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

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.

Decompressive craniectomy to cranioplasty: a retrospective observational study using Hospital Episode Statistics in England

Objectives

To investigate the longitudinal trends of decompressive craniectomy (DC) following traumatic brain injury (TBI) or stroke and explore whether the timing of cranial reconstruction affected revision or removal rates using Hospital Episode Statistics (HES) between 2014 and 2019.

Design

Retrospective observational cohort study using HES. The time frame definitions mirror those often used in clinical practice.

Setting

HES data from neurosurgical centres in England.

Participants

HES data related to decompressive craniectomy procedures and cranioplasty following TBI or stroke between 2014 and 2019.

Main outcome measures

The primary outcome was the timing and rate of revision/removal compared with cranioplasty within <12 weeks to ≥12 weeks.

Results

There were 4627 DC procedures, of which 1847 (40%) were due to head injury, 1116 (24%) were due to stroke, 728 (16%) were due to other cerebrovascular diagnoses, 317 (7%) had mixed diagnosis and 619 (13%) had no pre-specified diagnoses. The number of DC procedures performed per year ranged from 876 in 2014-2015 to 967 in 2018-2019. There were 4466 cranioplasty procedures, with 309 (7%) revisions and/or removals during the first postoperative year. There was a 33% increase in the overall number of cranioplasty procedures performed within 12 weeks, and there were 1823 patients who underwent both craniectomy and cranioplasty during the study period, with 1436 (79%) having a cranioplasty within 1 year. However, relating to the timing of cranial reconstruction, there was no evidence of any difference in the rate of revision or removal surgery in the early timing group (6.5%) compared with standard care (7.9%) (adjusted HR 0.93, 95% CIs 0.61 to 1.43; p=0.75).

Conclusions

Overall number of craniectomies and the subsequent requirements for cranioplasty increased steadily during the study period. However, relating to the timing of cranial reconstruction, there was no evidence of an overall difference in the rate of revision or removal surgery in the early timing group.

Variations in the Neurosurgical Management of Depressed Skull Fractures in Adults: An International Cross-Sectional Survey

BACKGROUND

 Depressed skull fractures have been well described since antiquity, yet its management remains controversial. Contentious issues include the use of prophylactic antibiotics and antiepileptics, the role of nonoperative management, and the replacement/removal of bone fragments. Our objective was to explore the management patterns of closed and open depressed skull fractures across the world.

METHODS

 A 23-item, web-based survey was distributed electronically to the members of national neurosurgical associations, and on social media platforms. The survey was open for data collection from December 2020 to April 2021.

RESULTS

 A total of 218 respondents completed the survey, representing 56 countries.With regard to open fractures, most respondents (85.8%) treated less than 50 cases annually. Most respondents (79.4%) offered prophylactic antibiotics to all patients with open fractures, with significant geographical variation (p < 0.001). Less than half of the respondents (48.2%) offered prophylactic antiepileptics. Almost all respondents (>90%) reported the following indications as important for surgical management: (1) grossly contaminated wound, (2) dural penetration, (3) depth of depression, and (4) underlying contusion/hematoma with mass effect. Most respondents treated less than 50 cases of closed depressed skull fractures annually. Most European respondents (81.7%) did not offer prophylactic antiepileptics in comparison to most Asian respondents (52.7%; p < 0.001). Depth of depression, an underlying hematoma/contusion with mass effect, and dural penetration were the most important surgical indications.

CONCLUSIONS

 There remains a great degree of uncertainty in the management strategies employed across the world in treating depressed fractures, and future work should involve multinational randomized trials.

Functional outcome after late cranioplasty after decompressive craniectomy: a single-center retrospective study

OBJECTIVE

The best time for cranioplasty (CP) after decompressive craniectomy (DC) is controversial, and there are no authoritative guidelines yet. Both complications as well as outcome may depend on the timing of CP. The aim of this single-center study was to evaluate the impact of late CP on procedural safety as well as on patient outcome.

METHODS

All patients receiving CP at a tertiary university medical center between 01/2015 and 12/2022 were included retrospectively. Patients' conditions were assessed according to the modified Rankin Scale (mRS) prior to CP and 6 months after. Baseline characteristics, indication for DC, time from DC to CP, and postoperative complications according to the Landriel Ibañez Classification were analyzed.

