10.14639/0392-100X-N1237
Objective. Cochlear fistula (CF) is a rare finding, usually associated with extensive middle ear cholesteatoma. There is agreement on the fact that removing the cholesteatoma matrix on a CF exposes the ear to a high risk of sensorineural hearing loss or dead ear. The aim of the study is to describe the presentation, possible treatment strategies and related outcomes for patients with CF in chronic otitis media (COM). Methods. The study considers a retrospective case series of patients with CF diagnosis supported by CT-scan and intraoperative/otoscopic evidence. Results. Five cases of CF were identified, 4 associated with cholesteatoma and 1 associated with non-cholesteatomatous COM. Two patients presenting with anacusis underwent a subtotal petrosectomy. Two patients with useful hearing underwent a radical mastoidectomy in order to preserve the cholesteatoma matrix on the promontorium. One patient with good hearing and COM was treated conservatively. Conclusions. Conservative management should be considered for rare cases of CF in COM with residual hearing. Matrix preservation through radical/modified radical mastoidectomy is strongly advised in the presence of useful preoperative bone conduction. Subtotal petrosectomy should be considered the preferred option in presence of cholesteatoma with preoperative profound hearing loss.
text/xml
1827-675X
1237
en
Filippo Di Lella
http://creativecommons.org/licenses/by-nc-nd/4.0
ACTA Otorhinolaryngologica Italica
cholesteatoma
Management of cochlear fistula and the role of hearing: a five-case report
Text.Serial.Journal
https://www.actaitalica.it/
41
Otology
2021-12-21
2020-11-11
2021-12-22
2021-12-22
558-565
1
Filippo Di Lella
2021/12/21
10.14639/0392-100X-N1237
558
Unit of Otorhinolaryngology and Otoneurosurgery, University of Parma, Department of Medicine and Surgery, Parma, Italy
1827-675X
cholesteatoma
en
565
Management of cochlear fistula and the role of hearing: a five-case report
https://www.actaitalica.it/article/download/1237/723
41
ACTA OTORHINOLARYNGOLOGICA ITALICA 2021;41:558-565; doi: 10.14639/0392-100X-N1237




Otology


Management of cochlear fistula and the role
of hearing: a five-case report
Gestione della fistola cocleare e il ruolo dell’udito: report di 5 casi
Maurizio Falcioni1, Marco Govoni2, Enrico Pasanisi2, Filippo Di Lella2
1
  Unit of Otorhinolaryngology and Otoneurosurgery, University Hospital of Parma, AOU Parma, Parma, Italy; 2 Unit of
Otorhinolaryngology and Otoneurosurgery, University of Parma, Department of Medicine and Surgery, Parma, Italy


