Craniectomy Size Research Articles

Posttraumatic hydrocephalus as a complication of decompressive craniectomy-same old story, new perspectives.

Decompressive craniectomy (DC) serves as a vital life-saving intervention, demonstrating efficacy in reducing intracranial pressure (ICP). However, its efficacy hinges on meticulous surgical execution, perioperative management, and vigilance toward potential complications. The incidence of complications associated with DC plays a pivotal role in determining its superiority over medical management for patients experiencing intracranial hypertension following traumatic brain injury (TBI). Severe cases often require more intensive therapy, prolonged mechanical ventilation, and vasopressor treatment. Identifying the optimal moment for early extubation and minimizing vasopressor use is crucial to reducing the risk of complications, including PTH. Our study aims to highlight the potential risks associated with prolonged mechanical ventilation and long-term vasopressor administration. The collected data were demographics, the craniectomy size, the distance from the midline of the craniectomy, the presence or absence of hydrocephalus, duration of mechanical ventilation and vasopressor treatment, and outcome at 30 days. Seventy-two patients with a mean age of 44.2 (range 5-83) were included in the study, with a median craniectomy size of 119.3 cm2. In our series, craniectomy areas ranged between 30 and 207.5 cm2 and had a similar decrease in midline shift in all cases. We did not observe any associations between the surface of craniectomy and the complication rate (p = 0.6302). There was no association between craniectomy size and mortality rate or length of hospital stay. The most common complication of decompressive craniectomy in our study group was posttraumatic hydrocephalus, with an incidence of 13.8%. Our results showed that craniectomy size did not independently affect PTH development (p = 0.5125). Still, there was a strong correlation between prolonged time of vasopressor treatment (p = 0.01843), period of mechanical ventilation (p = 0.04928), and the development of PTH. This study suggests that there is no clear correlation between craniectomy size, midline shift reduction, and survival rate. An extended period of vasopressor treatment or mechanical ventilation is linked with the development of posttraumatic hydrocephalus. Further studies on larger series or randomized controlled studies are needed to better define this correlation.

Preliminary Report of Fully Endoscopic Microvascular Decompression.

Microscopic microvascular decompression (MVD) has been considered to be a useful treatment modality for medically refractory hemifacial spasm (HFS) and trigeminal neuralgia (TN). But, the advent of the endoscopic era has presented new possibilities to MVD surgery. While the microscope remains a valuable tool, the endoscope offers several advantages with comparable clinical outcomes. Thus, fully endoscopic MVD (E-MVD) could be a reasonable alternative to microscopic MVD. This paper explores the safety and efficacy of the fully E-MVD technique. A single-center retrospective study was conducted in 25 patients diagnosed with HFS between September 2019 and July 2023. All surgeries were performed by a single neurosurgeon using the fully E-MVD technique without any assistance of a microscope. The study reviewed intraoperative brainstem auditory evoked potentials and disappearance of the lateral spread response. Outcomes were assessed based on the patients' clinical status immediately after surgery and at their last follow-up. Complications, including facial palsy, hearing loss, ataxia, dysphagia, palsy of other cranial nerves, and cerebrospinal fluid (CSF) leakage, were also examined. The most common offending artery was the anterior inferior cerebellar artery (AICA) in 15 cases (60.0%), followed by the posterior inferior cerebellar artery (PICA) in 8 cases (32.0%), vertebral artery (VA) in 1 case (4.0%), tandem lesions involving the AICA and VA in 1 case (4.0%). Ten patients (40.0%) had pre-operative facial palsy on the ipsilateral side, and 8 patients (32.0%) experienced delayed facial palsy on the ipsilateral side, from which they fully recovered by the last follow-up. The median operation time was 105 minutes. All patients were symptom free immediately after surgery and at the last follow-up. One patient experienced a permanent complication, such as high-frequency hearing loss, from which he partially recovered over time. Fully E-MVD demonstrated similar clinical outcomes to microscopic MVD. It offered a similar complication rate, shorter operation time, and a panoramic view with a smaller craniectomy size. Although there is a learning curve associated with fully E-MVD, it presents a viable alternative in the endoscopic era.

