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Complications of cranioplasty following decompressive craniectomy for traumatic brain injury: systematic review and meta-analysis

Authors:
Jack Henry at Royal College of Surgeons in Ireland
Jack Henry
Michael Amoo at Royal College of Surgeons in Ireland
Michael Amoo
Adam Murphy
Adam Murphy
Adam Murphy
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David P. O’Brien
David P. O’Brien
David P. O’Brien
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Background Decompressive craniectomy (DC) is a common neurosurgical intervention for severe traumatic brain injury (TBI), as well as malignant stroke, malignancy and infection. DC necessitates subsequent cranioplasty. There are significant demographic differences between TBI and non-TBI patients undergoing cranioplasty, which may influence their relative risk profiles for infection, aseptic bone flap resorption (aBFR) and re-operation. Objective Perform a meta-analysis to determine the relative infection, aBFR and re-operation risk profiles of TBI patients as compared to other indications for DC. Methods A systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. PubMed, MEDLINE, EMBASE and Google Scholar were searched until 26/11/2020. Studies detailing rates of infection, re-operation and/or aBFR in specific materials and the post-TBI population were included, while studies in paediatrics or craniosynostosis repair were excluded. Results Twenty-six studies were included. There was no difference in relative risk of infection between TBI and non-TBI cohorts (RR 0.81, 95% CI 0.57–1.17), with insignificant heterogeneity (I2 = 33%). TBI was a risk factor for aBFR (RR 1.54, 95% CI 1.25–1.89), with no significant heterogeneity (I2 = 13%). TBI was a risk factor for re-operation in the autologous sub-group (RR 1.49, 95% CI 1.05–2.11) but not in the alloplastic sub-group (RR = 0.86, 95% CI 0.34–2.18). Heterogeneity was insignificant (I2 = 11%). Conclusion TBI is a risk factor for aBFR and re-operation following cranioplasty. Use of an alloplastic graft for primary cranioplasty in these patients may partially mitigate this increased risk.
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REVIEW ARTICLE - BRAIN TRAUMA
Complications of cranioplasty following decompressive craniectomy
for traumatic brain injury: systematic review and meta-analysis
Jack Henry
1,2
&Michael Amoo
1,3
&Adam Murphy
1
&David P. O’Brien
1,3
Received: 30 January 2021 /Accepted: 10 March 2021
#The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature 2021
Abstract
Background Decompressive craniectomy (DC) is a common neurosurgical intervention for severe traumatic brain injury (TBI),
as well as malignant stroke, malignancy and infection. DC necessitates subsequent cranioplasty. There are significant demo-
graphic differences between TBI and non-TBI patients undergoing cranioplasty, which may influence their relative risk profiles
for infection, aseptic bone flap resorption (aBFR) and re-operation.
Objective Perform a meta-analysis to determine the relative infection, aBFR and re-operation risk profiles of TBI patients as
compared to other indications for DC.
Methods A systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. PubMed,
MEDLINE, EMBASE and Google Scholar were searched until 26/11/2020. Studies detailing rates of infection, re-operation
and/or aBFR in specific materials and the post-TBI population were included, while studies in paediatrics or craniosynostosis
repair were excluded.
Results Twenty-six studies were included. There was no difference in relative risk of infection between TBI and non-TBI cohorts
(RR 0.81, 95% CI 0.57–1.17), with insignificant heterogeneity (I
2
= 33%). TBI was a risk factor for aBFR (RR 1.54, 95% CI
1.25–1.89), with no significant heterogeneity (I
2
= 13%). TBI was a risk factor for re-operation in the autologous sub-group (RR
1.49, 95% CI 1.05–2.11) but not in the alloplastic sub-group (RR= 0.86, 95% CI 0.34–2.18). Heterogeneity was insignificant (I
2
=11%).
Conclusion TBI is a risk factor for aBFR and re-operation following cranioplasty. Use of an alloplastic graft for primary
cranioplasty in these patients may partially mitigate this increased risk.
