Cranial Repair in Children: Techniques, Materials, and Peculiar Issues.

Cranial repair in children deserves particular attention since many issues are still controversial. Furthermore, literature data offer a confused picture of outcome of cranioplasty, in terms of results and complication rates, with studies showing inadequate follow-up and including populations that are not homogeneous by age of the patients, etiology, and size of the bone defect.Indeed, age has merged in the last years as a risk factor for resorption of autologous bone flap that is still the most frequent complication in cranial repair after decompressive craniectomy.Age-related factors play a role also when alloplastic materials are used. In fact, the implantation of alloplastic materials is limited by skull growth under 7 years of age and is contraindicated in the first years if life. Thus, the absence of an ideal material for cranioplasty is even more evident in children with a steady risk of complications through the entire life of the patient that is usually much longer than surgical follow-up.As a result, specific techniques should be adopted according to the age of the patient and etiology of the defect, aiming to repair the skull and respect its residual growth.Thus, autologous bone still represents the best option for cranial repair, though limitations exist. As an alternative, biomimetic materials should ideally warrant the possibility to overcome the limits of other inert alloplastic materials by favoring osteointegration or osteoinduction or both.On these grounds, this paper aims to offer a thorough overview of techniques, materials, and peculiar issues of cranial repair in children.

Estimation of prognosis in patients after decompressive craniectomy after malignant hemispheric infarction: multifactorial scoring scale.

BACKGROUND: Patient's age is considered to be one of the most relevant factors in selecting surgical candidates for decompressive hemicraniectomy after malignant hemispheric infarction. However, questions about surgical indication in older patients, patients with consciousness disorder or patients with large infarctions remain unanswered. OBJECTIVE: Our aim was to design a multifactorial scoring scale based on a combination of patient-specific factors in order to optimize the assessment of prognosis in patients after hemicraniectomy malignant strokes. METHODS: In this prospective observational study with a one-year follow-up, we assessed clinical and imaging data of patients who underwent decompressive hemicraniectomy due to malignant brain infarction. Barthel index was used as a single outcome measure to distinguish favorable vs. unfavorable outcomes. Associations between multiple variables and clinical outcome were assessed. Subsequently, a design of a predictive scoring system was proposed. RESULTS: Age of the patient, preoperative level of consciousness, midline shift, and volume of infarction showed a significant association with postoperative Barthel index. According to the identified factors, a multifactorial prognostic scoring system was introduced, aimed to distinguish between favorable and unfavorable outcomes. Using ROC analysis, it has achieved an AUC of 0.74 (95%CI 0.58‒0.89, p=0.01)CONCLUSIONS: Prediction of postoperative outcome should be based on multiple variables. Our scale, based on the clinical and imaging data, can be used during decision-making to estimate potential benefit of decompressive craniectomy in patients after malignant brain infarction (Tab. 5, Fig. 1, Ref. 32). Text in PDF www.elis.sk Keywords: decompressive hemicraniectomy, malignant hemispheric infarction, indication, outcome, prediction.

Cisternostomy is not beneficial to reduce the occurrence of post-traumatic hydrocephalus in Traumatic Brain Injury.

