labyrinthine fistula

7/25/2019 Labyrinthine Fistula

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LABYRINTHINE FISTULA

A labyrinthine fstula results rom the erosion o

theendohondral bone o the bony labyrinth! The loss othis

bone allo"s the underlyin# endosteum$ %erilym%h$and

strutures o the endolym%hati om%artment to mo&e "hen

the %ressure in the e'ternal!

auditory anal is han#e! (otion o the )uids in the

endolym%hati om%artment brin#s on the sym%toms o

labyrinthine fstulae! Almost all labyrinthine fstulae a*et the

lateral semiirular anal+ the su%eriorand %osterior

semiirular anals$ &estibule$ and ohlea are rarely in&ol&ed!

,holesteatoma is the ause in nearly all ases$ and fstulae

"ere seen to our in -. o the holesteatomas in /ersdor*

and Nou"en0s lar#e series!12 Hi#her %erenta#es ha&e been

re%orted$ but the atual inidene is un3no"n!

(ost re%orts o labyrinthine fstulae are rom tertiary are

reerral enters that inlude many %atients "ith lar#e or%re&iously o%erated holesteatomas$ "hih artifially ele&ates

the inidene! 4n the other hand$ studies re&ie"in#

su%%urati&e om%liations o otitis media oten do not inlude

labyrinthine fstulae i the fstula is not ineted or does not

ause si#nifant sym%toms or i the sur#eon frst detets it at

o%eration! The mehanisms by "hih a holesteatoma auses

bone erosion are not ully understood$ but the dense

endohondral bone frst beomes deminerali5ed and then is

absorbed so that a %ro#ressi&ely smaller amount o bonee'ists bet"een the endosteal membrane o&erlyin# the

%erilym%h and the holesteatoma matri' abo&e it!6hen the

bone is om%letely resorbed$ the sur#eon an see "hat

a%%ears to be a 7blue line8 %arallel to the underlyin#

semiirular anal lumen beause the illuminatin# li#ht at the


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blue line is no lon#er re)eted o* the dense bone but is

absorbed into the underlyin# )uid!

(anolidis reently re&ie"ed the reords o 111 inner9ity Te'as%atients "ith labyrinthine fstulae and loo3ed or any

oe'istin# om%liations!1: T"o assoiations "ere %rominent!

The aial ner&e "as in&ol&ed "ith holesteatoma or "as

dama#ed by the holesteatoma in ;ority o

these %atients had t"o or more o%erations$ "ith an a&era#e o

?!; o%erations %er %atient! Sur#eons should sus%et a triad o

om%liations@ lateral semiirular anal fstula$ aial ner&e

e'%osure$ and te#men erosion in all %atients under#oin#re&ision sur#ery or holesteatoma or in %atients "ith %rimary

auired holesteatomas that de&elo%ed in "ell9%neumati5ed

mastoids!

Labyrinthine fstulae ause mostly &estibular sym%toms!

atients desribe short %eriods o imbalane$ dyseuilibrium$

or &erti#o but ha&e normal euilibrium most o the time! Some

reall that they eel suddenly o* balane "hen they hear a

sudden loud sound$ "hih is alled Tullio0s %henomenon$ or

"hen they %ush on their e'ternal ear anal$ or

e'am%le$ "hen leanin# their ear "ith a "ashloth!

Ater obtainin# a history that su##ests the %resene o a

fstula$ the %hysiian should %erorm the fstula test$ a s%eif

maneu&er that an establish the dia#nosis! The e'aminer

oludes the e'ternal auditory anal "ith the %neumati

otoso%e and alternately inreases and dereases the %ressure

sli#htly so that %ressure han#es are transmitted rom the

anal to the middle ear and mastoid air ell system throu#h

either an intat or a %erorated tym%ani membrane! Curin#


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the test$ the %atient is told to loo3 diretly ahead at a s%eif

ob>et$ and the %hysiian obser&es the %atient0s eyes or any

hori5ontal de&iation! In a normal ear$ han#es in e'ternal anal

%ressure ause no motion o the eyes and no sym%toms!6hen

a lateral anal fstula is %resent$ %ositi&e %ressure transmittedrom the e'ternal auditory anal om%resses the lateral

semiirular anal endosteum and auses utriulo%etal

endolym%h )o"! This %rodues a %ositi&e fstula si#n$

on>u#ate de&iation o the eyes a"ay rom the side o the

om%ression! Ne#ati&e e'ternal auditory anal %ressure

%rodues a on>u#ate de&iation to"ard the ear bein# tested!

The %atient may beome sli#htly nauseated or %erei&e a to9

and9ro motion o the en&ironment durin# the test! 4nly DD to

-


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holesteatoma debris "ithout disturbin# the matri'$ the

sur#eon loo3s or the 7blue line8 that identifes the site o the

fstula and the thin layers o lateral semiirular anal bone on

either side! The sur#eon de&elo%s a dissetion %lane bet"een

the holesteatoma matri' and the endosteum usin# hi#hmiroso%i ma#nifation and a )at dissetor

that is ? to 2 mm "ide! The matri' is ele&ated "ith a fne

mirosution to im%ro&e &isuali5ation o the dissetion %lane! A

small %iee o tissue or a thin a% o bone is %laed o&er the

site and seured "ith fbrin #lue or %a3in# ater the

holesteatoma is suessully remo&ed! I the endosteum is

torn$ it is best to re%lae the matri' and terminate the

%roedure!

S%ontaneous &estibular sym%toms usually im%ro&e ater the

fstula is re%aired$ but sym%toms rom ear anal %ressure

han#es may %ersist or some time$ and a %ositi&e fstula si#n

"ill %ersist until there is a re#ro"th o bone o&er the site o

the fstula! The %rini%al ris3 in remo&in# the holesteatoma

matri' rom the fstula is total or %artial loss o hearin#$ "hih

ours in less than ?


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mastoid baik melalui utuh atau membran timpani berlubang . Selama pengujian ,

pasien disuruh melihat langsung ke depan pada objek tertentu , dan dokter

mengamati mata pasien untuk setiap penyimpangan horisontal . (alam telinga

normal, perubahan tekanan eksternal kanal tidak menyebabkan gerakan mata dan

tidak ada symptoms.*hen fstula kanal lateral hadir , tekanan positi ditransmisikan

dari saluran pendengaran eksternal kompres endosteum kanalis semisirkularislateral dan menyebabkan aliran endolymph utriculopetal . :ni menghasilkan tanda

fstula positi , deviasi konjugat dari mata dari sisi kompresi . ekanan kanal auditori

eksternal negati menghasilkan deviasi konjugat terhadap telinga sedang diuji .

7asien mungkin menjadi sedikit mual atau menganggap mosi untuk bolak'balik dari

lingkungan selama tes . Hanya '!0 " pasien dengan erosi kanal lateral yang

memiliki tes fstula positi, tetapi pada pasien , itu adalah indikasi yang sangat

handal yang fstula hadir dan memungkinkan ahli bedah untuk merencanakan

operasi sehingga ia dapat menghindari memasuki fstula selama operasi . Secara

tidak sengaja membuka fstula labirin biasanya menyebabkan total kerugian

mendengar bahwa ear.$ isiko utama dalam menghilangkan matriks

kolesteatoma dari fstula adalah kerugian total atau sebagian dari pendengaran ,

yang terjadi dalam waktu kurang dari 20 " kasus fstula dikelola dengan hati'hati

labyrinthine fistula

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