Early cranioplasty vs. late cranioplasty for the treatment of cranial defect: A systematic review

Decompressive craniectomy in trauma: What you need to know

ABSTRACT

Decompressive craniectomy (DC) is a surgical procedure in which a large section of the skull is removed, and the underlying dura mater is opened widely. After evacuating a traumatic acute subdural hematoma, a primary DC is typically performed if the brain is bulging or if brain swelling is expected over the next several days. However, a recent randomized trial found similar 12-month outcomes when primary DC was compared with craniotomy for acute subdural hematoma. Secondary removal of the bone flap was performed in 9% of the craniotomy group, but more wound complications occurred in the craniectomy group. Two further multicenter trials found that, whereas early neuroprotective bifrontal DC for mild to moderate intracranial hypertension is not superior to medical management, DC as a last-tier therapy for refractory intracranial hypertension leads to reduced mortality. Patients undergoing secondary last-tier DC are more likely to improve over time than those in the standard medical management group. The overall conclusion from the most up-to-date evidence is that secondary DC has a role in the management of intracranial hypertension following traumatic brain injury but is not a panacea. Therefore, the decision to offer this operation should be made on a case-by-case basis. Following DC, cranioplasty is warranted but not always feasible, especially in low- and middle-income countries. Consequently, a decompressive craniotomy, where the bone flap is allowed to "hinge" or "float," is sometimes used. Decompressive craniotomy is also an option in a subgroup of traumatic brain injury patients undergoing primary surgical evacuation when the brain is neither bulging nor relaxed. However, a high-quality randomized controlled trial is needed to delineate the specific indications and the type of decompressive craniotomy in appropriate patients.

From imaging to personalized 3D printed molds in cranioplasty

Cranioplasty is the surgical repair of a bone defect in the skull resulting from a previous operation or injury, which involves lifting the scalp and restoring the contour of the skull with a graft made from material that is reconstructed from scans of the patient's own skull. The paper introduces a 3D printing technology in creating molds, which are filled with polymethyl methacrylate (PMMA) to reconstruct the missing bone part of the skull. The procedure included several steps to create a 3D model in an STL format, conversion into a G-code which is further used to produce the mold itself using a 3D printer. The paper presents our initial experience with 5 patients who undergone cranioplasty utilizing 3D printed molds. Making a patient-specific model is a very complex process and consists of several steps. The creation of a patient-specific 3D model loading of DICOM images obtained by CT scanning, followed by thresholding-based segmentation and generation of a precise 3D model of part of the patient's skull. Next step is creating the G-code models for 3D printing, after which the actual models are printed using Fused Deposition Modeling printer and PLA material. All surgeries showed good match of the missing bone part and part created using 3D printed mold, without additional steps in refinement. In such a way, 3D printing technology helps in creating personalized and visually appealing bone replacements, at a low cost of the final product.

Perioperative risk factors for major complications after bone replacement in decompressive craniectomy

INTRODUCTION

Bone flap replacement after a decompressive craniectomy is a low complexity procedure, but with complications that can negatively impact the patient's outcome. A better knowledge of the risk factors for these complications could reduce their incidence.

PATIENTS AND METHODS

A retrospective review of a series of 50 patients who underwent bone replacement after decompressive craniectomy at a tertiary center over a 10-year period was performed. Those clinical variables related to complications after replacement were recorded and their risk factors were analyzed.

RESULTS

A total of 18 patients (36%) presented complications after bone flap replacement, of which 10 (55.5%) required a new surgery for their treatment. Most of the replacements (95%) were performed in the first 90 days after the craniectomy, with a tendency to present more complications compared to the subsequent period (37.8% vs 20%, p > 0.05). The most frequent complication was subdural hygroma, which appeared later than infection, the second most frequent complication. The need for ventricular drainage or tracheostomy and the mean time on mechanical ventilation, ICU admission, or waiting until bone replacement were greater in patients who presented post-replacement complications. Previous infections outside the nervous system or the surgical wound was the only risk factor for post-bone flap replacement complications (p = 0.031).

CONCLUSIONS

Postoperative complications were recorded in more than a third of the patients who underwent cranial bone flap replacement, and at least half of them required a new surgery. A specific protocol aimed at controlling previous infections could reduce the risk of complications and help establish the optimal time for cranial bone flap replacement.

Quantitative Analysis of Brain Swelling Resolution With Regard to Cranioplasty After Decompressive Craniectomy

OBJECTIVE

Adequate brain swelling resolution prior to cranioplasty (CP) is an important yet loosely defined issue. Despite efforts to balance timely CP and patient safety, heterogeneous study methodologies have led to conflicting results. This study aims to standardize this issue through quantifying degree of brain swelling resolution using a proposed Visual CP Scale.

METHODS

The proposed Visual CP Scale is validated through a 2-pronged approach. The first prong involves a national survey in Taiwan, where neurosurgeons were surveyed to determine what constitutes a patient's readiness for CP. The second prong involves a large retrospective cohort, where the correlations between timing, degree of brain swelling resolution, and post-CP complication rates, are evaluated.

RESULTS

In the national Taiwan CP Survey, 124 out of 772 neurosurgeons (17.2%) completed the survey. Respondents who chose higher grades on the Visual CP Scale preferred later CP timings. In the retrospective data, 378 out of 770 (49.1%) patients had pre-CP brain images, allowing for the utilization of the Visual CP Scale. A Visual CP Scale score of greater than or equal to 4 was associated with fewer complications after CP.

CONCLUSIONS

The timing of CP should be determined by the degree of brain swelling resolution, not vice versa. The proposed Visual CP Scale offers an objective method for assessing brain swelling resolution, making it an adjuvant tool for clinical decision-making and future research related to CP.

A 2-Year Prospective Study of Complication Rates After Cranioplasty: Is 8 Weeks' Interval Associated with Increased Complications?

BACKGROUND

The commonly observed complications after cranioplasty include infections, intracranial hemorrhage, and seizures. The timing of cranioplasty after decompressive craniectomy (DC) is still under debate, with literature available for both early and delayed cranioplasties. The objectives of this study were to note the overall complication rates and more specifically compare complications between 2 different time intervals.

METHODS

This was a 24-month, single-center, prospective study. Since timing is the most debated variable, the study cohort was divided into 2 groups (≤8 weeks and >8 weeks). Furthermore, other variables such as age, gender, etiology of DC, neurologic condition, and blood loss were correlated with complications.

RESULTS

A total of 104 cases were analyzed. Two thirds were traumatic etiology. The mean and median DC-cranioplasty intervals were 11.3 weeks (range 4-52 weeks) and 9 weeks, respectively. Seven complications (6.7%) were observed in 6 patients. There was no statistical difference observed between any of the variables and complications.

CONCLUSIONS

We observed that performing cranioplasty within 8 weeks of the initial DC surgery is safe and noninferior to cranioplasty performed after 8 weeks. Therefore if the general condition of the patient is satisfactory, we are of the opinion that an interval of 6-8 weeks from the primary DC is safe and a reasonable time frame for performing cranioplasty.

Optimal Timing of Cranioplasty and Predictors of Overall Complications After Cranioplasty: The Impact of Brain Collapse

BACKGROUND

The optimal timing of cranioplasty (CP) and predictors of overall postoperative complications are still controversial.

OBJECTIVE

To determine the optimal timing of CP.