BACKGROUND: The Cisternostomy is a novel surgical concept in the treatment of Traumatic Brain Injury (TBI), which can effectively drain the bloody cerebrospinal fluid from the skull base cistern, reduce the intracranial pressure, and improve the return of bone flap, but its preventive role in post-traumatic hydrocephalus (PTH) is unknow. The purpose of this paper is to investigate whether Cisternostomy prevents the occurrence of PTH in patients with moderate and severe TBI. METHODS: A retrospective analysis of clinical data of 86 patients with moderate and severe TBI from May 2019 to October 2021 was carried out in the Brain Trauma Center of Tianjin Huanhu Hospital. Univariate analysis was performed to examine the gender, age, preoperative Glasgow Coma Scale (GCS) score, preoperative Rotterdam CT score, decompressive craniectomy rate, intracranial infection rate, the incidence of subdural fluid, and incidence of hydrocephalus in patients between the Cisternostomy group and the non-Cisternostomy surgery group. we also analyzed the clinical outcome indicators like GCS at discharge,6 month GOS-E and GOS-E ≥ 5 in two groups.Additionaly, the preoperative GCS score, decompressive craniectomy rate, age, and gender of patients with PTH and non hydrocephalus were compared. Further multifactorial logistic binary regression was performed to explore the risk factors for PTH. Finally, we conducted ROC curve analysis on the statistically significant results from the univariate regression analysis to predict the ability of each risk factor to cause PTH. RESULTS: The Cisternostomy group had a lower bone flap removal rate(48.39% and 72.73%, p = 0.024)., higer GCS at discharge(11.13 ± 2.42 and 8.93 ± 3.31,p = 0.000) and better 6 month GOS-E(4.55 ± 1.26 and 3.95 ± 1.18, p = 0.029)than the non-Cisternostomy group However, there was no statistical difference in the incidence of hydrocephalus between the two groups (25.81% and 30.91%, p = 0.617). Moreover, between the hydrocephalus group and no hydrocephalus group,there were no significant differences in the incidence of gender, age, intracranial infection, and subdural fluid. While there were statistical differences in peroperative GCS score, Rotterdam CT score, decompressive craniectomy rate, intracranial infection rate, and the incidence of subdural fluid in the two groups, there was no statistical difference in the percentage of cerebral cisterns open drainage between the hydrocephalus group and no hydrocephalus group (32.00% and 37.70%, p = 0.617). Multifactorial logistic binary regression analysis results revealed that the independent risk factors for PTH were intracranial infection (OR = 18.460, 95% CI: 1.864-182.847 p = 0.013) and subdural effusion (OR = 10.557, 95% CI: 2.425-35.275 p = 0.001). Further, The ROC curve analysis showed that peroperative GCS score, Rotterdam CT score and subdural effusion had good ACU(0.785,0.730,and 0.749), with high sensitivity and specificity to predict the occurrence of PTH. CONCLUSIONS: Cisternostomy may decrease morbidities associated with removal of the bone flap and improve the clinical outcome, despite it cannot reduce the disability rate in TBI patients.Intracranial infection and subdural fluid were found to be the independent risk factors for PTH in patients with TBI,and the peroperative GCS score, Rotterdam CT score and subdural effusion had higher sensitivity and specificity to predict the occurrence of PTH. And more importantly, no correlation was observed between open drainage of the cerebral cisterns and the occurrence of PTH, indicating that Cisternostomy may not be beneficial in preventing the occurrence of PTH in patients with moderate and severe TBI.

Customised pre-operative cranioplasty to achieve maximal surgical resection of tumours with osseous involvement-a case series.

PURPOSE: Surgical resection with bony margins would be the treatment of choice for tumours with osseous involvement such as meningiomas and metastasis. By developing and designing pre-operative customised 3D modelled implants, the patient can undergo resection of meningioma and repair of bone defect in the same operation. We present a generalisable method for designing pre-operative cranioplasty in patients to repair the bone defect after the resection of tumours. MATERIALS AND METHODS: We included six patients who presented with a tumour that was associated with overlying bone involvement. They underwent placement of customised cranioplasty in the same setting. A customised implant using a pre-operative imaging was designed with a 2-cm margin to allow for any intra-operative requirements for extending the craniectomy. RESULTS: Six patients were evaluated in this case series. Four patients had meningiomas, 1 patient had metastatic breast cancer on final histology, and 1 patient was found to have an intra-osseous arteriovenous malformation. Craniectomy based on margins provided by a cutting guide was fashioned. After tumour removal and haemostasis, the cranioplasty was then placed. All patients recovered well post-operatively with satisfactory cosmetic results. No wound infection was reported in our series. CONCLUSION: Our series demonstrate the feasibility of utilising pre-designed cranioplasty for meningiomas and other tumours with osseous involvement. Following strict infection protocols, minimal intra-operative handling/modification of the implant, and close follow-up has resulted in good cosmetic outcomes with no implant-related infections.

