Intracranial pressure and cerebral oxygenation changes after decompressive craniectomy in a child with traumatic brain swelling

Duraplasty in Traumatic Thoracic Spinal Cord Injury: Impact on Spinal Cord Hemodynamics, Tissue Metabolism, Histology, and Behavioral Recovery Using a Porcine Model

After acute traumatic spinal cord injury (SCI), the spinal cord can swell to fill the subarachnoid space and become compressed by the surrounding dura. In a porcine model of SCI, we performed a duraplasty to expand the subarachnoid space around the injured spinal cord and evaluated how this influenced acute intraparenchymal hemodynamic and metabolic responses, in addition to histological and behavioral recovery. Female Yucatan pigs underwent a T10 SCI, with or without duraplasty. Using microsensors implanted into the spinal cord parenchyma, changes in blood flow (ΔSCBF), oxygenation (ΔPO₂), and spinal cord pressure (ΔSCP) during and after SCI were monitored, alongside metabolic responses. Behavioral recovery was tested weekly using the Porcine Injury Behavior Scale (PTIBS). Thereafter, spinal cords were harvested for tissue sparing analyses. In both duraplasty and non-animals, the ΔSCP increased ∼5 mm Hg in the first 6 h post-injury. After this, the SCP appeared to be slightly reduced in the duraplasty animals, although the group differences were not statistically significant after controlling for injury severity in terms of impact force. During the first seven days post-SCI, the ΔSCBF or ΔPO₂ values were not different between the duraplasty and control animals. Over 12 weeks, there was no improvement in hindlimb locomotion as assessed by PTIBS scores and no reduction in tissue damage at the injury site in the duraplasty animals. In our porcine model of SCI, duraplasty did not provide any clear evidence of long-term behavioral or tissue sparing benefit after SCI.

Early Decompressive Craniectomy as Management for Severe Traumatic Brain Injury in the Pediatric Population: A Comprehensive Literature Review

BACKGROUND

Severe traumatic brain injuries (TBIs) are a principal cause of neurologic dysfunction and death in the pediatric population. After medical management, the second-tier treatment is decompressive craniectomy in cases of intractable intracranial pressure (ICP) elevation. This literature review offers evidence of early (within 24 hours) and ultraearly (6-12 hours) decompressive craniectomy as an effective form of management for severe TBI in the pediatric population.

METHODS

We conducted a literature review of articles published from 1996 to 2019 to elucidate neurologic outcomes after early decompressive craniectomy in pediatric patients who suffered a severe TBI. Time to decompressive craniectomy and neurologic outcomes were recorded and reported descriptively. Qualitative data describe clinically important correlations between pre- and postoperative ICP levels and improved postoperative neurologic outcomes.

RESULTS

Seventy-eight patients were included in this study. The median age of patients at diagnosis was 10 years of age (range, 1 months to 19 years). Median admission Glasgow Coma Scale score was 5 (range, 3-8). Time to decompressive craniectomy ranged from 1 to 24 hours. Median peak preoperative ICP was 40 (range, 3-90; n = 49). Median postoperative ICP was 20 (range, 0-80; n = 33). Median Glasgow Outcome Scale (GOS) score at discharge was 2 (range, 1-5; n = 11). Median GOS score at 3- and 6-month follow-up was 3 (range, 1-5; n = 11). Median GOS score at 7- to 23-month follow-up was 4 (range, 1-5; n = 29). Median GOS score at 24- to 83-month follow-up was 4 (range, 1-5; n = 31). Median modified Rankin Scale score at discharge was 3 (range, 2-4; n = 6). Median modified Rankin Scale score at 6- to 48-month follow-up was 2 (range, 0-3; n = 6). Median Rancho Los Amigos Scale (RLAS) score at discharge was 6 (range, 4-8; n = 5). Median RLAS score at 6-month follow-up was 10 (range, 8-10; n = 5).

CONCLUSIONS

Early (within 24 hours), with consideration of ultraearly (within 6-12 hours), decompressive craniectomy for severe TBI should be offered to pediatric patients in settings with refractory ICP elevation. Reduction of ICP allows for prompt disruption of pathophysiologic cascades and improved neurologic outcomes.

