Prevention and management of spinal cord ischemia following aortic surgery: A survey of contemporary practice.

OBJECTIVE: Spinal cord ischemia (SCI) is a devastating complication of thoracoabdominal aortic aneurysm repair. We aim to characterize current practices pertaining to SCI prevention and treatment across Canada. METHODS: Two questionnaires were developed by the Canadian Thoracic Aortic Collaborative and the Canadian Cardiovascular Critical Care Society targeting aortic surgeons and intensivists. A list of experts in the management of patients at risk of SCI was developed, with representation from each of the Canadian centers that perform complex aortic surgery. RESULTS: The response rate was 91% for both intensivists (21/23), and from cardiac and vascular surgeons (39/43). Most surgeons agreed that staging is important during endovascular repair of extent II thoracoabdominal aortic aneurysm (60%) but not for open repair (34%). All of the surgeons felt prophylactic lumbar drains were effective in reducing SCI, whereas only 66.7% of intensivists felt that lumbar drains were effective (P < .001). There was consensus among surgeons over when to employ lumbar drains. A majority of surgeons preferred to keep the hemoglobin over 100 g/L if the patient demonstrated loss of lower-extremity function, whereas most intensivists felt a target of 80 g/L was adequate (P < .001). Management of perioperative antihypertensives, use of intraoperative adjuncts, and management of venous thromboembolism prophylaxis in the presence of a lumbar drain, were highly variable. CONCLUSIONS: We observed some consensus but considerable variability in the approach to SCI prevention and management across Canada. Future studies focused on the areas of variability may lead to more consistent and improved care for this high-risk population.

Massive Lumbar Disk Herniation Following "Therapeutic" Water Boiling of the Lower Extremities: Case Report and Literature Review.

BACKGROUND: Legs burning for treating lumbar radicular pain are still in use nowadays in low socioeconomical environments. They are dangerous as the case we report shows clearly. CLINICAL CASE: A 49-year-old man came to our attention with severe flaccid paraparesis occurred 10 days before, almost immediately after he had immersed his legs in boiling water to treat his severe left lumbocrural pain. This was known to be due to a right L3/4 herniated disk diagnosed by magnetic resonance imaging. At the examination he showed severe motor paresis and absent reflexes of his lower limbs, while crural pain was mild and sensation and urinary function were unaffected. The results of his neurologic examination led us to suspect an acute motor axon degeneration related to thermal shock. Lumbar magnetic resonance imaging, performed before the planned electromyogram as an exception to the established routine, showed instead a giant 5- × 5.5-cm, herniated disk compressing the dural sac at L3. CONCLUSIONS: Prompt surgical decompression led to rapid improvement. We discuss here the pathophysiology of this unusual case and point out how medieval practices for treating sciatica-like pain are not only unjustified from a medical viewpoint but also potentially dangerous.

Intercostal Artery Reconstruction: The Simple and Effective Technique on Spinal Cord Protection during Thoracoabdominal Aortic Replacement.

BACKGROUND: To retrospectively analyze the role of intercostal artery reconstruction in the spinal cord protection for patients undergoing extensive thoracoabdominal aortic aneurysm repair. METHODS: From August 2007 to 2014, thoracoabdominal aortas (Crawford II) of 81 consecutive patients with mean age 39.4 ± 10.32 years were repaired. Seventy-three of these patients (90.12%) were diagnosed with aortic dissection in our group, 25 (30.86%) with Stanford type A dissection and 48 (59.26%) with Stanford B aortic dissection. All 25 patients with type A dissection have previously undergone surgical procedures which include Bentall's procedures in 11 cases, ascending aortic replacement in 6 cases, and total aortic arch replacement in 8 cases. All procedures were performed under profound hypothermia with interval cardiac arrest after making a thoracoabdominal incision. Extracorporeal circulation was instituted with 2 arterial cannulae and a single venous cannula in the right atrium. T6-T12 intercostal arteries and L1 and L2 lumbar arteries were formed to a neo-intercostal artery in place and were connected to an 8 mm branch for maintaining spinal cord blood perfusion. Visceral arteries were joined into a patch and anastomosed to the end of the main graft. The left renal artery was anastomosed to an 8 mm branch or joined to the patch. The other 10 mm branches were anastomosed to iliac arteries. RESULTS: With 100% follow-up, early mortality was 7.4%. Six deaths were recorded; 1 patient died of cerebral hemorrhage, 3 of renal failure, 1 of heart failure because of myocardial infarction, and the last one died from the rupture of celiac artery dissection. The rate of postoperative spinal cord deficits was 3.7%, 2 patients with paraplegia and 1 patient with paraparesis. None had bladder or rectum dysfunction. Neo-intercostal arteries were clogged in 12 patients within follow-up period and formed pseudoaneurysm in 2 patients with Marfan syndrome. The mean survival time in this group was 54.22 ± 3.03 months (95% confidence interval 44.37-59.90 months) with survival rate of 92.37% after 1 year, 89.02% after 2 years, and 85.54% after 5 years. All patients were free from spinal cord deficits. CONCLUSIONS: Intercostal artery reconstruction is an effective technique for spinal cord protection in patients with the thoracoabdominal aortic repair. It can achieve favorable results and avoid spinal cord deficits with long-term follow-up.

