Early postoperative complications following neurosurgical procedures

Multimodal Intraoperative Neurophysiological Monitoring in Cranial and Spinal Tumour Surgeries: A Descriptive Observational Study

Intraoperative neurophysiological monitoring (IONM) involves monitoring the functional integrity of critical brain regions and pathways as well as identifying and preserving functionally viable neural tissues (mapping) during surgery using electrophysiological techniques. Multimodality combines various neurophysiological techniques to optimise diagnostic effectiveness and to improve the outcomes of the surgeries. The present study is a case series with comprehensive and illustrative descriptions of the neurophysiological changes in five neuromonitored cases of cranial and spinal cord tumour surgeries conducted with a multimodal approach. The cases were monitored with somatosensory evoked potentials (SSEP), transcranial motor evoked potentials (TcMEP), and both free run and triggered electromyography (fEMG and tEMG). No false negative outcomes were identified in the cases studied as there was an association of absence of change in SSEP and TcMEP both, with no neurological deficit postoperatively. Two cases were identified as having true positive neuromonitoring alerts. No false positive alerts were found in any case. Multimodal monitoring using SSEP, TcMEP, and EMG (fEMG and tEMG) in cranial and spinal tumour surgeries can improve performance with fewer false-negative and false-positive results. Neuromonitoring approaches used in combination can provide reliable information regarding postoperative neurological outcomes.

Effects of goal-directed fluid management guided by a non-invasive device on the incidence of postoperative complications in neurosurgery: a pilot and feasibility randomized controlled trial

BACKGROUND

The positive effects of goal-directed hemodynamic therapy (GDHT) on patient-orientated outcomes have been demonstrated in various clinical scenarios; however, the effects of fluid management in neurosurgery remain unclear. Therefore, this study was aimed at assessing the safety and feasibility of GDHT using non-invasive hemodynamic monitoring in elective neurosurgery. The incidence of postoperative complications was compared between GDHT and control groups.

METHODS

We conducted a single-center randomized pilot study with an enrollment target of 34 adult patients scheduled for elective neurosurgery. We randomly assigned the patients equally into control and GDHT groups. The control group received standard therapy during surgery and postoperatively, whereas the GDHT group received therapy guided by an algorithm based on non-invasive hemodynamic monitoring. In the GDHT group, we aimed to achieve and sustain an optimal cardiac index by using non-invasive hemodynamic monitoring and bolus administration of colloids and vasoactive drugs. The number of patients with adverse events, feasibility criteria, perioperative parameters, and incidence of postoperative complications was compared between groups.

RESULTS

We successfully achieved all feasibility criteria. The GDHT protocol was safe, because no patients in either group had unsatisfactory brain tissue relaxation after surgery or brain edema requiring therapy during surgery or 24 h after surgery. Major complications occurred in two (11.8%) patients in the GDHT group and six (35.3%) patients in the control group (p = 0.105).

CONCLUSIONS

Our results suggested that a large randomized trial evaluating the effects of GDHT on the incidence of postoperative complications in elective neurosurgery should be safe and feasible. The rate of postoperative complications was comparable between groups.

TRIAL REGISTRATION

Trial registration: ClininalTrials.gov, registration number: NCT04754295, date of registration: February 15, 2021.

Postoperative surveillance in cranial and spinal tumor neurosurgery: when is this warranted?

OBJECTIVE

The outbreak of COVID-19 and the sudden increase in the number of patients requiring mechanical ventilation significantly affected the management of neurooncological patients. Hospitals were forced to reallocate already scarce human resources to maximize intensive care unit (ICU) capacities, resulting in a significant postponement of elective procedures for patients with brain and spinal tumors, who traditionally require elective postoperative surveillance on ICU or intermediate care wards. This study aimed to characterize those patients in whom postoperative monitoring is required by analyzing early postoperative complications and associated risk factors.

METHODS

All patients included in the analysis experienced benign or malignant cerebral or intradural tumors and underwent surgery between September 2017 and May 2019 at University Hospital Münster, Germany. Patient data were generated from a semiautomatic, prospectively designed database. The occurrence of adverse events within 24 hours and 30 days postoperatively-including unplanned reoperation, postoperative hemorrhage, CSF leakage, and pulmonary embolism-was chosen as the primary outcome measure. Furthermore, reasons and risk factors that led to a prolonged stay on the ICU were investigated. By performing multivariable logistic regression modeling, a risk score for early postoperative adverse events was calculated by assigning points based on beta coefficients.

RESULTS

Eight hundred eleven patients were included in the study. Eleven patients (1.4%) had an early adverse event within 24 hours, which was either an unplanned reoperation (0.9%, n = 7) or a pulmonary embolism (0.5%, n = 4) within 24 hours. To predict the incidence of early postoperative complications, a score was developed including the number of secondary diagnoses, BMI, and incision closure time, termed the SOS score. According to this score, 0.3% of the patients were at low risk, 2.5% at intermediate risk, and 12% at high risk (p < 0.001).

CONCLUSIONS

Postoperative surveillance in cranial and spinal tumor neurosurgery might only be required in a distinct patient collective. In this study, the authors present a new score allowing efficient prediction of the likelihood of early adverse events in patients undergoing neurooncological procedures, thus helping to stratify the necessity for ICU or intermediate care unit beds. Nevertheless, validation of the score in a multicenter prospective setting is needed.

Inhibition of LRRK2-Rab10 Pathway Improves Secondary Brain Injury After Surgical Brain Injury in Rats

Leucine-rich repeat kinase 2 (LRRK2) is considered as a potential target for the treatment of Parkinson's disease. This protein is expressed in the brain and has been associated with various diseases and lysosomal maintenance. Rab10 is a member of the Rab protein GTPase family that has been recently shown to be a kinase substrate of LRRK2. In addition, LRRK2 and its kinase substrate Rab10 constitute a key stress response pathway during lysosomal overload stress. This study aimed to investigate the potential role and mechanism underlying LRRK2 and its kinase substrate Rab10 involving surgical brain injury (SBI). One hundred and forty-four male Sprague-Dawley rats were examined using an SBI model, and some had received the LRRK2-specific inhibitor PF-06447475. Thereafter, western blotting, immunofluorescence, brain water content analysis, neuronal apoptosis assay, and neurological score analysis were conducted. The results showed that after SBI, LRRK2 and phosphorylated Rab10 (p-Rab10) expression in neuronal cells were upregulated, and administration of PF-06447475 significantly reduced neuronal apoptosis, neuroinflammation, and brain water content 12 h after SBI and improved neurological deficit 72 h after SBI, which is related to the decreased expression of LRRK2 and p-Rab10, and the lessening of lysosomal overload stress. Our research suggests that the inhibition of LRRK2 can effectively interfere with the role of p-Rab10 in promoting the secretion of lysosomal hydrolase in lysosomal overload stress after SBI, thereby reducing neuronal apoptosis and inflammation after SBI and playing a major role in brain protection.

Neurologic Complications in the Postoperative Neurosurgery Patient

PURPOSE OF REVIEW

This article discusses neurologic complications encountered in the postoperative care of neurosurgical patients that are common or key to recognize in the immediate postoperative period. The major neurosurgical subspecialty procedures (cerebrovascular neurosurgery, neuro-oncology, epilepsy neurosurgery, functional neurosurgery, CSF diversion, endovascular neurosurgery, and spinal surgery) are broadly included under craniotomy procedures, endovascular/vascular procedures, and spinal procedures. This article focuses on the range of complications inherent in these approaches with specific scenarios addressed as applicable.

