The current role of decompressive craniectomy in the management of neurological emergencies

Efficacy of decompressive craniectomy: A retrospective case series study with 321 patients and an update on controversies

Decompressive craniectomy (DC) is considered a cornerstone in the management of refractory intracranial hypertension. For decades, DC was known as an occasionally lifesaving procedure; however, it was associated with numerous severe complications. The present study is a single-center retrospective case series study on with 321 patients who underwent DC between January, 2010 and December, 2020. All patients were divided into four groups as follows: Group A included patients who suffered from a space-occupying middle cerebral artery (MCA) ischemic event; group B included individuals who developed intracerebral hemorrhage; group C included patients admitted for traumatic brain injury; and group D included patients with other neurosurgical entities that underwent DC, such as subarachnoid hemorrhage, tumors, brain abscess and cerebral ventricular sinus thrombosis events. The present study enrolled a total of 321 patients who underwent DC. Group A included 52 out of the 321 (16.1%) patients, group B included 51 (15.8%) patients, group C included 164 (51.0%) patients, and group D included 54 (16.8%) patients. Of the 321 patients, 235 (73.2%) were males, and the median age was 53.7 years. Multivariate analysis revealed that only the group A parameter was an independent factor associated with a Glasgow outcome scale score >2 during follow-up (P<0.05). On the whole, the results of the present study suggest that among patients who underwent DC with different neurological entities, those who had experienced MCA events had more favorable outcomes.

Craniotomy versus Decompressive Craniectomy in Acute Subdural Hematoma Management: A Systematic Review and Meta-Analysis

BACKGROUND

 This study aimed to compare the clinical outcomes of decompressive craniectomy (DC) and craniotomy in treating acute subdural hematoma (ASDH) to provide a more precise assessment of the procedures' outcomes.

METHODS

 We searched for relevant articles in PubMed, Web of Science, Embase, Scopus, and Cochrane till August 2023, including cohort studies and randomized controlled trials comparing craniotomy and DC for ASDH. The analysis was conducted using "Review Manager" software, using the risk ratio along with a 95% confidence interval (CI) for categorical data, whereas continuous data were analyzed using the mean difference (MD) and 95% CI.

RESULTS

 Our analysis included 13 studies with a total of 4,689 patients, of whom 1,910 (40.7%) underwent DC and 2,779 (59.3%) underwent craniotomy. The results revealed a statistically significant difference in favor of craniotomy concerning good recovery in delayed GOS (risk ratio [RR] = 1.42; 95% CI [1.12, 1.81]), postoperative mortality (RR = 0.81; 95% CI [0.71, 0.94]), mortality at last follow-up (RR = 0.75; 95% CI [0.62, 0.91]), and hospital stay (MD = -3.71; 95%CI [-5.82, -1.60]). A nonsignificant difference (RR = 1.06; 95% CI [0.52, 2.17]; p = 0.87) was found between the two interventions concerning seizures.

CONCLUSION

 Despite craniotomy's favorable clinical outcomes and mortality rates, the significant baseline differences between DC and craniotomy make these data inconclusive. To establish solid evidence regarding the use of DC versus craniotomy in ASDH, it is necessary to conduct well-controlled randomized studies with large sample sizes.

Comparison of Craniotomy Versus Decompressive Craniectomy for Acute Subdural Hematoma: A Systematic Review and Meta-Analysis

OBJECTIVE

Acute subdural hematoma (ASDH) is a common critical neurosurgical condition, often requiring immediate surgical intervention. Craniotomy and decompressive craniectomy are the 2 mainstay surgical approaches. This comprehensive review and meta-analysis aims to summarize the existing evidence and compare the outcomes of these 2 procedures.

METHODS

PubMed, Embase, Cochrane Central Register of Controlled Trials, and CINAHL electronic databases were searched for relevant studies, published between inception of databases till June 2023. Eligible studies reported data of patients diagnosed with ASDH who underwent craniotomy or decompressive craniectomy for ASDH. Outcome measures included the Glasgow Coma Scale score, residual subdural hematoma, requirement of revision surgery, poorer outcomes, and mortality. Data were presented as pooled odds ratios with 95% confidence intervals. Quality assessment and risk of bias were performed for each study.

RESULTS

Fourteen studies with a total of 3095 patients were included. The results showed that patients who underwent craniotomy had significantly lower mortality, lower odds of poorer outcomes, and a higher rate of residual subdural hematoma, compared to patients who underwent decompressive craniectomy. There was no significant difference in the requirement of revision surgery between the 2 groups. Heterogeneity was high for most outcomes, and the quality of evidence ranged from moderate to low.

CONCLUSION

Our findings suggest that craniotomy is associated with better clinical outcomes and lower mortality compared to decompressive craniectomy for ASDH, but a higher rate of residual subdural hematoma. Further high-quality randomized controlled trials are needed to validate our findings.

Improved rehabilitation efficiency after cranioplasty in patients with sunken skin flap syndrome: a case series

PURPOSE

Sunken Skin Flap Syndrome (SSFS) is an uncommon, delayed complication after craniectomy characterized by a functional plateau or decline with variable neurologic symptoms, improving after cranioplasty. SSFS negatively impacts the rehabilitation course, with subjective reports of functional improvement after cranioplasty. However, no studies have assessed the impact of cranioplasty on functional recovery rate. This case series aims to analyze SSFS manifestations and management while awaiting cranioplasty. Also, to assess the role of cranioplasty on rehabilitation outcomes and recovery rate in SSFS patients.

METHODS

Four patients were identified with SSFS in inpatient rehabilitation. Each patient had unique clinical manifestations, with multiple strategies used for symptomatic control. Patients spent an average of 23 days in rehabilitation with SSFS symptoms before cranioplasty. After cranioplasty, all patients had SSFS symptom resolution. Comparing change in functional independence measure (FIM) scores and FIM efficiency pre-and post-cranioplasty rehabilitation course, a mean improvement of 23 and 0.72 occurred after cranioplasty, respectively.

CONCLUSION

A diagnosis of SSFS should be considered in craniectomy patients exhibiting functional decline or plateau with associated neurological symptoms. This study suggests that FIM and FIM efficiency increases in SSFS patients after cranioplasty, supporting prompt cranioplasty to improve functional outcomes and minimize rehabilitation delays.

Complications and cosmetic outcomes of materials used in cranioplasty following decompressive craniectomy-a systematic review, pairwise meta-analysis, and network meta-analysis

BACKGROUND

Optimal reconstruction materials for cranioplasty following decompressive craniectomy (DC) remain unclear. This systematic review, pairwise meta-analysis, and network meta-analysis compares cosmetic outcomes and complications of autologous bone grafts and alloplasts used for cranioplasty following DC.

