Revision Superficial Temporal Artery-Middle Cerebral Artery Bypass Surgery for Recurrent Acute Ischemic Stroke Due to Delayed Occlusion of the Bypass Graft

Intravenous thrombolysis (IVT) and endovascular treatment (EVT) are currently the main treatments for reperfusion in acute ischemic stroke. Although the EVT recanalization rate has increased, unsuccessful recanalization is still observed in 10-30% cases. Superficial temporal artery-middle cerebral artery (STA-MCA) bypass is considered a rescue therapy in such cases, but in most centers it is not usually performed for acute ischemic stroke. Graft occlusion is rare following STA-MCA bypass, but it might lead to recurrent ischemic stroke. We hereby report on a patient with right MCA infarction and in whom EVT failed due to complete proximal internal carotid artery occlusion. He underwent an emergency STA-MCA bypass, resulting in a full recovery of his motor weakness. However, six months later, the patient experienced recurrent acute ischemic stroke due to bypass graft occlusion. His EVT failed again but revision bypass surgery, using STA remnant branch, was successful with full motor weakness recovery. We recommend a revision bypass surgery as a feasible therapeutic option for recurrent cerebral infarction caused by delayed STA graft occlusion.

Comparison of long-term results of above-the-knee femoro-popliteal bypass with autogenous vein and polytetrafluoroethylene grafts

PURPOSE: To analyze the long-term results of above-the-knee femoro-popliteal bypass (ATKFPB) with vein grafts compared with polytetrafluoroethylene (PTFE) grafts. METHODS: A database of patients with chronic atherosclerotic occlusive disease who underwent ATKFPB was retrospectively reviewed. Characteristics of patient and arterial lesion, and follow-up results were compared between vein grafts and PTFE grafts. Graft patency was determined by periodic examinations of duplex ultrasonography or CT angiograms. Graft patency and limb salvage rates were calculated using the Kaplan-Meier method. RESULTS: In total, 253 ATKFPBs (107 vein grafts; 146 PTFE grafts; critical limb ischemia, 32%) were performed on 228 patients (mean age, 68.5 years; male, 87.7%). No significant differences were observed between the two groups with respect to demographic characteristics, characteristics of arterial lesions, or distal runoff score. During the mean follow-up period of 41 months (range, 1-122 months), 14.5% patients died, and 94% of all limbs were available for follow-up. The primary patency rates were not significantly different between the two groups at 10 years after treatment (75% vs. 42%, P = 0.330). However, the primary-assisted patency rates (88% vs. 42%, P = 0.003) and secondary patency rates (91% vs. 49%, P = 0.013) were significantly higher in the vein grafts compared with the PTFE grafts. Graft occlusion developed more often in the PTFE grafts (5.6% vs. 20.5%, P = 0.001). When graft occlusion occurred, acute limb ischemia was significantly more frequent in the PTFE grafts than in the vein grafts (0% vs. 53%, P = 0.027). CONCLUSION: After ATKFPB, autologous vein grafts showed significantly better long-term results compared with PTFE grafts.

Estenose do enxerto de veia safena magna reversa em revascularização arterial infrainguinal / Stenosis of reverse great saphenous vein graft in infrainguinal arterial revascularization

