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 analyze the effect of monitoring and modulating the portal vein pressure and blood flow during living donor liver transplantation （LDLT） on preventing small-for-size-syndrome (SFSS). Methods Data of forty-four LDLT recipients between Oct.2007 and Oct.2008 were reviewed. Actual graft-to-recipient weight ratio（GRWR）, portal vein flow and pressure during operation and syndrome of SFSS after operation were recorded. The patients received splenectomy or splenic artery ligation according to actual GRWR, portal vein flow and pressure and WBC. Relationships between patients’ GRWR, portal vein flow, portal vein pressure and occurrence of SFSS were analyzed. Results Six patients received splenectomy and 7 patients received splenic artery ligation to decrease the portal vein flow and pressure during the operation. The portal vein flow and pressure decreased after splenectomy （Plt;0.05）. The portal vein pressure decreased （Plt;0.05） and the portal vein flow had no significant change after splenic artery ligation （P＞0.05）. No SFSS occurred after operation. Conclusion Modulation of portal vein flow and pressure by splenectomy or splenic artery ligation during LDLT operation can decrease the portal vein flow and pressure, and which can prevent the incidence of SFSS.
This study was performed on canine femoral veins which were interpositionally implanted into the femoral arteries and the investigation was in terms of zero-stress state, compliance and hemodynamic assessment. The results revealed that the vein grafts had the similar characteristics of compliance with the normal veins. Using Doppler ultrasonography to monitor the blood flow velocity through the vein grafts, the hemodynamic parameters such as pulsatility index (PI) and blood flow volume were evaluated consecutively within one month after the operations .No significant differences were found between these parameters at different time points. It was suggested that autogenous vein graft had an adaptive course when operating in an arterial hemodynamic circumstances and It’s mechanical changes did not bear upon the hemodynamics through the vein graft.
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.
Abstract: Objective To examine the cell viability and hemodynamic functions of the stented homograft valves preserved in liquid nitrogen. Methods Cell viability of the stented homograft valve preserved in liquid nitrogen after 3 months of preservation (experimental group，n=6) was examined using flow cytometer. Fresh homografts served as control group (n=6). We prepared three sorts of stented homograft valve(21#, 23#, 25#) preserved by liquid nitrogen. In vitro pulsatile flow tests were performed on valves of two groups. Effective opening area EOA),transvalve pressure gradient and regurgitation ratio were recorded at various flow volume, and compare with Perfect bioprosthetic valve. Results The results revealed that the death ratio of endothelial cell was 10.24%±1.71% in the experimental group, and 9.09%±2.72% in the control group (P=0.441). The death ratio of smooth muscle cell was 8.76%±1.82% in the experimental group, and 7.84%±0.59% (P=0.178) in the control group. The death ratio of total cell was 8.79%±1.44% in the experimental group, and 7.40%±0.49% in the control group (P=0.072). There were no significantly differences between two groups. The transvalve pressure gradient of two groups of valve depended on the flow volume, and increased with the flow volume increasing. The transvalve pressure gradient of the stented homograft valve was higher than that of Perfect valve. Regurgitation ratio of the stented homograft valve was bigger than Perfect valve’s. EOA had an increasing character when flow volume increased. EOA of the stented homograft valve was smaller than that of Perfect valve’s. Conclusion Liquid nitrogen can offer the benefit of cell viability of the stented homograft bioprosthetic valves. The stented homograft valve has salisfactory hemodynamic functions.
Objective To analyse the characteristic of hemodynamic changes during off-pump coronary artery bypass grafting （OPCAB）. Methods One hundred consecutive patients received OPCAB and the hemodynamic changes were monitored during the grafts was anastomosed. They were anastomosis of the left internal mammary artery （LIMA） to left anterior descending （LAD） in 97 patients, the anastomosis of saphenous vein （SV） or radial artery（RA） to right coronary artery （RCA） including posterior descending artery （PDA） and posterior left branch （PLB） in 84 patients, to left circumflex coronary artery （LCX） in 50 patients, to optuse marginal artery（OM） in 27 patients, to diagonal artery （DG） in 25 patients. The grafts number in each patient was 3. 1±0. 7. Results Hemodynamics changed when LAD and DG were anastomosed with significantly increase of heart rate （HR）, significantly decrease of mean arterial pressure （MAP） and left ventricular stroke work index （LVSWI, P〈0.05）. Hemodynamics changed when LCX,PDA,PLB,OM were anastomosed with significantly increase of HR and center veinous pressure （CVP, P 〈 0. 05）, significantly decrease of MAP, cardiac index （CI）, stroke index （SI）, right ventricular ejection fraction （RVEF）, right ventricular end-diastolic volume （RVEDV）, LVSWI and right ventricular stroke work index （RVSWI,P〈0.05）. Hemodynamics tended to be stable and CI improved at the end of operation. Conclusion There are no or little hemodynamic changes during the LAD and DG were anastomosed in OPCAB, while hemodynamics changed significantly during LCX, PDA, PLB and OM were anastomosed. Hemodynamics become stable and CI improves after operation.
