Spinal cord function monitoring during endovascular treatment of thoracoabdominal aneurysms: implications for staged procedures

AIM

Spinal cord ischemia is a well-known complication in the treatment of thoracoabdominal aneurysms (TAAA). Despite the fact that endovascular treatment of TAAA is less invasive, spinal cord ischemia rate is not reduced if compared to open repair.

METHODS

We report the results of our experience of spinal cord function monitoring by measuring motor evoked potentials (MEP) during endovascular treatment of TAAA type II and III. Depending on the level of the MEPs the decision is made whether to stage the procedure or not. We treated ten patients according to this protocol.

RESULTS

In two patients, MEPs decreased 50% or more and procedures were staged. Both experienced no neurological complications after first and second procedure. No MEPs decrease was seen during the second procedures. One of the other eight patients had a temporary right lower leg pararesis.

CONCLUSION

In conclusion we state that our first experience demonstrates the value of assessing spinal cord function during extensive endovascular TAAA repair with subsequent strategies to prevent paraplegia.

Effect of heparin on neuroprotection against spinal cord ischemia and reperfusion in rats

BACKGROUND

Paraplegia due to ischemia/reperfusion (I/R) injury of the spinal cord is a devastating and undesired complication of thoraco-abdominal aortic surgery. Unidentified clots cause a variety of thromboembolic events and deteriorate the severity of ischemia. We investigated the effect of the degree of anticoagulation on spinal cord I/R injury and whether heparin is protective against I/R injury beside its anticoagulant properties.

MATERIALS AND METHODS

Twenty-eight rats were randomly assigned to four groups (n=7 per group) as G1 (no aortic occlusion and heparin administration), G2 (45 min aortic occlusion; no heparin administration), G3 (45 min aortic occlusion; 400 IU/kg heparin to keep activated clotting time (ACT) level around 200 sec), and G4 (45 min aortic occlusion; 800 IU/kg heparin to keep ACT level around 600 sec). After neurologic evaluation at the 48th hour of reperfusion, lumbar spinal cords were removed for histopathologic evaluation and immunohistochemical staining for HSP70 (heat shock protein 70), interleukin-6 and myeloperoxidase (MPO).

RESULTS

The Motor Deficit Index (MDI) scores were lowest in G1 group (p < 0.05) and the MDI scores of G3 and G4 were significantly lower than G2 group (p < 0.05). The neuronal degeneration in G3 was significantly lower than the other groups, respectively (p = 0.03). Histopathological evaluation showed no significant intergroup differences in terms of the degree of edema and inflammatory response. There was no statistically significant difference found among the groups in terms of HSP70 staining, IL-6 staining or the degree of MPO staining.

CONCLUSIONS

Protection of spinal cord from I/R injury requires a multimodal management. We should not miss out the importance of adequate anticoagulation in thoraco-abdominal surgical procedures. Furthermore, the recently discovered anti-inflammatory property of glycosaminoglycans, including heparin, deserves to be investigated.

Alpha-tocopherol ameliorates oxidative renal insult associated with spinal cord reperfusion injury

Ischemic-reperfusion procedures targeting a specific organ often results in remote multiple organ injuries mediated possibly by heightened oxidative stress levels. As the kidney is one of the most vulnerable organs for ischemic oxidative stress, the aim of the present study was to confirm the occurrence of renal complication secondary to spinal cord ischemic-reperfusion injury (SC-IRI) induced by aortic clamping. The study also investigated the possible prophylactic effect of long-term administration of α-tocopherol (α-TOL) against high level of renal oxidative stress and inflammatory processes induced by SC-IRI. In this study, a total of 60 male Sprague-Dawley rats were randomly divided into five equal groups: C group underwent no surgery; CE group received α-TOL 600 mg/kg intramuscular twice weekly for 6 weeks; S group were subjected to laparotomy without clamping of the aorta; SE group were handled as S group and treated with α-TOL as group CE; SC-IRI group were subjected to laparotomy with clamping of the aorta just above the bifurcation of the aorta for 45 min, then the clamp was released for 48 h for reperfusion. SC-IRIE group was subjected to IRI as in group SC-IRI and was injected with α-TOL in the same dose and route as α-TOL-treated control group. SC-IRI resulted in increases in serum creatinine, blood urea nitrogen, plasma nitrite/nitrate level, serum tumor necrosis factor alpha, renal tissue homogenate level for malondialdehyde, superoxide dismutase and prostaglandin E2. Long-term prophylactic treatment with α-TOL resulted in amelioration of the renal functional disturbances and all measured parameters of oxidative stress and inflammation. Ischemic reperfusion injury of the spinal cord induced some remote renal functional disturbances although some of the observed changes may have resulted from decreased renal blood flow due to the hypotension induced during the procedure. Prophylactic long-term α-TOL administration guards against the renal function disturbances an effect that can be attributed, at least partially, to improvement of the renal pro-oxidant/antioxidant balance and inhibition of the inflammatory processes.

Spinal ventral epidural arteriovenous fistulas of the lumbar spine: angioarchitecture and endovascular treatment

Introduction

Spinal ventral epidural arteriovenous fistulas (EDAVFs) are relatively rare spinal vascular lesions. We investigated the angioarchitecture of spinal ventral EDAVFs and show the results of endovascular treatment.

Methods

We reviewed six consecutive patients (four males and two females; mean age, 67.3 years) with spinal ventral EDAVFs treated at our institutions from May 2011 to October 2012. All patients presented with progressive myelopathy. The findings of angiography, including 3D/2D reformatted images, treatments, and outcomes, were investigated. A literature review focused on the angioarchitecture and treatment of spinal ventral EDAVFs is also presented.