METHODS

Patients were divided into collapsed group and noncollapsed group based on brain collapse or not, respectively. Brain collapse volume was calculated in a 3-dimensional way. The primary outcomes were overall complications and outcomes at the 12-month follow-up after CP.

RESULTS

Of the 102 patients in this retrospective observation cohort study, 56 were in the collapsed group, and 46 were in the noncollapsed group. Complications were noted in 30.4% (n = 31), 24 (42.9%) patients in the collapsed group and 7 (15.2%) patients in the noncollapsed group, with a significant difference ( P = .003). Thirty-three (58.9%) patients had good outcomes (modified Rankin Scale 0-3) in the collapsed group, and 34 (73.9%) patients had good outcomes in the noncollapsed group without a statistically significant difference ( P = .113). Brain collapse ( P = .005) and Karnofsky Performance Status score at the time of CP ( P = .025) were significantly associated with overall postoperative complications. The cut-off value for brain collapse volume was determined as 11.26 cm 3 in the receiver operating characteristic curve. The DC-CP interval was not related to brain collapse volume or postoperative complications.

CONCLUSION

Brain collapse and lower Karnofsky Performance Status score at the time of CP were independent predictors of overall complications after CP. The optimal timing of CP may be determined by tissue window based on brain collapse volume instead of time window based on the decompressive craniectomy-CP interval.

Surgery for Malignant Acute Ischemic Stroke: A Narrative Review of the Knowns and Unknowns

Malignant acute ischemic stroke (AIS) is characterized by acute neurological deterioration caused by progressive space-occupying brain edema, often occurring in the first hours to days after symptom onset. Without any treatment, the result is often fatal. Despite advances in treatment for AIS, up to 80% of patients with a large hemispheric stroke or cerebellar stroke are at risk of poor outcome. Decompressive surgery can be life-saving in a subgroup of patients with malignant AIS, but uncertainties exist on patient selection, predictors of malignant infarction, perioperative management, and timing of intervention. Although survivors are left disabled, most agree with the original decision to undergo surgery and would make the same decision again. In this narrative review, we focus on the clinical and radiological predictors of malignant infarction in AIS and outline the technical aspects of decompressive surgery as well as duraplasty and cranioplasty. We discuss the current evidence and recommendations for surgery in AIS, highlighting gaps in knowledge, and suggest directions for future studies. KEY POINTS: · Acute ischemic stroke from occlusion of a proximal intracranial artery can progress quickly to malignant edema, which can be fatal in 80% of patients despite medical management.. · Decompression surgery is life-saving within 48 hours of stroke onset, but the benefits beyond this time and in the elderly are unknown.. · Decompressive surgery is associated with high morbidity, particularly in the elderly. The decision to operate must be made after considering the individual's preference and expectations of quality of life in the context of the clinical condition.. · Further studies are needed to refine surgical technique including value of duraplasty and understand the role monitoring intracranial pressure during and after decompressive surgery.. · More studies are needed on the pathophysiology of malignant cerebral edema, prediction models including imaging and biomarkers to identify which subgroup of patients will benefit from decompressive surgery.. · More research is needed on factors associated with morbidity and mortality after cranioplasty, safety and efficacy of implants, and comparisons between them.. · Further studies are needed to assess the long-term effects of physical disability and quality of life of survivors after surgery, particularly those with severe neurological deficits..

Bespoke Implants for Cranial Reconstructions: Preoperative to Postoperative Surgery Management System

Traumatic brain injury is a leading cause of death and disability worldwide, with nearly 90% of the deaths coming from low- and middle-income countries. Severe cases of brain injury often require a craniectomy, succeeded by cranioplasty surgery to restore the integrity of the skull for both cerebral protection and cosmetic purposes. The current paper proposes a study on developing and implementing an integrative surgery management system for cranial reconstructions using bespoke implants as an accessible and cost-effective solution. Bespoke cranial implants were designed for three patients and subsequent cranioplasties were performed. Overall dimensional accuracy was evaluated on all three axes and surface roughness was measured with a minimum value of 2.209 μm for Ra on the convex and concave surfaces of the 3D-printed prototype implants. Improvements in patient compliance and quality of life were reported in postoperative evaluations of all patients involved in the study. No complications were registered from both short-term and long-term monitoring. Material and processing costs were lower compared to a metal 3D-printed implants through the usage of readily available tools and materials, such as standardized and regulated bone cement materials, for the manufacturing of the final bespoke cranial implants. Intraoperative times were reduced through the pre-planning management stages, leading to a better implant fit and overall patient satisfaction.

3D bioprinted autologous bone particle scaffolds for cranioplasty promote bone regeneration with both implanted and native BMSCs

Although autologous bone (AB) grafting is considered to be the gold standard for cranioplasty, unresolved problems remain, such as surgical-site infections and bone flap absorption. In this study, an AB scaffold was constructed via three-dimensional (3D) bedside-bioprinting technology and used for cranioplasty. To simulate the skull structure, a polycaprolactone shell was designed as an external lamina, and 3D-printed AB and a bone marrow-derived mesenchymal stem cell (BMSC) hydrogel was used to mimic cancellous bone for bone regeneration. Ourin vitroresults showed that the scaffold exhibited excellent cellular affinity and promoted osteogenic differentiation of BMSCs in both two-dimensional and 3D culture systems. The scaffold was implanted in beagle dog cranial defects for up to 9 months, and the scaffold promoted new bone and osteoid formation. Furtherin vivostudies indicated that transplanted BMSCs differentiated into vascular endothelium, cartilage, and bone tissues, whereas native BMSCs were recruited into the defect. The results of this study provide a method for bedside bioprinting of a cranioplasty scaffold for bone regeneration, which opens up another window for clinical applications of 3D printing in the future.

Next-generation personalized cranioplasty treatment

Decompressive craniectomy (DC) is a surgical procedure, that is followed by cranioplasty surgery. DC is usually performed to treat patients with traumatic brain injury, intracranial hemorrhage, cerebral infarction, brain edema, skull fractures, etc. In many published clinical case studies and systematic reviews, cranioplasty surgery is reported to restore cranial symmetry with good cosmetic outcomes and neurophysiologically relevant functional outcomes in hundreds of patients. In this review article, we present a number of key issues related to the manufacturing of patient-specific implants, clinical complications, cosmetic outcomes, and newer alternative therapies. While discussing alternative therapeutic treatments for cranioplasty, biomolecules and cellular-based approaches have been emphasized. The current clinical practices in the restoration of cranial defects involve 3D printing to produce patient-specific prefabricated cranial implants, that provide better cosmetic outcomes. Regardless of the advancements in image processing and 3D printing, the complete clinical procedure is time-consuming and requires significant costs. To reduce manual intervention and to address unmet clinical demands, it has been highlighted that automated implant fabrication by data-driven methods can accelerate the design and manufacturing of patient-specific cranial implants. The data-driven approaches, encompassing artificial intelligence (machine learning/deep learning) and E-platforms, such as publicly accessible clinical databases will lead to the development of the next generation of patient-specific cranial implants, which can provide predictable clinical outcomes. STATEMENT OF SIGNIFICANCE: Cranioplasty is performed to reconstruct cranial defects of patients who have undergone decompressive craniectomy. Cranioplasty surgery improves the aesthetic and functional outcomes of those patients. To meet the clinical demands of cranioplasty surgery, accelerated designing and manufacturing of 3D cranial implants are required. This review provides an overview of biomaterial implants and bone flap manufacturing methods for cranioplasty surgery. In addition, tissue engineering and regenerative medicine-based approaches to reduce clinical complications are also highlighted. The potential use of data-driven computer applications and data-driven artificial intelligence-based approaches are emphasized to accelerate the clinical protocols of cranioplasty treatment with less manual intervention and shorter intraoperative time.