Decompressive craniectomy for the treatment of high intracranial pressure in closed traumatic brain injury

BACKGROUND

High intracranial pressure (ICP) is the most frequent cause of death and disability after severe traumatic brain injury (TBI). It is usually treated with general maneuvers (normothermia, sedation, etc.) and a set of first-line therapeutic measures (moderate hypocapnia, mannitol, etc.). When these measures fail, second-line therapies are initiated, which include: barbiturates, hyperventilation, moderate hypothermia, or removal of a variable amount of skull bone (secondary decompressive craniectomy).

OBJECTIVES

To assess the effects of secondary decompressive craniectomy (DC) on outcomes of patients with severe TBI in whom conventional medical therapeutic measures have failed to control raised ICP.

SEARCH METHODS

The most recent search was run on 8 December 2019. We searched the Cochrane Injuries Group's Specialised Register, CENTRAL (Cochrane Library), Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase Classic + Embase (OvidSP) and ISI Web of Science (SCI-EXPANDED & CPCI-S). We also searched trials registries and contacted experts.

SELECTION CRITERIA

We included randomized studies assessing patients over the age of 12 months with severe TBI who either underwent DC to control ICP refractory to conventional medical treatments or received standard care.

DATA COLLECTION AND ANALYSIS

We selected potentially relevant studies from the search results, and obtained study reports. Two review authors independently extracted data from included studies and assessed risk of bias. We used a random-effects model for meta-analysis. We rated the quality of the evidence according to the GRADE approach.

MAIN RESULTS

We included three trials (590 participants). One single-site trial included 27 children; another multicenter trial (three countries) recruited 155 adults, the third trial was conducted in 24 countries, and recruited 408 adolescents and adults. Each study compared DC combined with standard care (this could include induced barbiturate coma or cooling of the brain, or both). All trials measured outcomes up to six months after injury; one also measured outcomes at 12 and 24 months (the latter data remain unpublished). All trials were at a high risk of bias for the criterion of performance bias, as neither participants nor personnel could be blinded to these interventions. The pediatric trial was at a high risk of selection bias and stopped early; another trial was at risk of bias because of atypical inclusion criteria and a change to the primary outcome after it had started. Mortality: pooled results for three studies provided moderate quality evidence that risk of death at six months was slightly reduced with DC (RR 0.66, 95% CI 0.43 to 1.01; 3 studies, 571 participants; I2 = 38%; moderate-quality evidence), and one study also showed a clear reduction in risk of death at 12 months (RR 0.59, 95% CI 0.45 to 0.76; 1 study, 373 participants; high-quality evidence). Neurological outcome: conscious of controversy around the traditional dichotomization of the Glasgow Outcome Scale (GOS) scale, we chose to present results in three ways, in order to contextualize factors relevant to clinical/patient decision-making. First, we present results of death in combination with vegetative status, versus other outcomes. Two studies reported results at six months for 544 participants. One employed a lower ICP threshold than the other studies, and showed an increase in the risk of death/vegetative state for the DC group. The other study used a more conventional ICP threshold, and results favoured the DC group (15.7% absolute risk reduction (ARR) (95% CI 6% to 25%). The number needed to treat for one beneficial outcome (NNTB) (i.e. to avoid death or vegetative status) was seven. The pooled result for DC compared with standard care showed no clear benefit for either group (RR 0.99, 95% CI 0.46 to 2.13; 2 studies, 544 participants; I2 = 86%; low-quality evidence). One study reported data for this outcome at 12 months, when the risk for death or vegetative state was clearly reduced by DC compared with medical treatment (RR 0.68, 95% CI 0.54 to 0.86; 1 study, 373 participants; high-quality evidence). Second, we assessed the risk of an 'unfavorable outcome' evaluated on a non-traditional dichotomized GOS-Extended scale (GOS-E), that is, grouping the category 'upper severe disability' into the 'good outcome' grouping. Data were available for two studies (n = 571). Pooling indicated little difference between DC and standard care regarding the risk of an unfavorable outcome at six months following injury (RR 1.06, 95% CI 0.69 to 1.63; 544 participants); heterogeneity was high, with an I2 value of 82%. One trial reported data at 12 months and indicated a clear benefit of DC (RR 0.81, 95% CI 0.69 to 0.95; 373 participants). Third, we assessed the risk of an 'unfavorable outcome' using the (traditional) dichotomized GOS/GOS-E cutoff into 'favorable' versus 'unfavorable' results. There was little difference between DC and standard care at six months (RR 1.00, 95% CI 0.71 to 1.40; 3 studies, 571 participants; low-quality evidence), and heterogeneity was high (I2 = 78%). At 12 months one trial suggested a similar finding (RR 0.95, 95% CI 0.83 to 1.09; 1 study, 373 participants; high-quality evidence). With regard to ICP reduction, pooled results for two studies provided moderate quality evidence that DC was superior to standard care for reducing ICP within 48 hours (MD -4.66 mmHg, 95% CI -6.86 to -2.45; 2 studies, 182 participants; I2 = 0%). Data from the third study were consistent with these, but could not be pooled. Data on adverse events are difficult to interpret, as mortality and complications are high, and it can be difficult to distinguish between treatment-related adverse events and the natural evolution of the condition. In general, there was low-quality evidence that surgical patients experienced a higher risk of adverse events.

