The role of decompressive craniectomy in the management of traumatic brain injury: a critical review

Endoscope-Assisted Evacuation of Acute-on-Chronic Subdural Hematomas: A Single-Center Series

Purpose: Acute subdural hematomas are frequent, highly morbid, and affect all age groups. The most common mechanism of injury is a low-velocity fall, and the incidence of the disease is growing due to increasingly aggressive antithrombotic and anticoagulant therapies. In this study, we aimed to share our experience with the endoscopic-assisted evacuation of acute subdural hematoma, a less invasive procedure compared to standard craniotomy.

Methods: We retrospectively reviewed data of all consecutive patients aged 18 years and older who underwent endoscopic-assisted evacuation of acute-on-chronic subdural hematoma at our institution from 2015 to 2019. Preoperative, intraoperative, postoperative, and follow-up data were collected and reported. Statistical tests were done using Python statistical packages.

Results: Of the 35 patients that underwent this procedure, 32 were 18 years and older. The median age was 69.5 years and 37.5% were female. Twenty patients (62.5%) were on antiplatelet therapy, and six patients (18.75%) were on anticoagulants upon presentation. A fall was the most common cause of trauma (71.88%). The median operative time was 107 minutes. The median length of stay in days and Glasgow Coma Scale (GCS) at discharge were 8.5 and 15, respectively. There were no surgical site infections or in-hospital mortality in this series. At the latest follow-up, the median GCS and modified Rankin Scale were 15 and 1, respectively.

Conclusion: Evacuation of acute-on-chronic subdural hematomas can be performed safely and efficiently via a smaller craniotomy and with the assistance of an endoscope. This may represent a less invasive alternative than standard craniotomy/craniectomy in selected patients.

Customized alloplastic cranioplasty of large bone defects by 3D-printed prefabricated mold template after posttraumatic decompressive craniectomy: A technical note

Background

Manufacturing of customized three-dimensional (3D)-printed cranioplastic implant after decompressive craniectomy has been introduced to overcome the difficulties of intraoperative implant molding. The authors present and discuss the technique, which consists of the prefabrication of silicone implant mold using additive manufacturing, also known as 3D printing, and polymethyl methacrylate (PMMA) implant casting.

Methods

To reconstruct a large bone defect sustained after decompressive craniectomy due to traumatic brain injury (TBI), a 3D-printed prefabricated mold template was used to create a customized PMMA implant for cranial vault repair in five consecutive patients.

Results

A superb restoration of the symmetrical contours and curvature of the cranium was achieved in all patients. The outcome was clinically and cosmetically favorable in all of them.

Conclusion

Customized alloplastic cranioplasty using 3D-printed prefabricated mold for casting PMMA implant is easy to perform technique for the restoration of cranial vault after a decompressive craniectomy following moderate-to-severe TBI. It is a valuable and modern technique to advance manufacturing of personalized prefabricated cranioplastic implants used for the reconstruction of large skull defects having complex geometry. It is a safe and cost-effective procedure having an excellent cosmetic outcome, which may considerably decrease expenses and time needed for cranial reconstructive surgery.

Changes in Blood Pressure and Heart Rate during Decompressive Craniectomy

Objective

Rapid increase in intracranial pressure (ICP) can result in hypertension, bradycardia and apnea, referred to as the Cushing phenomenon. During decompressive craniectomy (DC), rapid ICP decreases can cause changes in mean atrial blood pressure (mABP) and heart rate (HR), which may be an indicator of intact autoregulation and vasomotor reflex.

Methods

A total of 82 patients who underwent DC due to traumatic brain injury (42 cases), hypertensive intracerebral hematoma (19 cases), or major infarction (21 cases) were included in this prospective study. Simultaneous ICP, mABP, and HR changes were monitored in one minute intervals during, prior to and 5–10 minutes following the DC.

Results

After DC, the ICP decreased from 38.1±16.3 mmHg to 9.5±14.2 mmHg (p<0.001) and the mABP decreased from 86.4±14.5 mmHg to 72.5±11.4 mmHg (p<0.001). Conversly, overall HR was no significantly changed in HR, which was 100.1±19.7 rate/min prior to DC and 99.7±18.2 rate/min (p=0.848) after DC. Notably when the HR increased after DC, it correlated with a favorable outcome (p<0.001), however mortality was increased (p=0.032) when the HR decreased or remained unchanged.

Conclusion

In this study, ICP was decreased in all patients after DC. Changes in HR were an indicator of preserved autoregulation and vasomotor reflex. The clinical outcome was improved in patients with increased HR after DC.

Decompressive craniectomy: indications and results of 24 cases at the neurosurgery clinic of Fann university hospital of Dakar

Decompressive craniectomy is a surgical technique considered to be the last step in the management of intracranial hypertension. The objective of our study was to evaluate our results in the management of intracranial hypertension by decompressive craniectomy. This was a retrospective study of 24 cases of decompressive craniectomy performed over a 9-year period (from January 2010 to December 2019) at the Fann Neurosurgery Clinic. The mean age of the patients was 33.82 years, there was a male predominance with a sex ratio of 2.42. The most frequent indication was severe cranioencephalic trauma with 50%. The cerebral computed tomography (CT) scan was the key examination and was performed in all our patients. Complications were entirely infectious and were the cause of 73.33% of deaths. Thirty-five percent of the patients had received prior treatment before the decompressive craniectomy. The functional prognosis was good in 44.44% of cases, moderate in 33.33% of cases, 1 (11.11%) patient had a severe disability and 1 (11.11%) patient was in a vegetative state. Mortality rate was 62.5% of patients in our study series. Despite the lack of sophisticated techniques for diagnosis and monitoring of intracranial hypertension, our results remain acceptable with 37.5% survival. The early completion of this surgery allows us to be more efficient with a significant reduction in morbidity and mortality.

