Predictors of cranioplasty complications in stroke and trauma patients

Flap Design for Cranial Reconstruction: An Analysis of Craniectomy and Cranioplasty Incisions

Background

The surgical approach for cranial reconstruction is influenced by the presence of pre-existing scar tissue. Scars that lie within the vicinity of cranial defect require modification.

Purpose

The present study was conducted to analyse co-relation between craniectomy scar and cranioplasty incision.

Materials and Methods

A retrospective evaluation of 70 patients who were divided into three groups based on location of cranioplasty incision line was done. In group I, incision was located parallel and outside the scar; group II, incision was located over the scar; and group III, mixed and criss-cross incision was present. The primary outcome variable of interest was to analyse co-relation between craniectomy and cranioplasty incisions.

Results

There were 45 cases of group I, 15 cases of group II and 10 cases of group III. Thirty-three patients had defect on left side, 26 had on right side, and 10 had bifrontal defect. No significant association was noted between the site and cranioplasty incision (Chi2 = 9.155, p = 0.433 and likelihood ratio = 9.487, p = 0.394).

Conclusion

Well-vascularized broad-based scalp flap that provides adequate exposure and located on healthy bone irrespective of pre-existing craniectomy scar forms the mainstay of successful cranial reconstruction.

Earlier cranioplasty following posttraumatic craniectomy is associated with better neurological outcomes at one-year follow-up: a two-centre retrospective cohort study

PURPOSE

Cranioplasty (CP) after decompressive craniectomy (DC) is routinely performed for reconstructive purposes and improves rehabilitation. However, the optimal timing of CP remains controversial. This study aimed to assess differences in clinical outcomes following different timings of CP in patients with traumatic brain injury.

MATERIALS AND METHODS

Patients with traumatic brain injury who underwent CP after DC in Zhongnan Hospital of Wuhan University from 1 January 2010 to 1 May 2017, and in Affiliated Hospital of Guizhou Medical University from 1 January 2015, to 1 May 2017, were retrospectively reviewed. According to the timing of CP, patients were divided into an 'early group' (3-6 months) and a 'late group' (6-12 months). The clinical characteristics of patients and postoperative complications occurred within 1-year follow-up were analysed. The neurological function was assessed with Barthel Index (BI).

RESULTS

A total of 100 patients (58 cases in early group and 42 cases in late group) were included. The median interval between DC and CP was 135 days and 225 days in the early and late CP groups, respectively. The overall complication rate after CP was 16%, and no significant difference in complication rate was observed between the early and late CP groups (17.2% vs.14.3%, p = 0.69). The neurological function was improved in early CP group (pre-CP 85.77 ± 11.61 vs. post-CP 95.34 ± 9.02, p < 0.001, but not in late CP group (pre-CP 82.74 ± 22.82 vs. post-CP 88.93 ± 22.86, p = 0.22). In addition, a significantly higher proportion of patients in the early CP group showed neurological functional improvement in comparison with the late CP group (early vs. late: 74.1% vs. 57.1%, p = 0.04). Multivariate analysis further demonstrated that the timing of CP is an independent predictor for neurological outcomes (OR = 0.32, 95% CI 0.13-0.82, p = 0.02).

CONCLUSION

Early CP (3-6 months) following posttraumatic DC was associated with better neurological outcomes than late CP (>6 months).

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..

Recent Updates on Controversies in Decompressive Craniectomy and Cranioplasty: Physiological Effect, Indication, Complication, and Management

Decompressive craniectomy (DCE) and cranioplasty (CP) are surgical procedures used to manage elevated intracranial pressure (ICP) in various clinical scenarios, including ischemic stroke, hemorrhagic stroke, and traumatic brain injury. The physiological changes following DCE, such as cerebral blood flow, perfusion, brain tissue oxygenation, and autoregulation, are essential for understanding the benefits and limitations of these procedures. A comprehensive literature search was conducted to systematically review the recent updates in DCE and CP, focusing on the fundamentals of DCE for ICP reduction, indications for DCE, optimal sizes and timing for DCE and CP, the syndrome of trephined, and the debate on suboccipital CP. The review highlights the need for further research on hemodynamic and metabolic indicators following DCE, particularly in relation to the pressure reactivity index. It provides recommendations for early CP within three months of controlling increased ICP to facilitate neurological recovery. Additionally, the review emphasizes the importance of considering suboccipital CP in patients with persistent headaches, cerebrospinal fluid leakage, or cerebellar sag after suboccipital craniectomy. A better understanding of the physiological effects, indications, complications, and management strategies for DCE and CP to control elevated ICP will help optimize patient outcomes and improve the overall effectiveness of these procedures.

Superficial temporal artery injury and delayed post-cranioplasty infection

OBJECTIVE

Complications after cranioplasty after decompressive craniectomy (DC) have been reported to be as high as 40%. The superficial temporal artery (STA) is at substantial risk for injury in standard reverse question-mark incisions that are typically used for unilateral DC. The authors hypothesize that STA injury during craniectomy predisposes patients to post-cranioplasty surgical site infection (SSI) and/or wound complication.

METHODS

A retrospective study of all patients at a single institution who underwent cranioplasty after decompressive craniectomy and who underwent imaging of the head (computed tomography angiogram, magnetic resonance imaging with intravenous contrast, or diagnostic cerebral angiography) for any indication between the two procedures was undertaken. The degree of STA injury was classified and univariate statistics were used to compare groups.

RESULTS

Fifty-four patients met inclusion criteria. Thirty-three patients (61%) had evidence of complete or partial STA injury on pre-cranioplasty imaging. Nine patients (16.7%) developed either an SSI or wound complication after cranioplasty and, among these, four (7.4%) experienced delayed (>2 weeks from cranioplasty) complications. Seven of 9 patients required surgical debridement and cranioplasty explant. There was a stepwise but non-significant increase in post-cranioplasty SSI (STA present: 10%, STA partial injury: 17%, STA complete injury: 24%, P=0.53) and delayed post-cranioplasty SSI (STA present: 0%, STA partial injury: 8%, STA complete injury: 14%, P=0.26).