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

BACKGROUND: Cranioplasty corrects cranial bone defects using various bone substitutes or autologous bone flaps created during a previous craniectomy surgery. These autologous bone flaps can be preserved through subcutaneous preservation (SP) or cryopreservation (CP). AIM: We aim to compare outcomes and complications for both SP and CP techniques to enhance the current evidence about autologous bone flap preservation. METHODS: Five electronic databases were searched to collect all relevant studies. Records were screened for eligibility. Data were extracted from the included studies independently. We categorized surgical site infection (SSI) as either due to Traumatic brain injury (TBI) or not to reveal potential variations in SSI incidence. The double-arm meta-analysis utilized risk ratios (RR) and mean differences (MD) with corresponding confidence intervals (CI) to pool categorical and continuous outcomes, respectively. Proportions with their respective 95% CIs were pooled for single-arm meta-analyses to determine outcomes related to SP technique. RESULTS: Seventeen studies involving 1169 patients were analyzed. No significant difference in SSI rates was observed between SP and CP methods in patients with or without TBI. SP was linked to shorter hospital stays in two studies (194 patients). Single-arm analysis showed a 17% revision surgery rate across five studies (375 patients) and infection rates in 17 studies for SP. New bone formation occurred in 13.2% of patients, with 19.9% showing resorption. CONCLUSION: SP and CP methods showed similar SSI rates post-craniectomy in TBI and non-TBI patients. SP was associated with reduced hospitalization time, low infection rates, and a moderate need for revision surgery.

Letter to editor: Exploring complications following cranioplasty after decompressive hemicraniectomy: A retrospective bicenter assessment of autologous, PMMA and CAD implants.

This study presents a critical analysis of complications following cranioplasty (CP) after decompressive hemicraniectomy, focusing on autologous, polymethylmethacrylate (PMMA), and computer-aided design (CAD) implants. The analysis encompasses a retrospective bicenter assessment, evaluating factors influencing surgical outcomes and emphasizing the significance of material selection in minimizing postoperative complications. The study's comprehensive examination of complication rates associated with various implant materials contributes significantly to understanding CP outcomes. While polymethylmethacrylate (PMMA) and autologous bone flaps (ABFs) exhibited higher rates of surgical site infection (SSI) and explantation, a meta-analysis revealed a contrasting lower infection rate for polyether ether ketone (PEEK) implants. The study underscores the critical role of material selection in mitigating postoperative complications. Despite its strengths, the study's retrospective design, reliance on data from two centers, and limited sample size pose limitations. Future research should prioritize prospective, multicenter studies with standardized protocols to enhance diagnostic accuracy and treatment efficacy in CP procedures.

Chiari Type I Revision Decompressive Surgery Indications and Operative Technique: Experience in a Large Adult Cohort.

BACKGROUND: Chiari malformation is characterized by inferior displacement of the cerebellar tonsils through the foramen magnum, frequently resulting in strain related headaches, and motor/sensory dysfunction. Chiari decompression technique varies significantly, possibly contributing to frequent revisions. We reviewed revision Chiari decompressions at our institution to determine the primary indications for revision and outcomes after revision. METHODS: We retrospectively reviewed patients who underwent revision of Chiari decompression at our institution from 2005 to 2020. Demographics, indications for revision surgery, operative techniques, imaging findings, and preoperative/postoperative symptoms were collected. χ2 test was performed to determine statistical significance using a P < 0.05. Independent predictors of operative outcomes were identified. RESULTS: A total of 46 patients (91% females, mean age 38.8 years) were included for analysis. The median time to revision surgery was 69.1 months (range 0-364 months) with headache (n = 37, 80%) being the most commonly recurring symptom. Large craniectomy (n = 28, 61%) was the most frequent indication for revision surgery. Thirty-two (70%) patients underwent cranioplasty, 20 (43%) required duraplasty, 15 (33%) required arachnoid dissection, and 15 (33%) required tonsillar reduction during revision surgery. Postrevision follow-up (at 8.9 ± 5.2 months average, range 1-18 months), revealed an average reduction in all Chiari-related symptoms relative to symptoms before the revision. CONCLUSIONS: The most common indication for revision Chiari decompression was a large craniectomy resulting in cerebellar ptosis. We found that tonsillar reduction paired with modest craniectomy achieved near-complete resolution of symptoms with minimal complications. For patients with recurrent or persistent sequelae of Chiari malformation after decompression, revision may reduce symptom severity.

