Ali, Heba Ibrahim

Khater, Nivan Hany

English

AJOL - African Journals Online

Alexandria Journal of Medicine 54 (2018) 197–201Contents lists available at ScienceDirectAlexandria Journal of Medicinejournal homepage: ht tp : / /www.elsevier .com/locate /a jmeOtosclerosis and complications of stapedectomy: CT and MRI correlationhttp://dx.doi.org/10.1016/j.ajme.2017.07.0012090-5068/ 2017 Alexandria University Faculty of Medicine. Production and hosting by Elsevier B.V.This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Peer review under responsibility of Alexandria University Faculty of Medicine.⇑ Corresponding author.E-mail addresses: Hebaali_m@hotmail.com (H.I. Ali), Nivan_khater@yahoo.com(N.H. Khater).Heba Ibrahim Ali ⇑, Nivan Hany KhaterAin Shams University Hospital, Radiology Department, Egypta r t i c l e i n f oArticle history:Received 19 February 2017Revised 19 June 2017Accepted 2 July 2017Available online 10 August 2017a b s t r a c t 2017 Alexandria University Faculty of Medicine. Production and hosting by Elsevier B.V. This is an openaccess article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Contents1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1972. Materials and methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1982.1. Patients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1982.2. Imaging technique. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1982.3. Images interpretation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1983. Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1984. Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1985. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200Conflict of interest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2011. IntroductionOtodystrophy of the otic capsule or what is known as otosclero-sis (OS) is seen located in the majority of patients in the anterioraspect of the oval window or what is known as the fissula ante fen-estrum.1 Patients usually present between the ages of 10 and 40with hearing loss whether conductive, sensorineural or mixedhearing loss; depending on the type of otosclerosis.2 There aretwo types of otosclerosis; fenestral and retrofenestral. The classicalclinical findings are an intact tympanic membrane with no signs ofmiddle ear inflammation, progressive conductive hearing loss(CHL) and absent stapedial reflexes.3–7Usually, clinicians do not proceed to imaging those patientswith the typical clinical picture. A Stapedectomy with stapes pros-thesis is the treatment of choice for fenestral otosclerosis.3–7Since its introduction into otology, the computed tomographic(CT) scan has been shown to be a useful instrument for diagnosisof otosclerosis.3 Many studies found a reliability of more than90% in the diagnosis of otosclerosis.3The temporal bone is fully imaged with no need for intravenouscontrast material. Axial images best demonstrate the lucent spon-giotic fenestral otosclerotic foci because of the location of the foot-plate of stapes as well as that of the oval window.2Stapedectomy usually involves stapes prosthesis insertion in anaim to improve hearing by removing the fixed stapes bone andreplacing it with a microprosthesis. Prosthesis insertion may belinked to a few built-in problems such as outward displacementor inward protrusion of the prosthesis into the vestibule, granu-loma development to the more serious complications as labyrinthi-tis or perilymphatic fistulas. HRCT is the modality of choice as itaccurately shows the position of the prosthesis and helps toexclude other complications mentioned above. Because of thehyperdensity of the prosthesis, it can be easily identified on HRCT.However, MRI may be needed as a supplementary study to excludelabyrinthitis or fibrotic changes within the labyrinth.4,5,8–10198 H.I. Ali, N.H. Khater / Alexandria Journal of Medicine 54 (2018) 197–201Aim of this study is to assess the importance and utility of bothCT and MRI in the evaluation of poststapedectomy complicationsand to properly select the right imaging modality according tothe suspected clinical postoperative complication.2. Materials and methods2.1. PatientsFrom September 2015 to July 2016, we evaluated twentypatients; including 12 females and 8 males, aged 31–64 yearsold, with a mean age of 47.5. They were all referred from theENT surgical