【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.
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...
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.
The hemodynamics changes of the common carotid arteries in 10 SD rats were measured with a color doppler flowmetry in an attempt to define the changes resulting from end-to-end anastomosis. The left common carotid arteries were divided and followed by end-to-end anastomosis. The systolic mean peak velocities in the left arteries were measured at the proximal, distal and anastomotic sites and in the right intact arteries as well at 6, 12, 24, 48, 72 and 120 hours after repair. The percentage of area reduction at anastomosis was calculated from these data. The results indicated that the systolic mean peak velocity at the anastomotic sites was significantly increased as compared to the velocity at the proximal, distal and contralateral sites (P lt; 0.05). The velocity at the distal sites was significantly lower than that from the proximal and contralateral sites (P lt; 0.05), the mean percentage of the reduction was 33.18% and 33.33%, respectively. From 6 hours to 120 hours after anastomosis of arteries there was various degree of narrowing at the site of anastomosis. The mean per cent of stenosis was 42.48%. It was concluded that from 6 to 120 hours after end-to-end anastomosis of the small arteries, the velocity at the anastomotic site was increased as compared to the velocities at pre- and post-anastomotic sites. The increase of velocity at the site of anatomosis was caused by stenosis at the anastomosis.
It has been found that the incidence of cardiovascular disease in patients with lower limb amputation is significantly higher than that in normal people, and the risk of developing coronary atherosclerosis is much higher than that in other high-risk groups. Numerous studies have confirmed that high systolic and diastolic blood pressures are potential risk factors for coronary artery disease, and it has been demonstrated that the ascending aortic pressure during diastole increases after amputation. However, the relationship between lower limb amputation and coronary atherosclerosis has not been fully explained from the perspective of hemodynamic environment. Therefore, in this study, a centralized parameter model of the human cardiovascular system and a three-dimensional model of the left coronary artery were established to investigate the effect of amputation on the hemodynamic environment of the coronary artery. The results showed that the abnormal hemodynamic environment induced by amputation, characterized by factors such as increased diastolic pressure in the ascending aorta, led to a significant expansion of the low wall shear stress (WSS) region on the outer lateral aspect of the left coronary artery bifurcation during diastole. The maximum observed increase in the area of low WSS reached up to 50.5%. This abnormal hemodynamic environment elevates the risk of plaque formation in the left coronary artery. Moreover, the more severe the lower limb atrophy, the greater the risk of coronary atherosclerosis in amputees. This study preliminarily reveals the effect of lower limb amputation on the hemodynamic environment of the left coronary artery.
ObjectiveTo observe the effects of carotid artery stenting (CAS) on ophthalmic artery blood flow in patients with ischemic ophthalmopathy (IOP).MethodsA prospective case-control study. Sixty IOP patients (60 eyes) who met inclusive criteria for CAS were enrolled in this study. There was 50% stenosis of internal carotid artery on one side at least confirmed by color doppler flow imaging (CDFI). Among 60 eyes, there were 3 eyes with central retinal artery occlusion, 15 eyes with retinal vein occlusion, 37 eyes with ischemic optic neuropathy, 5 eyes with ocular ischemia syndrome. The patients were randomly divided into CAS group (32 eyes of 32 patients) and medicine therapy group (28 eyes of 28 patients). The difference of age (t=1.804) and sex (χ2=1.975) between two groups was not significant (P＞0.05). The examinations of fundus fluorescein angiography (FFA), CDFI and digital substraction angiography (DSA) were performed before, 1 week and 6 months after treatment. The following parameters were recorded: arm-retinal circulation time (A-Rct), peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistance index (RI) in the ophthalmic artery (OA) and central retinal artery (CRA), and the best corrected visual acuity (BCVA).ResultsThere was no significant differences in A-Rct (t=1.354) and BCVA (t=0.376) between the two groups before treatment (P＞0.05). Also, there was no significant differences in PSV (t=?0.294, ?2.446), EDV (t=0.141, ?0.305), and RI (t=?0.222, ?0.694) of OA and CRA between the two groups before treatment before treatment (P＞0.05). Compared with the medicine therapy group, the lower A-Rct was found in the CAS group at different time points after the treatment. The difference was significant on 1 week after treatment (t=?3.205, P＜0.05), but not on 6 months after treatment (t=1.345, P＞0.05). The BCVA of eyes in the two groups were increasing with the extending of time of therapy. Compared with the medicine therapy group, the better BCVA was found in the CAS group at different time points after the treatment (t=0.800, 1.527; P＜0.05). Compared with the medicine therapy group, the higher PSV, EDV and lower RI of OA and CRA were found in the CAS group at different time points after the treatment. (P＜0.05).ConclusionCompared with conventional medicine therapy, CAS shows earlier effects in improving ocular hemodynamics for IOP patients with carotid artery stenosis, which benefits visual function improvement of the patients.
