Circulation of the spinal cord: an important consideration for thoracic surgeons

MORPHOLOGICAL JUSTIFICATION OF THE SIGNIFICANCE OF LUMBAR ARTERIES IN THE PREVENTION OF SPINAL CORD ISCHEMIA IN ATHEROSCLEROTIC LESIONS OF ABDOMINAL AORTA

OBJECTIVE

The aim: To investigate atherosclerosis of the abdominal part of the aorta and atherosclerosis of the lumbar arteries, aimed at improving surgical tactics during reconstructive interventions on the abdominal part of the aorta in patients with multifocal atherosclerosis.

PATIENTS AND METHODS

Materials and methods: 20 autopsies were performed. The macro preparation consisted of the part of the abdominal aorta 1х1 sm taken along with a separated lumbar artery for 1-1,5 sm. Histological cuts were coloured with hematoxylin and eosin. The histochemical research was conducted in order to establish changes in all layers of blood vessels. The immunohistochemical research was carried out along with generally accepted histological methods in 10 cases to determine the morphological vessel wall functional state, connective tissue and smooth muscle components.

RESULTS

Results: In all cases there were morphological signs of aortic atherosclerosis with different degrees of damage to the lumen. In none of the analyzed cases did we establish pathomorphological signs of atherosclerosis of the lumbar artery distal to the mouth. In the walls of the lumbar arteries, we noted the preservation of the layered structure, the integrity of the endothelial cells, the normal arrangement of smooth muscle cells.

CONCLUSION

Conclusions: It was established that there cannot be the atherosclerotic occlusion of the lumbar artery, since there are no signs of atheromatous lesions in its walls, the structure of all layers is preserved, the endothelial damage is absent, the location and structure of the lining cells is normal.

Complications of Chest Wall Resection in Conjunction with Pulmonary Resection

Techniques for chest wall resection and reconstruction have evolved over the years. Chest wall resection in conjunction with pulmonary resection has several complications, including pulmonary and infectious. Risk factors for complications are related to the size of the defect, number of ribs resected, and the addition of a pulmonary resection. Material used for reconstruction does not impact the overall complication rate.

Spinal navigation applied to the anterior approach for the resection of thoracic disc herniation: patient series

BACKGROUND

Thoracic disc herniation (TDH) represents a challenge for spine surgeons. The goal of this study is to report the surgical technique and clinical results concerning the application of navigation to anterior transthoracic approaches.

OBSERVATIONS

Between 2017 and 2019, 8 patients with TDH were operated in the lateral decubitus by means of mini-open thoracotomy. An adapted patient referent frame was secured to the iliac wing. The high-speed drill was also navigated. Intraoperative three-dimensional scans were used for level identification, optimized drilling trajectory, and assessment of complete resection. At 12 months follow up, all patients were ambulatory. Seven out of 8 patients (87%) experienced a postoperative neurological improvement. We observed 2 postoperative complications: 1 case of pleural effusion and 1 case of abdominal wall weakness.

LESSONS

In order to increase the safety of anterior transthoracic discectomy, the authors applied the concepts of spinal navigation to the thoracotomy setting. The advantages of this technique include decrease in wrong-level procedure, continuous matching of intraoperative and navigation anatomical findings, better exposure of the TDH, optimized vertebral body drilling, and minimized risk of neurological damage. In conclusion, the authors consider spinal navigation as an important resource for the surgical treatment of patients with TDH.

Unilateral Nerve Root Ligation for Multilevel Vertebral Column Resection After Fixed Post-infectious Deformity

Kyphotic deformity is a well-recognized complication of thoracic vertebral osteomyelitis, often requiring multi-level vertebral column resection for mobilization of the spine and reduction of the deformity. We present a case of severe post-infectious kyphosis treated with multi-level vertebral column resection via a unilateral approach. We obtained excellent decompression and deformity correction without neurologic decline. We review relevant literature regarding spinal cord blood supply and known potential complication of nerve root ligations.

Point-of-Care Thromboelastography for Intrathecal Drain Management in Patients With Coagulopathy and Thoracic Aorta Surgery: A Case Report

Spinal drain placement to prevent spinal cord ischemia during thoracic aorta surgery is a necessary yet complex undertaking in patients with coagulopathies. Thromboelastography (TEG) can be used as a point-of-care management tool to monitor coagulation status before drain placement and removal. We present 2 cases: a case of a patient with factor VII deficiency and a case of a patient with thrombocytopenia for whom TEG was an important procedural adjunct during coagulopathy reversal. TEG parameters are also discussed to encourage more frequent TEG use as an adjunct during these complex cases.

Analysis of spinal cord blood supply combining vascular corrosion casting and fluorescence microsphere technique: A feasibility study in an aortic surgical large animal model

INTRODUCTION

Spinal cord ischemia after cardiovascular interventions continues to be a devastating problem in modern surgery. The role of intraspinal vascular networks and anterior radiculomedullary arteries (ARMA) in preventing spinal cord ischemia is poorly understood.

