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find Keyword "Hemodynamics" 39 results
  • Effect of lowering intraocular pressure treatment on ocular hemodynamics in patients with nonarteritic anterior ischemic optic neuropathy

    Objective To observe the effect of lowering intraocular pressure(IOP) treatment on ocular hemodynamics in patients with nonarteritic anterior ischemic optic neuropathy (NAION). Methods A total of 68 patients with NAION (68 eyes) were enrolled in this study. The patients were randomly divided into treatment group (38 eyes of 38 patients) and control group (30 eyes of 30 patients). All the patients were received methylprednisolone pulse therapy (200 mg, three days), vasodilator therapy with intravenous infusion of Xueshuantong solution (300 mg), optic nerve nutritional therapy with mouse nerve growth factor (30 mu;g) and acupoint injection in temporal with compound anisodine (2 ml). The total course was 10 days. The patients of treatment group received IOP lowering treatment to reduce the IOP to ge;8 mm Hg (1 mm Hg=0.133 kPa) or in a 30% reduction. The patients of control group received no IOP lowering treatment. The peak systolic velocity (PSV), pulsatility index (PI) and resistance index (RI) of ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (PCA) before and after treatment were comparatively analyzed by color doppler flow imaging. Results The differences of PSV (t=1.023, 1.145, 0.569), PI (t=0.679, 0.956, 1.634) and RI (t=0.816, 1.657, 0.998) of OA, CRA and PCA before treatment in treatment group and control group were not statistically significant (P>0.05). Compared with before treatment, PSV (t=3.150, 7.650, 3.520) and PI (t=2.420, 5.430, 7.650) of OA, CRA and PCA increased obviously (P<0.05), RI of OA, CRA and PCA decreased obviously (t=5.320, 9.640, 18.360;P<0.05) after treatment in treatment group. In control group, the differences of PSV (t=2.090, -2.550, -2.100) and PI (t=-2.310, -2.230, -4.490) of OA, CRA and PCA between before and after treatment were not statistically significant (P>0.05); but the differences of RI of OA, CRA and PCA between before and after treatment was statistically significant (t=2.970, 2.160, 2.690;P<0.05). Compared with control group, PSV (t=2.632, 2.135, 5.364) and PI (t=3.251, 2.432, 4.243) of OA, CRA and PCA increased obviously (P<0.05), RI of OA, CRA and PCA decreased obviously (t=3.664, 2.938, 4.324;P<0.05) after treatment in treatment group. Conclusion Lowering intraocular pressure treatment can improve the ocular hemodynamics in NAION patients.

    Release date:2016-09-02 05:22 Export PDF Favorites Scan
  • MECHANICAL AND HEMODYNAMIC CHANGES IN AUTOGENOUS VEIN GRAFTS

    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.

    Release date:2016-09-01 11:33 Export PDF Favorites Scan
  • INFLUENCE OF PEDICLE LENGTH ON PERFORATOR FLAP IN HEMODYNAMICS

    Objective To study the influence of the pedicle length on the perforator flaps in hemodynamics. Methods Four mature swine (2 males, 2 females; weight, 23.0±2.0 kg) were applied to the experiment.Two transverse abdominal skin flaps, based on the superior epigastric pedicle orits rectus abdominal muscle perforators, were designed; each swine was used as its own control. At 2 hours and 1, 2, 3 weeks postoperatively, the skin paddle perfusion and the blood stream velocity in the superior epigastric artery were measured by the Laser Doppler Flowmeter and the Color Doppler Ultrasound, respectively. Flap survival percentages were calculated by the grid method at 1 week postoperatively. The swine were euthanatized, and they underwent angiography at 3 weeks postoperatively. Results At 2 hours and 1 week after operation, edema of the perforator flaps with the superior epigastric pedicle was more severe than that of the skin flaps with the rectus abdominal muscle perforator, and the skin perfusion had a statistical difference between the two kindsof flaps (Plt;0.05). The skin paddle viability and the skin perfusion had nostatistical difference after the first week postoperatively (Pgt;0.05). At 2hours and 1 week after operation, the blood stream velocity in the superior epigastric artery in the perforator flap with the superior abdominal artery pediclewas reduced, and there was a statistical difference between the two kinds of flaps (Plt;0.05); however, the velocity was almost the same after the first week postoperatively. Conclusion The excessively long pedicle of the perforator skin flap may have an unfavorable influence on the flap perfusion,especially during the first week after operation, because of the vascular compromise during the dissection of the long pedicle. The blood vessel anastomosis atthis level of the blood vessels may have no relationship with the perforator flap in hemodynamics. This study can also indicate that the ligation of the branches in the recipient vessels cannot make the perforator flaps overperfused.

    Release date:2016-09-01 09:22 Export PDF Favorites Scan
  • A STUDY ON HEMODYNAMIC AND MORPHOLOGIC CHANGES OF DERMAL NUTRIENT DISTURBANCE IN VENOUS DISEASE

    By using noninvasive venous plethysmography, venography and skin morphology, 44 patients (57 limbs) with chronic venous insufficiency (CVI) in lower extremity were studied , and compared with 12 normal subjects (24 limbs). The results showed that dermal nutrient disturbance caused by deep venous insufficiency accounted for 68%, and followed by perforating venous insufficiency was 44%. Furthermore compared venous refill time (VRT), segmented venous capacitancy (SVC) and maximum venous outflow (MVO) of dermal nutrient disturbance with those of exterior normal skin and normal subjects; and compared VRT, SVC, MVO of deep vein 3-4 stage reflux with those of 1-2 stage reflux and normal subjects,the differences were very significant (P<0.05). Compared the VRT of perforating incompetence with that of competence (P<0.01). Dermal pathology and ultramicrostructure showed that leucocytes trapping in capillary was a cause of microangiopathy. These results suggest that deep vein 3-4 stage reflux followed by calf perforating insufficiency was a main cause for dermal nutrient disturbance; lower extremity VRT reduced obviously and SVC increased significantly were hemodynamic character, leucocytes trapping in capillary was pathology basis of skin damage.

