Decompressive craniectomy: technical note

Invasive and Noninvasive Techniques for Intracranial Pressure Monitoring After Decompressive Craniectomy: A Systematic Review and Meta-Analysis

The use of invasive or noninvasive intracranial pressure (ICP) monitoring post-decompressive craniectomy (DC) has been a continuous matter of debate. Accordingly, this meta-analysis aims to examine the existing evidence of both approaches and compare their impact among patients undergoing DC, guiding clinical decision-making in the management of elevated ICP. The databases used were Pubmed, Cochrane, Web of Science, and Embase. Inclusion criteria included: (1) English studies; (2) randomized and nonrandomized studies; (3) reporting on invasive OR noninvasive ICP monitoring after DC; (4) with at least one of the outcomes of interest: incidence of mortality, new cerebral hemorrhages, and the Glasgow Outcome Scale. The study followed the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Thirty-six studies were included in this meta-analysis, resulting in a sample of 1624 patients. One thousand two hundred eighty-six underwent invasive monitoring, and 338 underwent noninvasive methods. In the invasive group, a mortality rate of 17% (95% confidence interval [CI]: 12%-22%), a good outcome rate of 58% (95% CI: 38%-49%), a poor outcome rate of 42% (95% CI: 21%-62%), and an overall incidence of new hemorrhages of 4% (95% CI: 0%-8%) were found. Whereas in the noninvasive sample, a mortality rate of 20% (95% CI: 15%-26%) and a good outcome rate of 38% (95% CI: 25%-52%) were obtained. It seems that the effectiveness of invasive and noninvasive ICP monitoring methods are comparable in post-DC patients. While invasive monitoring remains gold standard, noninvasive methods offer a safer and cost-effective alternative, potentially improving post-DC patient care, and can mostly be used simultaneously with invasive methods.

Poroelastic modelling of brain tissue swelling and decompressive craniectomy treatment in ischaemic stroke

Brain oedema or tissue swelling that develops after ischaemic stroke can cause detrimental effects, including brain herniation and increased intracranial pressure (ICP). These effects can be reduced by performing a decompressive craniectomy (DC) operation, in which a portion of the skull is removed to allow swollen brain tissue to expand outside the skull. In this study, a poroelastic model is used to investigate the effect of brain ischaemic infarct size and location on the severity of brain tissue swelling. Furthermore, the model will also be used to evaluate the effectiveness of DC surgery as a treatment for brain tissue swelling after ischaemia. The poroelastic model consists of two equations: one describing the elasticity of the brain tissue and the other describing the changes in the interstitial tissue pressure. The model is applied on an idealized brain geometry, and it is found that infarcts with radius larger than approximately 14 mm and located near the lateral ventricle produce worse brain midline shift, measured through lateral ventricle compression. Furthermore, the model is also able to show the positive effect of DC treatment in reducing the brain midline shift by allowing part of the brain tissue to expand through the skull opening. However, the model does not show a decrease in the interstitial pressure during DC treatment. Further improvement and validation could enhance the capability of the proposed poroelastic model in predicting the occurrence of brain tissue swelling and DC treatment post ischaemia.

Decompressive Craniectomy for Pediatric Traumatic Brain Injury in Low-and-Middle Income and High Income Countries

Traumatic brain injury is one of the leading causes of mortality and morbidity in children worldwide. In severe cases, high intracranial pressure is the most frequent cause of death. When first-line medical management fails, the neurosurgical procedure of decompressive craniectomy (DC) has been proposed for controlling intracranial pressure and improving the long-term outcomes for children with severe traumatic brain injury. However, the use of this procedure is controversial. The evidence from clinical trials shows some promise for the use of DC as an effective second-line treatment. However, it is limited by conflicting trial results, a lack of trials, and a high risk of bias. Furthermore, most research comes from retrospective observational studies and case series. This narrative review considers the strength of evidence for the use of DC in both a high income country and low-and-middle income country setting and examine how we can improve study design to better assess the efficacy of this procedure and increase the clinical translatability of results to centers worldwide. Specifically, we argue for a need for further studies with higher pediatric participant numbers, multicenter collaboration, and the use of a more consistent methodology to enable comparability of results among settings.

Decompressive Craniectomy for Malignant Ischemic Stroke: An Institutional Experience of 145 Cases in a Brazilian Medical Center

BACKGROUND

Malignant ischemic stroke (MIS) occurs in a subgroup of patients with cerebrovascular accident who sustain massive or significant cerebral infarction. It is characterized by neurological deterioration owing to progressive edema, raised intracranial pressure, and cerebral herniation. Decompressive craniectomy (DC) is a surgical technique that can be used to treat select cases of this condition in the presence of medically refractory intracranial hypertension. This study aimed to identify prognostic factors associated with clinical outcome, including timing of the procedure, and postoperative mortality.