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

OBJECTIVE: Describe a new, safe, technique that uses titanium mesh to partially cover skull defects immediately after decompressive craniectomy (DC). METHODS: This study is a retrospective review of 8 patients who underwent DC and placement of a titanium mesh. The mesh partially covered the defect and was placed between the temporalis muscle and the dura graft. The muscle was sutured to the mesh. All patients underwent cranioplasty at a later time. The study recorded and analyzed demographic information, time between surgeries, extra-axial fluid collections, postoperative infections, need for reoperation, cortical hemorrhages, and functional and aesthetic outcomes. RESULTS: After craniectomy, all patients underwent cranioplasty within an average of 112.5 days (30-240 days). One patient reported temporalis muscle atrophy, which was the only complication observed. During the cranioplasties, no adhesions were found between temporalis muscle, titanium mesh, and underlying dura. None of the patients showed complications in the follow-up computerized tomography scans. All patients had favorable aesthetic and functional results. CONCLUSIONS: Placing a titanium mesh as an extra step during DC could have antiadhesive and protective properties, facilitating subsequent cranioplasty by preventing adhesions and providing a clear surgical plane between the temporalis muscle and intracranial tissues. This technique also helps preserve the temporalis muscle and enhances functional and aesthetic outcomes postcranioplasty. Therefore, it represents a safe alternative to other synthetic anti-adhesive materials. Further studies are necessary to draw definitive conclusions and elucidate long-term outcomes, however, the results obtained hold great promise for the safety and efficacy of this technique.

Early detection of aseptic bone necrosis post-cranioplasty: A retrospective CT analysis using Hounsfield units.

This study examined the efficacy of computed tomography (CT)-based Hounsfield units (HU) as early predictors of aseptic bone necrosis, a serious post-cranioplasty complication after autologous cranioplasty. In total, 100 patients who underwent decompressive craniectomy and subsequent autologous cranioplasty were included. The radiodensity of the bone flap was evaluated in HU from CT scans at five follow-up timepoints. HU thresholds were established to predict the development of aseptic bone necrosis. HU demonstrated a declining trend throughout the follow-up period in all patients. Necrosis type I patients showed significant differences at all timepoints from 3 months post-procedure onwards, while necrosis type II patients displayed a significant decline in HU at every follow-up. Optimal thresholds with cut-off A (91.23% of initial HU) and cut-off B (78.73% of initial HU) were established to predict the occurrence of bone necrosis and the need for artificial bone replacement, respectively. Our findings demonstrated the utility of CT-based HU measurements as a simple, non-invasive tool for the early prediction of aseptic bone necrosis following autologous cranioplasty. By delineating specific HU thresholds, our study offers a valuable guide for orchestrating timely follow-ups and advising patients on the necessity of proactive interventions.

Comprehensive functional outcome analysis and importance of bone remodelling on personalized cranioplasty treatment using Poly(methyl methacrylate) bone flaps.

Cranioplasty involves the surgical reconstruction of cranial defects arising as a result of various factors, including decompressive craniectomy, cranial malformations, and brain injury due to road traffic accidents. Most of the modern decompressive craniectomies (DC) warrant a future cranioplasty surgery within 6-36 months. The conventional process of capturing the defect impression and polymethyl methacrylate (PMMA) flap fabrication results in a misfit or misalignment at the site of implantation. Equally, the intra-operative graft preparation is arduous and can result in a longer surgical time, which may compromise the functional and aesthetic outcomes. As part of a multicentric pilot clinical study, we recently conducted a cohort study on ten human subjects during 2019-2022, following the human ethics committee approvals from the participating institutes. In the current study, an important aspect of measuring the extent of bone remodelling during the time gap between decompressive craniectomy and cranioplasty was successfully evaluated. The sterilised PMMA bone flaps were implanted at the defect area during the cranioplasty surgery using titanium mini plates and screws. The mean surgery time was 90 ± 20 min, comparable to the other clinical studies on cranioplasty. No signs of intra-operative and post-operative complications, such as cerebrospinal fluid leakage, hematoma, or local and systemic infection, were clinically recorded. Importantly, aesthetic outcomes were excellent for all the patients, except in a few clinical cases, wherein the PMMA bone flap was to be carefully customized due to the remodelling of the native skull bone. The extent of physiological remodelling was evaluated by superimposing the pre-operative and post-operative CT scan data after converting the defect morphology into a 3D model. This study further establishes the safety and efficacy of a technologically better approach to fabricate patient-specific acrylic bone flaps with improved surgical outcomes. More importantly, the study outcome further demonstrates the strategy to address bone remodelling during the patient-specific implant design.

