Diagnosis and treatment strategies for vascular complications after kidney transplantation / 器官移植

With persistent progress in donor-recipient evaluation criteria, organ procurement and preservation regimens and surgical techniques, the incidence of vascular complication after kidney transplantation has been declined, whereas it is still one of the most severe surgical complications of kidney transplantation, which may lead to graft loss and recipient death, and seriously affect the efficacy of kidney transplantation. Therefore, the occurrence, clinical manifestations, diagnosis and treatment strategies of common vascular complications after kidney transplantation, including vascular stenosis, arterial dissection, pseudoaneurysm, vascular rupture and thrombosis were reviewed in this article. In combination with the incidence, diagnosis and treatment of vascular complications after kidney transplantation in the First Affiliated Hospital of Xi'an Jiaotong University, diagnosis and treatment strategies for common vascular complications after kidney transplantation were summarized, aiming to provide reference for clinical diagnosis and treatment of vascular complications after kidney transplantation, lower the incidence of vascular complications, and improve clinical efficacy of kidney transplantation and survival rate of recipients.

Research on inversion method of intravascular blood flow velocity based on convolutional neural network / 生物医学工程学杂志

Blood velocity inversion based on magnetoelectric effect is helpful for the development of daily monitoring of vascular stenosis, but the accuracy of blood velocity inversion and imaging resolution still need to be improved. Therefore, a convolutional neural network (CNN) based inversion imaging method for intravascular blood flow velocity was proposed in this paper. Firstly, unsupervised learning CNN is constructed to extract weight matrix representation information to preprocess voltage data. Then the preprocessing results are input to supervised learning CNN, and the blood flow velocity value is output by nonlinear mapping. Finally, angiographic images are obtained. In this paper, the validity of the proposed method is verified by constructing data set. The results show that the correlation coefficients of blood velocity inversion in vessel location and stenosis test are 0.884 4 and 0.972 1, respectively. The above research shows that the proposed method can effectively reduce the information loss during the inversion process and improve the inversion accuracy and imaging resolution, which is expected to assist clinical diagnosis.

Imaging value of intracranial steno-occlusive disease based on silent MR angiography modified with hybrid-arterial spin labeling / 中华放射学杂志

Objective:To investigate the stability and feasibility of improved silent MRA technique based on hybrid-arterial spin labeling(ASL) for imaging intracranial arterial stenosis.Methods:From September 2019 to May 2020, totally 35 patients with suspected intracranial vascular stenosis in Department of Neurology of Northern Jiangsu People′s Hospital were enrolled in this study. Silent MRA and improved silent MRA based on hybrid-ASL technique were performed respectively. The acquisition noise (noise measurement and subjective score) of two kinds of MRA examination were evaluated respectively. Two neuroradiologists performed image quality scoring and signal-to-noise ratio (SNR) measurement of intracranial arteries (including internal carotid artery, vertebrobasilar artery, anterior cerebral artery, middle cerebral artery, and posterior cerebral artery) in the two kinds of MRA images using a double-blind, completely randomized method. Independent sample t-test was used to compare the image quality and SNR of two kinds of MRA images in each segment. Two experts assessed the degree of stenosis at the site of confirmed intracranial artery stenosis. Kappa test was used to assess interobserver and intermodel agreement. Results:There was no significant difference in acquisition noise between improved silent MRA and silent MRA ( P>0.05). In all five segments measured, the image quality scores of internal carotid artery [(4.40±0.49)scores], anterior cerebral artery[(4.30±0.33)scores] and middle cerebral artery [(4.46±0.34)scores] in improved silent MRA were higher than those in silent MRA images [(4.02±0.43)scores, (4.02±0.31)scores, (4.02±0.31)scores; t=2.825, 2.877, 1.683, all P<0.05)]. The SNR of internal carotid artery (9.11±1.23) and middle cerebral artery (8.77±1.87) in improved silent MRA images was higher than that in silent MRA images (7.83±1.33, 8.06±2.67, respectively; t=11.154, 3.268, both P<0.05). A total of 24 patients (38 lesions) with intracranial vascular stenosis were diagnosed by CTA. Improved silent MRA (Kappa=0.89, 95%CI 0.82-0.95) and silent MRA (Kappa=0.85, 95%CI 0.77-0.92) were highly consistent among observers in evaluating the degree of cerebrovascular stenosis.The results of improved silent MRA were highly consistent with those of CTA (Kappa=0.92, 95%CI 0.87-0.98), and those of silent MRA were highly consistent with those of CTA (Kappa=0.85, 95%CI 0.77-0.92). Conclusions:The improved silent MRA is feasible to improve the imaging quality and signal uniformity through efficient marking based on keeping the low noise features. In the diagnosis of intracranial stenosis and occlusive disease, the stability of improved silent MRA imaging improves the diagnostic efficiency of stenosis to a certain extent.