METHODS

We analyzed surgical characteristics associated with prognosis in 145 patients who underwent DC secondary to MIS between 2013 and 2018, assessing clinical outcome at discharge and 6 and 12 months after discharge. Our inclusion criteria were DC secondary to MIS in adult patients with raised intracranial pressure signs.

RESULTS

Our analysis showed that although patients from cities >100 km from the neurosurgical center had a worse prognosis, only the surgical head side (left vs. right, P = 0.001), hospitalization length (P < 0.001), and earlier timing of procedure (P < 0.001) were statistically relevant in having worse outcomes.

CONCLUSIONS

Patients in whom more time passed from presentation to the neurosurgical procedure, owing to living in a distant city or taking more time to be seen by a specialist, tended to have a worse prognosis. The timing of procedure, surgical side, and hospitalization length were independent predictors in determining the prognosis of patients who underwent DC after an MIS.

Decompressive craniectomy in traumatic brain injury: The intensivist's point of view

OBJETIVE

To perform a score with early clinical and radiological findings after a TBI that identifies the patients who in their subsequent evolution are going to undergo DC.

METHOD

Observational study of a retrospective cohort of patients who, after a TBI, enter the Neurocritical Section of the Intensive Care Unit of our hospital for a period of 5 years (2014-2018). Detection of clinical and radiological criteria and generation of all possible models with significant, clinically relevant and easy to detect early variables. Selection of the one with the lowest Bayesian Information Criterion and Akaike Information Criterion values for the creation of the score. Calibration and internal validation of the score using the Hosmer-Lemeshow and a bootstrapping analysis with 1000 re-samples respectively.

RESULTS

37 DC were performed in 153 patients who were admitted after a TBI. The resulting final model included Cerebral Midline Deviation, GCS and Ventricular Collapse with an Area under ROC Curve: 0.84 (95% IC 0.78-0.91) and Hosmer-Lemeshow p=0.71. The developed score detected well those patients who were going to need an early DC (first 24h) after a TBI (2.5±0.5) but not those who would need it in a later stage of their disease (1.7±0.8). However, it seems to advice us about the patients who, although not requiring an early DC are likely to need it later in their evolution (DC after 24h vs. do not require DC, 1.7±0.8 vs. 1±0.7; p=0.002).

CONCLUSION

We have developed a prognostic score using early clinical-radiological criteria that, in our environment, detects with good sensitivity and specificity those patients who, after a TBI, will require a DC.

Vacuum Drains versus Passive Drains versus No Drains in Decompressive Craniectomies-A Randomized Controlled Trial on Subgaleal Drain Complication Rates (VADER Trial)

OBJECTIVE

Subgaleal drains are generally deemed necessary for cranial surgeries including decompressive craniectomies (DCs) to avoid excessive postoperative subgaleal hematoma (SGH) formation. Many surgeries have moved away from routine prophylactic drainage but the role of subgaleal drainage in cranial surgeries has not been addressed.

METHODS

This was a randomized controlled trial at 2 centers. A total of 78 patients requiring DC were randomized in a 1:1:1 ratio into 3 groups: vacuum drains (VD), passive drains (PD), and no drains (ND). Complications studied were need for surgical revision, SGH amount, new remote hematomas, postcraniectomy hydrocephalus (PCH), functional outcomes, and mortality.

RESULTS

Only 1 VD patient required surgical revision to evacuate SGH. There was no difference in SGH thickness and volume among the 3 drain types (P = 0.171 and P = 0.320, respectively). Rate of new remote hematoma and PCH was not significantly different (P = 0.647 and P = 0.083, respectively), but the ND group did not have any patient with PCH. In the subgroup analysis of 49 patients with traumatic brain injury, the SGH amount of the PD and ND group was significantly higher than that of the VD group. However, these higher amounts did not translate as a significant risk factor for poor functional outcome or mortality. VD may have better functional outcome and mortality.

CONCLUSIONS

In terms of complication rates, VD, PD, and ND may be used safely in DC. A higher amount of SGH was not associated with poorer outcomes. Further studies are needed to clarify the advantage of VD regarding functional outcome and mortality, and if ND reduces PCH rates.

