Long-Term Complications of Decompressive Craniectomy for Head Injury

Immune-based strategies for the treatment of biofilm infections

Biofilms are bacterial communities surrounded by a polymeric matrix that can form on implanted materials and biotic surfaces, resulting in chronic infection that is recalcitrant to immune- and antibiotic-mediated clearance. Therefore, biofilm infections present a substantial clinical challenge, as treatment often involves additional surgical interventions to remove the biofilm nidus, prolonged antimicrobial therapy to clear residual bacteria, and considerable risk of treatment failure or infection recurrence. These factors, combined with progressive increases in antimicrobial resistance, highlight the need for alternative therapeutic strategies to circumvent undue morbidity, mortality, and resource strain on the healthcare system resulting from biofilm infections. One promising option is reprogramming dysfunctional immune responses elicited by biofilm. Here, we review the literature describing immune responses to biofilm infection with a focus on targets or strategies ripe for clinical translation. This represents a complex and dynamic challenge, with context-dependent host-pathogen interactions that differ across infection models, microenvironments, and individuals. Nevertheless, consistencies among these variables exist, which could facilitate the development of immune-based strategies for the future treatment of biofilm infections.

Pons herniation after skull base chondrosarcoma surgery: A rare complication after transclival endoscopic endonasal approach

Background

Intracranial chondrosarcomas are malignant tumors that most commonly affect the clivus region. For tumors in this location, the extended endoscopic endonasal approach could offer an alternative route. We present a case of pons herniation after this technique.

Case Description

A 55-year-old female presented with a 6-month history of difficulty walking. The neurological evaluation showed asymmetric tetra paresis and involvement of the IX cranial nerve on the right side. Imaging exams showed a lesion at the upper clivus, with a possible diagnosis of chondrosarcoma. An extended transclival approach with partial resection and a multilayer closure were performed. The patient had a slight immediate improvement in muscle strength, and she was discharged home 5 days after surgery. Four weeks later, she evolved with worsening strength on the left side. A new image examination revealed an atypical protrusion of the pontine tissue through the bone defect at the opening of the clivus; a surgical revision was proposed, but the patient chose conservative management.

Conclusion

Pontine herniation is a rare complication with no defined cause. The use of a rigid material for closure could reduce the chances of this complication, but futher studies are necessary to reinforce that hypothesis.

Dynamic Craniotomy With Khanna NuCrani Plates as an Alternative to Craniotomy With Fixed Plates in Traumatic Brain Injury

BACKGROUND AND OBJECTIVES

Dynamic craniotomy as opposed to a fixed plate craniotomy provides cranial decompression with a controlled outward bone flap movement to accommodate postoperative cerebral swelling and/or hemorrhage. The objective of this study was to evaluate if fixation of the bone flap following a trauma craniotomy with dynamic plates provides any advantage over fixed plates.

METHODS

A review of our clinical series of 25 consecutive adult patients undergoing dynamic craniotomy with the Khanna NuCrani reversibly expandable bone flap fixation plates for the treatment of traumatic brain injury associated with mass lesions including subdural, epidural, and cerebral hematomas was conducted.

RESULTS

Postoperative cerebral swelling was encountered in 21 of 25 patients (84%), which was compensated for with outward bone flap movement in all these patients and associated decreased midline shift. Severe brain swelling with outward bone flap movement of 8 mm or more was noted in 40% of the patients. All patients had a normal intracranial pressure after surgery. None of the patients required any reoperations for hematoma evacuation, rescue decompressive craniectomies, cranioplasty, or complications related to wound healing. The bone flap retracted after the resolution of the brain swelling, and none of the patients reported cosmetic symptoms related to bone flap or wound healing. Overall, 84% (21 of 25) of the patients achieved a good outcome.

CONCLUSION

Craniotomy bone flap fixation with dynamic plates is an alternative to craniotomy with fixed plates. The main advantage of dynamic craniotomy over a craniotomy with fixed plates is that it allows for immediate intracranial volume expansion with reversible outward bone flap migration in patients who may develop postoperative worsening brain swelling and/or hemorrhage, with decreased need for repeat surgeries and associated complications.

Revision Cranioplasty with Three-dimensional Custom-made Titanium Implants in Patients with Failed Cranioplasty

OBJECTIVE

Graft failure is a common complication of cranioplasty. Revision cranioplasty is required to overcome this complication. However, no previous studies have reported outcomes in revision cranioplasty with 3-dimensional (3D) custom-made titanium implants. We describe our experience with 3D titanium implants in patients with revision cranioplasty.

METHODS

We evaluated 43 consecutive patients between January 2011 and December 2019 who underwent revision cranioplasty using 3D custom-made titanium implants. The 3D image of the patient's cranium and the plan to close the cranium defect were created in a virtual environment using software programs. Demographic and radiologic features were compared based on the materials used in the initial cranioplasty.

RESULTS

Previous material was autologous graft (AG) in 27 patients and polymethyl methacrylate (PMMA) in 16 patients. The mean time without revision cranioplasty is longer in patients with PMMA implants than in patients with AG. There was no statistically significant difference in the length of hospital stay between patients with PMMA implants and patients with AG. There were no postoperative adverse events such as infection, wound dehiscence, convulsions, or epidural hematoma in 38 patients during hospitalization. Wound dehiscence developed in 5 patients and surgical repair was required in one.

CONCLUSIONS

Initial cranioplasty with PMMA provides a longer time period than the AG before the revision. However, both of them have similar outcomes based on length of hospital stay and cranial defect area. Custom-made 3D titanium implant is a good option for revision cranioplasty to prevent implant failure and reduce patients' cosmetic concerns.

Partial Cranial Reconstruction Using Titanium Mesh after Craniectomy: An Antiadhesive and Protective Barrier with Improved Aesthetic Outcomes

OBJECTIVE

Describe a new, safe, technique that uses titanium mesh to partially cover skull defects immediately after decompressive craniectomy (DC).

METHODS

This study is a retrospective review of 8 patients who underwent DC and placement of a titanium mesh. The mesh partially covered the defect and was placed between the temporalis muscle and the dura graft. The muscle was sutured to the mesh. All patients underwent cranioplasty at a later time. The study recorded and analyzed demographic information, time between surgeries, extra-axial fluid collections, postoperative infections, need for reoperation, cortical hemorrhages, and functional and aesthetic outcomes.

RESULTS

After craniectomy, all patients underwent cranioplasty within an average of 112.5 days (30-240 days). One patient reported temporalis muscle atrophy, which was the only complication observed. During the cranioplasties, no adhesions were found between temporalis muscle, titanium mesh, and underlying dura. None of the patients showed complications in the follow-up computerized tomography scans. All patients had favorable aesthetic and functional results.

CONCLUSIONS

Placing a titanium mesh as an extra step during DC could have antiadhesive and protective properties, facilitating subsequent cranioplasty by preventing adhesions and providing a clear surgical plane between the temporalis muscle and intracranial tissues. This technique also helps preserve the temporalis muscle and enhances functional and aesthetic outcomes postcranioplasty. Therefore, it represents a safe alternative to other synthetic anti-adhesive materials. Further studies are necessary to draw definitive conclusions and elucidate long-term outcomes, however, the results obtained hold great promise for the safety and efficacy of this technique.

Subcutaneous preservation versus cryopreservation of autologous bone grafts for cranioplasty: A systematic review and meta-analysis

BACKGROUND

Cranioplasty corrects cranial bone defects using various bone substitutes or autologous bone flaps created during a previous craniectomy surgery. These autologous bone flaps can be preserved through subcutaneous preservation (SP) or cryopreservation (CP).

AIM

We aim to compare outcomes and complications for both SP and CP techniques to enhance the current evidence about autologous bone flap preservation.

METHODS

Five electronic databases were searched to collect all relevant studies. Records were screened for eligibility. Data were extracted from the included studies independently. We categorized surgical site infection (SSI) as either due to Traumatic brain injury (TBI) or not to reveal potential variations in SSI incidence. The double-arm meta-analysis utilized risk ratios (RR) and mean differences (MD) with corresponding confidence intervals (CI) to pool categorical and continuous outcomes, respectively. Proportions with their respective 95% CIs were pooled for single-arm meta-analyses to determine outcomes related to SP technique.