Professor Gao Li's thoughts on diagnosis and treatment of cerebrovascular stenosis with integrated traditional Chinese and Western medicine / 中国中西医结合急救杂志

With the aging of the population, the incidence of cerebrovascular diseases has increased significantly. In Western medicine, statins, aspirin and antihypertensive drugs are often used to treat mild and moderate cerebrovascular stenosis. For severe cerebrovascular stenosis, interventional technique and drug therapy are often used. In the course of treatment, it is not rare to see the side effects such as hypersensitivity of western medicine and damage of liver function, and it is not rare to see the patients with poor effect of drug therapy alone or short-term restenosis after intravascular stent implantation. Professor Gao Li, in Department of Neurology, Xuanwu Hospital of Capital Medical University, combined the modern medical theory of cerebral vascular stenosis with the theory of traditional Chinese medicine. According to the clinical manifestations, imaging and ultrasonic examination results of patients, cerebral vascular stenosis was divided into three syndrome types, such as phlegm obstruction and blood stasis type (mainly thickening of inner and middle membrane), qi stagnation and fire melting type (mainly plaque) and mixed type (both membrane thickening and plaque). The methods of invigorating spleen and removing dampness, clearing phlegm and removing blood stasis, soothing liver and relieving depression, clearing away heat and resolving phlegm, cooling blood and activating blood circulation, and the combination of two prescriptions were used for treatment of cerebral vascular stenosis, respectively. Meanwhile, the related Western medicine was added at the same time, which achieved better effect.

Analysis of potential predictors of internal jugular vein stenosis and the anatomic position in hemodialysis patients / 中华肾脏病杂志

Objective@#To identify the anatomical positional relation of the internal jugular vein and the common carotid artery, and investigate the predictive factors associated with the stenosis rate of the internal jugular vein after catheterization in hemodialysis patients.@*Methods@#A single-center cross-sectional survey study of 235 patients from the Department of Nephrology, Guangdong Provincial People's Hospital between August 2017 and June 2018 was performed. According to whether received hemodialysis treatment, The patients were divided into dialysis group (n=187) and control group (chronic kidney disease non-dialysis patients, n=48). Clinical data such as age, primary disease, history of deep vein catheterization, catheter indwelling time and dialysis age were collected. The positional relationship between the internal jugular vein and the common carotid artery was examined by Doppler ultrasound. Measure the cross-sectional area of the internal jugular vein in different neck anatomical planes and analyse of the incidence of internal jugular vein stenosis in the dialysis group. Chi-square test was used to compare the differences in the incidence of internal jugular vein stenosis between subgroups of different ages, with or without catheter retention, catheter indwelling time, dialysis age and presence or absence of diabetic nephropathy.@*Results@#Doppler ultrasonography showed that in the 235 patients, there were four types of anatomical relationship between the internal jugular vein and the common carotid artery in the plane of the flat thyroid cartilage and the apex plane of the upper clavicle. The internal jugular vein was located on the lateral, anterolateral, anterior and medial sides of the common carotid artery, accounting for 16.23%, 36.52%, 41.11% and 3.14% respectively. There were significant differences in the anatomical relationship between the internal jugular vein and the common carotid artery between the left and right sides, different anatomical planes and patients of different ages (P<0.05). The rate of internal jugular vein stenosis in 187 hemodialysis patients was 47.1%. The right internal jugular vein stenosis rate was 66.4% and 44.1% in the age<65 years old group (n=128) and age≥65 years old group (n=59), respectively (P=0.004). The rate of internal jugular vein stenosis was 49.0% and 32.8% (P=0.018) in the catheter placement group (n=151) and the catheterless retention group (n=36), respectively. Two variables including age and history of catheterization were included in the logistic regression equation. The results showed that the history of catheterization was a risk factor for internal jugular vein stenosis (OR=1.668, 95% CI 1.083-2.568, P=0.020).@*Conclusions@#There is variability in the anatomical relationship between the internal jugular vein and the common carotid artery. Internal jugular vein stenosis is a common complication after indwelling catheters in hemodialysis patients. The history of internal jugular vein catheterization is a risk factor affecting internal jugular vein stenosis.