The Retroauricular Incision as an Effective and Safe Alternative Incision for Decompressive Hemicraniectomy

BACKGROUND

The reverse question mark (RQM) incision has been traditionally utilized to perform decompressive hemicraniectomies (DHC) to relieve refractory intracranial hypertension. Alternative incisions have been proposed in the literature but have not been compared directly.

OBJECTIVE

To present the retroauricular (RA) incision as an alternative incision that we hypothesize will increase calvarium exposure to maximize the removal of the hemicranium and will decrease wound-related complications compared to the RQM incision.

METHODS

This study is a retrospective review of all DHCs performed at our institution over a span of 34 mo, stratified based on the type of scalp incision. The surface areas of the cranial defects were calculated, normalizing to their respective skull diameters. For those patients surviving beyond 1 wk, complications were examined from both cohorts.

RESULTS

A total of 63 patients in the RQM group and 43 patients in the RA group were included. The average surface area for the RA and RQM incisions was 117.0 and 107.8 cm2 (P = .0009), respectively. The ratio of average defect size to skull size for RA incision was 0.81 compared to 0.77 for the RQM group (P = .0163). Of those who survived beyond 1 wk, the absolute risk for surgical site complications was 14.0% and 8.3% for RQM and RA group (P = .5201), respectively.

CONCLUSION

The RA incision provides a safe and effective alternative incision to the traditional RQM incision used for DHC. This incision affords a potentially larger craniectomy while mitigating postoperative wound complications.

Lifesaving Decompressive Craniectomy for High Intracranial Pressure Attributed to Deep-Seated Meningioma: Emergency Management

Objects:

As the most common intracranial extra-axial tumor among adults who tend to grow slowly with minimal clinical manifestation, the patients with meningioma could also fall in neurological emergency and even life-threatening status due to high intracranial pressure (ICP). In those circumstances, decompressive craniectomy (DC) without definitive tumor resection might offer an alternative treatment to alleviate acute increasing of ICP. The current report defines criteria for the indications of lifesaving DC for high ICP caused by deep-seated meningioma as an emergency management.

Patients and Methods:

This study collected the candidates from 2012 to 2018 at Dr. Soetomo General Hospital, Surabaya, Indonesia. The sample included all meningioma patients who came to our ER who fulfilled the clinical (life-threatening decrease in Glasgow Coma Scale [GCS]) and radiography (deep-seated meningioma, midline shift in brain computed tomography [CT] >0.5 cm, and diameter of tumor >4 cm or tumor that involves the temporal lobe) criteria for emergency DC as a lifesaving procedure. GCS, midline shift, tumor diameter, and volume based on CT were evaluated before DC. Immediate postoperative GCS, time to tumor resection, and Glasgow Outcome Scale (GOS) were also assessed postoperation.

Results:

The study enrolled 14 patients, with an average preoperative GCS being 9.29 ± 1.38, whereas the mean midline shift was 15.84 ± 7.02 mm. The average of number of tumor's diameter and volume was 5.59 ± 1.44 cm and 66.76 ± 49.44 cc, respectively. Postoperation, the average time interval between DC and definitive tumor resection surgery was 5.07 ± 3.12 days. The average immediate of GCS postoperation was 10.07 ± 2.97, and the average GOS was 3.93 ± 1.27.

Conclusion:

When emergency tumor resection could not be performed due to some limitation, as in developing countries, DC without tumor resection possibly offers lifesaving procedure in order to alleviate acute increasing ICP before the definitive surgical procedure is carried out. DC might also prevent a higher risk of morbidity and postoperative complications caused by peritumoral brain edema.

Clinical Efficacy and Safety of Silicone Elastomer Sheet during Decompressive Craniectomy: Anti-Adhesive Role in Cranioplasty

(1) Background: Cranioplasty is a surgery to repair a skull bone defect after decompressive craniectomy (DC). If the process of dissection of the epidural adhesion tissue is not performed properly, it can cause many complications. We reviewed the effect of a silicone elastomer sheet designed to prevent adhesion. (2) Methods: We retrospectively reviewed 81 consecutive patients who underwent DC and subsequent cranioplasty at our institution between January 2015 and December 2019. We then divided the patients into two groups, one not using the silicone elastomer sheet (n = 50) and the other using the silicone elastomer sheet (n = 31), and compared the surgical outcomes. (3) Results: We found that the use of the sheet shortened the operation time by 24% and reduced the estimated blood loss (EBL) by 43% compared to the control group. Moreover, the complication rate of epidural fluid collection (EFC) in the group using the sheet was 16.7%, which was lower than that in the control group (41.7%, p < 0.023). Multivariate logistic regression analysis showed the sheet (OR 0.294, 95% CI 0.093–0.934, p = 0.039) to be significantly related to EFC. (4) Conclusions: The technique using the silicone elastomer sheet allows surgeons to easily dissect the surgical plane during cranioplasty, which shortens the operation time, reduces EBL, and minimizes complications of EFC.

