Coronary artery fractional flow reserve (FFR) is a critical physiological indicator for assessment of impaired blood flow caused by coronary artery stenosis. The wire-based invasive measurement of blood flow pressure gradient across stenosis is the gold standard for clinical measurement of FFR. However, it has the risk of vascular injury and requires the use of vasodilators, increasing the time and overall cost of interventional examination. Coronary imaging is playing an important role in clinical diagnosis of stenotic lesions, evaluation of severity of lesions, and planning of therapies. In recent years, the computation of FFR based on the physiological information of blood flow obtained from routinely collected coronary image data has become a research focus in this field. This technique reduces the cost of physiological assessment of coronary lesions and the use of pressure wires. It is beneficial to strengthen the physiological guidance in interventional therapy. In order to better understand this emerging technique, this paper highlights its implementation principle and diagnostic performance, analyzes practical problems and current challenges in clinical applications, and discusses possible future development.
ObjectiveTo observe the changes of vessel densities (VD) in the macula and optic disc and its correlation with axial length (AL) in pathological myopia (PM). MethodsA retrospective clinical study. A total of 171 eyes from 171 patients admitted to Department of Ophthalmology of Jinshan Hospital of Fudan University from June 2019 to December 2019 were included in this study. Among them, there were 72 males and 99 females; age was 35.0±10.8 years old. The patients were divided into PM group, high myopia (HM) group and non-HM group, 51 cases with 51 eyes, 70 cases with 70 eyes, and 50 cases with 50 eyes, respectively. Optical coherence tomography angiography was used to scan the macular and optic disc areas of all the examined eyes in the range of 6 mm×6 mm. According to the early treatment of diabetic retinopathy study, the 6 mm macular and optic disc scan range was centered on the macular fovea and optic disc, respectively, then divided into two concentric circles with diameters of 1 mm of central area, an annulus between 1-3 mm circles of paracentral area. The paracentral area was divided into superior, inferior, nasal, temporal four quadrants by 2 radiation lines. The VD of superficial capillary plexus (SCP), deep capillary plexus (DCP), outer retina, and choriocapillaris layer were calculated in the central, superior, inferior, nasal, and temporal areas, respectively. The VD of PM, HM and non-HM groups were compared. The variance analysis was used to compare the VD among the three groups; Pearson’s correlation was used to assess the correlation between VD and AL. ResultsThe perifoveal VD of the SCP, outer retina and choriocapillaris layers were all lower in the PM than those of HM and non-HM group, and the differences were statistically significant (P＜0.05). The VD of DCP macular central was higher in the PM than in the HM group, and the difference was statistically significant (P=0.020). In the optic disc, the VD were lower in the PM group than in the non-HM group except for the area of DCP superior, inferior, temporal, outer retinal center, and the differences were statistically significant (P＜0.05). The results of correlation analysis showed that the VD in the DCP macular central, ONH superior and the choriocapillaris ONH central were not correlated with AL (P=0.647, 0.688, 0.146), and the other VDs were negatively correlated with AL (P＜0.05). ConclusionCompared with HM and non-HM groups, the majority of VDs in macular and ONH are lower in participants with PM.
