fter fracture of femoral neck , the head is often encountered ayascular necrosis. It was not clearwhether the causes of the necrosis was due to injury of the artery or stagnation of venous return orboth. We had observed the hmeodynamics of the blood circulation of both fermoral head of both sides in 27 cases of subcapital fracture by E. C. T. (Emission Computerized Tomography). The resultsshowed that either old, fresh, or heal fractures showed stagnation of venous return. There wasoblite...
【Abstract】ObjectiveTo compare the hemodynamic changes during operation of portal venous intubation or splenic venous intubation in extracorporeal venous bypass of swine orthotopic liver transplantation.MethodsThirty couples of healthy Duloke pigs were selected to perform orthotopic liver transplantation. According to the difference of cannula vessel of portal venous system during extracorporeal venous bypass, these pigs were divided into two groups: portal venous intubation group (n=15) and splenic venous intubation group (n=15). Hemodynamic changes were monitored continuously.ResultsTwo recipients died in portal venous intubation group, one died of unsmooth bypass in the operation, the other died of DIC. In splenic venous intubation group there was only one recipient death, who died of hemorrhagic shock. The time of anhepatic phase of splenic venous intubation group was (44.5±7.6) min, it was significantly shorter than portal venous intubation group(51.5±8.7) min(P＜0.05). Hemodynamic changes in phase Ⅲ and phase Ⅳ of portal venous intubation group were significantly different with that of splenic venous intubation group(P＜0.05). ConclusionApplication of bypass through splenic venous intubation during extracorporeal venous bypass of swine orthotopic liver transplantation can shorten the time of anhepatic phase, keep the hemodymamics relative stable in operation, and reduce the occurrence of postoperative correlative complication. It is an effective venovenous bypass pathway.
Objective To investigate the feasibility of a long-term left ventricular assist device placed in the aortic valve annulus for terminal cardiopathy. Methods An implantable aortic valve pump （23ram outer diameter, weighing 31g） was developed. There were a central rotor and a stator in the device. The rotor was consisted of driven magnets and an impeller, the stator was consisted of a motor coil with an iron core and outflow guide vanes. The device was implanted identical to an aortic valve replacement, occupying no additional anatomic space. The blood was delivered directly from left ventricle to the aortic root by aortic valve pump like natural ventricle, neither connecting conduits nor ＂bypass＂ circuits were necessary, therefore physiologic disturbances of natural circulation was less. Results Aortic valve pump was designed to cycle between a peak flow and zero net flow to approximate systole and diastole. Bench testing indicated that a blood flow of 7L/min with 50 mmHg（1kPa = 7.5mmHg） pressure could be produced by aortic valve pump at 15 000r/min. A diastole aortic pressure of 80mmHg could be maintained by aortic valve pump at 0L/min and the same rotating speed. Conclusions This paper exhibits the possibility that an aortic valve pump with sufficient hemodynamic capacity could be made in 23mm outer diameter, 31g and it could be implantable. This achievement is a great progress to extend the applications of aortic valve pump in clinic and finally in replacing the natural donor heart for heart transplantation. Meanwhile, this is only a little step, because many important problems, such as blood compatibility and durability, require further investigation.
ObjectiveTo investigate impact of splenectomy plus pericardial devascularization on liver hemodynamics and liver function for liver cirrhosis patients with portal hypertension. MethodsThe internal diameter, maximum velocity, minimum velocity, mean velocity, and flow volume of portal vein and hepatic artery of 42 cases of liver cirrhosis with portal hypertension were measured by Doppler ultrasonic instrument on day 1 before operation and on day 7 after operation. The free portal pressures at different phases (after open abdomen, after splenic artery ligation, after splenectomy, and after devasculanrization) were read from the disposable pressure sensor. Twenty-four healthy people through physical examination were selected as control. Results① The free portal pressure of liver cirrhosis patients with portal hypertension was decreased from (29.12±1.40) mm Hg after open abdomen to (22.71±1.21) mm Hg after splenic artery ligation, and further decreased to (21.32±1.12) mm Hg after splenectomy, but increased to (22.42±1.15) mm Hg after devasculanrization, the difference was statisticly different (all P < 0.01). ② Compared with the healthy people, for the liver cirrhosis patients with portal hypertension, the internal diameter, maximum velocity, minimum velocity, and flow volume of portal vein were significantly enlarged (all P < 0.01), which of hepatic artery were significantly reduced (all P < 0.01) on day 1 before operation; On day 7 after operation, the internal diameter of portal vein was significantly reduced (P < 0.01), the maximum velocity, minimum velocity, and mean velocity of portal vein were significantly enlarged (all P < 0.01), but the internal diameter of hepatic artery was significantly reduced (P < 0.01), the maximum velocity, minimum velocity, mean velocity, and flow volume of hepatic artery were significantly enlarged (all P < 0.01). For the liver cirrhosis patients with portal hypertension, compared with the values on day 1 before operation, the internal diameter and the flow volume of portal vein were significantly reduced (all P < 0.01) on day 7 after operation; the internal diameter, maximum velocity, minimum velocity, mean velocity, and flow volume of hepatic artery were significantly enlarged (all P < 0.01) on day 7 after operation. ③ The Child-Pugh classification of liver function between before and after surgery had no significant difference (χ2=1.050, P > 0.05). ④ No death and no hepatic encephalopathy occurred, no thrombosis of splenic vein or portal vein was observed on day 7 after surgery. Conclusionsplenectomy plus pericardial devascularization could decrease portal vein pressure and reduce blood flow of portal vein, while increase blood flow of hepatic artery, it doesn't affect liver function.