Intraoperative neuroprotective interventions prevent spinal cord ischemia and injury in thoracic endovascular aortic repair.

OBJECTIVE: Transient and permanent paraparesis and paraplegia (spinal cord injury [SCI]) are reported in up to 13% of patients undergoing thoracic endovascular aortic repair (TEVAR) for descending thoracic aortic aneurysm, thoracoabdominal aortic aneurysm, and thoracic aortic dissection. We hypothesize that aggressive intraoperative and postoperative neuroprotective interventions prevent or significantly reduce all SCI in TEVAR. METHODS: Using a prospectively maintained, Institutional Review Board-approved database, we retrospectively reviewed all TEVARs performed in a university tertiary referral center from 2005 to 2014 to study the incidence of all transient and permanent lower extremity SCI. Only TEVARs for traumatic aortic tear were excluded. Arch debranching and carotid subclavian bypass were performed before TEVAR in patients with arch involvement. All patients had moderate systemic hypothermia (34°C), mean arterial pressure ≥90 mm Hg, and hemoglobin ≥10 g/dL. Patients received mannitol (12.5 g), methylprednisolone (30 mg/kg), and naloxone (1 µg/kg/h). Patients in whom >12 cm of aortic coverage was planned had spinal fluid drained to a pressure of <8 mm Hg intraoperatively and postoperatively until normal leg strength was confirmed. The main outcome measure was transient or permanent SCI. RESULTS: One hundred fifty-five patients had TEVAR between 2005 and 2014. Mean age was 74 years, and 56.1% were male. Descending thoracic aortic aneurysm was present in 91.6%, thoracoabdominal aortic aneurysm in 8.4%, and dissection in 28.8%. Presentation was acute in 42.5%. The procedure included carotid-subclavian bypass in 18.7% of patients. Seventy-two percent of patients had spinal fluid drainage. Mean aortic coverage was 25 cm. Eighty-one percent of patients had >12 cm aortic coverage, and 49% had complete coverage of the thoracic aorta (coverage from subclavian to celiac artery). In-hospital mortality was 1.94%. Stroke occurred in 1.32% of patients. No patient had renal failure. SCI occurred in 0.65% (1 of 154) of patients. CONCLUSIONS: SCI in TEVAR can be significantly reduced by using proactive intraoperative and postoperative neuroprotective interventions that prolong spinal cord ischemic tolerance and increase spinal cord perfusion and oxygen delivery.

The effect of intercostal artery reimplantation on spinal cord injury in thoracoabdominal aortic aneurysm surgery.