MATERIALS AND METHODS

Landrace pigs (n = 30, 35.1 ± 3.9 kg) underwent a lateral thoracotomy. Fluorescent microspheres were injected into the left atrium and a reference sample was aspirated from the descending aorta. Repeated measurements of spinal cord and renal cortical blood flow from the left and right kidneys with three different microsphere colors in five pigs were taken to validate reproducibility. Spinal cord blood flow to the upper thoracic (T1-T4), mid-thoracic (T5-T8), lower thoracic (T9-T13), and lumbar (L1-L3) levels were determined. After euthanasia, we carried out selective vascular corrosion cast and counted the left and right ARMAs from levels T1-T13.

RESULTS

Blood flow analysis of the left and right kidneys revealed a strong correlation (r = .94, p < .001). We detected more left than right ARMAs, with the highest prevalence at T4 (p < .05). The mean number of ARMAs was 8 ± 2. Their number in the upper thoracic region ranged from 2 to 7 (mean of 5 ± 1), while in the lower thoracic region they ranged from 0 to 5 (mean of 3 ± 1 [p < .001]).

CONCLUSIONS

This study shows that combining fluorescence microsphere technique and vascular corrosion cast is well suited for assessing the blood flow and visualizing the arteries at the same time.

A role for spinal cord hypoxia in neurodegeneration

The vascular system of the spinal cord is particularly complex and vulnerable. Damage to the main vessels or alterations to the regulation of blood flow will result in a reduction or temporary cessation of blood supply. The resulting tissue hypoxia may be brief: acute, or long lasting: chronic. Damage to the vascular system of the spinal cord will develop after a traumatic event or as a result of pathology. Traumatic events such as road traffic accidents, serious falls and surgical procedures, including aortic cross-clamping, will lead to an immediate cessation of perfusion, the result of which may not be evident for several days, but may have long-term consequences including neurodegeneration. Pathological events such as arterial sclerosis, venous occlusion and spinal cord compression will result in a progressive reduction of blood flow, leading to chronic hypoxia. While in some situations the initial pathology is exclusively vascular, recent research in neurodegenerative disease has drawn attention to concomitant vascular anomalies in disorders, including amyotrophic lateral sclerosis, spinal muscular atrophy and muscular sclerosis. Understanding the role of, and tissue response to, chronic hypoxia is particularly important in these cases, where inherent neural damage exacerbates the vulnerability of the nervous system to stressors including hypoxia.

Risk factors for spinal cord injury in patients undergoing frozen elephant trunk technique for acute aortic dissection

BACKGROUND

The purpose of this study was to evaluate the risk factors for spinal cord injury (SCI) in patients with acute aortic dissection undergoing surgery with frozen elephant trunk technique (FET).

METHODS

From December 2014 to February 2018, 17 patients with acute aortic dissection underwent surgical treatment of the aortic arch with FET. SCI occurred in 3 patients. Risk factors for SCI were evaluated.

RESULTS

Mean age of the patients was 56 years and 88.2% were male. The ratio of true lumen to total aortic diameter at the level of carina (before: 0.48 vs. after: 0.75, P < 0.001), aortic valve (before: 0.47 vs. after: 0.67, P = 0.001), and celiac artery (before: 0.48 vs. after: 0.68, P = 0.003) increased after surgery. There were no significant differences in perioperative minimum hemoglobin level and postoperative mean arterial pressure between patients with and without SCI. However, patients with SCI had higher creatinine level before surgery (SCI: 1.32 mg/dL vs. no SCI: 0.81 mg/dL, P = 0.023). Although there was no difference in number of patent intercostal arteries before surgery, those originating from the true lumen were fewer in patients with SCI (SCI: 2.7 vs. no SCI: 8.6, P = 0.021). Furthermore, with entry closure, significant decrease in patency was observed in intercostal arteries originating from the false lumen (before: 3.1 vs. after: 1.0, P < 0.001).

CONCLUSION

FET was useful in entry closure. However, FET in patients with higher creatinine level and those who may have significant spinal cord perfusion from the false lumen could be a risk factor for postoperative SCI.

Diagnostic and therapeutic values of intraoperative electrophysiological neuromonitoring during resection of intradural extramedullary spinal tumors: a single-center retrospective cohort and meta-analysis

OBJECTIVE

With the advent of intraoperative electrophysiological neuromonitoring (IONM), surgical outcomes of various neurosurgical pathologies, such as brain tumors and spinal deformities, have improved. However, its diagnostic and therapeutic value in resecting intradural extramedullary (ID-EM) spinal tumors has not been well documented in the literature. The objective of this study was to summarize the clinical results of IONM in patients with ID-EM spinal tumors.