Aggressive internal and external decompression as a life-saving surgery in a deeply comatose patient with fixed dilated pupils after severe traumatic brain injury: A case report

Background:

To maximize control of the intracranial pressure in deeply comatose patients with malignant cerebral swelling, combination of the surgical techniques for internal and external brain decompression may be reasonable, as demonstrated in the presented case.

Case Description:

A 55-year-old man was admitted with Glasgow Coma Scale (GCS) score 4, maximally dilated pupils, and absence of the pupillary light and vestibulo-ocular reflexes. Head CT revealed massive acute subdural hematoma, prominent brain shift with subfalcine and transtentorial herniation, and diffuse subarachnoid hemorrhage. Large size decompressive craniectomy and evacuation of subdural hematoma were done, however, prominent swelling of the brain and its protrusion through the bone defect remained. Therefore, extensive temporal lobectomy and removal of the bulk of temporal muscle were additionally attained followed by lax duraplasty. Gradual recovery of the patient was noted from the 1^st postoperative day, and on the 70^th day, his GCS score was 4T4. Three months later, his condition corresponded to the Glasgow Outcome Scale score 3 (severe disability).

Conclusion:

Aggressive internal and external decompression with combination of large size craniectomy, extensive temporal lobectomy, removal of the bulk of temporal muscle, and lax duraplasty should be considered as possible life-saving option in cases of neurosurgical emergencies with malignant cerebral swelling.

Decompressive craniectomy for the treatment of high intracranial pressure in closed traumatic brain injury

BACKGROUND

High intracranial pressure (ICP) is the most frequent cause of death and disability after severe traumatic brain injury (TBI). It is usually treated with general maneuvers (normothermia, sedation, etc.) and a set of first-line therapeutic measures (moderate hypocapnia, mannitol, etc.). When these measures fail, second-line therapies are initiated, which include: barbiturates, hyperventilation, moderate hypothermia, or removal of a variable amount of skull bone (secondary decompressive craniectomy).

OBJECTIVES

To assess the effects of secondary decompressive craniectomy (DC) on outcomes of patients with severe TBI in whom conventional medical therapeutic measures have failed to control raised ICP.

SEARCH METHODS

The most recent search was run on 8 December 2019. We searched the Cochrane Injuries Group's Specialised Register, CENTRAL (Cochrane Library), Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase Classic + Embase (OvidSP) and ISI Web of Science (SCI-EXPANDED & CPCI-S). We also searched trials registries and contacted experts.

SELECTION CRITERIA

We included randomized studies assessing patients over the age of 12 months with severe TBI who either underwent DC to control ICP refractory to conventional medical treatments or received standard care.

DATA COLLECTION AND ANALYSIS

We selected potentially relevant studies from the search results, and obtained study reports. Two review authors independently extracted data from included studies and assessed risk of bias. We used a random-effects model for meta-analysis. We rated the quality of the evidence according to the GRADE approach.