Results

The EDAVFs were located in the ventral epidural space at the L1–L5 levels. All EDAVFs were supplied by the dorsal somatic branches from multiple segmental arteries. The ventral somatic branches and the radiculomeningeal arteries also supplied the AVFs in two patients. The AVFs drained via an epidural venous pouch into the perimedullary vein in four patients and into both the perimedullary vein and paravertebral veins in two patients. Four cases without paravertebral drainage were treated by transarterial embolization with diluted glue, and two cases with perimedullary and paravertebral drainages were treated by transvenous embolization alone or in combination with transarterial embolization. An angiographic cure was obtained in all patients. Clinical symptoms resolved in two patients, markedly improved in three patients, and minimally improved in one patient.

Conclusion

In our limited experience, spinal ventral EDAVFs were primarily fed by somatic branches. EDAVFs can be successfully treated by endovascular techniques selected based on the drainage type of the AVF.

Blood-spinal cord barrier breakdown and pericyte reductions in amyotrophic lateral sclerosis

The blood-brain barrier and blood-spinal cord barrier (BSCB) limit the entry of plasma components and erythrocytes into the central nervous system (CNS). Pericytes play a key role in maintaining blood-CNS barriers. The BSCB is damaged in patients with amyotrophic lateral sclerosis (ALS). Moreover, transgenic ALS rodents and pericyte-deficient mice develop BSCB disruption with erythrocyte extravasation preceding motor neuron dysfunction. Here, we studied whether BSCB disruption with erythrocyte extravasation and pericyte loss are present in human ALS. We show that 11 of 11 cervical cords from ALS patients, but 0 of 5 non-neurodegenerative disorders controls, possess perivascular deposits of erythrocyte-derived hemoglobin and hemosiderin typically 10-50 μm in diameter suggestive of erythrocyte extravasation. Immunostaining for CD235a, a specific marker for erythrocytes, confirmed sporadic erythrocyte extravasation in ALS, but not controls. Quantitative analysis revealed a 3.1-fold increase in perivascular hemoglobin deposits in ALS compared to controls showing hemoglobin confined within the vascular lumen, which correlated with 2.5-fold increase in hemosiderin deposits (r = 0.82, p < 0.01). Spinal cord parenchymal accumulation of plasma-derived immunoglobulin G, fibrin and thrombin was demonstrated in ALS, but not controls. Immunostaining for platelet-derived growth factor receptor-β, a specific marker for CNS pericytes, indicated a 54 % (p < 0.01) reduction in pericyte number in ALS patients compared to controls. Pericyte reduction correlated negatively with the magnitude of BSCB damage as determined by hemoglobin abundance (r = -0.75, p < 0.01). Thus, the BSCB disruption with erythrocyte extravasation and pericyte reductions is present in ALS. Whether similar findings occur in motor cortex and affected brainstem motor nuclei remain to be seen.

[Spinal stroke in the acute myeloblast leucosis]

Data of literature on the frequency of the nervous system lesions in different variants of leucosis are analyzed. A case of a man with petechial skin rash and bruises on the body, gingival hemorrhage and general sickness is described in details. The hematologic tests revealed acute myeloblast leucosis. A lumbar puncture revealed blood in the cerebrospinal fluid and MRI showed an epidural hematoma in lumbar segments 3 and 4. At this level, the hematoma compressed the dural bag and roots of the horse tail with accompanying vessels (the radicular medullar artery and large radicular veins). A paracentetic removal of the hematoma with the decompression of spinal roots was carried out. The blasts in the cerebrospinal fluid and symptoms of the left facial nerve lesion allowed to diagnose neuroleucosis. This case presented the mixed pathogenesis of myeloischemia. The epidural hematoma compressed not only the roots of the horse tail but the accompanying vessels (arteries and veins). The venous outflow obstruction along radicular veins worsened the microcirculation in the cross-sectional area of the spinal cord. Complex polychemotherapy in the combination with neuroprotectors (cortexin, gliatiline), antiaggregants and vitamins is recommended.

Posterior spinal artery syndrome showing marked swelling of the spinal cord: a clinico-pathological study

OBJECTIVE

To describe a rare autopsy case of posterior spinal artery syndrome with marked swelling of the spinal cord, an unusually subacute onset and short clinical course.

METHODS

Case report.

FINDINGS

An 84-year-old Japanese woman presented with bilateral muscle weakness of the lower legs and sensory disturbance 1 week after head contusion. Neurological findings worsened gradually. She developed phrenic nerve paralysis and died of respiratory failure 6 weeks after the onset of neurological symptoms. On pathological examination, the spinal cord was markedly swollen in the cervical and upper thoracic segments. Microscopically, there was loss of myelin sheath in the bilateral posterior columns and neuronal loss of the posterior horns in all of the spinal segments. However, findings were unremarkable in the bilateral anterior columns and bilateral anterior horns in most of the spinal segments. Posterior spinal arteries had no stenosis, occlusion, or thrombosis. We considered that pathogenesis was infarction associated with head injury.

CONCLUSION

To our knowledge, this is the first report of a case of posterior spinal artery syndrome with a markedly swollen spinal cord and poor prognosis.