OBJECTIVE: Intercostal artery (ICA) reimplantation (ICAR) is thought to decrease spinal cord injury (SCI) in thoracic aortic aneurysm and thoracoabdominal aortic aneurysm (TAAA) surgery. Patients treated from 1989 to 2005 without ICAR were compared with those treated from 2005 to 2013 with ICAR to determine whether ICAR reduced SCI. We hypothesized that ICAR would reduce SCI, especially in the highest-risk patients. METHODS: This was a retrospective analysis using a prospectively maintained Investigational Review Board-approved database from a university tertiary referral center. The analysis included all patients (n = 805) undergoing thoracic aortic aneurysm and TAAA surgery from 1989 to 2013. The main outcome measure was any transient or permanent paraplegia or paraparesis (SCI). From 1989 to 2004, ICAR was not performed in patients, and open ICAs were ligated; from 2005 to 2013, open ICAs at T7 to L2 were reimplanted in patients with Crawford type I, II, and III TAAAs. Surgical technique was cross clamp without assisted circulation. Anesthetic management was the same from 1989 to 2013. Demographic, intraoperative, and outcome variables were assessed by univariate and multivariate analysis. Observed/expected ratios for paralysis were calculated. RESULTS: A total of 540 patients had surgery before 2005, and 265 had surgery after 2005, when ICAR was begun. There were 275 type I, II, and III TAAAs before 2005 and 164 after 2005. Aneurysm extent, acuity, SCI, mortality, renal failure, and pulmonary failure were the same in patients treated before and after 2005. Multivariate modeling of all patients showed type II TAAA (P = .0001), dissection (P = .00015), and age as a continuous variable (P = .0085) were significant for SCI. Comparing only type I, II, and III TAAAs, there was no difference in SCI between those with ICAR after 2005 and those without ICAR before 2005 (5.1% vs 8.8%; P = .152). In a subanalysis of the highest-risk patients (type II, dissection, acute), ICAR was not significant (P = .27). Observed/expected ratios ratios were 0.23 before 2005 and 0.16 after 2005 (χ2 = .796; P = .37). CONCLUSIONS: Although there was a small decrease in SCI with ICAR, reattaching ICAs did not produce a statistically significant reduction in SCI, even in the highest-risk patients.

Bee Venom Acupuncture Alleviates Experimental Autoimmune Encephalomyelitis by Upregulating Regulatory T Cells and Suppressing Th1 and Th17 Responses.

The protective and therapeutic mechanism of bee venom acupuncture (BVA) in neurodegenerative disorders is not clear. We investigated whether treatment with BVA (0.25 and 0.8 mg/kg) at the Zusanli (ST36) acupoints, located lateral from the anterior border of the tibia, has a beneficial effect in a myelin basic protein (MBP)(68-82)-induced acute experimental autoimmune encephalomyelitis (EAE) rat model. Pretreatment (every 3 days from 1 h before immunization) with BVA was more effective than posttreatment (daily after immunization) with BVA with respect to clinical signs (neurological impairment and loss of body weight) of acute EAE rats. Treatment with BVA at the ST36 acupoint in normal rats did not induce the clinical signs. Pretreatment with BVA suppressed demyelination, glial activation, expression of cytokines [interferon (IFN)-γ, IL-17, IL-17A, tumor necrosis factor-alpha (TNF-α), and IL-1ß], chemokines [RANTES, monocyte chemotactic protein-1 (MCP-1), and macrophage inflammatory protein (MIP)-1α], and inducible nitric oxide synthase (iNOS), and activation of p38 mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB (p65 and phospho-IκBα) signaling pathways in the spinal cord of acute EAE rats. Pretreatment with BVA decreased the number of CD4(+), CD4(+)/IFN-γ(+), and CD4(+)/IL-17(+) T cells, but increased the number of CD4(+)/Foxp3(+) T cells in the spinal cord and lymph nodes of acute EAE rats. Treatment with BVA at six placebo acupoints (SP9, GB39, and four non-acupoints) did not have a positive effect in acute EAE rats. Interestingly, onset and posttreatment with BVA at the ST36 acupoint markedly attenuated neurological impairment in myelin oligodendrocyte glycoprotein (MOG)(35-55)-induced chronic EAE mice compared to treatment with BVA at six placebo acupoints. Our findings strongly suggest that treatment with BVA with ST36 acupoint could delay or attenuate the development and progression of EAE by upregulating regulatory T cells and suppressing T-helper (Th) 17 and Th1 responses. These results warrant further investigation of BVA as a treatment for autoimmune disorders of the central nervous system.

Efficacy of right axillary artery perfusion for antegrade cerebral perfusion in open total arch repair.