SUMMARY
Objective. Cochlear fistula (CF) is a rare finding, usually associated with extensive middle
ear cholesteatoma. There is agreement on the fact that removing the cholesteatoma matrix
on a CF exposes the ear to a high risk of sensorineural hearing loss or dead ear. The aim of
the study is to describe the presentation, possible treatment strategies and related outcomes
for patients with CF in chronic otitis media (COM).
Methods. The study considers a retrospective case series of patients with CF diagnosis sup-
ported by CT-scan and intraoperative/otoscopic evidence.
Results. Five cases of CF were identified, 4 associated with cholesteatoma and 1 as-
sociated with non-cholesteatomatous COM. Two patients presenting with anacusis un-
derwent a subtotal petrosectomy. Two patients with useful hearing underwent a radical
mastoidectomy in order to preserve the cholesteatoma matrix on the promontorium.
One patient with good hearing and COM was treated conservatively.
Conclusions. Conservative management should be considered for rare cases of CF in COM
with residual hearing. Matrix preservation through radical/modified radical mastoidectomy
                                                                                                  Received: November 11, 2020
is strongly advised in the presence of useful preoperative bone conduction. Subtotal pet-
                                                                                                  Accepted: July 23, 2021
rosectomy should be considered the preferred option in presence of cholesteatoma with
preoperative profound hearing loss.
                                                                                                  Correspondence
KEY WORDS: cochlear fistula, promontory fistula, otitis media, cholesteatoma                      Marco Govoni
                                                                                                  Department of Otorhinolaryngology and Otoneuro-
                                                                                                  surgery, University Hospital of Parma, via Gramsci
RIASSUNTO                                                                                         14, 43126 Parma, Italy
Obiettivo. La fistola cocleare (FC) è una rara entità, solitamente associata a colesteatoma       E-mail: marco.govoni90@gmail.com
dell’orecchio medio. Vi è generale accordo in letteratura sul fatto che la rimozione della
matrice colesteatomatosa da una FC determini elevato rischio di ipoacusia neurosenso-             Funding
riale o anacusia. Obiettivo dello studio è descrivere manifestazioni, possibili trattamenti e     None.
prognosi per pazienti affetti da FC.
Metodi. Serie retrospettiva di casi clinici di fistola cocleare confermati da TC e da riscontro   Conflict of interest
intraoperatorio o endoscopico.                                                                    The Authors declare no conflict of interest.
Risultati. Di 5 casi identificati, 4 si associavano a colesteatoma. Di questi, 2 pazienti ana-
cusici venivano sottoposti a petrosectomia subtotale, mentre 2 pazienti udenti venivano             How to cite this article: Falcioni M, Govoni M,
sottoposti a intervento di radicale con preservazione della matrice sul promontorio. Il solo        Pasanisi E, et al. Management of cochlear fistula
caso di FC associato a otite cronica non-colesteatomatosa (OMC) e con buon udito residuo            and the role of hearing: a five-case report. Acta
veniva trattato conservativamente.                                                                  Otorhinolaryngol Ital 2021;41:558-565. https://
Conclusioni. Per quei rari casi di FC associati a OMC con buon udito residuo dovrebbe               doi.org/10.14639/0392-100X-N1237
essere considerato un trattamento conservativo. In caso di via ossea preoperatoria prote-
sizzabile, è fortemente indicata la preservazione della matrice di colesteatoma mediante          © Società Italiana di Otorinolaringoiatria
mastoidectomia radicale o radicale modificata. In presenza di colesteatoma con perdita            e Chirurgia Cervico-Facciale
uditiva profonda pre-operatoria, una petrosectomia subtotale dovrebbe essere il tratta-
mento di scelta.                                                                                                 OPEN ACCESS

PAROLE CHIAVE: fistola cocleare, fistola promontoriale, otite media, colesteatoma                 This is an open access article distributed in accordance with
                                                                                                  the CC-BY-NC-ND (Creative Commons Attribution-Non-
                                                                                                  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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                                                                                                   A five-case report on cochlear fistula




