Fatal postoperative tension pneumocephalus after acute subdural hematoma evacuation: a case report.

PURPOSE: Tension pneumocephalus (TP) represents a rare pathology characterized by constant accumulation of air in the intracranial space, being associated with increased risk of herniation, neurologic deterioration and death. Regarding neurosurgical trauma cases, TP is majorly encountered after chronic subdural hematoma evacuation. In this case report, we present a rare case of fatal postoperative TP encountered after craniotomy for evacuation of acute subdural hematoma (aSDH). CASE PRESENTATION: An 83-year old gentleman was presented to the emergency department of our hospital with impaired level of consciousness. Initial examination revealed Glascow Coma Scale (GCS) 3/15, with pupils of 3 mm bilaterally and impaired pupillary light reflex. CT scan demonstrated a large left aSDH, with significant pressure phenomena and midline shift. Patient was subjected to an uneventful evacuation of hematoma via craniotomy and a closed subgaleal drain to gravity was placed. The following day and immediately after his transfer to the CT scanner, he presented with rapid neurologic deterioration with acute onset anisocoria and finally mydriasis with fixed and dilated pupils. Postoperative CT scan showed massive TP, and the patient was transferred to the operating room for urgent left decompressive craniectomy, with no intraoperative signs of entrapped air intracranially. Finally, he remained in severe clinical status, passing away on the eighth postoperative day. CONCLUSION: TP represents a rare but severe neurosurgical emergency that may be also encountered after craniotomy in the acute trauma setting. Involved practitioners should be aware of this potentially fatal complication, so that early detection and proper management are conducted.

Pitching for the hitch: Neodural tenting sutures to prevent post-cranioplasty collection in a sunken craniectomy site.

Post-operative epidural collection is a commonly encountered complication following cranioplasty (CP) in a patient with a sunken skin flap. While on most occasions, the collection is small and resolves spontaneously, on occasion, it may be large enough to warrant evacuation. Further, such collections may predispose to infection and bone flap resorption. Dural hitch sutures were once used routinely in all craniotomies by tacking up the dura at the margins of the craniotomy to the surrounding pericranium to prevent post-operative epidural collection but now several surgeons use them only when deemed absolutely necessary. We describe a variation (in cases where CP is performed in patients with a sunken flap) where several sutures are passed from the neodura through the center of the bone flap (as opposed to the peripherally placed conventional hitch sutures) to obviate the dead space and prevent any post-operative collection.

Anti-coagulants-induced intracranial hemorrhage managed with decompressive craniectomy: a case report of lesson learned.

Introduction and importance: Intracerebral haemorrhage (ICH) secondary to use of anti-coagulants is one of the fearsome complications. Haemorrhage within the intracranial space due to such anti-coagulants results in expansion of the intracranial bleeding despite the reversal of anti-coagulants. Hence, timely surgical intervention can be lifesaving. Case summary: An elderly female who was undergoing management for her deranged coagulation parameters was found to be in a state of features suggestive of stroke. The patient was on regular anti-coagulants medication for her cardiology issues. Computed tomography (CT) scan showed intracranial haemorrhage, which underwent expansion on same day; hence decompressive craniectomy was done. During further stay in the ICU patient's Glasgow coma scale fluctuated but symptomatic improvement was noted. Anti-coagulants adjustment was made by a cardiologist and further, there was no expansion of intracranial bleeding within normal coagulation parameters. Discussion: Anti-coagulants are rampantly used in several cases. Despite the several complications, there is a desperate need for such medications for the betterment of the patient's condition. Pharmacological management is a major modality in the reversal of oral anti-coagulants (OAC)-induced ICH, but in rare cases in the background of OACs-induced ICH, there occurs expansion of haemorrhage. Hence there is a need for neurosurgical intervention, whether it be minimally invasive surgery or decompressive craniectomy. Conclusion: In the background of the low prevalence of OACs-induced ICH, there is an absence of a robust guiding treatment protocol. Furthermore, there exist minimal reported cases which underwent surgical intervention and resulted in a good prognosis.