INCIDENCE OF POST TRAUMATIC HYDROCEPHALUS IN PATIENTS UNDERGOING DECOMPRESSIVE CRANIECTOMY

Decompressive craniectomy is a surgical procedure often employed in traumatic brain injury cases to alleviate intracranial pressure. Post-traumatic hydrocephalus, though a rare complication, can occur following this procedure, significantly impacting patient outcomes. Objective: This study aimed to investigate the incidence of post-traumatic hydrocephalus in patients undergoing decompressive craniectomy. Methods: A prospective cross-sectional study was conducted at the Emergency and Neurosurgery Department of Shaheed Mohtarma Benazir Bhutto Trauma Centre (SMBBIT) from June 1, 2022, to December 30, 2022. Demographic and clinical data were collected, including age, gender, Glasgow Coma Scale (GCS) at presentation and time of decompressive craniectomy, type of craniectomy, development of postoperative hydrocephalus, and complications. Results: The majority of patients (55%) were aged 10-15, with males comprising 75% of the cohort. Upon emergency presentation, only 4% of patients exhibited hydrocephalus, with most presenting a GCS between 9 and 13 (56%). Post-craniectomy, hydrocephalus developed in 32% of individuals, with the majority (18%) experiencing onset after 14 days. Significant associations were found between hydrocephalus development and craniectomy size (p=0.04) and distance from the midline (p=0.05). Conclusion: Patients undergoing decompressive craniectomy, particularly those with a superior limit too close to the midline, may be at risk of developing hydrocephalus. Therefore, we advocate for broader craniectomies exceeding 25 mm from the midline to potentially reduce the incidence of post-traumatic hydrocephalus and improve patient outcomes.

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.

Craniectomy size and decompression of the temporal base using the altered posterior question-mark incision for decompressive hemicraniectomy

The altered posterior question-mark incision for decompressive hemicraniectomy (DHC) was proposed to reduce the risk of intraoperative injury of the superficial temporal artery (STA) and demonstrated a reduced rate of wound-healing disorders after cranioplasty. However, decompression size during DHC is essential and it remains unclear if the new incision type allows for an equally effective decompression. Therefore, this study evaluated the efficacy of the altered posterior question-mark incision for craniectomy size and decompression of the temporal base and assessed intraoperative complications compared to a modified standard reversed question-mark incision. The authors retrospectively identified 69 patients who underwent DHC from 2019 to 2022. Decompression and preservation of the STA was assessed on postoperative CT scans and CT or MR angiography. Forty-two patients underwent DHC with the standard reversed and 27 patients with the altered posterior question-mark incision. The distance of the margin of the craniectomy to the temporal base was 6.9 mm in the modified standard reversed and 7.2 mm in the altered posterior question-mark group (p = 0.77). There was no difference between the craniectomy sizes of 158.8 mm and 158.2 mm, respectively (p = 0.45), and there was no difference in the rate of accidental opening of the mastoid air cells. In both groups, no transverse/sigmoid sinus was injured. Twenty-four out of 42 patients in the modified standard and 22/27 patients in the altered posterior question-mark group had a postoperative angiography, and the STA was preserved in all cases in both groups. Twelve (29%) and 5 (19%) patients underwent revision due to wound-healing disorders after DHC, respectively (p = 0.34). There was no difference in duration of surgery. Thus, the altered posterior question-mark incision demonstrated technically equivalent and allows for an equally effective craniectomy size and decompression of the temporal base without increasing risks of intraoperative complications. Previously described reduction in wound-healing complications and cranioplasty failures needs to be confirmed in prospective studies to demonstrate the superiority of the altered posterior question-mark incision.

