Management of recurrent cerebrospinal fluid leak, current practices and open challenges. A systematic literature review

Cerebrospinal fluid leak (CSFL) is a rare pathological condition which requires prompt and adequate management due to the high rate of associated major complications. At present, CSFL can be successfully treated through endoscopic endonasal approaches with success rates higher than 90%. Despite this, CSFL recurrence may occur, and its management is critical and still represents a matter of debate. A systematic review of the literature on the management of recurrent CSFL was conducted. It included a cohort of 1,083 cases of CSFL treated with surgical or conservative approaches; 112 cases of recurrence were reported for an overall recurrence rate of 10.3%. Most of the leaks were localised in the anterior skull base (68.3%) and identification of recurrent CSFL may be troublesome. Therefore, the entire skull base must be meticulously examined and long-term follow-up is mandatory. The risk for CSFL recurrence is higher in patients affected by idiopathic intracranial hypertension (IIH), but its role in CSFL recurrence is yet to be understood. Recurrent CSFL must be repaired as soon as possible in order to reduce the risk of intracranial complications. The use of early post-operative CSF diversion by lumbar drain (LD) is currently a matter of debate even in case of CSFL recurrences.

Postoperative protocols following endoscopic skull base surgery: An evidence-based review with recommendations

BACKGROUND

Postoperative management strategies for endoscopic skull base surgery (ESBS) vary widely because of limited evidence-based guidance.

METHODS

The PubMed, EMBASE, and Cochrane databases were systematically reviewed from January 1990 through February 2022 to examine 18 postoperative considerations for ESBS. Nonhuman studies, articles written in a language other than English, and case reports were excluded. Studies were assessed for levels of evidence, and each topic's aggregate grade of evidence was evaluated.

RESULTS

A total of 74 studies reporting on 18 postoperative practices were reviewed. Postoperative pain management, prophylactic antibiotics, and lumbar drain use had the highest grades of evidence (B). The literature currently lacks high quality evidence for a majority of the reviewed ESBS precautions. There were no relevant studies to address postoperative urinary catheter use and medical intracranial pressure reduction.

CONCLUSION

The evidence for postoperative ESBS precautions is heterogeneous, scarce, and generally of low quality. Although this review identified the best evidence available in the literature, it suggests the urgent need for more robust evidence. Therefore, additional high-quality studies are needed in order to devise optimal postoperative ESBS protocols.

Ventriculoperitoneal Shunt Alone for Cerebrospinal Fluid Rhinorrhea With Neuroendocrine Alterations in Idiopathic Intracranial Hypertension: A Case Report and Literature Review

Spontaneous skull base cerebrospinal fluid (CSF) leaks due to idiopathic intracranial hypertension (IIH) are a rare entity. Patients often present with CSF rhinorrhea, recurrent meningitis, chronic headache, and visual defects, while few patients have been reported to present with neuroendocrine alterations. Endonasal endoscopic repair is the first-line treatment for these leaks at present. However, the relatively high risk of recurrence remains the main cause of reoperation because of elevated intracranial pressure (ICP) after endoscopic surgery and absence of postoperative ICP management. A shunting procedure may stop CSF leakage or relieve symptoms in complex cases, and this is presently well-known as the last-line therapy for CSF liquorrhea. We describe a 29-year-old woman with spontaneous CSF rhinorrhea and neuroendocrine alterations due to IIH, and with no previous history of trauma, tumor, or nasal surgery. The bone defect in the skull base became implicated when the site of the leak was detected by cranial magnetic resonance imaging and computed tomography (CT). The patient was successfully managed via ventriculoperitoneal shunt (VPS) alone without endoscopic repair, and neuroendocrine alterations resolved after the shunting procedure.

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.

A Unique Subset: Idiopathic Intracranial Hypertension Presenting as Spontaneous CSF Leak of the Anterior Skull Base

Introduction Spontaneous cerebrospinal fluid (CSF) leaks represent a unique clinical presentation of idiopathic intracranial hypertension (IIH), lacking classical features of IIH, including severe headaches, papilledema, and markedly elevated opening pressures.

Methods Following a single-institution retrospective review of patients undergoing spontaneous CSF leak repair, we performed a literature review of spontaneous CSF leak in patients previously undiagnosed with IIH, querying PubMed.

Results Our literature review yielded 26 studies, comprising 716 patients. Average age was 51 years with 80.8% female predominance, and average body mass index was 35.5. Presenting symptoms included headaches (32.5%), visual disturbances (4.2%), and a history of meningitis (15.3%). Papilledema occurred in 14.1%. An empty sella was present in 77.7%. Slit ventricles and venous sinus stenosis comprised 7.7 and 31.8%, respectively. CSF leak most commonly originated from the sphenoid sinus (41.1%), cribriform plate (25.4%), and ethmoid skull base (20.4%). Preoperative opening pressures were normal at 22.4 cm H2O and elevated postoperatively to 30.8 cm H2O. 19.1% of patients underwent shunt placement. CSF leak recurred after repair in 10.5% of patients, 78.6% involving the initial site. A total of 85.7% of these patients were managed with repeat surgical intervention, and 23.2% underwent a shunting procedure.

Conclusion Spontaneous CSF leaks represent a distinct variant of IIH, distinguished by decreased prevalence of headaches, lack of visual deficits, and normal opening pressures. Delayed measurement of opening pressure after leak repair may be helpful to diagnose IIH. Permanent CSF diversion may be indicated in patients exhibiting significantly elevated opening pressures postoperatively, refractory symptoms of IIH, or recurrent CSF leak.