MAIN RESULTS

We included three trials (590 participants). One single-site trial included 27 children; another multicenter trial (three countries) recruited 155 adults, the third trial was conducted in 24 countries, and recruited 408 adolescents and adults. Each study compared DC combined with standard care (this could include induced barbiturate coma or cooling of the brain, or both). All trials measured outcomes up to six months after injury; one also measured outcomes at 12 and 24 months (the latter data remain unpublished). All trials were at a high risk of bias for the criterion of performance bias, as neither participants nor personnel could be blinded to these interventions. The pediatric trial was at a high risk of selection bias and stopped early; another trial was at risk of bias because of atypical inclusion criteria and a change to the primary outcome after it had started. Mortality: pooled results for three studies provided moderate quality evidence that risk of death at six months was slightly reduced with DC (RR 0.66, 95% CI 0.43 to 1.01; 3 studies, 571 participants; I2 = 38%; moderate-quality evidence), and one study also showed a clear reduction in risk of death at 12 months (RR 0.59, 95% CI 0.45 to 0.76; 1 study, 373 participants; high-quality evidence). Neurological outcome: conscious of controversy around the traditional dichotomization of the Glasgow Outcome Scale (GOS) scale, we chose to present results in three ways, in order to contextualize factors relevant to clinical/patient decision-making. First, we present results of death in combination with vegetative status, versus other outcomes. Two studies reported results at six months for 544 participants. One employed a lower ICP threshold than the other studies, and showed an increase in the risk of death/vegetative state for the DC group. The other study used a more conventional ICP threshold, and results favoured the DC group (15.7% absolute risk reduction (ARR) (95% CI 6% to 25%). The number needed to treat for one beneficial outcome (NNTB) (i.e. to avoid death or vegetative status) was seven. The pooled result for DC compared with standard care showed no clear benefit for either group (RR 0.99, 95% CI 0.46 to 2.13; 2 studies, 544 participants; I2 = 86%; low-quality evidence). One study reported data for this outcome at 12 months, when the risk for death or vegetative state was clearly reduced by DC compared with medical treatment (RR 0.68, 95% CI 0.54 to 0.86; 1 study, 373 participants; high-quality evidence). Second, we assessed the risk of an 'unfavorable outcome' evaluated on a non-traditional dichotomized GOS-Extended scale (GOS-E), that is, grouping the category 'upper severe disability' into the 'good outcome' grouping. Data were available for two studies (n = 571). Pooling indicated little difference between DC and standard care regarding the risk of an unfavorable outcome at six months following injury (RR 1.06, 95% CI 0.69 to 1.63; 544 participants); heterogeneity was high, with an I2 value of 82%. One trial reported data at 12 months and indicated a clear benefit of DC (RR 0.81, 95% CI 0.69 to 0.95; 373 participants). Third, we assessed the risk of an 'unfavorable outcome' using the (traditional) dichotomized GOS/GOS-E cutoff into 'favorable' versus 'unfavorable' results. There was little difference between DC and standard care at six months (RR 1.00, 95% CI 0.71 to 1.40; 3 studies, 571 participants; low-quality evidence), and heterogeneity was high (I2 = 78%). At 12 months one trial suggested a similar finding (RR 0.95, 95% CI 0.83 to 1.09; 1 study, 373 participants; high-quality evidence). With regard to ICP reduction, pooled results for two studies provided moderate quality evidence that DC was superior to standard care for reducing ICP within 48 hours (MD -4.66 mmHg, 95% CI -6.86 to -2.45; 2 studies, 182 participants; I2 = 0%). Data from the third study were consistent with these, but could not be pooled. Data on adverse events are difficult to interpret, as mortality and complications are high, and it can be difficult to distinguish between treatment-related adverse events and the natural evolution of the condition. In general, there was low-quality evidence that surgical patients experienced a higher risk of adverse events.

AUTHORS' CONCLUSIONS

Decompressive craniectomy holds promise of reduced mortality, but the effects of long-term neurological outcome remain controversial, and involve an examination of the priorities of participants and their families. Future research should focus on identifying clinical and neuroimaging characteristics to identify those patients who would survive with an acceptable quality of life; the best timing for DC; the most appropriate surgical techniques; and whether some synergistic treatments used with DC might improve patient outcomes.

Classification of bone flap resorption after cranioplasty: a proposal for a computed tomography-based scoring system

Background

Bone flap resorption (BFR) is the most prevalent complication resulting in autologous cranioplasty failure, but no consensus on the definition of BFR or between the radiological signs and relevance of BFR has been established. We set out to develop an easy-to-use scoring system intended to standardize the interpretation of radiological BFR findings.

Methods

All 45 autologous cranioplasty patients operated on at Oulu University Hospital from 2004 to 2014 were identified, and the bone flap status of all the available patients was evaluated using the new scoring system. Derived from previous literature, a three-variable score for the detection of BFR changes is proposed. The variables “Extent” (estimated remaining bone volume), “Severity” (possible perforations and their measured diameter), and “Focus” (the number of BFR foci within the flap) are scored from 0 to 3 individually. Using the sum of these scores, a score of 0–9 is assigned to describe the degree of BFR. Additionally, independent neurosurgeons assessed the presence and relevance of BFR from the same data set. These assessments were compared to the BFR scores in order to find a score limit for relevant BFR.

Results

BFR was considered relevant by the neurosurgeons in 11 (26.8%) cases. The agreement on the relevance of BFR demonstrated substantial strength (κ 0.64, 95%CI 0.36 to 0.91). The minimum resorption score in cases of relevant BFR was 5. Thus, BFR with a resorption score ≥ 5 was defined relevant (grades II and III). With this definition, grade II or III BFR was found in 15 (36.6%) of our patients. No risk factors were found to predict relevant BFR.

Conclusions

The score was proven to be easy to use and we recommend that only cases with grades II and III BFR undergo neurosurgical consultation. However, general applicability can only be claimed after validation in independent cohorts.

Craniotomy or Decompressive Craniectomy for Acute Subdural Hematomas: Surgical Selection and Clinical Outcome

Objective

Craniotomy (CO) and decompressive craniectomy (DC) are two main surgical options for acute subdural hematomas (ASDH). However, optimal selection of surgical modality is unclear and decision may vary with surgeon's experience. To clarify this point, we analyzed preoperative findings and surgical outcome of patients with ASDH treated with CO or DC.

Methods

From January 2010 to December 2014, data for 46 patients with ASDH who underwent CO or DC were retrospectively reviewed. The demographic, clinical, imaging and clinical outcomes were analyzed and statistically compared.

Results

Twenty (43%) patients underwent CO and 26 (57%) patients received DC. In DC group, preoperative Glascow Coma Scale was lower (p=0.034), and more patient had non-reactive pupil (p=0.004). Computed tomography findings of DC group showed more frequent subarachnoid hemorrhage (p=0.003). Six month modified Rankin Scale showed favorable outcome in 60% of CO group and 23% of DC group (p=0.004). DC was done in patient with more unfavorable preoperative features (p=0.017). Patients with few unfavorable preoperative features (<6) had good outcome with CO (p<0.001).

