Surgical management of spontaneous cerebrospinal fluid leakage through temporal bone defects—case series and review of the literature

An algorithm for the surgical approach to spontaneous temporal bone CSF leak

OBJECTIVE

To suggest a comprehensive algorithm for the surgical approach for correcting of sources of temporal bone CSF leaks.

METHODS

A case series for patients operated in a single academic tertiary referral center between 2011 and 4.2022. Included in the study were 46 patients, 5 of whom had a bilateral problem, resulting in 51 pathologic temporal bones. The presentation was an active CSF leak (38 patients) or bacterial otogenic meningitis (8 patients). Follow up ranged from 8 months to 5 years.

RESULTS

Of the 42 ears operated via the default middle fossa approach, 37 were successful (88 %) in controlling CSF leak. None had intracranial complications or sensorineural hearing loss. Location, number and size of the defects, hearing status, associated superior semicircular canal dehiscence, additional intra-temporal or intra-cranial pathologies may indicate a transmastoid approach. Of the six ears that had a canal wall up mastoidectomy as a primary procedure, one required revision due to ongoing CSF leak. Five revision cases and three primary cases were effectively sealed with a subtotal petrosectomy and obliteration. One was lost to follow-up. Hearing was reconstructed with bone-anchored hearing implants in 6 out of these 8 ears.

CONCLUSIONS

The middle fossa approach could be used as a default approach for sealing TD. There are a number of indications for transmastoid approaches in both primary and revision cases. Obliteration of the ear was used in all revision cases. The suggested algorithm can help in planning surgery for temporal bone CSF leaks or a history of otogenic meningitis.

The Association Between Obesity and Spontaneous Temporal Bone CSF Leak Outcomes: A Systematic Review and Meta-Analysis

OBJECTIVE

We undertook a systematic review of the literature with meta-analysis to identify the role of obesity (BMI ≥30) in the patient characteristics presenting with spontaneous cerebrospinal fluid (sCSF) leaks of the lateral skull base and the outcomes of their repair.

DATA SOURCES

A Systematic Review of English Articles using MEDLINE, EMBASE, and Cochrane Library.

REVIEW METHODS

The research algorithm included the following keywords: "spontaneous CSF leak," "lateral skull base," "temporal bone," "meningocele," "encephalocele," and "otorrhea." We also manually searched the references of included studies, to identify possible studies missed during our literature search.

RESULTS

More than two-thirds of the patients were female (69.2%) and often were obese (mean BMI 36.5 kg/m2) with a mean age of 57. Most common presenting symptoms were otorrhea and hearing loss. Most authors did not report a routine use of a post-operative lumbar drain. Most patients had a single skull base defect and encephaloceles prolapsing through, across obese and non-obese groups. Median length of stay in hospital was 3.2 days, and the majority of patients did not have any recurrence during their follow-up (89.6%), which was not affected by obesity.

CONCLUSION

Obesity does not affect length of hospital stay or recurrence rate following surgical repair of lateral skull base sCSF leaks. Surgical repair is a safe and viable approach in the management of obese patients with sCSF leaks in the temporal bone.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:2012-2018, 2024.

Analysis of 3 Surgical Approaches for the Treatment of Cerebrospinal Fluid Otorrhea: A Case Series Report

Background: This case series report aimed to present three surgical approaches used for the treatment of cerebrospinal fluid (CSF) otorrhea, providing less invasive surgical options for managing this condition. Methods: Clinical data of 26 patients with CSF otorrhea, who underwent treatment using three surgical methods between June 2012 and June 2022, were retrospectively analyzed. The study collected information on patients' basic demographic characteristics, chief complaints, location of the defect, results of otorrhea endoscopic examination, findings from skull base thin-slice computed tomography (CT) examination, and causes of CSF otorrhea. Postoperative outcomes of CSF otorrhea were followed up. Results: Among the 26 cases of CSF otorrhea, there were 13 (50%) males and 13 (50%) females who underwent treatment using the three surgical methods. The etiology of CSF otorrhea included 10 (38%) cases of spontaneous CSF otorrhea, including 2 (8%) cases of congenital inner ear deformity and 8 (31%) cases without obvious inducement. Additionally, there were 5 (19%) cases of trauma, 6 (23%) cases of cholesteatoma complications, 3 (12%) cases of postoperative complications of brain tumor, 1 (4%) case of radiotherapy, and 1 (4%) case of a malignant tumor. A total of 12 (46%) cases of CSF otorrhea were treated by local repair of the defect. Furthermore, 3 (12%) cases underwent local repair of the defect combined with sealing of the tympanic sinus entrance, while 11 (42%) cases underwent local repair of the defect combined with sealing of the eustachian tube and the external auditory canal. No recurrence of CSF otorrhea was observed during the 6-month to 10-year follow-up period after surgery. Conclusion: The three methods for CSF otorrhea, including local defect repair, local defect repair combined with sealing of the tympanic sinus entrance, and sealing of the eustachian tube and the external auditory canal, demonstrated successful outcomes in appropriately selected patients.

