Epidural hematoma in patients with ankylosing spondylitis requiring surgical stabilization: a single-institution retrospective review with literature analysis

OBJECTIVE

Ankylosing spondylitis (AS) is a chronic inflammatory disease affecting the sacroiliac joints and axial spine that is closely linked with human leukocyte antigen-B27. There appears to be an increased frequency of associated epidural hematomas in spine fractures in patients with AS. The objective was to review the incidence within the literature and a single-institution experience of the occurrence of epidural hematoma in the context of patients with AS requiring spine surgery.

METHODS

Deep 6 AI software was used to search the entire database of patients at a single level I trauma center (since the advent of the institution's modern electronic health record system) to look at all patients with AS who underwent spinal surgery and who had a diagnosis of epidural hematoma. Additionally, a systemic literature review was performed of all papers evaluating the incidence of epidural hematoma in patients with spine fractures.

RESULTS

A single-institution, retrospective review of records from 2009 to 2020 yielded a total of 164 patients with AS who underwent spine surgery. Of those patients, 17 (10.4%) had epidural hematomas on imaging, with the majority requiring surgical decompression. These spine fractures occurred close to the cervicothoracic or thoracolumbar junction. The patients ranged in age from 51 to 88 years, and there were 14 males and 3 females in the cohort. Eight patients were administered an antiplatelet and/or anticoagulant agent, and the rest were not. All patients required surgical stabilization, with 64.7% of patients also requiring decompressive laminectomies for evacuation of the hematoma and spinal cord decompression. Only 1 death was reported in the series. There was a tendency toward neurological improvement after surgical intervention.

CONCLUSIONS

AS has been a well-described pathologic process that leads to an increased risk of three-column injury in spine fracture, with an increased incidence of symptomatic epidural hematoma compared with patients without AS. Early recognition of this entity is important to ensure that appropriate surgical management includes addressing compression of the neural elements in addition to surgical stabilization.

Endothelial KCa 1.1 and KCa 3.1 channels mediate rat intrarenal artery endothelium-derived hyperpolarization response

AIM

Endothelium-derived hyperpolarization (EDH)-mediated response plays an essential role in the control of kidney preglomerular circulation, but the identity of the K⁺ channels involved in this response is still controversial. We hypothesized that large- (K_Ca 1.1), intermediate- (K_Ca 3.1) and small (K_Ca 2.3) -conductance Ca²⁺ -activated K⁺ (K_Ca ) channels are expressed in the endothelium of the preglomerular circulation and participate in the EDH-mediated response.

METHODS

We study the functional expression of different K⁺ channels in non-cultured, freshly isolated native endothelial cells (ECs) of rat intrarenal arteries using immunofluorescence and the patch-clamp technique. We correlate this with vasorelaxant responses ex vivo using wire myography.

RESULTS

Immunofluorescence revealed the expression of K_Ca 1.1, K_Ca 3.1 and K_Ca 2.3 channels in ECs. Under voltage-clamp conditions, acetylcholine induced a marked increase in the outward currents in these cells, sensitive to the blockade of K_Ca 1.1, K_Ca 3.1 and K_Ca 2.3 channels respectively. Isometric myography experiments, under conditions of endothelial nitric oxide synthase and cyclooxygenase inhibition, showed that blockade either of K_Ca 1.1 or K_Ca 3.1 channels was able to reduce the endothelium-derived vasorelaxation of isolated interlobar arteries, while their combined blockade completely abolished it. In contrast, blockade of K_Ca 2.3 channels did not reduce this vasorelaxant response, despite being functionally expressed in the endothelial cells.

CONCLUSION

This study shows that K_Ca 1.1 and K_Ca 3.1 channels are functionally expressed at the renal vascular endothelium and play a central role in the EDH-mediated relaxation of kidney preglomerular arteries, which is important in the control of renal blood flow and glomerular filtration rate.