ObjectiveTo observe the hemodynamic parameters of retrobulbar vessels of eyes with primary open-angle glaucoma (POAG) by using color Doppler imaging (CDI) technique. Methods Pertinent publications were retrieved from the PubMed of The National Library of Medicine, the ISI Web of Knowledge of The Institute for Scientific Information, and Cochrane Central Register of Controlled Trials. Case control studies involved POAG patients were included. Changes in retrobulbar blood flow parameters including peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI) of the ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary artery (SPCA) were evaluated by CDI. The searching time was from the data base established up to April, 2014. Meta analysis was used on the included articles, the mean difference (MD) along with 95% confidence interval (95% CI) of the blood flow parameters were calculated. ResultsTwenty-four articles were retrieved, including 1336 eyes as cases, 1102 eyes as controls. PSV of POAG eyes was statistically signiflcantly lower than controls in the OA (MD=-3.05, 95%CI:-4.49--1.61, P < 0.001), CRA (MD=-1.66, 95%CI:-1.95--1.38, P < 0.001), SPCA (MD=-0.87, 95% CI:-1.49--0.26, P=0.005). EDV of POAG eyes was statistically significantly reduced than controls in the OA (MD=-1.78, 95%CI:-2.14--1.41, P < 0.001), CRA (MD=-0.95, 95%CI:-1.17--0.74, P < 0.001), SPCA (MD=-0.53, 95%CI:-0.71--0.36, P < 0.001). Statistically significant increases in RI of POAG eyes than controls in the OA (MD=0.04, 95%CI: 0.03-0.05, P < 0.001), CRA (MD=0.06, 95%CI: 0.05-0.07, P < 0.001), SPCA (MD=0.04, 95%CI: 0.03-0.06, P < 0.001). ConclusionThis meta-analysis suggests that significant decreased velocity and increased resistance of retrobulbar blood flow are found in POAG eyes.
Objective To observe the ocular hemodynamic changes and flow direction of ophthalmic artery of patients with severe internal carotid stenosis (ICAS) and investigate the relationship between flow direction of ophthalmic artery and degree of stenosis. Methods Forty eyes of 40 patients with unilateral highgrade ICAS (29 eyes, 72.5%) and internal carotid artery occlusion (11 eyes, 27.5%) diagnosed by color Doppler flow imaging (CDFI) were enrolled in this study. There were 14 eyes (35.0%) with obvious ocular signs of ischemia, 26 eyes (65.0%) without obvious signs of ocular ischemia. The peak systolic velocity (PSV) of central retinal artery (CRA) was measured. The flow direction of the ophthalmic artery was observed by digital subtraction angiography (DSA). The PSV of CRA in eyes with different flow directions in the ophthalmic artery was comparatively analyzed. The relationship between flow direction of the ophthalmic artery and degree of stenosis was also analyzed. Results The PSV of CRA in ICAS eyes was (6.59plusmn;1.49) cm/s, which was decreased compared to fellow eye (8.95plusmn;1.35) cm/s, the difference was statistically significant (t=-7.24,P＜0.01). The PSV of CRA in eyes with signs of obvious ocular ischemia was (5.84plusmn;1.42) cm/s, which was decreased compared to eyes without signs of obvious ocular ischemia (7.00plusmn;1.39) cm/s, the difference was statistically significant (t=-2.49,P＜0.05). There were 15 eyes (37.5%) with retrograde flow in the ophthalmic artery, 25 eyes (62.5%) with forward flow of ophthalmic artery. The PSV of CRA in eyes with retrograde flow and forward flow of ophthalmic artery were (6.96plusmn;2.09), (7.01plusmn;1.42) cm/s, the difference was not statistically significant (t=-0.09，P＞0.05). Among 15 eyes with retrograde flow of ophthalmic artery, there were five eyes (33.3%) with unilateral high-grade ICAS, 10 eyes (66.7%) with internal carotid artery occlusion. The incidence rate of retrograde flow in the ophthalmic artery in eyes with internal carotid artery occlusion was higher than that in eyes with unilateral high-grade ICAS (P＜0.01). Conclusions The PSV of CRA in eyes with severe ICAS decreased compared to fellow eyes. The PSV of CRA in eyes with signs of obvious ocular ischemia also decreased compared to eyes without obvious signs of ocular ischemia. With the increase of the degree of the internal carotid artery stenosis, the incidence of retrograde flow of ophthalmic artery increased.