Surgical management of spontaneous middle cranial fossa defects: a systematic review and meta-analysis of available reconstructive techniques and materials

Different materials and techniques have been proposed for surgical repair of spontaneous middle cranial fossa (MCF) defects. However, conclusive evidence supporting their selection and impact on clinical outcomes is lacking. The study aims to conduct a systematic review and meta-analysis on materials and techniques employed to repair MCF defects and evaluate complications and rates of recurrent cerebrospinal fluid (CSF) leaks. A PRISMA-guided systematic review and meta-analysis were performed using MESH terms and specific keywords including studies published before May 2022. Primary outcomes included recurrence of CSF leak and complication rates by type of reconstructive material and technique utilized. Meta-analyses of proportions were performed using random effects and confidence intervals for individual proportions were calculated using the Clopper-Pearson method. Twenty-nine studies were included (n = 471 cases). Materials employed for repair were categorized according to defect size: 65% of defects were of unknown size, 24% were small (< 1 cm), and 11% were large (≥ 1 cm). Rigid reconstruction (RR) was significantly favored over soft reconstruction (SR) for larger defects (94% of cases, p < 0.05). Complications and recurrent CSF leak rates of SR and RR techniques were comparable for defects of all sizes (p > 0.05). Complication rates reported for these procedures are low regardless of technique and material. RR was universally preferred for larger defects and analysis of complication and recurrence rates did not reveal differences regardless of defect size. While RR was more frequently reported in smaller defects, SR was used by several centers, particularly for smaller MCF floor defects.

A Case of Gorham-Stout Disease Treated with Fistula Closure by Transmeatal Approach

Gorham-Stout disease, a rare and intractable disease of unknown etiology, causes systemic bone lysis and replacement with lymphoid tissue. Here, we report a case of Gorham-Stout disease with cerebrospinal fluid leakage in a 16-year-old boy. The patient complained of nasal discharge, right ear obstruction, fever, and headache. A computed tomography scan of the head showed osteolysis around the right internal carotid artery, vestibule, and cochlea and osteolytic changes in the left parietal bone. It was suggested that the patient had bacterial meningitis owing to the leakage of cerebrospinal fluid from the fistula caused by the temporal bone osteolysis. He was treated with meropenem, and a transmeatal fistula closure and a bone biopsy of the left parietal bone were performed. Intraoperatively, osteolysis was observed on the promontory and around the internal carotid artery. The fistula was closed by dense filling and compression around the fistula, in the middle ear cavity, and in the external auditory canal. The symptoms disappeared after the surgery. Bone biopsy showed the presence of a lymphangioma, and Gorham-Stout disease was diagnosed. Prophylactic bisphosphonate therapy was initiated. A 4-year follow-up revealed no progression of the disease.

Middle Fossa Encephaloceles Treated via the Transmastoid Approach: A Case Series and Review of the Literature

BACKGROUND

Middle fossa (MF) encephaloceles are rare lesions resulting from herniation through defects in the tegmen tympani or mastoideum. Underlying etiologies and clinical presentations are variable. Surgical goals include fistula obliteration, resection of nonfunctioning parenchyma, and dehiscence repair. The middle cranial fossa approach (MCFA), transmastoid approach (TMA), and combined (MCFA + TMA) approaches have been described. The minimally invasive TMA provides excellent exposure of the pathology and allows for ample working room to repair the defect.