METHOD

PubMed, Embase, and Cochrane were searched from inception until April 2021. A random-effects pairwise meta-analysis was used to compare pooled outcomes and 95% confidence intervals (CIs) of autologous bone to combined alloplasts. A frequentist network meta-analysis was subsequently conducted to compare multiple individual materials.

RESULTS

Of 2033 articles screened, 30 studies were included, consisting of 29 observational studies and one randomized control trial. Overall complications were statistically significantly higher for autologous bone compared to combined alloplasts (RR = 1.56, 95%CI = 1.14-2.13), hydroxyapatite (RR = 2.60, 95%CI = 1.17-5.78), polymethylmethacrylate (RR = 1.50 95%CI = 1.08-2.08), and titanium (Ti) (RR = 1.56 95%CI = 1.03-2.37). Resorption occurred only in autologous bone (15.1%) and not in alloplasts (0.0%). When resorption was not considered, there was no difference in overall complications between autologous bone and combined alloplasts (RR = 1.00, 95%CI = 0.75-1.34), nor between any individual materials. Dehiscence was lower for autologous bone compared to combined alloplasts (RR = 0.39, 95%CI = 0.19-0.79) and Ti (RR = 0.34, 95%CI = 0.15-0.76). There was no difference between autologous bone and combined alloplasts with respect to infection (RR = 0.85, 95%CI = 0.56-1.30), migration (RR = 1.36, 95%CI = 0.63-2.93), hematoma (RR = 0.98, 95%CI = 0.53-1.79), seizures (RR = 0.83, 95%CI = 0.29-2.35), satisfactory cosmesis (RR = 0.88, 95%CI = 0.71-1.08), and reoperation (RR = 1.66, 95%CI = 0.90-3.08).

CONCLUSIONS

Bone resorption is only a consideration in autologous cranioplasty compared to bone substitutes explaining higher complications for autologous bone. Dehiscence is higher in alloplasts, particularly in Ti, compared to autologous bone.

Evaluation of the Fitting Accuracy of CAD/CAM-Manufactured Patient-Specific Implants for the Reconstruction of Cranial Defects-A Retrospective Study

Cranioplasties show overall high complication rates of up to 45.3%. Risk factors potentially associated with the occurrence of postoperative complications are frequently discussed in existing research. The present study examines the positioning of 39 patient-specific implants (PSI) made from polyetheretherketone (PEEK) and retrospectively investigates the relationship between the fitting accuracy and incidence of postoperative complications. To analyze the fitting accuracy of the implants pre- and post-operatively, STL files were created and superimposed in a 3D coordinate system, and the deviations were graphically displayed and evaluated along with the postoperative complications. On average, 95.17% (SD = 9.42) of the measurements between planned and surgically achieved implant position were within the defined tolerance range. In cases with lower accordance, an increased occurrence of complications could not be demonstrated. The overall postoperative complication rate was 64.1%. The fitting of the PEEK-PSI was highly satisfactory. There were predominantly minor deviations of the achieved compared to the planned implant positions; however, estimations were within the defined tolerance range. Despite the overall high accuracy of fitting, a considerable complication rate was found. To optimize the surgical outcome, the focus should instead be directed towards the investigation of other risk factors.

The effect of hematoma puncture drainage before decompressive craniectomy on the prognosis of hypertensive intracerebral hemorrhage with cerebral hernia at a high altitude

PURPOSE

Rapid decompressive craniectomy (DC) was the most effective method for the treatment of hypertensive intracerebral hemorrhage (HICH) with cerebral hernia, but the mortality and disability rate is still high. We suspected that hematoma puncture drainage (PD) + DC may improve the therapeutic effect and thus compared the combined surgery with DC alone.

METHODS

From December 2013 to July 2019, patients with HICH from Linzhi, Tibet and Honghe, Yunnan Province were retrospectively analyzed. The selection criteria were as follows: (1) altitude ≥1500 m; (2) HICH patients with cerebral hernia; (3) Glascow coma scale score of 4-8 and time from onset to admission ≤3 h; (4) good liver and kidney function; and (5) complete case data. The included patients were divided into DC group and PD + DC group. The patients were followed up for 6 months. The outcome was assessed by Glasgow outcome scale (GOS) score, Kaplan-Meier survival curve and correlation between time from admission to operation and prognosis. A good outcome was defined as independent (GOS score, 4-5) and poor outcome defined as dependent (GOS score, 3-1). All data analyses were performed using SPSS 19, and comparison between two groups was conducted using separate t-tests or Chi-square tests.

RESULTS

A total of 65 patients was included. The age ranged 34-90 years (mean, 63.00 ± 14.04 years). Among them, 31 patients had the operation of PD + DC, whereas 34 patients underwent DC. The two groups had no significant difference in the basic characteristics. After 6 months of follow-up, in the PD + DC group there were 8 death, 4 vegetative state, 4 severe disability (GOS score 1-3, poor outcome 51.6 %); 8 moderate disability, and 7 good recovery (GOS score 4-5, good outcome 48.4 %); while in the DC group the result was 15 death, 6 vegetative state, 5 severe disability (poor outcome 76.5 %), 4 moderate disability and 4 good recovery (good outcome 23.5 %). The GOS score and good outcome were significantly less in DC group than in PD + DC group (Z = -1.993, p = 0.046; χ² = 4.38, p = 0.043). However, there was no significant difference regarding the survival curve between PD + DC group and DC group. The correlation between the time from admission to operation and GOS at 6 months (r = -0.41, R² = 0.002, p = 0.829) was not significant in the PD + DC group, but significant in the DC group (r = -0.357, R² = 0.128, p = 0.038).

CONCLUSION

PD + DC treatment can improve the good outcomes better than DC treatment for HICH with cerebral hernia at a high altitude.

Clinical Significance of Decompressive Craniectomy Surface Area and Side

Objective

Decompressive craniectomy (DC) can partially remove the unyielding skull vault and make affordable space for the expansion of swelling brain contents. The objective of this study was to compare clinical outcome according to DC surface area (DC area) and side.

Methods

A total of 324 patients underwent different surgical methods (unilateral DC, 212 cases and bilateral DC, 112 cases) were included in this retrospective analysis. Their mean age was 53.4±16.6 years (median, 54 years). Neurological outcome (Glasgow outcome scale), ventricular intracranial pressure (ICP), and midline shift change (preoperative minus postoperative) were compared according to surgical methods and total DC area, DC surface removal rate (DC%) and side.

Results

DC surgery was effective for ICP decrease (32.3±16.7 mmHg vs. 19.2±13.4 mmHg, p<0.001) and midline shift change (12.5±7.6 mm vs. 7.8±6.9 mm, p<0.001). The bilateral DC group showed larger total DC area (125.1±27.8 cm² for unilateral vs. 198.2±43.0 cm² for bilateral, p<0.001). Clinical outcomes were nonsignificant according to surgical side (favorable outcome, p=0.173 and mortality, p=0.470), significantly better when total DC area was over 160 cm² and DC% was 46% (p=0.020 and p=0.037, respectively).