RESULTS

Seventeen studies involving 1169 patients were analyzed. No significant difference in SSI rates was observed between SP and CP methods in patients with or without TBI. SP was linked to shorter hospital stays in two studies (194 patients). Single-arm analysis showed a 17% revision surgery rate across five studies (375 patients) and infection rates in 17 studies for SP. New bone formation occurred in 13.2% of patients, with 19.9% showing resorption.

CONCLUSION

SP and CP methods showed similar SSI rates post-craniectomy in TBI and non-TBI patients. SP was associated with reduced hospitalization time, low infection rates, and a moderate need for revision surgery.

Prolonged course of brain edema and neurological recovery in a translational model of decompressive craniectomy after closed head injury in mice

Background

The use of decompressive craniectomy in traumatic brain injury (TBI) remains a matter of debate. According to the DECRA trial, craniectomy may have a negative impact on functional outcome, while the RescueICP trial revealed a positive effect of surgical decompression, which is evolving over time. This ambivalence of craniectomy has not been studied extensively in controlled laboratory experiments.

Objective

The goal of the current study was to investigate the prolonged effects of decompressive craniectomy (both positive and negative) in an animal model.

Methods

Male mice were assigned to the following groups: sham, decompressive craniectomy, TBI and TBI followed by craniectomy. The analysis of functional outcome was performed at time points 3d, 7d, 14d and 28d post trauma according to the Neurological Severity Score and Beam Balance Score. At the same time points, magnetic resonance imaging was performed, and brain edema was analyzed.

Results

Animals subjected to both trauma and craniectomy presented the exacerbation of the neurological impairment that was apparent mostly in the early course (up to 7d) after injury. Decompressive craniectomy also caused a significant increase in brain edema volume (initially cytotoxic with a secondary shift to vasogenic edema and gliosis). Notably, delayed edema plus gliosis appeared also after decompression even without preceding trauma.

Conclusion

In prolonged outcomes, craniectomy applied after closed head injury in mice aggravates posttraumatic brain edema, leading to additional functional impairment. This effect is, however, transient. Treatment options that reduce brain swelling after decompression may accelerate neurological recovery and should be explored in future experiments.

Study protocol for a multicenter randomized controlled pilot study on decompressive laparotomy vs. decompressive craniectomy for intractable intracranial pressure after traumatic brain injury: The SCALPEL study

Introduction

Decompressive craniectomy (DC) is the ultimate intervention to lower intracranial pressure (ICP) following severe traumatic brain injury (TBI). However, this intervention is associated with considerable adverse events and a higher proportion of survivors with poor functional outcomes.

Research question

In a multicompartment system ICP is associated with intraabdominal pressure (IAP) due to cerebral venous outflow from the brain. This is the rationale for decompressive laparotomy (DL) to control ICP after TBI as reported by experimental and retrospective clinical data. The safety profile of DL is superior to DC. This study aims to randomly assign patients with intractable high ICP after severe TBI to DL or DC.

Material and methods

Among other inclusion criteria, ICP must be above 20 mmHg (1-12 h) despite sedation and all other measures according to current guidelines. The primary outcome is the Extended Glasgow Outcome Scale assessed after twelve months. Further secondary outcome measures are compartmental pressure values, complications, etc. After 20 initial patients, results will be reviewed by the ethics committees and safety monitoring board to decide on the enrolment of 80 additional patients.

Results

The study is designed to provide not only high-quality prospective data for the first time on this treatment approach, its two-stage design (20 + 80 pts) also provides maximum patient safety. This protocol conforms with the SPIRIT 2013 Statement. Ethics approval was granted by our but also 5 other university ethics committees (registration 473/18S).

Conclusion

Registration was performed prior to study initiation in November 2021 (registration number NCT05115929).

Massive Solubility Changes in Neuronal Proteins upon Simulated Traumatic Brain Injury Reveal the Role of Shockwaves in Irreversible Damage

We investigated the immediate molecular consequences of traumatic brain injuries (TBIs) using a novel proteomics approach. We simulated TBIs using an innovative laboratory apparatus that employed a 5.1 kg dummy head that held neuronal cells and generated a ≤4000 g-force acceleration upon impact. A Proteome Integral Solubility Alteration (PISA) assay was then employed to monitor protein solubility changes in a system-wide manner. Dynamic impacts led to both a reduction in neuron viability and massive solubility changes in the proteome. The affected proteins mapped not only to the expected pathways, such as those of cell adhesion, collagen, and laminin structures, as well as the response to stress, but also to other dense protein networks, such as immune response, complement, and coagulation cascades. The cellular effects were found to be mainly due to the shockwave rather than the g-force acceleration. Soft materials could reduce the impact's severity only until they were fully compressed. This study shows a way of developing a proteome-based meter for measuring irreversible shockwave-induced cell damage and provides a resource for identifying protein biomarkers of TBIs and potential drug targets for the development of products aimed at primary prevention and intervention.

Hinge craniotomy as an alternative technique for patients with refractory intracranial hypertension

Introduction

Decompressive craniectomy (DC) can save brain tissue, but unfortunately it has many limitations and complications. Hinge craniotomy (HC), as less aggressive method seems to be adequate alternative not only to DC but also to conservative treatment.

Research question

Presentation of the results of modified surgical techniques of cranial decompression and comparing with more and less aggressive medical options.

Material and methods

A prospective clinical study was conducted during 86 months. Comatose patients who suffered refractory intracranial hypertension (RIH) were treated. Altogether, 137 patients have been evaluated. The final outcome of all patients in the study was evaluated after 6 months.

Results

Both surgical options resulted in adequate control of intracranial pressure (ICP). HC method was shown to have the lowest probability of worsening from a prior state of relative stability.

Discussion and conclusion

There was no statistically significant difference between methods to treatment of DC or HC, meaning the final outcome of patients treated in any manner. There was similar rate of early and late complications.

The Role of Decompressive Craniectomy on Functional Outcome, Mortality and Seizure Onset after Traumatic Brain Injury

BACKGROUND

Decompressive craniectomy (DC) to treat increased intracranial pressure after a traumatic brain injury (TBI) is a common but controversial choice in clinical practice. This study aimed to determine the impact of DC on functional outcomes, mortality and the occurrence of seizures in a large cohort of patients with TBI.

METHODS

This retrospective study included patients with TBI consecutively admitted for a 6-month neurorehabilitation program between 1 January 2009 and 31 December 2018. The radiological characteristics of brain injury were determined with the Marshall computed tomographic classification. The neurological status and rehabilitation outcome were assessed using the Glasgow Coma Scale (GCS) and the Functional Independence Measure (FIM), which were both assessed at baseline and on discharge. Furthermore, the GCS was recorded on arrival at the emergency department. The DC procedure, prophylactic antiepileptic drug (AED) use, the occurrence of early or late seizures (US, unprovoked seizures) and death during hospitalization were also recorded.

RESULTS

In our cohort of 309 adults with mild-to-severe TBI, DC was performed in 98 (31.7%) patients. As expected, a craniectomy was more frequently performed in patients with severe TBI (p < 0.0001). However, after adjusting for the confounding variables including GCS scores, age and the radiological characteristics of brain injury, there was no association between DC and poor functional outcomes or mortality during the inpatient rehabilitation period. In our cohort, the independent predictors of an unfavorable outcome at discharge were the occurrence of US (β = -0.14, p = 0.020), older age (β = -0.13, p = 0.030) and the TBI severity on admission (β = -0.25, p = 0.002). Finally, DC (OR 3.431, 95% CI 1.233-9.542, p = 0.018) and early seizures (OR = 3.204, 95% CI 1.176-8.734, p = 0.023) emerged as the major risk factors for US, independently from the severity of the brain injury and the prescription of a primary prophylactic therapy with AEDs.

CONCLUSIONS

DC after TBI represents an independent risk factor for US, regardless of the prescription of prophylactic AEDs. Meanwhile, there is no significant association between DC and mortality, or a poor functional outcome during the inpatient rehabilitation period.