RECENT FINDINGS

The morbidity and mortality related to neurosurgical procedures remains high, necessitating ongoing research and quality improvement efforts in perioperative screening, intraoperative management, surgical approaches, and postoperative care of these patients. Emerging research continues to investigate safer and newer options for routine neurosurgical approaches, such as coiling over clipping for amenable aneurysms, endoscopic techniques for transsphenoidal hypophysectomy, and minimally invasive spinal procedures; postoperative monitoring and care of patients after these procedures continues to be a key component in the continuum of care for improving outcomes.

SUMMARY

Postoperative care of patients undergoing major neurosurgical procedures is an integral part of many neurocritical care practices. Neurosurgeons often enlist help from neurologists to assist with evaluation, interpretation, and management of complications in routine inpatient settings. Awareness of the common neurologic complications of various neurosurgical procedures can help guide appropriate clinical monitoring algorithms and quality improvement processes for timely evaluation and management of these patients.

Frequency of early postoperative adverse events (AEs) in adult patients undergoing elective neurosurgical intervention at tertiary care center in Pakistan

Objective:

The postoperative period is critical in neurosurgical patients, where the incidence of postoperative AEs is significantly high. Most of events occurs during recovery phase and has got relation to anaesthetic management. The objective of study was to determine frequency of early AEs in elective neurosurgical patients.

Methods:

This cross sectional study was conducted at our tertiary care center. The duration of study was one year, from August 2017-July 2018. The data was collected using predesigned proforma. The assessment was done on arrival in recovery room (T1) and then at forty five minutes (T2), twenty-fourth hour (T3) and forty-eighth hour (T4) postoperatively.

Results:

Total ninety-five patients were included. Overall, five hundred and forty AEs were recorded at T1, T2, T3 and T4. Anaesthesia related events like pain, postoperative sore throat, hoarseness, shivering and hypothermia were the commonest (73%). There was a gradual decline in incidence of these events over period of 48 hours. There was no effect of age, sex, BMI and blood loss on incidence of AEs.

Conclusions:

Postoperative pain, PONV and shivering were frequently reported AEs. We did not identify the impact of age, sex, BMI, comorbid or type of surgery in terms of having these events.

Dietary nutrition for neurological disease therapy: Current status and future directions

Adequate food intake and relative abundance of dietary nutrients have undisputed effects on the brain function. There is now substantial evidence that dietary nutrition aids in the prevention and remediation of neurologic symptoms in diverse pathological conditions. The newly described influences of dietary factors on the alterations of mitochondrial dysfunction, epigenetic modification and neuroinflammation are important mechanisms that are responsible for the action of nutrients on the brain health. In this review, we discuss the state of evidence supporting that distinct dietary interventions including dietary supplement and dietary restriction have the ability to tackle neurological disorders using Alzheimer's disease, Parkinson's disease, stroke, epilepsy, traumatic brain injury, amyotrophic lateral sclerosis, Huntington's disease and multiple sclerosis as examples. Additionally, it is also highlighting that diverse potential mechanisms such as metabolic control, epigenetic modification, neuroinflammation and gut-brain axis are of utmost importance for nutrient supply to the risk of neurologic condition and therapeutic response. Finally, we also highlight the novel concept that dietary nutrient intervention reshapes metabolism-epigenetics-immunity cycle to remediate brain dysfunction. Targeting metabolism-epigenetics-immunity network will delineate a new blueprint for combating neurological weaknesses.

Real-Time Intraoperative Pressure Monitoring to Avoid Surgically Induced Localized Brain Injury Using a Miniaturized Piezoresistive Pressure Sensor

Neurosurgical procedures often cause damage to the brain tissue at the periphery from surgical manipulations. Especially during retraction, a large amount of pressure could be applied on the brain surface, which can damage it, leading to brain herniation, which can be fatal for patients. To resolve this issue, we have developed a pressure sensor that can be used to monitor the applied pressure during surgery for intraoperative care. This device was tested on a rodent model to create a superficial surgically induced damage profile for three different applied pressures (30, 50, and 70 mmHg) and compared to a standard intracranial pressure monitoring system. Magnetic resonance imaging has been performed after surgical procedures to detect the herniation caused by applied pressure. To evaluate the damage to brain cells and tissue rupture, histological analysis was performed using hematoxylin and eosin staining. A scoring system was developed to understand the severity of the surgically induced brain injury, which will help neurosurgeons to limit the pressure to an optimum point without causing damage.

Efficacy of routine post-operative head computed tomography on cranial surgery patients outcome

Objectives:

To identify the role of routine postoperative head CT in changing postoperative management after elective craniotomies.

Methods:

We conducted a retrospective study on adult patients who underwent cranial surgery. Exclusion criteria includes cranial CTs done postoperatively for urgent clinical indications, pediatric patients, CSF diversion procedures and sedated patients. Patients were placed into “positive” group if the physical assessment changed from the baseline in the form of clinical deterioration, and the “negative” group if the exam did not change. The data then were analyzed to identify which patients needed further medical or surgical management based on CT findings only with “negative” physical examination.

Results:

Total of 222 were included in the study. 151 patients had negative physical examination. Only 8 out of 151 patients had positive CT findings. Two patients out of 222 (0.9%) had a negative physical exam and positive CT findings that required additional action that wouldn’t be done urgently without routine postoperative brain CT. Only one patient out of 222 (0.4%) who was re-operated urgently based CT findings only and negative physical examination.

Conclusion:

Routine postoperative routine brain CT did not alter the course of medical management, even in the presence of significant radiological findings.

The Activation of Phosphatidylserine/CD36/TGF-β1 Pathway prior to Surgical Brain Injury Attenuates Neuroinflammation in Rats

Neuroinflammation plays an important pathological role in experimental surgical brain injury (SBI). Apoptotic associated with phosphatidylserine (PS) externalization promotes anti-inflammatory mediator TGF-β1 release. In the present study, we investigated the anti-neuroinflammation effect of PS liposome or isoflurane pretreatment via PS/CD36/TGF-β1 signaling in a rat model of SBI. A total of 120 male Sprague-Dawley rats (weighing 280-330 gms) were used. SBI was induced by partial right frontal lobe corticotomy. Intranasal PS liposome or isoflurane inhalation was administered prior to SBI induction. CD36 small interfering RNA (siRNA) was administered intracerebroventricularly. Recombinant Annexin V protein (rAnnexin V) was delivered intranasally. Post-SBI assessments included neurological tests, brain water content, Western blot, and immunohistochemistry. Endogenous CD36 protein levels but not TGF-β1 was significantly increased within peri-resection brain tissues over 72 h after SBI. SBI rats were associated with increased brain water content surrounding corticotomy and neurological deficits. PS liposome pretreatment significantly reduced brain water content and improved some neurological deficits at 24 hours and 72 hours after SBI. PS liposome increased CD36 and TGF-β1 protein levels, but decreased IL-1β and TNFα protein levels in peri-resection brain tissues at 24 hours after SBI. CD36 siRNA or rAnnexin V partially countered the protective effect of PS liposome. Isoflurane pretreatment produced similar antineuroinflammation and neurological benefits in SBI rats partially by upregulating CD36/Lyn/TGF-β1 signaling. Collectively, our findings suggest that the activation of PS/CD36/TGF-β1 pathway by PS liposome or isoflurane prior to SBI could attenuate neuroinflammation and improve neurological outcomes in rats. PS liposome or isoflurane pretreatment may serve as an effective preventive strategy to minimize the brain injury caused by neurosurgical procedures in patients.