RESULTS

CP was performed in 271 patients who previously underwent DC due to traumatic brain injury (25.5%), ischemic stroke (29.5%), aneurysmal subarachnoid hemorrhage (26.9%), or intracerebral hemorrhage (18.1%). The median interval between DC and CP was 143 days (interquartile range 112-184 days). Receiver operating characteristic analysis revealed a cut-off of 149 days, where CP performed within 149 days after DC led to an improvement on mRS after CP (p = 0.001). In multivariate analysis, additional rehabilitation after and better mRS before CP were independently associated with improvement of outcome. The rate of complications was similar between early and late CP (24.8% and 25.4%, respectively, p = 0.562).

CONCLUSIONS

Late cranioplasty is a safe procedure. The outcome was improved when additional rehabilitation was performed after cranioplasty and was not associated with the timing of cranioplasty.

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.

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..

Rates of operative intervention for infection after synthetic or autologous cranioplasty: a National Readmissions Database analysis

OBJECTIVE

The aim of this study was to characterize the clinical utilization and associated charges of autologous bone flap (ABF) versus synthetic flap (SF) cranioplasty and to characterize the postoperative infection risk of SF versus ABF using the National Readmissions Database (NRD).

METHODS

The authors used the publicly available NRD to identify index hospitalizations from October 2015 to December 2018 involving elective ABF or SF cranioplasty after traumatic brain injury (TBI) or stroke. Subsequent readmissions were further characterized if patients underwent neurosurgical intervention for treatment of infection or suspected infection. Survey Cox proportional hazards models were used to assess risk of readmission.

RESULTS

An estimated 2295 SF and 2072 ABF cranioplasties were performed from October 2015 to December 2018 in the United States. While the total number of cranioplasty operations decreased during the study period, the proportion of cranioplasties utilizing SF increased (p < 0.001), particularly in male patients (p = 0.011) and those with TBI (vs stroke, p = 0.012). The median total hospital charge for SF cranioplasty was $31,200 more costly than ABF cranioplasty (p < 0.001). Of all first-time readmissions, 20% involved surgical treatment for infectious reasons. Overall, 122 SF patients (5.3%) underwent surgical treatment of infection compared with 70 ABF patients (3.4%) on readmission. After accounting for confounders using a multivariable Cox model, female patients (vs male, p = 0.003), those discharged nonroutinely (vs discharge to home or self-care, p < 0.001), and patients who underwent SF cranioplasty (vs ABF, p = 0.011) were more likely to be readmitted for reoperation. Patients undergoing cranioplasty during more recent years (e.g., 2018 vs 2015) were less likely to be readmitted for reoperation because of infection (p = 0.024).

CONCLUSIONS

SFs are increasingly replacing ABFs as the material of choice for cranioplasty, despite their association with increased hospital charges. Female sex, nonroutine discharge, and SF cranioplasty are associated with increased risk for reoperation after cranioplasty.

Improved strategy for post-traumatic hydrocephalus following decompressive craniectomy: Experience of a single center

Background

Patients with head trauma may develop hydrocephalus after decompressive craniectomy. Many studies have referred one-stage cranioplasty (CP) and ventriculoperitoneal shunt (VPS) was applied to treat cranial defect with post-traumatic hydrocephalus (PTH), but the safety and efficiency of the procedure remain controversial.

Methods

This is a retrospective cohort study including 70 patients of PTH following decompressive craniectomy who underwent simultaneous (50) and separated (20) procedures of cranioplasty and VPS from March 2014 to March 2021 at the authors' institution with at least 30 days of follow-up. Patient characteristics, clinical findings, and complications were collected and analyzed.

Results

Fifty patients with PTH underwent improved simultaneous procedures and 20 patients underwent staged surgeries. Among the cases, the overall complication rate was 22.86%. Complications suffered by patients who underwent one-stage procedure of CP and VPS did not differ significantly, compared with patients in the group of staged procedures (22% vs. 25%, p = 0.763). The significant difference was not observed in the two groups, regarding the complications of subdural/epidural fluid collection (4%/6% vs. 0/2%, p = 1.000/1.000), epidural hemorrhage (6% vs. 4%, p = 0.942), dysfunction of shunting system (0 vs. 2%, p = 0.286), postoperative seizure (8% vs. 4%, p = 1.000), and reoperation case (0 vs. 2%, p = 0.286). No case of subdural hemorrhage, incision/intracranial/abdominal infection, shunting system dysfunction, or reoperation was observed in the group of simultaneous procedure. Complications including subdural/epidural fluid collection, subdural hemorrhage, and incision/intracranial infection were not shown in the case series of the staged procedure group.

Conclusion

The improved simultaneous procedure of cranioplasty and VPS is effective and safe to treat cranial defect and post-traumatic hydrocephalus with low risk of complications.

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.

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.