Conclusion

DC surgery is effective in decrease the elevated ICP, decrease the midline shift and improve the clinical outcome in massive brain swelling patient. Total DC area and removal rate was larger in bilateral DC than unilateral DC but clinical outcome was not influenced by DC side. DC area more than 160 cm² and DC surface removal rate more than 46% were more important than DC side.

Long-term follow-up of patients undergoing decompressive hemicraniectomy for malignant stroke: Quality of life and caregiver's burden in a real-world setting

BACKGROUND AND PURPOSE

Decompressive hemicraniectomy is a life-saving procedure for the treatment of space-occupying middle cerebral artery infarctions (malignant stroke); however, patients may survive severely disabled. Comprehensive data on long-term sequelae outside randomized controlled trials are scarce.

METHODS

We retrospectively evaluated the survival rates, quality of life, ability to perform activities of daily living, and caregiver burden of 61 patients (aged from 37 to 83) who had previously undergone decompressive hemicraniectomy for malignant stroke between 2012 and 2017.

RESULTS

The mortality rate was higher among patients older than 60 years than among younger patients (71.0 % vs 36.7 %, p = 0.007; odds ratio 4.222, 95 % confidence interval 1.443-12.355). The mean survival time was 37.9 ± 6.0 months for 19 survivors of the younger group and 22.6 ± 5.7 months for 9 survivors of the older group. Among the 28 surviving patients, 22 (78.6 %) were interviewed, and we found that age was a determining factor for functional outcome (Barthel indices of 65.7 ± 10.6 for younger patients vs 48.0 ± 9.3 for older patients, p < 0.001), but not for quality of life. The caregiver burden was significantly correlated (R = -0.53, p < 0.01) with the severity of disability and age (R = 0.544, p = 0.011) of the patients.

CONCLUSION

Our findings show that the degree of impairment, as well as caregiver burden, is higher in patients older than 60 years than in younger patients.

Risk factors for bone flap resorption after autologous bone cranioplasty: Protocol for a systematic review and meta-analysis

BACKGROUND

One of the most common complications following autologous cranioplasty is bone flap resorption (BFR). Severe BFR can lead to revision surgery with implantation of synthetic bone flap and also necessarily lead to higher hospital expenses. This study aims to perform a meta-analysis to summarize available evidence regarding risk factors of BFR requiring a second surgery in patients with autologous cranioplasty.

METHODS

Cohort, case-control, and cross-sectional studies that report the incidence and risk factors of BFR among patients with autologous cranioplasty, published in English, will be considered for selection. Three databases from inception to May 2020 will be searched. The process of data selection, quality assessment, and data extraction will be assessed by 2 authors independently. The study quality will be assessed by Newcastle-Ottawa Scale (NOS) and Agency for Healthcare Research and Quality checklist.The statistical analysis of this meta-analysis will be calculated by Review manager version 5.3.

RESULTS

The results of this systematic review and meta-analysis will be disseminated through academic conferences and expected to publish in a peer-reviewed journal CONCLUSION:: This study will offer high-quality evidence about risk factors for BFR after autologous cranioplasty.

REGISTRATION NUMBER

INPLASY202050063.

Balancing the short-term benefits and long-term outcomes of decompressive craniectomy for severe traumatic brain injury

Introduction: The role of decompressive craniectomy in the management of neurological emergencies remains controversial. There is evidence available that it can reduce intracranial pressure, but it will not reverse the effects of the pathology that precipitated the neurological crisis, so there has always been concern that any reduction in mortality will result in an increase in the number of survivors with severe disability.Areas covered: The results of recent randomised controlled trials investigating the efficacy of the procedure are analyzed in order to determine the degree to which the short-term goals of reducing mortality and the long-term goals of a good functional outcome are achieved.Expert opinion: Given the results of the trials, there needs to be a change in the clinical decision-making paradigm such that decompression is reserved for patients who develop intractable intracranial hypertension and who are thought unlikely to survive without surgical intervention. In these circumstances, a more patient-centered discussion is required regarding the possibility and acceptability or otherwise of survival with severely impaired neurocognitive function.

Cranioplasty length of stay: Relationship with indication, surgical decision-making factors, and sex

Objectives

Cranioplasty is being performed more often due to rising rates of decompressive craniectomy. Hospital length of stay is a quality metric which has not been directly studied after cranioplasty. This study aims to identify factors associated with length of stay after cranioplasty to better understand their outcomes.

Patients and methods

A retrospective review was conducted at a single academic center from 2007 to 2015 for all patients >18 years of age who received cranioplasty. Baseline data from 148 patients were recorded including demographics, clinical characteristics, and surgeon decision-making factors for cranioplasty. Post-operative complications within 30 days after cranioplasty were recorded in addition to disposition and discharge data. Weibull accelerated failure time models were used to identify significant associations with length of stay after cranioplasty.

Results

The overall post-operative complication rate was 27.0%, and the most frequent indication for craniectomy was traumatic brain injury. The majority (72.3%) of patients returned home, compared to other disposition, and median length of stay was 2.0 days (interquartile range = 2.0). Average length of stay was 7.7 days in men, as compared with 2.4 days in women, and even upon adjusting for covariate effects, length of stay was longer in men than in women irrespective of post-operative complications. When time-to-cranioplasty fell between 0 and 30 days, average length of stay was 19.2 days, as compared with 10.3 days when time-to-cranioplasty fell between 30 and 90 days, and 2.5 days when time-to-cranioplasty was >90 days. After adjustment for covariate effects, the association between time-to-cranioplasty and length of stay was maintained only in patients without post-operative complications.

Conclusions

Length of stay can inform our understanding of outcomes after cranioplasty. In our study, length of stay was associated with sex, indication for craniectomy, and surgical decision-making (time-to-cranioplasty and implant material), but time-to-cranioplasty was only associated in patients without post-operative complications. These relationships should be seen not as direct causation, but rather as tools to add to our understanding of this relatively complicated procedure.

Evaluation of titanium mesh cranioplasty and polyetheretherketone cranioplasty: protocol for a multicentre, assessor-blinded, randomised controlled trial

INTRODUCTION

Cranioplasty is a common surgery in neurosurgery department. However, restoring the integrity of skull brings many challenges to surgeons, and the selection of ideal implant materials is throughout the history of cranioplasty. Although titanium mesh was still preferred by many neurosurgeons in cranial reconstruction, the new polyetheretherketone (PEEK) material, for example, is gaining popularity for craniofacial reconstruction today. There remain limited data that compare the outcome of PEEK cranioplasty and titanium mesh cranioplasty. It is necessary to conduct a study to compare outcome of different materials for cranioplasty.