Keywords Cranioplasty .Decompressive craniectomy .Traumatic brain injury .Aseptic bone flap resorption
Introduction
Traumatic brain injury (TBI) is an important cause of morbid-
ity and mortality worldwide. In the UK, it is the leading cause
of death and disability in people under 40 years old [55]. It
accounts for an estimated 37% of all injury-related death in the
EU and 30.5% in the USA [44]. Severe TBI often requires
surgical intervention. Recently, a large randomised trial has
demonstrated the efficacy of decompressive craniectomy
(DC) in reducing mortality in refractory intracranial hyperten-
sion [30]. With an increase in prevalence of DC along with
improving survival in TBI [44], much focus has recently been
placed on its sequelae and rehabilitation. Cranioplasty restores
the normal calvarial morphology and provides protection for
the underlying brain fromfurther traumatic insult. Its addition-
al benefits include normalising of cerebrospinal fluid [18]and
blood flow [22] dynamics, improvement of neurological func-
tion [27] and prevention of syndrome of the trephined [5].
This potential improvement in neurological function carries
promise in optimising rehabilitation. However, high compli-
cation rates of 7.8–66.9%havebeenreported[36,40,42,79,
This article is part of the Topical Collection on Brain trauma
Presentation at a conference
The abstract will be presented in Dundee April 14–16th, 2021, at the
Society of British Neurosurgeons Annual Spring Meeting.
*Jack Henry
jack.henry@ucdconnect.ie
1
National Centre for Neurosurgery, Beaumont Hospital,
Dublin, Ireland
2
School of Medicine, University College Dublin, Dublin, Ireland
3
Royal College of Surgeons Ireland, Dublin, Ireland
https://doi.org/10.1007/s00701-021-04809-z
/ Published online: 23 March 2021
Acta Neurochirurgica (2021) 163:1423–1435
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... DC is associated with more intracranial complications than craniotomy [18]. Moreover, DC requires cranioplasty (CP) later, and CP also has a high rate of complications such as infection and bone flap resorption [3]. Hematoma removal in patients with ASDH is necessary as a lifesaving measure when intracranial pressure is highly elevated, but whether DC or craniotomy is more appropriate remains unclear. ...
... DC is associated with complications such as subdural hygroma, infection, expansion of contusions, new contralateral hematoma, extracranial herniation, hydrocephalus, and bone flap resorption [13]. DC requires CP later, and CP also has complications such as infection, bone flap resorption, seizure, and postoperative hematoma [2,3]. DC is also associated with more follow-on surgeries, intracranial complications, and higher likelihood of requiring shunts compared to CC [18]. ...
Effectiveness of hinge craniotomy as an alternative to decompressive craniectomy for acute subdural hematoma
Article
Full-text available
  • Jun 2024
  • ACTA NEUROCHIR
Background Acute subdural hematoma (ASDH) is a life-threatening condition, and hematoma removal is necessary as a lifesaving procedure when the intracranial pressure is highly elevated. However, whether decompressive craniectomy (DC) or conventional craniotomy (CC) is adequate remains unclear. Hinge craniotomy (HC) is a technique that provides expansion potential for decompression while retaining the bone flap. At our institution, HC is the first-line operation instead of DC for traumatic ASDH, and we present the surgical outcomes. Methods From January 1, 2017, to December 31, 2022, 372 patients with traumatic ASDH were admitted to our institution, among whom 48 underwent hematoma evacuation during the acute phase. HC was performed in cases where brain swelling was observed intraoperatively. If brain swelling was not observed, CC was selected. DC was performed only when the brain was too swollen to allow replacement of the bone flap. We conducted a retrospective analysis of patient demographics, prognosis, and subsequent cranial procedures for each technique. Results Of the 48 patients, 2 underwent DC, 23 underwent HC, and 23 underwent CC. The overall mortality rate was 20.8% (10/48) at discharge and 30.0% (12/40) at 6 months. The in-hospital mortality rates for DC, HC, and CC were 100% (2/2), 21.7% (5/23), and 13.0% (3/23), respectively. Primary brain injury was the cause of death in five patients whose brainstem function was lost immediately after surgery. No fatalities were attributed to the progression of postoperative brain herniation. In only one case, the cerebral contusion worsened after the initial surgery, leading to brain herniation and necessitating secondary DC. Conclusions The strategy of performing HC as the first-line operation for ASDH did not increase the mortality rate compared with past surgical reports and required secondary DC in only one case.