A comprehensive systematic review and meta-analysis study in comparing decompressive craniectomy versus craniotomy in patients with acute subdural hematoma.

There are two controversial surgery methods which are traditionally used: craniotomy and decompressive craniectomy. The aim of this study was to evaluate the efficacy and complications of DC versus craniotomy for surgical management in patients with acute subdural hemorrhage (SDH) following traumatic brain injury (TBI). We conducted a comprehensive search on PubMed, Scopus, Web of Science, and Embase up to July 30, 2023, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Relevant articles were reviewed, with a focus on studies comparing decompressive craniectomy to craniotomy techniques in patients with SDH following TBI. Ten studies in 2401 patients were reviewed. A total of 1170 patients had a craniotomy, and 1231 had decompressive craniectomy. The mortality rate was not significantly different between the two groups (OR: 0.46 [95% CI: 0.42-0.5] P-value: 0.07). The rate of revision surgery was insignificantly different between the two groups (OR: 0.59 [95% CI: 0.49-0.69] P-value: 0.08). No significant difference was found between craniotomy and decompressive craniectomy regarding unilateral mydriasis (OR: 0.46 [95% CI: 0.35-0.57] P-value < 0.001). However, the craniotomy group had significantly lower rates of non-pupil reactivity (OR: 0.27 [95% CI: 0.17-0.41] P-value < 0.001) and bilateral mydriasis (OR: 0.59 [95% CI: 0.5-0.66] P-value: 0.04). There was also no significant difference in extracranial injury between the two groups, although the odds ratio of significant extracranial injury was lower in the craniotomy group (OR: 0.58 [95% CI: 0.45-0.7] P-value: 0.22). Our findings showed that non-pupil and bilateral-pupil reactivity were significantly more present in decompressive craniectomy. However, there was no significant difference between the two groups regarding mortality rate, extracranial injury, revision surgery, and one-pupil reactivity.

A dynamic nomogram for predicting intraoperative brain bulge during decompressive craniectomy in patients with traumatic brain injury: a retrospective study.

OBJECTIVE: The aim of this paper is to investigate the risk factors associated with intraoperative brain bulge (IOBB), especially the computed tomography (CT) value of the diseased lateral transverse sinus, and to develop a reliable predictive model to alert neurosurgeons to the possibility of IOBB. METHODS: A retrospective analysis was performed on 937 patients undergoing traumatic decompressive craniectomy. A total of 644 patients from Fuzong Clinical Medical College of Fujian Medical University were included in the development cohort, and 293 patients from the First Affiliated Hospital of Shantou University Medical College were included in the external validation cohort. Univariate and multifactorial logistic regression analyses identified independent risk factors associated with IOBB. The logistic regression models consisted of independent risk factors, and receiver operating characteristic curves, calibration, and decision curve analyses were used to assess the performance of the models. Various machine learning models were used to compare with the logistic regression model and analyze the importance of the factors, which were eventually jointly developed into a dynamic nomogram for predicting IOBB and published online in the form of a simple calculator. RESULTS: IOBB occurred in 93/644 (14.4%) patients in the developmental cohort and 47/293 (16.0%) in the validation cohort. Univariate and multifactorial regression analyses showed that age, subdural hematoma, contralateral fracture, brain contusion, and CT value of the diseased lateral transverse sinus were associated with IOBB. A logistic regression model (full model) consisting of the above risk factors had excellent predictive power in both the development cohort [area under the curve (AUC)=0.930] and the validation cohort (AUC=0.913). Among the four machine learning models, the AdaBoost model showed the best predictive value (AUC=0.998). Factors in the AdaBoost model were ranked by importance and combined with the full model to create a dynamic nomogram for clinical application, which was published online as a practical and easy-to-use calculator. CONCLUSIONS: The CT value of the diseased lateral transverse is an independent risk factor and a reliable predictor of IOBB. The online dynamic nomogram formed by combining logistic regression analysis models and machine learning models can more accurately predict the possibility of IOBBs in patients undergoing traumatic decompressive craniectomy.

