Hyrtl's fissure

Cerebrospinal Fluid Otorrhea After a Routine Tympanostomy Tube Placement: A Review of the Literature on Hyrtl Fissure

OBJECTIVE

To review the literature on Hyrtl fissure (HF) and contribute our experience with a 2-year old who developed cerebrospinal fluid (CSF) otorrhea during routine tympanostomy tube placement.

METHODS

Data Sources: Pubmed and Google Scholar searches were conducted of articles in the English language literature from all time periods using the words Hyrtl, Hyrtl's fissure, HF, and tympanomeningeal fissure. Study Selection: All relevant articles were reviewed to identify cases of HF.

RESULTS

Data Extraction: Nineteen cases, including ours, are described. Patient characteristics, method(s) of diagnosis and repair, and outcomes are reported. Computed tomography and intraoperative endoscopic images from our case are included. Presentation is more common in children (66.7% of cases where age was stated, n = 10) than in adults (33.3%, n = 5), and is most commonly unilateral (89.5%, n = 17). Cerebrospinal fluid otorrhea was the most common presentation. Six were discovered after tympanostomy tube placements while 3 were identified during cochlear implant work-up or after device failure. Surgical approaches described include endaural, transcanal, retrosigmoid, postauricular, and posterior fossa endoscopic. Multiple materials including bone wax, bone pate, fascia, muscle, and tissue sealant have been used. Our case describes an endoscopic repair in a child, which was successful at a 2-year follow-up. Data Synthesis: The small number of cases limits the utility of statistical analysis (n = 19).

CONCLUSIONS

Hyrtl fissure is a rare but important entity that may be discovered when routine procedures have unexpected results. Hyrtl fissure should be included in the differential diagnosis when there is persistent clear otorrhea after a tympanostomy tube, cochlear implant misinsertion, meningitis, or unexplained middle ear effusion in an adult.

Spontaneous Congenital Perilabyrinthine Cerebrospinal Fluid Fistulas

OBJECTIVES

To report a recalcitrant spontaneous cerebrospinal fluid (CSF) fistula arising from multiple, anatomically-linked lateral skull base defects, and to review the available literature to determine optimal techniques for operative repair of congenital CSF fistulae.

METHODS

A patient with recurrent episodes of otologic meningitis was found to have a patent tympanomeningeal fissure, also known as a Hyrtl's fissure, and internal auditory canal (IAC) diverticulum that communicated with the jugular bulb. A systematic review of the literature characterized all reports of spontaneous congenital perilabyrinthine CSF leaks, and all cases of Hyrtl's fissures.

RESULTS

An 11-year-old female was referred for recurrent meningitis. Imaging demonstrated a fistulous connection between the middle ear and IAC diverticulum via the jugular foramen. Specifically, a Hyrtl's fissure was identified, as well as demineralized bone around the jugular bulb. Obliteration of the fissure was initially performed, and a fistula reformed 4 months later. Multifocal CSF egress in the hypotympanum was identified on re-exploration, and middle ear obliteration with external auditory canal (EAC) overclosure was performed. A systematic review of the literature demonstrated 19 cases of spontaneous congenital perilabyrinthine CSF leaks. In total, 6 cases had multiple sources of CSF leak and 2 had history suggestive of intracranial hypertension. All of these noted cases demonstrated leak recurrence. Middle ear obliteration with EAC overclosure was successful in 4 recalcitrant cases.

CONCLUSIONS

Repair of spontaneous congenital perilabyrinthine CSF leaks in cases demonstrating multiple sources of egress or signs of intracranial hypertension should be approached with caution. Middle ear obliteration with EAC overclosure may provide the most definitive management option for these patients, particularly if initial attempt at primary repair is unsuccessful.

The misplaced cochlear implant electrode array

OBJECTIVES/HYPOTHESIS

Evaluation of the clinical, electrophysiologic findings, the management plans of the misplaced cochlear implant electrode array and the possible causes of misplacement. Also to provide recommendations to prevent a repeat of cochlear implant electrode misplacement into abnormal sites.

STUDY DESIGN

Retrospective study.

METHODS

Pediatric cochlear implant recipients implanted from January 2012 till January 2018 whose electrode arrays were misplaced outside the cochlea into the surrounding structures.