Introduction                                                      tional Review Board, as specifically indicated (version 3,
                                                                  03-07-2019). All procedures performed in this study in-
Labyrinthine fistula is one of the most common compli-
                                                                  volving human participants were in accordance with the
cations of cholesteatomatous-COM. It consists in a defect
                                                                  1964 Helsinki declaration and its later amendments or
of the bony labyrinth, resulting in a direct contact between
                                                                  comparable ethical standards. No animals were involved.
the cholesteatoma matrix and the labyrinthine endosteum
or the membranous labyrinth 1,2. The entire labyrinth can
potentially be involved with the lateral semicircular canal       Results
as the most frequent site 3. Cochlear involvement is a rare       A total of 5 CFs were identified in 5 patients (3 females
finding and cochlear fistula (CF) is usually associated with      and 2 males, age range 27 to 85 years, mean age 60 years).
extensive middle ear cholesteatoma; association with non-         Ipsilateral pure tone audiometry revealed pre-operative
cholesteatomatous-COM is an even rarer entity 4-6. For this       anacusis in 2 cases and mixed hearing loss in 3 cases. Four
reason, there are only few papers (excluding single case          patients (80%) referred vertigo or instability as presenting
reports) focusing exclusively on CF 7,8.                          symptoms. In 3 cases instability was still present at the time
Preoperative clinical diagnosis of CF may be difficult as         of consultation. One patient (20%) complained of tinnitus.
there are no specific audiological or otologic signs and
                                                                  Four patients (80%) had a history of previous otologic sur-
symptoms 4. Severe or profound sensorineural hearing loss
                                                                  gery on the affected side. For each patient, a preoperative
(SNHL) is a frequent finding, but hearing examination can
                                                                  HRCT of the ear confirming the diagnosis was available.
show a normal bony threshold as well. High resolution CT
                                                                  In 4 cases (80%), imaging evaluation led to preoperative
scan (HRCT) is a reliable imaging procedure for diagnosis
                                                                  diagnosis of CF, while in 1 case the fistula was detected
of CF, which typically appears as an erosion of the dense
                                                                  during surgery. Four fistulae were located on the promonto-
bone of the promontory 3,6. An unrecognised CF repre-
                                                                  rial dome and 1 in continuity with the inferior border of the
sents a challenging situation during surgery, as inadvertent
                                                                  oval window.
manipulation of the fistula is commonly associated with
                                                                  Four patients were treated surgically and one was man-
profound sensorineural hearing loss or dead ear 1. Factors
                                                                  aged conservatively. The follow-up period ranged from
considered in therapeutic planning of a CF management
usually include preoperative hearing status and disease ex-       17 months to 15 years, with an average of 59 months. The
tension (as documented by imaging) 9. We report our expe-         3 patients with measurable hearing at diagnosis did not
riences on a series of CFs with the purpose of discussing         show significant changes in the bony hearing threshold
clinical aspects, surgical or conservative treatments and         at the latest follow-up. No cholesteatoma recurrence was
evaluating the results of long-term management.                   identified.
                                                                  Details of clinical cases, treatment planning and surgical
                                                                  procedures are reported in the case discussions below. Two
Materials and methods                                             of the cases included in the present series (patient 3 and 4)
A retrospective chart review of patients treated by the authors   have been reported in previous publications 3,10.
between January 2005 and December 2017 was performed
to examine clinical aspects and outcomes, of both surgical        Case descriptions
and conservative treatments, for patients affected by CF.
CF was defined as an opening in the cochlear bony labyrinth       Patient 1
with exposure of the endosteal membrane; blue line cases          A 65-year-old female presented with complete deafness of
were not included nor were patients affected by petrous bone      the left ear, associated with recurrent otorrhoea, pain and
cholesteatoma or other erosive skull base lesions. Only pa-       mild vertigo for about 7 years. She referred a history of pre-
tients with a minimum follow-up of 12 months were enrolled.       vious ipsilateral canal-wall-down tympanomastoidectomy
All available preoperative, postoperative and follow-up           (CWD) for cholesteatoma performed 36 years before. Au-
documentation (clinical history, otoscopic pictures, au-          diogram showed left ear anacusis and right normoacusis. On
diological evaluations, imaging studies and operative find-       otoscopy a recurrent cholesteatoma was present in the left
ings) were retrospectively reviewed. Pure-tone average of         sided cavity. CT-scan showed erosion of the promontorium
air conduction (AC-PTA) was calculated by averaging air-          with an area of ossification in the basal turn of the scala tym-
conduction thresholds at 0.5, 1, 2 and 4 kHz. The same val-       pani (Fig. 1). MRI confirmed focal absence of fluid into the
ues were considered for calculating the pure-tone average         scala tympani. A subtotal petrosectomy (SP) was performed
of bone-conduction (BC-PTA).                                      with complete cholesteatoma removal. Intraoperatively, the
This study did not need any approval by the local Institu-        endosteum of the CF appeared preserved at the level of the



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M. Falcioni et al.




Figure 1. Patient 1. Temporal bone HRCT axial view (left ear): promontorial   Figure 3. Patient 2. Temporal bone HRCT coronal view (right ear): an ero-
erosion with focal ossification of the scala tympani (arrow).                 sion of the promontory with a large fistula of the basal turn of the cochlea can
                                                                              be seen (arrow).