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.

Bone graft absorption complication following cranioplasty: A retrospective institutional study.

The aim of the present retrospective study was to confer the factors that are related to bone graft absorption and affect the outcomes of patients following cranioplasty (CPL). The present retrospective study includes cases of patients that underwent CPL between February, 2013 and December, 2022. All participants had a follow-up period of 1 to 10 years from the day of discharge from the hospital. In total, 116 (62.3%) of the 186 patients that underwent decompressive craniectomy (DC) were enrolled in the present study for CPL. A total of 109 (93.9%) patients were included in group A, and 7 (6.0%) patients were included in group B. On the whole, the results of the present study suggest that a CPL after 2.5-7.7 months of DC increases the possibility of bone absorption.

Paradoxical herniation associated with hyperbaric oxygen therapy after decompressive craniectomy: A case report.

BACKGROUND: Whether hyperbaric oxygen therapy (HBOT) can cause paradoxical herniation is still unclear. CASE SUMMARY: A 65-year-old patient who was comatose due to brain trauma underwent decompressive craniotomy and gradually regained consciousness after surgery. HBOT was administered 22 d after surgery due to speech impairment. Paradoxical herniation appeared on the second day after treatment, and the patient's condition worsened after receiving mannitol treatment at the rehabilitation hospital. After timely skull repair, the paradoxical herniation was resolved, and the patient regained consciousness and had a good recovery as observed at the follow-up visit. CONCLUSION: Paradoxical herniation is rare and may be caused by HBOT. However, the underlying mechanism is unknown, and the understanding of this phenomenon is insufficient. The use of mannitol may worsen this condition. Timely skull repair can treat paradoxical herniation and prevent serious complications.

Establishment of a model to predict mortality after decompression craniotomy for traumatic brain injury.

BACKGROUND: The mortality rate of patients with traumatic brain injury (TBI) is still high even while undergoing decompressive craniectomy (DC), and the expensive treatment costs bring huge economic burden to the families of patients. OBJECTIVE: The aim of this study was to identify preoperative indicators that influence patient outcomes and to develop a risk model for predicting patient mortality by a retrospective analysis of TBI patients undergoing DC. METHODS: A total of 288 TBI patients treated with DC, admitted to the First Affiliated Hospital of Shantou University Medical School from August 2015 to April 2021, were used for univariate and multivariate logistic regression analysis to determine the risk factors for death after DC in TBI patients. We also built a risk model for the identified risk factors and conducted internal verification and model evaluation. RESULTS: Univariate and multivariate logistic regression analysis identified four risk factors: Glasgow Coma Scale, age, activated partial thrombin time, and mean CT value of the superior sagittal sinus. These risk factors can be obtained before DC. In addition, we also developed a 3-month mortality risk model and conducted a bootstrap 1000 resampling internal validation, with C-indices of 0.852 and 0.845, respectively. CONCLUSIONS: We developed a risk model that has clinical significance for the early identification of patients who will still die after DC. Interestingly, we also identified a new early risk factor for TBI patients after DC, that is, preoperative mean CT value of the superior sagittal sinus (p < .05).

Comparing surgical outcomes: Craniotomy versus decompressive craniectomy in acute subdural hematoma - A systematic review and meta-analysis.