Role of follow-up CT scans in the management of traumatic pediatric epidural hematomas

INTRODUCTION

Management of pediatric epidural hematoma (PEDH) ranges from observation to emergent craniotomy. Guidelines for management remain poorly defined. More so, serial CT imaging in the pediatric population is often an area of controversy given the concern for excessive radiation as well as increased costs. This work aims to further elucidate the need for serial imaging to surgical decision-making.

METHODS

A prospectively maintained single-institution trauma database was reviewed at a level-1 trauma center to identify patients 18 years old and younger presenting with PEDH over a 10-year period. Selected charts were reviewed for demographic information, mechanisms of injury, neurologic exam, radiographic findings, and treatment course. Surgical decisions were at the discretion of the neurosurgeon on call, often in discussion with a pediatric neurosurgeon.

RESULTS

Two hundred and ten records with traumatic epidural hematomas were reviewed. Seventy-three (35%) were taken emergently for hematoma evacuation. Of these, 18 (25%) underwent repeat imaging prior to surgery. One hundred and thirty-seven (65%) were admitted for observation. Seventy-two patients (53%) did not undergo repeat imaging. Sixty-five (47%) admitted for conservative management had at least one repeat scan during their hospitalization. Indications for follow-up imaging during conservative management included routine follow-up (74%), initial scan in our system following transfer (17%), neurological decline (8%), and unknown (1%). Thirteen patients (9%) were taken for surgery in a delayed fashion following admission. Twelve patients who went to surgery in a delayed fashion demonstrated progression on follow-up imaging; however, increase in hematoma size on repeat imaging was the sole surgical indication in only four patients (3%). There were no deaths related to the epidural hemorrhage or postoperatively, regardless of management, and all patients recovered to their pre-trauma baseline.

CONCLUSION

Given that isolated hematoma expansion accounted for an exceptionally small proportion of operative indications, this data suggests changes seen on CT should not be solely relied upon to dictate surgical management. The benefit of obtaining follow-up imaging must be strongly considered and weighed against the known deleterious effects of excessive radiation in pediatric patients, let alone its clinical utility.

Clinical Outcome of Epidural Hematoma Treated Surgically in the Era of Modern Resuscitation and Trauma Care

OBJECTIVE

Patients from contemporary populations with traumatic brain injury (TBI) resulting from epidural hematoma (EDH) may differ regarding age, comorbidities, and coagulation status. We therefore analyzed predictors for the clinical outcome of patients with EDH treated surgically regarding modern approaches to resuscitation and trauma care.

METHODS

A retrospective observational analysis was carried out. All patients included underwent surgery. The indication for surgery followed international guidelines. Retrospective data evaluation considered data reflecting the effectiveness of trauma care, baseline characteristics, and radiologic findings. In this analysis, we divided patients into 2 groups (isolated EDH vs. EDH plus other intracranial traumatic injuries). The neurologic outcome was assessed at discharge using the Glasgow Outcome Scale.

RESULTS

Two hundred and sixty-eight patients with epidural hematoma, of whom 131 underwent surgery, were treated between January 1997 and December 2012 in our level-1 trauma center. The overall mortality was 6.8% (mortality for patients with Glasgow Outcome Scale score <9, 15%). As expected, factors with a highly significant (P < 0.01) impact on outcome were concomitant with other intracranial injuries, brain midline shift, and higher Injury Severity Score. Alcohol intoxication was a significant (P < 0.05) predictor of an unfavorable outcome. Anticoagulants and Glasgow Coma Scale score at admission had no significant impact on the outcome.

CONCLUSIONS

The outcome for EDH is more favorable than decades ago, most probably reflecting a well-established chain of trauma care. Therefore, EDH is a treatable disease with a high probability of a favorable outcome.

Traumatic brain injury in Indian children

INTRODUCTION

Traumatic brain injury (TBI) in children and adolescents is a community-based medical and educational challenge world-over due to increasing urbanization and motorization. In India, children between 1 to 15 years constitute significant proportion of the total population, who are vulnerable for TBI. In developed countries, pediatric trauma mortality still represents more than half of all childhood fatalities, which is 18 times more common than brain tumors. In this study, we attempted to analyze epidemiological factors, management, and outcome of TBI in children at a tertiary care center in Pune, Maharashtra.