Analysis of PMMA versus CaP titanium-enhanced implants for cranioplasty after decompressive craniectomy: a retrospective observational cohort study

Numerous materials of implants used for cranioplasty after decompressive craniectomy (DC) have been investigated to meet certain demanded key features, such as stability, applicability, and biocompatibility. We aimed to evaluate the feasibility and safety of biocompatible calcium-phosphate (CaP) implants for cranioplasty compared to polymethylmethacrylate (PMMA) implants. In this retrospective observational cohort study, the medical records of all patients who underwent cranioplasty between January 1st, 2015, and January 1st, 2022, were reviewed. Demographic, clinical, and diagnostic data were collected. Eighty-two consecutive patients with a mean age of 52 years (range 22-72 years) who received either a PMMA (43/82; 52.4%) or CaP (39/82; 47.6%) cranial implant after DC were included in the study. Indications for DC were equally distributed in both groups. Time from DC to cranioplasty was 143.8 ± 17.5 days (PMMA) versus 98.5 ± 10.4 days (CaP). The mean follow-up period was 34.9 ± 27.1 months. Postoperative complications occurred in 13 patients with PMMA and 6 in those with CaP implants (13/43 [30.2%] vs. 6/39 [15.4%]; p = 0.115). Revision surgery with implant removal was necessary for 9 PMMA patients and in 1 with a CaP implant (9/43 [20.9%] vs. 1/39 [2.6%]; p = 0.0336); 6 PMMA implants were removed due to surgical site infection (SSI) (PMMA 6/43 [14%] vs. CaP 0/39 [0%]; p = 0.012). In this study, a biocompatible CaP implant seems to be superior to a PMMA implant in terms of SSI and postoperative complications. The absence of SSI supports the idea of the biocompatible implant material with its ability for osseointegration.

Complications associated with early cranioplasty for patients with traumatic brain injury: a 25-year single-center analysis

OBJECTIVE

Cranioplasty is a technically simple procedure, although one with potentially high rates of complications. The ideal timing of cranioplasty should minimize the risk of complications, but research investigating cranioplasty timing and risk of complications has generated diverse findings. Previous studies have included mixed populations of patients undergoing cranioplasty following decompression for traumatic, vascular, and other cerebral insults, making results challenging to interpret. The objective of the current study was to examine rates of complications associated with cranioplasty, specifically for patients with traumatic brain injury (TBI) receiving this procedure at the authors' high-volume level 1 trauma center over a 25-year time period.

METHODS

A single-institution retrospective review was conducted of patients undergoing cranioplasty after decompression for trauma. Patients were identified and clinical and demographic variables obtained from 2 neurotrauma databases. Patients were categorized into 3 groups based on timing of cranioplasty: early (≤ 90 days after craniectomy), intermediate (91-180 days after craniectomy), and late (> 180 days after craniectomy). In addition, a subgroup analysis of complications in patients with TBI associated with ultra-early cranioplasty (< 42 days, or 6 weeks, after craniectomy) was performed.

RESULTS

Of 435 patients identified, 141 patients underwent early cranioplasty, 187 patients received intermediate cranioplasty, and 107 patients underwent late cranioplasty. A total of 54 patients underwent ultra-early cranioplasty. Among the total cohort, the mean rate of postoperative hydrocephalus was 2.8%, the rate of seizure was 4.6%, the rate of postoperative hematoma was 3.4%, and the rate of infection was 6.0%. The total complication rate for the entire population was 16.8%. There was no significant difference in complications between any of the 3 groups. No significant differences in postoperative complications were found comparing the ultra-early cranioplasty group with all other patients combined.

CONCLUSIONS

In this cohort of patients with TBI, early cranioplasty, including ultra-early procedures, was not associated with higher rates of complications. Early cranioplasty may confer benefits such as shorter or fewer hospitalizations, decreased financial burden, and overall improved recovery, and should be considered based on patient-specific factors.

Outcomes and Associated Complications of Cranioplasty following Craniectomy in Brunei Darussalam

Objective Cranioplasty, commonly performed after decompressive craniectomy, is associated with significant complications. We aim to characterize the outcomes and complications post cranioplasty performed in Brunei Darussalam.

Methods and Materials We conducted a nationwide retrospective study of the patients who underwent cranioplasty. Patients who underwent cranioplasty by the Neurosurgical Department from January 2014 to June 2019 were included. Patients were excluded if they did not have a minimum of 30-days follow-up or the initial cranioplasty was performed elsewhere. Outcomes including complications post cranioplasty and 30-day and 1-year failure rates were assessed. All statistical analyses were performed with SPSS version 20 (IBM Corporation, Armonk, New York, USA). The χ2 test, Student's t-test, and the Mann–Whitney U test were performed for nominal, normally, and non-normally distributed variables, respectively. Multivariate logistic regression was used to assess predictors for complications and cranioplasty failure.

Results Seventy-seven patients with a median age of 48 (interquartile range, 37–61) years were included. Most cranioplasties used autologous bone (70/77, 90.9%). Infection and overall complication rates were 3.9% and 15.6%, respectively. Cranioplasty failure (defined as removal or revision of cranioplasty) rate was 9.1%. Previous cranial site infection post craniectomy was associated with cranioplasty failure (odds ratio: 12.2, 95% confidence interval [1.3, 114.0], p=0.028).

Conclusions Cranioplasty is generally associated with significant complications, including reoperation for implant failure. We highlighted that autologous bone cranioplasties can be performed with an acceptable low rate of infection, making it a viable first option for implant material.

Ultra-Early Cranioplasty versus Conventional Cranioplasty: A Retrospective Cohort Study at an Academic Level 1 Trauma Center

The goal of this study was to ascertain the efficacy, safety, and comparability of ultra-early cranioplasty (CP; defined here as <30 days from the original craniectomy) to conventional cranioplasty (defined here as >30 days from the original craniectomy). A retrospective review of CPs performed at our institution between January 2016 and July 2020 was performed. Craniectomies initially performed at other institutions were excluded. Seventy-seven CPs were included in our study. Ultra-early CP was defined as CP performed within 30 days of craniectomy whereas conventional CP occurred after 30 days. Post-operative wound infection rates, rate of return to the operating room (OR) with or without bone flap removal, operative length, and rate of post-CP hydrocephalus were compared between the two groups. Thirty-nine and 38 patients were included in the ultra-early and conventional CP groups, respectively. The average number of days to CP in the ultra-early group was 17.70 ± 7.75 days compared to 95.70 ± 65.60 days in the conventional group. The mean Glasgow Coma Scale upon arrival to the emergency room was 7.28 ± 3.90 and 6.92 ± 4.14 for the ultra-early and conventional groups, respectively. The operative time was shorter in the ultra-early cohort than that in the conventional cohort (ultra-early, 2.40 ± 0.71 h; conventional, 3.00 ± 1.63 h; p = 0.0336). The incidence of post-CP hydrocephalus was also lower in the ultra-early cohort (ultra-early, 10.3%; conventional, 31.6%; p = 0.026). No statistically significant differences were observed regarding post-operative infection, return to the OR, or bone flap removal. Our study shows that ultra-early CP can significantly reduce the rate of post-CP hydrocephalus, as well as operative time in comparison to conventional CP. However, the timing of CP post-DC should remain a patient-centered consideration.