                                                                              Patient 2
                                                                              A 85-year-old female presented with worsening right sided
                                                                              hearing loss, which occurred after a week of violent vertigo
                                                                              and spontaneously resolved. She also reported a 10-year
                                                                              history of ipsilateral tinnitus and a previous ipsilateral radi-
                                                                              cal mastoidectomy performed 34 years before.
                                                                              Audiological evaluation showed a bilateral mixed hearing
                                                                              loss with AC-PTA 73 dB and BC-PTA 44 dB in the right
                                                                              ear. Otoscopy showed a right sided discharging radical cav-
                                                                              ity, absence of meatoplasty and trapped cholesteatoma,
                                                                              while CT-scan detected a CF (Fig. 3) as well as a large (i.e.
                                                                              > 2 mm) fistula of the lateral semi-circular canal. The pa-
                                                                              tient had a hearing aid fitted ipsilaterally, because an epit-
                                                                              ympanic/mesotympanic cholesteatoma was also present in
                                                                              the left ear, with a worse hearing condition (AC-PTA 93 dB
                                                                              and BC-PTA 55 dB).
                                                                              The patient underwent revision of the right radical mastoid-
                                                                              ectomy. In order to reduce the risk of hearing loss in the
Figure 2. Patient 1. Subtotal petrosectomy of the left ear: exposed endos-    better hearing ear, the cholesteatoma matrix was preserved
teum of the scala vestibuli is visible (arrow), *footplate.
                                                                              over both the fistula sites. Postoperative audiogram showed
                                                                              unchanged right hearing. After cavity healing, the patient
scala vestibuli (Fig. 2); a white area was visible in the scala               was able to use her hearing aid. Seventeen months after
tympani, corresponding to the radiologically identified os-                   surgery, there was no evidence of recurrence or worsening
sification. At the 33-month follow-up, a diffusion weighted                   of hearing; the patient did not complain of dizziness/un-
MRI did not show any disease recurrence.                                      steadiness. She died for unrelated reasons at the age of 87.



560
                                                                                                        A five-case report on cochlear fistula




Patient 3
A 47-year-old female presented with dizziness and right
side otorrhoea. She also reported a history of right sided
hearing loss occurred after ipsilateral tympanoplasty with
mastoidectomy performed 18 years before. Otoscopy re-
vealed lateralisation of the neotympanum with small pos-
terior perforation and otorrhoea. Audiogram showed right
hearing loss with AC-PTA 60 dB and BC-PTA 26 dB. CT-
scan revealed total opacification of the right middle ear and
mastoid with erosion of the tegmen tympani/mastoideum.
The patient underwent surgical revision of the right ear
tympanoplasty.
During surgery a large cholesteatoma was identified. Its
initial removal from the middle ear cleft revealed an unu-
sually enlarged oval window niche. With this premise, a
second intraoperative analysis of CT-scan images revealed
the presence of a CF, which was undetected by the radi-
ologist and surgeon during the preoperative evaluation.
The surgical plan was then changed in favour of a radi-
cal cavity, leaving the matrix overlying the fistula in place.
Postoperative audiogram showed hearing preservation with         Figure 4. Patient 5. Temporal bone HRCT coronal view (left ear): a cochlear
                                                                 fistula can be seen on top of the promontory (arrow).
unchanged bony threshold. About 10 years later, the patient
referred ipsilateral ear fullness associated with short ver-
tigo spells and fluctuation of BC-PTA suggestive for hy-
                                                                 as the vestibule, appeared filled by fibrous and bony tis-
drops. After corticosteroid therapy the symptoms subsided.
                                                                 sue. At the last control, 42 months after surgery, diffusion
At the last clinical control, 15 years after surgery, the pa-
                                                                 weighted MRI did not show any disease recurrence.
tient did not present any disease recurrence, with the bony
threshold showing 16 dB deterioration (BC-PTA 42 dB).
The contralateral BC-PTA remained unchanged.                     Patient 5
                                                                 A 70-year-old male presented with bilateral hearing loss
Patient 4                                                        and dizziness. Left ear otoscopy showed posterior atelec-
A 27-year-old male was referred from another centre af-          tasis. Audiological examination revealed a mixed hearing
ter a mastoidectomy for an acute mastoiditis. He reported        loss with BC-PTA 39 dB and AC-PTA 65 dB. CT revealed
a history of obstruction of the right external auditory ca-      a promontory erosion associated with the presence of a
nal and progressive ipsilateral hearing loss since he was        small mass with soft tissue density in the middle ear. Con-
10 years old. Otoscopy revealed a bony mass obstructing          sidering the good residual hearing, the patient underwent
the right external auditory canal. Tonal threshold audiom-       conservative treatment, based on otological and radiologi-
etry showed right deafness and left side normal hearing.         cal follow-up. At the latest clinical control 24 months after
In CT and MRI performed before the previous mastoidec-           diagnosis, a second CT did not show any significant change
tomy, the external auditory canal, middle ear and mastoid        except for the disappearance of the small mass in the mid-
cells were occupied by material with a soft tissue density.      dle ear (Fig. 4). Hearing threshold was unchanged.
The promontorium was eroded with a CF highlighted by             On micro-otoscopic and endoscopic evaluation, it was pos-
air bubbles in the cochlear lumen. MRI also showed en-           sible to visualise the fistula as a small circular dark area
hancement of the vestibule and lateral semi-circular canal       on the promontory, posterior to the umbus (Fig. 5). Patient
extending to the whole length of the internal auditory canal.    data are detailed in Table I.
New CT and MRI were carried out with findings coincid-
ing with the previous examination, except for a complete
                                                                 Discussion
ossification of the inner ear and reduction of the enhance-
ment of the internal auditory canal. The patient underwent       Labyrinthine fistula is a common finding in cholesteatoma-
SP with complete removal of cholesteatoma secondary to           tous chronic otitis, representing around 4-12% of its com-
a huge external auditory canal osteoma. The CF, as well          plications 3,11. In a large meta-analysis, the lateral semicir-