Introduction: Acute subdural hematomas (SDH) pose a significant health risk, often resulting from traumatic head injuries. The choice between surgical interventions, craniotomy, and decompressive craniectomy, remains a subject of debate. This meta-analysis aims to compare outcomes and guide clinical decision-making. Methods: Following PRISMA guidelines, a comprehensive literature search was conducted in databases such as Ovid Medline, PubMed, and Cochrane, up to December 2023. Selection criteria included studies comparing craniotomy and decompressive craniectomy for acute SDH. Data extraction utilized the Newcastle-Ottawa Quality Assessment Tool, and statistical analysis employed the random-effects model. Results: The meta-analysis included 17 studies and 6848 patients. Craniotomy demonstrated a significant reduction in mortality rates (RR 0.80, 95% CI 0.73-0.89, P < 0.0001). GCS scores favored craniotomy for severe cases. GOS outcomes showed a trend favoring craniotomy, particularly in good recovery (RR 1.34, 95% CI 1.04-1.74, P = 0.03). Additional factors explored included co-existing sub-epidural hematoma, mydriasis, extracranial injuries, residual SDH, revision rates, and intracranial pressure. Conclusion: The meta-analysis suggests that craniotomy may be a favorable surgical strategy for acute SDH, displaying a significant decrease in mortality rates and a lower risk of raised intracranial pressure. However, the nuanced nature of outcomes emphasizes the need for a tailored approach, considering broader clinical contexts. Future research should address limitations and provide a basis for well-informed clinical decision-making.

Long-term results of minimally invasive strip craniectomy without helmet therapy for scaphocephaly - a single-centre experience.

Scaphocephaly is the most common type of craniosynostosis and various surgical techniques are used for treatment. Due to late postoperative changes of the head shape, long-term outcome data is important for evaluating any new surgical technique. At our institution, minimally invasive strip craniectomy without regular helmet therapy is the standard treatment in scaphocephalic patients. Between October 2021 and February 2023, we retrospectively examined the skull shape of patients who underwent minimally invasive strip craniectomy for scaphocephaly using a 3D surface scan technique. The cephalic index (CI), the need for helmet therapy and additional cosmetic outcome parameters were investigated. We included 70 patients (72.5% male). The mean follow-up time was 46 (10-125) months and the mean CI was 75.7 (66.7-85.2). In 58 patients, the final cosmetic result was rated as "excellent/good" (mean CI: 76.3; 70.4-85.0), in 11 as "intermediate" (mean CI: 73.3; 66.7-77.6), and in one case as "unsatisfactory" (CI 69.3). The presence of a suboccipital protrusion was associated with a "less than good" outcome. The CI correlated significantly with the overall outcome, the presence of frontal bossing, and the interval between scan and surgery (age at scan). Minimally invasive strip craniectomy is an elegant and safe method to correct scaphocephaly. Our data show good cosmetic results in the long term even without regular postoperative helmet therapy.

Correlation Between Volume and Pressure of Intracranial Space With Craniectomy Surface Area and Brain Herniation: A Phantom-Based Study.

There are proponents of decompressive craniectomy (DC) and its various modifications who claim reasonable clinical outcomes for each of them. Clinical outcome in cases of traumatic brain injury, managed conservatively or aided by different surgical techniques, depends on multiple factors, which vary widely among patients and have complex interplay, making it difficult to compare one case with another in absolute terms. This forms the basis of the perceived necessity to have a standard model to study, compare, and strategize in this field. We designed a phantom-based model and present the findings of the study aimed at establishing a correlation of the volume of intracranial space and changes in intracranial pressure (ICP) with surface area of the craniectomy defect created during DC and brain herniation volume. A roughly hemispherical radio-opaque container was scanned on a 128-slice computed tomography scanner. Craniectomies of different sizes and shapes were marked on the walls of the phantom. Two spherical sacs of stretchable materials were subsequently placed inside the phantom, fixed to three-way connectors, filled with water, and connected with transducers. The terminals of the transducer cables were coupled with the display monitor through a signal amplifier and processor module. Parts of the wall of the phantom were removed to let portions of the sac herniate through the defect, simulating a DC. Volume measurements using AW volume share 7® software were done. Resection of a 12.7 × 11.5 cm part of the wall resulted in a 10-cm-diameter defect in the wall. Volume differential of 35 mL created a midline shift of 5 mm to the side with lesser volume. When measuring pressure in two stretchable sacs contained inside the phantom, there always remained a pressure differential ranging from 1 to 2 mm Hg in different recordings, even with sacs on both sides containing an equal volume of fluids. Creating a circular wall defect of 10 cm in diameter with an intracavitary pressure of 35 mm Hg on the ipsilateral sac and 33 mm on the contralateral sac recorded with intact walls, resulted in a true volume expansion of 48.411 cm3. The herniation resulted in a reduction of pressure in both sacs, with the pressure recorded as 25 mm in the ipsilateral sac and 24 mm in the contralateral sac. The findings closely matched those of the other model-based studies. Refinement of the materials used is likely to provide a valid platform to study cranial volume, ICP, craniectomy size, and brain prolapse volume in real time. The model will help in pre-operatively choosing the most appropriate technique between a classical DC, a hinge craniotomy, and an expansive cranioplasty technique in cases of refractory raised ICP.