Perioperative Stroke

PURPOSE OF REVIEW

This review overviews perioperative stroke as it pertains to specific surgical procedures.

RECENT FINDINGS

As awareness of perioperative stroke increases, so does the opportunity to potentially improve outcomes for these patients by early stroke recognition and intervention. Perioperative stroke is defined to be any stroke that occurs within 30 days of the initial surgical procedure. The incidence of perioperative stroke varies and is dependent on the specific type of surgery performed. This chapter overviews the risks, mechanisms, and acute evaluation and management of perioperative stroke in four surgical populations: cardiac surgery, carotid endarterectomy, neurosurgery, and non-cardiac/non-carotid/non-neurological surgeries.

Surgically-induced brain injury: where are we now?

Neurosurgical procedures cause inevitable brain damage from the multitude of surgical manipulations utilized. Incisions, retraction, thermal damage from electrocautery, and intraoperative hemorrhage cause immediate and long-term brain injuries that are directly linked to neurosurgical operations, and these types of injuries, collectively, have been termed surgical brain injury (SBI). For the past decade, a model developed to study the underlying brain pathologies resulting from SBI has provided insight on cellular mechanisms and potential therapeutic targets. This model, as seen in a rat, mouse, and rabbit, mimics a neurosurgical operation and causes commonly encountered post-operative complications such as brain edema, neuroinflammation, and hemorrhage. In this review, we elaborate on SBI and its clinical impact, the SBI animal models and their clinical relevance, the importance of applying therapeutics before neurosurgical procedures (i.e., preconditioning), and the new direction of applying venom-derived proteins to attenuate SBI.

Modification of kynurenine pathway via inhibition of kynurenine hydroxylase attenuates surgical brain injury complications in a male rat model

Neurosurgical procedures result in surgically induced brain injury (SBI) that causes postoperative complications including brain edema and neuronal apoptosis in the surrounding brain tissue. SBI leads to the release of cytokines that indirectly cause the stimulation of kynurenine 3-monooxygenase (KMO) and the release of neurotoxic quinolinic acid (QUIN). This study tested a KMO inhibitor, RO 61-8048, to prevent postoperative brain edema and consequent neuronal apoptosis in an in vivo model of SBI. A rodent model of SBI was utilized which involves partial resection of the right frontal lobe. A total of 127 Sprague-Dawley male rats (weight 275-325 g) were randomly divided into the following groups: Sham surgical group, SBI, SBI + DMSO, SBI + RO 61-8048 (10 mg/kg), SBI + RO 61-8048 (40 mg/kg), and SBI + RO 61-8048 (40 mg/kg) + KAT II inhibitor PF-04859989 (5 mg/kg). RO 61-8048 was administered by intraperitoneal injection after SBI. Postoperative assessment at different time points included brain water content (brain edema), neurological scoring, and western blot. SBI increased brain water content (ipsilateral frontal lobe), decreased neurological function, and increased apoptotic markers compared with sham animals. Treatment with RO 61-8048 (40 mg/kg) reduced brain water content and improved long-term neurological function after SBI. RO 61-8048 increased the expression of kynurenic acid while reducing QUIN and apoptotic markers in the surrounding brain tissue after SBI. These neuroprotective effects were reversed by PF-04859989. This study suggests KMO inhibition via RO 61-8048 as a potential postoperative therapy following neurosurgical procedures.

Recent Trends in Electively Treated Unruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE

To determine recent treatment and outcome trends in patients undergoing elective surgical clipping (SC) or endovascular therapy (EVT) for unruptured intracranial aneurysms (UIAs) in the United States.

METHODS

Data were extracted and analyzed from the National Inpatient Sample, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality for all patients admitted for elective EVT or SC of UIAs between 2011 and 2014. Treatment trends, in-hospital mortality, complication rates, length of stay (LOS) and total hospital costs were evaluated and analyzed.

RESULTS

A total of 31,070 patients with UIAs were included in our analysis, of which 14,411 and 16,659 underwent elective SC and EVT, respectively. There was no significant difference in in-hospital mortality rates between the 2 groups. EVT was associated with lower in-hospital complication rates, decreased median LOS (.8 days versus 3.3 days, P ≤ .0001), and an increased likelihood of discharge to home (92.9% versus 72.9%, P = .0001). Median total hospital charges were similar in both treatment cohorts. Independent predictors of mortality in the elective population were age over 40 years (P ≤ .0001), weekend treatment (P ≤ .0001), and high co-morbidity status (P ≤ .0001).

CONCLUSIONS

In-hospital mortality rates were similar in elective EVT and SC UIA patients; however, EVT was associated with lower in-hospital complication rates and shorter LOS.

Incidence and predictors of postoperative pulmonary complications in patients undergoing craniotomy and excision of posterior fossa tumor

Background and Aims:

Infratentorial neurosurgical procedures are considered high risk for the development of postoperative pulmonary complications (POPCs), prolonging hospital stay of patients with substantial morbidity and mortality.

Material and Methods:

Patients between the ages of 18 and 65 years, who underwent elective surgery for posterior fossa tumors over a period of two years, were reviewed. Data including American Society of Anesthesiologists physical status; comorbidities like hypertension, diabetes mellitus and hypothyroidism, history of smoking, obstructive sleep apnea, respiratory symptoms, lower cranial nerve (LCN) palsy; intraoperative complications such as hemodynamic alterations suggestive of brain stem or cranial nerve handling, tight brain as informed by the operating neurosurgeon, blood loss, and transfusion; and postoperative duration of mechanical ventilation, tracheostomy, POPCs, length of ICU and hospital stay, general condition of the patient at discharge, and cause of in-hospital mortality were collected. POPC was defined as the presence of atelectasis, tracheobronchitis, pneumonia, bronchospasm, respiratory failure, reintubation, or weaning failure.

Results:

Case files of 288 patients fulfilling the study criteria were analyzed; POPCs were observed in 35 patients (12.1%). On multivariate analysis, postoperative blood transfusion, LCN palsy, prolonged ICU stay, and tracheostomy were found to be independent predictors of POPC.

Conclusions:

The incidence of POPC was 12.1% following infratentorial tumor surgery. The predictors for the occurrence of POPCs were postoperative blood transfusion, LCN palsy, prolonged ICU stay, and tracheostomy.

Prediction Score for Postoperative Neurologic Complications after Brain Tumor Craniotomy

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Craniotomy for brain tumor displays significant morbidity and mortality, and no score is available to discriminate high-risk patients. Our objective was to validate a prediction score for postoperative neurosurgical complications in this setting.

Methods

Creation of a score in a learning cohort from a prospective specific database of 1,094 patients undergoing elective brain tumor craniotomy in one center from 2008 to 2012. The validation cohort was validated in a prospective multicenter independent cohort of 830 patients from 2013 to 2015 in six university hospitals in France. The primary outcome variable was postoperative neurologic complications requiring in–intensive care unit management (intracranial hypertension, intracranial bleeding, status epilepticus, respiratory failure, impaired consciousness, unexpected motor deficit). The least absolute shrinkage and selection operator method was used for potential risk factor selection with logistic regression.

