Acute Paraplegia Result from Spinal Ischemia Nine Years After Hybrid Total Arch Repair with Frozen Elephant Trunk: A Case Report.

Spinal cord ischemia due to decreased cord perfusion is a devastating complication in patients with thoracoabdominal dissection following frozen elephant trunk (FET) repair surgery. However, rare occurrence of spinal cord ischemia leading to paraplegia after long-term follow-up of FET repair has been reported. Here, we describe a case of spinal cord ischemia resulting in paraplegia nine years after hybrid total arch repair with FET. Cerebrospinal fluid drainage and serial treatment were utilized to decrease intraspinal pressure and increase blood flow to the spinal cord. Three months after the onset of paraplegia and with treatment and rehabilitation, the patient recovered to walk.

Medullary ischemia after endovascular procedure of infrarenal aorta in a patient with dual anticoagulant and antiplatelet therapy: a case report.

BACKGROUND: Medullary ischemia secondary to surgical procedures of the infrarenal aorta is an infrequent and mostly devastating complication of this procedure, and its nonspecific clinical presentation makes it difficult to promptly diagnose. Prevention measures for this complication are not yet clear; therefore, the need for anticoagulant and/or antiplatelet therapy is discussed. CASE PRESENTATION: This paper reports a case of a 69-year-old Hispanic man presenting with sudden pain and signs of ischemia on his left lower extremity 8 weeks after endovascular repair with endoprosthesis of an infrarenal aorta and left iliac aneurysm. The patient was admitted to the emergency room, where an extensive arterial thrombosis compromising the right iliac and femoral arteries was diagnosed. Dual anticoagulation and antiplatelet therapies were initiated, and therapeutic ranges were achieved. Nonetheless, the patient presented medullary ischemia by microembolization diagnosed by contrast-enhanced magnetic resonance imaging, with unsatisfactory evolution of an intracranial hemorrhagic event without documented excessive anticoagulation. The patient developed permanent pure motor deficit of his lower extremities, absence of sphincter control, and mild cognitive impairment. CONCLUSIONS: This is a complex and extremely rare case. It is important to continue with clinical investigations that give more clarity about the onset of anticoagulation, antiplatelet therapy, and management of dual schemes to decrease the risk of complications in this type of surgical procedure.

Acute administration of oestradiol or progesterone in a spinal cord ischaemia-reperfusion model in rats.

OBJECTIVES: Despite research into protective pharmacological adjuncts, paraplegia persists as a dreaded complication after thoracic and thoracoabdominal aortic interventions. Reports on gender-related neurological outcomes after ischaemic and traumatic brain injuries have led to increased interest in hormonal neuroprotective effects and have generated other studies seeking to prove the neuroprotective effects of the therapeutic administration of 17ß-oestradiol and of progesterone. We hypothesised that acute administration of oestradiol or progesterone would prevent or attenuate spinal cord ischaemic injury induced by occlusion of the descending thoracic aorta. METHODS: Male rats were divided into groups receiving 280 µg/kg of 17ß-oestradiol or 4 mg/kg of progesterone or vehicle 30 min before transitory endovascular occlusion of the proximal descending thoracic aorta for 12 min. Hindlimb motor function was assessed by a functional grading scale (that of Basso, Beattie and Bresnahan) for 14 days after reperfusion. On the 14th day, a segment of the thoracolumbar spinal cord was harvested and prepared for histological and immunohistochemical analyses. RESULTS: There was significant impairment of the motor function of the hindlimb in the 3 study groups, with partial improvement noticed over time, but no difference was detected between the groups. On Day 1 of assessment, the 17ß-oestradiol group had a functional score of 9.8 (0.0-16.5); the progesterone group, a score of 0.0 (0-17.1) and the control group, a score of 6.5 (0-16.9); on the 14th day, the 17ß-oestradiol group had a functional score of 18.0 (4.4-19.4); the progesterone group had a score of 7.5 (0-18.5) and the control group had a score of 17.0 (0-19.9). Analysis of the grey matter showed that the number of viable neurons per section was not different between the study groups on the 14th day. Immunostaining of the spinal cord grey matter was also similar among the 3 groups. CONCLUSIONS: Acute administration of oestradiol or of progesterone 30 min before transitory occlusion of the proximal descending thoracic aorta of male rats could not prevent or attenuate spinal cord ischaemic injury based on an analysis of functional and histological outcomes.

Optical monitoring and detection of spinal cord ischemia.

