【Abstract】ObjectiveTo investigate the effects of CO2 pneumoperitoneum on blood flow of carotid arteries in atherosclerosis rabbits.MethodsFifty Japan white rabbits were randomly divided into control group and three atherosclerosis groups. In atherosclerosis group, the rabbits were randomly subjected to CO2 pneumoperitoneum with an intraabdominal pressure of 0 mm Hg, 10 mm Hg or 15 mm Hg for 2 hours, after the model were created by feeding the rabbits with high fatty diet. The blood flow of the common carotid arteries were measured by electromagnetic blood flowmeter. Artery blood samples were collected for blood gas analysis at 30 minute intervals. ResultsHigher insufflation pressures and longer duration of CO2 pneumoperitoneum were associated with greater increase in blood flow of common carotid arteries. Compared with those in control group and atherosclerosis group with 0 mm Hg CO2 pneumoperitoneum, there were statistically significant increases in blood flow of the common carotid arteries during CO2 pneumoperitoneum in 10 mm Hg and 15 mm Hg pneumoperitoneum group, the changes in 15 mm Hg pneumoperitoneum group were more significant than those in 10 mm Hg pneumoperitoneum group (Plt;0.05). When compared with the blood flow before insufflation, those in 10 mm Hg and 15 mm Hg pneumoperitoneum group also increased significantly during CO2 pneumoperitoneum, even at 30 minute after desufflation (Plt;0.05). However, those in control group and 0 mm Hg pneumoperitoneum group did not change significantly (Pgt;0.05). There were significant decrease in pH and significant increase in PCO2 in both 10 mm Hg and 15 mm Hg groups, when compared with presufflation values or those in control group and 0 mm Hg pneumoperitoneum group(Plt;0.05). The changes in pH and PCO2, however, were no significant at any time point in control group and 0 mm Hg pneumoperitoneum group (Pgt;0.05). HCO3- did not change significantly in either group(Pgt;0.05).ConclusionUnder atherosclerosis conditions, CO2 pneumoperitoneum has an adverse influence on the blood flow of the common carotid arteries which may be associated with increased intrabdominal pressure,absorbed CO2 gas.
Objective To study the changes of blood flow of the already-compressed cauda equina under dynamic burden, high frequency stimulation (HFS) and increased additional compression, and to clarify the mechanism of neurogenic intermittent claudication. Methods Thirty SD rats were divided into 5 groups, 6 in each. All groups were operated with laminectomy of the fifth lumbar verfebra. One hour after the measurement of blood flow,in 4experimental groups, the silicon sheets were inserted into the spinal canal of L4 and L6 to cause double level compression of cauda equina by 30%. Two hours after onset of compression, no dynamic burden was introduced to the subjects of the experimental group 1. Only HFS was introduced to the subjects of the experimental group 2 for 6 minutes. Both HFS and increased additional compression were introduced to the subjects of the experimental group 3 for 6 minutes. While only increased additional compression was introduced to the subjects of the experimental group 4 for 6 minutes. The subjects of control group only underwent laminectomy of the fifth lumbar vertebra and HFS 6 minutes. The blood flow of cauda equina was measured with laser Doppler flowmeter. Results In the first 2 hours, there was no significant change of cauda equina blood flow in the control group. During the time of HFS, the blood flow increased significantly to 186.4%±31.5% of initial value (Plt;0.05). In the experimental group 1, there was no blood flow change during the period of dynamic burden（110.4％±7.5％，Pgt;0.05）. After introduction of dynamic burden, there was no blood flow changes in the experimental group 2 (111.6％±17.6％，Pgt;0.05). The blood flow in the experimental group 3 decreased to 65.3%±10.7% of initial value (Plt;0.05); and the blood flow in the experimental group 4 decreased to 60.1%±9.2% of initial value (Plt;0.01). There was no significant difference between the experimental groups 3 and 4 (Pgt;0.05). Conclusion The results above show that during the period of increased impulse transmission, double level compression of cauda equina may limit the increase of blood flow, which maycause relative ischemia. If there is increased additional compression along with increased impulse transmission, the blood flow will decrease significantly, which will cause absolute ischemia.