AIM AND OBJECTIVES

To study the clinical spectrum of pediatric traumatic brain injury cases received at a Tertiary Care Hospital.

MATERIALS AND METHODS

This prospective study (August 2015-July 2017), conducted at our institution, includes all children < 16 years with TBI reporting to the neurosurgical emergency department. All the case records were reviewed and the pertinent data (clinical history, age, sex, mode of injury, computed tomography (CT) scan findings, interventions, morbidity, and mortality) analyzed. Any residual neurological deficits at the time discharge were assessed as the outcome of TBI.

RESULTS

A total 76 pediatric cases of TBI were admitted during the period of August 2015-July 2017, with 51 males (67%) and 25 females (33%) with male to female ratio 2:1. Mean age of incidence in our study is 5.5 years. Out of 76 children with TBI, 60.5% were of mild, 14.5% moderate, and 25% severe TBI. Overall, RTA (40.8%) is the most common mode of injury followed by fall from height (30.2%) and slippage in and around home (26.4%). Clinical evaluation revealed, loss of consciousness(LOC) in 36 (47.3%) patients, vomiting in 42 (55%) patients, headache in 10 (13%) patients, ENT bleeding in 18 (23.6%), and seizure in 16 (21%) patients, no external injuries in 25 (33%) patients, normal sensorium was found in 41 (54%) patients, 18 (23.6%) children were drowsy at presentation, and 17 (22.3%) children were unconscious. CT scan findings revealed no gross abnormality in (26%), extradural heamorrhage (EDH) (18.4%), subdural hemorrhage (SDH) (14.4%), subarachnoid hemorrhage (21%), fracture skull (55.26%), cerebral oedema, and contusion (48.68%) as the radiological injury patterns. Out of 76 children, 42 (55%) children are managed with only observation, 26 (34%) children required only medical pharmacological treatment, and 8 (10.5%) children required surgical intervention, 24, (31.6%) children required mechanical ventilation. Overall mortality is 5.26%. Thus among the survivors (n = 72), 57 (79%) went home with no residual deficit, 3 (4%) had headache, 4 (5.5%) had hemiparesis, 2 (2.7%) had monoparesis, 1 (1.4%) had hypertonia, 3 (4%) had seizures, 2 (2.7%) had hydrocephalus, 2 (2.7%) had facial palsy, 2 (2.7%) had vision impairment, and 2 (2.7%) had speech impairment. In our study, we found that there is a significant association between residual deficits and severity of injury (p = 0.3), there is no significant association between mode of injury and outcome (p = 0.7). Mean duration of stay in hospital was 6.9 days but 60% of patients had stay of less than 5 days.

CONCLUSION

Most of these injuries are preventable in infancy and childhood by ensuring proper vigilance, tender care by the parents and the caretakers. Safe driving techniques have to be followed by parents while traveling with children in their motor vehicles. Need to focus on grading the severity of TBI rather than on factors like age, mode of injury, and presence or absence of external injuries.

Hyperglycaemia disrupts conducted vasodilation in the resistance vasculature of db/db mice

Vascular dysfunction in small resistance arteries is observed during chronic elevations in blood glucose. Hyperglycaemia-associated effects on endothelium-dependent vasodilation have been well characterized, but effects on conducted vasodilation in the resistance vasculature are not known. Small mesenteric arteries were isolated from healthy and diabetic db/db mice, which were used as a model of chronic hyperglycaemia. Endothelium-dependent vasodilation via the G_q/11-coupled proteinase activated receptor 2 (PAR2) was stimulated with the selective agonist SLIGRL. The Ca²⁺-sensitive fluorescent indicator fluo-8 reported changes in endothelial cell (EC) [Ca²⁺]_i, and triple cannulated bifurcating mesenteric arteries were used to study conducted vasodilation. Chronic hyperglycaemia did not affect either EC Ca²⁺ or local vasodilation to SLIGRL. However, both acute and chronic exposure to high glucose or the mannitol osmotic control attenuated conducted vasodilation to 10μM SLIGRL. This investigation demonstrates for the first time that a hypertonic solution containing glucose or mannitol can interfere with the spread of a hyperpolarizing current along the endothelium in a physiological setting. Our findings reiterate the importance of studying the effects of hyperglycaemia in the vasculature, and provide the basis for further studies regarding the modulation of junctional proteins involved in cell to cell communication by diseases such as diabetes.