Neurofeedback (NF) technology based on electroencephalogram (EEG) data or functional magnetic resonance imaging (fMRI) has been widely studied and applied. In contrast, functional near infrared spectroscopy (fNIRS) has become a new technique in NF research in recent years. fNIRS is a neuroimaging technology based on hemodynamics, which has the advantages of low cost, good portability and high spatial resolution, and is more suitable for use in natural environments. At present, there is a lack of comprehensive review on fNIRS-NF technology (fNIRS-NF) in China. In order to provide a reference for the research of fNIRS-NF technology, this paper first describes the principle, key technologies and applications of fNIRS-NF, and focuses on the application of fNIRS-NF. Finally, the future development trend of fNIRS-NF is prospected and summarized. In conclusion, this paper summarizes fNIRS-NF technology and its application, and concludes that fNIRS-NF technology has potential practicability in neurological diseases and related fields. fNIRS can be used as a good method for NF training. This paper is expected to provide reference information for the development of fNIRS-NF technology.
Objective To observe the midterm haemodynamic manifestation of the home made C-L pugestrut tilting disc mechanical valve in aortic valve replacement, and to evaluate its function. Methods Twenty patients underwent aortic valve replacement over 5 years were collected and divided into two groups, the C-L pugestrut group （n=10）：aortic valve was replaced by home-made C-L pugestrut tilting disc mechanical valve（21mm）; Medtronic-Hall group （n=10）：aortic valve was replaced by Medtronic-Hall mechanical valve （21mm）. The peak transprosthetic gradients （△P）, mean transprosthetic gradients （△Pm）and effective orifice area（EOA） at rest were compared between two groups. Results At rest, △P of the C-L pugestrut group and Medtronic-Hall group were 11.63±3.23mmHg vs. 9. 78±3. 35mmHg; △Pm of the C-L pugestrut group and Medtronic-Hall group were 6. 25±2. 32 mmHg vs. 5.85±2.32mmHg： EOA of the C-L pugestrut group and Medtronic-Hall group were 1.07±0.17 cm2 vs. 1.25±0.27 cm2. There was no statistically significance in △P, △Pm and EOA between two groups（P〉0.05）. Conclusions The midterm haemodynamic results of the home-made C-L pugestrut tilting disc mechanical valve show that it has comparable haemodynamic results to those of Medtronic-Hall mechanical valve ,and it has well-done function. The home-made C-L pugestrut valve is one of the reliable mechanical heart valves.
To investigate the biomechanical effects of direct ventricular assistance and explore the optimal loading mode, this study established a left ventricular model of heart failure patients based on the finite element method. It proposed a loading mode that maintains peak pressure compression, and compared it with the traditional sinusoidal loading mode from both hemodynamic and biomechanical perspectives. The results showed that both modes significantly improved hemodynamic parameters, with ejection fraction increased from a baseline of 29.33% to 37.32% and 37.77%, respectively, while peak pressure, stroke volume, and stroke work parameters also increased. Additionally, both modes showed improvements in stress concentration and excessive fiber strain. Moreover, considering the phase error of the assist device's working cycle, the proposed assist mode in this study was less affected. Therefore, this research may provide theoretical support for the design and optimization of direct ventricular assist devices.
Objective To explore the hemodynamic monitoring value of pulse-indicated continuous cardiac output( PiCCO) during lung transplantation. Methods Twenty patients with end-stage lung disease undergone lung transplantation were enrolled. Hemodynamic states were monitored by PiCCO and Swan-Ganz standard thermodilution pulmonary artery catheter( PAC) simultaneously at six stages throughout the study. Changes in the variables were calculated by subtracting the first fromthe second measurement( Δ1 ) and so on ( Δ1 to Δ5 ) . Results The linear correlation between intra-thoracic blood volume index( ITBVI) and stroke volume index( SVIpa) was significant ( r = 0. 654, P lt; 0. 05) , whereas pulmonary artery wedge pressure ( PAWP) poorly correlated with SVIpa( P gt; 0. 05) . Changes in ITBVI correlated with changes in SVIpa ( Δ1 , r =0. 621; Δ2 , r = 0. 784; Δ3 , r = 0. 713; Δ4 , r = 0. 740; Δ5 , r = 0. 747; all P lt; 0. 05) , whereas PAWP failed. The mean bias between CIart and CIpa was ( 0. 09 ±0. 5) L·min-1 ·m-2 ; the limit of agreement was ( - 0. 89 ～1. 07) L·min-1 ·m-2 . Conclusions There is good correlation between the two methods of PiCCO and PAC for reflecting the change of heart preload. PiCCO is reliable in hemodynamic monitoring in patients undergone lung transplantation.