Conclusion

In selective cases of few unfavorable clinical findings, CO may also be an effective surgical option for ASDH. Although DC remains to be standard of surgical modality for patients with poor clinical status, CO can be an alternative considering the possible complications of DC.

Gradual and controlled decompression for brain swelling due to severe head injury

Patients suffering from uncontrollable intracranial hypertension due to posttraumatic brain swelling (BS) generally either die or survive in an extremely disabled state. Decompressive craniectomy (DC) with dural augmentation may be the best method to assist these patients. However, the efficacy of DC on functional outcomes remains controversial. One of the factors contributing to poor outcomes could be intraoperative brain extrusion, which is an acute potential complication of DC. The authors have adopted a new surgical technique for traumatic BS that can prevent and control massive intraoperative BS (IOS). In the past 3 years, the authors have used a unique technique, called "gradual and controlled decompression", in the treatment of posttraumatic BS. This procedure consists of creating numerous small dural openings and removing clots; enlarging fenestration in the frontal and temporal basal regions to detect and treat brain contusion; making U-shaped, discontinuous, small dural incisions around the circumference of the craniotomy; and performing an augmentation duraplasty through the discontinuous small opening with dural prosthetic substances. This technique has been employed in 23 patients suffering from posttraumatic BS. In all cases, IOS was prevented and controlled through gradual stepwise decompression, and expanded duraplasty was performed successfully. This new surgical approach for posttraumatic BS can prevent severe extrusion of the brain through the craniotomy defect and allows the gradual and gentle release of the subdural space. Further clinical studies should be conducted to estimate the impact of this new technique on morbidity and mortality rates.

The impact of time to surgery on outcomes in patients with traumatic brain injury: a literature review

AIM

To review the relationship between the time interval to surgery and outcomes in patients with traumatic brain injury (TBI).

METHODS

A literature review was conducted by employing several search strategies, including electronic database searches and footnote chasing. The quality of the selected studies was assessed in terms of internal and external validity. Data regarding authors, publication year, sample size, surgical procedure, time interval to surgery, and outcome was extracted.

RESULTS

Among 16 finally selected studies, five studies (31.3%) found that patient outcome was significantly affected by the timing of surgery and 11 (68.7%) did not. The impact of time to surgery on outcomes was not significant in most (75%) of the studies targeting patients with severe TBI. The effect of time to surgery on outcome showed different findings depending on the type of surgical procedure. A significant effect of time to surgery on outcome was reported in one (14.2%) of the seven studies targeting patients who underwent haematoma evacuation and in four (44.4%) of the nine studies on patients who underwent decompressive craniectomy.

CONCLUSION

This review shows that current opinion is still divided regarding when to operate. Despite this discrepancy, most authors agree that the timing of decompression is crucial to outcome.

Mitigating spinal cord distraction injuries: the effect of durotomy in decreasing cord interstitial pressure in vitro

STUDY DESIGN

The present study involved an in vitro examination of spinal cord interstitial pressure (CIP) during distraction before and after durotomy in three spinal cord segments obtained from five pigs.

OBJECTIVES

To determine whether durotomy can be used to decrease the elevated CIP associated with spinal cord distraction.

SUMMARY OF BACKGROUND DATA

Spinal cord distraction is a known cause of spinal cord injury. Several articles describing the pathophysiology of cord distraction injuries suggest that the underlying mechanism of injury is a microvascular ischemic event. The authors have previously described an increase in CIP with spinal cord distraction, with average pressures of 23 mmHg at loads of 1,000 g. To date, there are no published studies that have evaluated the efficacy of intentional durotomies as a treatment for elevated CIP.

METHODS

A total of 15 spinal cord sections were harvested from pigs and distracted while immersed in saline, using a fixed 1,000 g distraction force. The CIP decay was then measured at 30-s intervals for 10 min. The distraction/relaxation maneuver was performed six times with continuous CIP monitoring and was subsequently followed by durotomy.

RESULTS

The pressure-decay curves were similar for each specimen, but varied according to individual pigs and anatomical levels. CIP decayed over the first 4 min of distraction and remained constant for the final 6 min. Longitudinal durotomy led to a dramatic drop in CIP toward baseline and appeared to be as effective as transverse durotomy with regard to the normalization of pressure.

CONCLUSION

Spinal cord distraction causes elevations in CIP. Durotomy lowers elevated CIP in vitro and may be effective at lowering CIP in vivo. Further study is required to evaluate the usefulness of durotomy in vivo.

Surgical treatment of elevated intracranial pressure: decompressive craniectomy and intracranial pressure monitoring

Surgical techniques that address elevated intracranial pressure include (1) intraventricular catheter insertion and cerebrospinal fluid drainage, (2) removal of an intracranial space-occupying lesion, and (3) decompressive craniectomy. This review discusses the role of surgery in the management of elevated intracranial pressure, with special focus on intraventricular catheter placement and decompressive craniectomy. The techniques and potential complications of each procedure are described, and the existing evidence regarding the impact of these procedures on patient outcome is reviewed. Surgical management of mass lesions and ischemic or hemorrhagic stroke occurring in the posterior fossa is not discussed herein.

Customized cranioplasty implants using three-dimensional printers and polymethyl-methacrylate casting

Objective

The prefabrication of customized cranioplastic implants has been introduced to overcome the difficulties of intra-operative implant molding. The authors present a new technique, which consists of the prefabrication of implant molds using three-dimensional (3D) printers and polymethyl-methacrylate (PMMA) casting.