Comparison of Retroauricular and Reverse Question Mark Incisions for Decompressive Hemicraniectomy

The retroauricular (RA) incision has several theoretical benefits compared with the reverse question mark (RQM) incision for decompressive hemicraniectomy (DHC), but limited data comparing the 2 exist. Consecutive patients who underwent DHC between 2016 and 2022 and survived ≥30 days at a single institution were included. The primary outcome was wound complication within 30 days (30dWC) requiring reoperation. Secondary outcomes included 90-day wound complication (90dWC), craniectomy size in anterior-posterior (AP) and superior-inferior dimensions, distance from the inferior craniectomy margin to the middle cranial fossa (MCF), estimated blood loss (EBL), and operative duration. Multivariate analyses were performed for each outcome. A total of 110 patients (RA group: 27, RQM group: 83) were included. The incidence of 30dWC was 1.2% and 0 in the RQM and RA groups, respectively. The incidence of 90dWC was 2.4% and 3.7% in the RQM and RA groups, respectively. There was no difference in mean AP size (RQM: 15 cm, RA: 14.4 cm; P= 0.18), superior-inferior size (RQM: 11.8 cm, RA: 11.9 cm; P= 0.92), and distance from MCF (RQM: 15.4 mm, RA: 18 mm; P= 0.18). Mean EBL (RQM: 418 mL, RA: 314 mL; P= 0.36) and operative duration (RQM: 103 min, RA: 89 min; P= 0.14) were similar. There was no difference in cranioplasty wound complications, EBL, or operative duration. Wound complications are comparable between the RQM and RA incisions. The RA incision does not compromise craniectomy size or temporal bone removal.

Size of Craniectomy Predicts Approach-Related Shear Bleeding in Poor-Grade Subarachnoid Hemorrhage

Decompressive craniectomy is an option to decrease elevated intracranial pressure in poor-grade aneurysmal subarachnoid hemorrhage (SAH) patients. The aim of the present study was to analyze the size of the bone flap according to approach-related complications in patients with poor-grade SAH. We retrospectively analyzed poor-grade SAH patients (WFNS 4 and 5) who underwent aneurysm clipping and craniectomy (DC or ommitance of bone flap reinsertion). Postoperative CT scans were analyzed for approach-related tissue injury at the margin of the craniectomy (shear bleeding). The size of the bone flap was calculated using the De Bonis equation. Between 01/2012 and 01/2020, 67 poor-grade SAH patients underwent clipping and craniectomy at our institution. We found 14 patients with new shear bleeding lesion in postoperative CT scan. In patients with shear bleeding, the size of the bone flap was significantly smaller compared to patients without shear bleeding (102.1 ± 45.2 cm2 vs. 150.8 ± 37.43 cm2, p > 0.0001). However, we found no difference in mortality rates (10/14 vs. 23/53, p = 0.07) or number of implanted VP shunts (2/14 vs. 18/53, p = 0.2). We found no difference regarding modified Rankin Scale (mRS) 6 months postoperatively. In poor-grade aneurysmal SAH, the initial planning of DC-if deemed necessary -and enlargement of the flap size seems to decrease the rate of postoperatively developed shear bleeding lesions.

Prediction of Shunt-Dependent Hydrocephalus after Primary Supratentorial Intracerebral Hemorrhage with a Focus on the Influence of Craniectomies.

