Blood flow velocity in the middle cerebral artery during transnasal endoscopic skull base surgery performed in controlled hypotension

Abstract

During transnasal endoscopic procedures performed in moderate hypotension, in addition to significant drop of blood flow velocity to values well below the normal reference range, a divergent reduction of systolic and diastolic velocity was detected. Since divergent systolic and diastolic velocity may indicate an early phase of cerebral autoregulation compromise, and the decrease of mean blood flow velocity in MCA corresponds with a decrease of cerebral blood flow, further investigations in this field seem warranted.

Hypotension during transsphenoidal pituitary surgery associated with increase in plasma levels of brain injury markers

“…To our knowledge, there is only one previous study that has studied the impact of hypotension on biomarker release during intracranial surgery. In this study, deliberate hypotension was associated with increased levels of the brain injury biomarker neuron‐specific enolase 14 …”

“…In this study, deliberate hypotension was associated with increased levels of the brain injury biomarker neuron-specific enolase. 14 Our data suggest that patients undergoing pituitary surgery may have an increased sensitivity to intraoperative hypotension. However, given the scarcity of the available evidence on the relationship between intraoperative hypotension and postoperative levels of brain injury biomarkers, whether our findings are relevant for pituitary surgery alone, intracranial surgery more generally, or for extracranial surgery as well, remains to be elucidated.…”

“…Only one previous study has investigated the association between IOH and biomarkers of brain injury in neurosurgery. In that study, an association was found between IOH and an increase in neuron‐specific enolase (NSE) in skull base surgery following deliberate hypotension 14 …”

“…In that study, an association was found between IOH and an increase in neuronspecific enolase (NSE) in skull base surgery following deliberate hypotension. 14 Since hypotension may increase vulnerability to surgical manipulation and since IOH has been associated with elevated postoperative levels of brain injury biomarkers following neurological surgery, it is possible that this could be a contributing mechanism to brain injury following pituitary surgery. Therefore, this study aimed to test the hypothesis that the degree and duration of intraoperative hypotension during pituitary surgery were associated with increased plasma concentrations of the brain injury biomarkers tau, GFAP, and NFL.…”

Mild to severe controlled hypotension with nicardipine can maintain intraoperative microcirculatory cerebral blood flow and oxygenation in pigs

“…Although the study reported a low incidence of postoperative mortality and serious adverse events, it is important to note that the enrolled patients were relatively healthy (ASA grade I-II). Studies have shown that controlled hypotension does not cause neurological dysfunction [3]. However, it can lead to a signi cant increase in postoperative neuron-speci c enolase (NSE), a marker of brain injury.…”