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M. Falcioni et al.




Table I. Patient data (continues on page 563).
 p. Age       Sex            Previous                   Presenting                Disease                 Diagnosis                    CF                        CF
     (y)                        ME                      symptoms                duration (m)                                         stage *                  location
                              surgery
 1     65         F                Yes                 Otorrhoea                     84                 Cholesteatoma                   1                   Promontory
                                                           pain
                                                         vertigo
                                                        deafness
 2     85         F                Yes                   Vertigo                     120                Cholesteatoma                  1/2                  Promontory
                                                         tinnitus
                                                      hearing loss
 3     47         F                Yes                 Otorrhoea                     12                 Cholesteatoma                  1/2                  OW border
                                                        dizziness
 4     27        M                  No             Progressive hearing               204                Cholesteatoma                   3                   Promontory
                                                           loss
 5     70        M                  No                  Dizziness                     6                      COM                       1/2                  Promontory
                                                      hearing loss
ME: Middle Ear; CF: Cochlear Fistula; FU: follow-up; BC-PTA: pure-tone average of bone-conduction; LSC: Lateral Semicircular Canal; OW: Oval Window; COM: Chronic Otitis Media.
* According to Dornhoffer. In cases in which the matrix was not removed, it was impossible to precisely clarify the fistula.



cular canal was the most affected site with 87% of cases.                                  and studies including labyrinthine and cochlear fistulae at
Rarer locations include promontory (CF properly) with 8%                                   the same time.
of cases, superior semicircular canal with 6% of cases and                                 The literature only reports sporadic CF cases associated
posterior semicircular canal with 2% of cases 11. Moreo-                                   with non-cholesteatomatous chronic otitis media 4-6. This
ver, CF is frequently associated with otic capsule erosion                                 trend was confirmed by our study with 4 of 5 cases of CF
in other areas of labyrinth 12. This frequent association and                              associated with cholesteatoma.
the rarity of CF itself are the main reasons for a substantial                             Cholesteatoma can generate a fistula through 3 different
lack of specific literature on CF, with most of the articles                               mechanisms: pressure exerted by the matrix, enzymatic os-
                                                                                           teolysis and inflammation 7,13. Promontory is not a common
                                                                                           area for perimatrix substances to accumulate and consider-
                                                                                           ing its position, it is subjected to very low physical pressure
                                                                                           from overlying tissues 6. All these factors can justify the
                                                                                           rarity of CF.
                                                                                           Various classifications have been proposed for labyrinthine
                                                                                           fistulae which can be adopted for cochlear ones as well.
                                                                                           Palva and Johnnson 14 in 1986 proposed a staging system
                                                                                           based on severity of otic capsule destruction. The prelimi-
                                                                                           nary stage is the blue line: a bony erosion of the otic cap-
                                                                                           sule without a real fistula. Stage 1 is defined by exposure
                                                                                           of endosteal membrane, which remains intact. In stage 2,
                                                                                           the cholesteatoma matrix is in contact with the perilym-
                                                                                           phatic space. In stage 3, the perilymphatic space is also
                                                                                           open and the cholesteatoma involves the membranous lab-
                                                                                           yrinth directly. The main problem of this classification is
                                                                                           the impossibility to stage the fistula preoperatively relying
                                                                                           on radiologic findings only. Sometimes, in case of matrix
                                                                                           preservation when the fistula is not uncovered, it is not pos-
                                                                                           sible even postoperatively.
                                                                                           A more common classification of fistulae is by its size.
                                                                                           Sanna et al. 15 in 1986 defined 3 types of fistula based on
Figure 5. Patient 5. Otoendoscopy of the left ear: a dark area corresponding
to the cochlear fistula (arrow) is visible through the atelectasis on the promon-          dimensional criteria: small (0.5-1 mm), medium (1-2 mm)
tory, posterior to the umbus.                                                              and large fistulae (> 2 mm) as assessed by intraoperative