    Release date:2016-08-29 03:18 Export PDF Favorites Scan
  • Selection Cannula Vessel of Portal Venous System in Extracorporeal Venous Bypass of Swine Orthotopic Liver Transplantation

    【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 venovenous bypass pathway.

    Release date:2016-09-08 11:53 Export PDF Favorites Scan
  • Hemodynamic study of right ventricular outflow tract reconstruction with valved bovine jugular vein conduit in canine model

    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.

    Release date:2016-08-30 06:28 Export PDF Favorites Scan
  • Hemodynamic Monitoring by Pulse-Indicated Continuous Cardiac Output Analysis During Lung Transplantation

    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.

    Release date:2016-08-30 11:53 Export PDF Favorites Scan
  • The Effective Orifice Area and Haemodynamics of 19mm St. Jude Regent Valve——An Early in Vivo Study

    Abstract: Objective To investigate the in vivo effective orifice area (EOA) and whether prosthesispatient mismatch (PPM) is going to happen after 19mm St.Jude Regent valves replacement were performed. Methods Twentythree patients with valvular heart diseases were divided into 2 groups according to aortic annular diameter. 19mm St. Jude Regent valves were replaced in aortic valve place (Regent valve group), and 21mm other doubleleaflet mechanical valves were replaced in aortic place (other valves group). All of the operations were accomplished under cardiopulmonary bypass in West China Hospital. All of the patients were followed up in 3 to 6 months after their surgery processes. Color Doppler echocardiography was used to measure the hemodynamic parameters in their followup. Then left ventricular mass (LV mass), EOA and effective orifice area index (EOAI) etc. were calculated and compared by using SPSS 12.0. Results No cardiac episodes were detected during the perioperative period and 36 months after operation. LVmass reduced in 36 months after operation in both groups. No statistical significance of EOA, EOAI and LVmass reduction were detected between the two groups. Conclusions (1)The EOA and in vivo hemodynamic effects of 19mm Regent valve are similar to 21mm other double leaflet mechanical valve. (2)It is safe to use 19mm Regent valve in those patients whose aortic annular diameter are small and need double valve replacement. Using 19mm Regent valve will not cause short time cardiac episodes and PPM. (3)More further works should be done to make sure what is the standard of PPM in Chinese people, such as enlarging the patients number and prolonging the followup time. (4) Further clinical and followup works should be done to make St.Jude Regent valve’s feature out.

    Release date:2016-08-30 06:16 Export PDF Favorites Scan
  • Ocular ischemic appearance associated with different carotid artery stenosis degree and its effects on hemodynamics of eye and central retinal artery

    ObjectiveTo observe ocular ischemic appearance (OIA) associated with carotid artery stenosis and its effects on the hemodynamics of central retinal artery (CRA) and ophthalmic artery (OA). MethodsA total of 30 normal persons and 60 patients with carotid artery stenosis diagnosed by color Doppler flow imaging (CDFI) and digital subtraction angiography (DSA) were enrolled in this prospective study.Sixty patients were randomly divided into 2 groups:30 patients with the carotid artery stenosis degree < 60% and 30 cases with the carotid artery stenosis degree≥60%. Thirty normal persons were enrolled in the normal control group. All patients underwent a comprehensive eye examination to determine if OIA exists. The Doppler spectral patterns of CRA and OA were observed by CDFI. The peak systolic velocity (PSV), end diastolic velocity (EDV), blood vessel diameter (BVD) and resistance index (RI) of CRA and OA were measured. ResultsIn the group of the carotid artery stenosis degree≥60%, 24/30 patients (80.0%) had the ophthalmic symptoms and 9/30 patients (30.0%) had ophthalmic signs. In the group of the carotid artery stenosis degree < 60%, 9/30 patients (30.0%) had the ophthalmic symptoms and 3/30 patients (10.0%) had ophthalmic signs. For patients with≥60% stenosis, CDFI revealed a bread-like waveform of CRA, and single peak of OA instead of the typical 3-peak/2-notch waveform. For patients with < 60% stenosis, CDFI revealed a normal pattern of CRA and OA (3-peak/2-notch). The PSV(t=5.255, P=0.007) and EDV(t=4.949, P=0.005) of CRA in the stenosis≥60% group were statistically decreased compared to the normal control group, but the BVD(t=0.457, P > 0.05)and RI(t=0.213, P > 0.05)were normal. The PSV, EDV, BVD and RI of CRA in the stenosis < 60% group were normal(P > 0.05). The PSV(t=4.457, P=0.010)and EDV(t=4.588, P=0.009)of CRA in the stenosis≥60% group were statistically decreased compared to the stenosis < 60% group, but the BVD and RI were the same between these 2 groups. ConclusionPatients with carotid stenosis≥60% had a higher OIA incidence, reduced PSV, EDV of their CRA, while had no significant changes of OA hemodynamics.

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  • THE HEMODYNAMIC CHANGES AFTER END-TO-END ANASTOMOSIS OF THE SMALL ARTERIES IN RATS

    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.

    Release date:2016-09-01 11:07 Export PDF Favorites Scan
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