Subgaleal Effusion and Brain Midline Shift After Cranioplasty: A Retrospective Study Between Polyetheretherketone Cranioplasty and Titanium Cranioplasty After Decompressive Craniectomy

Cranioplasty with polyetheretherketone (PEEK) has recently shown better cerebral protection performance, improved brain function, and aesthetic contour compared with titanium mesh. However, whether patients undergoing PEEK cranioplasty tend to develop subgaleal effusions remains elusive. This retrospective study included patients who underwent cranioplasty with PEEK implants or titanium mesh after decompressive craniectomy between July 2017 and July 2020. Patient information, including general information, location, size of the defect, subgaleal depth, and brain midline shift was collected and statistically analyzed. There were 130 cases of cranioplasty, including 35 with PEEK implants and 95 with a titanium mesh. Patients who underwent cranioplasty with a PEEK implant had a higher subgaleal effusion rate than those who underwent cranioplasty with titanium mesh (85.71% vs. 53.68%, P < 0.001), while a midline shift >5 mm was more frequently observed in the PEEK group than in the titanium group (20% vs. 6.3%, P = 0.021). The PEEK material was the only factor associated with subgaleal effusion after cranioplasty (OR 5.589, P = 0.002). Logistic regression analysis further showed that age was a protective factor against midline shift in the PEEK cranioplasty group (OR 0.837, P = 0.029). Patients who underwent cranioplasty with PEEK implants were more likely to develop severe subgaleal effusion and significant brain midline shifts than those with titanium mesh implants.

Exploring the experiences and challenges for patients undergoing cranioplasty: a mixed-methods study protocol

INTRODUCTION

Cranioplasty is a widely practised neurosurgical procedure aimed at reconstructing a skull defect, but its impact on a patient's rehabilitation following a traumatic brain injury (TBI) or stroke could be better understood. In addition, there are many issues that a TBI patient or the patient who had a stroke and their families may have to adapt to. Insight into some of the potential social barriers, including issues related to social engagement and cosmetic considerations, would be beneficial. Currently, little is known about how this procedure impacts a patient's recovery, the patient's perceptions of rehabilitation precranioplasty and postcranioplasty and the broader issues of cosmesis and social reintegration. This study hopes to understand some of these issues and therefore help inform clinicians of some of the difficulties and perceptions that patients and their relatives may have.

METHODS AND ANALYSIS

A mixed-methods study. Data will be collected through focus groups with healthcare professionals (HCPs) and semi-structured interviews with patients and their relatives, field notes, a researcher diary and a patient questionnaire. Different perspectives will be brought together through method triangulation. Patient and relative data will be analysed using interpretive phenomenological analysis, and HCPs data will be analysed thematically using deductive and inductive coding.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Wales REC 7 ethics committee (Rec ref: 19/WA/0315). There is limited literature regarding a patient's perception of the cranioplasty process, the potential impact on rehabilitation and how this may impact their reintegration into the community. The results of this study will be presented at national brain injury conferences and published in peer-reviewed, national and international journals.

Two-center validation of the Oulu resorption score for bone flap resorption after autologous cranioplasty

OBJECTIVE

Autologous bone has been the gold standard of cranioplasty materials for decades. Unique to autologous cranioplasty, bone flap resorption is a poorly understood and unclearly defined complication. Even further, it has been unclear, whether the resorption process eventually stabilizes over time. Thus, the sufficient follow-up period after autologous cranioplasty is unknown. The Oulu Resorption Score (ORS) is a straight-forward classification system for the radiological interpretation of bone flap resorption. The aims of the present study were to evaluate the reliability of the ORS using intra-class correlation coefficient (ICC) and to assess the temporal progression of the resorption process.

METHODS

We identified 108 consecutive autologous cranioplasty patients treated between 2005 and 2018 in two tertiary referral centers. All 365 head CT scans the patients had undergone were evaluated using the ORS in a blinded, independent two-center setting. Intra- and inter-observer reliabilities were calculated. The ORS was applied to study the temporal progression of the resorption process.

RESULTS

The intra-observer reliability of the ORS was excellent (ICC 0.94, 95%CI 0.93-0.95). Inter-observer reliability was good-to-excellent (ICCs 0.87 and 0.89, 95%CIs 0.84-0.89 and 0.87-0.91, respectively). In scatterplot smoothing analyses, the progression of bone flap resorption appeared to stabilize 12-24 months after cranioplasty.

CONCLUSIONS

ORS is the only validated radiological tool for the standardized analysis of bone flap resorption after autologous cranioplasty. Evaluated using the ORS, the resorption process seemed to stabilize during the first two postoperative years after cranioplasty, suggesting that the sufficient follow-up time after autologous cranioplasty is two years.