OBJECTIVE: Right axillary artery (RAxA) perfusion was introduced for selective antegrade cerebral perfusion in total aortic arch repair to prevent cerebral embolism derived from arterial cannulation. However, the strategic benefits and long-term results regarding the cannulation site remain controversial. We retrospectively compared the outcomes between propensity score-matched patients with and without using RAxA cannulation. METHODS: Between 2006 and 2012, 260 consecutive patients underwent total arch repair with antegrade cerebral perfusion and moderate hypothermia at a single institution. RAxA cannulation was added in 142 patients (54.6%), and 70 propensity score-matched pairs were obtained. RESULTS: There were no significant differences in 30-day (2.9% [2 of 70] vs 5.7% [4 of 70]; P = .415 and in-hospital death (5.7% [4 of 70] vs 5.7% [4 of 70]; P = 1.000) between matched pairs. Although there was no significant difference in the occurrence of postoperative stroke (8.6% [6 of 70] vs 8.6% [6 of 70]; P = 1.000), the new rate of new occurrence of postoperative paraparesis was lower in patients with RAxA perfusion (0% [0 of 70] vs 4.3% [3 of 70]; P = .067). With a mean follow-up period of 1057 ± 686 days, the overall 5-year survival was 90.6% and was 89.6% for patients with RAxA perfusion. Thee difference in survival between patients with and without RAxA perfusion was not significant. CONCLUSIONS: RAxA perfusion is a useful option for total aortic arch repair, and the midterm outcomes were satisfactory. However, RAxA perfusion did not completely prevent stroke in patients with an atherothrombotic aorta.

Trehalose protects against spinal cord ischemia in rabbits.

OBJECTIVE: This study tested to see if trehalose, a cytoprotective disaccharide, protects against spinal cord ischemia in a rabbit model. METHODS: The infrarenal aorta was mobilized in four groups of 10 rabbits. In groups I, II, and III, it was clamped proximally and distally for 20 minutes. In group I, the clamped aorta was infused at 2.5 L/min for 2 hours with lactated Ringer's (LR) solution. In group II, the clamped aorta was infused with 5% trehalose in LR. LR was administered intravenously (2.0 mL/min) in groups I and II starting 30 minutes before clamping. In group III, 5% trehalose in LR was infused intravenously only. Group IV was a sham-operated control group without aortic clamping. At 8, 24, and 48 hours after reperfusion, hind limb function was scored using the Tarlov score (paralysis = 0, perceptible joint movement = 1, good joint movement but unable to stand = 2, able to walk = 3, normal = 4). Histologic analysis and electron microscopy were performed on anterior horn cells. RESULTS: The Tarlov scores in groups I, II, and III were, respectively, 1.1 ± 1.4, 3.5 ± 0.5, and 2.9 ± 0.9 at 8 hours; 0.8 ± 1.2, 3.9 ± 0.3, and 2.9 ± 0.9 at 24 hours; and 0.6 ± 0.7, 3.9 ± 0.3, and 2.7 ± 0.9 at 48 hours after reperfusion. Group IV scores were normal (4 ± 0) at all assessments. These scores were higher in groups II and III than in group I (P < .01) at all assessments. Scores at 24 and 48 hours were higher in group II than in group III (P < .05). In group III, delayed paraparesis developed in one rabbit at 24 hours and in two more at 48 hours. Histopathologic analysis showed the number of normal neurons was higher in groups II (P < .0001), III (P = .006), and IV (P < .0001) vs group I. Electron microscopy confirmed preserved neuronal cell ultrastructure in rabbits with normal limb function. CONCLUSIONS: Transaortic trehalose infusion was protective against paraplegia, whereas intravenous trehalose reduced spinal cord ischemia. This study was preliminary and further studies are needed.

[Tuberculous spondylitis of vertebra with fracture, paraparesis and pleural empyema complications--case report].