Decompressive craniectomy in traumatic brain injury: the intensivist's point of view

OBJETIVE

To perform a score with early clinical and radiological findings after a TBI that identifies the patients who in their subsequent evolution are going to undergo DC.

METHOD

Observational study of a retrospective cohort of patients who, after a TBI, enter the Neurocritical Section of the Intensive Care Unit of our hospital for a period of 5 years (2014-2018). Detection of clinical and radiological criteria and generation of all possible models with significant, clinically relevant and easy to detect early variables. Selection of the one with the lowest Bayesian Information Criterion and Akaike Information Criterion values for the creation of the score. Calibration and internal validation of the score using the Hosmer-Lemeshow and a bootstrapping analysis with 1,000 re-samples respectively.

RESULTS

37 DC were performed in 153 patients who were admitted after a TBI. The resulting final model included Cerebral Midline Deviation, GCS and Ventricular Collapse with an Area under ROC Curve: 0.84 (95% IC 0.78-0.91) and Hosmer-Lemeshow p=0.71. The developed score detected well those patients who were going to need an early DC (first 24hours) after a TBI (2.5±0.5) but not those who would need it in a later stage of their disease (1.7±0.8). However, it seems to advice us about the patients who, although not requiring an early DC are likely to need it later in their evolution (DC after 24hours vs do not require DC, 1.7±0.8 vs 1±0.7; p=0.002).

CONCLUSION

We have developed a prognostic score using early clinical-radiological criteria that, in our environment, detects with good sensitivity and specificity those patients who, after a TBI, will require a DC.

Long-Term Effect of Decompressive Craniectomy on Intracranial Pressure and Possible Implications for Intracranial Fluid Movements

BACKGROUND

Decompressive craniectomy (DC) is used in cases of severe intracranial hypertension or impending intracranial herniation. DC effectively lowers intracranial pressure (ICP) but carries a risk of severe complications related to abnormal ICP and/or cerebrospinal fluid (CSF) circulation, eg, hygroma formation, hydrocephalus, and "syndrome of the trephined."

OBJECTIVE

To study the long-term effect of DC on ICP, postural ICP regulation, and intracranial pulse wave amplitude (PWA).

METHODS

Prospective observational study including patients undergoing DC during a 12-mo period. Telemetric ICP sensors (Neurovent-P-tel; Raumedic, Helmbrechts, Germany) were implanted in all patients. Following discharge from the neuro intensive care unit (NICU), scheduled weekly ICP monitoring sessions were performed during the rehabilitation phase.

RESULTS

A total of 16 patients (traumatic brain injury: 7, stroke: 9) were included (median age: 55 yr, range: 19-71 yr). Median time from NICU discharge to cranioplasty was 48 d (range: 16-98 d) and during this period, mean ICP gradually decreased from 7.8 ± 2.0 mm Hg to -1.8 ± 3.3 mm Hg (P = .02). The most pronounced decrease occurred during the first month. Normal postural ICP change was abolished after DC for the entire follow-up period, ie, there was no difference between ICP in supine and sitting position (P = .67). PWA was markedly reduced and decreased from initially 1.2 ± 0.7 mm Hg to 0.4 ± 0.3 mm Hg (P = .05).

CONCLUSION

Following NICU discharge, ICP decreases to negative values within 4 wk, normal postural ICP regulation is lost and intracranial PWA is diminished significantly. These abnormalities might have implications for intracranial fluid movements (eg, CSF and/or glymphatic flow) following DC and warrants further investigations.

Aggressive internal and external decompression as a life-saving surgery in a deeply comatose patient with fixed dilated pupils after severe traumatic brain injury: A case report

Background:

To maximize control of the intracranial pressure in deeply comatose patients with malignant cerebral swelling, combination of the surgical techniques for internal and external brain decompression may be reasonable, as demonstrated in the presented case.