CONCLUSIONS

There is a notable but statistically non-significant trend toward increased rates of SSI in patients with complete or partial STA injury during craniectomy.

Complications of Different Types of Cranioplasty and Identification of Risk Factors Associated with Cranioplasty at a Tertiary Care Centre: A Prospective Observational Study

Objective Decompressive craniectomy (DC) is an urgent procedure which is done to decrease intracranial pressure. A study of the complications would suggest measures to improve the care. This study was focused on analyzing the complications after cranioplasty (CP) and to identify risk factors that may be associated with the failure of the procedure.

Method: This study was conducted over 41 months at level-1 trauma center and medical college. It included patients undergoing CP for a defect arising out of previous DC or inability to replace the bone flap (Glasgow Coma Scale > 13, size > 5 cm, without surgical site infection). All patients underwent CT imaging before and after the procedure. The CP technique largely depended on the patients, based on the cost of prosthesis and availability.

Result: Hundred patients were included in the study. Postoperatively, total 22 patients suffered complications of which few had more than one complication. Titanium implant appeared to be a better implant, with no complication (p < 0.05). Complication was common in younger age group, chemically cured PMMA (polymethyl methacrylate) and ethylene oxide) sterilized bone flap). Complications were higher among patients with multiple comorbidity and stroke patients.

Conclusion: Titanium flap had no complication and in case of autologous abdominal subcutaneous flap, apart from bone flap absorption, patients had no major complication. Therefore, both implants are preferred implants for CP. Heat-cured PMMA can be used in case of nonavailability of a better option, as it is economical feasible and can be molded at any dental lab.

Outcomes of Cranioplasty: A Single-Center Experience

Background Cranioplasty (CP) is a common cranial reconstructive procedure. It is performed after craniectomy due to various causes such as relieving increased intracranial pressure, infection, and tumor infiltration. Although CP is an easy procedure, it is associated with a high rate of complications. We aimed to retrospectively investigate the outcomes of CP at the King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Jeddah (KAMC-J). Methods This is a retrospective observational study that included all patients who had CP (first time or redo) at KAMC-J from 1st January 2010 to 31st December 2020. Patients with congenital cranial malformation were excluded.  Result A total of 68 patients underwent CP. Of those, 23 (34%) had complications. The most common complication was infection (10.3%). Twelve of the 23 patients had major complications that necessitated reoperation. Of those 12, six underwent redo CP; three out of these six patients had further complications which were also managed surgically. On bivariate analysis, cranial defects over 50 cm² were associated with a higher rate of both infection and hydrocephalus (p=0.018) while the frontal site was associated with a higher rate of infection (p=0.014). Moreover, traumatic brain injury as an etiology was exclusively associated with post-cranioplasty hydrocephalus (p=0.03).  Conclusion Patients undergoing CP after craniectomy are prone to a considerably high rate of adverse outcomes. The overall rate of complications in this study was 34%, with an infection rate of 10.3% and a 1.5% mortality rate. Consistent with other studies, larger cranial defects as well as frontal sites have a higher rate of infection.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Post-traumatic hydrocephalus may be associated with autologous cranioplasty failure, independent of ventriculoperitoneal shunt placement: a retrospective analysis

PURPOSE

Decompressive craniectomy (DC) is a common procedure used for the treatment of intracranial hypertension. Once brain swelling has subsided, a cranioplasty is performed to restore cosmesis and protection to the brain. While using the patient's autologous bone flap is often the first choice in cranioplasty, this procedure is frequently complicated by bone flap resorption and infection. This study seeks to identify predictors of autologous cranioplasty failure.

METHODS

A retrospective analysis was conducted on patients who underwent decompressive craniectomy and autologous cranioplasty. Patient demographics and factors related to both surgeries and failure rates were recorded from patient records. Logistic regressions were conducted to determine which factors were implicated in autologous cranioplasty failure.

RESULTS

In our cohort, 127 patients underwent autologous cranioplasty. Overall, 18 (14.2%) patients experienced autologous cranioplasty failure. Regression analysis identified development of post-traumatic hydrocephalus (PTH) following DC (OR: 3.26, p = 0.043), presence of neurological deficits following DC (OR: 4.88, p = 0.025), and reoperation prior to CP (OR 3.0, p = 0.049) as significant predictors of autologous cranioplasty failure. Of the 16 patients who developed PTH following DC, 9 received a VP shunt. The rate of flap failure was similar across the 9 PTH patients who received a shunt and the 7 PTH patients who did not receive a shunt (33% vs. 57% failure rate, respectively, p = 0.341).

CONCLUSION

Autologous cranioplasty is a reasonably successful procedure with a flap failure rate of 14.2%. We identified PTH, persistent neurological deficits, and reoperation prior to cranioplasty as significant predictors of autologous cranioplasty failure. Interestingly, the presence of VP shunt did not impact the odds of flap failure.

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.

Systematic Review of Syndrome of the Trephined and Reconstructive Implications

Syndrome of the trephined (SoT) is a severe complication following decompressive craniectomy resulting in neurological decline which can progress to aphasia, catatonia, and even death. While cranioplasty can reverse neurological symptoms of SoT, awareness of SoT is poor outside of the neurosurgery community. The authors performed a systematic review of the literature on SoT with a focus on reconstructive implications. Search terms "syndrome of the trephined" and "sunken flap syndrome" were applied to PubMed to identify primary studies through October 2021. Full-text review yielded 11 articles discussing SoT and reconstructive techniques or implications with 56 patients undergoing cranial reconstruction. Average age of the patients was 41.8±9.5 years. Sixty-three percent of the patients were male. The most common indication for craniectomy was traumatic brain injury (43%), followed by tumor resection (23%), intracerebral hemorrhage (11%), and aneurysmal subarachnoid hemorrhage (2%). Patients most commonly suffered from motor deficits (52%), decreased wakefulness (30%), depression or anxiety (21%), speech deficits (16%), headache (16%), and cognitive difficulties (2%). Time until presentation of symptoms following decompression was 4.4±8.9 months. Patients typically underwent cranioplasty with polyetheretherketone (48%), titanium mesh (21%), split thickness calvarial bone (16%), full thickness calvarial bone (14%), or split thickness rib graft (4%). Eight percent of patients required free tissue transfer for soft tissue coverage. Traumatic Brain Injury (TBI) was a risk factor for development of SoT when adjusting for age and sex (odds ratio: 8.2, 95% confidence interval: 1.2-8.9). No difference significant difference was observed between length until initial improvement of neurological symptoms following autologous versus allograft reconstruction (P=0.47). SoT can be a neurologically devastating complication of decompressive craniectomy which can resolve following urgent cranioplasty. Familiarity with this syndrome and its reconstructive implications is critical for the plastic surgery provider, who may be called upon to assist with these urgent cases.