METHODS

A retrospective patient database review identified 103 patients with ID-EM spinal tumors who underwent tumor resection with IONM (motor evoked potentials, somatosensory evoked potentials, and free-running electromyography) from January 2010 to December 2015. Patients were classified as those without any new neurological deficits at the 6-month follow-up (group A; n = 86) and those with new deficits (group B; n = 17). Baseline characteristics, clinical outcomes, and IONM findings were collected and statistically analyzed. In addition, a meta-analysis in compliance with the PRISMA guidelines was performed to estimate the overall pooled diagnostic accuracy of IONM in ID-EM spinal tumor resection.

RESULTS

No intergroup differences were discovered between the groups regarding baseline characteristics and operative data. In multivariate analysis, significant IONM changes (p < 0.001) and tumor location (thoracic vs others, p = 0.018) were associated with new neurological deficits at the 6-month follow-up. In predicting these changes, IONM yielded a sensitivity of 82.4% (14/17), specificity of 90.7% (78/86), positive predictive value (PPV) of 63.6% (14/22), negative predictive value (NPV) of 96.3% (78/81), and area under the curve (AUC) of 0.893. The diagnostic value slightly decreased in patients with schwannomas (AUC = 0.875) and thoracic tumors (AUC = 0.842). Among 81 patients who did not demonstrate significant IONM changes at the end of surgery, 19 patients (23.5%) exhibited temporary intraoperative exacerbation of IONM signals, which were recovered by interruption of surgical maneuvers; none of these patients developed new neurological deficits postoperatively. Including the present study, 5 articles encompassing 323 patients were eligible for this meta-analysis, and the overall pooled diagnostic value of IONM was a sensitivity of 77.9%, a specificity of 91.1%, PPV of 56.7%, and NPV of 95.7%.

CONCLUSIONS

IONM for the resection of ID-EM spinal tumors is a reasonable modality to predict new postoperative neurological deficits at the 6-month follow-up. Future prospective studies are warranted to further elucidate its diagnostic and therapeutic utility.

Spinal Cord Infarction in a Patient Undergoing Veno-arterial Extracorporeal Membrane Oxygenation

Spinal cord infarction is an uncommon, but serious disorder characterized by severe motor impairment and bladder and bowel dysfunction. Spinal cord infarction is likely caused by hypoperfusion at the thoraco-lumbar spinal cord due to diverse reasons. An 81-year-old woman without motor or neurologic dysfunction presented with cardiogenic shock due to acute myocardial infarction. We performed veno-arterial extracorporeal membrane oxygenation (VA ECMO) to maintain adequate organ perfusion. Lower limb weakness was noted on day 1 of ECMO support. Although the symptom persisted, we could not carry out further evaluation because of her hemodynamic instability. After removal of ECMO, spinal magnetic resonance imaging was performed and showed a signal abnormality extending from the level of T5 to the conus medullaris. The patient underwent conservative management, but eventually experienced limb paralysis. Herein, we report a case of spinal cord infarction in a patient with myocardial infarction during VA ECMO support.

High-Risk Surgical Maneuvers for Impending True-Positive Intraoperative Neurologic Monitoring Alerts: Experience in 3139 Consecutive Spine Surgeries

BACKGROUND

Intraoperative neurologic monitoring (IONM) has become an essential component for decreasing the incidence of spinal cord injury during spine surgeries. Many high-risk surgical maneuvers that result in significant IONM alerts have not been reported systematically. Our objective was to thoroughly summarize some common high-risk surgical points associated with IONM alerts in various spine surgeries.

METHODS

Between November 2010 and April 2017, 62 patients with true-positive IONM alerts from 3139 spine surgeries were enrolled. Transcranial motor evoked potentials, somatosensory evoked potentials, and free-run electromyography were used for IONM. All 62 patients were identified as true-positive IONM cases.

RESULTS

Of 3139 patients, 101 demonstrated significant IONM changes-62 true-positive cases, 14 false-positive cases, and 25 indeterminate IONM results. IONM alerts most often occurred in thoracic screw placement (n = 10, 16.1%), osteotomy (n = 22, 35.5%), correction (n = 19, 30.6%), and spinal cord decompression (n = 11, 17.8%). Appropriate timely measures are indicated in response to IONM alerts during high-risk surgical maneuvers. Ten (10/62, 16.1%) patients showed permanent postoperative neurologic deficits.

CONCLUSIONS

IONM alerts are often associated with some specific high-risk surgical maneuvers. Careful and timely observation is crucial.

Acute Isolated Paraplegia Revealing an Ewing Sarcoma of the Thoracic Spine

Ewing sarcoma (ES) infrequently affects the spine. Diagnosis is usually made several weeks following growing symptoms. In this report, we present the case of a child with ES localized at the upper thoracic level. ES was revealed by isolated acute complete paraplegia mimicking medullary stroke. The girl was operated for decompressive laminectomy and tumor removal. Afterwards, she received adjuvant therapy. Subsequently, the child showed a slow improvement of her leg sensitivity associated with a partial motor recovery. ES can affect the mobile spine. Acute symptomatology due to intratumoral hemorrhage and sudden spinal cord compression may suggest the diagnosis. Neurological outcomes following ES are generally poor.