Spinal cord ischemia can lead to paralysis or paraparesis, but if detected early it may be amenable to treatment. Current methods use evoked potentials for detection of spinal cord ischemia, a decades old technology whose warning signs are indirect and significantly delayed from the onset of ischemia. Here we introduce and demonstrate a prototype fiber optic device that directly measures spinal cord blood flow and oxygenation. This technical advance in neurological monitoring promises a new standard of care for detection of spinal cord ischemia and the opportunity for early intervention. We demonstrate the probe in an adult Dorset sheep model. Both open and percutaneous approaches were evaluated during pharmacologic, physiological, and mechanical interventions designed to induce variations in spinal cord blood flow and oxygenation. The induced variations were rapidly and reproducibly detected, demonstrating direct measurement of spinal cord ischemia in real-time. In the future, this form of hemodynamic spinal cord diagnosis could significantly improve monitoring and management in a broad range of patients, including those undergoing thoracic and abdominal aortic revascularization, spine stabilization procedures for scoliosis and trauma, spinal cord tumor resection, and those requiring management of spinal cord injury in intensive care settings.

Neuroprotective effects of diltiazem in rabbits with occluded aorta

OBJECTIVE: In the present study, we aimed to determine the protective effect of the perfusion of the distal aorta with diltiazem and ringer lactate solution on the spinal cord. METHODS: Twenty-seven New Zealand rabbits were used in which spinal cord ischemia was provided by occlusion of the aorta for thirty minutes. Experimental animals were divided into four groups: group A (n=4), the sham operation group; group B (n=8) in which intraaortic balloon occlusion alone was applied; group C (n=7), ringer lactate group in which ringer lactate was perfused into distal aorta at a rate of 40 ml/kg, hr, following intraaortic balloon occlusion; group D (n=8) diltiazem group in which diltiazem 40 mg/kg, hr, in Ringer lactate was perfused into distal aorta following intraaortic balloon occlusion. Motor function of hind limbs was evaluated by Tarlov's scoring system. After observation, spinal cords were removed for histopathological evaluation. RESULTS: The degree of histopathological injury was well correlated with neurological function. The most severe histopathological injury and neurological dysfunction occurred in group B, followed by group C, D and A respectively. No injury or neurological dysfunction occurred in the sham group. CONCLUSIONS: The protective effect of diltiazem on both histopathological injury and neurological function was significant in comparison with control groups.

OBJETIVO: O objetivo do presente trabalho é determinar o efeito protetor da perfusão na aorta distal com diltiazem e solução de Ringer lactato na medula espinal. MÉTODOS: Foram usados 27 coelhos da raça New-Zeland, nos quais se provocou isquemia da medula espinal por meio de oclusão da aorta durante 30 minutos. Os animais experimentais foram divididos em quatro grupos: grupo A (n=4), o grupo de cirurgia simulada (pseudocirurgia); o grupo B (n=8) no qual se aplicou somente a oclusão do balão intraaórtico; grupo C (n=7), o grupo do Ringer lactato, no qual a solução de Ringer lactato foi perfundida na aorta distal após oclusão do balão intra-aórtico; grupo D (n=8), grupo do dialtiazem, no qual 40 mg/kg/h de diltiazem, em solução de Ringer lactato, foram perfundidas na aorta distal após oclusão do balão intra-aórtico. A função motora dos membros posteriores foi avaliada pelo sistema de escore de Tarlov. Após observação, as medulas espinais foram removidas para avaliação histopatológica. RESULTADOS: O grau de lesão histopatologica estava bem correlacionado com a função neurológica. Lesões histopatológicas e disfunções neurológicas mais graves ocorreram no grupo B, seguido pelos grupos C, D e A, respectivamente. Não ocorreu nenhuma lesão ou disfunção neurológica no grupo de cirurgia simulada. CONCLUSÕES: O efeito protetor do diltiazem na lesão histopatológica e na função neurológica foi significativo em comparação com os grupos-controle.

Ischemic preconditioning and spinal cord function monitoring in the descending thoracic aorta approach.

OBJECTIVES: To evaluate the effectiveness of acute ischemic preconditioning (IP), based on somatosensory evoked potentials (SSEP) monitoring, as a method of spinal cord protection and to asses SSEP importance in spinal cord neuromonitoring. METHODS: Twenty-eight dogs were submitted to spinal cord ischemic injury attained by descending thoracic aorta cross-clamping. In the C45 group, the aortic cross-clamping time was 45 min (n=7); in the IP45 group, the dogs were submitted to IP before the aortic cross-clamping for 45 min (n=7). In the C60 group, the dogs were submitted to 60 min of aortic cross-clamping (n=7), as in the IP60 group that was previously submitted to IP. The IP cycles were determined based on SSEP changes. RESULTS: Tarlov scores of the IP groups were significantly better than those of the controls (p = 0.005). Paraplegia was observed in 3 dogs from C45 and in 6 from C60 group, although all dogs from IP45 group were neurologically normal, as 4 dogs from IP60. There was a significant correlation between SSEP recovery time until one hour of aortic reperfusion and the neurological status (p = 0.011), showing sensitivity of 75% and specificity of 83%. CONCLUSION: Repetitive acute IP based on SSEP is a protection factor during spinal cord ischemia, decreasing paraplegia incidence. SSEP monitoring seems to be a good neurological injury assessment method during surgical procedures that involve spinal cord ischemia.