Pre-evaluated safe human iPSC-derived neural stem cells promote functional recovery after spinal cord injury in common marmoset without tumorigenicity

Murine and human iPSC-NS/PCs (induced pluripotent stem cell-derived neural stem/progenitor cells) promote functional recovery following transplantation into the injured spinal cord in rodents. However, for clinical applicability, it is critical to obtain proof of the concept regarding the efficacy of grafted human iPSC-NS/PCs (hiPSC-NS/PCs) for the repair of spinal cord injury (SCI) in a non-human primate model. This study used a pre-evaluated “safe” hiPSC-NS/PC clone and an adult common marmoset (Callithrix jacchus) model of contusive SCI. SCI was induced at the fifth cervical level (C5), followed by transplantation of hiPSC-NS/PCs at 9 days after injury. Behavioral analyses were performed from the time of the initial injury until 12 weeks after SCI. Grafted hiPSC-NS/PCs survived and differentiated into all three neural lineages. Furthermore, transplantation of hiPSC-NS/PCs enhanced axonal sparing/regrowth and angiogenesis, and prevented the demyelination after SCI compared with that in vehicle control animals. Notably, no tumor formation occurred for at least 12 weeks after transplantation. Quantitative RT-PCR showed that mRNA expression levels of human neurotrophic factors were significantly higher in cultured hiPSC-NS/PCs than in human dermal fibroblasts (hDFs). Finally, behavioral tests showed that hiPSC-NS/PCs promoted functional recovery after SCI in the common marmoset. Taken together, these results indicate that pre-evaluated safe hiPSC-NS/PCs are a potential source of cells for the treatment of SCI in the clinic.

Spinal dural fistulas without swelling and edema of the cord as incidental findings

SUMMARY

SDAVFs cause hypertension and hence outflow obstruction in the perimedullary venous system resulting in swelling and edema of the cord followed by dysfunction. Clinical presentation is usually with gradual progressive paraparesis, numbness, and sphincter problems. MR imaging typically demonstrates the dilated perimedullary veins and the swelling and edema of the cord. During the past few years, we incidentally found an SDAVF on MR imaging with dilated perimedullary veins but without swelling and edema of the cord in 5 patients with unrelated presenting clinical symptoms. Spinal angiography confirmed the presence of an SDAVF in all 5 patients. Although the indication was considered questionable, eventually all 5 fistulas were endovascularly or surgically treated, resulting in normalization of the MR images.

Spinal arteriovenous malformation presenting with prolapsed intervertebral disc: a diagnostic dilemma

The availability of multiple investigating modalities should be utilized to arrive at the correct diagnosis of the spinal arteriovenous malformation (AVM). We hereby report the case of a 21-year-old, obese female, who presented with paraplegia and impaired bowel control two years after an episode of the fall. The Magnetic Resonance Imaging (MRI) of her spine not only revealed disc prolapse at T11-T12, but also tortuous dilated spinal veins and cord oedema. A diagnosis of a spinal arterio-venous fistula was confirmed after a spinal angiogram. The dilemma of treating the right pathology for the clinical signs and symptoms are being discussed.

[Anesthetic considerations for endovascular aortic repair (EVAR)]

The endovascular repair of thoracic aortic aneurysm and abdominal aortic aneurysm has become a promising alternative for open surgical graft replacement. The benefits of EVAR include less invasiveness, no need for cardiopulmonary bypass or differential lung ventilation, less blood loss, shorter hospital stay and reduced perioperative morbidity and mortality. Therefore EVAR is especially desirable for patients with impaired cardiopulmonary function or multiple comorbidities and they are at high risk of complications following general anesthesia such as stroke, myocardial infarction, acute renal insufficiency, infection and failure to wean from ventilator. Thoracic endovascular aortic repair (TEVAR) also carries the risk of paraplegia induced by spinal cord ischemia. Previous abdominal aortic aneurysm repair, prolonged hypotension, severe atherosclerosis of the thoracic aorta, injury to the external iliac artery, and more extensive coverage of the thoracic aorta by the graft are reported to be the risk factors for paraplegia after TEVAR. In such cases, strategies to protect the spinal cord from ischemia including lumbar cerebrospinal fluid drainage should be taken.

Cerebrospinal fluid drainage for thoracic and thoracoabdominal aortic aneurysm surgery

BACKGROUND

During aortic aneurysm surgery, cross-clamping can lead to inadequate blood supply to the spinal cord resulting in neurological deficit. Cerebrospinal fluid drainage (CSFD) may increase the perfusion pressure to the spinal cord and hence reduce the risk of ischaemic spinal cord injury.

OBJECTIVES

To determine the effect of CSFD during thoracic and thoracoabdominal aortic aneurysm (TAAA) surgery on the risk of developing spinal cord injury.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched May 31 2012) and CENTRAL (2012, Issue 5) for publications describing randomised controlled trials of cerebrospinal fluid drainage for thoracic and thoracoabdominal aortic aneurysm surgery. Reference lists of relevant articles were checked.

SELECTION CRITERIA

Randomised trials involving CSFD during thoracic and TAAA surgery.

DATA COLLECTION AND ANALYSIS

Both authors assessed the quality of trials independently. SNK extracted data and GS verified the data.

MAIN RESULTS

Three trials with a total of 287 participants operated on for Type I or II TAAA were included.In the first trial of 98 participants, neurological deficits in the lower extremities occurred in 14 (30%) of CSFD group and 17 (33%) controls. The deficit was observed within 24 hours of the operation in 21 (68%), and from three to 22 days in 10 (32%) participants. CSFD did not have a significant benefit in preventing ischaemic injury to the spinal cord.The second trial of 33 participants used a combination of CSFD and intrathecal papaverine. It showed a statistically significant reduction in the rate of postoperative neurological deficit (P = 0.039), compared to controls. Analysis was undertaken after only one third of the estimated sample size had entered the trial.In the third trial TAAA repair was performed on 145 participants. CSFD was initiated during the operation and continued for 48 hours after surgery. Paraplegia or paraparesis occurred in 9 of 74 participants (12.2%) in the control group versus 2 of 82 participants (2.7%) receiving CSFD (P = 0.03). Overall, CSFD resulted in an 80% reduction in the relative risk of postoperative deficits. Meta-analysis showed an odds ratio (OR) of 0.48 (95 % confidence interval (CI) 0.25 to 0.92). For CSFD-only trials, OR was 0.57 (95% CI 0.28 to 1.17) and for intention-to-treat analysis in CSFD-only studies, the OR remained unchanged.