Cranioplasty: A Multidisciplinary Approach

Decompressive craniectomy (DC) is an operation where a large section of the skull is removed to accommodate brain swelling. Patients who survive will usually require subsequent reconstruction of the skull using either their own bone or an artificial prosthesis, known as cranioplasty. Cranioplasty restores skull integrity but can also improve neurological function. Standard care following DC consists of the performance of cranioplasty several months later as historically, there was a concern that earlier cranioplasty may increase the risk of infection. However, recent systematic reviews have challenged this and have demonstrated that an early cranioplasty (within three months after DC) may enhance neurological recovery. However, patients are often transferred to a rehabilitation unit following their acute index admission and before their cranioplasty. A better understanding of the pathophysiological effects of cranioplasty and the relationship of timing and complications would enable more focused patient tailored rehabilitation programs, thus maximizing the benefit following cranioplasty. This may maximise recovery potential, possibly resulting in improved functional and cognitive gains, enhancement of quality of life and potentially reducing longer-term care needs. This narrative review aims to update multi-disciplinary team regarding cranioplasty, including its history, pathophysiological consequences on recovery, complications, and important clinical considerations both in the acute and rehabilitation settings.

An instantly fixable and self-adaptive scaffold for skull regeneration by autologous stem cell recruitment and angiogenesis

Limited stem cells, poor stretchability and mismatched interface fusion have plagued the reconstruction of cranial defects by cell-free scaffolds. Here, we designed an instantly fixable and self-adaptive scaffold by dopamine-modified hyaluronic acid chelating Ca²⁺ of the microhydroxyapatite surface and bonding type I collagen to highly simulate the natural bony matrix. It presents a good mechanical match and interface integration by appropriate calcium chelation, and responds to external stress by flexible deformation. Meanwhile, the appropriate matrix microenvironment regulates macrophage M2 polarization and recruits endogenous stem cells. This scaffold promotes the proliferation and osteogenic differentiation of BMSCs in vitro, as well as significant ectopic mineralization and angiogenesis. Transcriptome analysis confirmed the upregulation of relevant genes and signalling pathways was associated with M2 macrophage activation, endogenous stem cell recruitment, angiogenesis and osteogenesis. Together, the scaffold realized 97 and 72% bone cover areas after 12 weeks in cranial defect models of rabbit (Φ = 9 mm) and beagle dog (Φ = 15 mm), respectively.

Limited stem cells and mismatched interface fusion have plagued biomaterial-mediated cranial reconstruction. Here, the authors engineer an instantly fixable and self-adaptive scaffold to promote calcium chelation and interface integration, regulate macrophage M2 polarization, and recruit endogenous stem cells.

Comparison of Postoperative Complications between Simultaneous and Staged Surgery in Cranioplasty and Ventriculoperitoneal Shunt Placement after Decompressive Craniectomy

Objective

Cranioplasty (CP) and ventriculoperitoneal shunt (VPS) are required procedures following decompressive craniectomy (DC) for craniofacial protection and to prevent hydrocephalus. This study assessed the safety and efficacy of simultaneous operation with CP and VPS after DC, and determined the preoperative risk factors for postoperative complications.

Methods

Between January 2009 and December 2019, 81 patients underwent CP and VPS in simultaneous or staged operations following DC. Cumulative medical records and radiologic data were analyzed using univariate analysis to identify factors predisposing patients to complications after CP and VPS.

Results

CP and VPS were performed as simultaneous or staged operations in 18 (22.2%) and 63 (77.8%) patients, respectively. The overall postoperative complication rate was 16.0% (13/81). Patients who underwent simultaneous CP and VPS were significantly more likely to experience complications when compared with patients who underwent staged operations (33.3% vs. 9.6%, p<0.01). Univariate analysis revealed that simultaneous CP and VPS surgery was the only significant predictor of postoperative complications (p=0.031).

Conclusion

This study provided detailed data on surgical timing and complications for CP and VPS after DC. We showed that simultaneous procedures were a significant risk factor for postoperative complications.

Cranioplasty Following Severe Traumatic Brain Injury: Role in Neurorecovery

PURPOSE OF REVIEW

Decompressive craniectomy (DC) is a life-saving procedure performed in refractory intracranial pressure increase and mass lesion due to severe traumatic brain injury (TBI). Cranioplasty primarily intends to maintain cerebral protection and reconstruct aesthetic appearance. Also, cranioplasty can enable neurological rehabilitation and potentially augment neurological recovery. This article reviews recent studies on the effect of cranioplasty on neurological recovery in severe TBI.

RECENT FINDINGS

Recent findings suggested that cranioplasty has the potential to enhance neurological recovery after severe TBI. Cranioplasty may alleviate cognitive and functional deficits by reinstating the regular cerebrospinal fluid dynamics and improving brain perfusion. Analyses on the effects of cranioplasty timing on neurological recovery likely favor early cranioplasty. Also, materials used during cranioplasty, autologous and exogenous, were suggested to have similar effects in recovery. Although neurological therapy of TBI patients is still a serious challenge, recent findings represent the possible enhancing effect of cranioplasty on neurological recovery.

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.

First Report of a Multicenter Prospective Registry of Cranioplasty in the United Kingdom and Ireland

BACKGROUND

There are many questions that remain unanswered regarding outcomes following cranioplasty including the timing of cranioplasty following craniectomy as well as the material used.

OBJECTIVE

To establish and evaluate 30-d outcomes for all cranial reconstruction procedures in the United Kingdom (UK) and Ireland through a prospective multicenter cohort study.

METHODS

Patients undergoing cranioplasty insertion or revision between June 1, 2019 and November 30, 2019 in 25 neurosurgical units were included. Data collected include demographics, craniectomy date and indication, cranioplasty material and date, and 30-d outcome.

RESULTS

In total, 313 operations were included, consisting of 255 new cranioplasty insertions and 58 revisions. Of the new insertions, the most common indications for craniectomy were traumatic brain injury (n = 110, 43%), cerebral infarct (n = 38, 15%), and aneurysmal subarachnoid hemorrhage (n = 30, 12%). The most common material was titanium (n = 163, 64%). Median time to cranioplasty was 244 d (interquartile range 144-385), with 37 new insertions (15%) within or equal to 90 d. In 30-d follow-up, there were no mortalities. There were 14 readmissions, with 10 patients sustaining a wound infection within 30 d (4%). Of the 58 revisions, the most common reason was due to infection (n = 33, 59%) and skin breakdown (n = 13, 23%). In 41 (71%) cases, the plate was removed during the revision surgery.

CONCLUSION

This study is the largest prospective study of cranioplasty representing the first results from the UK Cranial Reconstruction Registry, a first national registry focused on cranioplasty with the potential to address outstanding research questions for this procedure.