department. All are known cases of otosclerosis withhistory of stapedectomy, ranging from 4 weeks to 2 years ago.Their clinical presentation included hearing loss (8 cases), vertigo(7 cases) and routine follow up (5 cases). Onset of symptoms ran-ged from 4 weeks following the operation to up to 2 years later.CT was done for all the 20 patients followed by an MRI study foronly two patients where CT showed no well-defined cause andlabyrinthitis was suspected. CT/MR diagnosis was correlated withthe clinical diagnosis and the operative findings as the standardof reference. The study was supported by the ethical board of ourinstitution.2.2. Imaging techniqueMDCT examinations were performed with Siemens SomatomDefinition Flash, 128 slice combined with Advantage WorkstationGE; parameters consisted of a voltage of 120 kV, a current of240 mA, FOV 16cm, pitch/speed 1, and a rotation time 1, no gantrytilt: 0, slice thickness 0.4 mm at 0.4 mm interval, patient position:supine. No intravenous contrast was given to the patients in theroutine study. Acquisition of ultra-thin axial cuts was done usinga multidetector CT machine, with reformats taken in both coronaland sagittal planes with respect to the lateral semicircular canal.MRI was done for only 2 patients around 5–7 days after CT imag-ing. Stapedectomy is not a contraindication for doing an MRI.MRI was performed on a 3 T unit. The conventional T1 and T2weighted sequences were done with a slice thickness of 2 mm.Both axial as well as coronal planes were taken, for better spatialassignment. T1- weighted sequence following IV contrast adminis-tration was also acquired. A 3D high resolution heavily T2weighted submillimetre was then followed to allow evaluation ofFig. 1. Two different patients with vertigo and dizziness postoperative to stapes surgprotrusion of the prosthesis superior to 2 mm (arrows).the facial vestibulo-cochlear nerve complex and for detection ofalterations in the labyrinth.2.3. Images interpretationAll images were reviewed and analyzed by two radiologists. CTinterpretation included a comment on the position of the stapesprosthesis for either migration or protrusion, exclusion of perilym-phatic fistula and labyrinthitis ossificans as well as middle earassessment for any soft tissue lesions. MRI interpretation includedevaluation of T1 and T2 signal intensity as well as postcontrastenhancement of the membranous labyrinth.3. ResultsA total of 20 symptomatic patients poststapedectomy weresubmitted for Multidetector CT examination with 2 of the casesfollowed by an MRI study. Seven (35%) patients showed medialmigration of the prosthesis into the vestibule (Fig. 1). Six (30%)patients were diagnosed as outward protrusion of the prosthesis(Fig. 2). Two patients (10%) showed a perilymphatic fistula(Fig. 3). Three patients (15%) had a lesion in the oval windowregion (Fig. 4). Two patients (10%) showed signs of labyrinthitisdiagnosed on MRI (Fig. 5). The radiological results were in concor-dance with the intraoperative findings.4. DiscussionOtosclerosis is a disease resulting in various foci of bone resorp-tion involving the otic capsule region and is characterized by thepresence of demineralization in the active phase followed by scle-rosis in remission.11–13 The recommended surgical procedures forotosclerosis are Stapedotomy or stapedotomy.17Stapedectomy involves the insertion of a stapes prosthesis aim-ing to restore ossicular chain linkage. A variety of different stapesprosthesis are available, with different materials used as Teflon,stainless steel and platinum; all of which are of variable hyperden-sities on CT.15 80% of the causes for surgical revision are due to sur-gical failure, which is why imaging following the operation isextremely essential in the therapeutic decision. Least encounteredcomplications are the labyrinthine complications reaching to lessthan 20%. Main complications following surgery are: prosthesisdisplacement, fibrosis of the oval window, incudo-mallear disloca-tion, and obliterative otosclerosis.1ery. (A) Coronal CT reformatted and (B) axial CT images showed intravestibularFig. 2. 