Spontaneous cerebrospinal fluid leaks in the anterior skull base: a surgical challenge

Spontaneous cerebrospinal fluid rhinorrhea as a primary presentation of idiopathic intracranial hypertension, management strategies, and clinical outcome

Background

Causes of cerebrospinal fluid (CSF) rhinorrhea could be divided into primary (spontaneous) and secondary (head trauma and iatrogenic). Idiopathic intracranial hypertension (IIH) has emerged as a cause for spontaneous CSF rhinorrhea but is still underestimated, may be overlooked and needs special consideration in management. The objective of this study is to demonstrate spontaneous CSF rhinorrhea as the primary presentation of IIH and explore the algorithm of management.

Methods

All patients with spontaneous (primary) CSF rhinorrhea were included with complete clinical and radiological assessment. We performed lumbar puncture and CSF pressure measurements in the lateral decubitus position for all included patients to detect those with intracranial hypertension. A pressure of 20 cmH2O in cases of CSF rhinorrhea is considered a cutoff for diagnosing raised intracranial pressure. When intracranial hypertension was diagnosed, patients were subjected immediately to lumboperitoneal shunt. If CSF leakage stopped after shunt insertion, we would not perform skull base repair, and the patient was sent for follow-up. However, if CSF leakage did not stop after shunt insertion despite normalization of intracranial tension or recurrence of CSF rhinorrhea despite shunt patency or there was intracranial pneumocephalus, skull base repair would be performed.

Results

During the period of the study, 293 cases of CSF rhinorrhea were seen. Only 42 (14.3%) patients were diagnosed with spontaneous CSF rhinorrhea, and the remaining were posttraumatic. Thirty-seven patients (88.1%) of 42 patients revealed high CSF pressure readings. All 37 patients received lumboperitoneal shunt followed by CSF rhinorrhea stoppage. Later, during follow-up, 7 patients developed recurrence of leakage; 3 of them revealed shunt obstruction, and rhinorrhea improved after shunt revision. The other 4 patients revealed patent shunt and needed skull base repair.

Conclusion

Spontaneous CSF rhinorrhea is considered secondary to IIH until proven otherwise. Initial placement of lumboperitoneal shunt may provide an effective alternative to skull base repair for the treatment of patients with IIH presenting with CSF rhinorrhea.

Efficacy of Acetazolamide for Treatment of Iatrogenic, Traumatic, and Spontaneous Cerebrospinal Fluid Leaks of the Anterior Skull Base: A Systematic Review

A cerebral spinal fluid (CSF) leak from the anterior skull base is a challenging neurosurgical issue that requires prompt recognition and treatment. Options for treatment include medical and surgical repair. A systematic review was performed screening for both retrospective and prospective clinical studies evaluating the efficacy of acetazolamide in the event of CSF leaks of the anterior skull base.  We initially screened a total of 149 studies for inclusion, and 25 of them met the inclusion criteria. We included four studies on iatrogenic CSF leaks caused by surgery of the anterior cranial fossa, three studies on traumatic CSF leaks, and 18 studies on spontaneous CSF leaks caused by idiopathic intracranial hypertension (IIH). In the event of an iatrogenic CSF leak, 68 patients had undergone an endoscopic endonasal approach. CSF diversion and high-volume lumbar puncture were used frequently with adjunct acetazolamide administration. In the event of trauma, 187 patients were evaluated across the three included studies. Acetazolamide treatment was used as a single approach and effectively controlled CSF leaks. For spontaneous CSF leaks, acetazolamide is frequently used to increase the efficacy of surgical repair. Of the 431 patients, 327 received temporary CSF diversion in addition to acetazolamide. Surgical repair was the primary treatment in 277 patients. Acetazolamide should be considered as a treatment option in patients with CSF leak secondary to surgery of the anterior cranial fossa, trauma, and idiopathic causes.

Endoscopic Transpterygoid Repair of Sphenoid Sinus Meningocele: A Comprehensive Case Report and Literature Review

We report a challenging and uncommon case involving a 53-year-old Japanese man with cerebrospinal fluid (CSF) leakage caused by a meningocele in the lateral recess of the sphenoid sinus. Our innovative treatment approach involved a combination of transpterygoid and endoscopic modified medial maxillectomy techniques, with special emphasis on the preservation of the sphenopalatine artery. This strategic preservation was pivotal to the successful use of the ipsilateral nasoseptal flap for reconstruction, which played a crucial role in the prevention of postoperative CSF leakage. Otolaryngologists and neurosurgeons collaborated to perform the bath-plugging technique; effective collaboration was instrumental to the success of the procedure. This report highlights significant advancement from conventional frontal craniotomy to a more sophisticated endoscopic technique, shows the importance of meticulous surgical planning and execution, emphasizes careful preservation of critical anatomical structures during complex neurosurgical and otolaryngological procedures, and underscores the evolving landscape of surgical approaches for managing complex medical conditions.