ObjectiveHydrocephalus after intracerebral hemorrhage (ICH) is known to be related to poor prognosis and mortality. We analyzed predictors of permanent hydrocephalus in the patients with surgically treated supratentorial ICH. MethodsFrom 2004 to 2019, a total of 414 patients with surgically treated primary supratentorial ICH were included. We retrospectively analyzed age, sex, preexisting hypertension and diabetes, location and volume of ICH, presence and severity of intraventricular hemorrhage (IVH), and type of surgery. ResultsForty patients (9.7%) required shunt surgery. Concomitant IVH was higher in the ‘shunt required’ group (92.5%) than in the ‘shunt not required’ group (67.9%) (p=0.001). IVH severity was worse in the ‘shunt required’ group (13.5 vs. 7.5, p=0.008). Craniectomy (47.5%) was significantly high in the ‘shunt required’ group. According to multivariable analysis, the presence of an IVH was 8.1 times more frequent and craniectomy was 8.6 times more frequent in the ‘shunt required’ group. In the comparison between craniotomy and craniectomy group, the presence of an IVH was related with a 3.9 times higher (p=0.033) possibility and craniectomies rather than craniotomies with a 7-times higher possibility of shunt surgery (p<0.001). Within the craniectomy group, an increase in the craniectomy area by 1 cm2 was correlated with a 3.2% increase in the possibility of shunt surgery (odds ratio, 1.032; 95% confidence interval, 1.005-1.061; p=0.022). ConclusionPresence of IVH, the severity of IVH and decompressive craniectomy were related to the development of shunt dependent hydrocephalus in the patients with ICH. The increasing size of craniectomy was related with increasing rate of shunt requirement.

Dispersed Bone Spicules as a Cause of Postoperative Headache after Retrosigmoid Vestibular Schwannoma Surgery: A Myth?

Objectives Dispersion of bone dust in the posterior fossa during retrosigmoid craniectomy for vestibular schwannoma (VS) resection could be a source of meningeal irritation and lead to development of persistent postoperative headaches (POH). We aim to determine risk factors, including whether the presence of bone spicules that influence POH after retrosigmoid VS resection. Design Present study is a retrospective case series. Setting The study was conducted at a tertiary skull-base referral center. Participants Adult patients undergoing VS resection via a retrosigmoid approach between November 2017 and February 2020 were included for this study. Main Outcome Measures Development of POH lasting ≥ 3 months is the primary outcome of this study. Results Of 64 patients undergoing surgery, 49 had complete data (mean age, 49 years; 53% female). Mean follow-up time was 2.4 years. At latest follow up, 16 (33%) had no headaches, 14 (29%) experienced headaches lasting <3 months, 19 (39%) reported POH lasting ≥3 months. Twenty-seven (55%) patients had posterior fossa bone spicules detectable on postoperative computed tomography (CT). Age, gender, body mass index, length of stay, tumor diameter, size of craniectomy, the presence of bone spicules, or the amount of posterior petrous temporal bone removed from drilling did not differ significantly between patients with POH and those without. On multivariate logistic regression, patients with POH were less likely to have preoperative brainstem compression by the tumor (odds ratio [OR] = 0.21, p = 0.028) and more likely to have higher opioid requirements during hospitalization (OR = 1.023, p = 0.045). Conclusion The presence of bone spicules in the posterior fossa on postoperative CT did not contribute to headaches following retrosigmoid craniectomy approach for VS resection.

The Effect of Size of Decompressive Craniectomy on Outcome in Deep Spontaneous Intracerebral Hemorrhage

AbstractIntroduction Spontaneous intracerebral hemorrhage (SICH) is one of the most devastating forms of stroke with a mortality of 30 to 40%. We aimed to evaluate the effect of craniotomy size and volume of decompression on surgical outcome, complications, mortality, and morbidity in patients with supratentorial capsuloganglionic bleeds who underwent a decompressive craniectomy (DC) at our institute.Materials and Methods It is a retrospective study done between January 2015 and December 2019. All patients with capsuloganglionic bleeds who had DC and hematoma evacuation were included in the study.Results A total of 55 patients underwent DC for SICH at our hospital during the study period. Mean anteroposterior (AP) diameter of the bone flap was 12.42 cm. The volume of decompression did not influence mortality and morbidity in our study but a larger AP diameter was associated with a higher incidence of hydrocephalus. A smaller craniectomy with an AP diameter of &lt; 12 cm caused a lesser reduction in midline shift (MLS). Persistent postoperative MLS had a significant impact on mortality and its reduction was dependent on the size of craniectomy (p =–0.037)Conclusion DC with a recommended AP diameter of 12 to 13 cm achieves optimal results in terms of reduction in MLS. Larger DC volume carries a higher risk of hydrocephalus and requires close follow-up.