Comparison of subcutaneous pocket with cryopreservation method for storing autologous bone flaps in developing surgical wound infection after Cranioplasty: A randomized clinical trial

BACKGROUND

Following a decompressive craniectomy (DC), the harvested bone flap is stored for future cranioplasty. There are two different methods proposed for bone banking, namely subcutaneous pocketing (SP) in the abdominal wall and cryopreservation (CP) in a refrigerator. This study was designed to evaluate the risk of developing infection in each study group.

METHODS

In this randomized clinical trial design, a total of 143 patients underwent a primary decompressive craniectomy. Thereafter, they were randomly allocated into two groups, as SP and CP, and they were then scheduled for a future cranioplasty. Next, 108 patients underwent cranioplasty using an autologous bone flap and then followed-up for 18 months. Some variables, including demographic data, indications for primary DC, rate of post-operative clinical infection, bacterial culture results, the interval between craniectomy and cranioplasty, post-operative hospitalization duration, new morbidities, mortality rate, bone flap resorption rate, and several possible associated risk factors, were also recorded. The obtained data were analyzed by an expert bio-statistician using proper bio-statistical methods. A P value < 0.05 was considered as statistically significant.

RESULTS

Four patients in the cryopreservation group (n = 50) indicated post-operative bone flap infection (8%), which was statistically significant (P = 0.041). Accordingly, all of them were resulted as positive for Methicillin-Resistant-Staphylococcus aureus (MRSA). Using the subcutaneous pocket method, no post-operative infection was observed after cranioplasty. The overall postoperative infection rate was estimated as 4%. The mean of age in the post-operative infection group's participants was 50.25 years old, and in the non-infected, it was 34.93 years old, which was also significant (P = 0.048). Bone flap resorption (BFR) rate was found to be higher by the use of CP method in comparison to SP technique (p = 0.0001). Of note, no other risk factor was found attributable to a higher BFR rate (p-values > 0.05).

CONCLUSIONS

Older age and cryopreservation method at higher storage temperature (-18C˚) may be associated with infection's development after performing cranioplasty. BFR is more prevalent in the use of CP method rather than SP preservation technique.

Post-Cranioplasty Complications: Lessons From a Prospective Study Assessing Risk Factors

ABSTRACT

Complication rate related with cranioplasty is described as very high in most of relevant studies. The aim of our study was to try to identify possible factors, that could predict complications following cranioplasty. The authors hypothesized that some physical characteristics on the preoperative brain computed tomography (CT) scan can be predictive for complications.The authors carried out a prospective observational study. All patients were adults after decompressive craniectomy, planned for cranioplasty and had a brain CT scan the day before cranioplasty. Our data pool included demographics, reason of craniectomy, various radiological parameters, the time of cranioplasty after craniectomy, the type of cranioplasty bone flap, and the complications.Twenty-five patients were included in the study. The authors identified statistically significant correlation between time of cranioplasty after craniectomy and the complications, as well as between the type of cranioplasty implant and the complications. There was statistically significant correlation between complications and the distance of the free brain surface from the level of the largest skull defect dimension - free brain surface deformity (FBSD). Moreover, the correlation between FBSD and the time of cranioplasty was statistically significant.It seems that for adult patients with unilateral DC the shorter time interval between craniectomy and cranioplasty lowers the risk for complications. The risk seems to be decreased further, by using autologous bone flap. Low values of the FBSD increase the risk for complications. This risk factor can be avoided, by shortening the time between craniectomy and cranioplasty.

Complication Rates in Early Versus Late Cranioplasty-A 14-Year Single-Center Case Series

BACKGROUND

Cranioplasty (CP) following decompressive craniectomy (DC) is a common neurosurgical procedure for cranial cosmesis and protection. There is uncertainty regarding the complication rates and potential benefits related to the timing of CP.

OBJECTIVE

To investigate the impact of the timing of CP on complication rates for different etiologies of DC.

METHODS

A retrospective chart review was performed of all CP cases between 2004 and 2018 for traumatic and nontraumatic indications of DC. Demographics, clinical characteristics, and complications were collected. Early and late CP were defined as replacement of the bone flap at ≤90 and >90 d following DC, respectively.

RESULTS

A total of 278 patients were included, receiving 81 early and 197 late CPs. When analyzing all patients, early CP was associated with a statistically significant higher odds of any complication (odds ratio [OR]: 3.25, P < .001), reoperation (OR: 2.57, P = .019), hydrocephalus (OR: 6.03, P = .003), and symptomatic extra-axial collections (OR: 9.22, P = .003). Subgroup analysis demonstrated statistically significant higher odds of these complications only for the CP trauma subgroup, but not the nontrauma subgroup. The odds of complications postCP demonstrated a statistically significant decrease of 4.4% for each week after DC (Unit Odds Ratio [U-OR]: 0.956, P = .0363).

CONCLUSION

In our retrospective series, early CP was associated with higher odds of postoperative complications compared to late CP in the trauma subgroup. Greater care should be taken in preoperative planning and increased vigilance postoperatively for complications with this potentially more vulnerable subpopulation. Future prospective controlled trials are needed to elucidate optimal timing for CP.

Effect of cranioplasty timing on the functional neurological outcome and postoperative complications

BACKGROUND

The optimal timing for performing cranioplasty and its effect on functional outcome remains debatable. Multiple confounding factors may come into role; including the material used, surgical technique, cognitive assessment tools, and the overall complications. The aim of this study is to assess the neurological outcome and postoperative complications in patients who underwent early versus late cranioplasty.

METHODS

A retrospective cohort study was conducted to investigate the neurological outcome and postoperative complications in patients who underwent cranioplasty between 2005 and 2018 at a Level l trauma center. Early and late cranioplasties were defined as surgeries performed within and more than 90 days of decompressive craniectomy, respectively. The Glasgow Outcome Score (GOS) and modified Rankin scale (mRS), recorded within 1 week of cranioplasty, were used to assess the neurological outcome.

RESULTS

A total of 101 cases of cranioplasty were included in the study. The mean age of the patients was 31.4 ± 13.9 years. Most patients (n = 86; 85.1%) were male. The mean GOS for all patients was 4.0 ± 1.0. The mean mRS was 2.2 ± 1.78. Hydrocephalus was noted in 18 patients (early, n = 6; late, n = 12; P = 0.48). Seizures developed in 28 patients (early, n = 12; late, n = 16; P = 0.77).

CONCLUSION

The neurological outcome in patients who underwent early versus late cranioplasty is almost identical. The differences in the rates of overall postoperative complications between early versus late cranioplasty were statistically insignificant. The optimal timing for performing cranioplasty is mainly dependent on the resolution of cerebral swelling.