Changes in vasodilation following myocardial ischemia/reperfusion in rats

BACKGROUND

Blockage of a coronary artery, usually caused by arteriosclerosis, can lead to life threatening acute myocardial infarction. Opening with PCI (percutaneous coronary intervention), may be lifesaving, but reperfusion might exacerbate the cellular damage, and changes in the endothelium are believed to be involved in this worsened outcome.

AIM

The aim of the present study was to compare endothelial dependent and independent vasodilatory effect after experimental myocardial ischemia/reperfusion (I/R).

METHODS

A well-established rat model of myocardial ischemia with 24 h of reperfusion was applied, followed by a study in a wire myograph.

RESULTS

Endothelial NO dependent relaxation in response to carbachol, was sensitive to arterial depolarization, and was unaffected by I/R. In contrast, endothelial NO dependent ADPβS signalling, which was not sensitive to arterial depolarization, was significantly reduced after I/R. Following I/R, an H₂O₂ dependent EDH induced dilation appears in response to both of the above agonists. In addition, calcitonin gene-related peptide (CGRP) induced vasodilation was reduced.

CONCLUSION

These data show that NO dependent ADPβS induced dilation is reduced after I/R. However, there is some compensation by released H₂O₂ causing an EDH. Combined with a loss of maximal dilation in response to CGRP, the reduced vasodilation could be an important factor in understanding the exacerbated damage after I/R.

Regulation of KCa2.3 and endothelium-dependent hyperpolarization (EDH) in the rat middle cerebral artery: the role of lipoxygenase metabolites and isoprostanes

Background and Purpose. In rat middle cerebral arteries, endothelium-dependent hyperpolarization (EDH) is mediated by activation of calcium-activated potassium (K_Ca) channels specifically K_Ca2.3 and K_Ca3.1. Lipoxygenase (LOX) products function as endothelium-derived hyperpolarizing factors (EDHFs) in rabbit arteries by stimulating K_Ca2.3. We investigated if LOX products contribute to EDH in rat cerebral arteries.

Methods. Arachidonic acid (AA) metabolites produced in middle cerebral arteries were measured using HPLC and LC/MS. Vascular tension and membrane potential responses to SLIGRL were simultaneously recorded using wire myography and intracellular microelectrodes.

Results. SLIGRL, an agonist at PAR2 receptors, caused EDH that was inhibited by a combination of K_Ca2.3 and K_Ca3.1 blockade. Non-selective LOX-inhibition reduced EDH, whereas inhibition of 12-LOX had no effect. Soluble epoxide hydrolase (sEH) inhibition enhanced the K_Ca2.3 component of EDH. Following NO synthase (NOS) inhibition, the K_Ca2.3 component of EDH was absent. Using HPLC, middle cerebral arteries metabolized ¹⁴C-AA to 15- and 12-LOX products under control conditions. With NOS inhibition, there was little change in LOX metabolites, but increased F-type isoprostanes. 8-iso-PGF_2α inhibited the K_Ca2.3 component of EDH.

Conclusions. LOX metabolites mediate EDH in rat middle cerebral arteries. Inhibition of sEH increases the K_Ca2.3 component of EDH. Following NOS inhibition, loss of K_Ca2.3 function is independent of changes in LOX production or sEH inhibition but due to increased isoprostane production and subsequent stimulation of TP receptors. These findings have important implications in diseases associated with loss of NO signaling such as stroke; where inhibition of sEH and/or isoprostane formation may of benefit.

Emergency access to neurosurgical care for patients with traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is one of the most common causes of injury-related morbidity and mortality. Access to neurosurgical services is critical to optimal outcomes through reduction of secondary injury. We sought to evaluate variations in access to neurosurgical care across a regional trauma system.