AUTHORS' CONCLUSIONS

There are limited data supporting the role of CSFD in thoracic and thoracoabdominal aneurysm surgery for prevention of neurological injury. Further clinical and experimental studies are indicated.

[Safty action of heat shock protein 27 in reperfusion after spinal marrow ischemia]

Heat shock protein 27 belongs to the heat shock protein family in the small molecular weight family. This review collected a number of literature to analyze the expression meaning and mechanism of HSP27,expounded HSP27 with inhibition of NO production, maintenance of cell protein stability and accelerated cell damage repair function. At the same time, HSP27 also has a resistance to apoptosis, protecting mitochondria, inhibiting activation of nuclear factor and other related functions. The heat shock protein 27 has protection in spinal cord ischemia-reperfusion.

Exogenous schwann cells migrate, remyelinate and promote clinical recovery in experimental auto-immune encephalomyelitis

Schwann cell (SC) transplantation is currently being discussed as a strategy that may promote functional recovery in patients with multiple sclerosis (MS) and other inflammatory demyelinating diseases of the central nervous system (CNS). However this assumes they will not only survive but also remyelinate demyelinated axons in the chronically inflamed CNS. To address this question we investigated the fate of transplanted SCs in myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) in the Dark Agouti rat; an animal model that reproduces the complex inflammatory demyelinating immunopathology of MS. We now report that SCs expressing green fluorescent protein (GFP-SCs) allografted after disease onset not only survive but also migrate to remyelinate lesions in the inflamed CNS. GFP-SCs were detected more frequently in the parenchyma after direct injection into the spinal cord, than via intra-thecal delivery into the cerebrospinal fluid. In both cases the transplanted cells intermingled with astrocytes in demyelinated lesions, aligned with axons and by twenty one days post transplantation had formed Pzero protein immunoreactive internodes. Strikingly, GFP-SCs transplantation was associated with marked decrease in clinical disease severity in terms of mortality; all GFP-SCs transplanted animals survived whilst 80% of controls died within 40 days of disease.

[The Multi-detector-row CT angiography for diagnosis of spinal dural arteriovenous fistula]

PURPOSE

Multi-detector-row CT angiography (MDCTA) is useful for diagnosis of spinal arteriovenous (AV) shunt. So we reported the role and pitfall of MDCTA based on our experience.

SUBJECTS

From January 2007 to September 2011, 57 cases used MDCTA in our institution. We investigated 22 case of spinal dural AVF and 5 cases of epidural AVF.

METHODS

All cases were performed by Toshiba Aquilion 64. FOV was the whole spine, curved planar reconstruction along the spinal canal, sagittal and axial view obtained by multi-planar reconstruction.

RESULTS

MDCTA detected dilated the perimedullary vein in all cases and identified the level of segmental artery matching the result of DSA in 16 cases of spinal dural AVF (73%) and 1 cases of epidural AVF (20%).

CONCLUSION

MDCTA is useful for screening, and identifying the shunt point, but care needs to be taken concerning the particular pitfall of MDCTA.

[Spinal vascular malformations]

Spinal vascular malformations are a group of rare diseases with different clinical presentations ranging from incidental asymptomatic findings to progressive tetraplegia. This article provides an overview about imaging features as well as clinical and therapeutic aspects of spinal arteriovenous malformations, cavernomas and capillary telangiectasia.

[Age-related changes in the nervous apparatus of the blood vessels in the brain and spinal cord]

This work was designed to study changes in the nervous apparatus of the blood vessels in the brain and spinal cord with a view to developing methods for the determination of the biological age in man. Pial and intramedullary vascular systems of the brain and spinal cord were examined in different periods of postnatal ontogenesis (between the age of 1 and 90 years) using histological, fluorescent-histochemical, and immunohistochemical methods as well as by ink injections into the blood vessels, scanning and transmission electron microscopy. The data obtained on the age-related rearrangement of the nervous apparatus of the arterial vessels in the brain and spinal cord have not only theoretical significance but can also be used for the solution of practical problems encountered in the practical work of forensic medical experts.

Endovascular embolization for symptomatic perimedullary AVF and intramedullary AVM: a series and a literature review

INTRODUCTION

Perimedullary arteriovenous fistula (AVF) has shunt on the spinal cord surface and it can be treated with surgery, or endovascular embolization. Intramedullary arteriovenous malformation (AVM) has its nidus in the cord and is difficult to treat either by surgery or endovascular technique. We report our experience with endovascular embolization in the treatment of perimedullary AVF and intramedullary AVM.

METHODS

Four consecutive cases of spinal perimedullary AVF and six intramedullary AVM were retrospectively reviewed. These cases were evaluated and treated at Beijing Tiantan Hospital, China, over a 2-year period. A review of previously reported cases was also performed.

RESULTS

There was no significant difference in the presentations (P = 0.348), level of lesions (P = 0.350), arterial suppliers (P = 0.801), and associated vascular anomalies between perimedullary AVF and intramedullary AVM, except for age (P = 0.014) and treatment modalities (P = 0.003). The patients with perimedullary AVFs were younger in our cases; the age at onset of symptoms averaged 25.8 years compared to 31.7 years for intramedullary AVMs. There was a significant male predominance for both lesions, and a significantly higher incidence of subarachnoid hemorrhage than in spinal dural AVFs. Regarding treatment, endovascular coil embolization is frequently used in perimedullary AVF and liquid embolic agent is an effective therapeutic choice in intramedullary AVM.