Analysis of potential predictors of internal jugular vein stenosis and the anatomic position in hemodialysis patients / 中华肾脏病杂志

Objective To identify the anatomical positional relation of the internal jugular vein and the common carotid artery, and investigate the predictive factors associated with the stenosis rate of the internal jugular vein after catheterization in hemodialysis patients. Methods A single-center cross-sectional survey study of 235 patients from the Department of Nephrology, Guangdong Provincial People's Hospital between August 2017 and June 2018 was performed. According to whether received hemodialysis treatment, The patients were divided into dialysis group (n=187) and control group (chronic kidney disease non-dialysis patients, n=48). Clinical data such as age, primary disease, history of deep vein catheterization, catheter indwelling time and dialysis age were collected. The positional relationship between the internal jugular vein and the common carotid artery was examined by Doppler ultrasound. Measure the cross-sectional area of the internal jugular vein in different neck anatomical planes and analyse of the incidence of internal jugular vein stenosis in the dialysis group. Chi-square test was used to compare the differences in the incidence of internal jugular vein stenosis between subgroups of different ages, with or without catheter retention, catheter indwelling time, dialysis age and presence or absence of diabetic nephropathy. Results Doppler ultrasonography showed that in the 235 patients, there were four types of anatomical relationship between the internal jugular vein and the common carotid artery in the plane of the flat thyroid cartilage and the apex plane of the upper clavicle. The internal jugular vein was located on the lateral, anterolateral, anterior and medial sides of the common carotid artery, accounting for 16.23％, 36.52％, 41.11％ and 3.14％respectively. There were significant differences in the anatomical relationship between the internal jugular vein and the common carotid artery between the left and right sides, different anatomical planes and patients of different ages (P﹤0.05). The rate of internal jugular vein stenosis in 187 hemodialysis patients was 47.1％. The right internal jugular vein stenosis rate was 66.4％and 44.1％in the age﹤65 years old group (n=128) and age≥65 years old group (n=59), respectively (P=0.004). The rate of internal jugular vein stenosis was 49.0％and 32.8％(P=0.018) in the catheter placement group (n=151) and the catheterless retention group (n=36), respectively. Two variables including age and history of catheterization were included in the logistic regression equation. The results showed that the history of catheterization was a risk factor for internal jugular vein stenosis (OR=1.668, 95％ CI 1.083-2.568, P=0.020). Conclusions There is variability in the anatomical relationship between the internal jugular vein and the common carotid artery. Internal jugular vein stenosis is a common complication after indwelling catheters in hemodialysis patients. The history of internal jugular vein catheterization is a risk factor affecting internal jugular vein stenosis.

Clinical study of supra-aortic artery stenting angioplasty via transradial access / 介入放射学杂志

Objective To investigate the safety, reliability and effectiveness of supra - aortic artery stenting angioplasty via transradial access in treating supra-aortic artery occlusion or stenosis. Methods The clinical data of 325 consecutive patients with supra-aortic artery occlusion or stenosis, who were admitted to authors' hospital during the period from January 2012 to January 2016 to receive stenting angioplasty, were retrospectively analyzed. According to patient's own will, the 325 patients were divided into transradial access group (n=52) and transfemoral access group (n=273). The results of the puncturing, the operative results, the duration of operation, the amount of intraoperative blood loss, the postoperative complications, the time of postoperative rest in bed, the average time of hospitalization of both groups were recorded. Results No statistically significant differences in the success rate of puncturing, the success rate of operation and the amount of intraoperative blood loss existed between the two groups (P＞0. 05). In 73. 1％ of patients (38/52) of the transradial access group the duration of operation was ≤30 min, while only in 43. 2％ of patients (118/ 273) of the transfemoral access group the duration of operation was ≤30 min, the difference between the two groups was statistically significant (P＜0. 000 1). After the operation, in transradial access group puncture point bleeding was seen in 8 patients and hematoma at the puncture site in one patient, the complication rate was 17. 3％ (9/52), while in transfemoral access group puncture point bleeding was observed in 23 patients, hematoma at the puncture site in 7 patients, pain of puncture site in one patient, and cerebral hemorrhage in one patient, the total complication rate was 11. 7％ (32/273); but the difference between the two groups was not statistically significant (χ2=1. 236, P=0. 266). Patients in the transradial access group could get out of bed immediately after the operation. No statistically significant difference in the average time of hospitalization existed between the two groups (P＞0. 05). Conclusion In performing endovascular stenting angioplasty for supra-aortic artery occlusion or stenosis, both transradial access and transfemoral access are safe, reliable and effective. Transradial access can be used as a replacement of transfemoral access. (J Intervent Radiol, 2018, 27:207-210)