Methods

A total of 16 patients with large skull defects (>100 cm²) underwent cranioplasty between November 2009 and April 2011. For unilateral cranial defects, 3D images of the skull were obtained from preoperative axial 1-mm spiral computed tomography (CT) scans. The image of the implant was generated by a digital subtraction mirror-imaging process using the normal side of the cranium as a model. For bilateral cranial defects, precraniectomy routine spiral CT scan data were merged with postcraniectomy 3D CT images following a smoothing process. Prefabrication of the mold was performed by the 3D printer. Intraoperatively, the PMMA implant was created with the prefabricated mold, and fit into the cranial defect.

Results

The median operation time was 184.36±26.07 minutes. Postoperative CT scans showed excellent restoration of the symmetrical contours and curvature of the cranium in all cases. The median follow-up period was 23 months (range, 14-28 months). Postoperative infection was developed in one case (6.2%) who had an open wound defect previously.

Conclusion

Customized cranioplasty PMMA implants using 3D printer may be a useful technique for the reconstruction of various cranial defects.

Operative and nonoperative linguistic outcomes in brain injury patients

OBJECTIVE AND BACKGROUND

Linguistic function is one of vulnerable aspects of traumatic brain injury (TBI) which may have destructive effects on patients' communicative activities and daily life, years following trauma. This paper attempts to answer the controversy whether surgery affects increase and decrease of linguistic impairment or not.

MATERIALS AND METHODS

Two hundred forty-one TBI patients aged 18-65 with abnormal CT findings and at least 20 minute post-trauma amnesia (PTA), who were conscious at discharge, participated in this study. Based on operative intervention, the samples were divided into two groups: operative and nonoperative. Cognitive and aphasic deficits were inspected formally and pragmatic disorder was informally appraised at discharge.

RESULTS

The groups had no significant differences in aphasia incidence and language pragmatic impairment, though they were significantly distinctive in aphasia subcategories and cognitive deficit after trauma. Fluent aphasia was more common in both groups alike. In aphasia subcategories, however, transcortical sensory aphasia (TSA) in operative and anomia in nonoperative group were the most prevalent. Several variables appeared strikingly related to higher aphasia in operative groups as follows: moderate to severe injury, 18-35 and over 50 years of age, more than 1 week PTA, intracranial surgery of multiple lesions in left or bilateral hemisphere fronto-temporal cortex plus post-trauma cognitive and pragmatic impairments, and diffuse axonal injuries.

DISCUSSION

Almost certainly, meaningful drop of cognitive function post surgery roots back in significant loss of initial consciousness level. Related factors to postoperative aphasia suggest taking policies through surgery intervention. Discerning the indispensable contributions of neurosurgeons, neurolinguists, and neuroscientists, results inspire more clinical future studies.

Role of preoperative 3-dimensional computed tomography reconstruction in depressed skull fractures treated with craniectomy: a case report of forensic interest

Patients affected by cranial trauma with depressed skull fractures and increased intracranial pressure generally undergo neurosurgical intervention. Because craniotomy and craniectomy remove skull fragments and generate new fracture lines, they complicate forensic examination and sometimes prevent a clear identification of skull fracture etiology. A 3-dimensional reconstruction based on preoperative computed tomography (CT) scans, giving a picture of the injuries before surgical intervention, can help the forensic examiner in identifying skull fracture origin and the means of production.We report the case of a 41-year-old-man presenting at the emergency department with a depressed skull fracture at the vertex and bilateral subdural hemorrhage. The patient underwent 2 neurosurgical interventions (craniotomy and craniectomy) but died after 40 days of hospitalization in an intensive care unit. At autopsy, the absence of various bone fragments did not allow us to establish if the skull had been stricken by a blunt object or had hit the ground with high kinetic energy. To analyze bone injuries before craniectomy, a 3-dimensional CT reconstruction based on preoperative scans was performed. A comparative analysis between autoptic and radiological data allowed us to differentiate surgical from traumatic injuries. Moreover, based on the shape and size of the depressed skull fracture (measured from the CT reformations), we inferred that the man had been stricken by a cylindric blunt object with a diameter of about 3 cm.

Decompressive craniectomy: technical note

Decompressive craniectomy is a neurosurgical technique in which a portion of the skull is removed to reduce intracranial pressure. The rationale for this procedure is based on the Monro-Kellie Doctrine; expanding the physical space confining edematous brain tissue after traumatic brain injury will reduce intracranial pressure. There is significant debate over the efficacy of decompressive craniectomy despite its sound rationale and historical significance. Considerable variation in the employment of decompressive craniectomy, particularly for secondary brain injury, explains the inconsistent results and mixed opinions of this potentially valuable technique. One way to address these concerns is to establish a consistent methodology for performing decompressive craniectomies. The purpose of this paper is to begin accomplishing this goal and to emphasize the critical points of the hemicraniectomy and bicoronal (Kjellberg type) craniectomy.

Cerebral hemodynamic changes in severe head injury patients undergoing decompressive craniectomy

OBJECTIVE

To assess the intracranial hemodynamic modifications induced by a decompressive craniectomy (DC) after severe traumatic brain injury (TBI), using transcranial Doppler (TCD) ultrasonography and intracranial pressure (ICP) sensor. Mortality rate and neurological outcomes were also evaluated after this procedure.