Results

Severe complications occurred in 125 (11.4%) and 90 (10.8%) patients in the learning and validation cohorts, respectively. The independent risk factors for severe complications were related to the patient (Glasgow Coma Score before surgery at or below 14, history of brain tumor surgery), tumor characteristics (greatest diameter, cerebral midline shift at least 3 mm), and perioperative management (transfusion of blood products, maximum and minimal systolic arterial pressure, duration of surgery). The positive predictive value of the score at or below 3% was 12.1%, and the negative predictive value was 100% in the learning cohort. In–intensive care unit mortality was observed in eight (0.7%) and six (0.7%) patients in the learning and validation cohorts, respectively.

Conclusions

The validation of prediction scores is the first step toward on-demand intensive care unit admission. Further research is needed to improve the score’s performance before routine use.

Effects of Intraoperative Dexamethasone and Ondansetron on Postoperative Nausea and Vomiting in Microvascular Decompression Surgery: A Randomized Controlled Study

Background

Postoperative nausea and vomiting (PONV) is a common problem and may lead to catastrophic complications, especially in neurosurgical cases. The aim of this study was to evaluate the effects of dexamethasone and ondansetron for preventing PONV in patients who underwent microvascular decompression (MVD) surgery.

Methods

A prospective, double-blinded, randomized control trial was conducted with 54 patients who underwent MVD. Patients were allocated into two groups. The study group (Gr. D) received intraoperative dexamethasone 4 mg iv and ondansetron 4 mg iv, whereas the control group (Gr. N) received placebo (0.9% normal saline 1 ml iv and 0.9% normal saline 2 ml iv). The incidence and severity of PONV were observed at 1, 2, 4, and 24 hr postsurgery.

Results

At 1, 2, 4, and 24 hr postsurgery, Gr. D had a lower incidence (7.4%, 11.1%, 29.6%, and 66.7%) and lower severity of PONV than Gr. N (18.5%, 29.6%, 37.0%, and 81.5% at 1, 2, 4, and 24 hr; p > 0.05). The requirement for antiemetic drugs was not significantly different between the groups (p > 0.05).

Conclusion

Administration of dexamethasone and ondansetron 4 mg seemed to decrease the incidence of PONV in the first 24 hours but not significantly. Therefore, further studies are to be carried out by escalating either dexamethasone dose or the dose of ondansetron or both.

Milk Fat Globule-Epidermal Growth Factor-8 Pretreatment Attenuates Apoptosis and Inflammation via the Integrin-β3 Pathway after Surgical Brain Injury in Rats

Iatrogenic brain injury inevitably occurs in neurosurgical operations, leading to brain edema, ischemia, intracranial hematoma, and other postoperative complications, eventually worsening neurological outcomes of patients. If apoptotic cells are not rapidly eliminated by phagocytic engulfment, they may communicate with surrounding cells to undergo secondary necrosis and releasing toxic signals. Recent studies have shown that milk fat globule-epidermal growth factor-8 (MFGE8), which promotes phagocytosis and inhibits inflammation, is an endogenous protective factor in response to brain infarction, Alzheimer’s disease, subarachnoid hemorrhage, and prion disease. In the present study, we sought to investigate the different effects of both pretreated and posttreated recombinant milk fat globule-epidermal growth factor-8 (rhMFGE8) for the surgical brain injury (SBI) rat model and potential involvement of its receptor integrin β3 for apoptosis and neuroinflammation after SBI. One hundred and sixty-seven male rats were employed in the preset study. Experiment 1 was performed to evaluate neurological scores and MFGE8, cleaved caspase-3 (CC3), and interleukine-1 beta (IL-1β) levels at 3, 24, and 120 h after SBI. Experiment 2 was performed to evaluate the effects of rhMFGE8 pretreatment (10 min before SBI) and rhMFGE8 posttreatment (6 h after SBI) on brain edema at 24 and 72 h after SBI. Experiment 3 was performed to evaluate the potential anti-apoptotic and anti-inflammatory effects of rhMFGE8 pretreatment and posttreatment. Experiment 4 sought to investigate the involvement of the integrin-β3 signal in the effects of MFGE8 pretreatment. Our data showed rhMFGE8 pretreatment alleviated neurological deficits and decreased brain water content and apoptotic cells in the SBI model, which exhibited neurological dysfunction, apoptosis, and inflammation. Meanwhile, MFGE8 siRNA, which inhibited endogenous MFGE8 expression, significantly increased IL-1β, TUNEL positive cells, and CC3. Furthermore, knockdown of its receptor integrin β3 by siRNA abolished the effects of rhMFGE8 in the SBI model. In conclusion, we found that rhMFGE8 pretreatment effectively alleviated neurological deficits and decreased brain water content and apoptotic cells in the SBI model through the MFGE8/integrin-β3 pathway, and treatment time was an important factor in achieving curative effects. Therefore, MFGE8 pretreatment may serve as a promising therapeutic strategy for SBI patients.

Use of Dexmedetomidine for Prophylactic Analgesia and Sedation in Patients With Delayed Extubation After Craniotomy: A Randomized Controlled Trial

Background:

We conducted a randomized trial to evaluate the efficacy and safety of dexmedetomidine for prophylactic analgesia and sedation in patients with delayed extubation after craniotomy.

Methods:

From June 2012 to July 2014, 150 patients with delayed extubation after craniotomy were randomized 1:1 and were assigned to the dexmedetomidine group that received a continuous infusion of 0.6 μg/kg/h (10 μg/mL) or the control group that received a maintenance infusion of 0.9% sodium chloride for injection. The mean percentage of time under optimal sedation (SAS3-4), the percentage of patients who required rescue with propofol/fentanyl, and the total dose of propofol/fentanyl required throughout the course of drug infusion, as well as VAS, HR, MAP, and SpO₂ were recorded.

Results:

The percentage of time under optimal sedation was significantly higher in the dexmedetomidine group than in the control group (98.4%±6.7% vs. 93.0%±16.2%, P=0.008). The VAS was significantly lower in the dexmedetomidine group than in the control group (1.0 vs. 4.0, P=0.000). The HR and mean BP were significantly lower in the dexmedetomidine group than in the control group at all 3 time points (before endotracheal suctioning, immediately after extubation, and 30 min after extubation). No significant difference in SpO₂ was observed between the 2 groups. For hemodynamic adverse events, patients in the dexmedetomidine group were more likely to develop bradycardia (5.3% vs. 0%, P=0.043) but had a lower likelihood of tachycardia (2.7% vs. 18.7%, P=0.002).

Conclusions:

Dexmedetomidine may be an effective prophylactic agent to induce sedation and analgesia in patients with delayed extubation after craniotomy. The use of dexmedetomidine (0.6 μg/kg/h) infusion does not produce respiratory depression, but may increase the incidence of bradycardia.