Clinical improvement after cranioplasty and its relation to body position and cerebral hemodynamics.

Cranioplasty after decompressive craniectomy (DC) has been found to improve the neurological condition. The underlying mechanisms are still unknown. The aim of this study is to investigate the roles of the postural changes and atmospheric pressure (AP) in the brain hemodynamics and their relationship with clinical improvement. Seventy-eight patients were studied before and 72h after cranioplasty with cervical and transcranial color Doppler ultrasound (TCCS) in the sitting and supine positions. Craniectomy size, shape, and force exerted by the AP (torque) were calculated. Neurological condition was assessed with the National Institutes of Health Stroke Scale (NIHSS) and the Barthel index. Twenty-eight patients improved after cranioplasty. Their time elapsed from the DC was shorter (214 vs 324days), preoperative Barthel was worse (54 vs 77), internal carotid artery (ICA) mean velocity of the defect side was lower while sitting (14.4 vs 20.9cm/s), and torque over the craniectomy was greater (2480.3 vs 1464.3N*cm). Multivariate binary logistic regression showed the consistency of these changes. TCCS findings were no longer present postoperatively. Lower ICA (defect side) velocity in the sitting position correlates significantly with clinical improvement. Greater torque exerted by the AP might explain different susceptibilities to postural changes, corrected by cranioplasty.

Size does matter: The role of decompressive craniectomy extent for outcome after aneurysmal subarachnoid hemorrhage.

In previous studies in patients with traumatic brain injury and ischemic stroke, the size of decompressive craniectomy (DC) was reported to be paramount with regard to patient outcomes. We aimed to identify the impact of DC size on treatment results in individuals with aneurysmal subarachnoid hemorrhage (SAH). The extent of DC in 232 patients with SAH who underwent bifrontal or hemicraniectomy between January 2003 and December 2015 was analyzed using semi-automated surface measurements. The study endpoints were course of intracranial pressure (ICP) treatment after DC, occurrence of cerebral infarcts, in-hospital mortality, and unfavorable outcome at 6months (defined as modified Rankin scale score >3). The associations of DC size with the study endpoints were adjusted for DC timing, patient age, clinical and radiographic severity of SAH, aneurysm location, and treatment modality. The mean DC surface area was 100.9 (±45.8) cm2 . In multivariate analysis, a large DC (>105cm2 ) was independently associated with a lower risk of cerebral infarcts (adjusted odds ratio [aOR]0.30, 95% confidence interval [CI]0.16-0.56), in-hospital mortality (aOR 0.28, 95%CI0.14-0.56) and unfavorable outcome (aOR 0.51, 95% CI0.27-0.98). Moreover, SAH patients with a small DC size (<75cm2 ) were more likely to require prolonged (>3days, aOR 3.60, 95% CI1.37-9.42) and enhanced (aOR2.31, 95% CI1.12-4.74) postoperative ICP treatment. This is the first study showing the impact of DC size on postoperative ICP control and patient outcome in the context of SAH; specifically, a large craniectomy flap (>105cm2 ) might lead to better outcomes in SAH patients requiring decompressive surgery.

Bony Union and Flap Resorption in Cranioplasty with Autologous Subcutaneous Pocket Preserved Bone Flap: Early Report on an Ambidirectional CT Scan-Based Study