A multicenter cohort study of early complications after cranioplasty: results of the German Cranial Reconstruction Registry

OBJECTIVE

Cranioplasty (CP) is a crucial procedure after decompressive craniectomy and has a significant impact on neurological improvement. Although CP is considered a standard neurosurgical procedure, inconsistent data on surgery-related complications after CP are available. To address this topic, the authors analyzed 502 patients in a prospective multicenter database (German Cranial Reconstruction Registry) with regard to early surgery-related complications.

METHODS

Early complications within 30 days, medical history, mortality rates, and neurological outcome at discharge according to the modified Rankin Scale (mRS) were evaluated. The primary endpoint was death or surgical revision within the first 30 days after CP. Independent factors for the occurrence of complications with or without surgical revision were identified using a logistic regression model.

RESULTS

Traumatic brain injury (TBI) and ischemic stroke were the most common underlying diagnoses that required CP. In 230 patients (45.8%), an autologous bone flap was utilized for CP; the most common engineered materials were titanium (80 patients [15.9%]), polyetheretherketone (57 [11.4%]), and polymethylmethacrylate (57 [11.4%]). Surgical revision was necessary in 45 patients (9.0%), and the overall mortality rate was 0.8% (4 patients). The cause of death was related to ischemia in 2 patients, diffuse intraparenchymal hemorrhage in 1 patient, and cardiac complications in 1 patient. The most frequent causes of surgical revision were epidural hematoma (40.0% of all revisions), new hydrocephalus (22.0%), and subdural hematoma (13.3%). Preoperatively increased mRS score (OR 1.46, 95% CI 1.08-1.97, p = 0.014) and American Society of Anesthesiologists Physical Status Classification System score (OR 2.89, 95% CI 1.42-5.89, p = 0.003) were independent predictors of surgical revision. Ischemic stroke, as the underlying diagnosis, was associated with a minor rate of revisions compared with TBI (OR 0.18, 95% CI 0.06-0.57, p = 0.004).

CONCLUSIONS

The authors have presented class II evidence-based data on surgery-related complications after CP and have identified specific preexisting risk factors. These results may provide additional guidance for optimized treatment of these patients.

Neurological update: consult the neurosurgical oracle for a standard operating procedure

Standard operating procedures (SOPs) contain general instructions and principles to standardize care, to improve effective and safe healthcare. Developing new, or updating current, SOPs is, however, challenging in fields where high-level evidence is limited. Still, SOPs alone have been shown to result in less complications. In this narrative review, we describe the process of creating a consensus-based SOP that is pragmatic for clinical practice since it can be created regardless of the current level of evidence. Through live audience engagement platforms, a group of experts will be able to both anonymously respond to a created questionnaire, and (subsequently) discuss the results within the same meeting. This modified Digital Delphi method as described here can be used as a tool toward consensus-based healthcare.

Surface Area of Decompressive Craniectomy Predicts Bone Flap Failure after Autologous Cranioplasty: A Radiographic Cohort Study

Skull bone graft failure is a potential complication of autologous cranioplasty after decompressive craniectomy (DC). Our objective was to investigate the association of graft size with subsequent bone graft failure after autologous cranioplasty. This single-center retrospective cohort study included patients age ≥18 years who underwent primary autologous cranioplasty between 2010 and 2017. The primary outcome was bone flap failure requiring graft removal. Demographic, clinical, and radiographic factors were recorded; three-dimensional (3D) reconstructive imaging was used to perform accurate measurements. Univariate and multi-variate regression analysis were performed to identify risk factors for the primary outcome. Of the 131 patients who underwent primary autologous cranioplasty, 25 (19.0%) underwent removal of the graft after identification of bone flap necrosis on computed tomography (CT); 16 (64%) of these were culture positive. The mean surface area of craniectomy defect was 128.5 cm² for patients with bone necrosis and 114.9 cm² for those without bone necrosis. Linear regression analysis demonstrated that size of craniectomy defect was independently associated with subsequent bone flap failure; logistic regression analysis demonstrated a defect area >125 cm² was independently associated with failure (odds ratio [OR] 3.29; confidence interval [CI]: 0.249-2.135). Patient- and operation-specific variables were not significant predictors of bone necrosis. Our results showed that increased size of antecedent DC is an independent risk factor for bone flap failure after autologous cranioplasty. Given these findings, clinicians should consider the increased potential of bone flap failure after autologous cranioplasty among patients whose initial DC was >125 cm².

The Materials Utilized in Cranial Reconstruction: Past, Current, and Future

BACKGROUND

Cranioplasty (CP) is associated with high complication rates compared to other common neurosurgical procedures. Several graft materials are used for CP, which may contribute to the high complication rates, but data in the literature regarding the influence of graft material on post-CP outcomes are inconsistent making it difficult to determine if, when, and to what extent the graft material impacts the rate of perioperative complications. There is an increased demand to identify and develop superior graft materials.

OBJECTIVE

To review and compare the indications, risks, complications, and patient results associated with the use of different graft materials for cranial reconstructions.

