Effective ICP Reduction by Decompressive Craniectomy in Patients with Severe Traumatic Brain Injury Treated by an ICP-Targeted Therapy

Abstract

Severe traumatic brain injury (TBI) is one of the major causes of death in younger age groups. In Umeå, Sweden, an intracranial pressure (ICP) targeted therapy protocol, the Lund concept, has been used in treatment of severe TBI since 1994. Decompressive craniectomy is used as a protocolguided treatment step. The primary aim of the investigation was to study the effect of craniectomy on ICP changes over time in patients with severe TBI treated by an ICP-targeted protocol. In this retrospective study, all patients treated for severe TBI during 1998-2001 who fulfilled the following inclusion criteria were studied: GCS Յ 8 at intubation and sedation, first recorded cerebral perfusion pressure (CPP) of Ͼ10 mm Hg, arrival within 24 h of trauma, and need of intensive care for Ͼ72 h. Craniectomy was performed when the ICP could not be controlled by evacuation of hematomas, sedation, ventriculostomy, or low-dose pentothal infusion. Ninety-three patients met the inclusion criteria. Mean age was 37.6 years. Twenty-one patients underwent craniectomy as a treatment step. We found a significant reduction of the ICP directly after craniectomy, from 36.4 mm Hg (range, 18-80 mm Hg) to 12.6 mm Hg (range, 2-51 mm Hg). During the following 72 h, we observed an increase in ICP during the first 8-12 h after craniectomy, reaching approximately 20 mm Hg, and later levelling out at approximately 25 mm Hg. The reduction of ICP was statistically significant during the 72 h. The outcome as measured by Glasgow Outcome Scale (GOS) did not significantly differ between the craniectomized group (DC) and the non-craniectomized group (NDC). The outcome was favorable (GOS 5-4) in 71% in the craniectomized group, and in 61% in the noncraniectomized group. Craniectomy is a useful tool in achieving a significant reduction of ICP over time in TBI patients with progressive intracranial hypertension refractory to medical therapy. The procedure seems to have a satisfactory effect on the outcome, as demonstrated by a high rate of favorable outcome and low mortality in the craniectomized group, which did not significantly differ compared with the non-craniectomized group.

Complications of decompressive craniectomy for traumatic brain injury

“…2,87 As a rescue therapy, decompressive craniectomy has been shown to reliably abort progressive increases in ICP. 59,89 Decompressive craniectomy also brings about changes in CBF and CSF dynamics. 7,20,24,96,97 Cine MR imaging studies have demonstrated impaired CSF flow across the craniovertebral junction at the skull base, which improves following cranioplasty repair of the skull defect.…”

“…96 In addition, loss of resistance in brain tissue lacking a protective skull invokes a higher hydrostatic pressure gradient that may permit transcapillary leakage of edema fluid. 59 Brain edema following decompressive craniectomy has been modeled in animal studies of injury using Evans blue dye extravasation. 15,25,69 Cooper et al 15 found a 7-fold increase in edema formation as determined by Evans blue dye extravasation following craniectomy.…”

“…4). 59 Large bone decompression allows the brain to expand outward without constriction and minimizes the risk of venous ischemia. A technique of inserting "vascular cushions" adjacent to large draining veins at the craniectomy margin has been reported to reduce the risk of venous ischemia.…”

Traumatic brain injury in pediatric patients: evidence for the effectiveness of decompressive surgery

“…Reduction of refractory ICP has been shown to be a major predictor of mortality following TBI, 21,25,31,42 and many studies have confirmed the positive effects of craniectomy on reducing ICP following TBI. 1,37,49,50 However, few randomized controlled studies exist that specifically address the effectiveness of craniectomy in pediatric populations to improve clinical outcome. In most current adult and pediatric studies, refractory ICP hypertension is often defined as ICP > 20 mm Hg for some defined time period.…”

Role of post-decompressive hydrocephalus in patients with malignant cerebral infarction

“…Decompressive craniectomy (DC) has been accepted as a therapeutic strategy for patients with medically refractory increased intracranial pressure (ICP) secondary to severe traumatic brain injury (TBI), malignant middle cerebral artery (MCA) or internal cerebral artery (ICA) infarction, large hypertensive intracerebral hemorrhage (ICH), high-grade aneurysmal subarachnoid hemorrhage and severe cerebral venous sinus thrombosis (5,7,12,13,14,17,20).…”