Transforming Growth Factor-β3/Recombinant Human-like Collagen/Chitosan Freeze-Dried Sponge Primed With Human Periodontal Ligament Stem Cells Promotes Bone Regeneration in Calvarial Defect Rats

Patients with a skull defect are at risk of developing cerebrospinal fluid leakage and ascending bacterial meningitis at >10% per year. However, treatment with stem cells has brought great hope to large-area cranial defects. Having found that transforming growth factor (TGF)-β3 can promote the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs), we designed a hybrid TGF-β3/recombinant human-like collagen recombinant human collagen/chitosan (CS) freeze-dried sponge (TRFS) loading hPDLSCs (TRFS-h) to repair skull defects in rats. CFS with 2% CS was selected based on the swelling degree, water absorption, and moisture retention. The CS freeze-dried sponge (CFS) formed a porous three-dimensional structure, as observed by scanning electron microscopy. In addition, cytotoxicity experiments and calcein-AM/PI staining showed that TRFS had a good cellular compatibility and could be degraded completely at 90 days in the implantation site. Furthermore, bone healing was evaluated using micro-computed tomography in rat skull defect models. The bone volume and bone volume fraction were higher in TRFS loaded with hPDLSCs (TRFS-h) group than in the controls (p < 0.01, vs. CFS or TRFS alone). The immunohistochemical results indicated that the expression of Runx2, BMP-2, and collagen-1 (COL Ⅰ) in cells surrounding bone defects in the experimental group was higher than those in the other groups (p < 0.01, vs. CFS or TRFS alone). Taken together, hPDLSCs could proliferate and undergo osteogenic differentiation in TRFS (p < 0.05), and TRFS-h accelerated bone repair in calvarial defect rats. Our research revealed that hPDLSCs could function as seeded cells for skull injury, and their osteogenic differentiation could be accelerated by TGF-β3. This represents an effective therapeutic strategy for restoring traumatic defects of the skull.

Calvaria critical-size defects in rats using piezoelectric equipment: a comparison with the classic trephine

Calvarial critical-size defects in rats are used to study regeneration of both craniofacial bone and long-bones. For decades, the trephine technique has been used with no notable refinements in the procedure. The use of piezoelectric surgical equipment has increased in human clinical oral and maxillofacial surgery, neurosurgery, traumatology, and orthopedics, because the devices are easy to handle, and can cut bone without damaging sensitive soft tissues such as blood vessels, nerves, and membranes. This study evaluated and compared the surgical technique and bone regeneration process between a traditional hand-drill trephine and piezoelectric equipment in a critical-size calvaria defect in a rat model. Thirty SD male rats were randomly divided into two groups and had either a 7.9mm diameter circular defect created with trephine or a 7.0mm square defect using the piezoelectric device, both creating 49 mm2 defect areas. MicroCT and histology were performed at 45 and 75d after surgery. While trephine surgeries were performed faster than piezoelectric (25.5 minutes vs 38.5 minutes), the rate of complications was much higher, with 36% of trephine rats taking 20 minutes to achieve hemostasis. Although the extent of new bone formation was similar between the two surgical groups, the piezoelectric technique resulted in 50% less variability. No additional new bone formation was observed from 45 to 75d in both techniques. Piezoelectric technique represents a refined and more reproducible technique for calvarial defect generation in comparison to classic trephine methods.

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.

Can early cranioplasty reduce the incidence of hydrocephalus after decompressive craniectomy? A meta-analysis

Background

Do alterations of cerebrospinal fluid dynamics secondary to decompressive craniectomy (DC) lead to hydrocephalus, and can this effect be mitigated by early cranioplasty (CP)? In this meta-analysis, we evaluated whether the timing of CP decreased the incidence of postoperative hydrocephalus.

Methods

We performed a systematic search of PubMed/MEDLINE, Scopus, and the Cochrane databases using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for English language articles (1990-2020). We included case series, case-control, and cohort studies, and clinical trials assessing the incidence of hydrocephalus in adult patients undergoing early CP (within 3 months) versus late CP (after 3 months) after DC.

Results

Eleven studies matched the inclusion criteria. The rate of postoperative hydrocephalus was not significantly different between the early (=96/1063; 9.03%) and late CP (=65/966; 6.72%) group (P = 0.09). Only in the three studies specifically reporting on the rate of hydrocephalus after DC performed to address traumatic brain injury (TBI) alone was there a significantly lower incidence of hydrocephalus with early CP (P = 0.01).

Conclusion

Early CP (within 90 days) after DC performed in TBI patients alone was associated with a lower incidence of hydrocephalus. However, this finding was not corroborated in the remaining eight studies involving CP for pathology exclusive of TBI.

Outcomes of Cranioplasty from a Tertiary Hospital in a Developing Country

Introduction

Although cranioplasty (CP) is a straightforward procedure, it may result in a significant number of complications. These include infections, seizures, intracranial hematomas, and others. Many reports have stated that early CP is associated with higher complications; however, more recent articles have contradicted this opinion. We intend to share our experience and results on outcomes of CP from our university hospital.

Materials and Methods

This is a 3-year retrospective analysis of patients undergoing CP. Demographic profile, etiology of decompressive craniectomy (DC), DC-CP interval, operative details, complications, and follow-up data were analyzed. Correlation of complications with timing of CP and other factors was studied to look for statistical significance.

Results

A.

total of 93 cases were analyzed. The majority were traumatic and ischemic stroke etiologies. There were eight open/compound head injuries (HIs). Eleven were bilateral and the rest unilateral cases. The mean and median CP interval were 8.5 weeks (range 4-28 weeks) and 8 weeks, respectively. All patients received 48 h to up to 5 days of postoperative antibiotics. Ten complications (10.7%) were noted (including one death). Poor Glasgow Outcome Scale at CP was the only statistically significant factor associated with higher complication rates. There was no statistical difference with respect to gender, CP material, and etiology; however, early CP had slightly fewer complications.

Conclusion

Patients with poor neurological condition at the time of CP have a significantly higher risk of complications. Contrary to earlier reports, early CP (<12 weeks) was not associated with higher complications but rather fewer complications than delayed procedures. Adherence to a few simple steps may help reduce these complications.

Aseptic bone-flap resorption after cranioplasty - incidence and risk factors

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.

Complications in cranioplasty after decompressive craniectomy: timing of the intervention

Objective

To prevent complications following decompressive craniectomy (DC), such as sinking skin flap syndrome, studies suggested early cranioplasty (CP). However, several groups reported higher complication rates in early CP. We studied the clinical characteristics associated with complications in patients undergoing CP, with special emphasis on timing.

Methods

A single-center observational cohort study was performed, including all patients undergoing CP from 2006 to 2018, to identify predictors of complications.

Results

145 patients underwent CP: complications occurred in 33 (23%): 18 (12%) epi/subdural hemorrhage, 10 (7%) bone flap infection, 4 (3%) hygroma requiring drainage, and 1 (1%) post-CP hydrocephalus. On univariate analysis, acute subdural hematoma as etiology of DC, symptomatic cerebrospinal fluid (CSF) flow disturbance (hydrocephalus) prior to CP, and CP within three months after DC were associated with higher complication rates. On multivariate analysis, only acute subdural hematoma as etiology of DC (OR 7.5; 95% CI 1.9–29.5) and symptomatic CSF flow disturbance prior to CP (OR 2.9; 95% CI 1.1–7.9) were associated with higher complication rates. CP performed within three months after DC was not (OR 1.4; 95% CI 0.5–3.9). Pre-CP symptomatic CSF flow disturbance was the only variable associated with the occurrence of epi/subdural hemorrhage. (OR 3.8; 95% CI 1.6–9.0)

Conclusion

Cranioplasty has high complication rates, 23% in our cohort. Contrary to recent systematic reviews, early CP was associated with more complications (41%), explained by the higher incidence of pre-CP CSF flow disturbance and acute subdural hematoma as etiology of DC. CP in such patients should therefore be performed with highest caution.