DESIGN

A search through EBSCOhost was conducted using the keywords "craniectomy" or "decompressive craniectomy," "cranioplasty," and "materials." The search was limited to literature published in the English language from 2005 until the present. Ultimately, 69 articles were included in this review. Due to the heterogeneity of the study populations, results, statistical analyses, and collecting methods, no statistical analyses could be performed.

CONCLUSIONS

Several graft materials have been adapted for use in cranial reconstructions with inconsistent results making it unclear if or when one material may be indicated over others. Advances in computer-aided design have led to improved patient-specific implants, but the ideal graft material is still being sought after in ongoing research efforts. Reviewing materials currently available, as well as those in clinical trials, is important to identify the limitations associated with different implants and to guide future research.

Bone flap management strategies for postcraniotomy surgical site infection

Background:

Surgical site infection (SSI) after a craniotomy is traditionally treated with wound debridement and disposal of the bone flap, followed by intravenous antibiotics. The goal of this study is to evaluate the safety of replacing the bone flap or performing immediate titanium cranioplasty.

Methods:

All craniotomies at single center between 2008 and 2020 were examined to identify 35 patients with postoperative SSI. Patients were grouped by bone flap management: craniectomy (22 patients), bone flap replacement (seven patients), and titanium cranioplasty (six patients). Retrospective chart review was performed to identify patient age, gender, index surgery indication and duration, diffusion restriction on MRI, presence of gross purulence, bacteria cultured, sinus involvement, implants used during surgery, and antibiotic prophylaxis/ treatment. These variables were compared to future infection recurrence and wound breakdown.

Results:

There was no significant difference in infection recurrence or future wound breakdown among the three bone flap management groups (P = 0.21, P = 0.25). None of the variables investigated had any significant relation to infection recurrence when all patients were included in the analysis. However, when only the bone flap replacement group was analyzed, there was significantly higher infection recurrence when there was frank purulence present (P = 0.048).

Conclusion:

Replacing the bone flap or performing an immediate titanium cranioplasty is safe alternatives to discarding the bone flap after postoperative craniotomy SSI. When there is gross purulence present, caution should be used in replacing the bone flap, as infection recurrence is significantly higher in this subgroup of patients.

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.

Low-Cost Customized Cranioplasty with Polymethyl Methacrylate Using 3D Printer Generated Mold: An Institutional Experience and Review of Literature

Background Cranioplasty is performed to repair skull defects and to restore normal skull anatomy. Optimal reconstruction remains a topic of debate. Autologous bone flap is the standard option but it may not be available due to traumatic bone fractures, bone infection, and resorption. In this article, the authors presented their experience with prefabrication of precise and low-cost polymethyl methacrylate (PMMA) mold using three-dimensional (3D) digital printing.

Materials and Methods A total of 30 patients underwent cranioplasty between March 2017 and September 2019 at Sawai Man Singh Medical College Jaipur, India. Preoperative data included diagnosis for which decompressive craniectomy was done and Glasgow coma scale score. Intraoperative data included operating time. Postoperative data included cosmetic outcome in the form of cranial contour and margins, complications such as infection, seroma, implant failure, wound dehiscence, and hematoma.

Results Patient age at cranioplasty ranged from 12 to 63 years with a mean age of 36.7 years. The mean operating time was 151.6 minutes (range 130–190 minutes). The mean follow-up period was 8 months (range 6–13 months). Postoperative wound dehiscence developed in one case (3.3%). Cranial contour and approximation of the margins were excellent and aesthetic appearance improved in all patients.

Conclusion Low-cost PMMA implant made by digital 3D printer mold is associated with reconstruction of the deformed skull contour giving satisfactory results to the patient and his family members, at a low cost compared with other commercially available implants. This technique could be a breakthrough in cranioplasty.

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.

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

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

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

Background

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

Methods

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

Results

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

Conclusions

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

Dermointegration in the exposed titanium cranioplasty: a possible protective phenomenon

Implant exposure is a known complication of titanium mesh cranioplasty and is usually managed by implant removal and/or exchange. We describe a case of exposed titanium mesh cranioplasty which was managed with implant exchange and bipedicled flap coverage, and showcase an interesting phenomenon of full-thickness skin present beneath the exposed mesh. This was confirmed on histopathology, which showed the presence of dermal appendages including pilosebaceous units and eccrine glands. We postulate that the mechanism behind this phenomenon involves islands of viable skin ‘dropping’ between holes in the mesh and coalescing beneath the exposed implant, as suggested by histopathology findings of nodular protrusions and varying degrees of epidermal hyperplasia. This protects the underlying dura from external infection. We propose for this phenomenon to be called dermointegration. Our findings suggest that similar cases, particularly patients who are not fit for general anaesthesia, may potentially be managed with a more conservative approach.

The storage of skull bone flaps for autologous cranioplasty: literature review

The use of autologous bone flap for cranioplasty after decompressive craniectomy is a widely used strategy that allows alleviating health expenses. When the patient has recovered from the primary insult, the cranioplasty restores protection and cosmesis, recovering fluid dynamics and improving neurological status. During this time, the bone flap must be stored, but there is a lack of standardization of tissue banking practices for this aim. In this work, we have reviewed the literature on tissue processing and storage practices. Most of the published articles are focused from a strictly clinical and surgical point of view, paying less attention to issues related to tissue manipulation. When bone resorption is avoided and the risk of infection is controlled, the autograft represents the most efficient choice, with the lowest risk of complication. Otherwise, depending on the degree of involvement, the patient may have to undergo new surgery, assuming further risks and higher healthcare costs. Therefore, tissue banks must implement protocols to provide products with the highest possible clinical effectiveness, without compromising safety. With a centralised management of tissue banking practices there may be a more uniform approach, thus facilitating the standardization of procedures and guidelines.

