Retrospective Study of Skull Base Fracture: A Study of Incidents, Complications, Management, and Outcome Overview from Trauma-One-Level Institute over 5 Years.

Introduction: Fractures of the skull base (SB) comprise a small portion of overall head fractures (3.5-24%) and even a smaller portion of overall head injuries (4%); however, the outcomes for these injuries carry much morbidity and mortality, including but not limited to: CSF leak, fistula formation, cranial nerve (CN) injury, vascular injury, and infection. We evaluated the presence of these injuries with the rate of surgical intervention performed, hypothesizing that the need for an SB surgical approach in managing such patients in a trauma-one-level hospital is relatively rare.

Methods: A 5-year-retrospective study of patient records from University Medical Center in Tucson was conducted. A total of 1606 patients had SB fractures entailing frontal, orbital, ethmoid, sphenoid, temporal, occipital, and clival bone.

Patients’ charts were reviewed for demographic information, cause of injury, associated injuries, radiologic studies, Glasgow Coma Scale score, length of hospitalization, surgical interventions, complications of SB fractures, and mortalities.

Results: Frequency of SB fractures was 12.14% of all head injuries and 20.21% of all skull fractures. Temporal bone was most commonly involved among all SB fractures (40%), followed by orbital roof (24.1%), sphenoid (22.6%), occipital (15.4%), ethmoid (10.8%), and clival bone (1.03%).

Temporal and orbital bone fractures were witnessed in isolation, whereas fractures of ethmoid, sphenoid, and clival bones only occurred in conjunction with other fractures and were commonly accompanied by facial fractures (92%); SB fractures more commonly occurred in conjunction with facial fractures (25%) then without facial fractures was (2.9%.)

From 27 cases of SB fractures requiring intervention, 100% had involvement with three or more bone fractures, specifically of the incidence of CSF leaks needing repair. CSF leaks were most commonly seen in fractures of ethmoid (19.05%), followed by orbital (14.89%), temporal (14.1%), sphenoid (11.36%), and occipital bones (3.33%).

Fractures were complicated with CSF leak in 23.4% of patients; 55.6% of those patients needed interventions entailing surgery, EVD, and or LP placement. The majority of transient CN palsies also occurred in patients undergoing SB repair for various reasons (70%). No major vascular injuries were noted, and despite fractures extending to the carotid canal in 8.2% of all SB fractures, angiographic studies did not show carotid injuries. Rates of subdural, epidural, and subarachnoid hemorrhages were not evaluated.

Conclusion: CSF leaks have the highest incidence of complication in SB fractures, and their frequency is drastically increased in poly fractures of SB bones compared with single fracture. Risk of CN injury depends on the location of the SB fracture; in this study CN injuries were noted in anterior and middle SB injuries (CN II-VII), but none were noted in lower CNs, despite injury to posterior SB bones. In the case of major vessel injury, none were noted in this 5-year review, although the reported risk in the literature is 0.08-0.3%.

The rate of SB operations in treating any of the aforementioned complications is lower than performing decompressive craniotomies, EVD, or LP placement; thus surgical skill-set is rarely needed by a level-one trauma center, although the presence of such specialist is useful in select cases.