AUTHORS' CONCLUSIONS

Decompressive craniectomy holds promise of reduced mortality, but the effects of long-term neurological outcome remain controversial, and involve an examination of the priorities of participants and their families. Future research should focus on identifying clinical and neuroimaging characteristics to identify those patients who would survive with an acceptable quality of life; the best timing for DC; the most appropriate surgical techniques; and whether some synergistic treatments used with DC might improve patient outcomes.

Pia Mater Significantly Contributes to Spinal Cord Intraparenchymal Pressure in a Simulated Model of Edema

STUDY DESIGN

Intraparenchymal pressure (IPP) measurements in an in vitro cadaveric model of CNS edema.

OBJECTIVE

To assess the contribution of pia mater to IPP and the effect of piotomy.

SUMMARY OF BACKGROUND DATA

Multicenter randomized control trials have shown that decompression with durotomy/duroplasty significantly decreases intracranial pressure (ICP). There is a paucity of evidence regarding the effectiveness of decompression of the spinal cord by piotomy.

METHODS

The supratentorial brain and spinal cord were removed from six fresh cadavers. Dura and arachnoid mater were removed. ICP monitors were placed bilaterally in the frontal and parietal lobes, and centrally in the cervical and thoracic spinal cord. To simulate edema, specimens were submerged in hypotonic solution. IPP was recorded for 5 days. A complete dorsal midline piotomy was performed on the spinal cord and resulting IPP was recorded.

RESULTS

Brain and spinal cord both increased in weight. IPP significantly increased in both brain and spinal cord. The IPP increase within the spinal cord was substantially greater (averages: all four lobes = 4.0 mm Hg; cervical = 73.7 mm Hg; thoracic = 49.3 mm Hg). After piotomy, cervical and thoracic spinal cord IPP decreased immediately (avg. postpiotomy IPP = 9.7 and 10.3, respectively).

CONCLUSION

There were differential effects on brain and spinal cord IPP. Brain IPP increased only slightly, possibly because of the absence of the cranium and dura mater. In contrast, spinal cord IPP increased substantially even in the absence of the laminae, dura, and arachnoid mater. Piotomy immediately and dramatically reduced spinal cord IPP. These data are consistent with the hypothesis that spinal cord IPP is primarily dependent on constraints imposed by the pia mater. Conversely, in the absence of the cranium and dura mater, the sulci may permit the pia-invested brain to better accommodate edema without significant increases in IPP.

LEVEL OF EVIDENCE

N/A.

Decompressive craniectomy in children: single-center series and systematic review

BACKGROUND

Decompressive craniectomy (DC) is performed as a life-saving procedure in patients with intractably increased intracranial pressure after traumatic brain injury, bleeding, cerebral infarction, or brain swelling of other causes. However, the application of DC is as controversial in the pediatric population as it is in adults.