RESULTS

Eight pediatric cochlear implant recipients, were identified to have a misplaced cochlear implant electrode array. Different sites of improper placement included one case in the eustachian tube, another one in the vestibule, one electrode array was found to be in the petrous apex lateral to the internal carotid canal, and another one in the internal auditory canal (IAC), and in three cases the electrode arrays were packed in the hypotympanum, and lastly an electrode array recoiled after perfect insertion and was found to be in the facial recess. Six cases were initially identified immediate because of their poor intraoperative implant testing which prompted imaging while in two cases, the one found in the petrous apex and the other one in the internal auditory canal (IAC) were diagnosed several months after surgery due to unsatisfactory auditory skills development or absent behavioral responses following implantation.

CONCLUSIONS

Electrode array misplacement may be due to either failure to identify the anatomical landmarks during surgery specially the infracochlear air cell track or unidentified inner ear malformation. The routine use of intraoperative electrophysiologic testing and postoperative imaging should help to avoid such complications. Misplacement is a rare but still correctable complication after cochlear implant surgery. The diagnosis of misplacement can be delayed for years and in this occasion, it is suspected when benefit from the implant is limited or absent. Once misplacement is diagnosed revision surgery has to be done.

Life-threatening unilateral hearing impairments. Review of the literature on the association between inner ear malformations and meningitis

BACKGROUND

Bacterial meningitis is a life threatening disease that can be triggered by a CSF leak through an inner ear malformation. Early identification of the specific type of cochleovestibular dysplasia and the associated risk of meningitis is of vital importance.

OBJECTIVES

The objective of this review is to collect and discuss available data on the association between inner ear malformations and meningitis in children.

METHODS

Electronic databases were crosschecked for obtaining relevant papers published in the last 20 years, and further cases were identified by hand searching through the references. Demographic data were extracted from full texts, together with information on the severity of hearing impairment, the type of inner ear anomaly, the site of cerebrospinal fluid leak, the number of recurrent meningitis episodes.

RESULTS

Sixty-seven cases of meningitis related to inner ear malformation have been identified among 45 papers. Mean age at presentation is 3.60±3.00 (range 0.1-14) years. Average diagnostic delay from the first episode of meningitis is 3.44±3.41 (range 0.00-10.00) years. The number of meningitis episodes that occurred before the correct diagnosis and definitive surgical treatment is 3.27±1.81 (range 1.00-10.00). Unilateral hearing impairment affects 70% of patients. Six patients had normal hearing at presentation. Two children are dead from inner-ear-malformation-related meningitis among reviewed reports.

CONCLUSION

A high number of paediatric patients carrying inner ear malformations, especially when associated with unilateral hearing impairment, could be at risk to develop recurrent bacterial meningitis. Universal newborn hearing screening programs should prompt a diagnostic work-up even in the case of unilateral hearing impairment, in order to prevent inner ear malformation-related meningitis.

Spontaneous resolution of cerebrospinal fluid otorrhoea in a patient with a Hyrtl's fissure

Objective:

This paper reports a rare case of cerebrospinal fluid leak due to a Hyrtl's fissure and discusses the non-operative management of the case.

Background and case report:

Cerebrospinal fluid otorrhoea is a rare phenomenon arising from an abnormal communicating tract between the subarachnoid space and middle ear. Affected patients are at a higher risk of developing meningitis and other neuro-otological complications. There are four common congenital causes of cerebrospinal fluid otorrhoea in the region of a normal labyrinth. This paper describes a case of cerebrospinal fluid in the middle ear resulting from a Hyrtl's fissure, which resolved spontaneously.

Conclusion:

A literature search indicated this to be the first case with such a resolution without the need for any intervention.

Spontaneous Cerebrospinal Fluid Otorrhea from a Persistent Tympanomeningeal Fissure Presenting as Recurrent Serous Otitis Media

We describe spontaneous cerebrospinal fluid (CSF) otorrhea through a patent tympanomeningeal (Hyrtl) fissure presenting as recurrent serous otitis media. The CSF leak was observed when a drain was placed through the tympanic membrane by an otologist. The diagnosis was then confirmed by computed tomography and magnetic resonance imaging, and the patient underwent a successful surgical treatment via a retrosigmoid approach. We describe the case and review causes of spontaneous CSF rhinorrhea/otorrhea.

The role of post-operative imaging in cochlear implant surgery: a review of 220 adult cases

OBJECTIVES

To determine the incidence of abnormal radiological findings after cochlear implantation and their effect on clinical outcomes.

METHODS

Retrospective review of 220 adult cochlear implants. Clinical records and post-operative plain X-rays were reviewed and compared with pre-operative and 6-month post-operative City University of New York (CUNY) speech scores.

