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

Abstract

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.

Keywords: CSF leak; Cerebrospinal fluid leak; MCF repair; anterior skull base; endoscopic repair; lateral skull base; obstructive sleep apnea; review; spontaneous.

Figure 1

Representative images from a patient with an anterior sCSF leak. (A) Coronal CT showing a defect in the right cribriform plate (arrow). (B) Coronal T2 MRI showing the resulting meningocele through the right cribriform plate into the nasal cavity.

Figure 2

Representative images from a patient with a lateral sCSF leak. (A) Representative coronal CT showing left tegmen mastoideum defect (arrow) with fluid in the middle ear and mastoid. (B) Axial CT demonstrating cortical skull thinning (arrowheads). (C) Intraoperative images showing tegmen defect with encephalocele (arrowhead) and dural defect (dotted line). L = Lateral, M = Medial, P = posterior, A = Anterior.

Figure 3

Search methodology for anterior and lateral skull base sCSF leak repairs.

Figure 4

Proposed etiology of sCSF Leaks. Obesity is associated with IIH and OSA. Both of these lead to constant or intermittent elevations of intracranial pressure which is believed to lead to calvarial and skull base thinning over time leading to spontaneous CSF leaks.