OBJECTIVE

We present short-term follow-up results in patients treated via the TM repair at our institution.

METHODS

A retrospective review of patients with symptomatic encephaloceles treated via the TMA by our multidisciplinary team. Patient demographics, clinical presentations, intraoperative findings, repair technique, and outcomes were highlighted.

RESULTS

A total of 16 encephaloceles in 13 patients were treated. Defect etiologies included spontaneous (50.0%), secondary to chronic infection (25.0%), or cholesteatoma (18.8%). Defects were most often within the tegmen mastoideum (68.8%). Average length of surgery was 3.3 h (95% CI: 2.86-3.67) and length of stay 3.9 d (95% CI: 3.09-4.79). On short-term follow-up (average 11.5 mo), no patients experienced postoperative cerebrospinal fluid leak or recurrence. The majority of patients (83.3%) experienced confirmed improvement or stabilization of hearing.

CONCLUSION

MF encephaloceles present with various clinical manifestations and result from multiple underlying etiologies. The TMA is an alternative to craniotomy and our short-term results suggest that this approach may be utilized effectively in appropriately selected cases.

Middle Cranial Fossa Approach to Repair Tegmen Dehiscence Using Self-setting Calcium Phosphate Cement: A Retrospective Case Review

OBJECTIVES

To review the outcomes of repairing tegmen dehiscence using the middle cranial fossa approach with a self-setting bone cement.

STUDY DESIGN

Retrospective case series.

SETTING

Two academic tertiary hospitals.

PATIENTS

All patients presenting for surgical repair of tegmen dehiscence and with postoperative follow-up for at least 6 months between October 2015 and July 2019.

INTERVENTION

Surgical repair using a middle cranial fossa approach using a layered reconstruction with temporalis fascia and self-setting calcium phosphate bone cement.

MAIN OUTCOME MEASURES

Perioperative complications, recurrence of presenting symptoms/disease, hearing, and facial nerve grade.

RESULTS

The cohort consisted of 22 patients with 23 tegmen dehiscence repairs (1 sequential bilateral repair). There were 16 males and 6 females with an average age at operation of 52.6 years. Repairs were left sided in 9, right sided in 12 patients, and bilateral in 1 patient. No patients had recurrence of presenting symptoms or disease at most recent follow-up. Preoperative hearing was maintained in all patients. Two patients (9% of repairs) experienced delayed partial temporary facial nerve weakness House-Brackman grade 2 and 4 which had recovered by 8 weeks postoperative.

CONCLUSION

We demonstrate a technique for repairing tegmen dehiscence of the middle cranial fossa floor that has excellent postoperative outcomes. We highlight potential technical challenges in this approach as well as the need for counseling for potential partial transient facial nerve dysfunction.

Petrous Apex Cephaloceles: Radiology Features and Surgical Management of a Rare Entity

OBJECTIVE

To characterize the radiologic findings of petrous apex cephalocele (PAC) in a patient cohort, and report the surgical management for three symptomatic PAC patients and cerebrospinal fluid (CSF) leak via the middle cranial fossa approach.

STUDY DESIGN

Retrospective case series.

SETTING

Academic center.

PATIENTS

Thirty-five patients with PAC were identified by review of the imaging archive between 2008 and 2019 (29 females; mean, 55 yrs; range, 4-86 yrs). All patients underwent magnetic resonance imaging of the skull base and/or computed tomography examination.

INTERVENTIONS

Surgical repair of PAC.

MAIN OUTCOME MEASURES

Radiologic features of PAC.

RESULTS

Radiological features of PAC: 25.7% bilateral; partial or expanded empty sella in 82.9%; arachnoid pits in 14.2%; and enlarged CSF space of optic nerve sheath in 20.0%. Coexisting pathology included temporal, sphenoid, and bilateral jugular foramen meningocele; as well as cribriform, middle crania fossa, and right temporal defect. Three case studies describing the surgical course of spontaneous CSF leak secondary to PAC were managed with the middle cranial fossa approach.