Escalate and De-Escalate Therapies for Intracranial Pressure Control in Traumatic Brain Injury

Severe traumatic brain injury (TBI) is frequently associated with an elevation of intracranial pressure (ICP), followed by cerebral perfusion pressure (CPP) reduction. Invasive monitoring of ICP is recommended to guide a step-by-step “staircase approach” which aims to normalize ICP values and reduce the risks of secondary damage. However, if such monitoring is not available clinical examination and radiological criteria should be used. A major concern is how to taper the therapies employed for ICP control. The aim of this manuscript is to review the criteria for escalating and withdrawing therapies in TBI patients. Each step of the staircase approach carries a risk of adverse effects related to the duration of treatment. Tapering of barbiturates should start once ICP control has been achieved for at least 24 h, although a period of 2–12 days is often required. Administration of hyperosmolar fluids should be avoided if ICP is normal. Sedation should be reduced after at least 24 h of controlled ICP to allow neurological examination. Removal of invasive ICP monitoring is suggested after 72 h of normal ICP. For patients who have undergone surgical decompression, cranioplasty represents the final step, and an earlier cranioplasty (15–90 days after decompression) seems to reduce the rate of infection, seizures, and hydrocephalus.

Low-Cost Customized Cranioplasty with Polymethyl Methacrylate Using 3D Printer Generated Mold: An Institutional Experience and Review of Literature

Background Cranioplasty is performed to repair skull defects and to restore normal skull anatomy. Optimal reconstruction remains a topic of debate. Autologous bone flap is the standard option but it may not be available due to traumatic bone fractures, bone infection, and resorption. The authors present their experience with prefabrication of precise and low-cost polymethyl methacrylate (PMMA) mold using three-dimensional (3D) digital printing.

Methods A total of 30 patients underwent cranioplasty between March 2017 and September 2019 at Sawai Man Singh Medical College Jaipur, India. Preoperative data included diagnosis for which decompressive craniectomy was done and Glasgow coma scale score was observed. Intraoperative data included operating time. Postoperative data included cosmetic outcome in the form of cranial contour and margins, complications such as infection, seroma, implant failure, wound dehiscence, and hematoma.

Results Patient age at cranioplasty ranged from 12 to 63 years with a mean age of 36.7 years. The mean operating time was 151.6 minutes (range 130–190 minutes). The mean follow-up period was 8 months (range 6–13 months). Postoperative wound dehiscence developed in one case (3.3%). Cranial contour and approximation of the margins were excellent and aesthetic appearance improved in all patients.

Conclusion Low-cost PMMA implant made by digital 3D printer mold is associated with reconstruction of the deformed skull contour giving satisfactory results to the patient and his family members, at a low cost compared with other commercially available implants. This technique could be a breakthrough in cranioplasty.

Comparison of Postoperative Surgical-Site Infection and Symptomatic Intracranial Hemorrhage between Staged and Simultaneous Cranioplasty with Ventriculoperitoneal Shunt Placement: A Meta-Analysis

Objective

Consensus about the sequence of cranioplasty and ventriculoperitoneal shunt placement to reduce postoperative complications has not been established. This meta-analysis investigated and collated further evidence to determine whether staged cranioplasty with ventriculoperitoneal shunt placement would significantly reduce the risk of postoperative surgical-site infection (SSI) and symptomatic intracranial hemorrhage.

Methods

Two independent reviewers identified articles and extracted the data of patients who underwent cranioplasty and ventriculoperitoneal shunt placement from PubMed, Embase, and Cochrane Central Register of Controlled Trials. A random effects model was used to compare the complication rates using odd ratios (ORs) and 95% confidence intervals (CIs). A meta-regression analysis for traumatic brain injury (TBI) was additionally performed.

Results

Data from 7 studies with 391 patients were consecutively included. The meta-analysis revealed that staged surgery was significantly associated with lower rates of SSI after decompressive craniectomy (staged group vs. simultaneous group: 6.2% vs. 23.7%, OR: 2.72, 95% CI: 1.46–5.06, I²=2.4%, p=0.407). Pooled analysis did not indicate a statistically significant difference between the 2 groups for symptomatic intracranial hemorrhage (staged group vs. simultaneous group: 10.4% vs. 23.0%, OR: 1.66, 95% CI: 0.74–3.73, I²=0.0%, p=0.407). The meta-regression analysis did not indicate any modifying effect of TBI on postoperative SSI development (p=0.987).

Conclusion

This meta-analysis indicated that staged surgery is significantly associated with a lower rate of postoperative SSI as compared with simultaneous surgery, but there is no difference in symptomatic intracranial hemorrhage. Additionally, there is no modifying effect of TBI on SSI.

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.

Cranioplasty Following Decompressive Craniectomy

Cranioplasty (CP) after decompressive craniectomy (DC) for trauma is a neurosurgical procedure that aims to restore esthesis, improve cerebrospinal fluid (CSF) dynamics, and provide cerebral protection. In turn, this can facilitate neurological rehabilitation and potentially enhance neurological recovery. However, CP can be associated with significant morbidity. Multiple aspects of CP must be considered to optimize its outcomes. Those aspects range from the intricacies of the surgical dissection/reconstruction during the procedure of CP, the types of materials used for the reconstruction, as well as the timing of the CP in relation to the DC. This article is a narrative mini-review that discusses the current evidence base and suggests that no consensus has been reached about several issues, such as an agreement on the best material for use in CP, the appropriate timing of CP after DC, and the optimal management of hydrocephalus in patients who need cranial reconstruction. Moreover, the protocol-driven standards of care for traumatic brain injury (TBI) patients in high-resource settings are virtually out of reach for low-income countries, including those pertaining to CP. Thus, there is a need to design appropriate prospective studies to provide context-specific solid recommendations regarding this topic.

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.

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

Objectives

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

Patients and methods

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

Results

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

Conclusions

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

Postcranioplasty seizures following decompressive craniectomy and seizure prophylaxis: a retrospective analysis at a single institution

OBJECTIVE

Cranioplasty is a relatively simple and less invasive intervention, but it is associated with a high incidence of postoperative seizures. The incidence of, and the risk factors for, such seizures and the effect of prophylactic antiepileptic drugs (AEDs) have not been well studied. The authors' aim was to evaluate the risk factors that predispose patients to postcranioplasty seizures and to examine the role of seizure prophylaxis in cranioplasty.