An investigation of factors associated with the development of postoperative bone flap infection following decompressive craniectomy and subsequent cranioplasty

OBJECTIVE

After a decompressive craniectomy (DC), a cranioplasty (CP) is often performed in order to improve neurosurgical outcome and cerebral blood circulation. But even though the performance of a CP subsequent to a DC has become routine medical practice, patients can in fact develop many complications from the surgery that could prolong hospitalization and lead to unfavorable prognoses. This study investigates one of the most frequent complications, bone flap infection, in order to identify prognostic factors of its development.

PATIENTS AND METHODS

In this single-center study, we have retrospectively examined 329 CPs performed between 2002 and 2017. Multiple categorical and metric parameters (e.g., timing of CP, bone flap material, specific laboratory signs of infection and reason for DC) were analyzed applying unadjusted and multivariable testing.

RESULTS

Bone flap infection occurred in 24 patients (7.3%). A CP performed more than six months after a DC is associated with a significantly increased risk of infection (OR = 0.308 [0.118; 0.803], p = 0.016). However, with CPs performed after twelve months, the incidence decreases, but without provable statistical impact. In addition, bone flap infection is strongly related to the neurological outcome and the material used for the skull implant, with the use of synthetic bone flaps leading to a marked increase in the rate of infection (p < 0.001).

CONCLUSIONS

This study supports the hypothesis that the risk of infection is higher the longer the elapsed time between DC and CP, especially if more than six months. Based on our results, the best DC-CP time frame for keeping the infection rate low is performing the CP within the first six months after the DC. In the event that the CP cannot be performed within the first six months, a CP performed twelve months or more after the DC seems to have a favorable outcome as well.

[Modern aspects of reconstructive surgery of skull defects]

The aim of this study is to systematize the modern methods used for reconstruction of extensive and complex skull defects. Special attention is paid to computer technologies, including 3D imaging and CAD/CAM. Laser-based stereolithography is thoroughly reviewed among other additive technologies. We present our view of the problem associated with proper timing of cranioplasty and choice of materials for it. Complications of skull defect reconstruction are also discussed.

Long-Term Complications of Cranioplasty Using Stored Autologous Bone Graft, Three-Dimensional Polymethyl Methacrylate, or Titanium Mesh After Decompressive Craniectomy: A Single-Center Experience After 596 Procedures

OBJECTIVE

Cranioplasty is a technically simple procedure intended to repair defects of the skull to provide protection after craniectomy, improve functional outcomes, and restore cosmesis. Several materials have been used for the restoration of skull defects, including autologous bone grafts (AGs), polymethyl methacrylate (PMMA) flaps, and titanium mesh (T-mesh). However, the long-term results of cranioplasty after use of these materials are controversial.

METHODS

Medical records of 596 patients who underwent cranioplasty at our medical center between 2009 and 2015 with at least 2.5 years of follow-up were retrospectively reviewed. Patients were classified into 3 groups according to the materials used: AG, three-dimensional PMMA, and T-mesh. Demographic and clinical characteristics and postoperative complications were analyzed.

RESULTS

Cranioplasty with AG had the highest bone flap depression rate (4.9%; P = 0.02) and was associated with a 26% long-term bone flap resorption. Younger age was a risk factor for bone flap resorption. T-mesh had a higher risk of postoperative skin erosion and bone exposure (17%; P = 0.004). Patients with diabetes, previous craniotomy, or hydrocephalus showed a higher risk of postoperative skin erosion. PMMA was associated with the highest rate of postoperative infection (14.4% <3 months, 28.1% >3 months; P < 0.05), and previous craniotomy may increase the infection risk after cranioplasty with PMMA.

CONCLUSIONS

Complications after cranioplasty are high, and the various types of cranioplasty materials used are associated with different complications. Surgeons need to be aware of these potential complications and should choose the appropriate material for each individual patient.

Incidence and Risk Factors for Skull Implant Displacement After Cranial Surgery

OBJECTIVE

Various complications that can occur during and after cranial surgery have been investigated extensively. One of the less frequent complications has thus far received little attention, however: displacement of the skull implant after craniotomy or craniectomy. The purpose of this study is to identify prognostic factors for the development of skull implant displacement (SID).

METHODS

In this study, 9087 cranial surgeries performed between 2002 and 2017 were retrospectively examined for the occurrence of SID. Because a first analysis of the investigated data revealed that a notable number of SIDs occurred after a cranioplasty (CP) performed after a decompressive craniectomy (DC), we focused our investigation on these cases. A total of 669 DCs and 329 subsequently performed CPs were analyzed. Several factors were analyzed unadjusted as possible factors influencing the risk for the development of SID.

RESULTS

A total of 13 implant dislocations occurred after CP (3.95%). Fixation technique is the only factor that seems to have had a significant influence, specifically not using miniplates as the fixation technique, which was associated with a higher risk of SID (P = 0.043). However, if fixation techniques are distinguished in more detail, no significant advantage of the miniplates over titanium clamps can be proven (P = 0.123). None of the remaining observed factors showed a statistically provable impact in our data.

CONCLUSIONS

A notable number of SIDs only occur after CPs that follow a DC. An advantage in successful placement was observed when fixation of the skull implant during cranioplasty was performed using miniplates.

Sinking Skin Flap Syndrome or Syndrome of the Trephined: A Report of Two Cases

Decompressive craniectomy (DC) is commonly performed in patients with intracranial hypertension or brain edema due to traumatic brain injury. Infrequently, neurologic deteriorations accompanied by sunken scalp may occur after DC. We report two patients with traumatic subdural hemorrhage who had neurologic deteriorations accompanied by sunken scalp after DC. Neurologic function improved dramatically in both patients after cranioplasty. Monitoring for neurologic deterioration after craniectomy is advised. For patients showing neurologic deficit with a sunken scalp, early cranioplasty should be considered.

A case series of early and late cranioplasty-comparison of surgical outcomes

BACKGROUND

Cranioplasty is an increasingly common procedure performed in neurosurgical centres following a decompressive craniectomy (DC), however, timing of the procedure varies greatly.

OBJECTIVES

The aim of this study is to compare the surgical outcomes of an early compared to a late cranioplasty procedure.

METHODS

Ninety adult patients who underwent a prosthetic cranioplasty between 2014 and 2017 were studied retrospectively. Timing of operation, perioperative complications and length of stay were assessed. Early and late cranioplasties were defined as less or more than 3 months since craniectomy respectively.

RESULTS

Of the 90 patients, 73% received a late cranioplasty and 27% received an early cranioplasty. The median interval between craniectomy and cranioplasty was 13 months [range 3-84] in late group versus 54 days [range 33-90] in early group. Twenty-two patients in the early group (91%) received a cranioplasty during the original admission while undergoing rehabilitation. Complications were seen in 25 patients (28%). These included wound or cranioplasty infection, hydrocephalus, symptomatic pneumocephalus, post-operative haematoma and cosmetic issues. The complication rate was 21% in the early group and 30% in the late group (P value 0.46). There was no significant difference in the rate of infection or hydrocephalus between the two groups. Length of stay was not significantly increased in patients who received an early cranioplasty during their initial admission (median length of stay 77 days versus 63 days, P value 0.28).

CONCLUSION

We have demonstrated the potential for early cranioplasty to be a safe and viable option, when compared to delayed cranioplasty.