Lateral Transorbital Versus Endonasal Transpterygoid Approach to the Lateral Recess of the Sphenoid Sinus-A Comparative Anatomic Study

BACKGROUND

The treatment of cerebrospinal fluid leaks of the lateral recess of the sphenoid sinus (LRSS) faces difficulties due to the deep location of the osseous defect. When treated with craniotomies, brain retraction is a concern. The endoscopic endonasal transpterygoid approach (EETA) is a direct and less invasive procedure; however, it may require transection of the vidian nerve (VN).

OBJECTIVE

To investigate the feasibility of a lateral transorbital approach (LTOA) as an alternative pathway to the LRSS that avoids VN sacrifice.

METHODS

Six embalmed heads with well-pneumatized LRSS were preselected by inspecting their computed tomography scans. One LTOA and one EETA were performed on 1 side of each specimen. The approaches were compared regarding working distance and neurovascular structures being sacrificed. The working area of the LTOA was also measured.

RESULTS

The average working distances were 59.9 (±2.94) mm for the LTOA and 76.4 (±3.99) mm for the EETA (P < .001). The LTOA generated a working area with a diameter of 9 to 14 mm. The EETA demanded the sacrifice of VN and the sphenopalatine artery in all specimens to expose the LRSS. No neurovascular structures were found in the trajectory of the LTOA.

CONCLUSION

The LTOA to the LRSS is feasible, with minimal risk of injuring neurovascular structures. It offers a shorter pathway when compared to the EETA. Although the LTOA provides no options for vascularized flap reconstruction, it allows immediate access to muscle grafts. The LTOA may serve as an alternative to treating cerebrospinal fluid leaks of the LRSS.

Do Most Patients With a Spontaneous Cerebrospinal Fluid Leak Have Idiopathic Intracranial Hypertension?

BACKGROUND

The association between cerebrospinal fluid (CSF) leaks at the skull base and raised intracranial pressure (ICP) has been reported since the 1960s. It has been suggested that spontaneous CSF leaks might represent a variant of idiopathic intracranial hypertension (IIH). We review the evidence regarding the association between spontaneous CSF leaks and IIH, and the role of ICP in the pathophysiology of nontraumatic skull base defects. We also discuss the management of ICP in the setting of CSF leaks and IIH.

EVIDENCE ACQUISITION

References were identified by searches of PubMed from 1955 to September 2018 with the terms "idiopathic intracranial hypertension" and "cerebrospinal fluid leak." Additional references were identified using the terms "pseudotumor cerebri," "intracranial hypertension," "benign intracranial hypertension," and by hand search of relevant articles.

RESULTS

A CSF leak entails the egress of CSF from the subarachnoid spaces of the skull base into the surrounding cavitary structures. Striking overlaps exist regarding demographic, clinical, and radiological characteristics between IIH patients and those with spontaneous CSF leaks, suggesting that some (if not most) of these patients have IIH. However, determining whether a patient with spontaneous CSF leak may have IIH may be difficult, as signs and symptoms of raised ICP may be obviated by the leak. The pathophysiology is unknown but might stem from progressive erosion of the thin bone of the skull base by persistent pulsatile high CSF pressure. Currently, there is no consensus regarding the management of ICP after spontaneous CSF leak repair when IIH is suspected.

CONCLUSIONS

IIH is becoming more widely recognized as a cause of spontaneous CSF leaks, but the causal relationship remains poorly characterized. Systematic evaluation and follow-up of patients with spontaneous CSF leaks by neuro-ophthalmologists will help clarify the relation between IIH and spontaneous CSF leaks.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Successful Treatment of Spontaneous Cerebrospinal Fluid Rhinorrhea With Endoscopic Third Ventriculostomy and Lumboperitoneal Shunt: A Case Report