Understanding a role for hypoxia in lesion formation and location in the deep and periventricular white matter in small vessel disease and multiple sclerosis

The deep and periventricular white matter is preferentially affected in several neurological disorders, including cerebral small vessel disease (SVD) and multiple sclerosis (MS), suggesting that common pathogenic mechanisms may be involved in this injury. Here we consider the potential pathogenic role of tissue hypoxia in lesion development, arising partly from the vascular anatomy of the affected white matter. Specifically, these regions are supplied by a sparse vasculature fed by long, narrow end arteries/arterioles that are vulnerable to oxygen desaturation if perfusion is reduced (as in SVD, MS and diabetes) or if the surrounding tissue is hypoxic (as in MS, at least). The oxygen crisis is exacerbated by a local preponderance of veins, as these can become highly desaturated 'sinks' for oxygen that deplete it from surrounding tissues. Additional haemodynamic deficiencies, including sluggish flow and impaired vasomotor reactivity and vessel compliance, further exacerbate oxygen insufficiency. The cells most vulnerable to hypoxic damage, including oligodendrocytes, die first, resulting in demyelination. Indeed, in preclinical models, demyelination is prevented if adequate oxygenation is maintained by raising inspired oxygen concentrations. In agreement with this interpretation, there is a predilection of lesions for the anterior and occipital horns of the lateral ventricles, namely regions located at arterial watersheds, or border zones, known to be especially susceptible to hypoperfusion and hypoxia. Finally, mitochondrial dysfunction due to genetic causes, as occurs in leucodystrophies or due to free radical damage, as occurs in MS, will compound any energy insufficiency resulting from hypoxia. Viewing lesion formation from the standpoint of tissue oxygenation not only reveals that lesion distribution is partly predictable, but may also inform new therapeutic strategies.

Neurologic complications of cardiac and vascular surgery

This chapter will provide an overview of the major neurologic complications of common cardiac and vascular surgeries, such as coronary artery bypass grafting and carotid endarterectomy. Neurologic complications after cardiac and vascular surgeries can cause significant morbidity and mortality, which can negate the beneficial effects of the intervention. Some of the complications to be discussed include ischemic and hemorrhagic stroke, seizures, delirium, cognitive dysfunction, cerebral hyperperfusion syndrome, cranial nerve injuries, and peripheral neuropathies. The severity of these complications can range from mild to lethal. The etiology of complications can include a variety of mechanisms, which can differ based on the type of cardiac or vascular surgery that is performed. Our knowledge about neuropathology, prevention, and management of surgical complications is growing and will be discussed in this chapter. It is imperative for clinicians to be familiar with these complications in order to narrow the differential diagnosis, start early management, anticipate the natural history, and improve outcomes.

A 66-Year-Old Woman with a Progressive, Longitudinally Extensive, Tract Specific, Myelopathy

A 66-year-old woman presented with progressive lancinating pain and sensory deficits attributable to a myelopathy of unclear etiology. Spinal cord magnetic resonance imaging showed a longitudinally extensive T2-hyperintense lesion of the dorsal columns. Comprehensive serum, urine, and cerebrospinal fluid analyses failed to identify an etiology. Empiric intravenous methylprednisolone and intravenous immunoglobulin were of no benefit and serial screens for an occult malignancy were negative. She developed dysesthesias and allodynia affecting her entire body and lost the use of her arms and legs due to severe sensory ataxia that was steadily progressive from onset. She opted against additional aggressive medical management of her condition and passed away on hospice eleven months after symptom onset. Autopsy revealed findings most consistent with polyphasic spinal cord ischemia affecting the dorsal and lateral white matter tracts and, to a lesser extent, adjacent gray matter. The underlying etiology for the progressive vasculopathy remains unknown. Spinal cord ischemia affecting the posterior spinal cord is rare and to our knowledge this case represents the only instance of a progressive spinal cord tractopathy attributable to chronic spinal cord ischemia.

Primary lung tumors invading the chest wall

Chest wall (CW) involvement occurs in approximately 5% of all primary lung neoplasms. According to the most recent TNM classification, lung tumors invading CW are classified as T3, and they represent approximately 45% of all T3 lung cancers. The most common clinical symptom at presentation is chest pain (>60%), which is highly specific of CW infiltration (>90%). Dyspnoea and hemoptysis are also described, especially in case of large lesions. A realistic chance to cure locally advanced tumors invading CW is a surgical resection, consisting in the excision of the primary lung cancer along with the involved CW (sometimes an "en-bloc" resection) and an appropriate lymph-nodal dissection. However, such patients are at high-risk of facing postoperative complications; prognosis mainly depends on: (I) the completeness of resection; and (II) the lymph-nodal involvement. Hence, due to these reasons (incidence, symptoms, prognosis, post-operative complications), such category of patients are to be carefully assessed preoperatively and if deemed practicable, surgery should be taken into consideration. In this view, the aim of this paper is to critically review the most recent series of lung tumors invading the CW, with a particular focus on patients' preoperative evaluation, surgical techniques, postoperative complications and overall outcome.

