to intra-operative findings.




580
                                                                                                       Exploratory tympanotomy in conductive hearing loss




Figure S3. ROC curve analysis showing the ideal cut-off in age (57 years, AUC = 0.706), post-operative ABG closure (13.1 dB, AUC = 0.855) and ABG reduction
(28.7 dB, AUC = 0.750) according to overall satisfaction reported by patients using the “Glasgow Benefit Inventory (GBI)” questionnaire.




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