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- 伊海金副主任医师 博士后
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医院:
北京天坛医院
科室:
耳鼻喉科
- The diagnosis and surgical treatment of occult otogenic CSF leakage
- 作者:伊海金|发布时间:2012-10-31|浏览量:576次
Acta Oto-Laryngologica, 2012; Early Online, 1?6 ORIGINAL ARTICLE
The diagnosis and surgical treatment of occult otogenic CSF leakage H.J. YI1,2,Introduction
Otogenic cerebrospinal fluid (CSF) leakage is defined as abnormal communications between the subarachnoidal space and air-containing spaces of the temporal bone [1]. The clinical presentation depends on the anatomic integrity of the tympanic membrane and the functional status of the eustachian tube. A nonintact membrane leads to otorrhea; therwise, rhinorrhea is more likely. CSF leakage of otogenic origin can be acquired, congenital or spontaneous [2,3]. Acquired CSF leakage is caused mainly by skull trauma [2].北京天坛医院耳鼻喉科伊海金
Congenital leakage is most often associated with the development of anomalous transcranial pathways [2]. Otogenic CSF leakage can usually be diagnosed before the development of meningitis as its complication, but in rare cases of occult or intermittent CSF leakage, it is often misdiagnosed [4] until meningitis develops. This study evaluated the haracteristics of clinical presentation and the management of occult otogenic CSF leakage, including traumatic and congenital cases, which were all misdiagnosed and accompanied by meningitis on at least one occasion.
Correspondence: S.M. Yang, Department of Otolaryngology, Head and Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, PR China. Tel: +86 10 6821 1696.
E-mail: yangsm301@263.net
and P.N. Liu, Department of Neurosurgery Division 9 and Otolaryngology-Head Neck Surgery, Beijing Tiantan Hospital, Capital University of Medical Science,
Beijing 10050, China. Tel: +86 10 67096865. E-mail: pinanliu@yahoo.com.cn
(Received 20 May 2012; accepted 13 August 2012)
ISSN 0001-6489 print/ISSN 1651-2251 online 2012 Informa Healthcare
DOI: 10.3109/00016489.2012.727468
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Material and methods
A retrospective chart review examined 11 patients treated in our department from 2007 to 2012. Nine patients had traumatic CSF leakage of otogenic origin and two had congenital CSF leakage. The 11 patients were all misdiagnosed and experienced meningitis one or more times. In the authors’ hospital, both rhinorrhea and otorrhea were proved to contain
CSF (glucose content >1.7 mmol/l) by laboratory tests. Data were collected from office and hospital charts regarding patient demographics, including age, gender, comorbid conditions, time from trauma to meningitis attack, and number of episodes of meningitis. Data were also accumulated on preoperative diagnostic tests, including laboratory tests, preoperative audiograms, and imaging. Finally, information was recorded regarding surgical approach, length of postoperative follow-up, postoperative complications, postoperative audiograms, and recurrence (Table I).
Results
Characteristics of clinical presentation and imaging studies The main clinical presentations of those patients, including medical history, interrupted rhinorrhea or otorrhea, whether accompanied by intermittent fever or headache, conductive hearing loss, sensorineural hearing loss, total deafness, time from trauma to meningitis attack, and number of episodes of meningitis are all shown in Table I. The imaging studies including high-resolution noncontrast CT (HRCT), CT cisternography, and MRI can help to determine the site of the defect. These results are also shown in Table I.
Surgical approach
The selection of surgical approach for repair was based on several factors including the location of the temporal bone defect, presence of a recurrent leak, and surgeon’s preference. For the eight cases of traumatic CSF leakage we adopted the transmastoid approach to repair the leakage by the bathplug method. After the leakage of the dura was
exposed, muscle with fascia that was larger in size than the leakage was dressed and the suture was passed through it along its long axis. The muscle that the fascia was above was plugged under the dura through the leakage, the suture was pulled tight, and the leakage was sealed completely according to the bath-plug theory. Then we closed the bone defect with bone chips and tamped the mastoid cavity with Table I. Patient demographics.