55 years old male presented with CHF 6 months after stapes surgery.Coronal reformatted CT images showed outward and inferior displacement of thestapes prosthesis seen between the oval window and prosthesis (arrow).H.I. Ali, N.H. Khater / Alexandria Journal of Medicine 54 (2018) 197–201 199Temporal bone CT examination can identify many complica-tions of stapes surgery; especially prosthesis dislocation and graftretraction. Postoperative otitis media and injury of the tympanicmembrane are frequently seen with few cases of cholesteatomaformation being reported as a complication followingStapedectomy.15MR examination, on the other hand, may reveal inner ear com-plications as an intralabyrinthine hemorrhage, intravestibularextension of a granuloma or inflammatory labyrinthitis.15 Ourstudy showed more prevalent complications among females,which is in agreement with Maria et al.17Position of the prosthesis; whether intravestibular bulging oroutward protrusion has been reported as the most common com-Fig. 3. Postoperative vertigo and sensory neural hearing loss in a 52 year old female patieshowed deep intravestibular protrusion of the prosthesis with evidence of pneumolabyplication. CT can easily diagnose intravestibular protrusion of theprosthesis- a bulge of the tip of prosthesis more than 2 mm intothe vestibule is highly diagnostic.4 In our study, 55% of the caseswere due to prosthesis displacement- 30% of them had medialmigration of the prosthesis into the vestibule whereas 25% hadoutward protrusion into the middle ear cavity. Our findings arein agreement with Feldman et al.18 and Han et al.19 The incidenceof occurrence of perilymphatic fistula following Stapedectomy isquite rare, ranging from 3 to 10%.20Air bubbles seen within the vestibule or even a few bubblesseen adjacent to the prosthesis (pneumolabyrinth) is highly suspi-cious, especially if associated with a fluid-filled middle ear cavity.21In our study, we encountered only 2 cases out of the 20 (10%)which showed few air bubbles adjacent to the prosthesis particu-larly the tip on CT. Findings were confirmed on surgery.Granulation tissue formation may result in recurrent CHL andif visualized at the oval window niche is known as a reparativeor postoperative granuloma. Granulation tissue is seen as softtissue attenuation; however small size, suboptimal technique,and/or motion may limit visualization. Three of our casesshowed a small well-defined round lesion within the oval win-dow by CT; one of which showed suspected intravestibularextension as well. One of the severely encountered complicationsof stapedectomy is suppurative labyrinthitis, as infection couldspread intracranially resulting in serious complications asmeningitis.22Two of our cases showed no well-defined cause by CT inspite ofpersistent SNHL. MRI was thus followed and they were diagnosedas early labyrinthitis by the presence of enhancement of the mem-branous labyrinth on the postcontrast sequence. Labyrinthitis maybe suggested late in the course of the disease if CT shows increaseddensity within the labyrinth, irregularity or obliteration of thelabyrinth.22 There were no suspected cases of postoperativecholestaetomas in our study.Fortunately, complications of stapedectomy are not commonlyseen, reaching up to only 1%.10CT is the most important imaging modality to be done followingoperation as most of the complications are diagnosed by CT. Thethin cuts taken allows accurate and clear identification of all thent following stapedectomy. (A) Axial CT and (B) coronal MPR CT reformatted imagesrinth (arrows).Fig. 5. Patient presented with intermittent tinnitus and vertigo 2 weeks post stapedectomy. (A) coronal reformatted pre-contrast T1 WI and (B) coronal reformatted postcontrast T1 WI showed bilateral intense post contrast enhancement in the lesion of both oval window and vestibule on the left side; suggestive of early labyrinthitis (arrows).Incidentally noted bilateral middle ear effusion.Fig. 4. Dizziness and vertigo in a 35 year-old the female after stapes surgery. (A) Coronal CT reformatted and (B) axial reformatted CT images showed a nonspecific soft tissuemass around the tip of the prosthesis and in the oval window niche suggestive of an intravestibular granuloma (arrows).200 H.I. Ali, N.H. Khater / Alexandria Journal of Medicine 54 (2018) 197–201middle ear complications encountered postoperatively as prosthe-sis location and presence or absence of a reparative granuloma.Even progression of the otosclerosis can be diagnosed by CT alone.On the other hand, MRI is rarely performed and