Clinical study of ECG ischemic grading and target vessel stenosis degree in patients with acute myocardial infarction / 中国综合临床

Objective To study the relationship between ECG ischemic grading and target vessel stenosis degree in patients with acute myocardial infarction ( AMI ) . Methods A total of eighty patients with AMI treated in Beijing Friendship Hospital, Capital Medical University from January 2016 to June 2017 were enrolled in the study, with the onset time<12 h, According to the Birnbaum ECG grading, the patients were divided into the grade two ischemic group( 50 cases) and grade three ischemic group( 30 cases) . CAG diameter visual method was used to compare the target vessels localization and stenosis degrees,the levels of CK?MB,cTnI and pro?BNP,left ventricular end diastolic diameter ( LVEDd) and ejection fraction ( LVEF) were detected, myocardial infarction area ( MIS) was measured by 99mTe?MIBI myocardial perfusion imaging ( SPECT) at 7 d after operation,the incidence of major cardiac adverse events ( MACE) was followed up for 6 months. area of myocardial defect,that is myocardial infarction size(MIS)with SPECT 7d after operation,during the 6 months follow?up,the incidence of major adverse cardiac events ( MACE) . Results The baseline lines of CK?MB,cTnI and pro?BNP and increased ranges ( post intervention?baseline value) in the grade three ischemic group were higher than those of grade two ischemia group,there were statistically significant differences in baseline values:(CK?MB:(56. 7±12. 3) U/L vs. (26. 8±8. 7) U/L,t=12. 326,P<0. 001; increase: (66. 7±13. 5) U/L vs.(35. 6)±6. 9) U/L,t=32. 545,P<0. 001; cTnI: baseline value: (8. 6±2. 2) g/L vs. (4. 5±1. 3) g/L,t=6. 598,P=0. 003;increase:(15. 2±5. 7) g/L vs. (6. 3±2. 5) g/L,t=9. 524,P<0. 001; pro?BNP: baseline value:(356. 7±65. 8) mol/L vs. (254. 5±56. 7) mol/L,t=10. 326,P<0. 001; increase: (658. 4±135. 2) mol/L vs. (356. 2±95. 4) mol/L,t=25. 254,P<0. 001). There was no significant difference in LVEDd and LVEF between groups. (LVEDd:(55. 2±2. 6) mm vs. (54. 8±2. 3) mm,t=0. 263,P=0. 785; LVEF: (42. 5 ±4. 8)％ vs. (43. 3±4. 5)％,t=0. 426,P=0. 659). The occurrence rates of left anterior descending,left main lesions and left main bifurcation lesions in the grade three ischemic group were higher ( 50. 0％ vs. 10. 0％,χ2=16. 000,P<0. 001;16. 7％ vs. 4. 0％,χ2=2. 348,P=0. 125;10. 0％ vs. 4. 0％,χ2=0. 356,P=0. 551),and the circumflex and right coronal and branch lesions proportions took the most part in the grade two ischemic group(10. 0％ vs. 30. 0％,χ2=4. 301,P=0. 038;10. 0％ vs. 40. 0％,χ2=8. 238,P=0. 004;3. 3％ vs. 12. 0％,χ2=0. 845,P=0. 358);the proportions of target lesion number>1 and 100％ stenosis in the grade three ischemic group were significantly than those in the in the grade two ischemic group ( target lesion number>1:36. 7％ ( 11/30) vs. 14％ (7/50),P=0. 019;100％ stenosis:40％ (12/30) vs. 12％ (6/50),P=0. 004),the difference is statistically significant. The MIS value increased significantly in the grade three ischemia group, and the incidence of MACE increased. The difference was statistically significant ( (16. 7±3. 5)％ vs. (10. 5±3. 6)％,t=5. 754,P=0. 019,23. 3％ vs. 6％,χ2=5. 150,P=0. 023) . Conclusion ECG ischemic grading can evaluate the location of AMI target vessel and the degree of stenosis,and it has important clinical value.