CONCLUSION

Perimedullary AVF and intramedullary AVM are dissimilar with dural AVF in clinical characteristics. Our experience suggests that the endovascular treatment of spine perimedullary AVFs and intramedullary AVMs is feasible and effective. Endovascular treatment for intramedullary AVMs is still challenging, the main problem is acute ischemia injury of the spinal cord.

[Resveratrol: a neuroprotective polyphenol in the Mediterranean diet]

INTRODUCTION

Resveratrol is a polyphenol present in grapes, some nuts and dried fruits, and red wine. A number of beneficial properties have been attributed to this compound. Its potential neuroprotective effects are the subject of much research today.

AIM

To review the effects of resveratrol, and more particularly those related to its capacity to offer protection against the neurodegeneration associated with several pathologies and traumatic injuries in the central nervous system.

DEVELOPMENT

It has been suggested that the daily consumption of red wine, and therefore of resveratrol, could account for the so-called 'French paradox', according to which the population in the south of France, despite eating a diet that is relatively high in saturated fats, presents a low risk of heart disease. From this first evidence of the cardioprotective properties of resveratrol, its study has been extended and equally attractive biopharmacological effects have now been found in many different fields. Thus, neuroprotective effects have been found in models of neurodegeneration (Alzheimer's, Parkinson's or Huntington's disease, or diverse neuropathies), of ischaemia and of brain and spinal cord injury, but further clinical data are still needed in this regard.

CONCLUSIONS

Although few studies have been conducted in humans, recent findings in experimental models of neurological pathology are encouraging and open up the doors to future clinical studies that will allow the therapeutic value of resveratrol to be determined.

Distal aortic perfusion during thoracoabdominal aneurysm repair for prevention of paraplegia

BACKGROUND

During thoracoabdominal aortic aneurysm (TAAA) surgery, decreased spinal cord perfusion can result in neurological deficits such as paraplegia and paraparesis. Distal aortic perfusion, alone or in combination with other adjuncts, may counter the decrease in spinal cord perfusion and hence reduce the risk of spinal cord injury.

OBJECTIVES

To determine the effectiveness of distal aortic perfusion with or without other adjuncts against other adjuncts without use of distal perfusion during TAAA surgery in reducing the risk of developing paraplegia and paraparesis.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Specialised Register (last searched 5 January 2012) and CENTRAL (Issue 4, 2011) were searched for publications describing randomised controlled trials of distal aortic perfusion during thoracoabdominal aortic aneurysm surgery. Reference lists of relevant studies were checked.

SELECTION CRITERIA

Randomised or quasi-randomised controlled clinical trials of distal aortic perfusion during TAAA repair.

DATA COLLECTION AND ANALYSIS

Studies identified for potential inclusion were independently assessed for inclusion by at least two authors, with excluded trials arbitrated by the third author.

MAIN RESULTS

There were no randomised controlled trials identified.

AUTHORS' CONCLUSIONS

Currently, there are no randomised controlled trials to support the role of distal aortic perfusion in TAAA surgery for prevention of neurological injury. However, randomised controlled trials are not always feasible based on ethical grounds. Observational studies suggest that distal aortic perfusion alone or in combination with other adjuncts, that is cerebrospinal fluid (CSF) drainage, reduces the rate of neurologic deficit across all types of TAAA; in particular making a striking difference in the rate of neurologic deficit following type II TAAA repair. In the absence of randomised controlled trials, we recommend a standardised approach to reporting through registry studies to strengthen the evidence base for distal aortic perfusion.

Complex arteriovenous fistulas at C1 causing hematomyelia through aneurysmal rupture of a feeder from the anterior spinal artery

A 64-year-old woman presented with left occipital headache and right dissociated sensory loss due to hematomyelia on the left ventral side of C1 caused by rupture of an aneurysm on one of the feeders extending from the anterior spinal artery to complex epidural or dural and intradural arteriovenous fistulas (AVFs). Branches from the left occipital and ascending pharyngeal arteries and those from the left C2 radicular, left posterior spinal and anterior spinal arteries formed these multiple shunts, linking with a common venous drain flowing into the right petrosal vein. Surgical interception of all the shunts was achieved, making it unnecessary to directly treat the aneurysm in the spinal cord. The feeders, aneurysm and AVFs were not visualized on postoperative angiography, and the patient returned to a normal working life.

Early and progressive impairment of spinal blood flow-glucose metabolism coupling in motor neuron degeneration of ALS model mice

The exact mechanism of selective motor neuron death in amyotrophic lateral sclerosis (ALS) remains still unclear. In the present study, we performed in vivo capillary imaging, directly measured spinal blood flow (SBF) and glucose metabolism, and analyzed whether if a possible flow-metabolism coupling is disturbed in motor neuron degeneration of ALS model mice. In vivo capillary imaging showed progressive decrease of capillary diameter, capillary density, and red blood cell speed during the disease course. Spinal blood flow was progressively decreased in the anterior gray matter (GM) from presymptomatic stage to 0.80-fold of wild-type (WT) mice, 0.61 at early-symptomatic, and 0.49 at end stage of the disease. Local spinal glucose utilization (LSGU) was transiently increased to 1.19-fold in anterior GM at presymptomatic stage, which in turn progressively decreased to 0.84 and 0.60 at early-symptomatic and end stage of the disease. The LSGU/SBF ratio representing flow-metabolism uncoupling (FMU) preceded the sequential pathological changes in the spinal cord of ALS mice and was preferentially found in the affected region of ALS. The present study suggests that this early and progressive FMU could profoundly involve in the whole disease process as a vascular factor of ALS pathology, and could also be a potential target for therapeutic intervention of ALS.