INTRODUCTION: Spine tuberculosis is caused by Micobacterium tuberculosis. It is localized in the vertebral body or intervertebral disc. Its diagnosis is often delayed because of nonspecific symptoms and neglected presence of tuberculosis, which leads to serious complications. CASE REPORT: This paper presents a case of tuberculous spondylitis, which was complicated with the fracture of vertebra, paraparesis of lower extremities and pleural empyema. The treatment with antituberculous drugs started after the fracture of 10th and 11th thoracic vertebras. The therapy brought some improvement but paraparesis of lower extremities remained. In the further course of disease, inflammatory process affected the pleura. Antibiotic and antitubercular therapy with puncture of pleura were not very effective. Operation was performed on December 20th 2011: Thoracotomia lat. dex. Decorticatio pulmonum lat.dex. Seven months after surgery, the patient was without symptoms. CONCLUSION: Tuberculous spondylitis occurs relatively frequently in clinical practice. Early diagnosis and adequate therapy of this disease can prevent the occurrence of its serious complications.

Somatosensory-evoked potential-guided intercostal artery reimplantation in thoracoabdominal aortic aneurysm surgery.

OBJECTIVE: This study was undertaken to evaluate the use of somatosensory-evokedpotential (SSEP) monitoring on intercostal artery reimplantation (IAR) and spinal cord ischemia rates during thoracoabdominal ortic aneurysm repair. METHODS: Fifty-two patients had thoracoabdominal aortic aneurysm repair with IAR under SSEP guidance and 79 patients had repair with routine IAR without SSEP guidance from 1999 to 2010. RESULTS: No differences were observed between the two groups in age (63.1 ± 11.6 vs 64.8 ± 9.8 years), sex (57.7% vs 50.6% men), chronic dissections (40.4% vs 44.3%), renal insufficiency (11.5% vs 10.1%), and Crawford type 1 and 2 aneurysms (53.9% vs 53.9%). There was one case (1.9%) of immediate paraplegia and one case (1.9%) of delayed paraplegia in the SSEP group versus 2 cases (2.5%) of immediate paraplegia in the non-SSEP group (P = 0.92). In the SSEP group, 38 patients (73.1%) had SSEP changes, but only 15 (28.8%) required reimplantation. There were fewer IARs in the SSEP group compared with the non-SSEP group (28.8% vs. 59.5%, P = 0.004). No difference was observed in 30-day mortality between the SSEP and the non-SSEP group (3.9% vs. 7.6%, P = 0.48). CONCLUSIONS: The use of SSEP monitoring led to a significant decrease in the need for IAR without increasing the paraplegia rate.

The use of spinal angiography in the management of posterior mediastinal tumors: case series and review of the literature.

INTRODUCTION: Resection of inferiorly located posterior mediastinal tumors can be complicated by their proximity to the artery of Adamkiewicz (AKA). Although uncommon, intraoperative injury to the AKA may result in paraparesis or paralysis secondary to spinal cord ischemia. The use of preoperative spinal angiography may serve as a useful adjunct to the surgeon in guiding extent of resection of the tumor to avoid injury to this critical artery. METHODS: After IRB approval (H-31712), three patients, from 2008 to 2011, with lower posterior mediastinal tumors were identified. Their charts were reviewed for information concerning preoperative imaging, operative details, and postoperative neurologic complications. The literature regarding imaging of the AKA, cases of injury in pediatric patients, and recommendations for treatment after its injury were reviewed. RESULTS: One patient, who did not have preoperative spinal angiography, developed transient paresis lasting 6 weeks after posterior mediastinal tumor resection. Two patients underwent preoperative spinal angiography with successful localization of the AKA. In both cases, the patients subsequently underwent posterior mediastinal tumor resection without injury to the artery and without postoperative neurologic sequelae. CONCLUSIONS: Preoperative spinal angiography may serve as a useful adjunct in the evaluation of children with inferior posterior mediastinal tumors in order to delineate the relationship of the artery of Adamkiewicz to the tumor for the purpose of guiding surgical resection.

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.

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.

Spinal cord protective strategies during descending and thoracoabdominal aortic aneurysm repair in the modern era: the role of intrathecal papaverine.