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... Free flap transplantation and cranioplasty can be complex surgical measures in patients with scalp and skull defects due to massive scalp tumour resection [13,14] . Postoperative complications such as surgical site infection, scalp flap atrophy and titanium mesh exposure often occur [15,16] . The main reasons for these complications are: (1) postoperative titanium mesh will exert stress on the transplanted skin flap, thereby affecting the local blood supply of the skin flap, resulting in poor healing of the suture [17] ; (2) because the titanium mesh is much thinner than the normal skull, dead space is easily formed after reconstruction, and the muscle and fat carried by the flap are difficult to fill [18] ; (3) In the first-stage scalp and skull reconstruction, the attachment and growth of the skin flap is hindered because the free skin flap is directly covered on the titanium mesh without the blood supply and nutritional support of the skull; (4) Some studies put forward the hypothesis of the mechanism of pressure gradient fluctuation: After cranioplasty, the intracranial pressure fluctuation becomes larger, and the tissue around the mesh becomes thinner due to repeated pressure on the titanium mesh and the lower layer [15,19] . ...
Treatment of hard-to-heal wound after huge scalp tumor resection and reconstruction: a case report
Article
Full-text available
  • Sep 2023
Introduction and importance Free skin flap transplantation and titanium mesh reconstruction can effectively repair the scalp and skull defects caused by massive scalp tumour resection. Postoperative flap infection is a common complication. Due to the presence of titanium mesh, once infection occurs, a second operation is required to remove the titanium mesh, which brings a great physical and economic burden to the patient. Case presentation In this case of postoperative infection, the authors used a conservative treatment based on dressing change, preserved the titanium mesh and flap, avoided secondary surgery, and successfully controlled the infection. Clinical discussion The treatment strategy is mainly divided into three steps: the first stage is to control infection, the authors use complexed iodine to repeatedly disinfect wounds, subcutaneous dead space, exposed titanium mesh, and antibiotic treatment for bacterial culture results; the second stage is to promote granulation growth, After infection control, the authors remove old granulation after each wound disinfection, and then instill fibroblast growth factor to promote subcutaneous granulation growth to fill dead space, and also provide a base platform for epidermal growth; the third stage is mainly epidermal healing, Change the dressing every day to observe the growth of the epidermis. Conclusion This case suggests that conservative treatment strategy based on dressing change is also a potential treatment option for postoperative infection of the flap with exposure of the titanium plate.
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... Complications may occur by several factors, but skull replacement does not increase the risk. [13][14][15][16][17] . To prevent surgical complications, general principles should be followed. ...
Custom-made 3D printing-based cranioplasty using a silicone mould and PMMA
Article
Full-text available
  • Jul 2023
All types of cranioplasty techniques restore the morphology of the skull and affect patient aesthetics. Safe and easy techniques are required to enhance patients’ recovery and the rehabilitation process. We propose a new method of cranioplasty. The 3-dimensional (3D) reconstruction of a thin-layer computed tomography (CT) scan of the skull was used to reflect the intact side onto the defect and subtract the overlapping points from one another. In this way, a 3D model of the planned implant can be built in the required shape and size. The precise fit of the implant can be checked by printing the defective part of the skull in case it can be modified. A sterilisable silicone mould based on the finalized model was created afterwards. Polymethyl methacrylate implants were prepared directly in an aseptic environment in the operating room during surgery. Between 2005 and 2020, we performed 54 cranioplasties on 52 patients whose craniotomies were performed previously for indications of traumatic brain injury, stroke or tumour surgeries. No technical problems were noted during the operations. In 2 cases, septic complications that occurred were not connected to the technique itself, and the implants were removed and later replaced. Our proposed technique based on 3D-printed individual silicone moulds is a reliable, safe, easily reproducible and low-cost method to repair different skull defects.