Two-staged Correction of Severe Congenital Scoliosis Associated With Intraspinal Abnormalities

STUDY DESIGN

A retrospective study.

OBJECTIVE

To analyze the efficacy and safety of perioperative halo-gravity traction as an adjunct to posterior vertebral column resection (PVCR) in the treatment of patients with severe congenital scoliosis and coexisting asymptomatic intraspinal pathologies (diastematomyelia and/or tethered cord).

SUMMARY OF BACKGROUND DATA

Few reports to our knowledge review the use of perioperative halo-gravity traction and PVCR in this patient population.

MATERIALS AND METHODS

A total of 17 patients with a minimum 2-year follow-up who underwent PVCR using perioperative halo-gravity traction were analyzed. Patients were analyzed by age at date of examination (range, 11-23 y; mean, 14.4 y), sex (7 male, 10 female), major coronal curve magnitude (range, 108-149 degrees; average, 125 degrees), major sagittal curve magnitude (range, 72-118 degrees; average, 91 degrees). Complications related to halo traction and PVCR were reviewed.

RESULTS

Radiographic outcomes demonstrated Cobb angle of major curve had an average correction of 28% after halo traction and it measured 53 degrees (range, 42-84 degrees) at the last follow-up, for a 58% correction. Maximal kyphosis improved to 58 degrees (range, 43-76 degrees) at ultimate follow-up. There were no permanent neurological deficits in this series.

CONCLUSIONS

The study results suggested that surgical treatment for intraspinal abnormality may be unnecessary in asymptomatic patients with severe congenital scoliosis who are undergoing scoliosis corrective surgery. PVCR combined with perioperative traction is a safe and effective alternative for such patients.

Immediate ICU Care for Patients Following Aortic Arch Surgery

Patients undergoing aortic arch surgery are at high risk for stroke, delirium, low cardiac output, respiratory failure, renal failure, and coagulopathy. A significantly higher mortality is seen in patients experiencing any of these complications when compared with those without complications. As surgical, perfusion, and anesthetic techniques improve, the incidence of major complications have decreased. A recent paradigm shift in cardiac surgery has focused on rapid postoperative recovery, and a similar change has affected the care of patients after arch surgery. Nevertheless, a small subset of patients experience significant morbidity and mortality after aortic arch surgery, and rapid identification of any organ dysfunction and appropriate supportive care is critical in these patients. In this article, the current state of postoperative care of the patient after open aortic arch surgery will be reviewed.

Cause and prevention of demyelination in a model multiple sclerosis lesion

Objective

Demyelination is a cardinal feature of multiple sclerosis, but it remains unclear why new lesions form, and whether they can be prevented. Neuropathological evidence suggests that demyelination can occur in the relative absence of lymphocytes, and with distinctive characteristics suggestive of a tissue energy deficit. The objective was to examine an experimental model of the early multiple sclerosis lesion and identify pathogenic mechanisms and opportunities for therapy.

Methods

Demyelinating lesions were induced in the rat spinal dorsal column by microinjection of lipopolysaccharide, and examined immunohistochemically at different stages of development. The efficacy of treatment with inspired oxygen for 2 days following lesion induction was evaluated.

Results

Demyelinating lesions were not centered on the injection site, but rather formed 1 week later at the white–gray matter border, preferentially including the ventral dorsal column watershed. Lesion formation was preceded by a transient early period of hypoxia and increased production of superoxide and nitric oxide. Oligodendrocyte numbers decreased at the site shortly afterward, prior to demyelination. Lesions formed at a site of inherent susceptibility to hypoxia, as revealed by exposure of naive animals to a hypoxic environment. Notably, raising the inspired oxygen (80%, normobaric) during the hypoxic period significantly reduced or prevented the demyelination.