Objective To investigate the hemodynamic performance of valved bovine jugular vein conduits (BJVC) for right ventricular outflow tract reconstruction in canine model. Methods The BJVC that were treated with the glutaraldehyde were implanted between the pulmonary artery and right ventricle in seven young canines. Right ventricular and pulmonary artery pressures were measured directly before and after the implantation. Hemodynamic evaluations were carried out by echocardiography and cardiac catheterization after the implantation. Results Seven canines were survival one year after the implantation. The pulmonary artery pressures (including systolic pressure, diastolic pressure and mean pressure) had not significantly changed after reconstruction with the conduits. The right ventricular diastolic pressures had not increased after the reconstruction, but the right ventricular systolic pressure and mean pressure had increased. One year later, the echocardiography showed valve motion with no obvious thickening of the leaflets. No graft kinking or obvious regurgitation of the valve was observed. Cardiac catheterization and angiography showed that the pressure gradients between the right ventricle and the conduits varied from 3 to 19mmHg, the diastolic pressures in the conduits were higher than that of right ventricle((Plt;)0.01), and the conduits and pulmonary arteries had no obvious obstruction. Conclusion The glutaraldehyde-fixed bovine jugular vein conduit has good hemodynamic performance in the pulmonary circulation.
Objective To approach the effect of neck hyperextension position on hemodynamics of vertebral artery following thyroidectomy， and analyze the correlation between the change of hemodynamics and nausea and vomiting. Methods One hundred and fifty-eight patients with preparing for thyroidectomy （thyroidectomy group） and 89 patients with laparoscopic cholecystectomy （LC， LC group） were selected. The anesthesia method and the anesthesia drugs were the same in two groups. The indexes of hemodynamics of the bilateral vertebral artery at 6 h before and after thyroidectomy were measured. The difference of nausea and vomiting was observed and compared in two groups. Results The average blood flow velocity of the bilateral vertebral artery reduced and the blood flow decreased at 6 h after thyroidectomy as compared with at 6 h before thyroidectomy （P＜0.05）. The rates of nausea and vomiting of 0，2， 3， 4 times in the thyroidectomy group were significantly higher than those in the LC group （P＜0.05， P＜0.01）. The durations of nausea and vomiting of 1， 2， 3， 4 times in the thyroidectomy group were also significantly longer than those in the LC group （P＜0.01）. There was a positive correlation between the nausea and vomiting and the changes of blood flow velocity or blood flow （change of blood flow velocity：rs=0.697， P=0.03；change of blood flow：rs=0.897， P=0.01）. Conclusions There is a certain effect of the neck hyperextension position on hemodynamics of the bilatreal vertebral artery， and which might affect the nausea and vomiting following thyroidectomy.
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.
ObjectiveTo investigate the expression of tumor necrosis factor α(TNF-α ) in isolated rat heart at different time points after myocardial hypoxia/reoxygenation. MethodsThe isolated langendorff perfused rat heart model was established. Forty-eight SD rats were randomly divided into four groups: a sham group, hypoxia/reoxygenation groups including a H/R 0.5 h group, a 1 h group and a 2 h group. The heart rate(HR), the 1eft ventricular development pressure(LVDP), maximal rates of increase/decrease of the left ventricular pressure(±dp/dtmax) were continuously recorded. The concentrations of TNF-α and creatine kinase-MB(CK-MB) in myocardium, mRNA expression of TNF-α in myocardium were tested. Ultra structure of myocardium was observed under electron microscope. ResultsThe levels of LVDP, ±dp/dtmax, and HR of hypoxia/reoxygenation group were significantly lower than those in the sham group(P<0.05).The levels of TNF-α and CK-MB and the expressions of TNF-α at mRNA level in the hypoxia/reoxygenation group were higher than those in the sham group(P<0.05).There were significant differences in the above parameters among the H/R 0.5 h group, the 1 h group, the 2 h group(P<0.05).The concentrations of TNF-α and CK-MB, the mRNA expression of TNF-α were higher in the I/R 2 h group than those in the other two groups. ConclusionThe high expression of TNF-α in myocardium after myocardial hypoxia/reoxygenation in rats is related to the degree of myocardium damage and may lead to myocardial injury.