Etiology of CSF leakage Gender Age (years)
Clinical presentation
Time from trauma to meningitis episode No. of episodes of meningitis
Preoperative audiograms Leakage site Surgical approach Complications
Traumatic Female,
n = 8; male,
n = 1
15?54;
average = 32
Rhinorrhea, n = 7;
otorrhea, n = 2;
headache, n = 6;
fever, n = 5;
chronic cough,
n = 5
3?11; average =5 1?3; average = 1.7 CHL, n = 3;
SNHL, n = 5;
TD, n = 1
ET, n = 2; TAT,
n = 4; PA, n = 2;
IEF, n = 1
Transmastoid
approach, n = 8;
packing the
vestibule, n = 1
None
Congenital Female,
n = 2
1.5?24;
average = 12.75
Rhinorrhea, n =2 1?10; average = 5.5 3; average = 1.5 TD, n = 2 Lateral end
of IAC
Translabyrinthine
approach, n = 2
Temporary
facial palsy, n = 2
CHL, conductive hearing loss; ET, epitympanum tegmen; IAC, internal acoustic canal; IEF, inner ear fracture; PF, posterior fossa; SNHL, sensorineural hearing loss; TAT, tympanic antrum tegmen.
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abdominal fat; the tympanic antrum was sealed at the same time. One CSF leakage with inner ear fracture was repaired by packing the vestibule with muscle and fascia. For congenital leakage, we chose the translabyrinthine approach to repair the defect. After resection of the labyrinth, which was very thin and easy to open, the vestibular cavity was opened. The media part of the vestibular cavity can be observed, but of course it was absent. Then the leakage of the dura could be observed in the internal acoustic canal (IAC) and also CSF from the leakage. Thus, the leakage could be repaired directly with muscle and fibrin glue. The temporal cavity was filled with abdominal fat and the tympanic antrum was sealed at the same time.
Postoperative course
The average length of follow-up was 3 years. No postoperative infections occurred. Drainage of CSF by lumbar puncture was not carried out. Recurrent leakage did not occur in this study. The preoperative audiograms of two cases of congenital leakage showed total deafness. When preoperative and postoperative audiograms of cases with traumatic CSF eakage were compared, conductive hearing thresholds were found to improve in three of these patients and sensorineural hearing loss in five remained unchanged. One patient
was totally deaf because of inner ear fracture (Table I).
Discussion
The etiology and characteristics of the clinical presentation can supply important diagnostic clues as regards occult otogenic CSF leakage. We first consider traumatic CSF leakage of otogenic origin. CSF leakage occurs in 2?3% of patients with head injury or 17% of patients with traumatic temporal bone fractures [5]; 60% of CSF leakage occurs within days of the trauma, and 95% within 3 months [6]. At least 85% of cases of post-traumatic CSF leakage have post-traumatic rhinorrhea and almost all cases of post-traumatic rhinorrhea will stop on their own within 1 week [7]. However, sometimes in rare cases, CSF leakage where the symptoms were occult, delayed or intermittent was often misdiagnosed and
then meningitis, the potentially fatal complication, attacked. In the present study, nine cases of traumatic CSF leakage all had temporal bone fracture and in all cases the CSF leakage was misdiagnosed until meningitis developed. We think the reason may be that post-traumatic formation of a dural scar prevents leakage of CSF but does not always provide a sufficient barrier against bacteria. As a result of atrophy of the tissue at the site of the dural lesion and microtrauma, CSF rhinorrhea can develop many years later [8]. Furthermore, the leakage may be intermittent and if the other symptoms related to CSF leakage were also occult they may mislead the doctor.
The main clinical presentation of those patients was interrupted rhinorrhea or otorrhea, accompanied by intermittent fever or headache, conductive hearing loss, sensorineural hearing loss, even total deafness in the present study. All patients experienced one or several episodes of meningitis. The time from occurrence of CSF leakage to meningitis attack was 5 years on average. The patients with rhinorrhea may present a chronic cough, especially during the night, and sometimes they may be misdiagnosed as having secretory otitis media or asthma, and otorrhea may be misdiagnosed as otitis media.