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... It is important to address this choice in a trial, particularly because craniectomy necessitates a subsequent operation for reconstructing the skull (termed cranioplasty) that has risks. 12 We conducted a multicenter, randomized, controlled trial to compare the outcomes of craniotomy and decompressive craniectomy in adult patients with traumatic acute subdural hematoma. ...
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... It is important to address this choice in a trial, particularly because craniectomy necessitates a subsequent operation for reconstructing the skull (termed cranioplasty) that has risks. 12 We conducted a multicenter, randomized, controlled trial to compare the outcomes of craniotomy and decompressive craniectomy in adult patients with traumatic acute subdural hematoma. ...
Decompressive Craniectomy versus Craniotomy for Acute Subdural Hematoma
Article
Full-text available
  • Apr 2023
  • NEW ENGL J MED
BACKGROUND Traumatic acute subdural hematomas frequently warrant surgical evacuation by means of a craniotomy (bone flap replaced) or decompressive craniectomy (bone flap not replaced). Craniectomy may prevent intracranial hypertension, but whether it is associated with better outcomes is unclear. METHODS We conducted a trial in which patients undergoing surgery for traumatic acute subdural hematoma were randomly assigned to undergo craniotomy or decompressive craniectomy. An inclusion criterion was a bone flap with an anteroposterior diameter of 11 cm or more. The primary outcome was the rating on the Extended Glasgow Outcome Scale (GOSE) (an 8-point scale, ranging from death to “upper good recovery” [no injury-related problems]) at 12 months. Secondary outcomes included the GOSE rating at 6 months and quality of life as assessed by the EuroQol Group 5-Dimension 5-Level questionnaire (EQ-5D-5L). RESULTS A total of 228 patients were assigned to the craniotomy group and 222 to the decompressive craniectomy group. The median diameter of the bone flap was 13 cm (interquartile range, 12 to 14) in both groups. The common odds ratio for the differences across GOSE ratings at 12 months was 0.85 (95% confidence interval, 0.60 to 1.18; P=0.32). Results were similar at 6 months. At 12 months, death had occurred in 30.2% of the patients in the craniotomy group and in 32.2% of those in the craniectomy group; a vegetative state occurred in 2.3% and 2.8%, respectively, and a lower or upper good recovery occurred in 25.6% and 19.9%. EQ-5D-5L scores were similar in the two groups at 12 months. Additional cranial surgery within 2 weeks after randomization was performed in 14.6% of the craniotomy group and in 6.9% of the craniectomy group. Wound complications occurred in 3.9% of the craniotomy group and in 12.2% of the craniectomy group. CONCLUSIONS Among patients with traumatic acute subdural hematoma who underwent craniotomy or decompressive craniectomy, disability and quality-of-life outcomes were similar with the two approaches. Additional surgery was performed in a higher proportion of the craniotomy group, but more wound complications occurred in the craniectomy group. (Funded by the National Institute for Health and Care Research; RESCUE-ASDH ISRCTN Registry number, ISRCTN87370545. opens in new tab.)
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Cranioplasty in the Sultanate of Oman: A retrospective review of cases from the National Craniofacial Center 2012–2022
Article
Full-text available
  • Mar 2024
Objectives Cranioplasty is a complex craniofacial and neurosurgical procedure that aims to reinstate the architecture of the cranial vault and elevate both its aesthetic and neurological function. Several reconstructive materials have been thoroughly explored in the search for the optimal solution for cranioplasty. This study aimed to evaluate different material used for cranial reconstruction in Oman. Methods This retrospective study included all patients who had had cranioplasty procedures performed at Khoula Hospital, Muscat, Oman, from 2012 to 2022. Demographic information, the characteristics of the cranial defect and any complications that occurred post-operatively were analysed. Results A total of 47 patients were included in this study. The most common cause of cranial defects was craniectomy following traumatic head injury (70.2%) along with excision of fibrous dysplasia (10.6%). The most frequently utilised material for cranial repair was autologous bone grafts (n = 28), followed by polyetheretherketone (PEEK; n = 14). Interestingly, the replacement of bone grafts from previous craniectomy showed a notably high resorption rate (71.4%), in contrast to split calvarial grafts (0%) and other types of bone grafts (14.3%). Additionally, delayed graft infection was observed in 3.6% of the bone graft group and 7.1% of the PEEK group. Conclusion Patient-specific alloplastic implants such as PEEK have gained popularity for large and complex cranioplasty, as they provide excellent aesthetic outcomes and leave no donor site morbidity. In contrast, bone grafts remain the gold standard for small to medium-sized cranial defects.