Research progress on vascular pharmacologic effects of oleanolic and ursolic acids / 药物评价研究

Ursolic and oleanolic acids antagonize ox-LDL-,C-reactive protein-,non-enzymatic glycation end products-,hyper-glucose-,H2O2-,lipopolysaccharide-induced endothelial cell injury,and their vascular pharmacologic effects are in many ways.Ursolic and oleanolic acids can inhibit the proliferation of vascular smooth muscle cells,and antagonize serum-,ox-LDL-,hyper-glucose-,leptin-induced vascular smooth muscle cell proliferation,thus produce vascular protection and improve vascular function;Ursolic and oleanolic acids can relieve diabetic vascular complication in diabetic mellitus rats,and vascular stenosis induced by carotid balloon catheter injury,and suppress the proliferation of vascular adventitial fibroblasts and prevent vascular stenosis induced by various experimental atherosclerosis models;they can also inhibit the proliferation of vascular endothelial cells,and have a dual action to antagonize inhibiting or promoting proliferation induced by various injurious factions.Thus they have a dual role of regulation in angiogenesis,and suppress angiogenesis of cornea,diabetic retina,and tumor tissues,have effects of vascular relaxation and resistance decrease,and have hypotensive effects in normal and various hypertensive animals.

Research progress in imaging technology of the vascular stenosis evaluation / 国际儿科学杂志

Vascular stenosis can mainly be divided into two types:the congenital vascular stenosis and acquired vascular stenosis.The etiology of congenital vascular stenosis is unclear yet,it usually occurred in different types of congenital cardiovascular and cerebrovascular stenosis.Acqnired vascular stenosis is often caused by athemsclerotic plaque,resulting in the percutaneous brace implantation,or balloon angioplasty.Imaging methods can be helpful in the clinical diagnosis and evaluation of various congenital or acquired vascular stenosis accurately and timely.Currently,imaging technology has developed rapidly and the new imaging technology emerges.This paper briefly reviews the imaging technology progress in evaluating the vascular stenosis.

Intracranial Artery Calcification and Its Clinical Significance

Intracranial arterial calcification (IAC) is an easily identifiable entity on plain head computed tomography scans. Recent studies have found high prevalence rates for IAC worldwide, and this may be associated with ischemic stroke and cognitive decline. Aging, traditional cardiovascular risk factors, and chronic kidney disease have been found to be associated with IAC. The severity of IAC can be assessed using different visual grading scales or various quantitative methods (by measuring volume or intensity). An objective method for assessing IAC using consistent criteria is urgently required to facilitate comparisons between multiple studies involving diverse populations. There is accumulating evidence from clinical studies that IAC could be utilized as an indicator of intracranial atherosclerosis. However, the pathophysiology underlying the potential correlation between IAC and ischemic stroke-through direct arterial stenosis or plaque stability-remains to be determined. More well-designed clinical studies are needed to explore the predictive values of IAC in vascular events and the underlying pathophysiological mechanisms.

Intracranial Artery Calcification and Its Clinical Significance

Intracranial arterial calcification (IAC) is an easily identifiable entity on plain head computed tomography scans. Recent studies have found high prevalence rates for IAC worldwide, and this may be associated with ischemic stroke and cognitive decline. Aging, traditional cardiovascular risk factors, and chronic kidney disease have been found to be associated with IAC. The severity of IAC can be assessed using different visual grading scales or various quantitative methods (by measuring volume or intensity). An objective method for assessing IAC using consistent criteria is urgently required to facilitate comparisons between multiple studies involving diverse populations. There is accumulating evidence from clinical studies that IAC could be utilized as an indicator of intracranial atherosclerosis. However, the pathophysiology underlying the potential correlation between IAC and ischemic stroke-through direct arterial stenosis or plaque stability-remains to be determined. More well-designed clinical studies are needed to explore the predictive values of IAC in vascular events and the underlying pathophysiological mechanisms.

