The Effectiveness and Safety of Intrathecal Fluorescein in the Management of Cerebrospinal Fluid Leaks

Abstract

Background Cerebrospinal fluid (CSF) leaks can be associated with significant morbidity such as meningitis. Surgical management has proven effective, with endoscopic approaches having become the gold standard due to success rates >90%. Inability to localise the leak site prior to surgery is associated with surgical failure. The use of intrathecal fluorescein (IF) to localise CSF fistulae sites was first demonstrated in 1960. Despite this, its use in this context is unlicensed. Objective Evaluate the safety and efficacy of IF use in the management of CSF leak repairs in our centre. Methods All patients who underwent endoscopic repair of CSF fistula by a single surgeon where IF was used between January 2010 – September 2019 at a single-centre (tertiary skull base referral unit in the United Kingdom) were retrospectively analysed. Primary outcome measures were localisation of CSF fistula with IF (efficacy) and peri-operative complications likely to be attributable to IF (safety). Results There were 55 patients included (60 procedures) with a positive localisation rate of 90.0% with IF. The overall peri-operative complication rate was 8.3% (n = 5). It is likely that none were related to IF use. However, three complications may be linked giving a complication rate potentially related to IF of 5.0%. There were no peri-operative mortalities. Conclusion Many studies have demonstrated IF to be safe at low doses (<50mg) with a high sensitivity, specificity and positive predicative value. Our results demonstrate that the use of IF in our centre is safe and effective at identifying CSF fistulae. While we have reported some complications in our cohort, these were unlikely to be directly attributable IF use. We have described no serious complications such as seizures, limb weakness or death. We believe this study adds to the growing body of evidence that IF use in the management CSF fistula repairs is safe and effective.

Systematic Review: Evaluating the Efficacy of Intrathecal Fluorescein for Localizing Cerebrospinal Fluid Rhinorrhea

“…Only 1 study 27 reported comorbidities of all patients who had IF injections in their cohort; 82% of these patients were obese. The average first-time repair success rate in the 9 studies 1,8,10,11,17,20,22,24,28 that reported data was 94.9 ± 4.4% (83.0%-98.3%). One study 26 reported the average duration of surgery was 196 minutes (70-405 minutes).…”

“…3,4 The efficacy of endoscopic approaches for repairing skull base defects causing CSF rhinorrhea primarily depends on successful identification of the source of a CSF leak. 1,5 Computed tomography and magnetic resonance imaging are routinely used for leak localization; 3,6 however, the translucent appearance of CSF and the presence of blood or secretions can make it difficult to recognize small, low-flow CSF leaks on imaging, especially if a leak is suspected within an existing surgical site. 7 Consequently, intrathecal administration of fluorescein (IF) is often used to localize the site of leakage.…”

“…Common causes of CSF rhinorrhea include trauma, tumors, and benign intracranial hypertension. 1 Successful surgical closure of CSF leaks is essential in preventing intracranial complications, including meningitis, pneumocephalus, and brain herniation. 2 Endoscopic surgery is the current gold standard for repair of skull base defects leading to CSF rhinorrhea, with success rates > 90% reported in the literature.…”

To Think Outside the Box Requires Stepping Outside of Your Comfort Zone

“…18 Such training modules will likely become standard practice in a similar way that temporal bone lab curricula have in otolaryngology training and cadaveric dissection curricula have started to become adopted in neurosurgery training. 19 Finally, from a visualization standpoint, we are reminded by Jolly and colleagues of the benefit that intrathecal fluorescein can offer in identifying cerebrospinal fluid leak (CSF) sites at the skull base 20 Despite the wealth of technical descriptions and approaches, fresh ideas continue to arise on how to access complicated regions to accomplish preset goals while minimizing morbidity. Huang, Low, and Stokken discuss an anterior inferior approach to endoscopic medial maxillectomy for maxillary sinus lesions that is now possible given current knowledge of anatomy, instrumentation, and imaging and navigation technology.…”

“…18 Such training modules will likely become standard practice in a similar way that temporal bone lab curricula have in otolaryngology training and cadaveric dissection curricula have started to become adopted in neurosurgery training. 19 Finally, from a visualization standpoint, we are reminded by Jolly and colleagues of the benefit that intrathecal fluorescein can offer in identifying cerebrospinal fluid leak (CSF) sites at the skull base 20…”