Prior Thrombectomy Does Not Affect the Surgical Complication Rate of Decompressive Hemicraniectomy in Patients with Malignant Ischemic Stroke.

BACKGROUND: Even though mechanical recanalization techniques have dramatically improved acute stroke care since the pivotal trials of decompressive hemicraniectomy for malignant courses of ischemic stroke, decompressive hemicraniectomy remains a mainstay of malignant stroke treatment. However, it is still unclear whether prior thrombectomy, which in most cases is associated with application of antiplatelets and/or anticoagulants, affects the surgical complication rate of decompressive hemicraniectomy and whether conclusions derived from prior trials of decompressive hemicraniectomy are still valid in times of modern stroke care. METHODS: A total of 103 consecutive patients who received a decompressive hemicraniectomy for malignant middle cerebral artery infarction were evaluated in this retrospective cohort study. Surgical and functional outcomes of patients who had received mechanical recanalization before surgery (thrombectomy group, n = 49) and of patients who had not received mechanical recanalization (medical group, n = 54) were compared. RESULTS: The baseline characteristics of the two groups did significantly differ regarding preoperative systemic thrombolysis (63.3% in the thrombectomy group vs. 18.5% in the medical group, p < 0.001), the rate of hemorrhagic transformation (44.9% vs. 24.1%, p = 0.04) and the preoperative Glasgow Coma Score (median of 7 in the thrombectomy group vs. 12 in the medical group, p = 0.04) were similar to those of prior randomized controlled trials of decompressive hemicraniectomy. There was no significant difference in the rates of surgical complications (10.2% in the thrombectomy group vs. 11.1% in the medical group), revision surgery within the first 30 days after surgery (4.1% vs. 5.6%, respectively), and functional outcome (median modified Rankin Score of 4 at 5 and 14 months in both groups) between the two groups. CONCLUSIONS: A prior mechanical recanalization with possibly associated systemic thrombolysis does not affect the early surgical complication rate and the functional outcome after decompressive hemicraniectomy for malignant ischemic stroke. Patient characteristics have not changed significantly since the introduction of mechanical recanalization; therefore, the results from former large randomized controlled trials are still valid in the modern era of stroke care.

Bone Flap Resorption After Cranioplasty: Risk Factors and Proposal of the Flap Integrity Score.

BACKGROUND: Bone flap resorption is a known complication of postdecompressive autologous cranioplasty. Although several potential etiopathogenetic factors have been investigated, their role is still under discussion. To further complicate things, resorption is not an all-or-nothing event, patients frequently presenting with different degrees of flap remodeling. Focus of this paper was to describe the elaboration of a score quantifying bone resorption according to a set of clinical and radiological criteria, hopefully allowing prompt identification of patients needing resurgery before the development of adverse events. METHODS: In a 10-year period, 281 autologous cranioplasties were performed at our institution following decompressive craniectomy. Pertinent clinical and radiological information was registered. A set of 3 clinical and 3 radiological parameters was established to score the degree of resorption, identified under the acronym FIS (Flap Integrity Score). Three groups of patients emerged, respectively showing no (208), partial (32), and advanced (41) resorption. RESULTS: An overall 14.6% incidence of advanced bone resorption was found in our series. Younger age, bone multifragmentation, higher postcranioplasty Glasgow Outcome Scale scores, <2 cm distance of medial craniectomy border from the midline, and cause leading to decompressive craniectomy were associated to a statistically significant higher risk of developing a relevant bone flap resorption. The first three variables were confirmed as risk factors in multivariate analysis. Flap Integrity Score well discriminated the 3 different groups. CONCLUSIONS: Autologous bone repositioning is still a valuable, low-cost, cosmetically and functionally satisfactory procedure. Nonetheless, although resorption affects a minor percentage of patients, its early identification and treatment can improve long-term results.

Autologous Cranioplasty with Bone Flap Preserved in Conventional Freezers: An Adequate Option in Low Resource Settings.