OBJECTIVES: An array of neuroprotective strategies has evolved to limit spinal cord injury during descending thoracic aneurysm and thoracoabdominal aortic aneurysm repair. This study prospectively assessed the neuroprotective impact of intrathecal papaverine added to other techniques in aortic aneurysm repairs. METHODS: From January 2002 to January 2010, 398 consecutive patients underwent descending thoracic aneurysm and thoracoabdominal aortic aneurysm repairs at Cleveland Clinic, 68 under hypothermic circulatory arrest. We focused on the remaining 330, in whom a combination of neuroprotective adjuncts was used intraoperatively to mitigate spinal cord ischemia. These included distal aortic perfusion with moderate hypothermia, cerebrospinal fluid drainage, and intrathecal papaverine. Two patient groups were discriminated according to whether intrathecal papaverine was (n = 250) or was not (n = 80) administered. Postoperative outcomes were analyzed from a prospectively maintained clinical database. RESULTS: Preoperative patient characteristics and comorbidities were similar between groups. Extent of aortic disease was also similar: descending thoracic aneurysm (34% with papaverine vs 28%) and Crawford types I (25% vs 34%), II (27% vs 24%), III (13% vs 13%), and IV (2% vs 2.5%). Groups had similar in-hospital mortality (6.4% vs 11%; P = .11) and permanent stroke (4.4% vs 7.5%; P = .3). Permanent paraplegia (3.6% vs 7.5%; P = .01) and paraparesis (1.6% vs 6.3%; P = .01) were significantly lower in the intrathecal papaverine group. CONCLUSIONS: Adding intrathecal papaverine to the neuroprotective protocol for descending thoracic aneurysm and thoracoabdominal aortic aneurysm repairs may enhance spinal cord perfusion and provide additional spinal cord protection.

[Progressive paraplegia in a somnolent child]. / Progredienter Querschnitt bei einem somnolenten Kind.

A somnolent small girl with septic symptoms and a progressive paraplegia was initially treated as having meningitis with complications. Subsequently it was discovered through magnetic resonance imaging (MRI) that she was suffering from spinal epidural empyema due to a staphylococcal superinfection on the basis of tuberculous vertebral osteomyelitis. Lacking surgical facilities therapy was carried out by the anesthesia department using multilevel epidural punctures and drainage. This article discusses the agreement of MRI findings with the interventional findings and the clinical features and shows the leading diagnostic role of MRI throughout the clinical course.

Current strategies for spinal cord protection during thoracic and thoracoabdominal aortic aneurysm repair.

Surgery for thoracoabdominal aortic aneurysms remains challenging, with high mortality and morbidity rates despite overall improvements in the outcome of aortic surgery. Paraplegia and paraparesis remain devastating complications that severely restrict the chance of survival as well as the postoperative quality of life. Preventive measures vary considerably because the causes of spinal cord insufficiency are multifactorial. Here, we review measures to prevent paraplegia/paraparesis arising after surgery for thoracic and thoracoabdominal aortic aneurysms.

Fighting spinal cord complication during surgery for thoracoabdominal aortic disease.

Paraplegia or paraparesis after otherwise successful thoracic or thoracoabdominal aortic reconstruction is a devastating complication for both patient and physician. Various strategies have been developed to minimize the incidence of neurological complications after aortic surgery. The incidence of spinal cord ischemia and subsequent neurological complications has been correlated with (1) the duration and severity of ischemia, (2) failure to establish a spinal cord blood supply, and (3) reperfusion injury. Preoperative identification of the arteria radicularis magna, the artery of Adamkiewicz, facilitates identification of critical intercostal vessels for reimplantation, resulting in reestablishing spinal cord blood flow. Techniques for monitoring spinal cord function using evoked potentials have been developed, and surgical techniques have evolved to reduce the duration of ischemia. Furthermore, sequentially sacrificing all the intercostal arteries while maintaining collateral circulation to the cord has produced good outcomes. The severity of ischemia can be minimized by using cerebrospinal fluid drainage, hypothermia, distal bypass, managing the blood pressure, and adjunctive pharmacological therapy. Reperfusion injury can be reduced with the use of antioxidant therapy. Recent advances in endovascular stentgrafting have reduced the incidence of postoperative spinal complications, especially among high-risk patients.

Evolution of operative strategies in open thoracoabdominal aneurysm repair.