Objective To study the changes of blood flow of the already-compressed cauda equina under dynamic burden, high frequency stimulation (HFS) and increased additional compression, and to clarify the mechanism of neurogenic intermittent claudication. Methods Thirty SD rats were divided into 5 groups, 6 in each. All groups were operated with laminectomy of the fifth lumbar verfebra. One hour after the measurement of blood flow,in 4experimental groups, the silicon sheets were inserted into the spinal canal of L4 and L6 to cause double level compression of cauda equina by 30%. Two hours after onset of compression, no dynamic burden was introduced to the subjects of the experimental group 1. Only HFS was introduced to the subjects of the experimental group 2 for 6 minutes. Both HFS and increased additional compression were introduced to the subjects of the experimental group 3 for 6 minutes. While only increased additional compression was introduced to the subjects of the experimental group 4 for 6 minutes. The subjects of control group only underwent laminectomy of the fifth lumbar vertebra and HFS 6 minutes. The blood flow of cauda equina was measured with laser Doppler flowmeter. Results In the first 2 hours, there was no significant change of cauda equina blood flow in the control group. During the time of HFS, the blood flow increased significantly to 186.4%±31.5% of initial value (Plt;0.05). In the experimental group 1, there was no blood flow change during the period of dynamic burden（110.4％±7.5％，Pgt;0.05）. After introduction of dynamic burden, there was no blood flow changes in the experimental group 2 (111.6％±17.6％，Pgt;0.05). The blood flow in the experimental group 3 decreased to 65.3%±10.7% of initial value (Plt;0.05); and the blood flow in the experimental group 4 decreased to 60.1%±9.2% of initial value (Plt;0.01). There was no significant difference between the experimental groups 3 and 4 (Pgt;0.05). Conclusion The results above show that during the period of increased impulse transmission, double level compression of cauda equina may limit the increase of blood flow, which maycause relative ischemia. If there is increased additional compression along with increased impulse transmission, the blood flow will decrease significantly, which will cause absolute ischemia.
To evaluate the possibil ity of collateral outflow tract of arterial sclerosis obstruction （ASO）and the prospect of cl inical appl ication. Methods The red emulsion was infused into the arteries of the above knee amputation of 10 fresh specimens. Then the pathological changes of the anterior tibial artery, posterior tibial artery and the popl iteal artery, and the contribution of these bole artery branch were observed. From September 2005 to April 2007, 5 patients with ASO were treated, unilateral lower l imb was involved in all cases. There were 3 males and 2 females, aged 68-81 years. The arteriography and Color Doppler ultrasound of lower l imbs showed that the femoral artery and the popl itealartery and the branches had no development. The exploratory operation on the popl iteal artery and the branches was carried out. Results The walls of the anterior tibial artery, posterior tibial artery, and the popl iteal artery were stiff and the lumens were filled with atheromatous plaque. The sural arteries opening to the bole artery was frequent. The collateral circulation at the knee perimeter was raritas rather affluent at the muscle group. All of the operations were successful, the skin temperature increased gradually after operation, and the degrees of blood oxygen saturation increased to 90%-100% at 6 hours from 0 before operation . After a follow-up of 3 to 12 months, the symptom improved obviously, rest pain disappeared, lower l imb ulcer healed. The Color Doppler ultrasound showed that most of the blood flow at the anastomotic stoma ejected into bypass circuit, and the blood flow at the distally posterior tibial artery and anterior tibial artery was l ittle. Conclusion The collateral outflow tract construction is feasible, it is an effective path after cl inical verification to solve the advanced stage ASO
ObjectiveTo explore the composition of intestinal microbiota between patients with fixed airflow obstruction asthma, reversible airflow obstruction asthma, and healthy control, and analyze the correlation between key differential bacterial distribution and clinical characteristics. MethodsFifteen patients with fixed airflow obstruction asthma (FAO) and 13 patients with reversible airflow obstruction asthma (RAO) were included, along with 11 matched healthy control subjects. Clinical data were collected, and lung function tests and induced sputum examination were performed. Blood and stool samples were tested to compare the gut microbiota status among the groups, and analyze the relationship between gut microbiota abundance and patients' blood routine, IgE levels, lung function, and induced sputum. Results The dominant bacterial compositions were similar in the three groups, but there were differences in the abundance of some species. Compared to the RAO group, the FAO group showed a significant increase in the genera of Bacteroides and Escherichia coli, while Pseudomonas was significantly decreased. The phylum Firmicutes was negatively correlated with the course of asthma, while the phylum Bacteroidetes and genus Bacteroides were positively correlated with the asthma course. Bacteroidetes was negatively correlated with Pre-BD FEV1/FVC, Pseudomonas was positively correlated with Pre-BD FEV1, Escherichia coli was negatively correlated with Post-BD FEV1/FVC, and Bacteroides was negatively correlated with Post-BD MMEF. The class Actinobacteria and the order Actinomycetales were negatively correlated with peripheral blood EOS%, while the order Enterobacteriales and the family Enterobacteriaceae were positively correlated with peripheral blood IgE levels. Furthermore, Actinobacteria and Actinomycetales were negatively correlated with induced sputum EOS%. Conclusions There are differences in the gut microbiota among patients with fixed airflow obstruction asthma, reversible airflow obstruction asthma, and healthy individuals. Bacteroides and Escherichia coli are enriched in the fixed airflow obstruction asthma group, while the Firmicutes are increased in the reversible airflow obstruction asthma group. These three microbiota may act together on Th2 cell-mediated inflammatory responses, influencing the process of airway remodeling, and thereby interfering with the occurrence of fixed airflow obstruction in asthma.