Unemployment Status Subsequent to Cancer Diagnosis and Therapies: A Systematic Review and Meta-Analysis

The purpose of our study is to examine whether cancer and treatments are associated with job loss or changes in employment status. Eight prospective studies were included in the systematic review and meta-analysis, with a population aged 18-65 years, analyzing treatment regimen and psychophysical and social status in post-cancer follow-up of at least 2 years. In the meta-analysis, a comparison was made between recovered unemployed cases and cases from a standard reference population. Results are summarized graphically using a forest plot. We showed that cancer and subsequent treatment are risk factors for unemployment with an overall relative risk of 7.24 (lnRR: 1.98, 95% CI: 1.32-2.63) or for change in employment status. Individuals undergoing chemotherapy and/or radiation treatment and those with brain and colorectal cancers are more likely to develop disabilities that negatively affect the risk of unemployment. Finally, variables such as low level education, female sex, older age, and being overweight before starting therapy are associated with higher risk of unemployment. In the future, it will be necessary for people with cancer to have access to specific health, social welfare, and employment support programs. In addition, it is desirable that they become more involved in their choice of therapeutic treatment.

Decompressive Craniectomy in Pediatric Traumatic Brain Injury: A Retrospective Cohort Study

Decompressive craniectomy (DC) in children with traumatic brain injury (TBI) and refractory raised intracranial pressure (ICP) remains controversial. We aimed to describe the clinical and operative characteristics of children with moderate to severe TBI who underwent DC, and compare outcomes with those who had medical therapy. We performed a retrospective observational cohort study on children < 16 years of age with moderate to severe TBI (Glasgow coma scale [GCS] ≤13) who underwent DC in two pediatric centers in Singapore and China between 2014 and 2017, and compared their outcomes with children who underwent medical treatment, among participating centers of the Pediatric Acute and Critical Care Medicine Asian Network. We defined poor functional outcomes as moderate, severe disability, vegetative or comatose state, or mortality, using the Pediatric Cerebral Performance Category scale. We performed multivariable logistic regression to identify predictors for poor functional outcomes. We analyzed 18 children who underwent DC with 214 who had medical therapy. A greater proportion of children with DC (14, 77.8%) experienced poor functional outcomes, compared with those with medical therapy (87, 41.2%, p = 0.003). Children who underwent DC had fewer median 14-day intensive care unit (ICU)-free days (2.5 days, interquartile range [IQR]: 0.0–5.8 vs. 8.0 days, IQR: 0.0–11.0, p = 0.033), median 28-day hospital-free days (0 day, IQR: 0.0–3.5 vs. 11.0 days, IQR: 0.0–21.0, p = 0.002) and 14-day mechanical ventilation-free days (6.5 days, IQR: 0.0–12.3 vs. 11.0 days, IQR: 3.0–14.0, p = 0.011). After accounting for age, sex, GCS, cerebral edema, uncal herniation, nonaccidental injury, and need for intubation, there was no significant association between DC and poor functional outcomes (adjusted odds ratio: 1.59, 95% confidence interval: 0.35–7.24, p = 0.548). Children with DC had severe injuries, and prolonged hospital and ICU stays. Future studies are needed to understand the effectiveness of DC on children with TBI.

Surgery for acute subdural hematoma: the value of pre-emptive decompressive craniectomy by propensity score analysis

BACKGROUND

Acute subdural hematomas (ASDH) are found frequently following traumatic brain injury (TBI) and they are considered the most lethal type of mass lesions. The decision to perform a procedure to evacuate ASDH and the approach, either via craniotomy or decompressive craniectomy (DC), remains controversial.

METHODS

We reviewed a prospectively collected series of 343 moderate to severe TBI patients in whom ASDH was the main lesion (ASDH volumes ≥10 cc). Patients with early comfort measures (early mortality prediction >50% and not ICP monitored), bilateral ASDH or the presence of another intracranial hematoma with volumes exceeding two times the volume of the ASDH were excluded. Among them, 112 were managed conservatively, 65 underwent ASDH evacuation by craniotomy and 166 by DC (103 pre-emptive DC, 63 obligatory DC). We calculated the average treatment effect by propensity score (PS) analysis using the following covariates: age, year, hypoxia, shock, pupils, major extracranial injury, motor score, midline shift, ASDH volume, swelling, intraventricular and subarachnoid hemorrhage presence. Then, multivariable binary regression and ordinal logistic regression analysis were performed to estimate associations between predictors and mortality and 12 months-GOS respectively. The patients' inverse probability weights were included as an independent variable in both regression models.

RESULTS

The main variables associated with outcome were year, age, falls from patient´s own height, hypoxia, early deterioration, pupillary abnormalities, basal cistern effacement, compliance to ICP monitoring guidelines and type of surgical approach (craniotomy and pre-emptive DC).

CONCLUSIONS

According to sliding dichotomy analysis, we found that patients in the intermediate or worst bands of unfavorable outcome prognosis seemed to achieve better than expected outcome if they underwent pre-emptive DC rather than craniotomy.

Malignant cerebral edema after cranioplasty: a case report and literature review

BACKGROUND

Cranioplasty is a common surgery in the neurosurgery for patients with skull defects following decompression craniectomy. Concomitant rare complications are increasingly reported, such as malignant cerebral edema after cranioplasty.

CASE REPORT

A 45-year-old man underwent decompression craniectomy due to traumatic brain injury. At 3 months after the decompression craniectomy, the patient developed refractory subdural hydrogen and received ipsilateral refractory subdural effusion capsule resection, but no significant relief was seen. Therefore, the cranioplasty was decided to treat subdural hydrogen and restore the normal appearance of the skull. After the successful cranioplasty surgery and the expected anesthesia recovery period, the pupils of the patients were continued to be dilated and fixed, without light reflection and spontaneous breathing. The Computed Tomography of the patient 1 hour after surgery showed malignant cerebral edema.

CONCLUSIONS

Malignant cerebral edema is a rare and lethal complication after cranioplasty. Negative pressure drainage and deregulation of cerebral blood flow at the end of cranioplasty may partially explain the malignant cerebral after cranioplasty. In addition, patients with epileptic seizures, no spontaneous breathing, dilated pupils without reflection, and hypotension within a short period after cranioplasty may show the occurrence of malignant cerebral.

Dynamic Craniotomy With NuCrani Reversibly Expandable Cranial Bone Flap Fixation Plates: A Technical Report

BACKGROUND

Dynamic craniotomy provides cranial decompression without bone flap removal along with avoidance of cranioplasty and reduced risks for complications.

OBJECTIVE

To report the first clinical cases using a novel dynamic craniotomy bone flap fixation system. The NeuroVention NuCrani reversibly expandable cranial bone flap fixation plates provide dynamic bone flap movement to accommodate changes in intracranial pressure (ICP) after a craniotomy.

METHODS

The reversibly expandable cranial bone flap fixation plates were used for management of cerebral swelling in a patient with a subdural hemorrhage after severe traumatic brain injury and another patient with a hemorrhagic stroke.

RESULTS

Both cases had high ICP's which normalized immediately after the dynamic craniotomy. Progressive postoperative cerebral swelling was noted which was compensated by progressive outward bone flap migration thereby maintaining a normal ICP, and with resolution of the cerebral swelling, the plates retracted the bone flaps to an anatomic flush position.

CONCLUSION

The reversibly expandable plates provide an unhinged cranial bone flap outward migration with an increase in ICP and retract the bone flap after resolution of brain swelling while also preventing the bone flap from sinking inside the skull.

[Surgical treatment of patients with skull defects and cerebrospinal fluid flow disorders after previous decompressive craniectomy]

Decompressive craniectomy (DC) is performed for refractory intracranial hypertension following severe traumatic brain injury, vascular and oncological diseases. This fact increases the number of patients with extensive and giant skull defects. Cerebrospinal fluid (CSF) flow disorders after DC are often accompanied by ventriculomegaly. However, only some patients with ventriculomegaly have hydrocephalus and require CSF bypass procedures. Differentiation of post-traumatic hydrocephalus requiring surgical treatment and atrophic dilation of ventricular system «ex vacuo» caused by brain injury is still an important issue. Skull sealing as a way to normalize CSF circulation and eliminate hydrocephalus is also an open question. Currently, there is no unified approach to patients with extensive and giant cranial defects combined with post-traumatic hydrocephalus. There is no unified algorithm for sequence of reconstructive and CSF bypass operations in these patients. Literature data on risks of infectious complications for different surgical strategies are controversial.