Abstract Introduction Absence of sufficient number of prospective randomized controlled studies and comparatively small sample size and short follow-up period of most of the studies, available so far, have left ambiguity and lack of standardization of different aspects of cranioplasty. Materials and Methods This is an early report of a computed tomography scan image-based ambidirectional study on cranioplasties performed with autologous subcutaneous pocket preserved bone flaps. Retrospective arm compared bony union and factors influencing it between cranioplasties and craniotomies. Patients with poor bony union and aseptic resorption were followed up in the prospective arm. Results Retrospective arm of the study, followed up for five years (mean 32.2 months), comprised 42 patients as cases (Group 1) and 29 as controls (Group 2). Twenty-seven individuals (64.3%) in Group 1 had good bony union, as compared with 20 (68.9%) good unions in Group 2 out of the 29 patients. Four patients (9.5%) in Group 1 showed evidence of flap resorption, a finding absent in any patient in Group 2. Age, sex, smoking habits, superficial skin infection, and method of fixation did not appear to have any implication on bony union. Craniotomies done using Gigli saws fared better as compared with those done with pneumatic saw with lesser flap size–craniectomy size discrepancy, though it was not statistically significant. Fifteen patients have been included in the Prospective arm at the time of submission of this article. Conclusion Ours is a study with a small sample size, unable to put its weight on any side, but can surely add some more data to help the Neurosurgeons in choosing the best for their patients.

Radiographic predictors of clinical outcome in traumatic brain injury after decompressive craniectomy.

Primary decompressive craniectomy (DC) is considered for traumatic brain injury (TBI) patients with clinical deterioration, presenting large amounts of high-density lesions on computed tomography (CT). Postoperative CT findings may be suitable for prognostic evaluation. This study evaluated the radiographic predictors of clinical outcome and survival using pre- and postoperative CT scans of such patients. We enrolled 150 patients with moderate to severe TBI who underwent primary DC. They were divided into two groups based on the 6-month postoperative Glasgow Outcome Scale Extended scores (1-4, unfavorable; 5-8, favorable). Radiographic parameters, including hemorrhage type, location, presence of skull fracture, midline shifting, hemispheric diameter, effacement of cisterns, parenchymal hypodensity, and craniectomy size, were reviewed. Stepwise logistic regression analysis was used to identify the prognostic factors of clinical outcome and 6-month mortality. Multivariable logistic regression analysis revealed that age (odds ratio [OR] = 1.09; 95% confidence interval [CI] 1.032-1.151; p = 0.002), postoperative low density (OR = 12.58; 95% CI 1.247-126.829; p = 0.032), and postoperative effacement of the ambient cistern (OR = 14.52; 95% CI 2.234-94.351; p = 0.005) and the crural cistern (OR = 4.90; 95% CI 1.359-17.678; p = 0.015) were associated with unfavorable outcomes. Postoperative effacement of the crural cistern was the strongest predictor of 6-month mortality (OR = 8.93; 95% CI 2.747-29.054; p = 0.000). Hemispheric hypodensity and effacement of the crural and ambient cisterns on postoperative CT after primary DC seems to associate with poor outcome in patients with TBI.

Does the Size of Unilateral Decompressive Craniectomy Impact Clinical Outcomes in Patients with Intracranial Mass Effect after Severe Traumatic Brain Injury?

ObjectiveDecompressive craniectomy (DC) is one of the treatment modalities in severe traumatic brain injury (TBI), however, there was a lack of evidence for optimal craniectomy size. The authors aimed to investigate optimal DC size and analyze clinical outcome according to craniectomy size.MethodsWe retrospectively reviewed the medical data of 87 patients with a space occupying lesion following TBI who underwent unilateral DC. Craniectomy size was measured by anterior-posterior (AP) diameter and surface estimate (SE). Mortality, clinical outcome, and complications were collected and analyzed according to craniectomy size.ResultsNineteen patients (21.8%) died and 35 patients (40.2%) had a favorable outcome at last follow-up (a mean duration, 30.3±39.4 months; range, 0.2–132.6 months). Receiver operating curve analyses identified AP diameter more than 12.5 cm (area under the curve [AUC]=0.740; p=0.002) and SE more than 98.0 cm2 (AUC=0.752; p=0.001) as cut-off values for survival, and AP diameter more than 13.4 cm (AUC=0.650; p=0.018) and SE more than 107.3 cm2 (AUC=0.685; p=0.003) for favorable outcome. Large craniectomy resulted in a significantly lower mortality rate and a higher rate of favorable outcome than small craniectomy (p=0.005 and p=0.014, respectively). However, procedure related bleeding occurred more frequently in the large craniectomy group (p=0.044).ConclusionUnilateral DC size is associated with clinical outcome of patients with a space occupying lesion following severe TBI. Large craniectomy is needed for survival and favorable outcome.