CONCLUSIONS

PAC is an exceedingly unusual cause for CSF leak in the adult and pediatric population. A middle fossa approach may be used to treat CSF leak as a result of PAC. Typically, CSF otorrhea originates from an encephalocele that extends via a bony defect in the tegmen tympani or tegmen mastoideum. However, on occasion the source of the CSF otorrhea is not via the tegmen, instead defects in the middle fossa floor, medial to the ridge for the gasserian ganglion (tubercle of Princeteau), need to be considered.

Radiological findings in spontaneous cerebrospinal fluid leaks of the temporal bone

BACKGROUND AND OBJECTIVE

Spontaneous cerebrospinal fluid leak of the temporal bone is an emerging clinical entity for which prompt and accurate diagnosis is difficult given the subtle signs and symptoms that patients present with. This study sought to describe the key temporal bone abnormalities in patients with spontaneous cerebrospinal fluid leak.

METHODS

A retrospective cohort study was conducted of adult patients with biochemically confirmed spontaneous cerebrospinal fluid leak. Demographics and radiological features identified on computed tomography imaging of the temporal bones and/or magnetic resonance imaging were analysed.

RESULTS

Sixty-one patients with spontaneous cerebrospinal fluid leak were identified. Fifty-four patients (88.5 per cent) underwent both temporal bone computed tomography and magnetic resonance imaging. Despite imaging revealing bilateral defects in over 75 per cent of the cohort, only two patients presented with bilateral spontaneous cerebrospinal fluid leaks. Anterior tegmen mastoideum defects were most common, with an average size of 2.5 mm (range, 1-10 mm).

CONCLUSION

Temporal bone computed tomography is sensitive for the identification of defects when suspicion exists. In the setting of an opacified middle ear and/or mastoid, close examination of the skull base is crucial given that this fluid is potentially cerebrospinal fluid.

A 3D-printed Lateral Skull Base Implant for Repair of Tegmen Defects: A Case Series

OBJECTIVE

To determine the feasibility of a patient-specific, three-dimensionally (3D)-printed reconstruction plate for repair of lateral skull base defects.

STUDY DESIGN

Prospective case series and cadaveric study.

SETTING

A university-based, tertiary care hospital.

PATIENTS

Three patients with lateral skull base defects and five cadavers.

MAIN OUTCOME MEASURE(S)

Caliper gauge fit testing was performed in the cadaver temporal bones to determine the fit of the tegmen plate in engaging the tegmen defect. Additionally, three patients underwent standard of care reconstruction of their middle fossa floor using autografts or allografts. Temporary plate insertion during standard operative repair was performed to gauge feasibility and fit. Operative time required for standard grafting compared with placement of the tegmen plate was examined.

RESULTS

Real-time, intraoperative placement of the tegmen plate in our patients under 1 minute compared with nearly 60 minutes for standard surgical repair. Tegmen plates covered the defects and locked into place from contour matching without impinging on critical structures. Fit testing revealed flush-fitting plates to the cadaveric temporal bone surface with all gaps less than 500 μm.

CONCLUSIONS

Computer modeling and 3D printing can design custom fitted tegmen reconstruction plates for temporal bone defects. Versatility in prefabrication and 3D modeling shows potential in allowing the construct to avoid critical structures and adequately cover defects with high precision to the tegmen surface.

Is Septal Cartilage Graft via Transmastoid Approach Safe Enough in the Repair of Large Tegmen Defects?

INTRODUCTION

Tegmen defect (TD) has a potential of intracranial spread of middle ear infection, meningoencephalic herniation (MEH), and cerebrospinal fluid leakage (CSFL). Especially the defects >1 cm with MEH or CSFL are generally repaired via the classical middle fossa or minicraniotomy technique. The aim of this study was to show the efficiency of the intracranial, extradural placement of the septal cartilage graft in the closure of the TD larger than 1 cm via the transmastoid (TM) approach.

METHODS

The demographic, preoperative, intraoperative, and postoperative data of 11 patients with chronic otitis media (COM) who had TD larger than 1 cm were reviewed retrospectively. Hospitalization time and hearing preservation with respect to MEH or CSFL were analyzed.