BACKGROUND: Autologous cranioplasty has been used for decades and is the gold standard treatment in patients who underwent decompressive craniectomy (DC). One of the most common methods to store the cranial bone flap is cryopreservation at very low temperatures (-70 to -80°). The only way to achieve these low temperatures is by using special freezers which are not always available in all medical facilities, especially in low-resource centers. This paper describes our experience with the storage of cranial bone flaps in freezers of conventional refrigerators. METHODS: This retrospective study included patients treated with autologous cranioplasty, operated between 2015 and 2020. The cranial bone flap was stored at -18°C in the freezer of conventional refrigerators. Complications and outcomes were analyzed and compared with reports of patients in whom ultra-low temperature freezers were used for bone flap preservation. RESULTS: Twenty-five patients were included. The average follow-up period was 33 months. Trauma was the most common cause of DC, followed by stroke. The mean age was 36.7. Aseptic bone flap resorption was observed in 4 cases (16%). No cases of infection were observed. CONCLUSIONS: The use of freezers from conventional refrigerators may be an acceptable alternative for the preservation of the cranial bone flap in facilities where special freezers are not available. The rate of aseptic bone necrosis and infections observed in this paper was similar to the incidence of these complications reported in studies where ultra-low temperatures were used.

Frequency and predictors of decompressive craniectomy in ischemic stroke patients treated by mechanical thrombectomy in the ETIS registry.

BACKGROUND AND AIMS: Mechanical thrombectomy (MT) for patients with acute ischemic stroke (AIS) is usually performed in a comprehensive stroke center with on-site neurosurgical expertise. The question of whether MT can be performed in a primary stroke center without a neurosurgical facility is debated. In this context, there is a need to determine the frequency, delay and predictors of neurosurgical procedures in patients treated by MT. This study aims to determine these factors. METHODS: In total, 432 patients under 60years old, diagnosed with an acute ischemic stroke with a large vessel occlusion and treated by MT between January 2018 and December 2019 in six French stroke centers, were selected from the French clinical registry ETIS. Univariate and multivariate logistic regression models were used to identify predictive factors for decompressive craniectomy. RESULTS: Among the 432 included patients, 43 (9.9%) patients with an anterior circulation infarct underwent decompressive craniectomy. Higher admission NIHSS (OR: 1.08 [95% CI: 1.02-1.16]), lower ASPECT (OR per 1 point of decrease 1.53 [1.31-1.79] P<0.001) and preadmission antiplatelet use (OR: 3.03 [1.31-7.01]) were independent risk factors for decompressive craniectomy. The risk of decompressive craniectomy increases to more than 30% with an ASPECT score<4, an NIHSS>16, and current antiplatelet use. CONCLUSION: In this multicenter registry, 9% of acute ischemic stroke patients (<60years old) treated with MT, required decompressive craniectomy. Higher NIHSS score, lower ASPECT score, and preadmission antiplatelet use increase the risk of subsequent requirement for decompressive craniectomy.

Necrosectomy Versus Stand-Alone Suboccipital Decompressive Craniectomy for the Management of Space-Occupying Cerebellar Infarctions-A Retrospective Multicenter Study.

BACKGROUND AND OBJECTIVES: Space-occupying cerebellar stroke (SOCS) when coupled with neurological deterioration represents a neurosurgical emergency. Although current evidence supports surgical intervention in such patients with SOCS and rapid neurological deterioration, the optimal surgical methods/techniques to be applied remain a matter of debate. METHODS: We conducted a retrospective, multicenter study of patients undergoing surgery for SOCS. Patients were stratified according to the type of surgery as (1) suboccipital decompressive craniectomy (SDC) or (2) suboccipital craniotomy with concurrent necrosectomy. The primary end point examined was functional outcome using the modified Rankin Scale (mRS) at discharge and at 3 months (mRS 0-3 defined as favorable and mRS 4-6 as unfavorable outcome). Secondary end points included the analysis of in-house postoperative complications, mortality, and length of hospitalization. RESULTS: Ninety-two patients were included in the final analysis: 49 underwent necrosectomy and 43 underwent SDC. Those with necrosectomy displayed significantly higher rate of favorable outcome at discharge as compared with those who underwent SDC alone: 65.3% vs 27.9%, respectively ( P < .001, odds ratios 4.9, 95% CI 2.0-11.8). This difference was also observed at 3 months: 65.3% vs 41.7% ( P = .030, odds ratios 2.7, 95% CI 1.1-6.7). No significant differences were observed in mortality and/or postoperative complications, such as hemorrhagic transformation, infection, and/or the development of cerebrospinal fluid leaks/fistulas. CONCLUSION: In the setting of SOCS, patients treated with necrosectomy displayed better functional outcomes than those patients who underwent SDC alone. Ultimately, prospective, randomized studies will be needed to confirm this finding.