METHODS/DESIGN

In this multicentre, assessor-blinded, randomised controlled study, we will randomise 140 patients in a 1:1 ratio to PEEK cranioplasty versus titanium cranioplasty. Eligible patients are adults who were diagnosed with cranial defect (due to severe traumatic brain injury, ischaemic stroke, haemorrhagic stroke, infiltrative tumour and so on), the defect size is over 25 cm², and they need to agree to participate in this trial. Instead of standard examinations, the enrolled patients receive neurological, motor, cognitive function and cerebral hemodynamics examinations as well as cosmetic evaluation. The procedures are repeated 3, 6 months after cranioplasty. The primary outcome, defined as infection or implant exposure after surgery, is the implant failure rate within 6 months. Secondary outcomes include postoperative complication rates, neurological outcomes, motor function, cerebral hemodynamics, cosmetic outcome and the total cost over a 6-month period.

ETHICS AND DISSEMINATION

This trial protocol has been approved by Biomedical Research Ethics Committee of West China Hospital of Sichuan University. All patients will be fully informed the implant materials, potential complications after surgery, responsibilities during the trial, and they will sign the informed consent before joining in this trial. If the patient's cognitive function is impaired, the patient's next of kin would be carefully informed. The results will be disseminated through academic conferences, student theses and will be published in a peer-reviewed journal.

TRAIL REGISTRATION NUMBER

ChiCTR1900024625; Pre-results.

Chapter 12: Decompressive Craniectomy: Long Term Outcome and Ethical Considerations

Decompressive craniectomy (DC) for the treatment of severe traumatic brain injury (TBI) has been established to decrease mortality. Despite the conclusion of the two largest randomized clinical trials associating the effectiveness of decompressive craniectomy vs. medical management for patients with traumatic brain injury (TBI), there is still clinical equipoise concerning the usefulness of DC in the management of refractory intracranial hypertension. Primary outcome data from these studies reveal either potential harm or that decreased mortality only leads to an upsurge in survivors with severe neurologic incapacity. In this chapter, we seek to review the results of the most recent clinical trials, highlight the prevailing controversies, and offer potential solutions to address this dilemma.

The application of polyetheretherketone (PEEK) implants in cranioplasty

Cranioplasty is a challenge to neurosurgeons, especially considering protection of intracranial contents. In recent years, material choice for cranioplasty is still controversial, which brings complexity to this seemingly straightforward procedure. PEEK, a tough, rigid, biocompatible material, has been used more recently in cranioplasty to provide better protection. The aim of this review is to summarize the outcome of research conducted on the material for cranioplasty applications. We also reviewed the comparison of PEEK with several common materials in previous articles. This is also the most complete data review article at present. In addition, the combination of nano-materials and PEEK is also a hotspot of research, so we have made a careful review of this aspect. We also summarized our own experience, telling about the future prospects of PEEK in the field of clinical cranioplasty should be highlighted. Improving the bioactivity, porosity, thinning, biocompatibility, antibacterial ability, integration and cost reduction of PEEK implants without affecting their mechanical properties is a major challenge.

Classification of bone flap resorption after cranioplasty: a proposal for a computed tomography-based scoring system

Background

Bone flap resorption (BFR) is the most prevalent complication resulting in autologous cranioplasty failure, but no consensus on the definition of BFR or between the radiological signs and relevance of BFR has been established. We set out to develop an easy-to-use scoring system intended to standardize the interpretation of radiological BFR findings.

Methods

All 45 autologous cranioplasty patients operated on at Oulu University Hospital from 2004 to 2014 were identified, and the bone flap status of all the available patients was evaluated using the new scoring system. Derived from previous literature, a three-variable score for the detection of BFR changes is proposed. The variables “Extent” (estimated remaining bone volume), “Severity” (possible perforations and their measured diameter), and “Focus” (the number of BFR foci within the flap) are scored from 0 to 3 individually. Using the sum of these scores, a score of 0–9 is assigned to describe the degree of BFR. Additionally, independent neurosurgeons assessed the presence and relevance of BFR from the same data set. These assessments were compared to the BFR scores in order to find a score limit for relevant BFR.

Results

BFR was considered relevant by the neurosurgeons in 11 (26.8%) cases. The agreement on the relevance of BFR demonstrated substantial strength (κ 0.64, 95%CI 0.36 to 0.91). The minimum resorption score in cases of relevant BFR was 5. Thus, BFR with a resorption score ≥ 5 was defined relevant (grades II and III). With this definition, grade II or III BFR was found in 15 (36.6%) of our patients. No risk factors were found to predict relevant BFR.

Conclusions

The score was proven to be easy to use and we recommend that only cases with grades II and III BFR undergo neurosurgical consultation. However, general applicability can only be claimed after validation in independent cohorts.

The Role of Decompressive Craniectomy in Limited Resource Environments

Decompressive craniectomy (DC) is a neurosurgical procedure useful to prevent and manage the impact of high intracranial pressure (ICP) that leads to brain herniation and brain's tissue ischemia. In well-resourced environment this procedure has been proposed as a last tier therapy when ICP is not controlled by medical therapies in the management of different neurosurgical emergencies like traumatic brain injury (TBI), stroke, infectious diseases, hydrocephalus, tumors, etc. The purpose of this narrative review is to discuss the role of DC in areas of low neurosurgical and neurocritical care resources. We performed a literature review with a specific search strategy in web repositories and some local and regional journals from Low and Middle-Income Countries (LMICs). The most common publications include case reports, case series and observational studies describing the benefits of the procedure on different pathologies but with several types of biases due to the absence of robust studies or clinical registries analysis in these kinds of environments.

Subcutaneous bone flap storage after emergency craniectomy: cost-effectiveness and rate of resorption