Interpretation

Demyelination characteristic of at least some early multiple sclerosis lesions can arise at a vascular watershed following activation of innate immune mechanisms that provoke hypoxia, and superoxide and nitric oxide formation, all of which can compromise cellular energy sufficiency. Demyelination can be reduced or eliminated by increasing inspired oxygen to alleviate the transient hypoxia. Ann Neurol 2016;79:591–604

Diagnosis and management of hemoptysis

Hemoptysis is the expectoration of blood that originates from the lower respiratory tract. It is usually a self-limiting event but in fewer than 5% of cases it may be massive, representing a life-threatening condition that warrants urgent investigations and treatment. This article aims to provide a comprehensive literature review on hemoptysis, analyzing its causes and pathophysiologic mechanisms, and providing details about anatomy and imaging of systemic bronchial and nonbronchial arteries responsible for hemoptysis. Strengths and limits of chest radiography, bronchoscopy, multidetector computed tomography (MDCT), MDCT angiography and digital subtraction angiography to assess the cause and lead the treatment of hemoptysis were reported, with particular emphasis on MDCT angiography. Treatment options for recurrent or massive hemoptysis were summarized, highlighting the predominant role of bronchial artery embolization. Finally, a guide was proposed for managing massive and nonmassive hemoptysis, according to the most recent medical literature.

Nontraumatic spinal cord ischaemic syndrome

This study presents the clinical features and functional outcomes of eight consecutive patients who were admitted to our institution between 2012 and 2014 with nontraumatic spinal cord infarction (SCI), a rare and devastating condition. We also present a literature review of aetiologies and prognostic factors relevant to our case series. The mean age of our cohort was 64 years and five patients were female. Aortic disease was causative in three, including one patient with biopsy confirmed giant cell arteritis. Fibrocartilaginous embolism was a possible aetiology in two others, anterior spinal artery aneurysm in one, and the cause was undetermined in two patients. American Spinal Injury Association impairment scale (ASIA) scores at nadir (time of maximum severity of signs) were B in three, C in three and D in two patients (all were wheelchair dependent). At last follow-up, ASIA scores were C in one, D in five and E in one patient. One patient died, two remained wheelchair dependent, four required a walking aid or frame and one was mobilising independently. A literature review of 11 patient series of nontraumatic SCI found that prognosis is primarily determined by the severity of motor or sensory involvement, in particular, initial and nadir ASIA A/B scores which strongly correlate with poor outcome. In the majority of series, 40-60% of patients had initial ASIA A/B scores with a similar proportion remaining wheelchair dependent on follow-up. Most patients in our cohort had nadir ASIA C/D scores, which may explain their better outcomes.

Relationship Between Regional Atherosclerosis and Adjacent Spinal Cord Histology

INTRODUCTION

Scant data are available regarding ischemic insult to the spinal cord and the responsible blood supply. Therefore, we aimed to investigate a correlation between atherosclerosis of adjacent vessels and spinal cord ischemia.

MATERIALS AND METHODS

In 20 unembalmed adult cadavers, samples of the vertebral arteries and aorta were removed and the degree of atherosclerosis with subsequent luminal occlusion was histologically analyzed. Next, adjacent segments of the spinal cord were harvested and submitted for immunohistological analysis of both neural and glial elements and blood supply.

RESULTS

We identified proximal atherosclerosis in the majority of cadavers but with varying degrees of luminal occlusion. The greatest degree of luminal occlusion was found in the descending abdominal aorta. No specimen was found to have atherosclerosis of the anterior or posterior spinal or radicular arteries. No spinal cord histology showed signs of ischemia, even in specimens with a significant large parent vessel (vertebral artery and aorta) occlusion due to atherosclerosis. Neuropathology of these adjacent cord segments revealed no signs of ischemia or demyelination.

CONCLUSIONS

Spinal cord ischemia is often misdiagnosed and can cause significant neurological compromise. However, based on our study, the degree of atherosclerosis of the adjacent parent vessel supply does not appear to be  a predictor of neuronal and glial tissue damage of the adjacent spinal cord.

The cutoff amplitude of transcranial motor evoked potentials for transient postoperative motor deficits in intramedullary spinal cord tumor surgery

STUDY DESIGN

Retrospective clinical study of intraoperative transcranial motor evoked potential (TcMEP) amplitudes and postoperative motor deficits (PMDs).

OBJECTIVE

To determine the quantifiable cutoff amplitude of TcMEP for predicting transient PMDs in intramedullary spinal cord tumor (IMSCT) surgery.

SUMMARY OF BACKGROUND DATA

The "presence or absence" criterion is reliable and widely used the alarm criterion for preventing permanent PMDs in IMSCT surgery. However, we wanted to prevent PMDs even if it is transient. The cutoff amplitude for transient PMDs should be identified.

METHODS

We conducted a retrospective study to identify the cutoff amplitude for predicting transient PMDs in IMSCT surgery. Thirty-seven patients were included in the study. We examined intraoperative electrophysiological changes and perioperative motor status in these patients. Receiver operating characteristic analyses were performed to identify the cutoff amplitudes for predicting transient PMDs in IMSCT surgery. The incidence of PMDs and cutoff TcMEP amplitude in cervical and thoracic lesions were compared.