Delayed Postoperative Tension Pneumocephalus Treated With a Subdural Evacuating Port System: A Case Report and Review of the Literature

Tension pneumocephalus (TP) is a rare neurosurgical emergency due to the rise of intracranial pressure from air in the cranial cavity. Tension pneumocephalus' clinical presentation ranges from headache, visual alterations, altered mental status, and death. Given its nonspecific clinical presentation, tension pneumocephalus is usually diagnosed via computed tomography (CT) imaging. Open burr hole craniotomy is the preferred treatment method for tension pneumocephalus. Subdural evacuating port system (SEPS) drains have, however, seen increased utilization in neurosurgery due to decreased possibilities for infections, reduced seizure probability, and better outcomes post-surgery, especially for elderly patients. In this article, we present the case of a 67-year-old female with postoperative tension pneumocephalus after the evacuation of an acute subdural hematoma. The patient became symptomatic from tension pneumocephalus, which was evacuated using a subdural evacuating port system drain. Post-drain placement, the patient had a radiographic and clinical resolution of her tension pneumocephalus. Thesubdural evacuating port system is a useful adjunctive tool for treating tension pneumocephalus.Given the favorable characteristic profile of subdural evacuating port system drains compared to open surgical modalities, further inquiry should be pursued to analyze the feasibility of establishing subdural evacuating port systems as a less invasive treatment alternative.

Predictors of Clinical Outcomes in Autologous Cranioplasty

BACKGROUND

Cranioplasty is a common neurosurgical procedure and autologous grafts are preferred due to their aesthetic and biocompatibility benefits. Multiple risk factors are implicated as predictors for neurologic outcome. This study focuses on risk factors that may be associated with complications and analyzes the predictors of neurologic outcomes after autologous cranioplasty.

METHODS

This is a retrospective observational study conducted at a tertiary care center between 2015 and 2021. Adults with autologous cranioplasty (n = 132) were recruited from procedure logs and the hospital electronic health record. Clinicodemographic parameters, risk factors, and complications were recorded. Neurologic outcomes were measured using the dichotomized Glasgow Outcome Scale (GOS). Primary outcome measure was pre- and post-cranioplasty GOS at the last follow up. Secondary outcome measures were the predicting factors that contributed to enhanced neurologic outcome post-cranioplasty.

RESULTS

Mean age was 41.4 (standard deviation ± 13.5) years with male predominance (12.2:1). Complications developed in 12.9% (n = 17), with infections in 3.8% (n = 5) and hydrocephalus in 2.3% (n = 3). In bivariate analysis, pre-cranioplasty GOS good grades 4 and 5 (P < 0.001), trauma as an indication for decompressive craniectomy (DC) (P < 0.001), and early cranioplasty ≤12 weeks (P = 0.023) were statistically significant predictors for post-cranioplasty neurologic recovery at follow-up. In a multiple logistic regression model, adjusted odds ratio for pre-cranioplasty GOS was 28.77 (95% confidence interval [CI] 7.21-114.74, P < 0.001), for trauma as indication for DC was 5.15 (95% CI 1.65-16.05, P = 0.003), and for early cranioplasty ≤12 weeks was 3.04 (95% CI 1.12-8.27 P = 0.029).

CONCLUSIONS

Autologous cranioplasty contributes to a quantifiable neurologic outcome. Pre-cranioplasty neurologic status, cranioplasty done for traumatic DC and early cranioplasty may have potential for enhanced neurologic recovery. Further clinical studies with better evidence may expound upon these findings.

Prediction of Shunt-Dependent Hydrocephalus after Primary Supratentorial Intracerebral Hemorrhage with a Focus on the Influence of Craniectomies

Objective

Hydrocephalus after intracerebral hemorrhage (ICH) is known to be related to poor prognosis and mortality. We analyzed predictors of permanent hydrocephalus in the patients with surgically treated supratentorial ICH.

Methods

From 2004 to 2019, a total of 414 patients with surgically treated primary supratentorial ICH were included. We retrospectively analyzed age, sex, preexisting hypertension and diabetes, location and volume of ICH, presence and severity of intraventricular hemorrhage (IVH), and type of surgery.

Results

Forty patients (9.7%) required shunt surgery. Concomitant IVH was higher in the 'shunt required' group (92.5%) than in the 'shunt not required' group (67.9%) (p=0.001). IVH severity was worse in the 'shunt required' group (13.5 vs. 7.5, p=0.008). Craniectomy (47.5%) was significantly high in the 'shunt required' group. According to multivariable analysis, the presence of an IVH was 8.1 times more frequent and craniectomy was 8.6 times more frequent in the 'shunt required' group. In the comparison between craniotomy and craniectomy group, the presence of an IVH was related with a 3.9 times higher (p=0.033) possibility and craniectomies rather than craniotomies with a 7-times higher possibility of shunt surgery (p<0.001). Within the craniectomy group, an increase in the craniectomy area by 1 cm2 was correlated with a 3.2% increase in the possibility of shunt surgery (odds ratio, 1.032; 95% confidence interval, 1.005-1.061; p=0.022).

Conclusion

Presence of IVH, the severity of IVH and decompressive craniectomy were related to the development of shunt dependent hydrocephalus in the patients with ICH. The increasing size of craniectomy was related with increasing rate of shunt requirement.

Inflammation and the role of infection: Complications and treatment options following neurotrauma

Traumatic brain injury can have devastating consequences for patients and extended hospital stays and recovery course. Recent data indicate that the initial insult causes profound changes to the immune system and leads to a pro-inflammatory state. This alteration in homeostasis predisposes patients to an increased risk of infection and underlying autoimmune conditions. Increased emphasis has been placed on understanding this process both in the clinical and preclinical literature. This review highlights the intrinsic inflammatory conditions that can occur within the initial hospital stay, discusses long-term immune consequences, highlights emerging treatment options, and delves into important pathways currently being investigated with preclinical models.

3D-printed external cranial protection following decompressive craniectomy after brain injury: A pilot feasibility cohort study

OBJECTIVES

3D-printed (3DP) customized temporary cranial protection solutions following decompressive craniectomy (DC) are currently not widely practiced. A pilot trial of a 3DP customized head protection prototype device (HPPD) on 10 subjects was conducted during the subacute rehabilitation phase.

MATERIALS AND METHODS

Subjects > 30 days post-DC with stable cranial flaps and healed wounds were enrolled. HPPD were uniquely designed based on individuals' CT scan, where the base conformed to the surface of the individual's skin covering the cranial defect, and the lateral surface three-dimensionally mirrored, the contralateral healthy head. Each HPPD was fabricated using the fused deposition modeling method. These HPPD were then fitted on subjects using a progressive wearing schedule and monitored over 1, 2, 4, 6 and 8 follow-up (FU) weeks. Outcomes during FU included; reported wearing time/day (hours), subjective pain, discomfort, pruritus, dislodgment, cosmesis ratings; and observed wound changes. The primary outcome was safety and tolerability without pain or wound changes within 30 minutes of HPPD fitting.

RESULTS

In all, 10 enrolled subjects received 12 HPPDs [5/10 male, mean (SD) age 46 (14) years, mean (SD) duration post-DC 110 days (76)] and all subjects tolerated 30 minutes of initial HPPD fitting without wound changes. The mean (SD) HPPD mass was 61.2 g (SD 19.88). During 8 weeks of FU, no HPPD-related skin dehiscence was observed, while 20% (2/10) had transient skin imprints, and 80% (8/10) reported self-limiting pressure and pruritis.

DISCUSSION

Findings from this exploratory study demonstrated preliminary feasibility and safety for a customized 3DP HPPD for temporary post-DC head protection over 8 weeks of follow-up. Monitoring and regular rest breaks during HPPD wear were important to prevent skin complications.

CONCLUSION

This study suggests the potential for wider 3DP technology applications to provide cranial protection for this vulnerable population.

Decompressive Craniectomy After Traumatic Brain Injury: Incorporating Patient Preferences into Decision-Making

BACKGROUND

Decompressive craniectomy (DC) is highly effective in relieving intracranial hypertension; however, patient selection, intracranial pressure threshold, timing, and long-term functional outcomes are all subject to controversy. Recently, recommendations were made to update the Brain Trauma Foundation guidelines in regards to the use of DC based on the DECRA (Decompressive Craniectomy in Patients with Severe Traumatic Brain Injury) and RESCUEicp (Trial of Decompressive Craniectomy for Traumatic Intracranial Hypertension) clinical trials. Neither the updated recommendations, nor the aforementioned trials, provide a method in incorporating individualized patient or surrogate decision-maker preferences into decision making.

