Cerebral Hemodynamic Changes in Severe Head Injury Patients Undergoing Decompressive Craniectomy

J Neurosurg Anesthesiol 2009;21:339–345

Objective: To assess the intracranial hemodynamic modifica- tions induced by a decompressive craniectomy (DC) after severe traumatic brain injury (TBI), using transcranial Doppler (TCD) ultrasonography and intracranial pressure (ICP) sensor. Mor- tality rate and neurological outcomes were also evaluated after this procedure.

Design: A prospective study was carried out on 26 TBI patients, measuring transcranial Doppler and ICP before, immediately after, and 48 hours after the DC, allowing for statistical analysis of hemodynamic changes. The mortality rate and the neuro- logical outcomes were assessed.

Measurements and Results: After DC, ICP decreased from 37±17 to 20±13mm Hg (P=0.0003). The global cerebral blood flow was modified with diastolic velocities rising from 23±15 to 31±13cm/s (P=0.0038) and a pulsatility index decreasing from 1.70±0.66 to 1.18±0.37 (P=0.0012). This normalization of the global cerebral hemodynamics after the DC was immediate, symmetric, and constant during the first 48 hours. Outcome was evaluated at 6 months: good recovery or moderate disability was observed in 11 patients (42%), persistent vegetative state in 7 patients (27%), and 8 patients died (31%).

Conclusions: The DC results in a significant, immediate, and durable improvement of ICP associated with a normalization of cerebral blood flow velocities in most TBI patients with refractory intracranial hypertension.