Case Description:

A 55-year-old man was admitted with Glasgow Coma Scale (GCS) score 4, maximally dilated pupils, and absence of the pupillary light and vestibulo-ocular reflexes. Head CT revealed massive acute subdural hematoma, prominent brain shift with subfalcine and transtentorial herniation, and diffuse subarachnoid hemorrhage. Large size decompressive craniectomy and evacuation of subdural hematoma were done, however, prominent swelling of the brain and its protrusion through the bone defect remained. Therefore, extensive temporal lobectomy and removal of the bulk of temporal muscle were additionally attained followed by lax duraplasty. Gradual recovery of the patient was noted from the 1^st postoperative day, and on the 70^th day, his GCS score was 4T4. Three months later, his condition corresponded to the Glasgow Outcome Scale score 3 (severe disability).

Conclusion:

Aggressive internal and external decompression with combination of large size craniectomy, extensive temporal lobectomy, removal of the bulk of temporal muscle, and lax duraplasty should be considered as possible life-saving option in cases of neurosurgical emergencies with malignant cerebral swelling.

Transcalvarial brain herniation volume as a predictor of posttraumatic hydrocephalus after decompressive craniectomy

OBJECTIVES

In patients undergoing decompressive craniectomy for traumatic brain injury(TBI) there has been reported an incidence of hydrocephalus between 0-45%. There are several radiological and clinical features described in association with development of hydrocephalus. For study the influence of these factors we conducted a retrospective observational single-center cohort study in a tertiary care center with special attention to the transcalvarial herniation(TCH) volume after decompressive craniectomy.

PATIENTS AND METHODS

We selected 50 patients that underwent decompressive craniectomy after closed head injury between january 2014 and January 2015. Hydrocephalus was defined as a modified frontal horn index greater than 33%, presence of Gudeman CT scan criteria or insertion of ventriculoperitoneal Shunt. Variables analyzed were: age, post-resuscitation Glasgow coma scale (GCS) score, pupil reactivity, Zunkeller index, presence of hygroma, TCH volume, craniectomy diameter and distance of craniectomy from midline. Logistic regression was used with hydrocephalus as the primary outcome measure.

RESULTS

17 patients developed hydrocephalus (34%). TCH volume after decompression(p < 0.01), subdural hygroma (p < 0.01), lower admission Glasgow Coma Scale score (p = 0.015), unilateral pupil reactivity(p = 0.042) and higher Zumkeller index(p = 0.044) were significant risk factors for hydrocephalus. Logistic regression analysis showed that factors independently associated with the development of hydrocephalus was the TCH volume (odds ratio 11.08; 95%CI 2.10, 58.4; p = 0.0046), and presence of hygroma (odds ratio 49.59; 95%IC 4.1, 459; p = 0.002).

CONCLUSIONS

There was a clear association between severity of TBI, TCH volume and subdural hygroma with the development of hydrocephalus. Clinicians should follow closely patients with those findings in order to avoid late deterioration.

Relationship between Clinical Outcomes and Superior Sagittal Sinus to Bone Flap Distance during Unilateral Decompressive Craniectomy in Patients with Traumatic Brain Injury: Experience at a Single Trauma Center

Objective

This retrospective study was conducted to investigate the relationship between the superior sagittal sinus (SSS) to bone flap distance and clinical outcome in patients with traumatic brain injury (TBI) who underwent decompressive craniectomy (DC).

Methods

A retrospective review of medical records identified 255 adult patients who underwent DC with hematoma removal to treat TBI at our hospital from 2016 through 2017; of these, 68 patients met the inclusion criteria and underwent unilateral DC. The nearest SSS to bone flap distances were measured on postoperative brain computed tomography images, and patients were divided into groups A (distance ≥20 mm) and B (distance <20 mm). The estimated blood loss (EBL) and operation time were evaluated using anesthesia records, and the time spent in an intensive care unit (ICU) was obtained by chart review. The clinical outcome was rated using the extended Glasgow Outcome Scale (GOS-E) at 3 and 6 months postoperatively.

Results

The male to female ratio was 15:2 and the mean subject age was 55.12 years (range, 18–79 years). The mean EBL and operation times were significantly different between groups A and B (EBL: 655.26 vs. 1803.33 mL, p<0.001; operation time: 125.92 vs. 144.83 min, p<0.001). The time spent in the ICU and GOS-E scores did not differ significantly between the groups.

Conclusion

We recommend that when DC is indicated due to TBI, an SSS to bone flap distance of at least 20 mm should be maintained, considering the EBL, operation time, and other outcomes.

