Direct observation during surgery shows preservation of cerebral microcirculation in patients with traumatic brain injury.

Objective: To describe the alterations of the cortical microcirculation of the brain (blood flow and vessel density) in TBI patients who and compare them with a control group.

Methods: Prospective and observational study in a third-level university hospital. Cortical microcirculation in the brain was directly observed using sidestream dark-field (SDF) imaging in 14 patients who underwent surgery: 5 subdural hematomas (SDH) and 9 parenchymal lesions (contusions/hematomas). In this last set of patients, images were recorded in the "pericontusional" areas and in the "surrounding" brain (areas that were as far from the lesion as the craniotomy allowed). These patients were compared to five patients who underwent craniotomy for a disease that did not affect the cortex.

Results: There were fewer "pericontusional" images that could be analyzed due to the presence of subarachnoid hemorrhage. The proportion or perfused vessels was similar in all groups: control 99.5% ± 1.3%; SDH 98.6% ± 2.4%; "pericontusional" area 98.2% ± 2.4%; "surrounding" area 98.4% ± 2.5% (p = 0.145). The perfused vessel density index was smaller in the "pericontusional" area: control 6.5 ± 1.6 l/mm; SDH 6.5 ± 2.5 l/mm; "pericontusional" area 5.4 ± 2.6 l/mm; "surrounding" 6.6 ± 2.1 l/mm (p = 0.07).

Conclusions: Although the analysis of pericontusional zone was difficult, there were fewer vessels than in the controls and there was no change in the flow. In the surrounding zone and in patients with SDH, we did not document alterations in the microcirculation. Direct imaging of cerebral microcirculation in TBI patients showed that despite serious brain injury the cerebral microcirculation was remarkably well preserved.