Pathophysiology of iatrogenic and traumatic skull base injury.

Traumatic skull base injuries can be divided into iatrogenic injuries from surgery and accidental traumatic injuries. The most common cause of iatrogenic skull base injury is endoscopic sinus surgery. The reported rate of cerebrospinal fluid (CSF) leak as a complication of endoscopic sinus surgery is less than 1%. Intraoperative injury most commonly occurs at the ethmoid roof and the lateral lamella of the cribiform plate. Case complexity, such as revision surgery, as well as surgical experience has been shown to be a contributing factor to iatrogenic CSF leaks during endoscopic sinus surgery. Other causes of iatrogenic CSF leaks include endoscopic skull base and open neurosurgical procedures. CSF leak occurs in 2.6% of all closed head traumas and is more likely in the case of a definitive skull base fracture. The majority of accidental trauma CSF leaks can be managed conservatively, but those that persist beyond a week are typically managed surgically to avoid the risk of meningitis.