Decompressive Craniectomy Increases Brain Lesion Volume and Exacerbates Functional Impairment in Closed Head Injury in Mice

Abstract

Decompressive craniectomy has been widely used in patients with head trauma. The randomized clinical trial on an early decompression (DECRA) demonstrated that craniectomy did not improve the neurological outcome, in contrast to previous animal experiments. The goal of our study was to analyze the effect of decompressive craniectomy in a murine model of head injury. Male mice were assigned into the following groups: sham, decompressive craniectomy, closed head injury (CHI), and CHI followed by craniectomy. At 24 h post-trauma, animals underwent the Neurological Severity Score test (NSS) and Beam Balance Score test (BBS). At the same time point, magnetic resonance imaging was performed, and volume of edema and contusion was assessed, followed by histopathological analysis. According to NSS, animals undergoing both trauma and craniectomy presented the most severe neurological impairment. Also, balancing time was reduced in this group compared with sham animals. Both edema and contusion volume were increased in the trauma and craniectomy group compared with sham animals. Histopathological analysis showed that all animals that underwent trauma presented substantial neuronal loss. In animals treated with craniectomy after trauma, a massive increase of edema with hemorrhagic transformation of contusion was documented. Decompressive craniectomy applied after closed head injury in mice leads to additional structural and functional impairment. The surgical decompression via craniectomy promotes brain edema formation and contusional blossoming in our model. This additive effect of combined mechanical and surgical trauma may explain the results of the DECRA trial and should be explored further in experiments.

Changes in Posttraumatic Brain Edema in Craniectomy-Selective Brain Hypothermia Model Are Associated With Modulation of Aquaporin-4 Level

“…More so, the previous of the randomized craniectomy trials (DECRA) suggested a deleterious impact of surgical decompression on neurologic outcome ( 17 , 18 ). This conclusion could be supported by various experimental studies (including our own analyses), reporting increased structural damage and poorer functional recovery in animals treated by surgical decompression after head injury or subarachnoid hemorrhage ( 19 – 22 ).…”

“…Importantly, the proportion of both edema types changes within the posttraumatic course, with cytotoxic edema (demonstrated as hypointense ADC areas) being the predominant form of swelling during acute phase ( 54 – 56 ). This MRI-based observation was made also in experiments based on closed head injury (CHI) model ( 57 – 60 ) used in our laboratory ( 22 ).…”

Neuroinflammation, myelin and behavior: Temporal patterns following mild traumatic brain injury in mice

“…Another finding of our study is the modification of defense behaviors in the open-field and the elevated-plus maze test induced by the surgical procedure. It is now suggested in the literature that craniotomy itself could induce inflammation and edema [ 69 ]. Last but not the least, our unconditioned behavioral tests (neurological score, actimetry, open-field and elevated-plus maze) are able to reveal severe deficits of spontaneous behaviors, but could be insufficient to reveal complex behavioral disorders, involving integrative processes dependent of WMI, in this mild model of TBI.…”

Traumatic Brain Injury

“…They found that surgical decompression promoted brain edema formation and contusional blossoming and exacerbated functional impairments in mice with closed head injury. 84 The different results may be attributed to different injury severity from different TBI models. The outcomes of craniectomy application are highly correlated with the severity of the initial injury.…”