STUDY DESIGN

This is a population-based retrospective cohort study of patients who sustained isolated severe TBI from 2005 to 2009. Administrative datasets capturing all emergency department visits and hospitalizations were linked deterministically. Differences between access to a trauma center (TC), defined as direct transport from scene or transfer from a nontrauma center (NTC) as opposed to no access, were evaluated; this included patient level determinants of access to TC and delineation of mortality differences between TC and NTC care. Transfer patterns from NTC to TC were also evaluated.

RESULTS

We identified 9,448 patients with isolated severe TBI. Almost two-thirds (60%, n = 5,701) received initial care at an NTC. Of these patients, 30% (n = 1,737) were subsequently transferred to a TC. Thirty-day mortality rates of patients treated at a TC vs NTC were 19% vs 18%, respectively (p = 0.19). Among patients younger than 65 years, 67% received TC care; only 41% of patients older than 65 were treated at a TC (p < 0.01). Mechanism, age, brain hemorrhage, and injury severity were associated with TC care.

CONCLUSIONS

Considerable variation in delivery of initial care to TBI patients was identified. Factors such as age and injury characteristics were associated with TC access. Because early TC care in TBI confers survival benefits, the demonstrated variability necessitates improvements in access to care for patients with severe head injuries.

Aronia melanocarpa juice, a rich source of polyphenols, induces endothelium-dependent relaxations in porcine coronary arteries via the redox-sensitive activation of endothelial nitric oxide synthase

This study examined the ability of Aronia melanocarpa (chokeberry) juice, a rich source of polyphenols, to cause NO-mediated endothelium-dependent relaxations of isolated coronary arteries and, if so, to determine the underlying mechanism and the active polyphenols. A. melanocarpa juice caused potent endothelium-dependent relaxations in porcine coronary artery rings. Relaxations to A. melanocarpa juice were minimally affected by inhibition of the formation of vasoactive prostanoids and endothelium-derived hyperpolarizing factor-mediated responses, and markedly reduced by N(ω)-nitro-l-arginine (endothelial NO synthase (eNOS) inhibitor), membrane permeant analogs of superoxide dismutase and catalase, PP2 (Src kinase inhibitor), and wortmannin (PI3-kinase inhibitor). In cultured endothelial cells, A. melanocarpa juice increased the formation of NO as assessed by electron paramagnetic resonance spectroscopy using the spin trap iron(II)diethyldithiocarbamate, and reactive oxygen species using dihydroethidium. These responses were associated with the redox-sensitive phosphorylation of Src, Akt and eNOS. A. melanocarpa juice-derived fractions containing conjugated cyanidins and chlorogenic acids induced the phosphorylation of Akt and eNOS. The present findings indicate that A. melanocarpa juice is a potent stimulator of the endothelial formation of NO in coronary arteries; this effect involves the phosphorylation of eNOS via the redox-sensitive activation of the Src/PI3-kinase/Akt pathway mostly by conjugated cyanidins and chlorogenic acids.

Local, integrated control of blood flow: Professor Tudor Griffith Memorial

Professor Tudor Griffith was one of the founding members of the European Study Group on Cardiovascular Oscillations, and hosted the 1st ESGCO Conference in Cardiff, Wales in 2000. Tudor was a passionate scientist, who managed to combine his enthusiasm for vascular biology with his background in physics, to make key and insightful advances to our knowledge and understanding of the integrated vascular control mechanisms that co-ordinate blood flow in tissue perfusion. He had a particular interest in the endothelium, the monolayer of cells that lines the entire cardiovascular system and which is in prime position to sense a wide variety of modulatory stimuli, both chemical and mechanical. Over the last 20 years Tudor produced a series of research papers in which he used chaos theory to analyse the behaviour of arteries that underpins vasomotion. The research led to the development of mathematical models that were able to predict calcium oscillations in vascular smooth muscle with a view to predicting events in a complete virtual artery. This article will review the field in which he worked, with an obvious emphasis on his contribution.