Spinal cord syndromes

Spinal cord infarction is much rarer than cerebral stroke, but its early recognition is important as it may signify serious aortic conditions. The most frequent type is anterior spinal artery syndrome, presenting with bilateral weakness (usually paraparesis), impairment of spinothalamic sensation and preservation of deep sensation. Depending on its level, it may present with respiratory dysfunction. More rarely, posterior infarcts sparing spinothalamic sensation but involving lemniscal sensation may be encountered. Unilateral, central or transverse infarction may also be seen probably on account of different mechanisms. Other rarer forms of spinal ischemia also include spinal TIAs, venous infarction, fibrocartilaginous embolism and decompression sickness.

A case of extrinsic chronic cerebrospinal venous insufficiency in a patient with multiple sclerosis

We aim to present a very rare case of chronic cerebrospinal venous insufficiency due to both brachiocephalic vein obstruction by aberrant right subclavian artery and internal jugular vein distal compression by first cervical vertebra transverse process, demonstrated by multislice computerized tomography in a patient with multiple sclerosis.

Panax notoginsenoside produces neuroprotective effects in rat model of acute spinal cord ischemia-reperfusion injury

ETHNOPHARMACOLOGICAL RELEVANCE

Acute spinal cord ischemia-reperfusion injury (SCII) is associated with pathological changes, including inflammation, edema, and neuronal apoptosis. Panax notoginsenoside (PNS), an important traditional Chinese medicine, has shown a variety of beneficial effects, including homeostasis maintenance, anti-myocardial ischemia activities, and neuroprotective functions. However, whether it can produce neuroprotective effects in SCII and the underlying mechanisms remain largely elusive.

AIM OF THE STUDY

In the present study, we investigated the effects of PNS on neurological and histopathological changes after SCII as well as the underlying mechanisms.

MATERIALS AND METHODS

Sixty-four adult rats were randomly assigned into one of the four groups: the sham group, the ischemic group, the PNS group, and the Methylprednisolone group. A rat model of SCII was adopted from a commonly used protocol that was initially proposed by Zivin. Neurological function was evaluated with the Basso, Beattie and Bresnahan (BBB) locomotor rating scale. Histopathological changes were examined with hematoxylin and eosin staining as well as Nissl staining. Immunohistochemistry and Western blot were conducted to compare the changes in tumor necrosis factor-α, interleukin-1β, interleukin-10, aquaporin-4 (AQP-4), member 6 of the TNF receptor superfamily (Fas), and Fas ligand (FasL) in the spinal cord. Finally, neuronal apoptosis was measured by electron microscopy.

RESULTS

The BBB scores of the PNS-treated injured animals were significantly increased. The gross histopathological examination showed restored neuronal morphology and increased number of neurons after the PNS treatment. The PNS treatment decreased SCII-induced up-regulation of cytokine levels. In addition, PNS suppressed the increased expression of AQP-4 after SCII, suggesting an anti-edema effect. Finally, PNS treatment inhibited injury-induced apoptosis and reduced the expression levels of apoptosis-related proteins, Fas and FasL, confirming its anti-apoptosis effects against SCII.

CONCLUSION

The current findings suggest that PNS produces robust neuroprotective effects in spinal cord ischemia-reperfusion injury, and this role may be mediated by its anti-inflammation, anti-edema, and anti-apoptosis actions.

An unique case of thoracic endovascular aortic repair (TEVAR) graft infection with Streptococcus viridans

The incidence of infection following TEVAR is low. To the best of our knowledge, this is the first case report of post thoracic endovascular aortic repair (TEVAR) with Streptococcus viridans graft infection. A 54-year-old male underwent TEVAR for dissecting thoracic aneurysm with spinal ischaemia. He had an eventful recovery with prolonged period of stay in intensive care unit. Three months later, he presented with persistent chest discomfort and fever. Computed tomography (CT) of the thorax revealed evidence of graft infection and the blood culture grew Streptococcus viridans. The rarity of TEVAR graft infection due to Streptococcus viridans and its management are being discussed.

[Intravascular large B-cell lymphoma with low signal intensity lesions on T2 weighted spinal magnetic resonance image that were suspected to be hemorrhages]

A 79-year-old female had a spinal lesion that was definitely diagnosed as intravascular large B-cell lymphoma on the basis of skin biopsy findings, and she was treated by rituximab-containing chemotherapy. The spinal lesion showed high and low signal intensities on T₂ weighted magnetic resonance imaging (MRI) scans, those low signal intensity lesions were suspected to be hemorrhages. The hemorrhages were thought to have been caused by interaction between atypical lymphoma cells and the endothelial cells of spinal blood vessels, by hemorrhagic infarction or by rupture of the capillary endothelium due to interaction between rituximab and lymphoma cells. Intravascular large B-cell lymphoma cases rarely show low signal intensity on spinal T₂ weighted MRI scans.

[Forensic medical characteristic of the neurovascular apparatus in the case of spinal cord injury]

This paper is devoted to the analysis of the results of the author's investigations concerning spinal cord injuries. The voluminous material obtained with the use of up-to-date research methods (histological, histochemical, and biochemical) includes basic data on the mechanisms of regulation of blood circulation under normal conditions and in the case of a mechanical injury. It is shown that pathological morphological changes in the affected areas of the spinal cord as well as activities of transport enzymes in the capillaries and the reactive processes in the monoaminoergic nervous apparatus of he arteries may be used as the objective criteria for the determination of the time of the injury. The results of these studies find application in the practical diagnostic work for the estimation of the time of the spinal cord injury.