METHODS

In this manuscript, we aimed to redress the gap of not incorporating patient preferences in such value-laden decision making as in the case of DC for refractory post-traumatic intracranial hypertension. We proposed a decision aid based on principles of Decision Theory, and specifically of Expected Utility Theory.

RESULTS

We showed that 1) early secondary DC as studied in DECRA, and based on the 1-year outcome data, is associated with decreased expected utility for all possible preference rankings of outcomes; and 2) recommending a late secondary DC versus tier-3 medical therapy, as studied in RESCUEicp, should be informed by individualized patient preference rankings of outcomes as elicited via shared decision-making.

CONCLUSIONS

The 1-year outcomes from DECRA and RESCUEicp have served as the basis for updated guidelines. However, unaided interpretation of trial data may not be adequate for individualized decision-making; we suggest that the latter can be significantly supported by decision aids such as the one described here and based on expected utility theory.

Syndrome of the trephined: clinical spectrum, risk factors, and impact of cranioplasty on neurologic recovery in a prospective cohort

Syndrome of the trephined (SoT) is an underrecognized complication after decompressive craniectomy. We aimed to investigate SoT incidence, clinical spectrum, risk factors, and the impact of the cranioplasty on neurologic recovery. Patients undergoing a large craniectomy (> 80 cm²) and cranioplasty were prospectively evaluated using modified Rankin score (mRS), cognitive (attention/processing speed, executive function, language, visuospatial), motor (Motricity Index, Jamar dynamometer, postural score, gait assessment), and radiologic evaluation within four days before and after a cranioplasty. The primary outcome was SoT, diagnosed when a neurologic improvement was observed after the cranioplasty. The secondary outcome was a good neurologic outcome (mRS 0–3) 4 days and 90 days after the cranioplasty. Logistic regression models were used to evaluate the risk factors for SoT and the impact of cranioplasty timing on neurologic recovery. We enrolled 40 patients with a large craniectomy; 26 (65%) developed SoT and improved after the cranioplasty. Brain trauma, hemorrhagic lesions, and shifting of brain structures were associated with SoT. After cranioplasty, a shift towards a good outcome was observed within 4 days (p = 0.025) and persisted at 90 days (p = 0.005). Increasing delay to cranioplasty was associated with decreased odds of improvement when adjusting for age and baseline disability (odds ratio 0.96; 95% CI, 0.93–0.99, p = 0.012). In conclusion, SoT is frequent after craniectomy and interferes with neurologic recovery. High suspicion of SoT should be exercised in patients who fail to progress or have a previous trauma, hemorrhage, or shifting of brain structures. Performing the cranioplasty earlier was associated with improved and quantifiable neurologic recovery.

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.

Decreased income, unemployment, and disability after craniotomy for brain tumor removal: a South Korean nationwide cohort study

PURPOSE

We aimed to investigate the prevalence of quality-of-life deterioration and associated factors in patients who underwent craniotomies for brain tumor removal. Additionally, we examined whether deteriorating quality of life after surgery might affect mortality.

METHODS

As a national population-based cohort study, data were extracted from the National Health Insurance Service database of South Korea. Adult patients (≥ 18 years old) who underwent craniotomy for excision of brain tumors after diagnosis of malignant brain tumor between January 1, 2011, and December 31, 2017, were included in this study.

RESULTS

A total of 4852 patients were included in the analysis. Among them, 2273 patients (46.9%) experienced a deterioration in quality of life after surgery. Specifically, 595 (12.3%) lost their jobs, 1329 (27.4%) experienced decreased income, and 844 (17.4%) patients had newly acquired disabilities. In the multivariable Cox regression model, a lower quality of life was associated with a 1.41-fold higher 2-year all-cause mortality (hazard ratio: 1.41, 95% confidence interval: 1.27-1.57; P < 0.001). Specifically, newly acquired disability was associated with 1.80-fold higher 2-year all-cause mortality (hazard ratio: 1.80, 95% confidence interval: 1.59-2.03; P < 0.001), while loss of job (P = 0.353) and decreased income (P = 0.599) were not significantly associated.

CONCLUSIONS

At 1-year follow-up, approximately half the patients who participated in this study experienced a deterioration in the quality-of-life measures of unemployment, decreased income, and newly acquired disability after craniotomy for excision of brain tumors. Newly acquired disability was associated with increased 2-year all-cause mortality.

Factors predicting complications following cranioplasty

This study aimed to identify factors that predict complications following cranioplasty, by conducting a retrospective cohort study at a large tertiary care center. Electronic databases were searched to identify all patients who underwent cranioplasty at our institution. Baseline demographics, perioperative variables, and outcomes were extracted. Logistic regression analyses were conducted to identify factors associated with cranioplasty complications. Of the 92 included patients, 15 (16.3%) experienced one or more complications, with 11 (73.3%) experiencing complication within 30 days of cranioplasty. Patients aged ≤60 had decreased odds of all-cause complication (OR 0.058; 95% CI 0.008-0.434) and cranioplasty graft removal (OR 0.035; 95% CI 0.004-0.321) on multivariate analysis. Titanium mesh cranioplasties were associated with increased odds of all-cause complication (OR 19.776; 95% CI 1.021-382.901), and cranioplasty removal (OR 29.780; 95% CI 1.330-666.878). A longer craniectomy-cranioplasty interval was associated with increased odds of cranioplasty removal (OR 1.005; 95% CI 1.000-1.010). An initial craniectomy indication of cerebral infarction was associated with decreased odds of all-cause complication (OR 0.042; 95% CI 0.002-0.876) and cranioplasty removal (OR 0.032; 95% CI 0.001-0.766). Elderly patients may require more aggressive follow-up and antibiotic prophylaxis in the postoperative period following cranioplasty. Additionally, avoiding the use of titanium mesh cranioplasties and prolonged craniectomy-cranioplasty intervals may further reduce complications.

Contemporary Review on Craniectomy and Cranioplasty; Part 2: Material Selection and Plate Manufacture

ABSTRACT

Cranioplasty materials include metals (ie, titanium); ceramics (ie, hydroxyapatite); polymers (ie, poly-methyl-metha-acrylate [PMMA]); and plastics (ie, polyether ether ketone). This paper aims to review their advantages and drawbacks. No ideal material currently exist, however, titanium implants are universally agreed to have lower infection rates than those reported for hydroxyapatite and PMMA implants; thus justifying their current wide use. These implants can be manufactured conventionally from medical grade titanium alloy Ti64 (titanium-aluminum-vanadium) in the form of plates ranging in thickness from 0.5 to 0.7 mm thick, or following the computer-aided design/manufacture principle. Surface finish of these implants is best achieved by electroplating.

Influence of Decompressive Craniectomy Post Evacuation of Epidural Hematoma in Comatose Patients

BACKGROUND

Epidural hematoma causing brain herniation is a major cause of mortality and morbidity after severe traumatic brain injury, even if surgical treatment is performed quickly. Decompression may be effective in decreasing intracranial pressure, but its effect on outcomes remains unclear.

METHODS

A retrospective analysis of deeply comatose patients (Glasgow Coma Scale score 3-5) who underwent surgical treatment during a 12-year period, either via osteoplastic craniotomy (OC) or decompressive craniectomy, was carried out. Patient groups were compared on the basis of demographics, admission clinical state, head computed tomography imaging characteristics, and discharge outcome.

RESULTS

A total of 60 patients were examined. The first group of 31 patients (52%) needed decompression during primary surgery. The second group of 29 patients (48%) underwent OC with evacuation of epidural hematoma without decompression. Both patient groups were similar according to age (40.9 ± 13 vs. 40.6 ± 12.5 years), Glasgow Coma Scale score before surgery (4 [3-5] vs. 4 [3-5]), hematoma thickness (based on computed tomography) (3.44 ± 1 vs. 3.36 ± 1.62 cm), and midline shift (1.42 ± 0.83 vs. 1.36 ± 0.9 cm). Mortality was more evident in the decompression group (45.2% vs. 13.8%; P = 0.008), and the Glasgow Outcome Score was also lower, 2.26 ± 1.5 versus 3.45 ± 1.5 (P = 0.003).