Predicting complication risk in spine surgery: a prospective analysis of a novel risk assessment tool

OBJECTIVE The ability to assess the risk of adverse events based on known patient factors and comorbidities would provide more effective preoperative risk stratification. Present risk assessment in spine surgery is limited. An adverse event prediction tool was developed to predict the risk of complications after spine surgery and tested on a prospective patient cohort. METHODS The spinal Risk Assessment Tool (RAT), a novel instrument for the assessment of risk for patients undergoing spine surgery that was developed based on an administrative claims database, was prospectively applied to 246 patients undergoing 257 spinal procedures over a 3-month period. Prospectively collected data were used to compare the RAT to the Charlson Comorbidity Index (CCI) and the American College of Surgeons National Surgery Quality Improvement Program (ACS NSQIP) Surgical Risk Calculator. Study end point was occurrence and type of complication after spine surgery. RESULTS The authors identified 69 patients (73 procedures) who experienced a complication over the prospective study period. Cardiac complications were most common (10.2%). Receiver operating characteristic (ROC) curves were calculated to compare complication outcomes using the different assessment tools. Area under the curve (AUC) analysis showed comparable predictive accuracy between the RAT and the ACS NSQIP calculator (0.670 [95% CI 0.60-0.74] in RAT, 0.669 [95% CI 0.60-0.74] in NSQIP). The CCI was not accurate in predicting complication occurrence (0.55 [95% CI 0.48-0.62]). The RAT produced mean probabilities of 34.6% for patients who had a complication and 24% for patients who did not (p = 0.0003). The generated predicted values were stratified into low, medium, and high rates. For the RAT, the predicted complication rate was 10.1% in the low-risk group (observed rate 12.8%), 21.9% in the medium-risk group (observed 31.8%), and 49.7% in the high-risk group (observed 41.2%). The ACS NSQIP calculator consistently produced complication predictions that underestimated complication occurrence: 3.4% in the low-risk group (observed 12.6%), 5.9% in the medium-risk group (observed 34.5%), and 12.5% in the high-risk group (observed 38.8%). The RAT was more accurate than the ACS NSQIP calculator (p = 0.0018). CONCLUSIONS While the RAT and ACS NSQIP calculator were both able to identify patients more likely to experience complications following spine surgery, both have substantial room for improvement. Risk stratification is feasible in spine surgery procedures; currently used measures have low accuracy.

Technical assessment of a prototype cone-beam CT system for imaging of acute intracranial hemorrhage

PURPOSE

A cone-beam CT scanner has been developed for detection and monitoring of traumatic brain injury and acute intracranial hemorrhage (ICH) at the point of care. This work presents a technical assessment of imaging performance and dose for the scanner in phantom and cadaver studies as a prerequisite to clinical translation.

METHODS

The scanner incorporates a compact, rotating-anode x-ray source and a flat-panel detector (43 × 43 cm²) on a mobile U-arm gantry with source-axis distance = 550 mm and source-detector distance = 1000 mm. Central and peripheral doses were measured in 16 cm diameter CTDI phantoms using a 0.6 cm³ Farmer ionization chamber for various scan techniques and as a function of longitudinal position, including out of field. Spatial resolution, contrast, noise, and image uniformity were assessed in quantitative and anthropomorphic head phantoms. Two reconstruction protocols were evaluated, including filtered backprojection (FBP) for high-resolution bone imaging and penalized weighted least squares (PWLS) reconstruction for low-contrast soft tissue (ICH) visualization. A fresh cadaver was imaged with and without simulated ICH using the scanner as well as a diagnostic multidetector CT (MDCT) scanner using a standard head protocol. Images were interpreted by a fellowship-trained neuroradiologist for imaging tasks of ICH detection, gray-white-CSF differentiation, detection of midline shift, and fracture detection.

RESULTS

The nominal scan protocol involved 720 projections acquired over a 360° orbit at 100 kV and 216 mAs, giving a dose (weighted CTDI) of 22.8 mGy (∼1.2 mSv effective dose). Out-of-field dose decreased to <10% within 6 cm of the field edge (approximate to the thyroid position). Image uniformity demonstrated <1% variation between the edge of the field (near the cranium) and center of the image. The high-resolution FBP reconstruction protocol showed ∼0.9 mm point spread function (PSF) full-width at half-maximum (FWHM). The smooth PWLS reconstruction protocol yielded ∼1.2 mm PSF FWHM and contrast-to-noise ratio exceeding 5.7 in ∼50 HU spherical ICH, resulting in conspicuous depiction of ICH down to ∼2 mm (the smallest diameter investigated). Cadaver images demonstrated good differentiation of brain and CSF (sufficient, but inferior to MDCT, recognizing that the CBCT dose was one-third that of MDCT), excellent visualization of cranial sutures and fracture (potentially superior to MDCT), clear detection of midline shift, and conspicuous detection of ICH.

CONCLUSIONS

Technical assessment of the prototype demonstrates dose characteristics and imaging performance consistent with point-of-care detection and monitoring of head injury-most notably, conspicuous detection of ICH-and supports translation of the system to clinical studies.

Postoperative complications after craniotomy for brain tumor surgery

INTRODUCTION

After elective craniotomy for brain tumour surgery, patients are usually admitted to an intensive care unit (ICU) for monitoring. Our goal was to evaluate the incidence and timing of neurologic and non-neurologic postoperative complications after brain tumour surgery, to determine factors associated with neurologic events and to evaluate the timing and causes of ICU readmission.

PATIENTS AND METHODS

This prospective, observational and analytic study enrolled 188 patients admitted to the ICU after brain tumour surgery. All postoperative clinical events during the first 24hours were noted and classified. Readmission causes and timing were also analysed.

RESULTS

Twenty-one (11%) of the patients were kept sedated after surgery; the remaining 167 patients were studied. Thirty one percent of the patients presented at least one complication (25% with postoperative nausea and vomiting (PONV), 16% with neurologic complications). The occurrence of neurological complications was significantly associated with the absence of preoperative motor deficit and the presence of higher intraoperative bleeding. Seven patients (4%) were readmitted to the ICU after discharge; 43% (n=3) of them had a posterior fossa surgery.

CONCLUSION

Postoperative complications, especially PONV, are frequent after brain tumour surgery. Moreover, 16% of patients presented a neurological complication, probably justifying the ICU postoperative stay for early detection. The absence of preoperative motor deficit and intraoperative bleeding seems to predict postoperative neurologic complications. Finally, patients may present complications after ICU discharge, especially patients with fossa posterior surgery, suggesting that ICU hospitalization may be longer in this type of surgery.

Postoperative Care Following Pituitary Surgery

Patients undergoing surgery for pituitary tumors represent a heterogeneous population each with unique clinical, biochemical, radiologic, pathologic, neurologic, and/or ophthalmologic considerations. The postoperative management of patients following pituitary surgery often occurs in the context of a dynamic state of the hypothalamic-pituitary-end organ axis. Consequently, a significant component of the postoperative care of these patients focuses on vigilant screening and observation for neuroendocrinologic perturbations such as varying degrees of hypopituitarism and disorders of water balance (diabetes insipidus and the syndrome of inappropriate antidiuretic hormone). Additionally, one must be cognizant of other potential complications specific to the transsphenoidal approach for tumor removal including cerebrospinal fluid leakage and meningitis. This review addresses the postoperative management of patients undergoing pituitary surgery with an emphasis on careful screening and recognition of complications.

Central hyperventilation syndrome due to massive pneumocephalus after endoscopic third ventriculostomy: a case report

Pneumocephalus is common after brain surgeries, but usually is not substantial enough to cause serious complications. We recently encountered a case of post-operative tachypnea after an endoscopic 3rd ventriculostomy. At first, we thought that the hyperventilation was the result of residual paralysis after emergence from anesthesia, but during further evaluation we found a massive pneumocephalus. In such unusual post-operative situations, physicians should consider surgery-related complications as the possible cause as well, along with the anesthetic factors.