[First experience with monitoring somatosensory and motor evoked potential during operations on the thoracic and thoracoabdominal portions of the aorta]

Specialists in Russia have recently gained vast experience in operations on the thoracic and thoracoabdominal portion of the aorta; however, studying evoked potentials for preventing lesions of the spinal marrow have not been studied in any clinic. The authors report herein their first experience in Russia in studying the function of the marrow during operations on the aorta followed by detailed description of the technique of registering evoked potentials. From June 2010 to January 2011, specialists of the Arterial Pathology Department of the A. N. Bakulev Scientific Centre for Cardiovascular Surgery under the Russian Academy of Medical Sciences carried out a neurophysiological study in a total of 19 patients during operations for thoracic and thoracoabdominal aortic aneurysms. The somatosensory and motor evoked potentials were studied using an 8-channel neuroenhancer Keypoint (Dantec, Denmark). The hospital mortality rate in the examined group amounted to 5.2% (1/19). Spinal stroke developed in 2 patients, i.e. in 10.5% (2/19). The alterations in the somatosensory and motor evoked potentials were subdivided into groups according to the morphological classification of Crawford-Cunningham. A further two patients were found to have during operation type III changes in the evoked potentials, with both having developed postoperative spinal stroke. Thus, the method of intraoperative monitoring of evoked potentials has high sensitivity and specificity and can be included into the protocol of operations on the thoracic and abdominothoracic portion of the aorta. During monitoring of evoked potentials it is necessary to maintain a permanent level of anaesthesia and myorelaxation with obligatory participation of the neurophysiologist in the operation.

Screening for chronic cerebrospinal venous insufficiency (CCSVI) using ultrasound--recommendations for a protocol

Chronic cerebrospinal venous insufficiency (CCSVI) is a syndrome characterized by stenoses or obstructions of the internal jugular and/or azygos veins with disturbed flow and formation of collateral venous channels. Studies using ultrasound in patients with multiple sclerosis (MS) have demonstrated a high prevalence of CCSVI (mean 70%; range 0-100%; N.=1496), whereas, in normal controls and patients without MS the prevalence was much lower (mean 10%; range 0-36%; N.=635). Ultrasound uses a combination of physiological measurements as well as anatomical imaging and has been used for the detection of CCSVI by different centers with variable results. A high prevalence ranging from 62% to 100% of obstructive lesions has been found by some teams in patients with MS compared with a lower prevalence of 0-25% in controls. However, absence of such lesions or a lower prevalence (16-52%) has been reported by others. This variability could be the result of differences in technique, training, experience or criteria used. The current lack of a methodology shared among experts is a confounding element in epidemiologic studies, and does not permit further Bayesan or other kind of analysis. In order to ensure a high reproducibility of Duplex scanning with comparable accuracy between centers, a detailed protocol with standard methodology and criteria is proposed. This is also necessary for training. It has been shown that inter-rater variability increases post-training (from k=0.47 to k=0.80), while within-rater reproducibility in trained operators was k=0.75. Finally, the consensus document proposes a reporting standard of Duplex measurements, and future research to answer areas of uncertainty.

Dural arteriovenous fistula with spinal perimedullary venous drainage

The purpose of this study was to investigate the characteristics of six patients with dural arteriovenous fistula (DAVF) with drainage directly into the perimedullary venous system. In five patients with subarachnoid hemorrhage (SAH), cerebral angiography revealed a DAVF with spinal venous drainage located at the petrosal sinus in one, at the tentorium in one, and at the craniocervical junction in four. In the patient with myelopathy, angiographic exploration began with a spinal angiogram. Bilateral vertebral angiography initially failed to demonstrate the fistula, and a tentorial DAVF was established with carotid artery angiography. Patients had no myelopathy when the venous drainage was limited to the cervical cord; myelopathy was present when the venous drainage descended toward the conus medullaris. Diagnosis of a DAVF presenting with myelopathy is more challenging than of those presenting with SAH.

Chronic cerebrospinal venous insufficiency in multiple sclerosis: clinical correlates from a multicentre study

BACKGROUND

Chronic cerebrospinal venous insufficiency (CCSVI) has recently been reported to be associated with multiple sclerosis (MS). However, its actual prevalence, possible association with specific MS phenotypes, and potential pathophysiological role are debated.

METHOD

We analysed the clinical data of 710 MS patients attending six centres (five Italian and one Canadian). All were submitted to venous Doppler sonography and diagnosed as having or not having CCSVI according to the criteria of Zamboni et al.

RESULTS

Overall, CCSVI was diagnosed in 86% of the patients, but the frequency varied greatly between the centres. Even greater differences were found when considering singly the five diagnostic criteria proposed by Zamboni et al. Despite these differences, significant associations with clinical data were found, the most striking being age at disease onset (about five years greater in CCSVI-positive patients) and clinical severity (mean EDSS score about one point higher in CCSVI-positive patients). Patients with progressive MS were more likely to have CCSVI than those with relapsing-remitting MS.

CONCLUSION

The methods for diagnosing CCSVI need to be refined, as the between-centre differences, particularly in single criteria, were excessively high. Despite these discrepancies, the strong associations between CCSVI and MS phenotype suggest that the presence of CCSVI may favour a later development of MS in patients with a lower susceptibility to autoimmune diseases and may increase its severity.

The clinical features and surgical outcomes of patients with intramedullary spinal cord cavernous malformations

BACKGROUND

Cavernous malformations (CMs) are not uncommon, but most of them are found to be located intracranially. Intramedullary CMs are rare, accounting for only 3-5% of identified total central nervous system lesions. The natural history of intramedullary CMs and their clinical features, including the risk of hemorrhage from a large series, still remains unclear and needs to be elucidated. We review our experience with surgically treated patients with intramedullary CMs and discuss the clinical features and surgical outcomes.