RESULTS

There were no cases of extra-cochlear array misplacement. Imaging showed 20 cases of incomplete array insertion (9.2%), 3 cases of kinking of the array (1.4%), 2 cases of tip rollover (0.9%), and 1 case of apparent array fracture (0.5%). Patient management was not altered by abnormal imaging. Patients with abnormal radiological findings had slightly minor improvements (median 39 vs. 56%) in City University of New York (CUNY) speech discrimination scores at 6 months (Mann-Whitney U test, P = 0.043).

CONCLUSION

All abnormalities on post-operative imaging were minor and did not alter patient management. The future role of post-operative imaging is discussed.

Petrous apex lesions in the pediatric population

A variety of abnormal imaging findings of the petrous apex are encountered in children. Many petrous apex lesions are identified incidentally while images of the brain or head and neck are being obtained for indications unrelated to the temporal bone. Differential considerations of petrous apex lesions in children include "leave me alone" lesions, infectious or inflammatory lesions, fibro-osseous lesions, neoplasms and neoplasm-like lesions, as well as a few rare miscellaneous conditions. Some lesions are similar to those encountered in adults, and some are unique to children. Langerhans cell histiocytosis (LCH) and primary and metastatic pediatric malignancies such as neuroblastoma, rhabomyosarcoma and Ewing sarcoma are more likely to be encountered in children. Lesions such as petrous apex cholesterol granuloma, cholesteatoma and chondrosarcoma are more common in adults and are rarely a diagnostic consideration in children. We present a comprehensive pictorial review of CT and MRI appearances of pediatric petrous apex lesions.

The Management of Spontaneous Otogenic CSF Leaks: A Presentation of Cases and Review of Literature

Objective The types of otogenic cerebrospinal fluid (CSF) fistulae were previously classified into defects through, adjacent to, or distal to the otic capsule. This article presents cases of the three different types of spontaneous CSF fistulae and reviews pertinent literature. We examine the management of the different types of otogenic CSF leaks with modern audiovestibular testing, imaging, and surgical techniques. Design Case series and review of the literature. Setting Academic tertiary neurotologic referral practice. Participants Four patients identified through a retrospective search. Main outcome measures Resolution of CSF leak and absence of meningitis. Results Surgical intervention was performed on the four cases described in this series; none had a return of CSF otorrhea in the postoperative period or meningitis. Conclusions Otogenic CSF fistulae may lead to life-threatening infection and in congenital forms are typically not diagnosed unless meningitis has occurred. Rapid and proper recognition, work-up, and treatment of such leaks decrease the risk of permanent neurologic sequelae as well as recurrent meningitis.

Cochlear implant electrode misplacement: incidence, evaluation, and management

OBJECTIVES/HYPOTHESIS

To review the presentation and management of improper electrode array placement, and to help guide clinical decision-making.

STUDY DESIGN

Retrospective case series.

METHODS

Pediatric and adult cochlear implant patients managed from January 2001 to present whose electrode arrays were not placed properly within the cochlea or extended beyond the cochlea into the internal auditory canal or adjacent structures.

RESULTS

Four patients, three pediatric and one adult, were identified from over 824 cases (< 1%) managed over the study duration. All cases had normal cochlear anatomy. These cases were initially identified due to poor auditory skill development or absent behavioral responses following implantation, which prompted imaging. Two patients presented several years after surgery. Sites of improper placement included the eustachian tube, vestibule, internal carotid artery canal, and internal auditory canal (IAC). Intraoperative findings and management are reviewed.

CONCLUSIONS

Electrode array malpositioning is a rare, but serious and correctable complication in cochlear implant surgery. A multidisciplinary approach, including prompt audiologic evaluation and imaging, is important, particularly when benefit from the implant is limited or absent. Management of electrode arrays in the IAC may be more challenging.

Cerebrospinal fluid otorrhoea following grommet insertion: management using a multi-layered graft technique and an important lesson revisited

BACKGROUND

A spontaneous cerebrospinal fluid leak can sometimes only become apparent following grommet insertion and usually represents dehiscence of the tegmen tympani, which is an uncommon condition.

OBJECTIVES

This report aimed to reaffirm the importance of recognising this unusual presentation and outline management options.

CASE REPORT

A 63-year-old man with conductive hearing loss and type B (flat) tympanometry underwent grommet insertion into his left ear, which resulted in cerebrospinal fluid otorrhoea. A defect of the tegmen tympani was found. This was successfully repaired via a transmastoid approach using a multi-layered grafting technique.