Decompressive craniectomy for patients with malignant infarction of the middle cerebral artery: a pooled analysis of two randomized controlled trials.

BACKGROUND: Decompressive craniectomy (DC) reduces mortality without increasing the risk of very severe disability among patients with life-threatening massive cerebral infarction. However, its efficacy was demonstrated before the era of endovascular thrombectomy trials. It remains uncertain whether DC improves the prognosis of patients with malignant middle cerebral artery (MCA) infarction receiving endovascular therapy. METHODS: We pooled data from two trials (DEVT and RESCUE BT studies in China) and patients with malignant MCA infarction were included to assess outcomes and heterogeneity of DC therapy effect. Patients with herniation were dichotomized into DC and conservative groups according to their treatment strategy. The primary outcome was the rate of mortality at 90 days. Secondary outcomes included disability level at 90 days as measured by the modified Rankin Scale score (mRS) and quality-of-life score. The associations of DC with clinical outcomes were performed using multivariable logistic regression. RESULTS: Of 98 patients with herniation, 37 received DC surgery and 61 received conservative treatment. The median (interquartile range) was 70 (62-76) years and 40.8% of the patients were women. The mortality rate at 90 days was 59.5% in the DC group compared with 85.2% in the conservative group (adjusted odds ratio, 0.31 [95% confidence interval (CI), 0.10-0.94]; P=0.04). There were 21.6% of patients in the DC group and 6.6% in the conservative group who had a mRS score of 4 (moderately severe disability); and 10.8% and 4.9%, respectively, had a score of 5 (severe disability). The quality-of-life score was higher in the DC group (0.00 [0.00-0.14] vs 0.00 [0.00-0.00], P=0.004), but DC treatment was not associated with better quality-of-life score in multivariable analyses (adjusted ß Coefficient, 0.02 [95% CI, -0.08-0.11]; p=0.75). CONCLUSIONS: DC was associated with decreased mortality among patients with malignant MCA infarction who received endovascular therapy. The majority of survivors remained moderately severe disability and required improvement on quality of life. CLINICAL TRIAL REGISTRATION: The DEVT trial: http://www.chictr.org. Identifier, ChiCTR-IOR-17013568. The RESCUE BT trial: URL: http://www.chictr.org. Identifier, ChiCTR-INR-17014167.

Emergent Management of Severe Hypothermia, Acidemia, and Coagulopathy in Operative Penetrating Ballistic Cranial Trauma.

Hypothermia in a trauma patient has been associated with increased morbidity and mortality and is more frequently seen in those sustaining traumatic brain injuries (TBIs). Acidosis is an important consequence of hypothermia that leads to derangements across the spectrum of the coagulation cascade. Here, we present a case of a 31-year-old male presented after suffering a right parietal penetrating ballistic injury with an associated subdural hematoma and 7 mm midline shift requiring decompressive craniectomy and external ventricular drain (EVD) placement in the setting of severe hypothermia (28°C) and acidosis (pH 7.12). With aggressive rewarming intraoperatively, the use of full-body forced-air warming, warmed IV fluids, and increasing the ambient room temperature, the patient's acidosis and hypothermia improved to pH 7.20 and 34°C. Despite these aggressive attempts to rewarm the patient, he developed coagulopathy in the setting of concurrent hypothermia and acidosis. This case highlights the importance of prompt reversal of hypothermia due to its potentially fatal effects, particularly in the setting of severe TBIs. We discuss the critical aspects of surgical management of the injury and anesthetic management of hypothermia, acidosis, and coagulopathy perioperatively.