Decompressive craniectomy of post-traumatic brain injury: an in silico modelling approach for intracranial hypertension management

Traumatic brain injury (TBI) causes brain edema that induces increased intracranial pressure and decreased cerebral perfusion. Decompressive craniectomy has been recommended as a surgical procedure for the management of swollen brain and intracranial hypertension. Proper location and size of a decompressive craniectomy, however, remain controversial and no clinical guidelines are available. Mathematical and computational (in silico) models can predict the optimum geometric conditions and provide insights for the brain mechanical response following a decompressive craniectomy. In this work, we present a finite element model of post-traumatic brain injury and decompressive craniectomy that incorporates a biphasic, nonlinear biomechanical model of the brain. A homogenous pressure is applied in the brain to represent the intracranial pressure loading caused by the tissue swelling and the models calculate the deformations and stresses in the brain as well as the herniated volume of the brain tissue that exits the skull following craniectomy. Simulations for different craniectomy geometries (unilateral, bifrontal and bifrontal with midline bar) and sizes are employed to identify optimal clinical conditions of decompressive craniectomy. The reported results for the herniated volume of the brain tissue as a function of the intracranial pressure loading under a specific geometry and size of craniectomy are exceptionally relevant for decompressive craniectomy planning.

Craniectomy size for subdural haematomas and the impact on brain shift and outcomes.

Midline shift in trauma relates to the severity of head injury. Large craniectomies are thought to help resolve brain shift but can be associated with higher rates of morbidity. This study explores the relationship between craniectomy size and subtemporal decompression for acute subdural haematomas with the resolution of brain compression and outcomes. No systematic study correlating these measures has been reported. A retrospective study of all adult cases of acute subdural haematomas that presented to a Major Trauma Centre and underwent a primary decompressive craniectomy between June 2008 and August 2013. Data collection included patient demographics and presentation, imaging findings and outcomes. All imaging metrics were measured by two independent trained assessors. Compression was measured as midline shift, brainstem shift and cisternal effacement. Thirty-six patients with mean age of 36.1 ± 12.5 (range 16-62) were included, with a median follow-up of 23.5months (range 2.2-109.6). The median craniectomy size was 88.7cm2 and the median subtemporal decompression was 15.0mm. There was significant post-operative resolution of shift as measured by midline shift, brainstem shift and cisternal effacement score (all p < .00001). There was no mortality, and the majority of patients made a good recovery with 82.8% having a Modified Rankin Score of 2 or less. There was no association between craniectomy size or subtemporal decompression and any markers of brain shift or outcome (all R2 < 0.05). This study suggests that there is no clear relationship between craniectomy size or extent of subtemporal decompression and resolution of brain shift or outcome. Further studies are needed to assess the relative efficacy of large craniectomies and the role of subtemporal decompression.

Optimal Bone Flap Size for Decompressive Craniectomy for Refractory Increased Intracranial Pressure in Traumatic Brain Injury: Taking the Patient's Head Size into Account