OBJECTIVE

To find factors influencing the outcome in pediatric patients who underwent DC because of sustained high intracranial pressure.

METHODS

Between April 2000 and December 2009, 34 pediatric patients (age 0-18 years) underwent DC. Patients were stratified according to the indication for DC. Outcome was assessed according to the modified Rankin Scale score at 6 months. MEDLINE was searched for published studies or reports of DC in pediatric patients to gain a larger population. Two reviewers independently extracted data.

RESULTS

Literature data, including the current series, revealed a total of 172 pediatric patients. Overall, a favorable outcome was achieved in 106 of 172 patients (62%). A favorable outcome was achieved in 25 of 36 patients without traumatic brain injury vs 81 of 136 patients with traumatic brain injury (69% vs 60%). Patients without signs of cerebral herniation had a better outcome than patients with unilateral or bilateral dilated pupils (73% vs 60% vs 45%, respectively).

CONCLUSION

The current data indicate that DC in children with traumatic or nontraumatic brain swelling might be warranted, regardless of the underlying cause. Despite mydriasis, a favorable outcome might be achieved in a significant number of pediatric patients. Nevertheless, careful individual decision making is needed for each patient, especially when signs of cerebral herniation have persisted for a long time.

Pediatric neurocritical care

Pediatric neurocritical care is an emerging multidisciplinary field of medicine and a new frontier in pediatric critical care and pediatric neurology. Central to pediatric neurocritical care is the goal of improving outcomes in critically ill pediatric patients with neurological illness or injury and limiting secondary brain injury through optimal critical care delivery and the support of brain function. There is a pressing need for evidence based guidelines in pediatric neurocritical care, notably in pediatric traumatic brain injury and pediatric stroke. These diseases have distinct clinical and pathophysiological features that distinguish them from their adult counterparts and prevent the direct translation of the adult experience to pediatric patients. Increased attention is also being paid to the broader application of neuromonitoring and neuroprotective strategies in the pediatric intensive care unit, in both primary neurological and primary non-neurological disease states. Although much can be learned from the adult experience, there are important differences in the critically ill pediatric population and in the circumstances that surround the emergence of neurocritical care in pediatrics.

Technical considerations in decompressive craniectomy in the treatment of traumatic brain injury

Refractory intracranial hypertension is a leading cause of poor neurological outcomes in patients with severe traumatic brain injury. Decompressive craniectomy has been used in the management of refractory intracranial hypertension for about a century, and is presently one of the most important methods for its control. However, there is still a lack of conclusive evidence for its efficacy in terms of patient outcome. In this article, we focus on the technical aspects of decompressive craniectomy and review different methods for this procedure. Moreover, we review technical improvements in large decompressive craniectomy, which is currently recommended by most authors and is aimed at increasing the decompressive effect, avoiding surgical complications, and facilitating subsequent management. At present, in the absence of prospective randomized controlled trials to prove the role of decompressive craniectomy in the treatment of traumatic brain injury, these technical improvements are valuable.

Controversies of prophylactic hypothermia and the emerging use of brain tissue oxygen tension monitoring and decompressive craniectomy in traumatic brain-injured children

BACKGROUND

Despite being the leading cause of death and disability in the paediatric population, traumatic brain injury (TBI) in this group is largely understudied. Clinical practice within the paediatric intensive care unit (PICU) has been based upon adult guidelines however children are significantly different in terms of mechanism, pathophysiology and consequence of injury.

AIM

To review TBI management in the PICU and gain insight into potential management strategies.

METHOD

To conduct this review, a literature search was conducted using MEDLINE, PUBMED and The Cochrane Library using the following key words; traumatic brain injury; paediatric; hypothermia. There were no date restrictions applied to ensure that past studies, whose principles remain current were not excluded.

RESULTS

Three areas were identified from the literature search and will be discussed against current acknowledged treatment strategies: Prophylactic hypothermia, brain tissue oxygen tension monitoring and decompressive craniectomy.