Role of Decompressive Craniectomy in the Treatment of Malignant Cerebral Venous Sinus Thrombosis: A Single Center Consecutive Case Series Study in China.

OBJECTIVE: Patients with cerebral venous sinus thrombosis (CVST) may die during the acute phase due to increased intracranial pressure and cerebral herniation. The purpose of this study was to assess the role of decompressive craniectomy in the treatment of patients with malignant CVST. METHODS: Patients who underwent decompressive craniectomy and were consequently admitted to the Critical Care Unit, Department of Neurosurgery, at Capital Medical University Xuanwu Hospital from March 2010 to January 2021 were retrospectively examined with follow-up data at 12 months. RESULTS: In total, 14 cases were reviewed, including 9 female and 5 male patients, aged 23-63 years (42.7 ± 12.3 years). Prior to surgery, all patients had a GCS score <9. 6 patients had a unilateral dilated pupil, while 4 patients had bilateral dilated pupils. According to the head computed tomography (CT), all patients had hemorrhagic infarction, and the median midline shift was 9.5 mm before surgery. Thirteen patients underwent unilateral decompressive craniectomy, and 1 patient underwent bilateral decompressive craniectomy, among whom, 9 patients underwent hematoma evacuation. Within 3 weeks of surgery, 3 cases (21.43%) resulted in death, with 2 patients dying from progressive intracranial hypertension and 1 from acute respiratory distress syndrome (ARDS). Eleven patients (78.57%) survived after surgery, of whom 4 (28.57%) patients recovered without disability at 12-month follow-up (mRS 0-1), 2 (14.29%) patients had moderate disability (mRS 2-3), and 5 (35.71%) patients had severe disability (mRS 4-5). CONCLUSIONS: Emergent decompressive craniectomy may provide a chance for survival and enable patients with malignant CVST to achieve an acceptable quality of life (QOL).

Lowering Cranioplasty Infection Incidence with Novel Bone Flap Storage Protocol: A Retrospective Cohort Study.

BACKGROUND: After craniectomy, autologous bone flaps may be stored using wet or dry cryopreservation. After brain edema subsides, they are replaced during an operation termed cranioplasty. Cranioplasty is associated with 15% infection incidence. METHODS: We conducted a retrospective comparison of infection outcomes between wet and dry cryopreservation of cranioplasty bone flaps. Historically, bone flaps were stored utilizing wet cryopreservation-bone flap storage in 1 L of lactated Ringer's solution containing 80 mg gentamicin and 2 g nafcillin in a sterile plastic container secured in an unsterile plastic bag. Our newer dry cryopreservation protocol involved storage in gauze soaked in 80 mg gentamicin and 2 g nafcillin within a 3-layer sterile bag system. RESULTS: A total of 119 autologous bone flaps were included, with median follow-up of 3.9 months from cranioplasty. Overall, 10.9% became infected, requiring subsequent surgery; 18.4% of 49 bone flaps stored using wet cryopreservation became infected compared with only 5.7% of 70 dry cryopreservation bone flaps (P = 0.038; relative risk [RR] 0.311; absolute risk reduction 12.7%). Tobacco use (P = 0.076; RR 3.17) was not associated with increased infection risk. Infection incidence was similar for traumatic craniectomy indications compared to the other indications (12.0% trauma vs. 10.1% other; P = 0.750). On average, infected cranioplasty patients spent 8.5 more days hospitalized and faced increased risk of additional complications. CONCLUSIONS: Dry cryopreservation significantly decreases infection after cranioplasty when compared with wet cryopreservation, and this mitigates additional morbidity, mortality, and costs attributable to cranioplasty infection. Other nonmodifiable risk factors for cranioplasty infection were identified.