Phosphoinositide 3-Kinase Gamma Contributes to Neuroinflammation in a Rat Model of Surgical Brain Injury

Neuroinflammation plays an important role in the pathophysiology of surgical brain injury (SBI). Phosphoinositide 3-kinase gamma (PI3Kγ), predominately expressed in immune and endothelial cells, activates multiple inflammatory responses. In the present study, we investigated the role of PI3Kγ and PI3Kγ-activated phosphodiesterase 3B (PDE3B) in neuroinflammation in a rat model of SBI. One hundred and fifty-two male Sprague Dawley rats (weight 280-350 g) were subjected to a partial right frontal lobe corticotomy model of SBI. A PI3Kγ pharmacological inhibitor (AS252424 or AS605240) was administered intraperitoneally. PI3Kγ siRNA, human recombinant active-PI3Kγ protein, or human recombinant active-PDE3B protein were administered intracerebroventricularly. Post-SBI assessments included neurobehavioral tests, brain water content, Western blot, and immunohistochemistry. Endogenous PI3Kγ levels were increased within peri-resection brain tissues after SBI, accompanied by increased brain water content and neurological functional deficits. There was a trend toward increased endogenous PDE3B phosphorylation after SBI. The selective PI3Kγ inhibitors AS252424 and AS605240 reduced brain water content surrounding corticotomy and improved neurological function after SBI. SBI increased and PI3Kγ inhibitor decreased levels of myeloperoxidase, cluster of differentiation 3, mast cell degranulation, E-selectin, and IL-1 in peri-resection brain tissues. Direct administration of human recombinant active-PI3Kγ protein and active-PDE3B protein countered the protective effect of AS252424. PI3Kγ siRNA reduced PI3Kγ levels, decreased brain water content within peri-resection brain tissues, and improved neurological function after SBI. Collectively, our findings suggest that PI3Kγ contributed to neuroinflammation after SBI. The use of selective PI3Kγ inhibitors may be a novel approach to ameliorating SBI via their anti-inflammation effects. Significance statement: Life-saving or elective neurosurgeries often involve unavoidable damages to neighboring, nondiseased brain tissues. Such surgical brain injury (SBI) is attributable exclusively to the neurosurgical procedure itself and may cause postoperative complications that exacerbate neurological function. Although the importance of this medical problem is fully acknowledged, intraoperative administration of adjunctive treatment such as steroids and mannitol to patients undergoing neurosurgery appear not to be efficient remedies for SBI. To date, the issue of perioperative neuroprotection specifically against SBI has not been well studied. Using a clinically relevant rat model of SBI, we are exploring a new neuroprotective strategy targeting phosphoinositide 3-kinase gamma (PI3Kγ). PI3Kγ activates multiple inflammatory responses. By attenuating neuroinflammation, selective PI3Kγ inhibition would limit postoperative complications and benefit neurological outcomes.

Minimizing Collateral Brain Injury Using a Protective Layer of Fibrin Glue: Technical Note

BACKGROUND

Neurosurgical procedures expose the brain surface to a constant risk of collateral injury. We describe a technique where the brain surface is covered with a protective layer of fibrin glue and discuss its advantages.

METHODS

A thin layer of fibrin glue was applied on the brain surface after its exposure in 34 patients who underwent different craniotomies for tumoral and vascular lesions. Data of 35 more patients who underwent standard microsurgical technique were collected as a control group. Cortical and pial injuries were evaluated using an intraoperative visual scale. Eventual abnormal signals at the early postoperative T2-weighted fluid-attenuated inversion recovery (T2FLAIR) magnetic resonance imaging (MRI) sequences were evaluated in oncological patients.

RESULTS

Total pial injury was noted in 63% of cases where fibrin glue was not used. In cases where fibrin glue was applied, a significantly lower percentage of 26% (P < 0.01) had pial injuries. Only 9% had injuries in areas covered with fibrin glue (P < 0.0001). Early postoperative T2FLAIR MRI confirmed the differences of altered signal around the surgical field in the two populations.

CONCLUSION

We propose beside an appropriate and careful microsurgical technique the possible use of fibrin glue as alternative, safe, and helpful protection during complex microsurgical dissections. Its intrinsic features allow the neurosurgeon to minimize the cortical manipulation preventing minor collateral brain injury.

Triple Therapy with Scopolamine, Ondansetron, and Dexamethasone for Prevention of Postoperative Nausea and Vomiting in Moderate to High-Risk Patients Undergoing Craniotomy Under General Anesthesia: A Pilot Study

Introduction

Postoperative nausea and vomiting (PONV) is one of the most common complaints from patients and clinicians after a surgical procedure. According to the current Society of Ambulatory Anesthesia Consensus Guidelines, the general incidence of vomiting and nausea is around 30 and 50%, respectively; and up to 80% in high-risk patients. In previous studies, the reported incidence of PONV at 24 h after craniotomy was 43–70%. The transdermal scopolamine (TDS) delivery system contains a 1.5-mg drug reservoir, which is designed to deliver a continuous slow release of scopolamine through intact skin during the first 72 h of patch application. Therefore, we designed this single arm, non-randomized, pilot study to assess the efficacy and safety of triple therapy with scopolamine, ondansetron, and dexamethasone to prevent PONV.

Materials and methods

In the preoperative area, subjects received an active TDS 1.5 mg that was applied to a hairless patch of skin in the mastoid area approximately 2 h prior to the operation. Immediately after anesthesia induction, all patients received a single 4 mg dose of ondansetron IV and a single 10 mg dose of dexamethasone IV. Patients who experienced nausea and/or vomiting received ondansetron 4 mg IV as the initial rescue medication. Postoperative nausea and vomiting assessments were performed for up to 120 h after surgery.

Results

A total of 36 subjects were analyzed. The overall incidence of PONV during the first 24 h after neurological surgery was 33% (n = 12). The incidence of nausea and emesis during the first 24 h after surgery was recorded as 33% (n = 12) and 16% (n = 6), respectively.

Conclusion

Our data showed that this triple therapy regimen may be an efficient alternative regimen for PONV prophylaxis in patients undergoing neurological surgery with general anesthesia. Further studies using regimens affecting different receptor pathways should be performed to better prove the efficacy and safety in the prevention or delay of PONV.

Incidence, Risk Factors and Consequences of Emergence Agitation in Adult Patients after Elective Craniotomy for Brain Tumor: A Prospective Cohort Study

Emergence agitation is a frequent complication that can have serious consequences during recovery from general anesthesia. However, agitation has been poorly investigated in patients after craniotomy. In this prospective cohort study, adult patients were enrolled after elective craniotomy for brain tumor. The sedation-agitation scale was evaluated during the first 12 hours after surgery. Agitation developed in 35 of 123 patients (29%). Of the agitated patients, 28 (80%) were graded as very and dangerously agitated. By multivariate stepwise logistic regression analysis, independent predictors for agitation included male sex, history of long-term use of anti-depressant drugs or benzodiazepines, frontal approach of the operation, method and duration of anesthesia and presence of endotracheal intubation. Total intravenous anesthesia and balanced anesthesia with short duration were protective factors. Emergence agitation was associated with self-extubation (8.6% vs 0%, P = 0.005). Sedatives were administered more in agitated patients than non-agitated patients (85.7% vs 6.8%, P<0.001). In conclusion, emergence agitation was a frequent complication in patients after elective craniotomy for brain tumors. The clarification of risk factors could help to identify the high-risk patients, and then to facilitate the prevention and treatment of agitation. For patients undergoing craniotomy, greater attention should be paid to those receiving a frontal approach for craniotomy and those anesthetized under balanced anesthesia with long duration. More researches are warranted to elucidate whether total intravenous anesthesia could reduce the incidence of agitation after craniotomy.