CONCLUSION

Previous literature has failed to fully address paediatric specific management protocols and we therefore have little evidence-based guidance. This review has shown that there is an emerging and ongoing trend towards paediatric specific TBI research in particular the area of moderate prophylactic hypothermia (MPH).

Effects of unilateral decompressive craniectomy on patients with unilateral acute post-traumatic brain swelling after severe traumatic brain injury

Introduction

Acute post-traumatic brain swelling (BS) is one of the pathological forms that need emergent treatment following traumatic brain injury. There is controversy about the effects of craniotomy on acute post-traumatic BS. The aim of the present clinical study was to assess the efficacy of unilateral decompressive craniectomy (DC) or unilateral routine temporoparietal craniectomy on patients with unilateral acute post-traumatic BS.

Methods

Seventy-four patients of unilateral acute post-traumatic BS with midline shifting more than 5 mm were divided randomly into two groups: unilateral DC group (n = 37) and unilateral routine temporoparietal craniectomy group (control group, n = 37). The vital signs, the intracranial pressure (ICP), the Glasgow outcome scale (GOS), the mortality rate and the complications were prospectively analysed.

Results

The mean ICP values of patients in the unilateral DC group at hour 24, hour 48, hour 72 and hour 96 after injury were much lower than those of the control group (15.19 +/- 2.18 mmHg, 16.53 +/- 1.53 mmHg, 15.98 +/- 2.24 mmHg and 13.518 +/- 2.33 mmHg versus 19.95 +/- 2.24 mmHg, 18.32 +/- 1.77 mmHg, 21.05 +/- 2.23 mmHg and 17.68 +/- 1.40 mmHg, respectively). The mortality rates at 1 month after treatment were 27% in the unilateral DC group and 57% in the control group (p = 0.010). Good neurological outcome (GOS Score of 4 to 5) rates 1 year after injury for the groups were 56.8% and 32.4%, respectively (p = 0.035). The incidences of delayed intracranial hematoma and subdural effusion were 21.6% and 10.8% versus 5.4% and 0, respectively (p = 0.041 and 0.040).

Conclusions

Our data suggest that unilateral DC has superiority in lowering ICP, reducing the mortality rate and improving neurological outcomes over unilateral routine temporoparietal craniectomy. However, it increases the incidence of delayed intracranial hematomas and subdural effusion, some of which need secondary surgical intervention. These results provide information important for further large and multicenter clinical trials on the effects of DC in patients with acute post-traumatic BS.

Trial registration

ISRCTN14110527

Brain tissue oxygenation changes in children during the first 24 h following head injury

AIM

The aim of this study is to assess the changes of brain tissue oxygen levels in children during the first 24 h following head injury and its correlation with changes of intracranial pressure and clinical outcome.

METHOD

Invasive monitoring of partial brain tissue oxygen tension (PbtO(2)) using the Licox (Integra Neurosciences, Plainsboro, NJ, USA) oxygen probe was performed in children with severe head injury requiring ventilation, during the years 2002-2005. The study focused in the recordings of the first 24 h following injury.

RESULTS

There were four patients (three males, one female) with an age range of 2-12 years. All injuries were due to motor vehicle accidents. The Glasgow Coma Score ranged from 5 to 9. All patients had diffuse axonal injuries on Computed Tomography scan. One patient underwent a bilateral decompressive craniectomy. The total duration of monitoring was 567.84 h. During the first 24 h, the mean PbtO(2) was 4.2 mmHg, 12.7 mmHg, 21.8 mmHg, and 25.1 mmHg in each patient. Fifteen episodes of ICP>20 mmHg were seen in the first 24 h of monitoring. Nine of these episodes were accompanied by a reduction in PbtO(2) levels. The Glasgow Outcome Score at 1 year was good recovery (GOS 3) in three patients and severe disability in one patient. There were no complications from the monitoring.

CONCLUSIONS

In children with head injury, rise in ICP may be accompanied by fall in PbtO(2). However, low brain oxygen levels during the first 24 h following head injury may not correlate necessarily with poor outcome.