Trends and predictors of decompressive craniectomy in acute ischemic stroke, 2011-2020.

INTRODUCTION: Rates of decompressive craniectomy (DC) in acute ischemic stroke (AIS) have been reported to decline over time, attributed to an increase in endovascular therapy (EVT) preventing the development of malignant cerebral edema. We sought to characterize trends in DC in AIS between 2011 and 2020. MATERIAL AND METHODS: We performed a retrospective observational study of U.S. AIS hospitalizations using the National Inpatient Sample, 2011 to 2020. We calculated rates of DC per 10,000 AIS among all AIS hospitalizations, as well as AIS hospitalizations undergoing invasive mechanical ventilation (IMV). A logistic regression to determine predictors of DC was performed. RESULTS: Of ∼4.4 million AIS hospitalizations, 0.5 % underwent DC; of ∼300,000 AIS with IMV, 5.8 % underwent DC. From 2011 to 2020, the rate of DC increased from 37.4 to 59.1 per 10,000 AIS (p < 0.001). The rate of DC in patients undergoing IMV remained stable at ∼550 per 10,000 (p = 0.088). The most important factors predicting DC were age (OR 4.88, 95 % CI 4.53-5.25), hospital stroke volume (OR 2.61, 95 % CI 2.17-3.14), hospital teaching status (OR 1.54, 95 % CI 1.36-1.75), and transfer status (OR 1.53, 95 % CI 1.41-1.66); EVT status did not predict DC. CONCLUSIONS: The rate of DC in AIS has increased between 2011 and 2020. Our findings are contrary to prior reports of decreasing DC rates over time. Increasing EVT rates do not seem to be preventing the occurrence of DC. Future research should focus on the decision-making process for both clinicians and surrogates regarding DC with consideration of long-term outcomes.

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

INTRODUCTION: Bone flap replacement after a decompressive craniectomy is a low complexity procedure, but with complications that can negatively impact the patient's outcome. A better knowledge of the risk factors for these complications could reduce their incidence. PATIENTS AND METHODS: A retrospective review of a series of 50 patients who underwent bone replacement after decompressive craniectomy at a tertiary center over a 10-year period was performed. Those clinical variables related to complications after replacement were recorded and their risk factors were analyzed. RESULTS: A total of 18 patients (36%) presented complications after bone flap replacement, of which 10 (55.5%) required a new surgery for their treatment. Most of the replacements (95%) were performed in the first 90 days after the craniectomy, with a tendency to present more complications compared to the subsequent period (37.8% vs 20%, p > 0.05). The most frequent complication was subdural hygroma, which appeared later than infection, the second most frequent complication. The need for ventricular drainage or tracheostomy and the mean time on mechanical ventilation, ICU admission, or waiting until bone replacement were greater in patients who presented post-replacement complications. Previous infections outside the nervous system or the surgical wound was the only risk factor for post-bone flap replacement complications (p = 0.031). CONCLUSIONS: Postoperative complications were recorded in more than a third of the patients who underwent cranial bone flap replacement, and at least half of them required a new surgery. A specific protocol aimed at controlling previous infections could reduce the risk of complications and help establish the optimal time for cranial bone flap replacement.

Reoperation-requiring postoperative intracranial haemorrhage after posterior fossa craniotomy: Retrospective case-series.