RESULTS

The most common etiology of TD was cholesteatoma (82%), and 91% of the patients had multiple COM surgery history. The mean TD size was 15.4 (10-25) mm. Fifty-five percent of the patients presented with either MEH or CSFL. The mean follow-up of the patients was 22.5 (8-42) months. There was no significant difference between preoperative and postoperative mean bone conduction thresholds. Mean hospitalization time was 5.2 (3-10) days. There was no significant difference in the hospitalization time between patients with MEH or CSFL and without MEH or CSFL. Neither recurrence nor graft infection was encountered.

CONCLUSION

Extradural grafting with the septal cartilage in the large TD up to 25 mm can be repaired efficiently via the TM approach without application of a lumbar drainage.

Prevalence and Outcome of Anterior and Middle Cranial Fossae Encephaloceles without Cerebrospinal Fluid Leak or Meningitis

BACKGROUND

With advances in imaging techniques, encephaloceles, meningoceles, and meningoencephaloceles are occasionally discovered incidentally. These can be located in anterior cranial fossa (ACF), mostly protruding into sphenoid and ethmoid sinuses, or middle cranial fossa (MCF), protruding into the temporal bone. We reviewed a large series of cranial computed tomography and magnetic resonance imaging scans to identify the prevalence of asymptomatic encephaloceles, meningoceles, and meningoencephaloceles and describe their outcome.

METHODS

We retrospectively reviewed a database of all magnetic resonance imaging and computed tomography scans done at Weill Cornell Medicine for any reason between 2003 and 2018. Encephaloceles, meningoceles, or meningoencephaloceles were confirmed on 72 scans. Of these, chart reviews were performed to identify incidentally discovered cases with symptoms other than cerebrospinal fluid leak, and chart reviews and phone calls were conducted to determine patient demographics, treatment, and outcome.

RESULTS

There were 18 incidental cases for a prevalence of 0.0074%, of which 6 were located in ACF, and 12 were located in MCF. The mean age for ACF cases was 39 ± 15.9 years and for MCF cases was 49.5 ± 19.8 years. There were no leaks in any cases after the encephaloceles were discovered. Eleven of 12 (91.6%) MCF cases were treated conservatively, while 3 of 6 (50%; P = 0.083) ACF cases were treated surgically.

CONCLUSIONS

This study showed that encephaloceles, meningoceles, and meningoencephaloceles without cerebrospinal fluid leak or meningitis in MCF were more often conservatively managed with observation only, whereas these entities in ACF were often repaired prophylactically. Incidentally discovered encephaloceles have a relatively benign natural history and do not precipitously leak.

[Exudative otitis media as a manifestation of spontaneous otoliquorrhea]

Spontaneous otoliquorrhea (SOL) often mimics the picture of exudative otitis media (EOM), which leads to delayed diagnosis of the underlying disease.

PURPOSE OF STUDY

Is to evaluate causes, clinical features and diagnostic algorithm for patients with SOL.

PATIENTS AND RESEARCH METHODS

From 2007 to 2018, 33 patients with SOL underwent examination and treatment in the Department of Ear Microsurgery of the Institute. At the preoperative stage, all patients underwent a complete examination, including examination of ENT organs, anthropometric, biochemical, audiological, ultrasound and radiological tests, which made it possible to make the correct diagnosis.

RESULTS

SOL was more likely to occur in women over 50 who are obese (69.7%, stage II-III). The disease onset in 51.6% of patients was preceded by conditions accompanied by a short-term or prolonged increase in intracranial pressure. SOL was manifested by the clinical picture of EOM in 72.7% of cases, only in 45.5% of cases was accompanied by release from the ear and nose, was often intermittent and complicated by meningitis in 12.1% of patients. Difficulties in diagnosing the disease are caused by clinical manifestations of exudative or acute otitis media in the absence of a causative factor, which led to the verification of SOL from 1 to 4 years in 81.9% of patients who received long-term treatment for other ENT diseases.

CONCLUSION

The master factors in the diagnosis of SOL are otomicroscopy and endoscopy of the nasopharynx, Halo test and screening determination of glucose level in the obtained discharge, as well as high-resolution CT of the temporal bone, which allows to localize the cerebrospinal fluid fistula and to determine the size of the defect.