METHODS

Between March 2004 and March 2010, a total of 21 patients with intramedullary spinal cord CMs were surgically treated in a single institution. Data from 21 patients were retrospectively analyzed.

RESULTS

There were 13 females and 8 males ranging in age from 10 to 70 years (mean age 39.3 years). All patients harbored single symptomatic CM of the nervous system, and multiple lesions were not found. The annual retrospective hemorrhage rate was 2.18% per patient/year. All but one CM were completely resected, and the average follow-up period was 22.1 months (1-73 months). Ten of the 21 patients experienced an improvement in neurological state, 9 patients remained unchanged, and 2 patients experienced worsening of their conditions.

CONCLUSIONS

Symptomatic intramedullary CMs should be surgically removed to avoid further neurological deterioration. Though there are some limitations due to the retrospective nature of this study and its small number of patients, the prognosis was found to be related to the preoperative neurological state and to the type of symptom presentation.

Advanced MRI in multiple sclerosis: current status and future challenges

MRI has rapidly become a leading research tool in the study of multiple sclerosis (MS). Conventional imaging is useful in diagnosis and management of the inflammatory stages of MS but has limitations in describing the degree of tissue injury and cause of progressive disability seen in later stages. Advanced MRI techniques hold promise for filling this void. These imaging tools hold great promise to increase understanding of MS pathogenesis and provide greater insight into the efficacy of new MS therapies.

The optimal therapeutic timing and mechanism of puerarin treatment of spinal cord ischemia-reperfusion injury in rats

AIM OF THE STUDY

The purpose of this study was to explore the optimal therapeutic timing and mechanism of puerarin treatment of spinal cord ischemia-reperfusion injury.

MATERIALS AND METHODS

The spinal ischemia-reperfusion injury was conducted in male Sprague-Dawley rats, and 50mg/kg of puerarin was injected intraperitoneally at 1, 2, 4 and 6h after the injury. Motor function was measured 48 h after reperfusion started. Thioredoxin expression and apoptosis indices were determined.

RESULTS

Improvement of motor function at 1, 2, and 4h was demonstrated in the animals with puerarin treatment. Ischemia-reperfusion injury resulted in a decrease in the expression of thioredoxin, while puerarin administration elevated the expression of thioredoxin-1/thioredoxin-2 mRNA. Apoptosis indices were significantly reduced by puerarin administration.

CONCLUSIONS

We conclude that administration of puerarin within 4h of spinal ischemia-reperfusion injury reduces ischemic reperfusion damage, and that the neuroprotective effect of puerarin involves an increase in the transcription of thioredoxin and a reduction of apoptosis.

[Conus perimedullary arteriovenous fistula with multiple shunt points including the cauda equina: a case report]

Perimedullary arteriovenous fistula (AVF) is usually located on the surface of the spinal cord and is fed by the anterior spinal artery and/or the posterior spinal artery. We report a rare case of Conus perimedullary AVF with multiple shunt points including the cauda equina. A 68-year-old man presented with leg pain when walking long distances. Magnetic resonance imaging at the thoracic and lumbar level revealed multiple signal voids with marked cord signal change. Angiography showed the perimedullary AVF fed by the anterior spinal artery from the right T9 intercostal artery at the level of the conus medullaris and the fistula fed by the left lateral sacral artery from the left internal iliac artery at the level of the cauda equina. In the first surgery, we performed surgical interruption of feeding arteries from the filum terminale and coagulated AV shunt of the conus medullaris. However residual perimedullary AVF was found at the conus medullaris in the postoperative angiography. Secondary surgery was carried out to treat residual AVF. Follow-up angiography showed complete disappearance of all AVFs. Postoperatively, the patient`s symptoms were improved. Because the Conus perimedullary AVF has the characteristics of multiple feeding arteies, multiple shunt points, and complex venous drainage, it must be kept in mind that other fistula could exist in the cauda equina or filum terminale.

Chronic cerebrospinal vascular insufficiency is not associated with HLA DRB1*1501 status in multiple sclerosis patients

BACKGROUND

Chronic cerebrospinal venous insufficiency (CCSVI) was described as a vascular condition characterized by anomalies of veins outside the skull was reported to be associated with multiple sclerosis (MS). The objective was to assess the associations between HLA DRB1*1501 status and the occurrence of CCSVI in MS patients.

METHODOLOGY/PRINCIPAL FINDINGS

This study included 423 of 499 subjects enrolled in the Combined Transcranial and Extracranial Venous Doppler Evaluation (CTEVD) study. The HLA DRB1*1501 status was obtained in 268 MS patients and 155 controls by genotyping rs3135005, a SNP associated with DRB1*1501 status. All subjects underwent a clinical examination and Doppler scan of the head and neck. The frequency of CCSVI was higher (OR = 4.52, p<0.001) in the MS group 56.0% vs. 21.9% in the controls group and also higher in the progressive MS group 69.8% vs. 49.5% in the non-progressive MS group. The 51.9% frequency of HLA DRB1*1501 positivity (HLA(+)) in MS was higher compared (OR = 2.33, p<0.001) to 31.6% to controls. The HLA(+) frequency in the non-progressive (51.6%) and progressive MS groups (52.3%) was similar. The frequency of HLA(+) CCSVI(+) was 40.7% in progressive MS, 27.5% in non-progressive MS and 8.4% in controls. The presence of CCSVI was independent of HLA DRB1*1501 status in MS patients.

CONCLUSIONS/SIGNIFICANCE

The lack of strong associations of CCSVI with HLA DRB1*1501 suggests that the role of the underlying associations of CCSVI in MS should be interpreted with caution. Further longitudinal studies should determine whether interactions between these factors can contribute to disease progression in MS.