CONCLUSIONS

Decompressive craniectomy following the evacuation of an acute epidural hematoma in deeply comatose patients demonstrated inferior outcomes in comparison with OC. Brain injury in the decompressive craniectomy patient group was more severe (concomitant subdural hematoma, early brain ischemia, and early brain herniation), which may have influenced the outcome. Further prospective studies are needed.

Scenario for the use of effusion-peritoneal shunt necessary against subdural effusion secondary to decompressive craniectomy

OBJECTIVES

This study aimed to summarize the surgical strategies for subdural effusion secondary to decompressive craniectomy (SESDC) and discuss the applicable scenarios of effusion-peritoneal shunt (EP shunt).

METHODS

A total of 53 consecutive patients with SESDC were screened out of 7569 cases. The SESDC was divided into five types, and the treatment methods of each type were analyzed and compared. According to the implementation strategy of cranioplasty (CP), patients were divided into CP-first and delayed-CP groups. The differences in surgical methods were compared between the two groups.

RESULTS

All patients with SESDC in this cohort had undergone cranioplasty. Subcutaneous puncture and aspiration (SPAA) proved ineffective. Only 2/30 patients in the CP-first group used EP shunt, while 6/19 patients in the delayed-CP group used EP shunt; the difference was statistically significant (P = 0.03). A significant difference was found in the use of EP shunt among type 1, type 2, and type 5 SESDC (χ² = 6.778, P = 0.034).

CONCLUSIONS

CP combined with other treatments could cure most SESDC. EP shunt should be used preferentially in some specific scenarios in which CP cannot be performed first, rather than as a backup measure that can only be used when other preceding treatments fail.

Complications of cranioplasty in relationship to traumatic brain injury: a systematic review and meta-analysis

Despite being a common procedure, cranioplasty (CP) is associated with a variety of serious, at times lethal, complications. This study explored the relationship between the initial injury leading to decompressive craniectomy (DC) and the rates and types of complications after subsequent CP. It specifically compared between traumatic brain injury (TBI) patients and patients undergoing CP after DC for other indications.A comprehensive search of PubMed, Scopus, and the Cochrane Library databases using PRISMA guidelines was performed to include case-control studies, cohorts, and clinical trials reporting complication data for CP after DC. Information about the patients' characteristics and the rates of overall and specific complications in TBI and non-TBI patients was extracted, summarized, and analyzed.A total of 59 studies, including the authors' institutional experience, encompassing 9264 patients (4671 TBI vs. 4593 non-TBI) met the inclusion criteria; this total also included 149 cases from our institutional series. The results of the analysis of the published series are shown both with and without our series 23 studies reported overall complications, 40 reported infections, 10 reported new-onset seizures, 13 reported bone flap resorption (BFR), 5 reported post-CP hydrocephalus, 10 reported intracranial hemorrhage (ICH), and 8 reported extra-axial fluid collections (EFC). TBI was associated with increased odds of BFR (odds ratio [OR] 1.76, p < 0.01) and infection (OR 1.38, p = 0.02). No difference was detected in the odds of overall complications, seizures, hydrocephalus, ICH, or EFC.Awareness of increased risks of BFR and infection after CP in TBI patients promotes the implementation of new strategies to prevent these complications especially in this category of patients.

Cranioplasty Using Customized 3-Dimensional-Printed Titanium Implants: An International Collaboration Effort to Improve Neurosurgical Care

BACKGROUND

Evolutions in cranioplasty have allowed for the creation of customized implants via advances in 3-dimensional (3D) printing technology, although the high cost associated with this technique presents a barrier for low-income countries. Through an international collaboration, our team in Da Nang, Vietnam is able to create low-cost, customized titanium implants for patients with skull defects. We discuss the details of our collaboration and present our experience with this procedure.

METHODS

We conducted a retrospective review of 35 patients who underwent cranioplasty using custom-made titanium implants. The molding and implant making processes were performed by our neurosurgeons using a 3D printer donated by the United Kingdom-based nongovernmental organization Facing the World. We obtained demographic and preoperative data (reason for skull defect, location, surface area measurement of defect) and postoperative data (complications, cosmetic outcome, and patient satisfaction).

RESULTS

The median patient age was 27 years (range, 16-60 years). Primary indications for craniectomy included traumatic brain injury from motor vehicle accident (77.1%), cerebrovascular disease (11.4%), implant failure following previous cranioplasty (5.7%), and fall (5.7%). Postoperatively, all implants were found to have an excellent fit; at 6-month follow-up, none of the implants required removal. Complications included 4 postoperative hematomas and 1 surgical site infection. All the patients had improved aesthetic appearance and high satisfaction.

CONCLUSIONS

Cranioplasty using customized titanium implants yields excellent results for patients with skull defects, demonstrating the practicality of this technique for cranioplasty in low-income countries. Our experience highlights the importance of ongoing international collaboration to improve neurosurgical care in these countries.

Complications Following Decompressive Craniectomy

BACKGROUND

 Decompressive craniectomy (DC) has become the definitive surgical procedure to manage a medically intractable rise in intracranial pressure. DC is a life-saving procedure resulting in lower mortality but also higher rates of severe disability. Although technically straightforward, DC is accompanied by many complications. It has been reported that complications are associated with worse outcome. We reviewed a series of patients who underwent DC at our department to establish the incidence and types of complications.

METHODS

 We retrospectively evaluated the incidence of complications after DC performed in 135 patients during the time period from January 2013 to December 2018. Postoperative complications were evaluated using clinical status and CT during 6 months of follow-up. In addition, the impact of potential risk factors on the incidence of complications and the impact of complications on outcome were assessed.

RESULTS

 DC was performed in 135 patients, 93 of these for trauma, 22 for subarachnoid hemorrhage, 13 for malignant middle cerebral artery infarction, and 7 for intracerebral hemorrhage. Primary DC was performed in 120 patients and secondary DC in 15 patients. At least 1 complication occurred in each of 100 patients (74%), of which 22 patients (22%) were treated surgically. The following complications were found: edema or hematoma of the temporal muscle (34 times), extracerebral hematoma (33 times), extra-axial fluid collection (31 times), hemorrhagic progression of contusions (19 times), hydrocephalus (12 times), intraoperative malignant brain edema (10 times), temporal muscle atrophy (7 times), significant intraoperative blood loss (6 times), epileptic seizures (5 times), and skin necrosis (4 times). Trauma (p = 0.0006), coagulopathy (p = 0.0099), and primary DC (p = 0.0252) were identified as risk factors for complications. There was no significant impact of complications on outcome.

CONCLUSIONS

 The incidence of complications following DC is high. However, we did not confirm a significant impact of complications on outcome. We emphasize that some phenomena are so frequent that they can be considered a consequence of primary injury or natural sequelae of the DC rather than its direct complication.

Immunopathogenesis of Craniotomy Infection and Niche-Specific Immune Responses to Biofilm

Bacterial infections in the central nervous system (CNS) can be life threatening and often impair neurological function. Biofilm infection is a complication following craniotomy, a neurosurgical procedure that involves the removal and replacement of a skull fragment (bone flap) to access the brain for surgical intervention. The incidence of infection following craniotomy ranges from 1% to 3% with approximately half caused by Staphylococcus aureus (S. aureus). These infections present a significant therapeutic challenge due to the antibiotic tolerance of biofilm and unique immune properties of the CNS. Previous studies have revealed a critical role for innate immune responses during S. aureus craniotomy infection. Experiments using knockout mouse models have highlighted the importance of the pattern recognition receptor Toll-like receptor 2 (TLR2) and its adaptor protein MyD88 for preventing S. aureus outgrowth during craniotomy biofilm infection. However, neither molecule affected bacterial burden in a mouse model of S. aureus brain abscess highlighting the distinctions between immune regulation of biofilm vs. planktonic infection in the CNS. Furthermore, the immune responses elicited during S. aureus craniotomy infection are distinct from biofilm infection in the periphery, emphasizing the critical role for niche-specific factors in dictating S. aureus biofilm-leukocyte crosstalk. In this review, we discuss the current knowledge concerning innate immunity to S. aureus craniotomy biofilm infection, compare this to S. aureus biofilm infection in the periphery, and discuss the importance of anatomical location in dictating how biofilm influences inflammatory responses and its impact on bacterial clearance.

Consensus statement from the international consensus meeting on post-traumatic cranioplasty

Background

Due to the lack of high-quality evidence which has hindered the development of evidence-based guidelines, there is a need to provide general guidance on cranioplasty (CP) following traumatic brain injury (TBI), as well as identify areas of ongoing uncertainty via a consensus-based approach.