OBJETIVO: Avaliar a prevalência de estenose hemodinamicamente significativa na revascularização infrainguinal realizada com a veia safena magna reversa. MÉTODOS: No período compreendido entre março de 2008 e março de 2009, foram realizadas 56 revascularizações infrainguinais com a veia safena magna reversa em 56 pacientes, dos quais 32 foram avaliados com ultrassonografia vascular no 30º dia de pós- operatório. Foi analisada a prevalência de estenoses significativas nos enxertos e sua relação com as características clínico-cirúrgicas dos pacientes. Os parâmetros avaliados foram a localização das estenoses ao longo do enxerto, fatores de risco associados e a relação existente entre a ultrassonografia vascular e o índice tornozelo-braço no diagnóstico de estenoses. RESULTADOS: Houve prevalência de 48,4 por cento de estenoses significativas nos enxertos avaliados, com 19,4 por cento de estenoses graves e 29 por cento de estenoses leve a moderada. Não foram encontradas associações significativas entre sexo, diabetes mellitus, hipertensão arterial, hipercolesterolemia, diâmetro do enxerto, localização da anastomose distal, composição do enxerto e a constatação de estenoses significativas. Observou-se fraca correlação entre os métodos no diagnóstico das estenoses em geral (K = 0,30; IC95 por cento 0,232-0,473; p = 0,018), mas razoável concordância no diagnóstico das estenoses graves (K = 0,75; IC95 por cento 0,655-0,811; p = 0,0001). CONCLUSÃO: Este estudo demonstrou elevada prevalência de estenoses no 30º dia do pós-operatório, com localização predominante na metade proximal do enxerto. O índice tornozelo-braço e a ultrassonografia vascular apresentaram concordância, sobretudo no diagnóstico das estenoses graves, mas o índice tornozelo-braço, isoladamente, mostrou-se insuficiente na vigilância dos enxertos de veia safena magna reversa.

OBJECTIVE: The aim of this study was to evaluate the prevalence of hemodynamically significant infrainguinal bypasses stenosis using reverse great saphenous vein graft. METHODS: From March of 2008 to March of 2009, 56 infrainguinal bypasses were performed with reverse great saphenous vein graft in 56 patients. On the 30th post-operative day, 32 out of 56 patients were submitted to vascular ultrasonography. The prevalence of significant graft stenosis was determined. In addition, the diagnosis of stenosis was related to the clinical and surgical characteristics of the patients. The variables analyzed at the moment of diagnosis were the localization of the graft stenosis, the risk factors associated with stenosis and the association of vascular ultrasonography findings with ankle brachial pressure index (ABI). RESULTS: The overall prevalence of significant graft stenosis was 48.4 percent. Out of the total number of observed stenosis, 19.4 percent were considered severe, and 29 percent mild or moderate. There was no significant association between the presence of significant stenosis and the following variables: gender, diabetes, hypertension, smoking, hipercholesterolemia, graft diameter, site of the distal anastomosis, and graft composition. There was a weak agreement between ABI and vascular ultrasonography in detecting stenosis in general (K = 0.30; CL95 percent 0.232 - 0.473; p = 0.018). However, there was a substantial agreement in detecting severe stenosis (K = 0.75; CL95 percent 0.655 - 0.811; p = 0.0001). CONCLUSION: There was a high prevalence of stenosis on the 30th post-operative day, mostly localized in the proximal half of the vein graft. There was no significant association of stenosis with clinical and surgical factors analyzed. ABI and vascular ultrasonography had weak agreement with the diagnosis of stenosis in general and an important agreement for the diagnosis of severe stenosis.

Role of vascular endothelial growth factor in vein sheath prevention of arterial bypass graft stricture / 第二军医大学学报

Objective:To study the role of vascular endothelial growth factor(VEGF) in vein sheath prevention of arterial bypass graft stricture and the efficacies of vein sheath of different diameters. Methods: The vein grafts and their specimens were obtained via animal experiment of sheath intervention. Immunohistochemistry method was used to examine the expression of VEGF and proliferating cell nuclear antigen (PCNA) and the status of nutrient vessel in the specimens, so as to investigate the function of VEGF. Results: Compared with the control group, the vein sheath intervention group had significantly lower VEGF content in the media (P<0.05) and higher content in the adventitia (P<0.05); it also had lower PCNA content in the media (P<0.05) and increased blood vessel density in the adventitia (P<0.05). Conclusion: Vein sheath can effectively increase the distribution of VEGF in the adventitia and decrease its distribution in the media and intima, thus promoting the growth of nutrient blood vessels and decreasing media hyperplasia and re-stenosis.