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.
Early enteral nutrition after cardiopulmonary bypass (CPB) has been shown to have beneficial effects on intestinal integrity, lower mortality and also on the patient’s immunocompetence. Even in critical patients after CPB, enteral nutrition should be reasonable to start early and also be supplemented by parenteral nutrition in order to meet energy requirement. We conclude that enteral nutrition is preferable in the majority of patients with severe hemodynamic failure, but gastrointestinal complication and hypocaloric feeding should be simultaneously noticed. This paper comprehensively described enteral nutrition’s protective mechanism and effects on digestive system, enteral nutrition’s implementing methods after CPB, and problems or prospects needing attention in execution.
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.
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.
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.
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.
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.
Objective Comparing postoperative change of blood gas and hemodynamic status in patients underwent a right ventricletopulmonary artery (RVPA) conduit or a modified BlalockTaussig (mBT) shunt for pulmonary atresia with ventricular septal defect and without major arterial pulmonary collaterals (MAPCAs), to affirm the effect on oxygen supply /demand with different procedure. Methods From July 2006 to October 2007, 38 patients with pulmonary atresia and ventricular septal defect without MAPCAs were divided into two groups according to different procedures: RVPA group (n=25) and mBT group (n=13).Perioperative mortality, blood gas and hemodynamic data during postoperative 48 hours, including heart rate, blood pressure, systemic oxygen saturation, mixed venous oxygen saturation, oxygen excess factor, inotropic score were compared in both groups. Results The difference in the mortality between RVPA group (4.0％，1/25) and mBT group （7.7％，1/13) showed no statistical significance（Pgt;0.05）. The total of 33 patients were followed up, the followup time was from 6 to 18 months.11 patients (4 patients in mBT group, 7 patients in RVPA group) underwent corrected procedures during 9 to 18 months after palliative procedures, one case died of elevated pulmonary vascular resistance and right ventricle failure. The mixed venous oxygen saturation at 24h and 48h after surgery were higher than that at 6h after surgery (Plt;0.01) both in RVPA group and mBT group. The systolic blood pressures at 6h, 24h, 48h after surgery in RVPA group were lower than those in mBT group (P=0.048，0.043， 0.045)，the mean systemic blood pressures in RVPA group were higher than those in mBT group (P=0.048, 0.046, 0.049),the diastolic blood pressures in RVPA group were higher than those in mBT group (P=0.038, 0.034, 0.040)， the inotropic scores in RVPA group were lower than those in mBT group (P=0.035， 0.032，0.047). Conclusion The blood pressures and inotropic scores are found significantly different in RVPA conduit and mBT procedures, while postoperative systemic oxygen delivery areequivalent. Both RVPA and mBT patients decline to nadir in hemodynamic status at 6 h after surgery.
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.