Introduction: Studies report rates of treatment-requiring postoperative intracranial haemorrhage after craniotomy around 1-2%, but do not distinguish between supratentorial and posterior fossa operations. Reports about intracranial haemorrhages' temporal occurrence show conflicting results. Recommendations for duration of postoperative monitoring vary. Research question: To determine the rate, temporal pattern and clinical presentation of reoperation-requiring postoperative intracranial posterior fossa haemorrhage. Material and methods: This retrospective case-series identified cases operated with posterior fossa craniotomy or craniectomy between January 1, 2007 and December 31, 2021 by an electronic search in the patient administrative database, and collected data about patient- and treatment-characteristics, postoperative monitoring, and the occurrence of haemorrhagic and other serious postoperative complications. Results: We included 62 (n = 34, 55% women) cases with mean age 48 (interquartile range 50) years operated for tumours (n = 34, 55%), Chiari malformations (n = 18, 29%), ischemic stroke (n = 6, 10%) and other lesions (n = 3, 5%). One (2%) 66-year-old woman who was a daily smoker operated with decompressive craniectomy and infarct resection, developed a reoperation-requiring postoperative intracranial haemorrhage after 25.5 h. In four (6%) cases, other serious complications requiring reoperation or transfer from the post anaesthesia care unit or regular bed wards to the intensive care unit occurred after 0.5, 6, 9 and 54 h, respectively. Discussion and conclusion: Treatment-requiring postoperative intracranial haemorrhage and other serious complications after posterior fossa craniotomies occur over a wide timespan and are difficult to capture with a standardized postoperative monitoring time. This indicates that the duration of monitoring should be individualized based on assessment of risk factors.

Innovative Solutions for Patients Who Undergo Craniectomy: Protocol for a Scoping Review.

BACKGROUND: Decompressive craniectomy (DC) is a widely used procedure to alleviate high intracranial pressure. Multidisciplinary teams have designed and implemented external medical prototypes to improve patient life quality and avoid complications following DC in patients awaiting cranioplasty (CP), including 3D printing and plaster prototypes when available. OBJECTIVE: This scoping review aims to understand the extent and type of evidence about innovative external prototypes for patients who undergo DC while awaiting CP. METHODS: This scoping review will use the Joanna Briggs Institute methodology for scoping reviews. This scoping review will include noninvasive medical devices for adult patients who undergo DC while waiting for CP. The search strategy will be implemented in MEDLINE, Embase, Web of Science, Scielo, Scopus, and the World Health Organization (WHO) Global Health Index Medicus. Patent documents were also allocated in Espacenet, Google Patents, and the World Intellectual Property Organization (WIPO) database. RESULTS: This scoping review is not subject to ethical approval as there will be no involvement of patients. The dissemination plan includes publishing the review findings in a peer-reviewed journal and presenting results at conferences that engage the most pertinent stakeholders in innovation and neurosurgery. CONCLUSIONS: This scoping review will serve as a baseline to provide evidence for multidisciplinary teams currently designing these noninvasive innovations to reduce the risk of associated complications after DC, hoping that more cost-effective models can be implemented, especially in low- and middle-income countries. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/50647.

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.

Thickness and design features of clinical cranial implants-what should automated methods strive to replicate?

PURPOSE: New deep learning and statistical shape modelling approaches aim to automate the design process for patient-specific cranial implants, as highlighted by the MICCAI AutoImplant Challenges. To ensure applicability, it is important to determine if the training data used in developing these algorithms represent the geometry of implants designed for clinical use. METHODS: Calavera Surgical Design provided a dataset of 206 post-craniectomy skull geometries and their clinically used implants. The MUG500+ dataset includes 29 post-craniectomy skull geometries and implants designed for automating design. For both implant and skull shapes, the inner and outer cortical surfaces were segmented, and the thickness between them was measured. For the implants, a 'rim' was defined that transitions from the repaired defect to the surrounding skull. For unilateral defect cases, skull implants were mirrored to the contra-lateral side and thickness differences were quantified. RESULTS: The average thickness of the clinically used implants was 6.0 ± 0.5 mm, which approximates the thickness on the contra-lateral side of the skull (relative difference of -0.3 ± 1.4 mm). The average thickness of the MUG500+ implants was 2.9 ± 1.0 mm, significantly thinner than the intact skull thickness (relative difference of 2.9 ± 1.2 mm). Rim transitions in the clinical implants (average width of 8.3 ± 3.4 mm) were used to cap and create a smooth boundary with the skull. CONCLUSIONS: For implant modelers or manufacturers, this shape analysis quantified differences of cranial implants (thickness, rim width, surface area, and volume) to help guide future automated design algorithms. After skull completion, a thicker implant can be more versatile for cases involving muscle hollowing or thin skulls, and wider rims can smooth over the defect margins to provide more stability. For clinicians, the differing measurements and implant designs can help inform the options available for their patient specific treatment.