CONCLUSION

Dehiscence of the tegmen tympani is uncommon and may only come to light following grommet insertion, which may be problematic for the uninformed otolaryngologist. Education is important to ensure early recognition and appropriate management.

Cochlear implant electrode array misplaced in Hyrtl's fissure

Hyrtl's fissure is a cleft that is present in the developing fetal petrous temporal bone and extends from the area inferior to the round window to the meninges of the posterior fossa. Persistent Hyrtl's fissure, due to incomplete ossification, is considered a rare temporal bone malformation, and is a known cause of perilabyrinthine cerebrospinal fluid fistula. Very few cases are reported as being at risk of complication of cochlear implant surgery. Here we report the case of an 8-year-old boy with misplacement of an electrode array in Hyrtl's fissure. The diagnosis was made postoperatively, since cochlear implant failure was suspected from non-auditory responses. Computed tomography (CT) revealed the extracochlear location of the electrode array. We emphasize the role of presurgical imaging CT and magnetic resonance imaging in detecting temporal bone abnormalities, and we discuss the value of intraoperative auditory nerve response telemetry and postoperative radiological evaluation in diagnosing cochlear implant misplacement.

Spontaneous Temporal Cerebrospinal Fluid Leak

An abnormal communication between the subarachnoid spaces and the tympanic cavity and mastoid cells can determine a cerebrospinal fluid (CSF) leak in the air spaces of the temporal bone. The etiology of CFS leak in the temporal air cells includes acquired, congenital and spontaneous causes. Spontaneous CSF leak, defined as a leak without a manifest cause, is present in about 4% of cases and often occurs in the middle cranial fossa. We describe a case of spontaneous CSF leak in the right temporal air cells that mimicked a skull fracture in a subject with headache and apparent rhinorrhea after a head trauma. Both CT and MRI play a key role in the differential diagnosis between post-traumatic temporal CSF leak due to a fracture and spontaneous leak: traumatic CSF leak often does not require a surgical approach, whereas spontaneous CSF leak may need surgical treatment because of the risk of meningitis.

Cerebrospinal Fluid Leaks of Temporal Bone Origin: Etiology and Management

BACKGROUND

Cerebrospinal fluid (CSF) leaks of the temporal bone region require surgical treatment as they pose life-threatening risks such as meningitis.

AIM

The aim of the study was to determine the surgical outcome depending on different operation techniques and grafts.

METHOD

We performed a retrospective review of 28 cases of CSF leaks, operated in our department from 1983 to 2002. After a mean follow-up of 8 years, patients were interviewed concerning otorrhea or rhinorrhea and meningitis. In this context, our management of CSF leaks is presented.

RESULTS

The CSF leak had arisen spontaneously (n = 3), traumatically (n = 6) or postoperatively (n = 19). The surgical CSF leak repairs were performed via a transmastoid (n = 13), a middle fossa (n = 11) or a combined (n = 4) approach. Surgical outcome was independent on the used graft. CSF leak could be sealed in 25 of 28 cases. Only 3 patients suffered from recurrences. Meningitis or other complications did not occur.

CONCLUSIONS

Comparing different techniques and grafts, there were no differences in the surgical outcome.

Tegmen tympani cerebrospinal fluid leak repair

OBJECTIVE

To describe the transmastoid approach for closing cerebrospinal fluid leaks in the tegmen tympani using autologous materials (temporal muscle fascia and abdominal fat) and heterologous materials (bovine collagen), together with its advantages and disadvantages.

MATERIAL AND METHODS

We present the cases of three patients who underwent closure of spontaneous cerebrospinal fluid leaks in the tegmen tympani in which we used the transmastoid approach and autologous and heterologous materials. The three patients underwent canal wall-up mastoidectomy, posterior tympanotomy, removal of the malleus head and incus and, consequently, exposure of the tegmen tympani and the cerebrospinal fluid leak. Closure was performed using temporal muscle fascia, abdominal fat and bovine collagen, fixed in place with fibrin glue. A lumbar shunt was established, as is routine.

RESULTS

The cerebrospinal fluid leak was closed in all patients using the technique described, with a minimum follow-up of 14 months.

CONCLUSION

The technique presented herein is an excellent option in cases of cerebrospinal fluid leakage in the tegmen tympani; it is easy to perform and results in minimal risk to patients.