METHODS

The records of patients who had undergone cranioplasty at the authors' medical center between 2009 and 2014 with at last 2 years of follow-up were retrospectively reviewed. Demographic and clinical characteristics, the occurrence of postoperative seizures, and postoperative complications were analyzed.

RESULTS

Among the 583 patients eligible for inclusion in the study, 247 had preexisting seizures or used AEDs before the cranioplasty and 336 had no seizures prior to cranioplasty. Of these 336 patients, 89 (26.5%) had new-onset seizures following cranioplasty. Prophylactic AEDs were administered to 56 patients for 1 week after cranioplasty. No early seizures occurred in these patients, and this finding was statistically significant (p = 0.012). Liver cirrhosis, intraoperative blood loss, and shunt-dependent hydrocephalus were risk factors for postcranioplasty seizures in the multivariable analysis.

CONCLUSIONS

Cranioplasty is associated with a high incidence of postoperative seizures. The prophylactic use of AEDs can reduce the occurrence of early seizures.

Early autologous cranioplasty: complications and identification of risk factors using virtual reality visualisation technique

Background: Cranioplasty (CP) of autologous bone flap after decompressive craniectomy (DC) is known to be associated with a high complication rate, particularly bone flap resorption (BFR). In a retrospective study, we used a novel virtual reality (VR) visualisation technique to identify and evaluate risk factors associated with CP.Method: Twenty-five patients underwent early autologous CP. All complications were recorded. Cranial computed tomography scans were visualised via the VR software to access the fitting accuracy of the bone flap (bone flap size, gap width at trepanation cutting edge, extent of osteoclastic extension).Results: An overall complication rate of 44% was seen, and BFR was the most common (36%). Only 'osteoclastic extension of trepanation' (p = .04) was a significant risk factor for BFR. The factors 'indication for DC' (p = .09) and 'size of bone flap' (p = .09) had a tendency towards influencing the rate of BFR, while 'age' (p = .68), 'time interval between DC and CP' (p = 1.00), and 'gap width' (p = .50) were not considered to influence the BFR rate.Conclusions: DC and subsequent CP is a complication-prone procedure. Therefore, it is relevant to identify and quantify probable risk factors for the most common complications, such as BFR. Here, we found that the extent of osteoclastic extension may impair the patient's healing process. Our investigation was made considerably easier by using the novel VR visualisation technique, which allows parallax free measurements of distances in 3D space.

The application of polyetheretherketone (PEEK) implants in cranioplasty

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

Evaluation of neurosurgical implant infection rates and associated pathogens: evidence from 1118 postoperative infections

OBJECTIVE

Various implanted materials are used in neurosurgery; however, there remains a lack of pooled data on infection rates (IRs) and infective bacteria over past decades. The goal of this study was to investigate implant infections in neurosurgical procedures in a longitudinal retrospective study and to evaluate the IRs of neurosurgically implanted materials and the distribution of pathogenic microorganisms.

METHODS

A systematic literature search was conducted using PubMed and Web of Science databases for the time period between 1968 and 2018. Neurosurgical implant infections were studied in 5 subgroups, including operations or diseases, implanted materials, bacteria, distribution by country, and time periods, which were obtained from the literature and statistically analyzed. In this meta-analysis, statistical heterogeneity across studies was tested by using p values and I2 values between studies of associated pathogens. Egger’s test was used for assessing symmetries of funnel plots with Stata 11.0 software. Methodological quality was assessed to judge the risk of bias according to the Cochrane Handbook.

RESULTS

A total of 22,971 patients from 227 articles satisfied the study’s eligibility criteria. Of these, 1118 cases of infection were reported, and the overall IR was 4.87%. In this study, the neurosurgical procedures or disorders with the top 3 IRs included craniotomy (IR 6.58%), cranioplasty (IR 5.89%), and motor movement disorders (IR 5.43%). Among 13 implanted materials, the implants with the top 3 IRs included polypropylene-polyester, titanium, and polyetheretherketone (PEEK), which were 8.11%, 8.15%, and 7.31%, respectively. Furthermore, the main causative pathogen was Staphylococcus aureus and the countries with the top 3 IRs were Denmark (IR 11.90%), Korea (IR 10.98%), and Mexico (IR 9.26%). Except for the low IR from 1998 to 2007, the overall implant IR after neurosurgical procedures was on the rise.

CONCLUSIONS

In this study, the main pathogen in neurosurgery was S. aureus, which can provide a certain reference for the clinic. In addition, the IRs of polypropylene-polyester, titanium, and PEEK were higher than other materials, which means that more attention should be paid to them. In short, the total IR was high in neurosurgical implants and should be taken seriously.

Cranioplasty following decompressive craniectomy - Analysis of complication rates and neurological outcomes: A single center study

Background

Cranioplasty is the surgical intervention to repair cranial defects in both cosmetic and functional ways. Despite the fact that cranioplasty is a simple procedure, it is still associated with a relatively high complication rate, ranging between series from 12% to 50%.

Methods

The author did a prospective cohort study of patients from August 2015 to December 2017, who had undergone decompressive craniectomy followed by cranioplasty after 6 weeks at our institution. All patients were followed up to 6 months after cranioplasty and complications were recorded both by imaging and clinically. The complications were classified as minor (subgaleal collection, seizures) who did not require the second surgery and major (hydrocephalus, bone flap infection) who required the second surgery. To find out neurological outcome, Glasgow coma score (GCS) and Glasgow outcome scale extended (GOSE) were recorded at 1 month, 3 months, and 6 months.

Results

Overall complication rate in this study was 22.4% (16/72). Subgaleal collection was the most common complication (5.6%), followed by hydrocephalus (4.2%), seizure (4.2%), bone flap infection (2.8%), intracerebral hematoma (2.8%), empyema (1.4%), and subdural hematoma (SDH) (1.4%). Of these, 8.4% (n = 6/72) were major complication (hydrocephalus n = 3, bone flap infection n = 2, and SDH n = 1) which required the second surgery. GCS and GOSE were assessed preoperatively and in postoperative period at 1 month, 3 months, and 6 months. Both mean values of GCS and GOSE showed a significant improvement at 3 and 6 months after cranioplasty.