Temporal Bone Encephaloceles: Utility of Preoperative Imaging

Objective

To determine the diagnostic efficacy and clinical value of preoperative computed tomography (CT) and magnetic resonance imaging (MRI) among patients with suspected temporal bone encephaloceles (TBE).

Study Design

Retrospective chart review from 2006 to 2018.

Setting

Tertiary referral center.

Subjects and Methods

The subjects underwent surgery for a clinically suspected TBE or cerebrospinal fluid (CSF) leak. Preoperative imaging test characteristics of CT and MRI, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were calculated for TBE scans and compared with intraoperative findings.

Results

Fifty-seven subjects with otorrhea, middle ear effusion, hearing loss, and/or meningitis with suspected TBE or CSF leak were identified. All had preoperative CT scans, and 61% (35/57) had preoperative MRI scans. Intraoperatively, 37 of 57 patients (65%) were found to have a TBE. CT scans (17% sensitivity, 100% specificity, 100% PPV, 46% NPV) were less sensitive than MRI (58% sensitivity, 100% specificity, 100% PPV, 24% NPV) for detecting TBEs. Furthermore, the time from initial scan to operative repair was significantly longer in those who had a CT followed by MRI scan compared with CT alone or a fused CT-MRI scan (mean = 68 vs 15 days, respectively; P = .004).

Conclusion

CT and MRI provide complementary information that may aid surgical planning. However, imaging cannot always rule out TBE. In cases with high clinical suspicion, surgical confirmation is often required for definitive diagnosis and treatment. The cost of an additional preoperative study should be considered before its use.

Spontaneous Idiopathic Cerebrospinal Fluid Rhinorrhea

Cerebrospinal fluid rhinorrhea is described as cerebrospinal fluid flow through the nose due to the abnormal connection of the subarachnoid space and sinonasal cavity. Spontaneous idiopathic rhinorrhea is a rarely seen disease. Besides the patient's clinical presentation detailed radiological evaluation and other invasive procedures must be carried out to confirm the diagnosis. Its treatment is compelling due to high recurrence rates. In the treatment algorithm when conservative treatment modalities had been proven inadequate, surgical repair must follow in order. In this paper the authors present the details of 2 cases of spontaneous rhinorrhoea patients.

Repair of encephalocele and cerebrospinal fluid leak with the use of bone morphogenetic protein: A case report

Background:

Encephaloceles are rare phenomena which occur when brain parenchyma herniates through a skull defect which, if left untreated, may lead to significant issues such as cerebrospinal fluid (CSF) fistulas, meningitis, and intractable seizures. Due to the rarity and variety in size and location of encephaloceles, no standard technique has been established for the resultant defect. Herein, we demonstrate the safe and effective use of bone morphogenetic protein (BMP) in the repair of CSF leak caused by encephalocele.

Case Description:

A retrospective chart review was conducted on a 50-year-old female who presented with sudden onset spontaneous right nostril CSF leak due to the right lateral sphenoid sinus recess encephalocele, for which she underwent surgical repair. After resecting the encephalocele, cadaver crushed bone was used to fill the skull base defect. Following, an absorbable sponge from the extra-small BMP kit was cut in half and soaked with recombinant human BMP-2 (rhBMP-2) before being laid over the bony defect. On postoperative clinic visits at 2 weeks and at 3 months, the patient demonstrated good recovery without evidence of recurrent CSF leak. On follow-up computed tomography imaging at 9 months’ postsurgery, there was no evidence of recurrent CSF leak or encephalocele, infection, ectopic bone formation, excessive inflammation, or neoplasm.

Conclusion:

In this case, we demonstrate the successful use of BMP for the repair of CSF leak due to encephalocele. It is our extrapolation that the pro-inflammatory properties of rhBMP-2 lead to the prevention of recurrent CSF leak.

Management of spontaneous temporal bone cerebrospinal fluid leak: A 30-year experience

PURPOSE

The goal of this study was to describe the incidence of and our long-term results in the management of spontaneous temporal bone CSF leak and to determine if there is any association with an increase in body mass index (BMI).