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Toward Highly Matching the Dura Mater: A Polyurethane Integrating Biocompatible, Leak-Proof, and Self-Healing Properties
Article
  • May 2023
  • MACROMOL BIOSCI
The dura mater is the final barrier against cerebrospinal fluid leakage and plays a crucial role in protecting and supporting the brain and spinal cord. Head trauma, tumor resection, and other traumas damage it, requiring artificial dura mater for repair. However, surgical tears are often unavoidable. To address these issues, the ideal artificial dura mater should have biocompatibility, anti-leakage, and self-healing properties. Here, we have used biocompatible polycaprolactone diol as the soft segment and introduced dynamic disulfide bonds into the hard segment, achieving a multifunctional polyurethane (LSPU-2), which integrated the above-mentioned properties required in surgery. In particular, LSPU-2 matched the mechanical properties of the dura mater and the biocompatibility tests with mouse hippocampal neuronal cells demonstrated extremely low cytotoxicity and did not cause any negative skin lesions. In addition, the anti-leakage properties of the LSPU-2 were confirmed by the water permeability tester and the 900 mm H2 O static pressure test with artificial cerebrospinal fluid. Due to the disulfide bond exchange and molecular chain mobility, LSPU-2 could be completely self-healed within 115 min at human body temperature. Thus, LSPU-2 comprises one of the most promising potential artificial dura materials, which is essential for the advancement of artificial dura mater and brain surgery. This article is protected by copyright. All rights reserved.
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Infection-related failure of autologous versus allogenic cranioplasty after decompressive hemicraniectomy – A systematic review and meta-analysis
Article
Full-text available
  • May 2023
Introduction: Cranioplasty is required after decompressive craniectomy (DC) to restore brain protection and cosmetic appearance, as well as to optimize rehabilitation potential from underlying disease. Although the procedure is straightforward, complications either caused by bone flap resorption (BFR) or graft infection (GI), contribute to relevant comorbidity and increasing health care cost. Synthetic calvarial implants (allogenic cranioplasty) are not susceptible to resorption and cumulative failure rates (BFR and GI) tend therefore to be lower in comparison with autologous bone. The aim of this review and meta-analysis is to pool existing evidence of infection-related cranioplasty failure in autologous versus allogenic cranioplasty, when bone resorption is removed from the equation. Materials and methods: A systematic literature search in PubMed, EMBASE, and ISI Web of Science medical databases was performed on three time points (2018, 2020 and 2022). All clinical studies published between January 2010 and December 2022, in which autologous and allogenic cranioplasty was performed after DC, were considered for inclusion. Studies including non-DC cranioplasty and cranioplasty in children were excluded. The cranioplasty failure rate based on GI in both autologous and allogenic groups was noted. Data were extracted by means of standardized tables and all included studies were subjected to a risk of bias (RoB) assessment using the Newcastle-Ottawa assessment tool. Results: A total of 411 articles were identified and screened. After duplicate removal, 106 full-texts were analyzed. Eventually, 14 studies fulfilled the defined inclusion criteria including one randomized controlled trial, one prospective and 12 retrospective cohort studies. All but one study were rated as of poor quality based on the RoB analysis, mainly due to lacking disclosure why which material (autologous vs. allogenic) was chosen and how GI was defined. The infection-related cranioplasty failure rate was 6.9% (125/1808) for autologous and 8.3% (63/761) for allogenic implants resulting in an OR 0.81, 95% CI 0.58 to 1.13 (Z = 1.24; p = 0.22). Conclusion: In respect to infection-related cranioplasty failure, autologous cranioplasty after decompressive craniectomy does not underperform compared to synthetic implants. This result must be interpreted in light of limitations of existing studies. Risk of graft infection does not seem a valid argument to prefer one implant material over the other. Offering an economically superior, biocompatible and perfect fitting cranioplasty implant, autologous cranioplasty can still have a role as the first option in patients with low risk of developing osteolysis or for whom BFR might not be of major concern. Trial registration: This systematic review was registered in the international prospective register of systematic reviews. PROSPERO: CRD42018081720.