Rationale Behind the Use of Double-Layer Polypropylene Patch (G-patch) Dural Substitute During Decompressive Craniectomy as an Adhesion Preventive Material for Subsequent Cranioplasty with Special Reference to Flap Elevation Time

OBJECTIVE

Dural substitutes are used in decompressive craniectomy (DC) to prevent adhesions during subsequent cranioplasty. Current literature attributes them to reduced blood loss and reduction in operative time of cranioplasty. The use of double-layer substitute has rarely been documented. We studied the use of double-layer G-patch as a dural substitute in DC and evaluated its outcome during subsequent cranioplasty with special focus on flap elevation time and blood loss during cranioplasty.

METHODS

We performed emergency frontotemporoparietal decompressive craniectomy using a double layer of G-patch as dural substitute. Subsequent cranioplasty was done in these 35 patients. The development of adhesion formation between the tissue layers, amount of blood loss, and flap elevation time were recorded.

RESULTS

During the cranioplasty, a clear and smooth plane of dissection was found between the 2 layers of G-patch in all cases. Average flap elevation time was 21.8 minutes, and average time taken for cranioplasty was 124.12 minutes. Average blood loss was 83 mL. None of the patients required re-exploration for infection of bone flap or postoperative bleed.

CONCLUSIONS

While evaluating the use of dural substitute during DC as an adhesion preventive material for subsequent cranioplasty, flap elevation time and blood loss should be taken into account rather than operative time. Double-layer G-patch during DC facilitates subsequent cranioplasty by preventing adhesions between the layers, resulting in easier dissection and reduced blood loss.

Bulging brains

Brain swelling is a serious condition associated with an accumulation of fluid inside the brain that can be caused by trauma, stroke, infection, or tumors. It increases the pressure inside the skull and reduces blood and oxygen supply. To relieve the intracranial pressure, neurosurgeons remove part of the skull and allow the swollen brain to bulge outward, a procedure known as decompressive craniectomy. Decompressive craniectomy has been preformed for more than a century; yet, its effects on the swollen brain remain poorly understood. Here we characterize the deformation, strain, and stretch in bulging brains using the nonlinear field theories of mechanics. Our study shows that even small swelling volumes of 28 to 56 ml induce maximum principal strains in excess of 30%. For radially outward-pointing axons, we observe maximal normal stretches of 1.3 deep inside the bulge and maximal tangential stretches of 1.3 around the craniectomy edge. While the stretch magnitude varies with opening site and swelling region, our study suggests that the locations of maximum stretch are universally shared amongst all bulging brains. Our model has the potential to inform neurosurgeons and rationalize the shape and position of the skull opening, with the ultimate goal to reduce brain damage and improve the structural and functional outcomes of decompressive craniectomy in trauma patients.

Decompressive Craniectomy in Traumatic Brain Injury: A Review Article

The importance of treating traumatic brain injury (TBI) is well known worldwide. Although many studies have been conducted in this topic, there is still much uncertainty about the effectiveness of surgical treatment in TBI. Recently, good randomized controlled trial (RCT) papers about the effectiveness of decompressive craniectomy (DC) in TBI has been published. In this article, we will review the overall contents of the DC (historical base, surgical technic, rationale, complications) and the results of the recently published RCT paper.

Decompressive craniectomy in acute brain injury

Decompressive surgery to reduce pressure under the skull varies from a burrhole, bone flap to removal of a large skull segment. Decompressive craniectomy is the removal of a large enough segment of skull to reduce refractory intracranial pressure and to maintain cerebral compliance for the purpose of preventing neurologic deterioration. Decompressive hemicraniectomy and bifrontal craniectomy are the most commonly performed procedures. Bifrontal craniectomy is most often utilized with generalized cerebral edema in the absence of a focal mass lesion and when there are bilateral frontal contusions. Decompressive hemicraniectomy is most commonly considered for malignant middle cerebral artery infarcts. The ethical predicament of deciding to go ahead with a major neurosurgical procedure with the purpose of avoiding brain death from displacement, but resulting in prolonged severe disability in many, are addressed. This chapter describes indications, surgical techniques, and complications. It reviews results of recent clinical trials and provides a reasonable assessment for practice.

Modelling of Brain Deformation After Decompressive Craniectomy

Hyperelastic finite element models, with either an idealized cylindrical geometry or with realistic craniectomy geometries, were used to explore clinical issues relating to decompressive craniectomy. The potential damage in the brain tissue was estimated by calculating the volume of material exceeding a critical shear strain. Results from the idealized model showed how the potentially damaged volume of brain tissue increased with an increasing volume of brain tissue herniating from the skull cavity and with a reduction in craniectomy area. For a given herniated volume, there was a critical craniectomy diameter where the volume exceeding a critical shear strain fell to zero. The effects of details at the craniectomy edge, specifically a fillet radius and a chamfer on the bone margin, were found to be relatively slight, assuming that the dura is retained to provide effective protection. The location in the brain associated with volume expansion and details of the material modeling were found to have a relatively modest effect on the predicted damage volume. The volume of highly sheared material in the realistic models of the craniectomy varied roughly in line with differences in the craniectomy area.