RESULTS

Thirteen cases demonstrated transient PMDs. Among 280 monitorable muscles in 37 cases, 51 muscles in 13 patients showed PMDs. Through receiver operating characteristic analysis, the relative and the absolute cutoff amplitudes at the intraoperative point of deterioration were identified to be 12% residual of baseline amplitude and 3.2 μV, respectively. Sensitivity/specificity for those cutoff points are 86%/74% and 88%/78%, respectively. The incidence of PMD was significantly higher, and the cutoff amplitude was lower in the thoracic lesions than in the cervical lesions.

CONCLUSION

We determined the cutoff TcMEP amplitude for predicting transient PMDs in IMSCT surgery. The cutoff amplitude for the cervical lesions was higher than that for the thoracic lesions. The results suggest the need for setting different alarm criteria in different level of spine.

LEVEL OF EVIDENCE

3.

Paraplegic neurodeficit management post endovascular graft: a rare case of aortic dissection

Acute aortic dissection is a catastrophic episode that usually presents as a sudden, painful, ripping sensation in the chest or back. It is associated with neurologic sequelae in as many as one-third of patients. We report a case of aortic dissection, presenting as acute paraplegia. A 50-year-old patient presented to us with chief complaints of paraplegia and back pain. On examination, strength was 5/5 in both upper extremities and 0/5 in both lower extremities. Deep tendon reflexes were absent in her legs. CT angiogram of aorta Aortic Dissection Stanford type B / De-Bakey type -III. Patient was treated with endovascular graft for aortic dissection, paraplegia recovered completely.

Arterial peculiarities of the thoracolumbar spinal cord in rabbit

The aim of this study was to investigate the arterial blood supply of the thoracolumbar spinal cord in rabbit. The study was carried out on twenty adult New Zealand white rabbits. Ten rabbits were used in the corrosion technique and ten rabbits in the dissection technique. After the killing, the vascular network was perfused with saline. Batson's corrosion casting kit no. 17 © was used as a casting medium. After polymerisation of the medium, in ten rabbits the maceration was carried out in KOH solution, and in ten other rabbits, formaldehyde was injected by the dissection technique into the vertebral canal. We found high variability of segmental arteries supplying blood to the spinal cord. There are 12 intercostal arteries and 1 costo-abdominal artery. Dorsal branches arising from the dorsal surface of the aorta thoracica were found as follows: in 70% of the cases, 9 pairs were present; in 20% of the cases 8 pairs; and in 10% of the cases 10 pairs. The paired arteriae lumbales were present in 6 pairs in 90% of the cases and in 5 pairs in 10% of the cases. On the dorsal surface of spinal cord, we found two irregular longitudinal arteries in 70% of the cases, no longitudinal arteries in 20% of the cases and three irregular longitudinal arteries in 10% of the cases receiving dorsal branches of rami spinales. Among the dorsal branches observed in the thoracic region, 60.5% were left-sided, 39.5% right-sided and in the lumbar region, 52.5% were left-sided and 47.5% right-sided.

Surfer's myelopathy: a radiologic study of 23 cases

BACKGROUND AND PURPOSE

Surfing is an uncommon cause of an acute nontraumatic myelopathy. This study describes the MR imaging characteristics and clinical correlates in 23 subjects with surfer's myelopathy.

MATERIALS AND METHODS

This was a retrospective review of 23 cases of surfer's myelopathy from 2003-2012. Spinal cord MR imaging characteristics and neurologic examinations with the use of the American Spinal Injury Association scale were reviewed. Logistic regression was used to determine associations between MR imaging characteristics, American Spinal Injury Association scale, and clinical improvement.

RESULTS

All subjects (19 male, 4 female; mean age, 26.3 ± 7.4 years) demonstrated "pencil-like," central T2-hyperintense signal abnormalities in the spinal cord extending from the midthoracic region to the conus with associated cord expansion and varying degrees of conus enlargement on spinal cord MR imaging within 24 hours of symptom onset. T1 signal was normal. Faint gadolinium enhancement was present in a minority. Although there was a strong correlation between initial American Spinal Injury Association score and clinical improvement (P = .0032), MR imaging characteristics were not associated with American Spinal Injury Association score or clinical improvement.

CONCLUSIONS

Surfer's myelopathy should be considered in the radiographic differential diagnosis of a longitudinally extensive T2-hyperintense spinal cord lesion. MR imaging characteristics do not appear to be associated with severity on examination or clinical improvement.

Extensive resections: pancoast tumors, chest wall resections, en bloc vascular resections

Infiltration by lung tumor of adjacent anatomic structures including major vessels, main bronchi, and chest wall not only influences the oncologic severity of the disease but also increases the technical complexity of surgery, requiring extended resections and demanding reconstructive procedures. Completeness of resection represents in every case one of the main factors influencing the long-term outcome of patients. Technical and oncologic aspects of extended operations, including resection of Pancoast tumors and chest wall, bronchovascular sleeve resections, and en bloc resections of major thoracic vessels, are reported in this article.