Methods

The international consensus meeting on post-traumatic CP was held during the International Conference on Recent Advances in Neurotraumatology (ICRAN), in Naples, Italy, in June 2018. This meeting was endorsed by the Neurotrauma Committee of the World Federation of Neurosurgical Societies (WFNS), the NIHR Global Health Research Group on Neurotrauma, and several other neurotrauma organizations. Discussions and voting were organized around 5 pre-specified themes: (1) indications and technique, (2) materials, (3) timing, (4) hydrocephalus, and (5) paediatric CP.

Results

The participants discussed published evidence on each topic and proposed consensus statements, which were subject to ratification using anonymous real-time voting. Statements required an agreement threshold of more than 70% for inclusion in the final recommendations.

Conclusions

This document is the first set of practical consensus-based clinical recommendations on post-traumatic CP, focusing on timing, materials, complications, and surgical procedures. Future research directions are also presented.

Incidence of post-traumatic hydrocephalus in traumatic brain injury patients that underwent DC versus those that were managed without DC: A systematic review and meta-analysis

Introduction

There is an ongoing debate whether Decompressive Craniectomy (DC) serves as an independent risk factor for the development of Post-traumatic Hydrocephalus (PTH).

Research question

The aim of this systematic review and meta-analysis was to compare the incidence of PTH in TBI patients that underwent DC versus those that were managed without DC.

Materials and methods

The literature was systematically reviewed to identify studies with specific inclusion criteria: (1) Randomized Controlled Trials and observational studies with more than 10 patients in each study arm, (2) comparing the incidence of PTH, (3) in patients aged ≥15 years old, (4) that either underwent DC or received other treatment (non-DC). (5) Only studies in English were included and (6) no restrictions were applied on publication date. The pooled Odds Ratio (OR) and Confidence Interval (CI) were calculated. The quality of the included studies was assessed using the ROBINS and RoB 2.0 tools.

Results

Evidence from six articles was synthesized, incorporating data from 2522 patients. A statistically significant higher occurrence of PTH [OR (95% CI): 4.84 (2.51, 9.31); Pz ​< ​0.00001] was identified in patients undergoing DC for TBI when compared to those that were managed without DC. The same was true when only patients with severe TBI were included in the analysis [OR (95% CI): 2.87 (1.85, 4.43); Pz ​< ​0.00001].

Discussion and conclusion

Our study has shown, within limitations, a clear association between DC and PTH. Further prospective studies, providing high-quality evidence, are needed to definitively establish any causative relationship between DC and PTH.

•

TBIs are associated with the development of PTH.

•

Patients undergoing decompressive craniectomy are more likely to develop PTH.

•

Further studies should be conducted to establish a causative relationship.

Is Spreading Depolarization a Risk Factor for Late Epilepsy? A Prospective Study in Patients with Traumatic Brain Injury and Malignant Ischemic Stroke Undergoing Decompressive Craniectomy

OBJECTIVE

Spreading depolarizations (SDs) have been described in patients with ischemic and haemorrhagic stroke, traumatic brain injury, and migraine with aura, among other conditions. The exact pathophysiological mechanism of SDs is not yet fully established. Our aim in this study was to evaluate the relationship between the electrocorticography (ECoG) findings of SDs and/or epileptiform activity and subsequent epilepsy and electroclinical outcome.

METHODS

This was a prospective observational study of 39 adults, 17 with malignant middle cerebral artery infarction (MMCAI) and 22 with traumatic brain injury, who underwent decompressive craniectomy and multimodal neuromonitoring including ECoG in penumbral tissue. Serial electroencephalography (EEG) recordings were obtained for all surviving patients. Functional disability at 6 and 12 months after injury were assessed using the Barthel, modified Rankin (mRS), and Extended Glasgow Outcome (GOS-E) scales.

RESULTS

SDs were recorded in 58.9% of patients, being more common-particularly those of isoelectric type-in patients with MMCAI (p < 0.04). At follow-up, 74.7% of patients had epileptiform abnormalities on EEG and/or seizures. A significant correlation was observed between the degree of preserved brain activity on EEG and disability severity (R [mRS]: + 0.7, R [GOS-E, Barthel]: - 0.6, p < 0.001), and between the presence of multifocal epileptiform abnormalities on EEG and more severe disability on the GOS-E at 6 months (R: - 0.3, p = 0.03) and 12 months (R: - 0.3, p = 0.05). Patients with more SDs and higher depression ratios scored worse on the GOS-E (R: - 0.4 at 6 and 12 months) and Barthel (R: - 0.4 at 6 and 12 months) disability scales (p < 0.05). The number of SDs (p = 0.064) and the depression ratio (p = 0.1) on ECoG did not show a statistically significant correlation with late epilepsy.

CONCLUSIONS

SDs are common in the cortex of ischemic or traumatic penumbra. Our study suggests an association between the presence of SDs in the acute phase and worse long-term outcome, although no association with subsequent epilepsy was found. More comprehensive studies, involving ECoG and EEG could help determine their association with epileptogenesis.

Deciding Under Uncertainty: The Case of Refractory Intracranial Hypertension

A challenging clinical conundrum arises in severe traumatic brain injury patients who develop intractable intracranial hypertension. For these patients, high morbidity interventions such as surgical decompression and barbiturate coma have to be considered against a backdrop of uncertain outcomes including prolonged states of disordered consciousness and severe disability. The clinical evidence available to guide shared decision-making is mainly limited to one randomized controlled trial, the RESCUEicp. However, since the publication of this trial significant controversy has been ongoing over the interpretation of the results. Is the mortality benefit from surgery merely a trade off for unacceptable long-term disability? How should treatment options, possible outcomes, and results from the trial be communicated to surrogates? How do we incorporate patient values into forming plans of care? The aim of this article is to sketch an approach based on insights from Decision Theory, and specifically deciding under uncertainty. The mainstream normative decision theory, Expected Utility (EU) theory, essentially says that, in situations of uncertainty, one should prefer the option with greatest expected desirability or value. The steps required to compute expected utilities include listing the possible outcomes of available interventions, assigning each outcome a utility ranking representing an individual patient's preferences, and a conditional probability given each intervention. This is a conceptual framework meant to supplement, and enhance shared decision making by assuring that patient values are elicited and incorporated, the possible range and nature of outcomes is discussed, and finally by attempting to connect best available means to patient-individualized ends.

First-In-Human Experience With Integration of Wireless Intracranial Pressure Monitoring Device Within a Customized Cranial Implant

BACKGROUND

Decompressive craniectomy is a lifesaving treatment for intractable intracranial hypertension. For patients who survive, a second surgery for cranial reconstruction (cranioplasty) is required. The effect of cranioplasty on intracranial pressure (ICP) is unknown.

OBJECTIVE

To integrate the recently Food and Drug Administration-approved, fully implantable, noninvasive ICP sensor within a customized cranial implant (CCI) for postoperative monitoring in patients at high risk for intracranial hypertension.

METHODS

A 16-yr-old female presented for cranioplasty 4-mo after decompressive hemicraniectomy for craniocerebral gunshot wound. Given the persistent transcranial herniation with concomitant subdural hygroma, there was concern for intracranial hypertension following cranioplasty. Thus, cranial reconstruction was performed utilizing a CCI with an integrated wireless ICP sensor, and noninvasive postoperative monitoring was performed.

RESULTS

Intermittent ICP measurements were obtained twice daily using a wireless, handheld monitor. The ICP ranged from 2 to 10 mmHg in the supine position and from -5 to 4 mmHg in the sitting position. Interestingly, an average of 7 mmHg difference was consistently noted between the sitting and supine measurements.

CONCLUSION

This first-in-human experience demonstrates several notable findings, including (1) newfound safety and efficacy of integrating a wireless ICP sensor within a CCI for perioperative neuromonitoring; (2) proven restoration of normal ICP postcranioplasty despite severe preoperative transcranial herniation; and (3) proven restoration of postural ICP adaptations following cranioplasty. To the best of our knowledge, this is the first case demonstrating these intriguing findings with the potential to fundamentally alter the paradigm of cranial reconstruction.

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.