DESIGN

A prospective study was carried out on 26 TBI patients, measuring transcranial Doppler and ICP before, immediately after, and 48 hours after the DC, allowing for statistical analysis of hemodynamic changes. The mortality rate and the neurological outcomes were assessed.

MEASUREMENTS AND RESULTS

After DC, ICP decreased from 37+/-17 to 20+/-13 mm Hg (P=0.0003). The global cerebral blood flow was modified with diastolic velocities rising from 23+/-15 to 31+/-13 cm/s (P=0.0038) and a pulsatility index decreasing from 1.70+/-0.66 to 1.18+/-0.37 (P=0.0012). This normalization of the global cerebral hemodynamics after the DC was immediate, symmetric, and constant during the first 48 hours. Outcome was evaluated at 6 months: good recovery or moderate disability was observed in 11 patients (42%), persistent vegetative state in 7 patients (27%), and 8 patients died (31%).

CONCLUSIONS

The DC results in a significant, immediate, and durable improvement of ICP associated with a normalization of cerebral blood flow velocities in most TBI patients with refractory intracranial hypertension.

The current status of decompressive craniectomy

Decompressive Craniectomy (DC) continues to be widely practiced but remains controversial. The procedure has its origins thousands of years ago, with early trepanation performed for a range of medical and religious reasons. We summarize the history, techniques, complications and pathophysiology and then explore in detail the recent evidence base for the most common indications for DC; Traumatic brain injury (TBI) and Cerebral infarction. An important consideration from the outset is the often forgotten issue of cranioplasty and we summarize advances in materials, technology and discuss the optimum timing. Outcomes of ongoing randomized trials in TBI are awaited with interest but the trend in the nonrandomized literature suggests timely intervention reduces mortality with acceptable morbidity. Level 1 evidence for early DC in young patients with malignant middle cerebral artery infarction has arrived and has implications for neurosurgical practice and rehabilitation services. Current European and North American practice recommends the judicious use of DC in traumatic brain injury and malignant middle cerebral artery infarction in select patients.

Cranioplasty using polymethyl methacrylate prostheses

In this retrospective study we attempted to assess the clinical performance of prefabricated polymethyl methacrylate (PMMA) prostheses and to determine whether they outperform intra-operatively moulded PMMA prostheses in reducing operating time, blood loss and surgical complications in elective delayed cranioplasty operations, after decompressive craniectomy, to repair large (> 100 cm2) cranial defects. Patients (n=131) were divided into three groups according to the cranioplasty technique used. Group 1 patients received fresh frozen autograft bone that had been removed at the craniectomy and refrigerated at -80 degrees C. Group 2 included patients whose PMMA prosthesis was moulded intra-operatively. Group 3 patients received a custom-made prefabricated PMMA prosthesis manufactured using computer-aided design/computer-aided manufacturing (CAD/CAM). Group 2 patients required significantly more operating time than both group 1 (p<0.001) and group 3 (p<0.001) patients, but operating time did not differ significantly between groups 1 and 3 (p>0.05). Mean intra-operative blood loss was significantly higher in group 2 than in group 1 (p=0.015) but did not differ significantly between group 1 and group 3 (p>0.05). The infection rate associated with prefabricated PMMA prostheses was lower than that for intra-operatively moulded PMMA prostheses and was comparable to that for autograft bone flaps. A CAD/CAM PMMA prosthesis is an excellent alternative when no autogenous bone graft harvested during craniectomy is available.

Comparison of the effect of decompressive craniectomy on different neurosurgical diseases

BACKGROUND

Many previous studies have reported that decompressive craniectomy has improved clinical outcomes in patients with intractable increased intracranial pressure (ICP) caused by various neurosurgical diseases. However there is no report that compares the effectiveness of the procedure in the different conditions. The authors performed decompressive craniectomy following a constant surgical indication and compared the clinical outcomes in different neurosurgical diseases.

MATERIALS AND METHODS

Seventy five patients who underwent decompressive craniectomy were analysed retrospectively. There were 28 with severe traumatic brain injury (TBI), 24 cases with massive intracerebral haemorrhage (ICH), and 23 cases with major infarction (MI). The surgical indications were GCS score less than 8 and/or a midline shift more than 6 mm on CT. The clinical outcomes were assessed on the basis of mortality and Glasgow Outcome Scale (GOS) scores. The changes of ventricular pressure related to the surgical intervention were also compared between the different disease groups.

FINDINGS

Clinical outcomes were evaluated 6 months after decompressive craniectomy. The mortality was 21.4% in patients with TBI, 25% in those with ICH and 60.9% in MI. A favourable outcome, i.e. GOS 4-5 (moderate disability or better) was observed in 16 (57.1%) patients with TBI, 12 (50%) with ICH and 7 (30.4%) with MI. The change of ventricular pressure after craniectomy and was 53.2 (reductions of 17.4%) and further reduced by 14.9% (with dural opening) and (24.8%) after returning to its recovery room, regardless of the diseases group.

CONCLUSIONS

According to the mortality and GOS scores, decompressive craniectomy with dural expansion was found to be more effective in patients with ICH or TBI than in the MI group. However, the ventricular pressure change during the decompressive craniectomy was similar in the different disease groups. The authors thought that decompressive craniectomy should be performed earlier for the major infarction patients.