METHODS

This was an Institutional Review Board (IRB) approved retrospective review of 58 patients who underwent repair of spontaneous temporal bone CSF leaks by a single surgeon at a tertiary care academic medical center between 1988 and 2017. Patients with CSF leaks due to trauma, iatrogenic injury, or chronic infection were excluded. Surgical approaches included middle cranial fossa, transmastoid, or a combination of both. Cases were divided into three decades. Patient demographics, clinical features, audiologic results, imaging studies, operative findings, complications, and long-term results were reviewed with a specific emphasis on the potential correlation with BMI.

RESULTS

The average BMI was 32. There was a statistically significant increase in BMI between the two most recent decades (p = 0.044). The middle cranial fossa was the most commonly utilized approach. Multiple tegmen defects were often noted on imaging and intraoperatively.

CONCLUSION

There is an increase in the incidence of spontaneous CSF leaks possibly associated with an increase in BMI in the United States over the last 30 years.

Cerebrospinal Fluid Leakage During Temporal Bone Surgery: Selecting Intra-operative Dural Closure with a Dumbbell-Shaped Muscle Graft as a Surgical Approach

Cerebrospinal fluid (CSF) leakages of the temporal bone may arise during mastoid surgery. The leakages can have multiple potential etiologies, for instance, using a cutting burr near the bony tegmen or monopolar electrocautery on the surface of the dura mater. In this paper, we introduced an effective and simple technique for the management of CSF leakages of the temporal bone. In a prospective case series, 36 patients (16 males and 20 females) who have had an experience of incidental or inevitable CSF otorrhea or otorhinorrhea during temporal bone surgery were selected. All patients were treated using a muscle graft in a dumbbell-shaped design through the dura defect at the Amir-Alam University Hospital between April 2005 and November 2008. The mean size of the defects was 5 mm (a range of 2-10 mm). A dumbbell-shaped autologous muscle graft was immediately successful in sealing the leakage in all patients. Only five patients (13.8%) had some evidence of leakage remaining on the day after the operation, which was subsequently resolved by conservative management in four of them (11.1%). Only one patient (2.7%) was subjected to a second operation for a new defect. Recurrence of CSF leakage or other related complications were not observed during about 7 years of follow up. A free autologous muscle graft, using the dumbbell technique through a small to moderate dura defect is an effective, easily performed, and safe method to seal iatrogenic leakages of the temporal bone.

Middle cranial fossa approach to repair tegmen defects assisted by three-dimensionally printed temporal bone models

OBJECTIVES/HYPOTHESIS

To explore the perioperative utility of three-dimensionally (3D)-printed temporal bone models of patients undergoing repair of lateral skull base defects and spontaneous cerebrospinal fluid leaks with the middle cranial fossa approach.

STUDY DESIGN

Case series.

METHODS

3D-printed temporal bone models-based on patient-specific, high-resolution computed tomographic imaging-were constructed using inexpensive polymer materials. Preoperatively, the models demonstrated the extent of temporal lobe retraction necessary to visualize the proposed defects in the lateral skull base. Also preoperatively, Silastic sheeting was arranged across the modeled tegmen, marked, and cut to cover all of the proposed defect sites. The Silastic sheeting was then sterilized and subsequently served as a precise intraoperative template for a synthetic dural replacement graft. Of note, these grafts were customized without needing to retract the temporal lobe.

RESULTS

Five patients underwent the middle cranial fossa approach assisted by 3D-printed temporal bone models to repair tegmen defects and spontaneous cerebrospinal fluid leaks. No complications were encountered. The prefabricated dural repair grafts were easily placed and fit precisely onto the middle fossa floor without any additional modifications. All defects were covered as predicted by the 3D temporal bone models. At their postoperative visits, all five patients maintained resolution of their spontaneous cerebrospinal fluid leaks.

CONCLUSIONS

Inexpensive 3D-printed temporal bone models of tegmen defects can serve as beneficial adjuncts during lateral skull base repair. The models provide a panoramic preoperative view of all tegmen defects and allow for custom templating of dural grafts without temporal lobe retraction.

LEVEL OF EVIDENCE

4 Laryngoscope, 127:2347-2351, 2017.