Conclusion

Cranioplasty after decompressive craniectomy is associated with higher complication rate, but good neurological outcome after surgery always outweighs the complications.

Key Message

Cranioplasty after decompressive craniectomy is associated with higher complication rate, but good neurological outcome after surgery always outweighs the complications. However, complications rate can be brought down by meticulous timing of cranioplasty in a patient of well-controlled comorbidities and precise surgical techniques. However, storing bone in bone bank is not an additional factor for any postcranioplasty complications which was considered previously.

Consensus statement from the International Consensus Meeting on the Role of Decompressive Craniectomy in the Management of Traumatic Brain Injury : Consensus statement

BACKGROUND

Two randomised trials assessing the effectiveness of decompressive craniectomy (DC) following traumatic brain injury (TBI) were published in recent years: DECRA in 2011 and RESCUEicp in 2016. As the results have generated debate amongst clinicians and researchers working in the field of TBI worldwide, it was felt necessary to provide general guidance on the use of DC following TBI and identify areas of ongoing uncertainty via a consensus-based approach.

METHODS

The International Consensus Meeting on the Role of Decompressive Craniectomy in the Management of Traumatic Brain Injury took place in Cambridge, UK, on the 28th and 29th September 2017. The meeting was jointly organised by the World Federation of Neurosurgical Societies (WFNS), AO/Global Neuro and the NIHR Global Health Research Group on Neurotrauma. Discussions and voting were organised around six pre-specified themes: (1) primary DC for mass lesions, (2) secondary DC for intracranial hypertension, (3) peri-operative care, (4) surgical technique, (5) cranial reconstruction and (6) DC in low- and middle-income countries.

RESULTS

The invited participants discussed existing published evidence and proposed consensus statements. Statements required an agreement threshold of more than 70% by blinded voting for approval.

CONCLUSIONS

In this manuscript, we present the final consensus-based recommendations. We have also identified areas of uncertainty, where further research is required, including the role of primary DC, the role of hinge craniotomy and the optimal timing and material for skull reconstruction.

Risk factors for seizures after cranioplasty

PURPOSE

Cranioplasty can improve a patient's psychosocial and cognitive functions after decompressive craniectomy, however seizures are a common complication after cranioplasty. The risk factors for early and late seizures after cranioplasty are unclear. This study is to evaluate the risk factors for early and late seizure after cranioplasty.

METHODS

Two hundred and thirty-eight patients who received cranioplasty following craniectomy between January 2012 and December 2014 were included in this study. The risk factors of the patients with early and late post-cranioplasty seizures were compared to those with no post-cranioplasty seizures.

RESULTS

Seizures (73/238, 30.3%) were the most common complication after cranioplasty. Of these 73 patients, 17 (7.1%) had early post-cranioplasty seizures and 56 (23.5%) had late post-cranioplasty seizures. Early post-cranioplasty seizures were related to a longer interval between craniectomy and cranioplasty (P = 0.006), artificial materials (P < 0.001), and patients with late post-craniectomy seizures (P = 0.001). Late post-cranioplasty seizures were related to the presence of neurological deficits (P = 0.042). After stepwise logistic regression analysis, a longer interval between craniectomy and cranioplasty (P = 0.012; OR: 1.004, 95% CI: 1.001-1.007) and late post-craniectomy seizures (P = 0.033; OR: 4.335, 95% CI: 1.127-16.675) were independently associated with early post-cranioplasty seizures.

CONCLUSION

Delayed cranioplasty procedures and seizures before cranioplasty were significantly associated with early post-cranioplasty seizures. Further studies are warranted to investigate whether early surgery after craniectomy can reduce the risk of early post-cranioplasty seizures.

Cranioplasty following decompressive craniectomy: minor surgical complexity but still high periprocedural complication rates

Cranioplasty following decompressive craniectomy is of low surgical complexity, so much so that it has become the "beginners" cranial case. However, these "simple" procedures may have high complication rates. Identification of specific risk factors would allow targeted intervention to lower the complication rates. The aim of this study was to assess the rate of complications and to evaluate potential risk factors. We conducted a review of all patients who underwent cranioplasty in our center following decompressive craniectomy for stroke or brain trauma between 2009 and 2016. One hundred fifty-two patients were identified. Fifty-three percent were male. Mean age was 48 (range 11-78). Median time from craniectomy until cranioplasty was 102 days (range 14-378). The overall rate of complications, such as postoperative bleeding, seizures, postoperative infection, and hydrocephalus, was 30%. The mortality rate was 1%. None of the following potential risk factors was associated with significantly increased risk of periprocedural complications: gender (p = 0.34), age (p = 0.39), cause of initial surgery (p = 0.08), duration of surgery (p = 0.59), time of surgery (0.24), surgical experience (p = 0.17), and time from craniectomy until cranioplasty (p = 0.27). The 30-day complication rate following cranioplasty is high, but serious permanent deficits from these complications were rare. We found no clear predictor for these 30-day complications, which renders its prevention difficult.

The incidence and treatment of seizures after cranioplasty: a systematic review and meta-analysis

OBJECT

Patients surviving initial decompressive craniectomy are needed to undergo cranioplasty, which is potentially complicated by postoperative seizures. The definite incidence of post-cranioplasty seizures and application of prophylactic antiepileptic drugs remain controversial.

METHODS

We performed systematic review to clarify these issues. Searching through PubMed, Ovid, Web of Science and Cochrane library databases, we included publications recording the incidence of seizures after cranioplasty and prophylactic treatment. We pooled the respective incidence of seizures and 95% confidence interval (CI). The overall effect was expressed with events per 1,000 person-years calculated by the mean follow-up time. Trim and fill method was used to adjust for publication bias. Subgroup analyses were conducted to examine the differences in incidences of seizures.