Spontaneous cerebrospinal fluid (CSF) rhinorrhea represents an important clinical entity that is being observed with increasing prevalence, ranging from 14 to 55%. Spontaneous CSF rhinorrhea is associated with elevated intracranial pressure (ICP), which is rarely stopped without surgical intervention. Endoscopic endonasal repair is typically warranted for CSF rhinorrhea. However, the recurrence rate of CSF leaks after the endoscopic endonasal repair of skull base defects due to ICP is usually high. We describe a 25-year-old man without a history of head injury, tumor, or obesity. The onset of his symptoms occurred in 1 week in the form of a persistent clear left nostril rhinorrhea. Computed tomography (CT) and magnetic resonance images (MRI) showed signs of CSF in the left sphenoidal sinus, meningocele in the left frontal sinus, empty sella, hydrocephalus, and Chiari I malformation (CIM). Cine-MRI revealed the flow of CSF was obstructed at the aqueduct and the outlet of the fourth ventricle. Endoscopic third ventriculostomy (ETV) was performed for the patient with obstructive hydrocephalus. Post-operative CSF pressure measurement demonstrated elevated ICP. The patient still had case of CSF rhinorrhea, and subsequently underwent lumboperitoneal shunt (LPS) for treatment of ICP. The patient showed a prompt resolution of CSF leak. Ten months later, the patient showed a significant improvement in terms of his herniated tonsil and cessation of CSF rhinorrhea.

Endoscopic Endonasal Transpterygoid Approach to Sphenoid Sinus Lateral Recess Defects

Background  Lesions affecting sphenoid sinus lateral recess (SSLR) are difficult to visualize and manipulate through the transnasal routes, especially when the sinus is highly pneumatized. External approaches to this area involve extensive surgery and are associated with significant morbidity. The aims of this study are to present our experience with the endoscopic transpterygoid approach as a method for approaching lesions of the SSLR and to evaluate the outcomes of this procedure. Methods  Clinical charts of patients who had lesions in the SSLR and who were treated at our institution from September 1998 to June 2018 were retrospectively reviewed. All these patients were managed by the endoscopic endonasal transpterygoid approach. Results  Thirty-nine patients were identified. No cerebrospinal fluid leak recurrences were observed during follow-up (range: 1-19.7 years; median: 2.3 years). Hypoesthesia (temporary, 1; persistent, 4) in the region innervated by the maxillary branch of the trigeminal nerve was detected in five (12.8%) patients, while symptoms due to the Vidian nerve damage (dry eye, 3; dry nasal mucosa, 1) were present in four (10%) patients. Conclusions  Although the endoscopic endonasal transpterygoid approach is an excellent corridor for dealing with lesions of the SSLR, limited rate of neurologic and lacrimal complications was observed. Potential morbidity of the intervention should be discussed during preoperative counselling.

A Systematic Review of Secondary Cerebrospinal Fluid Leaks

Background

Secondary cerebrospinal leaks (CSF) are leaks that recur after an initial endoscopic repair of CSF leaks. Identification of characteristics that could predict secondary leaks may allow surgeons to plan repairs with the knowledge that these defects are more likely to fail.

Objective

To identify characteristics that could predict secondary CSF leaks.

Methods

A search of all studies that reported outcomes after endoscopic repair of CSF leaks was conducted by using medical literature data bases. Studies with the following criteria were included: written in the English language, secondary CSF leaks after primary repair, and assessment of success of fistula repair. Data extracted included the etiology of the leak, site of the leak, reconstructive materials used, and success of the repair.

Results

Ninety-four studies, from 1988 to 2015, with a total of 3149 primary CSF leaks were included. Sixty-three studies (67%) had a success rate of ≥80%; 77 studies (82%) had secondary leak rates of <40%. For 88 of the 94 studies (94%), the success rate after secondary repair improved to 81.0–100%. Of 48 studies that included leaks of more than one site, the sphenoid was the most common site of leak in 26 studies (55%), the ethmoid was the most common site in 16 studies (34%), and the cribriform was the most common site in 11 studies (23%).

Conclusion

The rate of secondary CSF leaks was low due to advances in endoscopic repair techniques. Spontaneous and iatrogenic CSF leaks were more likely to recur, especially without adequate control of underlying factors, such as increased intracranial pressure and obesity. Further studies with consistent reporting are required for more definitive conclusions about secondary CSF leaks.

Surgical repair of spontaneous cerebrospinal fluid (CSF) leaks: A systematic review

Objectives

To review the safety and efficacy of surgical management for spontaneous cerebrospinal fluid (CSF) leaks of the anterior and lateral skull base.

Data Sources

A systematic review of English articles using MEDLINE.

Review Methods

Search terms included spontaneous, CSF, cerebrospinal fluid, endoscopic, middle fossa, transmastoid, leak, rhinorrhea. Independent extraction of articles by 3 authors.