Predictive factors for decompressive hemicraniectomy in malignant middle cerebral artery infarction

BACKGROUND

The mortality rate of patients with brain oedema after malignant middle cerebral artery (MCA) infarction approaches 80 % without surgical intervention. Surgical treatment with ipsilateral decompressive hemicraniectomy (DHC) has been shown to dramatically improve survival rates. DHC currently lacks established inclusion criteria and additional research is needed to assess the impact of prognostic factors on functional outcome. The aim of this study was to assess the impact of prognostic factors on functional outcome.

METHOD

A retrospective cohort study was carried out including 46 patients who underwent DHC at the Karolinska University Hospital between 2004 and 2014. The maximum time to surgery was 5 days after symptom debut. The primary endpoint was a dichotomised score on the modified Rankin Scale (mRS) 3 months after surgery, with favourable outcome defined as mRS ≤ 4.

RESULTS

When the study population was dichotomised according to the primary endpoint, a significant difference between the groups was seen in preoperative Glasgow Coma Score (GCS), blood glucose levels and the infarction's involvement of the basal ganglia (p < 0.05). In a logistic regression model, preoperative GCS contributed significantly with a 59.6 % increase in the probability of favourable outcome for each point gained in preoperative GCS (p = 0.035).

CONCLUSIONS

The results indicate that preoperative GCS, blood glucose and the infarction's involvement of the basal ganglia are strong predictors of clinical outcome. These factors should be considered when assessing the probable outcome of DHC, and additional research based on these factors may contribute to improved inclusion criteria for DHC.

Decompression surgery for severe traumatic brain injury (TBI): A long-term, single-centre experience

INTRODUCTION

Despite well-conducted medical treatment, refractory intracranial hypertension occurs in 10-15% of patients with severe traumatic brain injury (TBI). Surgical decompression procedures, such as hemicraniectomy, are mainly considered as a rescue therapy. However, the long-term neurological outcomes of these patients remain controversial. Thus, the purpose of this study was to investigate the long-term evolution of patients requiring surgical decompression surgery in our ICU over the last 7 years.

METHODS

We conducted a retrospective single-centre study over the last 7 years. Severe traumatic brain injury patients presenting a refractory intracranial hypertension (ICP) and who underwent decompression surgery were included. Demographic data, in-hospital complications (infectious diseases, seizures) and in-hospital mortality were studied. Patients were further (from 1 to 8 years post injury) contacted for questioning including evaluation of the Glasgow Outcome Scale (GOS), recovery of professional activity, concentration disorders, motor and mood disabilities, sleep disorders, headaches, or seizure occurrences. We compared this population with patients presenting elevated ICP not needing surgery, and matched on gender, age, SAPS II scores, initial GCS, and time since TBI.

RESULTS

Twenty patients required decompression surgery during the studied period (2%), half of whom deceased during that time. Among surviving patients, 22% had seizures. Memory disorders represented the most frequently reported disability (100% of questioned patients). Half of the patients presented sleep disorders and headaches after hospitalization. Only 33% of these patients recovered a professional activity after treatment. Compared to the matched population, long-term neurological status was equivalent in survivors.

CONCLUSION

In this small retrospective study, we found that decompression surgery performed for traumatic refractory raised ICP concerned only 2% of our traumatic brain injury patients. According to long-term evaluation, decompression surgery is associated with unfavourable outcomes and disabilities. However, the functional recovery and quality of life in survivors seems equivalent to a matched population. These results require confirmation via larger studies.

A new improved method for assessing brain deformation after decompressive craniectomy

Background

Decompressive craniectomy (DC) is a surgical intervention used following traumatic brain injury to prevent or alleviate raised intracranial pressure. However the clinical effectiveness of the intervention remains in doubt. The location of the craniectomy (unilateral or bifrontal) might be expected to change the brain deformation associated with the operation and hence the clinical outcome. As existing methods for assessing brain deformation have several limitations, we sought to develop and validate a new improved method.