562
                                                                                                                                     A five-case report on cochlear fistula




Table I. Patient data (follows from page 562).
 p. Age         Associated               CF                      Disease             FU length (m)             Pre-op                 Post-op                Last FU
     (y)       labyrinthine         management                 recurrence                                    BC-PTA (dB)            BC-PTA (dB)            BC-PTA (dB)
                  fistula
 1     65             No              Complete matrix               No                     33                  Dead ear               Dead ear               Dead ear
                                         removal


 2     85            LSC            Matrix preservation             No                     17                     44                     44                     46


 3     47             No            Matrix preservation             No                     180                    26                     23                     41

 4     27            LSC              Complete matrix               No                     42                  Dead ear               Dead ear               Dead ear
                                         removal
 5     70             No                Follow-up                   No                     24                     39                      /                     39

E: Middle Ear; CF: Cochlear Fistula; FU: follow-up; BC-PTA: pure-tone average of bone-conduction; LSC: Lateral Semicircular Canal; OW: Oval Window; COM: Chronic Otitis Media.
* According to Dornhoffer. In cases in which the matrix was not removed, it was impossible to precisely clarify the fistula.



visual measurements, with consistent possible biases. The                                ontory a site where the use of the drill is exceptional, a
two classifications may overlap as larger fistulae more fre-                             iatrogenic aetiology seems unlikely.
quently involve the inner ear structures 16 which is the main                            According to the literature, CT is a reliable diagnostic tool
reason for SNHL following surgical treatment. Dornhof-                                   that is able to detect findings suggestive for labyrinthine fis-
fer 17 in 1995 published a three-point classification sys-                               tula in up to 97% of cases 19,20. Improvement in resolution
tem for labyrinthine fistulae, applied to cochlear ones as                               of CT imaging during the last 20 years has led to possible
well, and based on the degree of the labyrinth involvement.                              preoperative identification in virtually all cases. CF is detect-
Type I fistula was considered to be an erosion of the bony                               able in both axial and coronal planes, even if identification
labyrinth with an intact endosteum. A true fistula with an                               seems to be easier on coronal planes 3,6. In our series, CF
opened perilymphatic space was defined as a Type II fis-                                 was visible in scans in all cases (100%), even if the fistula
tula. Finally, an opened perilymphatic space with involve-                               located at the inferior border of the oval window was more
ment or destruction of the underlying membranous laby-                                   difficult to identify. However, because of the extreme rarity
rinth was classified as a Type III fistula.                                              of CF, radiologists and surgeons may fail to detect it during
History of vertigo is reported in about 64% of patients                                  routine imaging evaluation 5. This occurred in 1 patient of
affected by labyrinthine fistula and profound SNHL is                                    our series, when the CF was detected in the scan only after
found in 15% of cases 11. Similar data referring specifi-                                its intraoperative re-evaluation, after a suspect enlargement
cally to CF are missing in the literature. In our series, a                              of oval window was visualised during surgery. Kwon et al. 5
history of mild dizziness was reported by 3 of 5 patients                                also described a similar case in which a CF was suspected
(60%) with only 1 patient (20%) affected by severe ver-                                  during a canal-wall-up tympanomastoidectomy (CWU) and
tigo, probably related to a complete amputation of lat-                                  confirmed by intraoperative review of CT images. In addi-
eral semi-circular canal (patient 2). In addition, 2 of 5                                tion, it has to be considered that not all patients affected by
patients (40%) had a dead ear at diagnosis. Radiological                                 chronic otitis media without cholesteatoma undergo CT be-
and intraoperative findings confirmed labyrinthitis as the                               fore surgery. Redaelli de Zinis et al. 6 in 2005 published a
reason for the dead ear. The other 3 cases showed a BC-                                  case of CF diagnosed during tympanoplasty for non-chole-
PTA at diagnosis similar to the contralateral one (even                                  steatomatous chronic otitis media that was confirmed only
better in case 2). Therefore, CF may not always be ac-                                   by post-operative CT.
companied by specific ear symptoms and a high index of                                   As already reported, the majority of cases of CF present in
suspicion is required in all cases of COM 18.                                            association with cholesteatoma and require surgical treat-
It should be noted that in this series 80% of CF were                                    ment. However, the unusual occurrence of a CF in non-cho-
diagnosed in previously operated ears. However, one of                                   lesteatomatous-COM may also be managed conservatively,
these surgeries did not include any access to the middle                                 as in our patient 5. In similar cases, surgical alternatives
ear cleft (case 4); neither in the other 3, being the prom-                              can be removal of the matrix, with risk of a SNHL, or radi-