Reversible monoparesis following decompressive hemicraniectomy for traumatic brain injury

Object

The “syndrome of the trephined” is an uncommon and poorly understood disorder of delayed neurological deficit following craniectomy. From the authors' extensive experience with decompressive hemicraniectomy for traumatic brain injury (TBI), they have encountered a number of patients who developed delayed motor deficits, also called “motor trephine syndrome,” and reversal of the weakness following cranioplasty repair. The authors set out to study motor function systematically in this patient population to define the incidence, contributing factors, and outcome of patients with motor trephine syndrome.

Methods

The authors evaluated patient demographics, injury characteristics, detailed motor examinations, and CT scans in 38 patients with long-term follow-up after decompressive hemicraniectomy for TBI.

Results

Ten patients (26%) experienced delayed contralateral upper-extremity weakness, beginning 4.9 ± 0.4 months (mean ± standard error) after decompressive hemicraniectomy. Motor deficits improved markedly within 72 hours of cranioplasty repair, and all patients recovered full motor function. The CT perfusion scans, performed in 2 patients, demonstrated improvements in cerebral blood flow commensurate with resolution of cerebrospinal fluid flow disturbances on CT scanning and return of motor strength. Comparisons between 10 patients with and 20 patients (53%) without delayed motor deficits identified 3 factors—ipsilateral contusions, abnormal cerebrospinal fluid circulation, and longer intervals to cranioplasty repair—to be strongly associated with delayed, reversible monoparesis following decompressive hemicraniectomy.

Conclusions

Delayed, reversible monoparesis, also called motor trephine syndrome, is common following decompressive hemicraniectomy for TBI. The results of this study suggest that close follow-up of motor strength with early cranioplasty repair may prevent delayed motor complications of decompressive hemicraniectomy.

Haemorrhagic infarction after autologous cranioplasty in a patient with sinking flap syndrome

Sinking flap syndrome is a potential complication of large decompressive craniectomies that usually resolves completely after cranioplasty. We report a 77 year-old female who underwent an autologous cranioplasty to treat a sinking flap syndrome. In the first post-operative day she developed a large hemispheric haemorrhagic infarction. In this report we discuss the possible pathogenic mechanism of such a complication.

Survey of management of severe head injury in Canada

OBJECTIVE

To determine: 1. the degrees of consensus and disagreement among Canadian critical care clinicians regarding the appropriateness (benefit exceeding risk) of common therapeutic manoeuvres in patients with severe closed head injury (CHI), and 2. the frequency with which clinicians employed these manoeuvres.

METHODS

The study design was a systematic scenario-based survey of all neurosurgeons and critical care physicians treating patients with severe CHI in Canada.

RESULTS

In the scenario of acute epidural hematoma with mass effect, respondents agreed very strongly that surgery was appropriate. Clinicians reported mannitol and hypertonic saline as appropriate. Beyond these two interventions, agreement was less strong, and the use of the extraventricular drain (EVD), phenytoin, cooling, hyperventilation, nimodipine, and jugular venous oximetry (JVO) were of uncertain appropriateness. Steroids were considered inappropriate. In a scenario of diffuse axonal injury (DAI), clinicians agreed strongly that fever reduction, early enteral feeding, intensive glucose control, and cerebral perfusion pressure (CPP)-directed management were appropriate. The use of mannitol, hypertonic saline, EVD, JVO, narcotics and propofol were also appropriate. Neuromuscular blockade, surgery, and hyperventilation were of uncertain appropriateness. The appropriateness ratings of the interventions considered in the scenario of an intracranial contusion mirrored the DAI scenario. In general, correlations between the reported appropriateness and frequency of use of each intervention were very high. An exception noted was the use of the JVO. The correlation between CPP-guided therapy and the use of the EVD was weak.

CONCLUSIONS

This survey has described current practice with regard to treatment of patients with severe CHI. Areas of variation in perceived appropriateness were identified that may benefit from further evaluation. Suggested priorities for evaluation include the use of osmotic diuretics, anticonvulsants, and intracranial manometry.

The role of surgery in traumatic brain injury

PURPOSE OF REVIEW

To identify the surgical indications in the treatment of posttraumatic intracranial hematomas and to evaluate the role of external decompression in severe posttraumatic intracranial hypertension.

RECENT FINDINGS

An evidence-based review resulted recently in the publication of Guidelines for Surgical Management of Traumatic Brain Injury. Unfortunately all published surgical studies are at the level of simple options with no standards. We know that a number of patients harbouring small epidural/subdural hematomas can be managed conservatively when the lesions are less than 10 mm of thickness and with a midline shift of less than 5 mm. With exception of these few cases, the current practice is that a large number of patients with posttraumatic hematomas are operated either within 24 h from injury (with acute subdural hematomas as the prevailing lesion) or later (with parenchymal hematomas as the prevailing lesion). According to a recent European study, about one third of these patients are also decompressed.

SUMMARY

A surgical approach is frequent in posttraumatic intracranial hematomas in spite of a low level of evidence. One of the surgical options either in association with hematoma evacuation or in isolation is the technique of bone flap decompression.