Effect of clopidogrel on neck blood vessel stenosis and plasma fibrinogen in patients with SIP / 中国生化药物杂志

Objective To study effect of clopidogrel on neck blood vessel stenosis and plasma fibrinogen ( FIB ) in patients with stroke in progression(SIP).Methods 80 cases with SIP were selected from March 2014 to March 2015, they were divided into study group and control group according to the random number table method, 40 cases in each group, the control group was received conventional treatment, the study group was given clopidogrel on the basis of conventional treatment, evaluation of neurological function and living ability of patients with Stroke Scale (NIHSS) and daily living ability score ( ADL) , carotid artery stenosis were measured by color Doppler, the levels of FIB and C reactive protein ( hs-CRP) in two groups were also measured, adverse reactions in the two groups were compared.Results Carotid artery, internal carotid artery, external carotid artery diameter before treatment between two groups were no statistical significance,which all increased after treatment, and the study group was wider than the control group, the difference was statistically significant (P <0.05);NIHSS score and ADL score before the treatment between two groups was no statistical significance.NIHSS score and ADL score after treatment between two groups were significant improved, and the study group was better than the control group, the difference was statistically significant (P<0.05); FIB and hs-CRP before the treatment between two groups was no statistical significance, FIB and hs-CRP levels after treatment between two groups were significantly reduced, the study group was significantly lower than the control group, the difference was statistically significant (P<0.05); the adverse reactions of the two groups were not statistically significant.Conclusion Clopidogrel can significantly improve the neurological function, improve the degree of cervical vascular stenosis, reduce the level of FIB for SIP patients in recovery period.

Therapeutic effect of endovascular stenting on TIA caused by vascular stenosis / 心血管康复医学杂志

Objective:To explore therapeutic effect and safety of endovascular stenting on transient ischemic attack (TIA) caused by atherosclerotic vascular stenosis .Methods:A total of 100 patients with TIA caused by vascular ste-nosis in our hospital from Jan 2011 to Feb 2013 were enrolled ,and equally divided into combined treatment group (received endovascular stenting combined medication ) and routine treatment group (received medication treat-ment) .After 12-month treatment ,recurrence rate of TIA ,incidence rate of stroke and vascular stenosis rate before and after treatment were compared between two groups .Results:Compared with before treatment ,there was no significant change in all above-stated indexes after treatment in routine treatment group;were significant reduction in vascular restenosis rate [ (73.31 ± 12.76)% vs .(25.01 ± 5.73)% ] in combined treatment group ,and it signifi-cantly reduced than that of routine treatment group (74.33 ± 12.96)% ,P<0.01 both ;during the 12-month follow-up ,compared with routine treatment group , there were significant reductions in percentages of recurrent TIA (16.0% vs .2.0% ) and cerebral stroke (12.0% vs .0) in combined treatment group ,P<0.05 both Conclusion:En-dovascular stenting can significantly improve clinical therapeutic effect and prognosis in patients with atherosclerotic vascular stenosis ,and is worth clinical extension in some condition .

A Case of Atypical Miller-Fisher Syndrome with Internal Carotid Artery Stenosis / 대한소아신경학회지

Miller-Fisher syndrome is an acute poly-neuropathy typically characterized by the triad of ophthalmoplegia, ataxia, and areflexia. Other poly-neuropathy diseases include Guillain-Barre syndrome and Bickerstaff brainstem encephalitis. However, not all cases of Miller-Fisher syndrome have the typical three symptoms. These diseases have been differentiated by clinical manifestations and anti-GQ1b IgG antibody testing. In Miller-Fisher syndrome, anti-GQ1b IgG antibody is present in over 95% of patients; however, the frequency is not so high in normal subjects or in those with other poly-neuropathy diseases. Infectious illnesses, such as respiratory diseases and gastrointestinal diseases, usually precede Miller-Fisher syndrome. In general, Miller-Fisher syndrome is a self-limiting illness; however, a few cases of Miller-Fisher syndrome progressing to respiratory failure have been reported, particularly in children. In this case, we report abnormal angiographic findings. We report a case of atypical Miller-Fisher syndrome with internal carotid artery stenosis treated with prednisolone.

Serum NO and NOS in Different Kinds of Cerebral Vascular Stenosis / 医学研究杂志

Objective To search for the mechanism of NO and TNOS/iNOS in cerebral vascular stenosis,the changes of these serum factors in different kinds of cerebral vascular stenosis were studied. Methods Biochemistry assays were adopted,to analyze serum NO and TNOS/iNOS in different vascular stenosis group. Results Serum NO contents of ' Mix' (P=0.000) or ' MCA' (P=0.001) significantly increased. INOS activity of ' In' (P=0.004) and ' MCA' (P=0.002) markedly increased. And TNOS activity of ' In' group significantly weakened (P=0.032),but the TNOS activity of ' Mix' (P=0.011) and ' MCA' (P=0.018) group markedly intensified. Conclusion NO and TNOS/ iNOS partly participate in the occurrence mechanism of cerebral vascular stenosis. And the study provided theory basis for studying multiple factors of cerebral vascular stenosis.