Management of anterior fossa cephaloceles

Skull base cephaloceles (SBCs) are defined as herniation of intracranial content through the skull base and are classified based on composition, etiology, and topographic location. Anterior SBCs frequently protrude in the sinonasal cavity, and consequently are at potential risk of infection. Therefore, the current recommendation is to treat SBCs with the primary intent of preventing meningitis, and surgery represents the mainstay of treatment. Anterior SBCs may display a wide spectrum of severity and complexity, and in each case the risks and benefits of surgical approaches are to be carefully weighted based on thorough assessment of symptoms, age, general conditions, location and size of the lesion, as well as expertise of the surgeon. In the last 30 years, the evolution and diffusion of transnasal endoscopic surgery have substantially changed the surgical management of the majority of SBC. In the past, they were treated exclusively with open transcranial approaches that may be burdened by relevant morbidity and risk for severe complications. The transnasal endoscopic corridor now provides easy access to the lesion and different reconstructive strategies using endonasal pedicled flaps, without any external incision, cranioplasty or brain manipulation. However, there are still scenarios in which an exclusive transnasal endoscopic route is contraindicated. The aim of the present review was to provide an overview on the comprehensive management of anterior SBC, with a particular focus on lesions suitable for endoscopic surgery. Furthermore, special aspects of SBC management in children and adults will be highlighted.

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.

Spontaneous CSF Leaks and IIH: A Flawless Connection? An Experience With 167 Patients

OBJECTIVES

Spontaneous cerebrospinal fluid (CSF) leaks are a rare but insidious clinical entity. In the recent literature, their pathogenesis has been linked with idiopathic intracranial hypertension (IIH). Considering a worse surgical outcome compared to traumatic leaks, a medical treatment of the underlying IIH has been suggested in order to prevent relapses. Nevertheless, some aspects of this rare pathology remain unclear. We report our long experience in the management of spontaneous CSF leaks.

METHODS

A retrospective evaluation of all patients with spontaneous CSF leaks treated from 1998 to 2018 in a tertiary referral center was carried out. All patients received surgery without any adjuvant routine medical treatment. Epidemiological and clinical data were reviewed. A telephone survey was conducted to investigate IIH-related symptoms in this population.

RESULTS

One hundred sixty-seven patients and 195 procedures were included in the study. The total rate of failure after surgical treatment was 9%. Eight patients suffered a relapse in the same site (4%, 8 of 195), whereas seven patients experienced a relapse in a different site (4%, 7 of 167). Twenty-nine percent of the population interviewed referred at least one IIH-related symptom.

CONCLUSION

Spontaneous CSF leaks represent a complex pathology that need a multidisciplinary evaluation. Surgical treatment seems to guarantee favorable results in most of the patients. Despite this, a not negligible percentage of patients experienced a relapse during a long-term follow-up. Further studies are needed to reach a deeper understanding of the presentation and course of this particular condition.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E401-E407, 2021.

Chemotherapy associated dural sinus thrombosis presenting as a cerebrospinal fluid leak

Despite the well documented increased risk of thrombosis in patients with cancer and during chemotherapy, cerebral venous sinus thrombosis (CVT) remains a rare entity. We present a rare case of cerebrospinal fluid (CSF) rhinorrhoea secondary to a left transverse sinus thrombus which occurred 2 years previously during chemotherapy for breast cancer. The patient underwent a three-layer repair using Neuro-Patch, septal cartilage and middle turbinate pedicle flap and was started on acetazolamide. There was no recurrence at 1-year follow-up. Raised intracranial pressure secondary to cerebral venous occlusion can erode the base of skull and predispose to CSF leaks. Despite the theoretical risk, there have been no cases reported where CSF leaks have occurred following chemotherapy induced CVT. We describe the first case and discuss pathophysiology and management.

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.

The use of polydioxanone plates for endoscopic skull base repair

BACKGROUND

Many reconstructive techniques and materials have been reported for repair of skull base defects after sinonasal tumor excision, cerebrospinal fluid (CSF) leaks, and coverage of denuded bone. Synthetic materials have been developed for endoscopic skull base repair to avoid donor-site morbidity. Polydioxanone plate is a bioabsorbable implant designed for nasal septal reconstruction and has the ability to retain strength for at least 10 weeks and absorbs in 6 months.

OBJECTIVES

This study aimed to describe the use of polydioxanone plates in endoscopic skull base defect and CSF leak repair, and to describe our experience with the surgical technique and postoperative management.

METHODS

This was a retrospective case series of patients who, between May 2013 and December 2015, underwent endoscopic sinus surgery and skull base repair for CSF leak or after excision of a skull base tumor by using polydioxanone plates. Patients who presented with sinonasal inflammatory disease or skull base tumors underwent endoscopic skull base repair by using polydioxanone plates in an underlay fashion and mucosal membrane grafts with or without adjuvant materials in an overlay fashion. The patients were reviewed at 6 days, 6 weeks, and 3 months after surgery. Postoperative adverse events, including CSF leak, infection, bleeding, headache, and graft failure, were recorded.

RESULTS

The cases of seven patients (five women, two men; mean age, 53.9 years) were reviewed. Five patients underwent sinonasal tumor resection and two underwent repair for CSF leak. The mean (standard deviation) defect size was 16.4 ± 11.4 mm. There was no evidence of postoperative CSF leak, and lumbar drains were not used. One patient reported transient headache and facial pressure at the 6-week follow-up visit. The surgeons' experience with polydioxanone plate placement, postoperative healing, and follow-up was satisfactory.

CONCLUSION

Polydioxanone could be used to achieve rigid repair of endoscopic skull base defects. These early results, although promising, require validation in clinical trials.

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.