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Bone flap infections after craniotomy. A review of 63 cases and the implications for definitions, classification and surveillance methodologies
Article
  • Mar 2023
  • J HOSP INFECT
Background: Bone flap infections (BFI) occur following neurosurgical procedures such as craniotomies. However, they are poorly defined and often not clearly differentiated from other surgical site infection neurosurgery. Aim: To review data from a national adult neurosurgical centre to explore some clinical aspects to better inform definitions, classification and surveillance methodologies. Methods: We retrospectively reviewed data on clinical samples sent for culture from patients with suspected BFI. We also accessed information recorded prospectively from national and local databases for evidence of BFI or related conditions based upon terms used in surgical operative notes or discharge summaries and documented monomicrobial and polymicrobial infections related to craniotomy sites. Findings: Between January 2016 and December 2020, we documented 63 patients with a mean age of 45 years (16-80). Craniectomy for infection of the skull was the most common terminology used to describe BFI in the coding used in a national database, 40/63 (63%), but other terms were used. A malignant neoplasm was the most common underlying condition necessitating craniectomy in 28/63 (44%) cases. Specimens submitted for microbiological investigation included 48/63 (76%) bone flaps, 38/63 (60%) fluid/pus, and 29/63 (46%) tissue. Fifty-eight (92%) patients had at least one culture positive specimen; 32 (55%) were monomicrobial and 26 (45%) were polymicrobial. Gram-positive bacteria predominated and Staphylococcus aureus was the most common. Conclusion: Greater clarity on how to define BFI is required to enable better classification and the carrying out of appropriate surveillance. This will inform preventative strategies and more effective patient management.
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Consensus statement from the international consensus meeting on post-traumatic cranioplasty
Article
Full-text available
  • Feb 2021
  • ACTA NEUROCHIR
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.
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Cranial bone flap resorption—pathological features and their implications for clinical treatment
Article
Full-text available
  • Aug 2021
  • NEUROSURG REV
Cranioplasty following decompressive craniectomy (DC) has a primary complication when using the autologous bone: aseptic bone resorption (ABR). So far, risk factors such as age, number of fragments, and hydrocephalus have been identified but a thorough understanding of the underlying pathophysiology is still missing. The aim of this osteopathological investigation was to gain a better understanding of the underlying processes. Clinical data of patients who underwent surgical revision due to ABR was collected. Demographics, the time interval between craniectomy and cranioplasty, and endocrine serum parameters affecting bone metabolism were collected. Removed specimens underwent qualitative and quantitative histological examination. Two grafts without ABR were examined as controls. Compared to the controls, the typical layering of the cortical and cancellous bone was largely eliminated in the grafts. Histological investigations revealed the coexistence of osteolytic and osteoblastic activity within the necrosis. Bone appositions were distributed over the entire graft area. Remaining marrow spaces were predominantly fibrotic or necrotic. In areas with marrow cavity fibrosis, hardly any new bone tissue was found in the adjacent bone, while there were increased signs of osteoclastic resorption. Insufficient reintegration of the flap may be due to residual fatty bone marrow contained in the bone flap which seems to act as a barrier for osteogenesis. This may obstruct the reorganization of the bone structure, inducing aseptic bone necrosis. Following a path already taken in orthopedic surgery, thorough lavage of the implant to remove the bone marrow may be a possibility, but will need further investigation.