So, in patients with a history of head injury, whether 1 month or 10 years earlier, if they present repeatedly with otorrhea or rhinorrhea, intermittent fever or headache, chronic cough and without a history of media otitis, especially when companied by meningitis, CSF leakage should be considered and further tests should be performed. Congenital leakage is due to labyrinthine or perilabyrinthine dysplasia or is related to anomalies located distant from the otic capsule. Malformations such as patent retromastoid canal, enlarged and patent cochlear aqueduct, patent Hyrtl’s fissure, enlarged facial nerve canal or dehiscent lamina cribrosa of the inner auditory canal are the known perilabyrinthine pathologies [9]. Cochlear dysplasia is the most common labyrinthine abnormality associated with CSF leak of temporal bone origin in children. Schuknecht [10] observed in 1980 that the most common route of CSF leakage in cochlear dysplasia was via the internal IAC. The lateral end of the IAC was dehiscent in both of our two cases of congenital leakage, which allowed
direct communication of CSF with the vestibule (see Figure 2).
The main clinical presentation was interrupted rhinorrhea with unilateral total deafness from birth. Both patients experienced one or two episodes of meningitis. The time from occurrence of CSF leakage to meningitis was 1 year and 10 years, respectively. Even if the diagnosis of CSF leakage is established, the operation may not be performed in time and then meningitis develops because many doctor lack the knowledge of inner ear dysplasia and cannot correctly locate the site of leakage. So if a patient, especially a child, presents with recurrent CSF rhinorrhea or meningitis, with unilateraltotal deafness, then imaging studies of the temporal bone should be performed. Sometimes unilateral total deafness may be the only clinical symptom Diagnosis and surgical treatment of occult otogenic CSF leakage 3 Acta Otolaryngol Downloaded from informahealthcare.com by Chinese Peoples Liberation Army on 10/29/12 For personal use only. in patients with congenital inner ear malformations before meningitis attacks and can supply important diagnostic clues.CSF leakage involving the skull base is associated with considerable morbidity and mortality and often presents a diagnostic challenge. Imaging studies are essential for determining the site of the CSF leak in the temporal bone [11]. HRCT is the initial diagnostic study of choice in all cases and may be the only imaging necessary. Other imaging studies are potentially helpful. In the nine cases of traumatic CSF leakage in the present study, HRCT determined that the defect was in the tympanic antrum tegmen (n = 4), epitympanum tegmen (n = 2), posterior fossa (n = 2), and inner ear fracture (n = 1) (Figure 1a, c). In the two cases of congenital leakage, HRCT determined the anatomic features of dilated vestibule, dysplastic semicircular canals, stapes footplate defect, and dehiscence in the lamina cribrosa of the internal auditory meatus (Figure 2a, b).
HRCT will usually identify the bony defect of the temporal bone but will not demonstrate the site of the dural tear. In this situation, CT cisternography can play an important role and can demonstrate the leak [12]. This approach can be valuable in cases where more than one potential defect exists on HRCT. However, even with CT cisternography, determination of the location of a CSF leakage is not possible in all cases [13]. Colquhoun’s study was able to identify the site of the CSF leak in 17 of 21 cases (81%) [6]. Moreover, the preoperatively described site of the dural lesion does not always agree with the intraoperative findings [14]. In the present study, CT cisternography was performed in 10 cases ? 1 case could not undergo the procedure because of young age (1.5 years) ? and detected the leaks correctly in 7 of 10 cases (Figures 1b and 2c).
MRI is noninvasive, offers excellent anatomic detail, and has no radiation risk. In addition, MRI can distinguish middle ear/mastoid encephalocele from chronic ear disease, as the CSF signal will be bright on T2-weighted images, and an encephalocele will appear contiguous with the brain [9]. In the present study, all 11 cases were accepted for MRI
scans, and we consider that this test can be regarded as an important supplemental method and can supply diagnostic information other than HRCT and CT cisternography (Figure 2b). Other important considerations are the timing of operation and the approach to repair. Bernal-Sprekelsen et al. and Cairns advised that all CSF leakage should be treated surgically as soon as possible [5,15]. However, conservative treatment is initially recommended. The rationale for this suggestion is based on the observation that 50?85% of traumatic CSF leakage occurring within 48 h after injury ceases spontaneously [16]. Misdiagnosed or recurrent CSF rhinorrhea almost never stops without operative treatment.
