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Oakley et al.

repairs withstood pressures ranging from 3.9 to 14.9 psi before failing (274 to 1048 cm H 2 O). 79, 81 Similarly, an in vitro study was performed using porcine fascia lata for repair, which also withstood pressures up to 6 times higher than normal intracranial pressure. 80 Human clinical studies are needed to determine if and how long restricted activity is necessary postoperatively. Aggregate grade of evidence: No evidence and therefore no specific recommendation can be made. Air travel Medical clearance for commercial air travel postoperatively is a common request from patients, but the appropriate tim ing for this has not yet been defined. There are case reports in the literature of patients developing pneumocephalus or bacterial meningitis after air travel who had recently under gone neurotologic surgery or were found to have skull-base bony defects, but no further studies. 83–85 Research is needed in this area to clarify when surgical patients can safely tol erate the atmospheric changes associated with air travel. Aggregate grade of evidence: No evidence and therefore no specific recommendation can be made. Medications In order to minimize risk to the endoscopic skull-base re pair from sudden increases in intracranial pressure, some surgeons prescribe patients medications such as antiemet ics, stool softeners, and antitussives. The efficacy and ne cessity of these postoperative medications is not known. A literature search identified 1 randomized, double-blind, placebo-controlled study that showed the utility of on dansetron in preventing postoperative vomiting in pediatric craniofacial surgery patients, a patient population also at risk of CSF leak. 86 However, there were no studies identi fied in active CSF leak patients, indicating a need for further research in this area. Aggregate grade of evidence: No evidence and therefore no specific recommendation can be made. Discussion Evidence-based medicine and practice relies on a critical and thoughtful review of the literature. Herein, we present a rigorous review of the current literature regarding the man agement of CSF leaks. When grading the current evidence, it is important to consider that performing a double-blind randomized controlled trial for surgical treatment in many circumstances is not possible. For this reason many current practices involving the management of CSF leaks are based on case series and first principles. However, we believe that many areas can and should be effectively studied to improve the evidence base in managing CSF leaks. Some of the best evidence regarding managing CSF leaks, to date, includes the use of prophylactic antibiotics. The preponderance of the evidence appears to favor avoiding

the routine use of prophylactic antibiotics. The evidence, however, is sparse with regard to the perioperative manage ment of the patient, including intraoperative and postoper ative use of antibiotics. Further research needs to examine the value of antibiotics in the intraoperative and postoper ative period. The aggregate grade of evidence for techniques and ma terials for the endoscopic repair of CSF leaks is primar ily comprised of low-level studies. This should be kept in mind when reviewing the results and particularly the meta analyses that are based on these low-level investigations. Lumbar drains, although once commonly used in CSF leak repair, are now infrequently used except when intracranial hypertension is suspected. The current level of evidence sug gests that their routine use has no defined benefit besides intracranial pressure monitoring in spontaneous CSF leak patients and carries the potential for serious complications; for this reason we strongly recommend against the routine use of lumbar drains except in this setting. The use of fat, bone grafts, allografts, and xenografts for endoscopic repair of CSF leaks show no clear benefit over other materials and can be used at the surgeons’ discre tion. It should be kept in mind when repairing CSF leaks that fat and bone grafting have associated donor-site mor bidity and their harvest increases operative time and costs. Free mucosal grafts, if used from previously resected middle turbinate tissue, require no additional time or cost. There is limited donor-site morbidity when a free mucosal graft is taken from the floor of the nose or posterior nasal septum, yet it is associated with increased operative time. We do rec ommend repairing larger skull-base defects and high-flow leaks with a vascular nasoseptal flap because the evidence shows improved outcomes. 7 The use of glues and dural sealants are commonly employed at the time of surgery be cause conceptually, it is plausible that their use helps seal the defect and hold the graft in place. The increased cost and limited evidence obtained from clinical studies should be considered when using sealants and dural glues, as there is also an associated cost with their use. Postoperative management varies widely from surgeon to surgeon and is based primarily on expert opinion and first principles. The nasal packing following CSF leak repair is commonly used, although the evidence supporting this is limited. The concern of not using a nasal pack (bolster) is the loss of contact of the graft to the skull base preventing adequate sealing of the defect. Further, it is unknown what type of packs should be placed and the length of time for which they should be left. Medication to reduce or pre vent intracranial pressure including antitussives, antiemet ics, and stool softeners are commonly used following CSF leak repair, although the evidence supporting this practice is limited. Other common postoperative management techniques, including bed rest, necessary duration of restricted activ ity, air travel, and when patients can resume using their CPAP postoperatively have no clinical evidence at this time.

International Forum of Allergy & Rhinology, Vol. 6, No. 1, January 2016

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