OBJECTIVEDecompressive craniectomy is used for uncontrolled intracranial pressure in traumatic brain injury and malignant hemispheric stroke. Subcutaneous preservation of the autologous bone flap in the abdomen is a simple, portable technique but has largely been abandoned due to perceived concerns of resorption. The authors sought to characterize their experience with subcutaneous preservation of the bone flap and cranioplasty.METHODSThe authors performed a retrospective single-institution review of subcutaneous preservation of the autologous bone flap after decompressive craniectomy from 2005 to 2015. The primary outcome was clinically significant bone resorption, defined as requiring a complete mesh implant at the time of cranioplasty, or delayed revision. The outcome also combined cases with any minor bone resorption to determine predictors of this outcome. Logistic regression modeling was used to determine the risk factors for predicting resorption. A cost comparison analysis was also used via the 2-sided t-test to compare the cost of cranioplasty using an autologous bone flap with standard custom implant costs.RESULTSA total of 193 patients with craniectomy were identified, 108 of whom received a cranioplasty. The mean time to cranioplasty was 104.31 days. Severe resorption occurred in 10 cases (9.26%): 4 were clinically significant (2 early and 2 late) and 6 demonstrated type II (severe) necrosis on CT, but did not require revision. Early resorption of any kind (mild or severe) occurred in 28 (25.93%) of 108 cases. Of the 108 patients, 26 (24.07%) required supplemental cranioplasty material. Late resorption of any kind (mild or severe) occurred in 6 (5.88%) of 102 cases. Of these, a clinically noticeable but nonoperative deformity was noted in 4 (3.92%) and minor (type I) necrosis on CT in 37 (37%) of 100. Bivariate analysis identified fragmentation of bone (OR 3.90, 95% CI 1.03-14.8), shunt-dependent hydrocephalus (OR 7.97, 95% CI 1.57-40.46), and presence of post-cranioplasty drain (OR 9.39, 95% CI 1.14-1000) to be significant risk factors for bone resorption. A binary logistic regression optimized using Fisher's scoring determined the optimal multivariable combination of factors. Fragmentation of bone (OR 5.84, 95% CI 1.38-28.78), diabetes (OR 7.61, 95% CI 1.37-44.56), and shunt-dependent hydrocephalus (OR 9.35, 95% CI 1.64-56.21) were found to be most predictive of resorption, with a C value of 0.78. Infections occurred in the subcutaneous pocket in 5 (2.60%) of the 193 cases and after cranioplasty in 10 (9.26%) of the 108 who underwent cranioplasty. The average cost of cranioplasty with autologous bone was $2156.28 ± $1144.60 (n = 15), and of a custom implant was $35,118.60 ± $2067.51 (3 different sizes; p < 0.0001).CONCLUSIONSCraniectomy with autologous bone cranioplasty using subcutaneous pocket storage is safe and compares favorably to cryopreservation in terms of resorption and favorably to a custom synthetic implant in terms of cost. While randomized data are required to definitively prove the superiority of one method, subcutaneous preservation has enough practical advantages with low risk to warrant routine use for most patients.

Complications of Decompressive Craniectomy

Decompressive craniectomy (DC) has become the definitive surgical procedure to manage medically intractable rise in intracranial pressure due to stroke and traumatic brain injury. With incoming evidence from recent multi-centric randomized controlled trials to support its use, we could expect a significant rise in the number of patients who undergo this procedure. Although one would argue that the procedure reduces mortality only at the expense of increasing the proportion of the severely disabled, what is not contested is that patients face the risk of a large number of complications after the operation and that can further compromise the quality of life. Decompressive craniectomy (DC), which is designed to overcome the space constraints of the Monro Kellie doctrine, perturbs the cerebral blood, and CSF flow dynamics. Resultant complications occur days to months after the surgical procedure in a time pattern that can be anticipated with advantage in managing them. New or expanding hematomas that occur within the first few days can be life-threatening and we recommend CT scans at 24 and 48 h postoperatively to detect them. Surgeons should also be mindful of the myriad manifestations of peculiar complications like the syndrome of the trephined and neurological deterioration due to paradoxical herniation which may occur many months after the decompression. A sufficiently large frontotemporoparietal craniectomy, 15 cm in diameter, increases the effectiveness of the procedure and reduces chances of external cerebral herniation. An early cranioplasty, as soon as the brain is lax, appears to be a reasonable choice to mitigate many of the late complications. Complications, their causes, consequences, and measures to manage them are described in this chapter.

Cranioplasty Using Autologous Bone versus Porous Polyethylene versus Custom-Made Titanium Mesh : A Retrospective Review of 108 Patients

Objective

The purpose of this study was to compare the cosmetic outcome and complications after cranioplasty (CP) due to three different implant materials, and analyze the mean implant survival and cumulative survival rate based on these results.

Methods

We reviewed 108 patients retrospectively who underwent CP between January 2014 and November 2016. Autologous bone (AB; 45 patients) and synthetic materials with porous polyethylene (PP; 32 patients) and custom-made 3-dimensional printed titanium mesh (CT; 31 patients) were used as implants.

Results

Regardless of implanted materials, more than 89.8% of the CP patients were satisfied with the cosmetic outcome. No statistically significant difference was observed among the three groups. The overall postoperative complication rates of each group were 31.1% in the AB group, 15.6% in the PP group and 3.2% in the CT group. The CT group showed lower complication rates compared with AB and PP groups (χ²-test : AB vs. PP, p=0.34; AB vs. CT, p=0.00; PP vs. CT, p=0.03). The AB and PP groups demonstrated a higher post-CP infection rate (11.1% and 6.3%) than the CT group (3.2%). However, no significant difference in the incidence of post-CP infection was observed among the three groups. The PP and CT groups demonstrated a higher mean implant survival time and cumulative survival rate than the AB group at the last follow-up (p<0.05).

Conclusion

In comparison with AB and PP, cranioplasty with CT shows benefits in terms of lower post-CP complication, less intraoperative bleeding loss, shorter operation time and in-hospital stay. The PP and CT groups showed higher implant survival time and cumulative survival rate compared with the AB group.

Decompressive craniectomy as salvage treatment in herpes simplex encephalitis: Two case reports

Herpes simplex encephalitis is a rare disease with significant morbidity and mortality, although targeted therapy is widely available. This report presents two cases of herpes simplex encephalitis in previously healthy, young adults treated with acyclovir, who developed severe brain edema. Decompressive craniectomy prevented imminent brain herniation and a fatal outcome in both of these patients.

A randomised controlled trial comparing autologous cranioplasty with custom-made titanium cranioplasty: long-term follow-up

OBJECTIVE

To compare the long-term outcomes of patients who had been randomly allocated to receive primary titanium cranioplasty or autologous bone graft following decompressive craniectomy.

METHODS

Sixty-four patients had been previously enrolled and randomised to receive either their own bone graft or a primary titanium cranioplasty. Functional and cosmetic outcomes had previously been assessed at 1-year following the cranioplasty procedure. Hospital records and the Picture Archiving communication system were reviewed to determine how many patients had cranioplasty failure or associated complications such as seizures beyond 1 year-with a minimum of 24-month follow-up.