used for onlythose cases where labyrinthine complications are suspected andwhich usually occur secondary to intravestibular migration of theprosthesis, labyrinthitis or intravestibular hemorrhage. Anothercomplication diagnosed by CT but which can be confirmed byMRI is the presence of a perilymphatic fistula.SNHL may appear immediately following surgery or over yearslater; with vertigo being the main complaint in patients with pro-found SNHL. Revision Stapedectomy is required in these cases.20 Inthose patient’s with deteriorated cochlear function followingstapes surgery, many studies stressed the need for emergency sur-gical revision to avoid permanent deafness.20In our study, CT and in few of the cases MRI, were of great helpto the surgeons and helped determine the cause of failure of thestapedectomy procedure; allowing further management and inter-vention. We had some limitations in our study, which included thelimited number of the study population and lack of long-term fol-low up after diagnosis and surgical revision.5. ConclusionComplications following stapedectomy are uncommon, butrequire urgent management in some cases. CT is the primary imag-ing modality for evaluating those patients with clinical complaintspoststapedectomy and who may require revision surgery. MRI maybe further on needed if CT was inconclusive.Conflict of interestThe authors declared that there is no conflict of interest.urnal of Medicine 54 (2018) 197–201 201References1. Naggara O, Williams T, Ayache D, et al.. Imaging of postoperative failures andcomplications in stapes surgery for otosclerosis. J Radiol. 2005;86:1749–1761.2. Purohit Bela, Hermans Robert, de beeck Katya Op. Imaging in otosclerosis: apictorial review. Insights Imaging. 2014;5:245–252.3. Valvassori GE. Imaging of otosclerosis. Otolaryngol Clin North Am.1993;26:359–371.4. Schwartz JD, Mukherji SK. The Inner Ear and Otodystrophies. Imaging of theTemporal Bone. Thieme: New York; 2009. 298–411.5. Hutchins T. Otosclerosis, Diagnostic Imaging Head and Neck. 2nded. Manitoba: Amirsys; 2011.6. Lee TC, Aviv RI, Chen JM, et al.. CT Grading of otosclerosis. AJNR Am J Neuroradiol.2009;30:1435–1439.7. Naumann IC, Porcellini B, Fisch U. Otosclerosis: incidence of positive findings onhigh resolution computed tomography and their correlation to audiological testdata. Ann Otol Rhinol Laryngol. 2005;114:709–716.8. Picuth D, Brandt S, Berghaus A, et al.. Vertigo after stapes surgery: the role ofhigh resolution CT. Br J Radiol. 2000;73:1021–1023.9. Kosling S, Bootz F. CT and MR imaging after middle ear surgery. Eur J Radiol.2001;40:113–118.10. Thomas JP, Minovi A, Dazert S. Current aspects of etiology, diagnosis andtherapy of otosclerosis. Otolaryngol Pol. 2011;65:162–170.H.I. Ali, N.H. Khater / Alexandria Jo11. Paz Cordovés A, Leyva Montero E, García de Hombre AM, Prieto Zelaya GM. Earsurgery outcomes in patients operated on for otosclerosis. Acta OtorrinolaringolEsp. 2007;58:79–82.12. Raut VV, Toner JG, Kerr AG, Stevenson M. Management of otosclerosis in theUK. Clin Otolaryngol. 2002;27:113–119.13. Ranghearda Anne-Sophie, Marsot-Dupucha Kathlyn, Marka Alexander S, et al..Postoperative complications in otospongiosis: usefulness of MR imaging. AJNR.2001;22:1171–1178.14. Bernardo Maria Teresa, Dias Joana, Ribeiro Daniela, et al.. Long term outcome ofotosclerosis surgery. Otorhinolaryngology. 2012;78:115–119.15. Feldman BA, Schuknecht HF. Experiences with revision stapedectomyprocedures. Laryngoscope. 1970;80:1281–1291.16. Han WW, Incesulu A, Mckenna MJ, et al.. Revision stapedectomy intraoperativefindings results and review of the literature. Laryngoscope.1997;107:1185–1192.17. Mokhtarinejad F, Roozbahany NA, Ajami M. Bilateral hearing loss followingunilateral stapes surgery. J Hearing Sci Otolaryngol. 2015;1:25–28.18. Wiet RJ, Harvey SA, Bauer GP. Complications in stapes surgery: options forprevention and management. Otolaryngol Clin North Am. 1993;26:471–490.19. Matz GJ, Lockhart HB, Lindsay JR. Meningitis following stapedectomy.Laryngoscope. 1968;78:56–63.

Otosclerosis and complications of stapedectomy: CT and MRI correlation

https://www.ajol.info/index.php/bafm/article/download/178919/168285

Otosclerosis and complications of stapedectomy: CT and MRI correlation

Abstract

Similar works

Full text

Available Versions

AJOL - African Journals Online