Trial Registration

ClinicalTrials.gov NCT00590499.

Immediate postoperative complications in transsphenoidal pituitary surgery: A prospective study

BACKGROUND

Considering the important role of pituitary gland in regulating various endocrine axes and its unique anatomical location, various postoperative complications can be anticipated resulting from surgery on pituitary tumors. We examined and categorized the immediate postoperative complications according to various tumor pathologies.

MATERIALS AND METHODS

We carried out a prospective study in 152 consecutive patients and noted various postoperative complications during neurosurgical intensive care unit stay (within 48 hrs of hospital stay) in patients undergoing transsphenoidal removal of pituitary tumors.

RESULTS

In our series, various groups showed different postoperative complications out of which, cerebrospinal fluid leak was the commonest followed by diabetes insipidus, postoperative nausea and vomiting, and hematoma at operation site.

CONCLUSION

Various immediate postoperative complications can be anticipated in transsphenoidal pituitary surgery even though, it is considered to be relatively safe.

Risk factors of postoperative pulmonary complications following elective craniotomy for patients with tumors of the brainstem or adjacent to the brainstem

The aim of the present study was to analyze the risk factors of postoperative pulmonary complications (PPCs) of elective craniotomy for patients presenting with brainstem tumors or tumors adjacent to the brainstem. A total of 162 consecutive patients with a brainstem tumor or adjacent brainstem tumor undergoing elective craniotomy were included and monitored. Potential risk factors were identified by data collection and monitoring of the PPCs, as well as the performance of single factor analysis (using the χ² test). In addition, the independent risk factors of PPCs were screened by logistic analysis. A total of 39 cases of PPC were included in the current study, with an incidence rate of 23.9%. The analysis indicated that smoking history, previous pulmonary diseases, an American Society of Anesthesiologists classification >II and partial tumor resection were risk factors of PPC following an elective craniotomy. Smoking history and partial tumor resection were identified to be independent risk factors of PPCs.

Indication for surgery and the risk of postoperative nausea and vomiting after craniotomy: a case-control study

BACKGROUND

The primary hypothesis of the study is that acoustic neuroma (AN) surgery and microvascular decompression (MVD) of cranial nerves increase the risk of postoperative nausea and vomiting (PONV).

METHODS

We designed a retrospective case-control study matched on age, sex, and year of surgery (≤2005 and >2005). Year of surgery was noted as a potential confounder, because routine antiemetic prophylaxis was strongly encouraged at the study site in 2005. Cases of PONV in the recovery room were matched to controls in a 1:2 manner using a perioperative database. Charts were then reviewed for the following data: American Society of Anesthesiologists grade, smoking status, craniotomy location, craniotomy indication, and type of anesthetic administered.

RESULTS

The final analysis included 117 cases that were matched with 185 controls. Patients had a mean age of 50 years (SD=13), and 65% were female. Overall, the majority of craniotomies were supratentorial (70%) and performed for tumor resection (41%). On multivariable analysis, MVD [odds ratio (OR)=6.7; 95% confidence interval (CI), 2.0-22.7; P=0.002], AN (OR=3.3; 95% CI, 1.0-11.0; P=0.05), and epilepsy surgery (OR=2.8; 95% CI, 1.1-7.5; P=0.04) were associated with an increased likelihood of PONV when compared with tumor surgery. There was effect modification of total intravenous anesthesia by location of surgery (P-interaction=0.02). The benefit of total intravenous anesthesia on PONV was observed in supratentorial (OR=0.41; 95% CI, 0.17-0.96; P=0.04) but not infratentorial location (OR=2.6; 95% CI, 0.78-8.7; P=0.11).

CONCLUSIONS

MVD and AN resection were associated with an increased likelihood of PONV compared with craniotomies performed for other tumor resection.

Postoperative nausea and vomiting in patients after craniotomy: incidence and risk factors

OBJECT

The purpose of this study was to assess the incidence and risk factors of postoperative nausea and vomiting (PONV) after craniotomy because most available data about PONV in neurosurgical patients are retrospective in nature or derive from small prospective studies.

METHODS

Postoperative nausea and vomiting was prospectively assessed within 24 hours after surgery in 229 patients requiring supratentorial or infratentorial craniotomy. To rule out the relevance of the neurosurgical procedure itself to the development of PONV, the observed incidence of vomiting was compared with the rate of vomiting predicted with a surgery-independent risk score (Apfel postoperative vomiting score).

RESULTS

The overall incidence of PONV after craniotomy was 47%. Logistic regression identified female sex as a risk factor for postoperative nausea (OR 4.25, 95% CI 2.3-7.8) and vomiting (OR 2.62, 95% CI 1.4-4.9). Both the incidence of nausea (OR 3.76, 95% CI 2.06-6.88) and vomiting (OR 4.48, 95% CI 2.4-8.37) were increased in patients not receiving steroids. Postoperative nausea and vomiting occurred after infratentorial as well as after supratentorial procedures. The observed incidence of vomiting within 24 hours after surgery was higher (49%) than would be predicted with the Apfel surgery-independent risk score (31%; p = 0.0004).

CONCLUSIONS

The overall incidence of PONV within 24 hours after craniotomy was approximately 50%. One possible reason is that intracranial surgeries pose an additional and independent risk factor for vomiting, especially in female patients. Patients undergoing craniotomy should be identified as high-risk patients for PONV.

Effects of propofol sedation during the early postoperative period in hemorrhagic stroke patients

BACKGROUND

The early postoperative period is a critical time for patients after receiving a decompressive craniotomy. Prompt detection and early management of postoperative recurrent/residual hemorrhagic complications may dramatically improve clinical outcomes.

METHODS

The present cohort retrospective study involved 135 patients who received decompressive craniotomy and intensive care unit (ICU) supervision as life-saving measures. The purpose of the study was to evaluate the effects of propofol sedation on the clinical outcome during the ICU stay. The patients' demographic data, hemodynamic variables, the dose of propofol used during the first 48 hours after surgery, residual/recurrent blood clot volume after surgery, and neurologic and clinical outcomes were reviewed. The propofol dosages used for sedation were further divided into three categories: < 0.66, 0.66-3.33 and > 3.33 mg/kg/hr, based on the doses infused during the first 12 hours after surgery.

RESULTS

Our results indicated that the patients of the propofol-sedated group had a significantly smaller amount of residual/recurrent blood clot (p < 0.05) than did those of the non-sedated group. The 30-day mortality rate was significantly lower in the propofol-sedated group (p < 0.05) than in the non-sedated group. Among the propofol-sedated patients, those who received a dose of 0.66-3.33 mg/kg/hr in the first 12 hours after surgery achieved significantly improved clinical and neurologic outcomes than those who received either more than 3.33 mg/kg/hr or less than 0.66 mg/kg/hr of propofol.

CONCLUSION

Our results support the use of propofol sedation during the early postoperative period after craniotomy in hemorrhagic stroke patients, because it improved both neurologic and clinical outcomes. However, early postoperative use of propofol sedation at larger dosages warrants special attention.