RESULTS

Two randomized and 14 observational studies were extracted. The pooled incidence of post-cranioplasty seizures was 0.092 (95%CI 0.063, 0.121), which decreased to 0.043 (95%CI 0.010, 0.076) after adjustment. The summarized incidences of early seizures and late seizures were 0.074 (95%CI 0.029, 0.119) and 0.053 (0.027, 0.079) respectively. In the subgroup analyses, randomized studies reported a higher incidence than observational studies, and early cranioplasty (<6 months) resulted in an increased incidence compared with late cranioplasty (>6 months). The overall effect from two randomized studies showed prophylactic antiepileptic drugs reduced nearly 80% of seizures.

CONCLUSION

The estimated incidence of post-cranioplasty seizures is 43 per 1,000 person-years after adjustment. The incidence of early seizures is obviously higher than that of late seizures. Moreover, early cranioplasty leads to more post-cranioplasty seizures than late cranioplasty does. Based on the present evidences, the application of prophylactic antiepileptic drugs effectively reduces seizures.

Predictors of primary autograft cranioplasty survival and resorption after craniectomy

OBJECTIVE

Craniectomy is a common neurosurgical procedure that reduces intracranial pressure, but survival necessitates cranioplasty at a later stage, after recovery from the primary insult. Complications such as infection and resorption of the autologous bone flap are common. The risk factors for complications and subsequent bone flap removal are unclear. The aim of this multicenter, retrospective study was to evaluate the factors affecting the outcome of primary autologous cranioplasty, with special emphasis on bone flap resorption.

METHODS

The authors identified all patients who underwent primary autologous cranioplasty at 3 tertiary-level university hospitals between 2002 and 2015. Patients underwent follow-up until bone flap removal, death, or December 31, 2015.

RESULTS

The cohort comprised 207 patients with a mean follow-up period of 3.7 years (SD 2.7 years). The overall complication rate was 39.6% (82/207), the bone flap removal rate was 19.3% (40/207), and 11 patients (5.3%) died during the follow-up period. Smoking (OR 3.23, 95% CI 1.50-6.95; p = 0.003) and age younger than 45 years (OR 2.29, 95% CI 1.07-4.89; p = 0.032) were found to independently predict subsequent autograft removal, while age younger than 30 years was found to independently predict clinically relevant bone flap resorption (OR 4.59, 95% CI 1.15-18.34; p = 0.03). The interval between craniectomy and cranioplasty was not found to predict either bone flap removal or resorption.

CONCLUSIONS

In this large, multicenter cohort of patients with autologous cranioplasty, smoking and younger age predicted complications leading to bone flap removal. Very young age predicted bone flap resorption. The authors recommend that physicians extensively inform their patients of the pronounced risks of smoking before cranioplasty.

Intracranial Hypotension-associated Cerebral Swelling following Cranioplasty: Report of Two Cases

Cranioplasty is a comparatively simple neurosurgical procedure, and fatal complications are rare. This report describes two cases of critical brain swelling after otherwise uneventful cranioplasty. Both cases had subarachnoid hemorrhage and extremely similar clinical courses. They underwent decompressive craniotomy and clipping in the acute phase and had cranioplasty in the chronic phase, resulting in serious cerebral swelling and death. Deep venous sinus thrombosis was revealed in the autopsy for one case. Although no venous occlusion was identified in the other case, radiological findings suggested venous congestion. In both cases, intraoperative cerebrospinal fluid leakage was massive and was prolonged by a drain; therefore, we hypothesized that intracranial hypotension (IH) caused stagnation of venous flow. Neurosurgeons should be aware that fatal venous congestion induced by IH may occur after cranioplasty. To avoid this, tight dural closure should be obtained, and avoidance of the use of subcutaneous drains should be considered.

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.

Timing of cranioplasty: a 10.75-year single-center analysis of 754 patients

OBJECTIVE Despite their technical simplicity, cranioplasty procedures carry high reported morbidity rates. The authors here present the largest study to date on complications after cranioplasty, focusing specifically on the relationship between complications and timing of the operation. METHODS The authors retrospectively reviewed all cranioplasty cases performed at Harborview Medical Center over the past 10.75 years. In addition to relevant clinical and demographic characteristics, patient morbidity and mortality data were abstracted from the electronic medical record. Cox proportional-hazards models were used to analyze variables potentially associated with the risk of infection, hydrocephalus, seizure, hematoma, and bone flap resorption. RESULTS Over the course of 10.75 years, 754 cranioplasties were performed at a single institution. Sixty percent of the patients who underwent these cranioplasties were male, and the median follow-up overall was 233 days. The 30-day mortality rate was 0.26% (2 cases, both due to postoperative epidural hematoma). Overall, 24.6% percent of the patients experienced at least 1 complication including infection necessitating explantation of the flap (6.6%), postoperative hydrocephalus requiring a shunt (9.0%), resorption of the flap requiring synthetic cranioplasty (6.3%), seizure (4.1%), postoperative hematoma requiring evacuation (2.3%), and other (1.6%). The rate of infection was significantly higher if the cranioplasty had been performed < 14 days after the initial craniectomy (p = 0.007, Holm-Bonferroni-adjusted p = 0.028). Hydrocephalus was significantly correlated with time to cranioplasty (OR 0.92 per 10-day increase, p < 0.001) and was most common in patients whose cranioplasty had been performed < 90 days after initial craniectomy. New-onset seizure, however, only occurred in patients who had undergone their cranioplasty > 90 days after initial craniectomy. Bone flap resorption was the least likely complication for patients whose cranioplasty had been performed between 15 and 30 days after initial craniectomy. Resorption was also correlated with patient age, with a hazard ratio of 0.67 per increase of 10 years of age (p = 0.001). CONCLUSIONS Cranioplasty performed between 15 and 30 days after initial craniectomy may minimize infection, seizure, and bone flap resorption, whereas waiting > 90 days may minimize hydrocephalus but may increase the risk of seizure.