Timing for cranioplasty to improve neurological outcome: A systematic review

INTRODUCTION

Cranioplasty is a surgical technique applied for the reconstruction of the skullcap removed during decompressive craniectomy (DC). Cranioplasty improves rehabilitation from a motor and cognitive perspective. However, it may increase the possibility of postoperative complications, such as seizures and infections. Timing of cranioplasty is therefore crucial even though literature is controversial. In this study, we compared motor and cognitive effects of early cranioplasty after DC and assess the optimal timing to perform it.

METHODS

A literature research was conducted in PubMed, Web of Science, and Cochrane Library databases. We selected studies including at least one of the following test: Mini-Mental State Examination, Rey Auditory Verbal Learning Test immediate and 30-min delayed recall, Digit Span Test, Glasgow Coma Scale, Glasgow Outcome Scale, Coma Recovery Scale-Revised, Level of Cognitive Functioning Scale, Functional Independence Measure, and Barthel Index.

RESULTS

Six articles and two systematic reviews were included in the present study. Analysis of changes in pre- and postcranioplasty scores showed that an early procedure (within 90 days from decompressive craniectomy) is more effective in improving motor functions (standardized mean difference [SMD] = 0.51 [0.05; 0.97], p-value = 0.03), whereas an early procedure did not significantly improve neither MMSE score (SMD = 0.06 [-0.49; 0.61], p-value = 0.83) nor memory functions (SMD = -0.63 [-0.97; -0.28], p-value < 0.001). No statistical significance emerged when we compared studies according to the timing from DC.

CONCLUSIONS

It is believed that cranioplasty performed from 3 to 6 months after DC may significantly improve both motor and cognitive recovery.

Early or late cranioplasty following decompressive craniotomy for traumatic brain injury: A systematic review and meta-analysis

Objective To evaluate the effectiveness of early (<3 months) cranioplasty (CP) and late CP (>3 months) on post-operative complications in patients receiving decompressive craniotomy (DC) for traumatic brain injury (TBI). Methods The Cochrane Library, PubMed and EMBASE databases were systematically searched for studies published prior to May 21, 2017. A meta-analysis examined post-operative overall complication rates, infection rates, subdural fluid collection and operating times according to early and late CP. Results Of the initial 1675 references, five studies, all cohort, involving a total of 413 patients, were selected for the review. There was no difference between early and late CP in post-operative overall complication rate (RR=0.68, 95%CI [0.36, 1.29]) and the post-operative infection rate (RR=0.50, 95%CI [0.20, 1.24]) in patients receiving DC for TBI. However, there was a significant difference in post-operative subdural effusion (RR=0.24, 95%CI [0.07, 0.78]) and mean operative time (mean difference = -33.02 min, 95%CI [-48.19, -17.84]) both in favour of early CP. Conclusions No differences were found between early and late CP in post-operative overall complications and procedural related infections in patients receiving DC for TBI, but early CP reduced the complication of subdural effusion and the mean operating time. These findings need to be confirmed by large, randomised controlled trials.

How Early Can We Perform Cranioplasty for Traumatic Brain injury After Decompressive Craniectomy? A Retrospective Multicenter Study

OBJECTIVE

Decompressive craniectomy (DC) is used to treat intractable intracranial hypertension after severe traumatic brain injury (TBI). Cranioplasty (CP) is typically performed weeks or months later. However, the optimal timing for CP is unknown. We aimed to determine the earliest possible time point for CP.

METHODS

We retrospectively reviewed brain computed tomography images from 159 patients who underwent CP after DC for TBI at 3 hospitals. We determined the earliest possible day for CP by reviewing the resolution of intracranial pressure in serial brain computed tomography images between DC and CP. The early CP group was defined as the group within the earliest possible timing of CP; other cases constituted the late CP group. We compared complications and the Glasgow Outcome Scale scores at 6 months between groups.

RESULTS

The mean initial Glasgow Coma Scale score was 8.33 ± 3.46. The time interval between DC and CP was 94.75 ± 143.98 days. The earliest possible timing for CP was determined to be 34.60 ± 34.36 days after DC. The incidence of complications did not differ significantly between groups, except for ventriculomegaly, which occurred more frequently in the late CP group (P = 0.026). Predictors of good outcome were revision because of infection, preoperative epidural hematoma, early cranioplasty, and no ventriculomegaly after DC.

CONCLUSIONS

CP can be performed at around 34 days after DC for TBI. Ventriculomegaly occurred less frequently and the 6-month Glasgow Outcome Scale score was better in the early CP group than in the late CP group.

The safety of simultaneous cranioplasty and shunt implantation

BACKGROUND

A large cranial defect combined with hydrocephalus is a frequent sequela of decompressive craniectomy (DC) performed to treat malignant intracranial hypertension. Currently, many neurosurgeons perform simultaneous cranioplasty and shunt implantation on such patients, but the safety of this combined procedure remains controversial.

METHODS

We retrospectively evaluated 58 patients treated via cranioplasty and shunt implantation after DC. Twenty patients underwent simultaneous procedures (simultaneous operation group) and 38 underwent staged procedures (staged operation group). We collected and analysed demographic data, information on disease histories, and clinical findings.

RESULTS

The overall complication rate was 19%. The two groups did not significantly differ regarding the all-complication (30% vs. 13%), bleeding complication (0% vs. 5%), or treatment failure (15% vs. 3%) rates. However, the rate of surgical site infection/incision healing problems (25% vs. 3%) and the re-operation rate (20% vs. 3%) were significantly higher in the simultaneous operation group.

CONCLUSION

Patients undergoing simultaneous cranioplasty/shunt implantation may be at a higher risk of infectious complications than those undergoing staged operations.

Incidence of Postoperative Hematomas Requiring Surgical Treatment in Neurosurgery: A Retrospective Observational Study

OBJECTIVE

We aimed to characterize the occurrence of postoperative hematoma (POH) after neurosurgery overall and according to procedure type and describe the prevalence of possible confounders.

METHODS

Patient data between 2010 and 2012 at the Department of Neurosurgery in Helsinki University Hospital were retrospectively analyzed. A data search was performed according to the type of surgery including craniotomies; shunt procedures, spine surgery, and spinal cord stimulator implantation. We analyzed basic preoperative characteristics, as well as data about the initial intervention, perioperative period, revision operation and neurologic recovery (after craniotomy only).

RESULTS

The overall incidence of POH requiring reoperation was 0.6% (n = 56/8783) to 0.6% (n = 26/4726) after craniotomy, 0% (n = 0/928) after shunting procedure, 1.1% (n = 30/2870) after spine surgery, and 0% (n = 0/259) after implantation of a spinal cord stimulator. Craniotomy types with higher POH incidence were decompressive craniectomy (7.9%, n = 7/89), cranioplasty (3.6%, n = 4/112), bypass surgery (1.7%, n = 1/60), and epidural hematoma evacuation (1.6%, n = 1/64). After spinal surgery, POH was observed in 1.1% of cervical and 2.1% of thoracolumbar operations, whereas 46.7% were multilevel procedures. 64.3% of patients with POH and 84.6% of patients undergoing craniotomy had postoperative hypertension (systolic blood pressure >160 mm Hg or lower if indicated). Poor outcome (Glasgow Outcome Scale score 1-3), whereas death at 6 months after craniotomy was detected in 40.9% and 21.7%. respectively, of patients with POH who underwent craniotomy.

CONCLUSIONS

POH after neurosurgery was rare in this series but was associated with poor outcome. Identification of risk factors of bleeding, and avoiding them, if possible, might decrease the incidence of POH.