OBJECTIVE: During a 24-year interval, we managed >90% of thoracoabdominal aortic aneurysm (TAA) repairs with a clamp-and-sew (clamp/sew) approach supplemented with protective adjuncts, including renal hypothermia and epidural cooling with aggressive intercostal reconstruction for spinal cord protection. A finite paraplegia rate led to operative modifications using distal aortic perfusion (DAP) through atriofemoral bypass to support cord collateral circulation and selective intercostal reconstruction based on motor evoked potential (MEP) monitoring. This study evaluated the effect of DAP/MEP on perioperative outcomes. METHODS: Consecutive patients undergoing repair of nonruptured Crawford extent I-III TAA using DAP/MEP were compared with propensity-matched patients treated with the clamp/sew technique. Outcomes included 30-day mortality and paraplegia. RESULTS: There were 52 patients in the DAP cohort vs 127 undergoing clamp/sew. The DAP and clamp/sew cohorts differed in age (62.6 vs 69.5 years, P = .0003), presence of Marfan disease (10% vs 2%, P = .01), and chronic dissection (37% vs 8%, P = .001). Operative mortality was low (DAP, 2%; clamp/sew, 5%; P = .38). Postoperative renal insufficiency, although doubled in clamp/sew (17%) vs DAP (8%; P = .10), was not significant. DAP patients had a significantly lower incidence of intercostal reconstruction than the clamp/sew group (10% vs 34%, P < .0001), yet there was no paraplegia in the DAP cohort vs 5% in clamp/sew (P = .11). The composite death/paraplegia rate was decreased with DAP at 1 of 52 (2%) vs clamp/sew at 11 of 127 (9%; P = .01). Paraparesis with complete recovery occurred in 5 of 52 (10%) of the DAP group. CONCLUSIONS: Elective TAA repair was accomplished with a low mortality in the DAP and clamp/sew cohorts. The use of MEP in the DAP cohort (despite a higher spinal cord ischemic risk due to the number of chronic dissection patients) decreased the need for intercostal reconstruction, with no paraplegia to date. DAP with MEP is the preferred operative strategy for extent I to III TAA repair.

Sodium 4-phenylbutyrate protects against spinal cord ischemia by inhibition of endoplasmic reticulum stress.

OBJECTIVE: Delayed paraplegia after operation on the thoracoabdominal aorta is considered to be related to vulnerability of motor neurons to ischemia. Previous studies have demonstrated the relationship between neuronal vulnerability and endoplasmic reticulum (ER) stress after transient ischemia in the spinal cord. The aim of this study was to investigate whether sodium 4-phenylbutyrate (PBA), a chemical chaperone that reduces the load of mutant or unfolded proteins retained in the ER during cellular stress, can protect against ischemic spinal cord damage. METHODS: Spinal cord ischemia was induced in rabbits by direct aortic cross-clamping (below the renal artery and above the bifurcation) for 15 minutes at normothermia. Group A (n = 6) was a sham operation control group. In group B (n = 6) and group C (n = 6), vehicle or 15 mg/kg/h of sodium 4-PBA was infused intravenously, respectively, from 30 minutes before the induction of ischemia until 30 minutes after reperfusion. Neurologic function was assessed at 8 hours, and 2 and 7 days after reperfusion with a Tarlov score. Histologic changes were studied with hematoxylin-eosin staining. Immunohistochemistry analysis for ER stress-related molecules, including caspase12 and GRP78 were examined. RESULTS: The mean Tarlov scores were 4.0 in every group at 8 hours, but were 4.0, 2.5, and 3.9 at 2 days; and 4.0, 0.7, and 4.0 at 7 days in groups A, B, and C, respectively. The numbers of intact motor neurons at 7 days after reperfusion were 47.4, 21.5, and 44.9 in groups A, B, and C, respectively. There was no significant difference in terms of viable neurons between groups A and C. Caspase12 and GRP78 immunoreactivities were induced in motor neurons in group B, whereas they were not observed in groups A and C. CONCLUSION: Reduction in ER stress-induced spinal cord injury was achieved by the administration of 4-PBA. 4-PBA may be a strong candidate for use as a therapeutic agent in the treatment of ischemic spinal cord injury.