RESULTS

Amongst the 31 patients in the titanium group (one patient had died), no patients had a partial or complete cranioplasty failure at 12 months follow-up and there had been no failures beyond 12 months. Amongst the 31 patients who had an autologous cranioplasty (one patient had died), 7 patients had complete resorption of the autologous bone such that it was adjudged a complete failure at 12-month follow-up. Five of these patients had had titanium augmentation and two patients declined further surgery. Both of these patients requested cranial augmentation for functional and cosmetic reasons subsequent to the 12-month follow-up. Another patient who had previously been noted to have moderate resorption at 12 months presented 1 year later with progressive bone flap resorption and also required subsequent augmentation for functional and cosmetic reasons. When follow-up was extended to a minimum of 24 months, use of titanium instead of autologous bone for primary cranioplasty resulted in a significant reduction in the number of patients who required rescue cranioplasty (0 vs 25%, 95% confidence interval [CI] 9.1-42.1%; p = 0.001). In addition, there were significantly less total hospital healthcare costs in those patients randomised to the titanium arm of the trial (difference = A$9999, 95%CI 2231-17,768; p = 0.015).

CONCLUSIONS

Bone resorption continued to occur beyond 12 months after autologous cranioplasty; use of primary titanium cranioplasty after decompressive craniectomy reduced the number of reoperations needed and the associated long-term total hospital costs.

Treatment of giant cavernous aneurysm in an elderly patient via extracranial-intracranial saphenous vein bypass graft in a hybrid operating room: A case report

RATIONALE

Extracranial-intracranial saphenous vein bypass (EC-IC SVB) remains indispensable for treating giant cavernous aneurysms. We report an unusual case of a giant cavernous aneurysm in an elderly patient treated with EC-IC SVB in a hybrid operating room. Immediately following proximal ligation of the internal carotid artery (ICA), she suffered an acute intraoperative encephalocele.

PATIENT CONCERNS

A 71-year-old woman had suffered from severe headache and double vision for 4 months.

DIAGNOSES

The woman was diagnosed with a right giant cavernous aneurysm.

INTERVENTIONS

She was treated with an EC-IC SVB with therapeutic ICA occlusion in the first biplane hybrid operating room in China. Just after proximal ligation of the ICA, she developed an acute encephalocele, and immediately underwent decompressive craniectomy. During the surgery she underwent 3 angiographic explorations.

OUTCOMES

After surgery, the aneurysm disappeared, and the graft was patent. Postoperative computed tomography and computed tomography angiography indicated a cranial defect and graft patency.

LESSONS

Although a hybrid operating room could improve the patency of grafts, the timing of ICA ligation for giant cavernous aneurysm via EC-IC bypass deserves further discussion. Second-stage ICA occlusion could offer an alternative for elderly patients requiring such treatment. In addition, cranial flap removal could prevent further neurologic deficits in a case of acute intraoperative encephalocele.

A study of the opinions of Swedish healthcare personnel regarding acceptable outcome following decompressive hemicraniectomy for ischaemic stroke

BACKGROUND

Decompressive hemicraniectomy (DC) is an established lifesaving treatment for malignant infarction of the middle cerebral artery (mMCAI). However, surgical decompression will not reverse the effects of the stroke and many survivors will be left severely disabled. The objective of this study was to assess what neurological outcome would be considered acceptable in these circumstances amongst Swedish healthcare workers.

METHOD

Healthcare workers were invited to participate in a presentation that outlined the pathophysiology of mMCAI, the rationale behind DC and outcome data from randomised controlled trials that have investigated efficacy of the procedure. They were then asked which neurological outcome would they feel to be acceptable based on the modified Rankin Score (mRS) and the Aphasia Handicap Scale (AHS). Information regarding sex, age, marital status, relatives, religion, earlier experience of stroke and occupation was also collected.

RESULTS

Six hundred and nine persons participated. The median accepted mRS was 3. An mRS of 4 or 5 was perceived to be acceptable by only 30.5% of participants. Therefore the most likely outcome, based on the results of the randomised controlled trials, would be unacceptable to most of the participants [OR 0.39 (CI, 0.22-0.69)]. The median accepted AHS was 3. A worst language outcome of restricted autonomy of verbal communication (AHS 3) or better would be accepted by 44.6%.

CONCLUSIONS

This study has highlighted the ethical problems when obtaining consent for DC following mMCAI, because for many of the participants the most likely neurological outcome would be deemed unacceptable. These issues need to be considered prior to surgical intervention and the time may have come for a broader societal discussion regarding the value of a procedure that converts death into survival with severe disability given the attendant financial and healthcare resource implications.

The therapeutic value of cranioplasty in individuals with brain injury

PRIMARY OBJECTIVE

To examine the effect of cranioplasty on recovery.

RESEARCH DESIGN

Retrospective cohort study.

METHOD AND PROCEDURES

Retrospective chart review conducted in 2011 and 2012 on adult inpatients with craniectomy who completed a continuous episode of inpatient rehabilitation before and after receiving their cranioplasty. Patients were matched 1:1 or age, gender, functional level at admission, injury severity and length of stay with inpatients who completed rehabilitation before cranioplasty. Main outcome measures include FIM^TM (Functional Independence Measure) and FIM^TM efficiency [(FIM^TM discharge - FIM^TMadmission)/number of days in rehabilitation]. To examine within and between group differences, analyses included paired and independent t-tests, Pearson correlations and chi-square analyses.

RESULTS

Twenty-six individuals (13 from the cranioplasty group and 13 from the comparison group) were analysed. FIM^TM efficiency increased following cranioplasty [0.29 to 0.61; t(12) = -2.77, p = 0.017]. The mean FIM^TM efficiency for the cranioplasty group was below that of the comparison group prior to cranioplasty [0.28 ± 0.37 and 0.39 ± 0.32, p = .41], but increased following cranioplasty [0.61 ± 0.71 and 0.39 ± 0.32, p = .32]. An improvement in FIM^TM efficiency following cranioplasty was more commonly seen among individuals with less severe brain injuries (75%, χ² = 3.8, df = 1, p = 0.053).

CONCLUSION

Rate of recovery increased following cranioplasty and exceeded that of the comparison group suggesting that cranioplasty may contribute to improvement.

Decompressive craniectomy in aneurysmal subarachnoid haemorrhage for hematoma or oedema versus secondary infarction

PURPOSE

Decompressive craniectomy (DC) has been proposed as lifesaving treatment in aneurysmal subarachnoid haemorrhage (aSAH) patients with elevated intracranial pressure (ICP). However, data is sparse and controversy exists whether the underlying cause of elevated ICP influences neurological outcome. The purpose of this study is to clarify the role of the underlying cause of elevated ICP on outcome after DC.

MATERIALS AND METHODS

We retrospectively studied the one-year neurological outcome in a single-centre cohort to identify predictors of favourable (Glasgow Outcome Scale (GOS) 4-5) and unfavourable (GOS 1-3) outcome. Additionally, available individual patient data in the literature was reviewed with a special emphasis on the underlying reason for DC.