This is supported by recent studies showing that if a dural repair is undertaken, the risk of meningitis occurring within 10 years is reduced from 85% to 7% [17]. When rhinorrhea persists for more than 8 days, it should be treated surgically [18].
Most authors in the literature agree that the location of the CSF leak is the predominant factor to consider when selecting the surgical approach. In general, tegmen defects are operated via a middle fossa craniotomy and posterior fossa defects via an extracranial transmastoid approach [19]. The combined approach is sometimes used. Both techniques
have advantages and disadvantages. In the present study we adopted the transmastoid approach to repair the leakage with the bathplug method in eight cases of traumatic CSF leakage that had tympanic antrum or epitympanum tegmen defect and defect of the posterior fossa, and then we closed the bone defect with bone chips, tamped the mastoid cavity with abdominal fat, and obtained good results. We thought that the bath-plug method was sufficient to repair the CSF leakage and helpful to reduce the recurrence. One CSF leakage arising from
A
B
C
Figure 1. (a) Coronal high-resolution CT (HRCT) scan of the temporal bone showing a tympanic antrum tegmen defect with a traumatic cerebrospinal fluid (CSF) leak into the middle ear (white arrow). (b) Coronal CT cisternography scan of the temporal bone showing a tympanic antrum tegmen defect with a traumatic CSF leak into the middle ear (white arrow). (c) Coronal HRCT scan of the temporal bone showing an epitympanum tegmen defect with a traumatic CSF leak into the middle ear (white arrow).
4 H.J. Yi et al.
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inner ear fracture was repaired by packing the vestibule with muscle and fascia. CSF leakage is traditionally repaired with temporal fascia. This is seldom successful in cases of congenital CSF leakage in which there is rapid flow of CSF. Even repairing such defects by packing the vestibule with muscle and fascia has a 30?60% failure rate [20], and
episodes ofmeningitis have been reported after repair. In the present study, considering the long history, audiograms showing total deafness, entire absence of the fundus of the IAC, and the obviously enlarged vestibular cavity, we thought that repairing the leakage by transoval window may result in recurrence because the lateral part of the vestibular cavity including the oval window was very thin and should not be touched. Also, the labyrinth was very thin and easy to open because of the pressure of CSF in the vestibular cavity
over a long period of time, so we chose the translabyrinthine approach to repair the leakage. We think
that the advantages of the translabyrinthine approach over the traditional transoval window approach include the following. The translabyrinthine method can provide a full visual operative field and the surgeon can operate directly on the leakage of the dura.However the transoval windows method only provided limited field and the surgeon only operated
on the defect in the oval window or tamped the vestibular cavity. The translabyrinthine method preserves the lateral part of the vestibular cavity, which is important to prevent recurrence of otorrhea. Otherwise, the lateral part must be destroyed furthermore during the operation by transoval windows and the destroyed lateral part would further result the muscle tamped into the leakage to lose the supports. The disastrous meningitis may reoccur. The results after operation proved that our ideas were correct and the operative injury to the patient was slight. The facial paralysis after operation was moderate and related to the muscle and fibrin glue [11] used to tamp the leakage oppressing the initial part of the IAC segment. After drug therapy (Prednisone, 1 mg/Kg), facial paralysis was cured after 2 months.
Conclusion
The diagnosis of occult otogenic CSF is challenging and the condition can easily be misdiagnosed. If a patient presents repeatedly with otorrhea or rhinorrhea with a history of head injury and without otitis media, CSF leakage should be considered. Special clinical presentations such as intermittent fever or headache, or chronic cough can supply important
clues. Confirmation of the diagnosis should be obtained according to those clues and suitable imaging studies should be carried out before meningitis attacks. In children, if they present repeatedly with otorrhea or rhinorrhea, especially with unilateral deafness, CSF leakage resulting from inner ear dysplasia should be considered. Different surgical echniques should be adopted such as transmastoid, translabyrhithine approach or packing the vestibule to treat the CSF leakage according to different etiologies of CSF leakage and good results can be obtained.
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