ObjectiveTo investigate the effects of prone position ventilation on oxygenation,hemodynamics and airway drainage in patients with severe aspiration pneumonia with acute respiratory distress syndrome (ARDS). Methods28 patients with severe aspiration pneumonia with ARDS admitted between January 2010 and June 2012 were recruited in the study. They were ventilated in prone position with sedation and paralysis. Mean blood pressure (MAP),heart rate (HR),central venous pressure (CVP),pulse oxygen saturation (SpO2),arterial oxygen tension (PaO2),carbon dioxide partial pressure (PaCO2),oxygenation index (PaO2/FiO2) and sputum drainage were recorded in the time points of initial supine position,prone position 1h,prone position 2h,and return to supine position 2h. ResultsCompared with the time point of initial supine position,PaO2 and PaO2/FiO2 increased significantly after 1 and 2 hours in prone position [PaO2:(85±12)mm Hg and (97±10)mm Hg vs. (65±11)mm Hg;PaO2/FiO2:(150±37)mm Hg and (158±50)mm Hg vs. (130±28)mm Hg;all P<0.05]. The effects of oxygenation improving were persistent 2h after return to supine position [PaO2:(87±11)mm Hg;PaO2/FiO2:(150±52)mm Hg,P<0.05]. There was no significant difference in MAP,HR,CVP,or SpO2 during the study. Airway sputum drainage was significantly increased 2h after in prone position compared with that in initial supine position [(15.3±2.0)mL vs. (8.1±1.1)mL,P<0.05]. Airway sputum drainage had no significant difference among 1h afer prone position,2h after return to supine position and the initial supine position [(9.1±1.0)mL and (8.3±1.2) mL vs. (8.1±1.1)mL,P>0.05]. ConclusionProne position ventilation can improve the oxygenation in patients with severe aspiration pneumonia with ARDS,and the effects of oxygenation improvement can be persistent till 2h after return to supine position. Prone position ventilation can improve sputum drainage without significant influence on hemodynamics,thus can be used as an adjuvant treatment for severe aspiration pneumonia with ARDS. The duration of prone position ventilation needs to be prolonged for patients with much airway secretion.
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.
Objective To observe the effect of ophthalmotonus intervention on ocular hemodynamics in patients with ischemic ophthalmopathy (IOP). Methods 106 IOP patients (106 eyes) were enrolled in this study, including 74 eyes with nonarteritic anterior ischemic optic neuropathy (NAION), 20 eyes with retinal artery occlusion (RAO) and 12 eyes with ocular ischemia syndrome (IOS). The patients were randomly divided into ophthalmotonus intervention group and control group. There were 37 NAION eyes, 10 RAO eyes and six IOS eyes in each group. The patients of ophthalmotonus intervention group received lowering intraocular pressure treatment in addition to the basic therapy to reduce the intraocular pressure to le;12 mm Hg (1 mm Hg=0.133 kPa) or decreased by 7-8 mm Hg, or in a 20%-30% reduction. The patients of control group avoided lowering intraocular pressure treatment. The arm-retinal circulation time (A-RCT) and the peak systolic velocity (PSV), end diastolic velocity (EDV) and resistance index (RI) of ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (PCA) before and one week after treatment were comparatively analyzed by fluorescence fundus angiography (FFA) and color Doppler flow imaging. Results The differences of A-RCT before treatment in ophthalmotonus intervention group and control group in NAION, RAO and IOS patients were not statistically significant (t=0.869, 0.119, 0.000; P＞0.05). The differences of PSV (OA:t=0.586, 0.040, 0.067; CRA:t=0.285, 0.057, 0.775; PCA:t=0.658, 0.653, 1.253), EDV (OA:t=0.274, 0.080, 0.093; CRA:t=0.781, 0.077, 0.277; PCA:t=0.200, 0.209, 0.299) and RI (OA:t=0.121, 0.153, 0.138; CRA:t=0.172, 0.242, 0.642; PCA:t=1.053, 1.066, 0.266) of OA, CRA and PCA before treatment in ophthalmotonus intervention group and control group were not statistically significant (P＞0.05). Compared with control group, A-RCT shortened obviously (t=2.573, 2.236, 2.607; P＜0.05) in ophthalmotonus intervention group one week after treatment. Compared with control group, PSV (OA:t=2.367, 2.368, 2.267; CRA:t=0.775, 1.927, 2.775; PCA:t=2.253, 2.353, 2.353) and EDV (OA:t=2.303, 2.236, 2.503; CRA: t=2.277, 2.377, 2.577; PCA:t=2.299, 2.399, 2.299) of OA, CRA and PCA increased obviously (P＜0.05), RI of OA, CRA and PCA decreased obviously (OA:t=2.238, 2.387, 2.228; CRA:t=2.342, 2.442, 2.542; PCA:t=2.266, 2.366, 2.266; P＜0.05) one week after treatment in treatment group. Conclusion Ophthalmotonus intervention can improve the ocular hemodynamics in IOP patients.
It has been found that the incidence of cardiovascular disease in patients with lower limb amputation is significantly higher than that in normal individuals, but the relationship between lower limb amputation and the episodes of cardiovascular disease has not been studied from the perspective of hemodynamics. In this paper, numerical simulation was used to study the effects of amputation on aortic hemodynamics by changing peripheral impedance and capacitance. The final results showed that after amputation, the aortic blood pressure increased, the time averaged wall shear stress of the infrarenal abdominal aorta decreased and the oscillatory shear index of the left and right sides was asymmetrically distributed, while the time averaged wall shear stress of the iliac artery decreased and the oscillatory shear index increased. The changes above were more significant with the increase of amputation level, which will result in a higher incidence of atherosclerosis and abdominal aortic aneurysm. These findings preliminarily revealed the influence of lower limb amputation on the occurrence of cardiovascular diseases, and provided theoretical guidance for the design of rehabilitation training and the optimization of cardiovascular diseases treatment.