RESULTS

From 2006-2015, 53 consecutive aSAH patients underwent DC. Nine (17%) achieved favourable, 44 (83%) unfavourable outcome (31 patients died). One fourth of the patients undergoing DC for hematoma or (hematoma-related) oedema survived favourably (increasing to 46% for patients aged <51 years), versus none of the patients undergoing DC for secondary infarction. Analysis of individual data of 105 literature patients showed a similar trend, although overall outcome was much better: half of the patients undergoing DC for hematoma/oedema regained independence, versus less than one-fourth of patients undergoing DC for secondary infarction.

CONCLUSIONS

DC in aSAH patients is associated with high rates of unfavourable outcome and mortality, but hematoma or oedema as underlying reason for DC is associated with better outcome profiles compared to secondary infarction. Future observational cohort studies are needed to further explore the different outcome profiles among subpopulations of aSAH patients requiring DC.

Cranial reconstruction using allogeneic mesenchymal stromal cells: A phase 1 first-in-human trial

Cranioplasty is necessary for patients that have undergone craniectomy following trauma, stroke or other causes of elevated intracranial pressure. This study assessed the effectiveness of treating cranial defects with allogeneic mesenchymal stromal cells (MSC) on a ceramic carrier and polymer scaffold, to produce viable bone and healing of a cranial void. Patients underwent a baseline computed tomography (CT) scan for construct design. Two sets of interlocking moulds were three-dimensional printed to enable shaping of two polymer meshes, which formed the boundaries of the construct corresponding to restoration of the skull interna and externa. In vitro expanded donor MSC were seeded onto ceramic granules in a good manufacturing practices facility. The inner mesh was placed in theatre, followed by the cell-loaded granules, and the outer mesh. Patients were followed-up at 3, 6 and 12 months and cosmesis assessed visually, while bone formation was assessed by CT scans at 1 day, 3 months and 12 months. Manufacture of the construct and surgery was uneventful for all three patients. Initial cosmesis was excellent with no complications. New bone formation was demonstrated by analysis of CT data; however, bone resorption was noted in all 3 cases on the 12-month CT scan. The lack of rigidity of the construct in an environment with continuous pulsatile movement may be preventing the formation of solid bone. It is possible to produce a customized allogeneic MSC construct for cranial reconstruction to replace cranial bone with good cosmesis, using a combination of medical computer modelling, rapid-prototyping and tissue engineering.

Predicting long-term neurological outcomes after severe traumatic brain injury requiring decompressive craniectomy: A comparison of the CRASH and IMPACT prognostic models

BACKGROUND

Predicting long-term neurological outcomes after severe traumatic brain (TBI) is important, but which prognostic model in the context of decompressive craniectomy has the best performance remains uncertain.

METHODS

This prospective observational cohort study included all patients who had severe TBI requiring decompressive craniectomy between 2004 and 2014, in the two neurosurgical centres in Perth, Western Australia. Severe disability, vegetative state, or death were defined as unfavourable neurological outcomes. Area under the receiver-operating-characteristic curve (AUROC) and slope and intercept of the calibration curve were used to assess discrimination and calibration of the CRASH (Corticosteroid-Randomisation-After-Significant-Head injury) and IMPACT (International-Mission-For-Prognosis-And-Clinical-Trial) models, respectively.

RESULTS

Of the 319 patients included in the study, 119 (37%) had unfavourable neurological outcomes at 18-month after decompressive craniectomy for severe TBI. Both CRASH (AUROC 0.86, 95% confidence interval 0.81-0.90) and IMPACT full-model (AUROC 0.85, 95% CI 0.80-0.89) were similar in discriminating between favourable and unfavourable neurological outcome at 18-month after surgery (p=0.690 for the difference in AUROC derived from the two models). Although both models tended to over-predict the risks of long-term unfavourable outcome, the IMPACT model had a slightly better calibration than the CRASH model (intercept of the calibration curve=-4.1 vs. -5.7, and log likelihoods -159 vs. -360, respectively), especially when the predicted risks of unfavourable outcome were <80%.

CONCLUSIONS

Both CRASH and IMPACT prognostic models were good in discriminating between favourable and unfavourable long-term neurological outcome for patients with severe TBI requiring decompressive craniectomy, but the calibration of the IMPACT full-model was better than the CRASH model.

Uncertainty, conflict and consent: revisiting the futility debate in neurotrauma

The concept of futility has been debated for many years, and a precise definition remains elusive. This is not entirely unsurprising given the increasingly complex and evolving nature of modern medicine. Progressively more complex decisions are required when considering increasingly sophisticated diagnostic and therapeutic interventions. Allocating resources appropriately amongst a population whose expectations continue to increase raises a number of ethical issues not least of which are the difficulties encountered when consideration is being given to withholding "life-preserving" treatment. In this discussion we have used decompressive craniectomy for severe traumatic brain injury as a clinical example with which to frame an approach to the concept. We have defined those issues that initially lead us to consider futility and thereafter actually provoke a significant discussion. We contend that these issues are uncertainty, conflict and consent. We then examine recent scientific advances in outcome prediction that may address some of the uncertainty and perhaps help achieve consensus amongst stakeholders. Whilst we do not anticipate that this re-framing of the idea of futility is applicable to all medical situations, the approach to specify patient-centred benefit may assist those making such decisions when patients are incompetent to participate.

Management of the temporal muscle during cranioplasty: technical note

Over the past 2 decades there has been a resurgence of interest in the use of decompressive craniectomy in the management of neurological emergencies. While technically straightforward, the procedure is associated with a number of complications relating to the initial decompression and subsequent cranioplasty. One complication that has received relatively little attention relates to the management of the temporal muscle. Here, through an illustrative case, the author describes a novel method of minimizing dissection of the temporal muscle during a cranioplasty procedure. Rather than placing a synthetic material over the dura mater to prevent adhesions or dissecting the muscle off the dura, the dura was opened and reflected laterally, pedicled to the temporal muscle. The dural defect was closed with a dural substitute, and the bone flap was secured in a routine fashion. The temporal muscle was then secured in its anatomical position. At the 6-month follow-up, radiological and clinical examination confirmed the restoration of muscle volume with excellent cosmetic and functional results. Opening the dura on a temporal muscle pedicle does not represent a routine form of surgical reconstruction; however, the use of this technique may have some advantages especially in young patients who have made a good recovery and for whom facial aesthetics may be particularly important.

