LABYRINTHINE FISTULA IN CHOLESTEATOMA AND ITS MANAGEMENT-A RETROSPECTIVE STUDY

Introduction- Labyrinthine fistula is one of the most common intra-temporal complications of cholesteatoma. Objective of study is (1) to evaluate the role of CT Scan in detecting labyrinthine fistulas, (2)to establish fact that fistula grade and location have no correlation with surgical approaches(CWU Vs CWD mastoidectomy approach),(3) to study the impact on hearing after treatment of labyrinthine fistula and(4) establish a management protocol to deal with labyrinthine fistula.

Post-operative hearing among patients with labyrinthine fistula as a complication of cholesteatoma using “under water technique”

Introduction During surgery in patients with labyrinthine fistula the mandatory complete removal of the cholesteatoma while preserving inner ear and vestibular function is a challenge. Options so far have been either the complete removal of the cholesteatoma or leaving the matrix on the fistula. We evaluated an alternative “under water” surgical technique for complete cholesteatoma resection, in terms of preservation of postoperative inner ear and vestibular function. Methods From 2013 to 2019, 20 patients with labyrinthine fistula due to cholesteatoma were operated. We used the canal wall down approach and removal of matrix on the fistula was done as the last step during surgery using the “under water technique”. The pre and postoperative hearing tests and the vestibular function were retrospectively examined. Results There was no significant difference between pre and post-operative bone conduction thresholds; 20% experienced an improvement of more than 10 dB, with none experiencing a postoperative worsening of sensorineural hearing loss. Among seven patients who presented with vertigo, two had transient vertigo postoperatively but eventually recovered. Conclusion Our data show that the “under water technique” for cholesteatoma removal at the labyrinthine fistula is a viable option in the preservation of inner ear function and facilitating complete cholesteatoma removal.

“Sandwich technique” enables preservation of hearing and antivertiginous effect in cholesteatomatous labyrinthine fistula

Purpose The aim of the study was to assess hearing, surgical and clinical results of the treatment in patients with cholesteatomatous labyrinthine fistula (LF) focusing on the different techniques and materials used in the management. Methods Study group included 465 patients. Cases with LFs discovered or confirmed during surgical procedure were thoroughly analyzed. Results LFs were noted in 11.4% of all cases. Thirty-eight patients, with all follow-up data available, were included into the further analysis. Most LFs were located in the lateral semicircular canal (87%). LFs were assessed as small in 2 cases, as medium in 24 patients while 12 were described as large. Based on Dornhoffer and Milewski classification, 50% of LFs were classified as IIa, 24% as IIb, 6 LFs were very deep (type III), while 4—superficial (type I). The size and type of LF did not influence postsurgical complaints (p = 0.1070, p = 0.3187, respectively). Vertigo was less frequent in LFs treated by “sandwich technique”, especially those with opened endosteum. In 30 (79%) patients, hearing improved or did not change after surgery. Hearing outcomes were significantly better in the ears operated by means of CWU technique (p = 0.0339), in LFs with intact membranous labyrinth (p = 0.0139) and when “sandwich technique” was performed (p = 0.0159). Postsurgical bone conduction thresholds levels were significantly better in LFs covered by “sandwich method” (p = 0.0440). Conclusion “Sandwich technique” (temporal fascia–bone pate–temporal fascia) enables preservation of hearing as well as antivertiginous effect in patients with cholesteatomatous labyrinthine fistula.

Double Trouble of Double Fistulae

The complications of attico-antral type of Chronic Suppurative Otitis Media (CSOM) are severe due to underlying bone erosion. We describe a case of a 40-year-old lady with attico-antral CSOM and mastoiditis with a postauricular fistula, who underwent modified radical mastoidectomy with excision of the postauricular cutaneous mastoid fistula. Interestingly, another fistula over the dome of lateral semicircular canal was noted intraoperatively.Few reports of occurrence of postauricular mastoid fistula with a labyrinthine fistula have been documented.

Case Report: Could Hennebert's Sign Be Evoked Despite Global Vestibular Impairment on Video Head Impulse Test? Considerations Upon Pathomechanisms Underlying Pressure-Induced Nystagmus due to Labyrinthine Fistula

We describe a case series of labyrinthine fistula, characterized by Hennebert's sign (HS) elicited by tragal compression despite global hypofunction of semicircular canals (SCs) on a video-head impulse test (vHIT), and review the relevant literature. All three patients presented with different amounts of cochleo-vestibular loss, consistent with labyrinthitis likely induced by labyrinthine fistula due to different temporal bone pathologies (squamous cell carcinoma involving the external auditory canal in one case and middle ear cholesteatoma in two cases). Despite global hypofunction on vHIT proving impaired function for each SC for high accelerations, all patients developed pressure-induced nystagmus, presumably through spared and/or recovered activity for low-velocity canal afferents. In particular, two patients with isolated horizontal SC fistula developed HS with ipsilesional horizontal nystagmus due to resulting excitatory ampullopetal endolymphatic flows within horizontal canals. Conversely, the last patient with bony erosion involving all SCs developed mainly torsional nystagmus directed contralaterally due to additional inhibitory ampullopetal flows within vertical canals. Moreover, despite impaired measurements on vHIT, we found simultaneous direction-changing positional nystagmus likely due to a buoyancy mechanism within the affected horizontal canal in a case and benign paroxysmal positional vertigo involving the dehiscent posterior canal in another case. Based on our findings, we might suggest a functional dissociation between high (impaired) and low (spared/recovered) accelerations for SCs. Therefore, it could be hypothesized that HS in labyrinthine fistula might be due to the activation of regular ampullary fibers encoding low-velocity inputs, as pressure-induced nystagmus is perfectly aligned with the planes of dehiscent SCs in accordance with Ewald's laws, despite global vestibular impairment on vHIT. Moreover, we showed how pressure-induced nystagmus could present in a rare case of labyrinthine fistulas involving all canals simultaneously. Nevertheless, definite conclusions on the genesis of pressure-induced nystagmus in our patients are prevented due to the lack of objective measurements of both low-acceleration canal responses and otolith function.