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Risk‐Of‐Bias VISualization (robvis): an R package and Shiny web app for visualizing risk‐of‐bias assessments
Article
Full-text available
  • Apr 2020
Despite a major increase in the range and number of software offerings now available to help researchers produce evidence syntheses, there is currently no generic tool for producing figures to display and explore the risk‐of‐bias assessments that routinely take place as part of systematic review. However, tools such as the R programming environment and Shiny (an R package for building interactive web apps) have made it straightforward to produce new tools to help in producing evidence syntheses. We present a new tool, robvis (Risk‐Of‐Bias VISualization), available as an R package and web app, which facilitates rapid production of publication‐quality risk‐of‐bias assessment figures. We present a timeline of the tool’s development and its key functionality. This article is protected by copyright. All rights reserved.
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The impact of implant material and patient age on the long-term outcome of secondary cranioplasty following decompressive craniectomy for severe traumatic brain injury
Article
Full-text available
  • Apr 2020
  • ACTA NEUROCHIR
Background Secondary cranioplasty (CP) is considered to support the neurological recovery of patients after decompressive craniectomy (DC), but the treatment success might be limited by complications associated to confounders, which are not yet fully characterized. The aim of this study was to identify the most relevant factors based on the necessity to perform revision surgeries.Methods Data from 156 patients who received secondary CP following DC for severe traumatic brain injury (TBI) between 1984 and 2015 have been retrospectively analyzed and arranged into cohorts according to the occurrence of complications requiring surgical intervention.ResultsCox regression analysis revealed a lower revision rate in patients with polymethylmethacrylate (PMMA) implants than in patients with autologous calvarial bone (ACB) implants (HR 0.2, 95% CI 0.1 to 1.0, p = 0.04). A similar effect could be observed in the population of patients aged between 18 and 65 years, who had a lower risk to suffer complications requiring surgical treatment than individuals aged under 18 or over 65 years (HR 0.4, 95% CI 0.2 to 0.9, p = 0.02). Revision rates were not influenced by the gender (p = 0.88), timing of the CP (p = 0.53), the severity of the TBI (p = 0.86), or the size of the cranial defect (p = 0.16).Conclusions In this study, the implant material and patient age were identified as the most relevant parameters independently predicting the long-term outcome of secondary CP. The use of PMMA was associated with lower revision rates than ACB and might provide a therapeutic benefit for selected patients with traumatic cranial defects.
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Aseptic bone-flap resorption after cranioplasty - incidence and risk factors
Article
Full-text available
Objective One of the common complications occurring after cranioplasty (CP) is aseptic bone-flap resorption (ABFR). Reoperation necessary because of the development of ABFR can lead to unfavorable complications during subsequent surgery using a synthetic skull implant, and also necessarily leads to higher costs. The aim of this study is to identify prognostic factors that may help to predict the development of ABFR. Methods In this study, 303 CP surgeries performed between 2002 and 2017 were examined retrospectively to identify factors predicting the occurrence of ABFR. A number of these factors (e.g., time lapse between decompressive craniectomy (DC) and CP, bone-flap size, specific laboratory signs, and the reason for the original DC) were analyzed as possibly influencing the risk of developing ABFR. Results ABFR of an autologous bone flap that subsequently required a CP with synthetic skull implants occurred in 10 of 303 patients (3.0%). CP timing and patients' Karnofsky Performance Scores (KPS) (p = 0.008; p = 0.012) were identified as significant factors with an impact on the development of ABRF. Age did not reveal a significant value, but statistical analysis shows a clear trend. The younger the age, the more likely it was that an ABFR would develop. Conclusion The risk of ABFR lessens the longer the period of time elapsed between DC and CP. Age does not reveal a significant value, but statistical analysis shows that there is a clear trend.
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Bone Flap Resorption in Pediatric Patients Following Autologous Cranioplasty
Article
  • Jan 2021
Following a decompressive craniectomy, the autologous bone flap is generally considered the reconstructive material of choice in pediatric patients. Replacement of the original bone flap takes advantage of its natural biocompatibility and the associated low risk of rejection, as well as the potential to reintegrate with the adjacent bone and subsequently grow with the patient. However, despite these advantages and unlike adult patients, the replaced calvarial bone is more likely to undergo delayed bone resorption in pediatric patients, ultimately requiring revision surgery. In this review, we describe the materials that are currently available for pediatric cranioplasty, the advantages and disadvantages of autologous calvarial replacement, the incidence and classification of bone resorption, and the clinical risk factors for bone flap resorption that have been identified to date.