Treatment leading to dramatic recovery in acute hemorrhagic leukoencephalitis

The clinical course, neuroimaging, neuropathological features, and management of a 7-year-old girl with acute hemorrhagic leukoencephalitis are reported. Treatment with subtotal bifrontal craniectomies for symptoms of imminent uncal herniation followed by high-dose corticosteroid therapy was associated with dramatic clinical recovery. This report highlights the utility of aggressive intervention in acute hemorrhagic leukoencephalitis, an otherwise fatal disorder.

Craniectomie décompressive et hypertension intracrânienne

Decompressive craniectomy was purposed for the treatment of refractory intracranial hypertension after head injury. This review discusses results obtained by this surgery in severe head trauma. Several studies have confirmed a reduction in intracranial pressure secondary to decompressive craniectomy. Mortality decreased and the proportion of good outcome of the survivors increased. These results have not been confirmed prospectively, and indications have to be clarified. The positive effects of decompressive craniectomy compared to barbiturate or hypocapnia in the "second tier therapy" in refractory intracranial hypertension could be interesting to evaluate.

Effect of Early and Delayed Decompressive Craniectomy on Secondary Brain Damage after Controlled Cortical Impact in Mice

The timing of decompressive craniectomy for the treatment of increased intracranial pressure (ICP) after traumatic brain injury (TBI) is a widely discussed clinical issue. Although we showed recently that early decompression is beneficial following experimental TBI, it remains unclear to what degree decompression craniectomy reduces secondary brain damage and if craniectomy is still beneficial when it is delayed by several hours as often inevitable during daily clinical practice. The aim of the current study was therefore to investigate the influence of craniectomy on secondary contusion expansion and brain edema formation and to determine the therapeutic window of craniectomy. Male C57/Bl6 mice were subjected to controlled cortical impact injury. Contusion volume, brain edema formation, and opening of the blood-brain barrier were investigated 2, 6, 12, and 24 h and 7 days after trauma. The effect of decompression craniectomy on secondary brain damage was studied in control mice (closed skull) and in animals craniotomized immediately or with a delay of 1, 3, or 8 h after trauma. Twenty-four hours after trauma, the time point of maximal lesion expansion (+60% vs. 15 min after trauma) and brain edema formation (+3.0% water content vs. sham), contusion volume in craniotomized mice did not show any secondary expansion; that is, contusion volume was similar to that observed in mice sacrificed immediately after trauma (18.3 +/- 5.3 vs. 22.2 +/- 1.4 mm(3)). Furthermore, brain edema formation was reduced by 52% in craniotomized animals. The beneficial effect of craniectomy was still present even when treatment was delayed by up to 3 h after trauma (p < 0.05). The current study clearly demonstrates that early craniectomy prevents secondary brain damage and significantly reduces brain edema formation after experimental TBI. Evaluation of early craniectomy as a therapeutic option after TBI in humans may therefore be indicated.

Decompressive craniectomy for the treatment of refractory high intracranial pressure in traumatic brain injury

BACKGROUND

High intracranial pressure (ICP) is the most frequent cause of death and disability after severe traumatic brain injury (TBI). High ICP is treated by general maneuvers (normothermia, sedation etc) and a set of first line therapeutic measures (moderate hypocapnia, mannitol etc). When these measures fail to control high ICP, second line therapies are started. Among these, second line therapies such as barbiturates, hyperventilation, moderate hypothermia or removal of a variable amount of skull bone (known as decompressive craniectomy) are used.

OBJECTIVES

To assess the effects of secondary decompressive craniectomy (DC) on outcome and quality of life in patients with severe TBI in whom conventional medical therapeutic measures have failed to control raised ICP.

SEARCH STRATEGY

We searched the Cochrane Injuries Group's Trial Register, CENTRAL, MEDLINE, EMBASE, Best Evidence, Clinical Practice Guidelines, PubMed, CINAHL, the National Research Register and Google Scholar. We also handsearched relevant conference proceedings and contacted experts in the field and the authors of included studies.

SELECTION CRITERIA

Randomized or quasi-randomized studies assessing patients over the age of 12 months with a severe TBI who underwent DC to control ICP refractory to conventional medical treatments.

DATA COLLECTION AND ANALYSIS

Two authors independently examined the electronic search results for reports of possibly relevant trials and for retrieval in full. One author applied the selection criteria, performed the data extraction and assessed methodological quality. Study authors were contacted for additional information.

MAIN RESULTS

We found one trial with 27 participants conducted in the pediatric population (>18 years). DC was associated with a risk ratio (RR) for death of 0.54 (95% CI 0.17 to 1.72), and RR of 0.54 for death, vegetative status or severe disability 6 to 12 months after injury (95% CI 0.29 to 1.07).

AUTHORS' CONCLUSIONS

There is no evidence to support the routine use of secondary DC to reduce unfavourable outcome in adults with severe TBI and refractory high ICP. In the pediatric population DC reduces the risk of death and unfavourable outcome. Despite the wide confidence intervals for death and the small sample size of the only study identified, this treatment maybe justified in patients below the age of 18 when maximal medical treatment has failed to control ICP. To date, there are no results from randomised trials to confirm or refute the effectiveness of DC in adults. However, the results of non-randomized trials and controlled trials with historical controls involving adults, suggest that DC may be a useful option when maximal medical treatment has failed to control ICP. There are two ongoing randomized controlled trials of DC (Rescue ICP and DECRAN) that may allow further conclusions on the efficacy of this procedure in adults.