Continuous monitoring and intervention for cerebral ischemia in tuberculous meningitis

OBJECTIVE

Tuberculous meningitis (TBM) is a massive global problem. The mortality and morbidity associated with the severe form of the disease are exceptionally high. Even when increased intracranial pressure is treated and full conventional therapy is commenced, cerebral ischemia can develop and is associated with a particularly poor prognosis. We sought to evaluate our experience with two patients with severe TBM and cerebral oxygenation monitoring.

DESIGN

Case report.

SETTING

Red Cross Children's Hospital, Cape Town.

PATIENTS

Two comatose patients with TBM.

INTERVENTIONS

Targeted interventions against low cerebral oxygenation in one patient.

MEASUREMENTS AND MAIN RESULTS

Cerebral tissue oxygenation (Ptio2) was measured. In both patients, Ptio2 monitoring demonstrated delayed cerebral ischemia despite the institution of full conventional therapy and the control of intracranial pressure. These data confirm that the vascular involvement in TBM is potentially progressive and that failure to diagnose infarction initially is not merely due to a delay in the radiologic appearance. The first patient developed extensive infarction, consistent with Ptio2 readings, and subsequently died after treatment withdrawal. Intervention in the second patient successfully reversed a precipitous decline of the Ptio2 readings and may have prevented infarction in this patient.

CONCLUSIONS

The development of delayed cerebral ischemia in TBM despite treatment is confirmed in these two patients. The reversal of a decline in Ptio2 readings suggests a possible benefit for cerebral oxygenation monitoring in selected patients with severe TBM.

Decompressive craniectomy for the treatment of refractory high intracranial pressure in traumatic brain injury

BACKGROUND

High intracranial pressure (ICP) is the most frequent cause of death and disability after severe traumatic brain injury (TBI). High ICP is treated by general maneuvers (normothermia, sedation etc) and a set of first line therapeutic measures (moderate hypocapnia, mannitol etc). When these measures fail to control high ICP, second line therapies are started. Among these, second line therapies such as barbiturates, hyperventilation, moderate hypothermia or removal of a variable amount of skull bone (known as decompressive craniectomy) are used.

OBJECTIVES

To assess the effects of secondary decompressive craniectomy (DC) on outcome and quality of life in patients with severe TBI in whom conventional medical therapeutic measures have failed to control raised ICP.

SEARCH STRATEGY

We searched the Cochrane Injuries Group's Trial Register, CENTRAL, MEDLINE, EMBASE, Best Evidence, Clinical Practice Guidelines, PubMed, CINAHL, the National Research Register and Google Scholar. We also handsearched relevant conference proceedings and contacted experts in the field and the authors of included studies.

SELECTION CRITERIA

Randomized or quasi-randomized studies assessing patients over the age of 12 months with a severe TBI who underwent DC to control ICP refractory to conventional medical treatments.

DATA COLLECTION AND ANALYSIS

Two authors independently examined the electronic search results for reports of possibly relevant trials and for retrieval in full. One author applied the selection criteria, performed the data extraction and assessed methodological quality. Study authors were contacted for additional information.

MAIN RESULTS

We found one trial with 27 participants conducted in the pediatric population (>18 years). DC was associated with a risk ratio (RR) for death of 0.54 (95% CI 0.17 to 1.72), and RR of 0.54 for death, vegetative status or severe disability 6 to 12 months after injury (95% CI 0.29 to 1.07).

AUTHORS' CONCLUSIONS

There is no evidence to support the routine use of secondary DC to reduce unfavourable outcome in adults with severe TBI and refractory high ICP. In the pediatric population DC reduces the risk of death and unfavourable outcome. Despite the wide confidence intervals for death and the small sample size of the only study identified, this treatment maybe justified in patients below the age of 18 when maximal medical treatment has failed to control ICP. To date, there are no results from randomised trials to confirm or refute the effectiveness of DC in adults. However, the results of non-randomized trials and controlled trials with historical controls involving adults, suggest that DC may be a useful option when maximal medical treatment has failed to control ICP. There are two ongoing randomized controlled trials of DC (Rescue ICP and DECRAN) that may allow further conclusions on the efficacy of this procedure in adults.