To evaluate the biological tolerance of the human liver to prolonged warm ischemia, 20 patients who underwent liver resections with hepatic inflow occlusion are reported. Biopsy of liver were performed during and after consecutive periods of hepatic ischemia, and speciments were observed under light and electron microscope. The results showed that hepatic vascular occlusion for ＜30 min, resulted in atotissular temporary but reversible pathologic and ultrastructural changes in liver, even patients with liver cirrhosis had better recovery from the operation when the hepatic ischemia was lengthen up to 40 min.
Objective To systematically evaluate the clinical effectiveness of right ventricular outflow tract (RVOT) pacing for heart disease. Methods We searched the electronic bibliographic databases, including The Cochrane Library, PubMed, EMbase, CBM, VIP, CNKI, and WANFANG database to assemble the randomized controlled trials (RCTs) of RVS Pacing compared with right ventricular apical (RVA) pacing for heart disease. The deadline of the retrieval time was January 2010. Data were extracted and evaluated by two reviewers independently with a designed extraction form. The RevMan 5.0 software was used for meta-analysis. Results A total of 16 RCTs involving 926 patients were included. The results of meta-analyses showed that right ventricular outflow tract (RVOT) pacing significantly increased the left ventricular ejection fraction of 3 months and 18 months (WMD= 3.53, 95%CI 1.02 to 6.04; WMD= 8.94, 95%CI 7.35 to 10.52).Compared with RVA pacing, RVOT pacing could significantly reduce the QRS wave duration (WMD= –22.42, 95%CI –31.05 to – 13.80) immediately after the operation. Conclusion RVOT pacing can give patients a good physiological state which is more consistent with biventricular electric conduction and lead to the hemodynamic improvement in the short term, but the long-term result is not confident.
OBJECTIVE: To study the effect of color doppler flow imaging(CDFI) technique in the design of axial pattern flap. METHODS: From April 1996 to June 1999, 10 patients with residual wound were adopted in this study. Among them, there were seven males and three females, the area of wounds ranged from 6 cm x 8 cm to 15 cm x 20 cm. Before operation, the axial pattern flaps were designed by traditional method, then CDFI technique with high frequency(5.0-7.5 MHz) was used for examining the major supply artery of the flap. At last, the modified flaps were transferred to cover the wounds. RESULTS: All the patients except one case completed the operation successfully. The cosmetic and function of the flaps were excellent. CONCLUSION: CDFI is a simple, direct and accurate method for detecting the supply artery of axial pattern flap. This technique should be popularized to avoid the blindness of flap design.
The development and progression of atherosclerosis and thrombosis are closely related to changes of hemodynamics parameters. Ultrasonic pulse wave Doppler technique is normally used for noninvasively blood flow imaging. However, this technique only provides one-dimensional velocity and depends on the angle between the ultrasound beam and the local velocity vector. In this study, ultrasonic particle image velocimetry method was used to assess whole field hemodynamic changes in normal blood vessels. By using the polynomial fitting method, we investigated the velocity gradient and assessed the shear in different blood flow velocity of 10 healthy rats. It was found that using four polynomial fitting could result in optimal measurement results. The results obtained by ultrasonic particle image velocimetry accorded with the results obtained using Doppler technique. The statistical average of cyclical vessel wall shear stress was positively related to the locational mean velocity. It is proven that ultrasonic particle image velocimetry method could be used to assess directly the real-time whole field hemodynamic changes in blood vessels and was non-invasively, and should be a good prosperous technique for monitoring complex blood flow in stenotic arteries.