A randomized controlled trial comparing autologous cranioplasty with custom-made titanium cranioplasty

OBJECTIVE Autologous bone is usually used to reconstruct skull defects following decompressive surgery. However, it is associated with a high failure rate due to infection and resorption. The aim of this study was to see whether it would be cost-effective to use titanium as a primary reconstructive material. METHODS Sixty-four patients were enrolled and randomized to receive either their own bone or a primary titanium cranioplasty. All surgical procedures were performed by the senior surgeon. Primary and secondary outcome measures were assessed at 1 year after cranioplasty. RESULTS There were no primary infections in either arm of the trial. There was one secondary infection of a titanium cranioplasty that had replaced a resorbed autologous cranioplasty. In the titanium group, no patient was considered to have partial or complete cranioplasty failure at 12 months of follow-up (p = 0.002) and none needed revision (p = 0.053). There were 2 deaths unrelated to the cranioplasty, one in each arm of the trial. Among the 31 patients who had an autologous cranioplasty, 7 patients (22%) had complete resorption of the autologous bone such that it was deemed a complete failure. Partial or complete autologous bone resorption appeared to be more common among young patients than older patients (32 vs 45 years old, p = 0.013). The total cumulative cost between the 2 groups was not significantly different (mean difference A$3281, 95% CI $-9869 to $3308; p = 0.327). CONCLUSIONS Primary titanium cranioplasty should be seriously considered for young patients who require reconstruction of the skull vault following decompressive craniectomy. Clinical trial registration no.: ACTRN12612000353897 ( anzctr.org.au ).

The Incidence of Neurologic Susceptibility to a Skull Defect

OBJECTIVE

To determine whether there is a measureable change in neurologic function after cranioplasty.

METHODS

This is a prospective single-surgeon, single-center study. Fifty patients who required a cranioplasty procedure were assessed neurologically within 72 hours before and 7 days after surgery. The assessment tools were the Functional Independence Measure (FIM) and the Cognitive assessment report (Cognistat). The scores for both assessments were calculated and then compared before and after surgery.

RESULTS

FIM assessment was performed on all fifty patients, and a Cognistat assessment was performed on 47 patients. Most improvements were seen in the Cognistat scores; however, there appeared to be no specific areas in which there was consistent improvement. There were substantial improvements in the Cognistat assessment in 9 patients. One patient had a much-improved FIM assessment (improved from 18 to 34), but a Cognistat assessment was not possible because of poor neurologic function. These results suggested that improvements after cranioplasty were more likely to occur in the domain of cognitive function than motor function, although overall these results did not reach statistically significance. Bifrontal (vs. unilateral) cranioplasty, timing between decompression and cranioplasty, and age of the patients did not appear to affect the postoperative FIM scores, after we adjusted for preoperative FIM scores and surgical complications.

CONCLUSIONS

A small but significant number of patients appear to improve clinically after cranioplasty. Neurologic susceptibility to a skull defect may be more common than had been appreciated previously.

ORACLE Stroke Study

BACKGROUND:

There continues to be considerable interest in the use of decompressive hemicraniectomy in the management of malignant cerebral artery infarction; however, concerns remain about long-term outcome.

OBJECTIVE:

To assess opinion on consent and acceptable outcome among a wide range of healthcare workers.

METHODS:

Seven hundred seventy-three healthcare workers at the 2 major public neurosurgical centers in Western Australia participated. Participants were asked to record their opinion on consent and acceptable outcome based on the modified Rankin Score (mRS). The evidence for clinical efficacy of the procedure was presented, and participants were then asked to reconsider their initial responses.

RESULTS:

Of the 773 participants included in the study, 407 (52.7%) initially felt that they would provide consent for a decompressive craniectomy as a lifesaving procedure, but only a minority of them considered an mRS score of 4 or 5 an acceptable outcome (for mRS score ⩽4, n = 67, 8.7%; for mRS score = 4, n = 57, 7.4%). After the introduction of the concept of the disability paradox and the evidence for the clinical efficacy of decompressive craniectomy, more participants were unwilling to accept decompressive craniectomy (18.1% vs 37.8%), but at the same time, more were willing to accept an mRS score ⩽4 as an acceptable outcome (for mRS score ⩽4, n = 92, 11.9%; for mRS score = 4, n = 79, 10.2%).

CONCLUSION:

Most participants felt survival with dependency to be unacceptable. However, many would be willing to provide consent for surgery in the hopes that they may survive with some degree of independence.

The feasibility of producing patient-specific acrylic cranioplasty implants with a low-cost 3D printer

OBJECT Commercially available, preformed patient-specific cranioplasty implants are anatomically accurate but costly. Acrylic bone cement is a commonly used alternative. However, the manual shaping of the bone cement is difficult and may not lead to a satisfactory implant in some cases. The object of this study was to determine the feasibility of fabricating molds using a commercial low-cost 3D printer for the purpose of producing patient-specific acrylic cranioplasty implants. METHODS Using data from a high-resolution brain CT scan of a patient with a calvarial defect posthemicraniectomy, a skull phantom and a mold were generated with computer software and fabricated with the 3D printer using the fused deposition modeling method. The mold was used as a template to shape the acrylic implant, which was formed via a polymerization reaction. The resulting implant was fitted to the skull phantom and the cranial index of symmetry was determined. RESULTS The skull phantom and mold were successfully fabricated with the 3D printer. The application of acrylic bone cement to the mold was simple and straightforward. The resulting implant did not require further adjustment or drilling prior to being fitted to the skull phantom. The cranial index of symmetry was 96.2% (the cranial index of symmetry is 100% for a perfectly symmetrical skull). CONCLUSIONS This study showed that it is feasible to produce patient-specific acrylic cranioplasty implants with a low-cost 3D printer. Further studies are required to determine applicability in the clinical setting. This promising technique has the potential to bring personalized medicine to more patients around the world.

Aggressive operative treatment of isolated blunt traumatic brain injury in the elderly is associated with favourable outcome

Outcome after traumatic brain injury (TBI) in the elderly has not been fully elucidated. The present retrospective observational study investigates the age-dependent outcome of patients suffering from severe isolated TBI with regard to operative and non-operative treatment. Data were prospectively collected in the TraumaRegister DGU. Anonymous datasets of 8629 patients with isolated severe blunt TBI (AISHead≥3, AISBody≤1) documented from 2002 to 2011 were analysed. Patients were grouped according to age: 1-17, 18-59, 60-69, 70-79 and ≥80 years. Cranial fractures (44.8%) and subdural haematomas (42.6%) were the most common TBIs. Independent from the type of TBI the group of patients with operative treatment declined with rising age. Subgroup analysis of patients with critical TBI (AISHead=5) revealed standardised mortality ratios (SMRs) of 0.81 (95% CI 0.75-0.87) in case of operative treatment (n=1201) and 1.13 (95% CI 1.09-1.18) in case of non-operative treatment (n=1096). All age groups ≥60 years showed significantly reduced SMRs in case of operative treatment. Across all age groups the group of patients with low/moderate disability according to the GOS (4 or 5 points) was higher in case of operative treatment. Results of this retrospective observational study have to be interpreted cautiously. However, good outcome after TBI with severe space-occupying haemorrhage is more frequent in patients with operative treatment across all age groups. Age alone should not be the reason for limited care or denial of operative intervention.