Surgical strategies in acute subdural hematoma: a meta-analysis of decompressive craniectomy vs. craniotomy.

OBJECTIVE: Acute subdural hematoma (ASDH) stands as a significant contributor to morbidity after severe traumatic brain injuries (TBI). The primary treatment approach for patients experiencing progressive neurological deficits or notable mass effects is the surgical removal of the hematoma, which can be achieved through craniotomy (CO) or decompressive craniectomy (DC). Nevertheless, the choice between these two procedures remains a subject of ongoing debate and controversy. MATERIALS AND METHODS: We conducted a comprehensive literature review, utilizing prominent online databases and manually searching references related to craniotomy and craniectomy for subdural hematoma evacuation up to November 2023. Our analysis focused on outcome variables such as the presence of residual subdural hematoma, the need for revision procedures, and overall clinical outcomes. RESULTS: We included a total of 11 comparative studies in our analysis, encompassing 4269 patients, with 2979 undergoing craniotomy and 1290 undergoing craniectomy, meeting the inclusion criteria. Patients who underwent craniectomy displayed significantly lower scores on the Glasgow Coma Scale (GCS) during their initial presentation. Following surgery, the DC group exhibited a significantly reduced rate of residual subdural (P = 0.009). Additionally, the likelihood of a poor outcome during follow-up was lower in the CO group. Likewise, the mortality rate was lower in the CO group compared to the craniectomy group (OR 0.63, 95% CI 0.41-0.98, I2 = 84%, P = 0.04). CONCLUSION: Our study found that CO was associated with more favorable outcomes in terms of mortality, reoperation rate, and functional outcome while DC was associated with less likelihood of residual subdural hematoma. Upon further investigation of patient characteristics who underwent into either of these interventions, it was very clear that patients in DC cohort have more serious and low pre-op characteristics than the CO group. Nonetheless, brain herniation and advanced age act as independent factor for predicting the outcome irrespective of the intervention.

Poroelastic modelling of brain tissue swelling and decompressive craniectomy treatment in ischaemic stroke.

Brain oedema or tissue swelling that develops after ischaemic stroke can cause detrimental effects, including brain herniation and increased intracranial pressure (ICP). These effects can be reduced by performing a decompressive craniectomy (DC) operation, in which a portion of the skull is removed to allow swollen brain tissue to expand outside the skull. In this study, a poroelastic model is used to investigate the effect of brain ischaemic infarct size and location on the severity of brain tissue swelling. Furthermore, the model will also be used to evaluate the effectiveness of DC surgery as a treatment for brain tissue swelling after ischaemia. The poroelastic model consists of two equations: one describing the elasticity of the brain tissue and the other describing the changes in the interstitial tissue pressure. The model is applied on an idealized brain geometry, and it is found that infarcts with radius larger than approximately 14 mm and located near the lateral ventricle produce worse brain midline shift, measured through lateral ventricle compression. Furthermore, the model is also able to show the positive effect of DC treatment in reducing the brain midline shift by allowing part of the brain tissue to expand through the skull opening. However, the model does not show a decrease in the interstitial pressure during DC treatment. Further improvement and validation could enhance the capability of the proposed poroelastic model in predicting the occurrence of brain tissue swelling and DC treatment post ischaemia.