Flow Measurement in the Hemodialysis Vascular Conduit for Surveillance of Internal Arteriovenous Fistula: A Trend Analysis

PURPOSE: We have already reported on a new method to calculate the intra-vascular conduit flow rate based on Bernoulli's theory for maintaining surveillance of the arteriovenous fistula (AVF) function. To assess the clinical validity of our methods, we examined a trend analysis on the calculated flow rate in hemodialysis vascular conduits. METHODS: From a total of 27 cases of native AVFs that were at least 3 months after construction, we measured the AVF flow rate (Q(D)) with Doppler ultrasonography first. When Q(D) was below 600 ml/min, a fistulogram was taken. The intra-vascular conduit static pressure (ps) was measured, and the flow rate (Q(a)) was calculated every month with using the mean arterial pressure. The patients with a decreased Q(a) of more than 10% over 3 months were referred for a diagnostic fistulogram. RESULTS: Twenty-seven AVFs were studied after 29.5+/-28.5 (4~120) months of operation. The mean Q(D) was 980.6+/-501.6 (144~2,230) ml/min. In 6 patients who showed a Q(D) less than 600 ml/min, 4 pathologic lesions were found on the diagnostic fistulogram: juxta-anastomosis stenosis (n=3) and a draining venous stenosis (n=1). Three patients who showed a Q(a) decrement were confirmed as having a draining venous stenosis. However, any unpredictable thrombosis with proximal stenosis (n=2) couldn't be detected. CONCLUSION: Q(a) represents the narrowing of the draining vein of an internal AVF. However, arterial or venous narrowing that is proximal to the arterial puncture site couldn't be detected with the calculated intra-conduit flow rate. The development of new methods that can detect proximal vascular stenosis and that can be used in combination with our method is anticipated in the near future.

MR Angiography in Patients with Transient Ischemic Attack

BACKGROUND: Several western studies have found an occurrence of abnormal angiographic findings in 60-80% of patients with carotid artery territory transient ischemic attack(below carotid TIA) and showed that the location of pathology was frequent in extracranial portion of carotid artery. No accurate studies have been accomplished in our country and some racial differences may exist. So we studied the angiographic findings in patients with carotid TIA. METHODS: Thirty two patients with carotid TIA were included, but patients with non-atherosclerotic origin were excluded. MRI and MRA were checked simultaneously in all patients within 7 days after the last TIA. We evaluated the location, type and degree of the angiographic abnormalities and defined clinical factors related to the presence of vascular lesions. The criteria of significant abnormal findings were stenosis of more than 50%, ulceration or irregularity of carotid territory arteries contralateral to clinical symptoms. RESULTS: Thirteen(40.6%) patients showed significant angiographic abnormalities related with the symptoms of TIA, and M1 portion of middle cerebral artery was the most frequent site, in 7 of 13 patients(53%). Patients with TIAs lasted less than 30 min.(P=0.011) and with TIAs occurred more than 4 times a day(P=0.029), had more frequent angiographic abnormalities. But there were no significant differences according to the presence of related acute cerebral infarction, gender and risk factors of stroke. CONCLUSIONS: In our study, the prevalence of angiographic abnormality and the location of vascular lesion were concordant with the Japanese studies but quite different with the western studies, and we suggest that this may be due to differences in dietary life and race.

Role of Intraoperative Microvascular Doppler Sonography in the Surgery of Cerebral Aneurysm

The authors measured flow velocity of intracranial arteries to venrify the patency of the parent arteries and branches after clip placement during aneurysm surgery. Before the clinical study, experimental sonographic recording was done with a feline aorta. The patency was evaluated by recording the flow velocity and pulse waveform using intraoperative microvascular Doppler sonography. The results of the clinical study were summarized as follows: (1) The patency of the parent artery can be proved. (2) The complete clipping of aneurysmal sac can be confirmed. (3) Vasospasm or narrowing of the arterial caliber can be detected. (4) Severe arteriosclerosis may mimic decreased flow velocity. It is suggested that the use of intraoperative microvascular Doppler sonography is an atraumatic and reliable method of testing the optimal clipping of the aneurysm and patency of the parent artery.