                                                                                                                                                                        563
M. Falcioni et al.




cal/modified radical mastoidectomy, which could cause a           for SNHL/anacusis consequent to a labyrinthitis, as report-
worsening of conductive component of the preoperative             ed by Palva et al. 26 and also observed by the authors in
hearing loss.                                                     2 unpublished cases.
The surgical management of labyrinthine fistula has been          This series has some limitations. No definitive conclusions
a debated issue in literature, with some authors defending        can be drawn from a series of 5 patients. In addition, clas-
a more aggressive surgical approach (matrix removal) and          sifications cannot be precisely applied to fistulas that are
others more conservative management (matrix preserva-             managed conservatively, because only matrix removal al-
tion). When surgically addressing a CF, it must be kept in        lows a clear visualisation of the actual cochlear involve-
mind that the cochlear duct is adherent to the lateral wall       ment. Despite the limitations of this study, in the authors’
of the cochlear lumen; erosion of the promontorial endos-         opinion, management of CF should be based on imaging,
teum determines direct contact between the cholesteatoma          intraoperative findings and pre-operative hearing status.
matrix and cochlear duct, exposing the latter to a high risk
of damage during any matrix manipulation. As a conse-
quence, in the presence of a CF there is a general agree-
                                                                  Conclusions
ment that matrix removal entails a higher risk of profound        CF is a rare finding and even if CT is a reliable diagnostic
sensorineural hearing loss/dead ear 1,11,21. The reported cas-    tool for its identification, it may sometimes remain unde-
es of hearing preservation are probably mainly related to         tected because of its rarity.
fistulae with preservation of the endosteal layer, an occur-      Although no definitive conclusions can be drawn from a
rence extremely difficult to predict from the CT scan. This       series of 5 patients, in the authors’ opinion, management
makes the pre-operative hearing status the most important         of CF should be based on imaging, intraoperative findings
parameter to select the appropriate surgical option.              and, most of all, pre-operative hearing status. In the pres-
In our series, 2 of 5 patients (40%) presented with anacusis      ence of a preoperative dead ear or severe to profound SN-
of the affected ear. In these cases, therapeutic choice leaned    HL, a SP may be considered the first option. In cases with
in favour of a SP 22 with complete excision of cholesteatoma,     useful BC-PTA, hearing preservation should be the main
including the fistula matrix. In both cases, CFs were occu-       purpose of treatment. Clinical and radiological follow-ups
pied by fibrotic tissue with foci of ossifications, as sequelae   may be effective therapeutic choices for cases of CF related
of previous labyrinthitis (well documented radiologically).       to non-cholesteatomatous COM with residual hearing. In
In presence of an already dead ear, SP with external au-          the presence of cholesteatoma, matrix preservation is rec-
ditory canal closure, Eustachian tube plugging and cavity         ommended by the authors through a radical/modified radi-
obliteration reduces the chances of disease recurrence and        cal mastoidectomy, especially in the only or better hearing
cavity problems; if required, it can also be combined with        ear.
a labyrinthectomy for patients reporting severe vertigo
spells 23. As a rule, SPs need to be periodically checked
with MRI to exclude any residual cholesteatoma 24.                References
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