Dual effects of melatonin on oxidative stress after surgical brain injury in rats

The purpose of this study was to evaluate the effect of melatonin on oxidative stress occurring in the brain after routine lobectomy neurosurgery procedures. Different concentrations of melatonin (5, 15 and 150 mg/kg) were administered 1 hr before lobectomy in a rodent surgical brain injury (SBI) model. Neurological outcomes were assessed 24 hr before the killing of the rodents, for evaluation of brain water content (brain edema) and lipid peroxidation (oxidative stress). The results showed that lower doses (5 and 15 mg/kg) failed to reduce brain edema, but the 15 mg/kg dose did lower oxidative stress and improved several neurological parameters. High concentration of melatonin (150 mg/kg) significantly increased brain edema and elevated oxidative stress when compared with the vehicle-treated group. Furthermore, high-dose melatonin also worsened neurological outcomes compared with other groups. The study suggests that melatonin has dual effects: low-dose melatonin may provide neuroprotective effects against SBI but a high dose may aggravate some parameters after SBI.

Incidence and risk factors for postoperative pulmonary complications in elective intracranial surgery

OBJECT

It has been shown that craniotomy may lead to a decrease in lung volumes and arterial blood gas tensions as well as a change in the respiratory pattern. The purpose of this study was to determine the incidence of postoperative pulmonary complications (PPCs) and the mortality rate in patients who have undergone elective craniotomy and to evaluate the associations between preoperative and postoperative variables and PPCs in this population.

METHODS

Two hundred thirty-six patients were followed up based on a protocol including a clinical questionnaire, physical examination and observation of clinical characteristics in the preoperative period, type of surgery performed, duration of surgery, time spent in the intensive care unit (ICU) and hospital, and the occurrence of any PPCs.

RESULTS

Postoperative pulmonary complications occurred in 58 patients (24.6%) and 23 other patients (10%) died. Predicting factors for PPCs according to multivariate analyses were as follows: type of surgery performed (p < 0.0001), prolonged mechanical ventilation >or= 48 hours (p < 0.0001), time spent in the ICU > 3 days (p < 0.0001), decrease in level of consciousness (p < 0.002), duration of surgery >or= 300 minutes (p < 0.01), and previous chronic lung disease (p < 0.04).

CONCLUSIONS

The incidence from March 2003 to March 2005 of PPCs in patients who had undergone craniotomy was 25% and death occurred in 10%. Some risk factors for PPCs may be predicted such as the type of surgery performed, prolonged mechanical ventilation, a longer time in the ICU, a decreased level of consciousness, duration of surgery, and previous chronic lung disease.

Rosiglitazone, a PPAR gamma agonist, attenuates inflammation after surgical brain injury in rodents

INTRODUCTION

Surgical brain injury (SBI) is unavoidable during many neurosurgical procedures. This inevitable brain injury can result in post-operative complications including brain edema, blood-brain barrier disruption (BBB) and cell death in susceptible areas. Rosiglitazone (RSG), a PPAR-gamma agonist, has been shown to reduce inflammation and provide neuroprotection in experimental models of ischemia and intracerebral hemorrhage. This study was designed to evaluate the neuroprotective effects of RSG in a rodent model of SBI.

METHODS

65 adult male Sprague-Dawley rats were randomly divided into sham, vehicle and treatment groups. RSG was administered intraperitoneally in two dosages (1 mg/kg/dose, 6 mg/kg/dose) 30 min before surgery, and 30 min and 4 h after surgery. Animals were euthanized 24 h following neurological evaluation to assess brain edema and BBB permeability by IgG staining. Inflammation was examined using myeloperoxidase (MPO) assay and double-labeling fluorescent immunohistochemical analysis of IL-1beta and TNF-alpha.

RESULTS

Localized brain edema was observed in tissue surrounding the surgical injury. This brain edema was significantly higher in rats subjected to SBI than sham animals. Increased IgG staining was present in affected brain tissue; however, RSG reduced neither IgG staining nor brain edema. RSG also did not improve neurological status observed after SBI. RSG, however, significantly attenuated MPO activity and qualitatively decreased IL-1beta and TNF-alpha expression compared to vehicle-treated group.

CONCLUSION

SBI causes increased brain edema, BBB disruption and inflammation localized along the periphery of the site of surgical resection. RSG attenuated inflammatory changes, however, did not improve brain edema, BBB disruption and neurological outcomes after SBI.

Matrix metalloproteinase inhibition attenuates brain edema in an in vivo model of surgically-induced brain injury

OBJECTIVE

Neurosurgical procedures can result in brain injury by various means, including direct trauma, hemorrhage, retractor stretch, and electrocautery. This surgically-induced brain injury (SBI) can cause postoperative complications such as brain edema after blood-brain barrier (BBB) disruption. The present study seeks to test a matrix metalloproteinase (MMP) inhibitor for preventing postoperative brain edema and BBB disruption in an in vivo model of surgically-induced brain injury.

METHODS

A rodent model of SBI was used which involves resection of a part of the right frontal lobe. A total of 89 Sprague-Dawley male rats (weight, 300-350 g) were randomly divided into four groups: 1) SBI with vehicle treatment (0.1% dimethyl sulfoxide), 2) SBI with single treatment of MMP inhibitor-1 (an inhibitor of MMP-9 and MMP-2), 3) SBI treated daily (total 3 times) with MMP inhibitor-1, and 4) sham surgical group. Postoperative assessment at different time periods included evaluation of BBB permeability, brain water content (brain edema), neurological scoring, histology, immunohistochemistry, and zymography for MMP enzymatic activity. Temporal magnetic resonance imaging studies were also performed to assess postoperative edema.

RESULTS

The results indicate that SBI caused increased brain water content (ipsilateral frontal lobe) and BBB permeability compared with sham animals. Treatment with MMP inhibitor-1 attenuated MMP-9 and MMP-2 activity and decreased brain water content with preservation of the BBB.

CONCLUSION

Inhibition of MMP-9 and MMP-2 attenuates brain edema and BBB disruption after SBI. The study suggests a potential role for MMP inhibition as preoperative therapy before neurosurgical procedures.

Matrix metalloproteinase inhibition attenuates brain edema after surgical brain injury

BACKGROUND

Neurosurgical operations can result in inevitable brain injury due to the procedure itself. This surgical brain injury (SBI) can cause post-operative complications such as brain edema following blood-brain barrier (BBB) disruption leading to neurological deficits.

METHODS

We tested whether inhibition of matrix metalloproteinases (MMPs) 9 and 2 provided neuroprotection against SBI. A rodent SBI model, which involves a partial frontal lobe resection, was used to evaluate two treatment regimens of MMP inhibitor-1 (inhibitor of MMP-9 and MMP-2); a single dose (5 mg/kg, pretreatment) and daily dose treatment (5 mg/kg x 3, pre- and post-treatment). Postoperative assessment at different time periods included brain water content (brain edema), immunohistochemical analysis, zymography for MMP enzymatic activity, and neurological assessment.

FINDINGS

The results indicate that SBI caused localized edema around the site of surgical resection with concomitant increase in MMP-9 and MMP-2 activity. Both treatment regimens with MMP inhibitor-1 decreased brain edema and attenuated the rise in MMP-9 and MMP-2 activity. An increased expression of MMP-9 was also seen in the neurons and neutrophils in the affected brain tissue at the periphery of surgical resection.

CONCLUSIONS

The study suggests a potential role for MMP inhibition as preoperative therapy before neurosurgical procedures.