Methods

Computed tomography (CT) scans were taken from 27 patients who underwent DC (17 bifrontal patients and 10 unilateral patients). Pre-operative and post-operative images were processed and registered to determine the change in brain position associated with the operation. The maximum deformation in the herniated brain, the change in volume and estimates of the craniectomy area were determined from the images. Statistical comparison was made using the Pearson’s correlation coefficient r and a Welch’s two-tailed T-test, with statistical significance reported at the 5% level.

Results

There was a reasonable correlation between the volume increase and the maximum brain displacement (r = 0.64), a low correlation between the volume increase and the craniectomy area (r = 0.30) and no correlation between the maximum displacement and the craniectomy area (r = −0.01). The maximum deformation was significantly lower (P  = 0.023) in the bifrontal patients (mean = 22.5 mm) compared with the unilateral patients (mean = 29.8 mm). Herniation volume was significantly lower (P = 0.023) in bifrontal (mean = 50.0 ml) than unilateral patients (mean = 107.3 ml). Craniectomy area was not significantly different for the two craniectomy locations (P = 0.29).

Conclusions

A method has been developed to quantify changes in brain deformation due to decompressive craniectomy from CT images and allow comparison between different craniectomy locations. Measured displacement is a reasonable way to characterise volume changes.

Surgical treatment of elevated intracranial pressure: decompressive craniectomy and intracranial pressure monitoring

Surgical techniques that address elevated intracranial pressure include (1) intraventricular catheter insertion and cerebrospinal fluid drainage, (2) removal of an intracranial space-occupying lesion, and (3) decompressive craniectomy. This review discusses the role of surgery in the management of elevated intracranial pressure, with special focus on intraventricular catheter placement and decompressive craniectomy. The techniques and potential complications of each procedure are described, and the existing evidence regarding the impact of these procedures on patient outcome is reviewed. Surgical management of mass lesions and ischemic or hemorrhagic stroke occurring in the posterior fossa is not discussed herein.

Decompressive craniectomy using gelatin film and future bone flap replacement

Object

Decompressive craniectomy plays an important role in the management of patients with traumatic brain injury (TBI) and stroke. Risks of decompressive craniectomy include those associated with cranioplasty, and may be related to adhesions that develop between the brain surface and overlying scalp and temporalis muscle. The authors report their institutional experience using a multilayered technique (collagen and gelatin film barriers) to facilitate safe and rapid cranioplasty following decompressive craniectomy.

Methods

The authors conducted a retrospective chart review of 62 consecutive adult and pediatric patients who underwent decompressive craniectomy and subsequent cranioplasty between December 2007 and January 2011. Diagnoses included TBI, ischemic stroke, intraparenchymal hemorrhage, or subarachnoid hemorrhage. A detailed review of clinical charts was performed, including anesthesia records and radiographic study results.

Results

The majority of patients underwent unilateral hemicraniectomy (n = 56), with indications for surgery including midline shift (n = 37) or elevated intracranial pressure (n = 25). Multilayered decompressive craniectomy was safe and easy to perform, and was associated with a low complication rate, minimal operative time, and limited blood loss.

Conclusions

Decompressive craniectomy repair using an absorbable gelatin film barrier facilitates subsequent cranioplasty by preventing adhesions between intracranial contents and the overlying galea aponeurotica and temporalis muscle fascia. This technique makes cranioplasty dissection faster and potentially safer, which may improve clinical outcomes. The indications for gelatin film should be expanded to include placement in the epidural space after craniectomy.

Decompressive craniectomy with massive intractable intraoperative cerebral edema: utilization of silicone sheet for temporary scalp closure

The authors present a case of extreme brain herniation encountered during decompressive craniectomy in a 21-month-old boy who suffered a trauma event that necessitated temporary scalp closure in which a sterile silicone sheet was placed. Although the clinical situation is usually expected to lead to brain death or severe disability, the patient's 3-year follow-up examination revealed a highly functional child with a good quality of life. The authors discuss the feasibility and advantages of temporary scalp expansion as a treatment option when extreme brain herniation is encountered during craniotomy.

Decompressive craniectomy - operative technique and perioperative care

With improvements in neurocritical care advanced measures of treating raised intracranial pressure (ICP) are more frequently utilised. Decompressive craniectomy is an effective ICP-lowering procedure; however its benefits are maximised with optimal surgical technique and perioperative care, as well as by paying attention to possible complications. This article focuses on the current indications and rationale for decompressive craniectomy, and the surgical technique of bifrontal and unilateral decompression. The key surgical points include a large craniectomy window and opening of the dura, leaving it unsutured or performing a wide non-constricting duroplasty. Perioperative care and possible complications are also discussed.