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Clinical and radiological risk factors of autograft cranioplasty resorption after decompressive craniectomy for traumatic brain injury
Article
  • Jun 2020
  • CLIN NEUROL NEUROSUR
Objective The repositioning of an autologous bone flap after decompressive craniectomy (DC) for traumatic intracranial hypertension remains the first-line treatment for cranial reconstruction. Aseptic autologous bone flap resorption (BFR) is the most frequent complication. The identification of possible predictive parameters for BFR would help to improve the management of these patients. Patients and methods Three hundred and nine patients undergoing autologous bone flap repositioning after previous DC for TBI between September 2003 and September 2017 were included in the study. Results BFR was identified in 76 (24,59 %) of the 309 patients undergoing autologous CP. Age of ≤ 45 years and CP bone fragmentation were seen to be significant independent risk factors for BFR (p = 0.001 and p = 0.018, respectively) using multivariate logistic regression analysis. Of the radiologic predictors, CP size and the gap between CP and the skull defect were independently associated with BFR (p = 0.034 and p = 0.0003, respectively). The Youden index and ROC curve analysis were used to estimate the cut-off values for the continuous parameters and determine the sensitivity and specificity of the radiologic risk factors. The cut-off value for these two factors was found to be 114,98 cm2 and ≥ 578,5 mm2, respectively. The area under the ROC curve was 0.627 for bone flap size and 0.758 for the DC–CP gap. The DC–CP gap had greater sensitivity and specificity as a predictor of BFR, compared to bone flap size (p = 0.079 and p = ≤ 0.001, respectively). Conclusions In this large cohort of patients with autologous cranioplasty, younger age, fragmented autologous bone flap and a wide gap between CP and cranial defect were predictive of bone flap resorption.
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Comparison of complications in cranioplasty with various materials: a systematic review and meta-analysis
Article
  • Apr 2020
Objective: Meta-analysis to evaluate complications in the use of autogenous bone and bone substitutes and to compare bone substitutes, specifically HA, polyetheretherketone (PEEK) and titanium materials. Methods: Search of PubMed, Cochrane, Embase and Google scholar to identify all citations from 2010 to 2019 reporting complications regarding materials used in cranioplasty. Results: 20 of 2266 articles met the inclusion criteria, including a total of 2913 patients. The odds of overall complication were significantly higher in the autogenous bone group (n = 214/644 procedures, 33.2%) than the bone substitute groups (n = 116/436 procedures, 26.7%, CI 1.29–2.35, p < 0.05). In bone substitutes groups, there was no significant difference in overall complication rate between HA and Ti (OR, 1.2; 95% CI, 0.47–3.14, p = 0.69). PEEK has lower overall complication rates (OR, 0.51; 95% CI, 0.30–0.87, p = 0.01) and lower implant exposure rates (OR, 0.17; 95% CI, 0.06–0.53, p = 0.002) than Ti, but there was no significant difference in infection rates and postoperative hematoma rates. Conclusions: Cranioplasty is associated with high overall complication rates with the use of autologous bone grafts compared with bone substitutes. PEEK has a relatively low overall complication rates in substitutes groups, but still high infection rates and postoperative hematoma rates. Thus, autologous bone grafts should only be used selectively, and prospective long-term studies are needed to further refine a better material in cranioplasty.
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RoB 2: A revised tool for assessing risk of bias in randomised trials
Article
  • Aug 2019
Assessment of risk of bias is regarded as an essential component of a systematic review on the effects of an intervention. The most commonly used tool for randomised trials is the Cochrane risk-of-bias tool. We updated the tool to respond to developments in understanding how bias arises in randomised trials, and to address user feedback on and limitations of the original tool.
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