Neurological complications of thoracic endovascular aortic repair

Thoracic endovascular aortic repair (TEVAR) has decreased the morbidity and mortality associated with open surgical repair of descending thoracic aortic diseases, but important complications unique to the procedure remain. Spinal cord ischemia and infarction is a recognized complication caused by endovascular coverage or injury to spinal cord collateral vessels. Stroke is a consequence of thromboembolism or coverage of aortic arch branch vessels with insufficient collateral circulation. Understanding the risk factors and the pathophysiology of neurological complications of TEVAR are important for the successful anesthetic and surgical management and treatment of patients undergoing endovascular procedures involving the thoracic aorta.

Biochanin A reduces drug-induced p75NTR expression and enhances cell survival: a new in vitro assay for screening inhibitors of p75NTR expression

Following spinal cord injury (SCI) or peripheral neuropathy, increased levels of the p75(NTR) death receptor initiate the signal transduction cascade leading to cell death. Investigations of compounds that may ameliorate neuronal cell death have largely used rodent models, which are time consuming, expensive, and cumbersome to perform. Previous studies had demonstrated that steroids, particularly dexamethasone and its analog methylprednisolone sodium succinate, exhibit limited neuroprotective effects against neuronal injury. Significantly, many naturally occurring nonsteroidal plant compounds exhibit structural overlap with steroids. In this report, we present an in vitro cellular screen model to practically examine the efficacy of various phytoestrogens in modulating the ibuprofen-induced expression of p75(NTR) and reduced cell survival of CCFSTTG1 and U87MG cells in a rescue (postinjury) or prevention (preinjury) regimen. We show that the phytoestrogen, biochanin A, and, to a lesser extent, genistein are more effective than dexamethasone at reducing p75(NTR) expression and improving the viability of U87MG and CCFSTTG1 before and after p75(NTR) induction. Furthermore, these studies implicate biochanin A's inactivation of p38-MAPK as a possible contributor to reducing p75(NTR) with associated increased cell survival. This new in vitro assay facilitates a more time-efficient screening of compounds to suppress p75(NTR) expression and increase neuronal cell viability prior to their evaluation in animal models of neurological diseases.

Spinal cord ischemia following thoracotomy without epidural anesthesia

PURPOSE

Paraplegia is an uncommon yet devastating complication following thoracotomy, usually caused by compression or ischemia of the spinal cord. Ischemia without compression may be a result of global ischemia, vascular injury and other causes. Epidural anesthesia has been implicated as a major cause. This report highlights the fact that perioperative cord ischemia and paraplegia may be unrelated to epidural intervention.

CLINICAL FEATURES

A 71-yr-old woman was admitted for a left upper lobectomy for resection of a non-small cell carcinoma of the lung. The patient refused epidural catheter placement and underwent a left T5-6 thoracotomy under general anesthesia. During surgery, she was hemodynamically stable and good oxygen saturation was maintained. Several hours following surgery the patient complained of loss of sensation in her legs. Neurological examination disclosed a complete motor and sensory block at the T5-6 level. Magnetic resonance imaging (MRI) revealed spinal cord ischemia. The patient received iv steroid treatment, but remained paraplegic. Five months following the surgery there was only partial improvement in her motor symptoms. A follow-up MRI study was consistent with a diagnosis of spinal cord ischemia.

CONCLUSION

In this case of paraplegia following thoracic surgery for lung resection, epidural anesthesia/analgesia was not used. The MRI demonstrated evidence of spinal cord ischemia, and no evidence of cord compression. This case highlights that etiologies other than epidural intervention, such as injury to the spinal segmental arteries during thoracotomy, should be considered as potential causes of cord ischemia and resultant paraplegia in this surgical population.

Multi-detector row CT of hemoptysis

Hemoptysis is symptomatic of a potentially life-threatening condition and warrants urgent and comprehensive evaluation of the lung parenchyma, airways, and thoracic vasculature. Multi-detector row computed tomographic (CT) angiography is a very useful noninvasive imaging modality for initial assessment of hemoptysis. The combined use of thin-section axial scans and more complex reformatted images allows clear depiction of the origins and trajectories of abnormally dilated systemic arteries that may be the source of hemorrhage and that may require embolization. Conditions such as bronchiectasis, chronic bronchitis, lung malignancy, tuberculosis, and chronic fungal infection are some of the most common underlying causes of hemoptysis and are easily detected with CT. "Cryptogenic" hemoptysis is common among smokers and warrants subsequent follow-up imaging to exclude possible underlying malignancy. The bronchial arteries are the source of bleeding in most cases of hemoptysis. Contributions from the non-bronchial systemic arterial system represent an important cause of recurrent hemoptysis following apparently successful bronchial artery embolization. Vascular anomalies such as pulmonary arteriovenous malformations and bronchial artery aneurysms are other important causes of hemoptysis. Multi-detector row CT angiography permits noninvasive, rapid, and accurate assessment of the cause and consequences of hemorrhage into the airways and helps guide subsequent management.