When the air hits your brain: decreased arterial pulsatility after craniectomy leading to impaired glymphatic flow

OBJECTIVE

Cranial neurosurgical procedures can cause changes in brain function. There are many potential explanations, but the effect of simply opening the skull has not been addressed, except for research into syndrome of the trephined. The glymphatic circulation, by which CSF and interstitial fluid circulate through periarterial spaces, brain parenchyma, and perivenous spaces, depends on arterial pulsations to provide the driving force for bulk flow; opening the cranial cavity could dampen this force. The authors hypothesized that a craniectomy, without any other pathological insult, is sufficient to alter brain function due to reduced arterial pulsatility and decreased glymphatic flow. Furthermore, they postulated that glymphatic impairment would produce activation of astrocytes and microglia; with the reestablishment of a closed cranial compartment, the glymphatic impairment, astrocytic/microglial activation, and neurobehavioral decline caused by opening the cranial compartment might be reversed.

METHODS

Using two-photon in vivo microscopy, the pulsatility index of cortical vessels was quantified through a thinned murine skull and then again after craniectomy. Glymphatic influx was determined with ex vivo fluorescence microscopy of mice 0, 14, 28, and 56 days following craniectomy or cranioplasty; brain sections were immunohistochemically labeled for GFAP and CD68. Motor and cognitive performance was quantified with rotarod and novel object recognition tests at baseline and 14, 21, and 28 days following craniectomy or cranioplasty.

RESULTS

Penetrating arterial pulsatility decreased significantly and bilaterally following unilateral craniectomy, producing immediate and chronic impairment of glymphatic CSF influx in the ipsilateral and contralateral brain parenchyma. Craniectomy-related glymphatic dysfunction was associated with an astrocytic and microglial inflammatory response, as well as with the development of motor and cognitive deficits. Recovery of glymphatic flow preceded reduced gliosis and return of normal neurological function, and cranioplasty accelerated this recovery.

CONCLUSIONS

Craniectomy causes glymphatic dysfunction, gliosis, and changes in neurological function in this murine model of syndrome of the trephined.

Early cranioplasty associated with a lower rate of post-traumatic hydrocephalus after decompressive craniectomy for traumatic brain injury

BACKGROUND

Post-traumatic hydrocephalus (PTH) is one of the primary complications during the course of traumatic brain injury (TBI). The aim of this study was to define factors associated with the development of PTH in patients who underwent unilateral decompressive craniectomy (DC) for TBI.

METHODS

A total of 126 patients, who met the inclusion criteria of the study, were divided into two groups: patients with PTH (n = 25) and patients without PTH (n = 101). Their demographic, clinical, radiological, operative, and postoperative factors, which may be associated with the development of PTH, were compared.

RESULTS

Multivariate logistic regression analysis revealed that cranioplasty performed later than 2 months following DC was significantly associated with the requirement for ventriculoperitoneal shunting due to PTH (p < 0.001). Also, a significant unfavorable outcome rate was observed in patients with PTH at 1-year follow-up according to the Glasgow Outcome Scale-Extended (p = 0.047).

CONCLUSIONS

Our results show that early cranioplasty within 2 months after DC was associated with a lower rate of PTH development after TBI.

Cranioplasty: A Comprehensive Review of the History, Materials, Surgical Aspects, and Complications

Cranioplasty is a common neurosurgical procedure performed to reconstruct cranial defects. The materials used to replace bone defects have evolved throughout history. Cranioplasty materials can be broadly divided into biological and synthetic materials. Biological materials can be further subdivided into autologous grafts, allografts, and xenografts. Allografts (bony materials and cartilage from cadavers) and xenografts (bony materials from animals) are out of favor for use in cranioplasty because of their high rates of infection, resorption, and rejection. In autologous cranioplasty, either the cranial bone itself or bones from other parts of the body of the patient are used. Synthetic bone grafts have reduced the operation time and led to better cosmetic results because of the advancement of computer-based customization and three-dimensional printing. Aluminum was the first synthetic bone graft material used, but it was found to irritate neural tissue, induce seizures, and dissolve over time. Acrylic, in the form of methyl methacrylate, is the most widely used material in cranioplasty. Hydroxyapatite is a natural component of bone and is believed to enhance bone repair, resulting in decreased tissue reactions and promoting good osteointegration. Polyetheretherketones are light and nonconductive and do not interfere with imaging modalities. The complication rates of cranioplasty are high, and surgical site infection is the most common complication. The effect of cranioplasty timing on cognitive function remains debatable. However, the timing of cranioplasty is independent of neurologic outcomes. In this article, the history, materials, complications, and evolution of current practices used in cranioplasty are comprehensively reviewed.

Factors associated with the development and outcome of hydrocephalus after decompressive craniectomy for traumatic brain injury

Posttraumatic hydrocephalus (PTH) is common in patients undergoing decompressive craniectomy (DC) for traumatic brain injury (TBI), but the incidence, mechanisms, and risk factors have not been fully elucidated. This study aimed to determine the incidence of and the factors associated with PTH. We retrospectively reviewed patients who underwent DC for TBI at our institute between January 2014 and December 2018. We identified and compared the demographic, clinical, and radiological data, and 12-month functional outcome (as assessed by the Glasgow Outcome Scale [GOS]) between patients who developed PTH and those who did not. Logistic regression analyses were performed to identify risk factors for PTH. Additionally, the influence of PTH on unfavorable functional outcome was analyzed. PTH developed in 18 (18.95%) of the 95 patients who survived at 1 month after DC. A multivariate analysis indicated that postoperative intraventricular hemorrhage (odds ratio [OR] 4.493, P = 0.020), postoperative subdural hygroma (OR 4.074, P = 0.021), and postoperative hypothermia treatment (OR 9.705, P = 0.010) were significantly associated with PTH. The 12-month functional outcome significantly differed between the patients who developed PTH and those who did not (P = 0.049). Patients who developed PTH had significantly poorer 12-month functional outcomes than those who did not (P = 0.049). Another multivariate analysis indicated that subdural hemorrhage (OR 6.814, P = 0.031) and the presence of at least one dilated pupil before DC (OR 8.202, P = 0.000) were significantly associated with unfavorable functional outcomes (GOS grades 1-3). Although the influence of PTH (OR 5.122, P = 0.056) was not statistically significant in the multivariate analysis, it had a great impact on unfavorable functional outcomes. PTH considerably affects functional outcomes at 12 months after DC for TBI. Furthermore, postoperative imaging findings such as intraventricular hemorrhage and subdural hygroma can predict the development of PTH; therefore, careful observation is required during the follow-up period.

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.

Comparison between the different types of heterologous materials used in cranioplasty: a systematic review of the literature

INTRODUCTION

The choice of heterologous materials for cranioplasty after decompressive craniectomy is still difficult. The aim of this study is to examine the association between material of choice and related complications to suggest the best treatment option.

EVIDENCE ACQUISITION

A systematic review was performed for articles reporting cranioplasty comparing the following heterologous implants: titanium, poli-methyl-methacrylate (PMMA), polyetheretherketone (PEEK) and hydroxyapatite (HA). Extracted data included implant materials and incidence of the most frequent complications.

EVIDENCE SYNTHESIS

The final selection resulted in 106 papers but according to our rules only 27 studies were included in the final analysis. Among a total of 1688 custom-made prosthesis implanted, 649 were titanium (38.49%), 298 PMMA (17.56%), 233 PEEK (13.82%), and 508 were HA (30.13%). A total of 348 complications were recorded out of 1688 reported patients (20.64%). In the titanium group, 139 complications were recorded (21.42%); in the PMMA group 57 (19.26%), in the PEEK group 49 (21.03%) and in the HA group 103 (20.3%). If we examine a summary of the reported complications clearly related to cranioplasty (postoperative infections, fractures and prosthesis displacement) versus type of material in multicentric and prospective studies we can see how HA group patients have less reported infections and cranioplasty explantation after infections than PMMA, PEEK and titanium. On the contrary HA patients seem to have a higher number of prosthesis displacement again if compared with the other materials. Since these data are not derived from a statistically correct analysis they should be used only to help to differentiate the properties of the various heterologous cranioplasties.

CONCLUSIONS

The ideal material for all heterologous cranioplasty has not yet been identified. The choice of material should be based on the clinical data of patients, such as the craniectomy size, presence of seizures, possibility of recovery, good long-term outcome associated with a cost analysis.