Decompressive craniectomy (DC) is a widely used treatment for refractory high intracranial pressure (ICP). While the Brain Trauma Foundation guidelines favor large DC, there remains a lack of consensus regarding the optimal size of DC in relationship to the patient's head size. The aim of this study is to determine the optimal size of DC to effectively control refractory ICP in traumatic brain injury and to measure that size with a method that takes into consideration the patient's head size. All cases of unilateral DC performed to control refractory increased ICP due to cerebral edema during a 7½-year period were included. Demographic and injury-related data were collected by retrospective chart review. The patients were categorized in 2 groups: 21 patients with a "small flaps" and 9 patients with a "large flap." Two groups had similar preoperative characteristics. The amount of cerebrospinal fluid drained and the doses of hyperosmolar therapy given were not different between the 2 groups. The postoperative ICP was significantly lower for the large craniectomy flap group: 13.3 mm Hg confidence interval 99% [12.7, 13.8] versus 16.9mm Hg confidence interval 99% [16.5, 17.2] (P= 0.01), and this difference was maintained for 96 hours postoperatively. Better ICP control was achieved in patients who underwent a large decompressive craniectomy (ratio >65%) when compared with smaller craniectomy sizes. The proposed method of measuring the craniectomy size, to our knowledge, is the first to take into account the patient's head size and can be easily measured intraoperatively.

Cranioplasty in Infants Less Than 24 Months of Age: A Retrospective Case Review of Pitfalls, Outcomes, and Complications

Management of pediatric skull defects after decompressive craniectomy (DC) poses unique problems, particularly in children younger than 24 months. These problems include complications such as resorption and infection as well as difficulties with plagiocephaly and reconstruction. The goal of this study was to evaluate bone resorption complications after cranioplasty in patients <24 months. A single-center retrospective case study was performed of all patients younger than 24 months who underwent cranioplasty after DC between 2011 and 2018. The following variables were assessed: injury cause, age at craniotomy, time to cranioplasty, craniectomy size, mode of fixation, drain use, shunt use, subdural fluid collection, resorption, need for synthetic graft revision, and plagiocephaly. A total of 10 patients were identified who met inclusion criteria; 3 patients were excluded for insufficient follow-up. Ages ranged from <1 day to 19 months, with a mean of 10.7 months. Overall rate of cranioplasty resorption was 85.7%, 57.1% of which required revision with synthetic graft. There were univariate trends toward more frequent implant resorption with subdural fluid collection (P=0.1071) and without shunt placement (P= 0.1429). These effects persisted through multivariable analysis and even reached statistical significance in the case of subdural collection when controlling for operative and demographic characteristics (P= 0.01138, P= 0.0694). In addition, univariate analysis showed a trend toward more frequent neurologic complications with greater craniotomy-to-cranioplasty intervals (P= 0.1043), which reached significance on multivariable analysis (P= 0.00518). In patients younger than 24 months undergoing cranioplasty subdural collection, a lack of shunt placement and increased time to cranioplasty were associated with increased rates of resorption.

A Clinical Experience with Decompressive Craniectomy.

To investigate the patients who underwent decompressive craniectomy (DC) for trauma or cerebrovascular disease, and to determine the most suitable treatment protocol for those patients. Overall, 32 patients with trauma or cerebrovascular disease underwent DC. Clinical, radiological and surgical data of surviving patients was retrospectively analysed. The occurence of favourable and unfavourable outcomes during the course of their treatment were recorded. We detected ventriculomegaly in nine out of the 32 patients (9/32, 28.1%) after DC. Of these nine, four patients (4/9, 44.4%) underwent shunt surgery. Cranioplasty performed in 29 of the 32 patients caused epidural hygroma in 13 of them (13/29, 44.8%). Of these 13 patients, three underwent surgery because of progressive increase in the size of hygromas. In the remaining patients, the epidural hygromas regressed spontaneously. Glasgow coma score (GCS) before and after DC surgery (p=0.011 and p=0.006, respectively), timing of cranioplasty (p=0.028), midline shift (p=0.048) and craniectomy size (p=0.047) were significantly associated with ventriculomegaly. Lower GCS, delayed cranioplasty, greater midline shift and larger craniectomy size were found to be associated with hydrocephalus after DC. To avoid hydrocephalus, it may be beneficial to perform shunt surgery first followed by cranioplasty in a single surgical procedure. Additionally, epidural hygromas frequently encountered after a cranioplasty that should be considered and followed up carefully.