Results

Patients with spontaneous CSF leaks are often obese (average BMI of 38 kg/m²) and female (72%). Many patients also have obstructive sleep apnea (∼45%) and many have elevated intracranial pressure when measured by lumbar puncture. In addition to thinning of the skull base, radiographic studies also demonstrate cortical bone thinning. Endoscopic surgical repair of anterior skull base leaks and middle cranial fossa (MCF) approach for repair of lateral skull base leaks are safe and effective with an average short‐term failure rate of 9% and 6.5%, respectively. Long‐term failure rates are low. One randomized trial failed to show improved success of anterior leak repairs with the use of a lumbar drain (LD) (95% with vs. 92% without; P = 0.2). In a large retrospective cohort of MCF lateral skull base repairs, perioperative LD use was not necessary in >94% of patients.

Conclusions

Spontaneous CSF leaks are associated with female gender, obesity, increased intracranial hypertension, and obstructive sleep apnea. Endoscopic repair of anterior skull base leaks and MCF or transmastoid approaches for lateral skull base leaks have a high success rate of repair. In most cases, intraoperative placement of lumbar drain did not appear to result in improved success rates for either anterior or lateral skull base leaks.

Level of Evidence

2a, Systematic Review.

Spontaneous cerebrospinal fluid leaks in the anterior skull base secondary to idiopathic intracranial hypertension

Spontaneous cerebrospinal fluid (CSF) leaks represent a clinical entity in which CSF rhinorrhea occurs in the absence of any inciting event. Spontaneous CSF leaks are associated with elevated intracranial pressure (ICP) or have underlying idiopathic intracranial hypertension (IIH). We report a cohort of patients who have undergone nasal endoscopic repair for spontaneous CSF leaks. We review our perioperative complications and the effectiveness of the nasal endoscopic approach to repair spontaneous CSF leaks. Also, we examine the evidence correlating spontaneous CSF leaks and IIH and the role of decreasing ICP in the treatment of nasal spontaneous CSF leaks. A retrospective analysis of patients with nasal spontaneous cerebrospinal fluid leaks was performed. Data on the nature of presentation, patient body mass index, defect location and size, ICP, clinical follow-up, and complications were collected. Thirty-five patients had nasal spontaneous cerebrospinal fluid leaks with evidence of IIH's symptoms. The most common sites were the cribriform plate, the ethmoid roof, and sphenoid lateral pterygoid recess. All patients underwent endonasal endoscopic surgery to repair the defect. Postoperatively, all patients underwent lumbar drainage and acetazolamide therapy. Nasal spontaneous cerebrospinal fluid leaks represent a surgical challenge because of their high recurrence rates. The most important factor for obtaining a successful repair in these patients is reducing their intracranial pressure through nutritional, medical, or surgical means.

Efficacy of Perioperative Lumbar Drainage following Endonasal Endoscopic Cerebrospinal Fluid Leak Repair: A Meta-analysis

Objective

Perioperative lumbar drain (LD) use in the setting of endoscopic cerebrospinal fluid (CSF) leak repair is a well-established practice. However, recent data suggest that LDs may not provide significant benefit and may thus confer unnecessary risk. To examine this, we conducted a meta-analysis to investigate the effect of LDs on postoperative CSF leak recurrence following endoscopic repair of CSF rhinorrhea.

Data Sources

A comprehensive search was performed with the following databases: Ovid MEDLINE (1947 to November 2015), EMBASE (1974 to November 2015), Cochrane Review, and PubMed (1990 to November 2015).

Review Method

A meta-analysis was performed according to PRISMA guidelines.

Results

A total of 1314 nonduplicate studies were identified in our search. Twelve articles comprising 508 cases met inclusion criteria. Overall, use of LDs was not associated with significantly lower postoperative CSF leak recurrence rates following endoscopic repair of CSF rhinorrhea (odds ratio: 0.89, 95% confidence interval: 0.40-1.95) as compared with cases performed without LDs. Subgroup analysis of only CSF leaks associated with anterior skull base resections (6 studies, 153 cases) also demonstrated that lumbar drainage did not significantly affect rates of successful repair (odds ratio: 2.67, 95% confidence interval: 0.64-11.10).

Conclusions

There is insufficient evidence to support that adjunctive lumbar drainage significantly reduces postoperative CSF leak recurrence in patients undergoing endoscopic CSF leak repair. Subgroup analysis examining only those patients whose CSF leaks were associated with anterior skull base resections demonstrated similar results. More level 1 and 2 studies are needed to further investigate the efficacy of LDs, particularly in the setting of patients at high risk for CSF leak recurrence.