Pré-condicionamento isquêmico e monitorização da função medular na abordagem da aorta torácica descendente / Ischemic preconditioning and spinal cord function monitoring in the descending thoracic aorta approach

OBJETIVOS: Avaliar a eficácia do pré-condicionamento isquêmico (PI) agudo, guiado por potenciais evocados somatossensoriais (PESS), como método de proteção medular em cães e analisar o valor dos PESS na monitorização da função medular. MÉTODOS: Foram utilizados 28 cães submetidos à isquemia medular obtida pelo pinçamento da aorta torácica descendente. No grupo C45, o tempo de oclusão aórtica foi de 45 min (n = 7); no grupo PI45, os cães foram submetidos ao PI antes do pinçamento aórtico por 45 min (n = 7). No grupo C60, os cães foram submetidos a 60 min de oclusão aórtica (n = 7) e no grupo PI60, os cães foram submetidos ao PI, seguido pelo pinçamento aórtico por 60 min. Os ciclos de PI foram determinados pelas alterações dos PESS. RESULTADOS: Os índices de Tarlov dos grupos pré-condicionados foram significativamente melhores que os dos grupos de controle (p = 0,005). Observou-se paraplegia em três cães do C45 e em seis do C60, enquanto todos os cães do PI45 permaneceram neurologicamente normais, assim como quatro do grupo PI60. Houve correlação entre o tempo de recuperação dos PESS após a reperfusão aórtica e o estado neurológico pós-operatório (p = 0,011), com sensibilidade e especificidade de 0,75 e 0,83, respectivamente. CONCLUSÃO: O PI agudo repetitivo, baseado na monitorização do PESS, induziu proteção à isquemia medular causada pelo pinçamento aórtico prolongado. A monitorização do PESS parece ser um bom método de detecção precoce do comprometimento isquêmico medular.

OBJECTIVES: To evaluate the effectiveness of acute ischemic preconditioning (IP), based on somatosensory evoked potentials (SSEP) monitoring, as a method of spinal cord protection and to asses SSEP importance in spinal cord neuromonitoring. METHODS: Twenty-eight dogs were submitted to spinal cord ischemic injury attained by descending thoracic aorta cross-clamping. In the C45 group, the aortic cross-clamping time was 45 min (n=7); in the IP45 group, the dogs were submitted to IP before the aortic cross-clamping for 45 min (n=7). In the C60 group, the dogs were submitted to 60 min of aortic cross-clamping (n=7), as in the IP60 group that was previously submitted to IP. The IP cycles were determined based on SSEP changes. RESULTS: Tarlov scores of the IP groups were significantly better than those of the controls (p = 0.005). Paraplegia was observed in 3 dogs from C45 and in 6 from C60 group, although all dogs from IP45 group were neurologically normal, as 4 dogs from IP60. There was a significant correlation between SSEP recovery time until one hour of aortic reperfusion and the neurological status (p = 0.011), showing sensitivity of 75 percent and specificity of 83 percent. CONCLUSION: Repetitive acute IP based on SSEP is a protection factor during spinal cord ischemia, decreasing paraplegia incidence. SSEP monitoring seems to be a good neurological injury assessment method during surgical procedures that involve spinal cord ischemia.

Neuroprotective effects of diltiazem in rabbits with occluded aorta.

OBJECTIVE: In the present study, we aimed to determine the protective effect of the perfusion of the distal aorta with diltiazem and ringer lactate solution on the spinal cord. METHODS: Twenty-seven New Zealand rabbits were used in which spinal cord ischemia was provided by occlusion of the aorta for thirty minutes. Experimental animals were divided into four groups: group A (n=4), the sham operation group; group B (n=8) in which intraaortic balloon occlusion alone was applied; group C (n=7), ringer lactate group in which ringer lactate was perfused into distal aorta at a rate of 40 ml/kg, hr, following intraaortic balloon occlusion; group D (n=8) diltiazem group in which diltiazem 40 mg/kg, hr, in Ringer lactate was perfused into distal aorta following intraaortic balloon occlusion. Motor function of hind limbs was evaluated by Tarlov's scoring system. After observation, spinal cords were removed for histopathological evaluation. RESULTS: The degree of histopathological injury was well correlated with neurological function. The most severe histopathological injury and neurological dysfunction occurred in group B, followed by group C, D and A respectively. No injury or neurological dysfunction occurred in the sham group. CONCLUSIONS: The protective effect of diltiazem on both histopathological injury and neurological function was significant in comparison with control groups.