Purpose To examine the change of optic disc blood flow in primary open angle glaucoma(POAG) patients after cold provocation test and nifedipine administration． Methods Using Heidelberg retinal flowmetry (HRF),the blood flow of optic disc of glaucoma patients and normal control subjects were measured under basal condition, after cold provocation test,and after nifedipine administration. Results The mean optic disc blood volume and flow of POAG patients reduced from 27.1 and 545.4 to 22.3 and 452.4 after cold provocation test (Plt;0.05),and increased to 29.0 and 579.5 after nifedipine adminstration(Plt;0.05).The changes of mean optic disc blood flow of patients with a history of cold extremities show statistic significance compared with whom without such history (Plt;0.05)). Conclusion The changes of blood flow of optic disc in POAG patients may be influenced by cold stimuli and administration of nifedipine,and the history of cold extremities might be connected with the change of optic disc blood flow in POAG patients. (Chin J Ocul Fundus Dis,2000,16:85-87)
OBJECTIVE:To evaluate the therapeutic effect of acetazolamide treatment on chronic cystoid macular edema (CME). METHODS:Thirty-seven patients (40 eyes)with documented chronic CME of various causes were prospectively treated for 4-week periods with acetazolamide or a placebo in a randomised,crossover study that compared their effects on the reduction of macular edema and improvement of visual functions. Central retinal artery(CRA) blood flow was determined using Doppler velocimetry and vessel diameter measurement using computerised digital image analysis of monochromatic fundus photographs on 10 patients (12 eyes)with CME pre-and post-administration of acetazolamide. RESULTS:More than half the patients showed a response to acetazolamide with partial or complete resolution of. edema. Thirty eyes had improved in visual acuity in the treated patients. Statistically significant improvement were seen in 10deg; thresholds of visual field and ERG b wave amplitude. No improvement was seen when the patients received placebo. There were significant increase of blood flow velocity in CRA and retinal vessels diameter after acetazolamide were administered 3 hours later in CME patients (Plt;0.05). CONCLUSION: Acetazolamide could be of value in reducing the degree of edema and improving visual function to chronic CME. The improvement on retinal circulation might be a major cause to limit the CME. （Chin J Ocul Fundus Dis,1997,13: 89-92）
Objective To investigate the biological mechanism about autologous peripheral blood stem cell transplantation （ABSCT） derived neovascularization to lead and perfect the effect of ischemic state tissue of secondary blood flow remodeling. Methods Forty-two patients with critical limbs ischemia and 42 limbs in all from Mar. 2005 to Dec. 2005 in Yunnan Provincial Center of Vascular Surgery were selected，who treated by endovascular repair and ABSCT at the first flow reconstruction and the secondary flow reconstruction，respectively. The preoperative and postoperative effect degrees of limbs regional blood flow from cutaneous covering，blood vessel，and blood were measured by multifunction monitoring device，dopplor ultrasound monitoring device，percutem oxygen partial pressure （TcPO2）monitoring device and digital subtraction angiography （DSA）. The follow-up time was in four year after ABSCT.Results After ABSCT， the pain，cold or cool，and rest pain of leg were relieved. The distance of intermittent claudication after ABSCT was longer than that before ABSCT 〔（1 600.3±310.1） m versus （520.3±160.6） m，F=5.84，P＜0.05〕. The foot pain and limbs insensible feeling easement rates were 100% after ABSCT. Compared with beforeABSCT，the objective effect indexes of limbs regional blood flow after ABSCT were significantly improved 〔skin temperature index：1.63±0.31 versus 1.22±0.23，F=4.69，P＜0.05； TcPO2： （37.61±9.52） mm Hg versus （30.63±4.54） mm Hg，F=5.72，P＜0.05；ankle-brachium index：0.93±0.23 versus 0.33±0.24，F=6.72，P＜0.05；photoplethysmography index：0.81±0.12 versus 0.23±0.05，F=5.68，P＜0.05；saturation of blood oxygen： （79.44±20.42）% versus （42.43±10.41）%，F=5.68，P＜0.05； DSA score：1.34±0.23 versus 0.21±0.03，F=4.89，P＜0.05〕. Conclusions The results bly suggest that the ABSCT can promote blood flow remodeling in limbs ischemia，and stem cells derived neovascularization can significantly offer effective and permanent blood flow perfusions to the ischemic statetissue，and this biological effect play an important role in the ischemic state tissue for secondary blood flow remodeling.
As an innovative training method, blood flow restrictive exercise has gradually received extensive attention and application in rehabilitation medicine in recent years. Blood flow restrictive exercise can be combined with low-load, low-intensity training to promote individual muscle hypertrophy and enhance muscle strength to prevent muscle atrophy, which provides an alternative for those who cannot perform high-load, high-intensity training. However, the clinical use strategy and clinical application effect of blood flow restriction exercise are still unclear. This article will mainly introduce the operation methods, use risks, and application methods of blood flow restrictive exercise, in order to provide a reference for the clinical application and research of blood flow restrictive exercise.
ObjectiveTo observe the changes of retinal and choroidal blood flow density and thickness in macula of different myopic dioptre eyes, and to analyze the correlation between retinal and choroidal blood flow density and axial length (AL). MethodsA retrospective clinical study. From October 2022 to May 2023, 86 eyes of 56 myopic patients scheduled for refractive surgery in Hubei Clinical Center of Laser Ophthalmopathy were included into the study. According to the equivalent spherical specular degree (SE), 19, 21, 27 and 19 eyes of low myopia group (group A), moderate myopia group (group B), high myopia group (group C) and super high myopia group (group D) were observed. Optical coherence tomography angiography (OCTA) and AL measurement were performed in all patients. The diopter was expressed in SE. AL was measured by ultrasonic bio-meter. OCTA scanner was used to scan the macular region in the range of 3 mm × 3 mm. The software automatically divided the macular region into two concentric circles with the fovea as the center, which were 1 mm in diameter respectively, the paracentric fovea of 1-3 mm was divided into 5 regions: superior, nasal, inferior and temporal. The superficial capillary plexus (SCP), deep capillary plexus (DCP), choroidal capillary plexus (CC), choroidal blood flow density, retinal and choroidal thickness were measured. The correlation between AL and blood flow density and thickness was analyzed by Pearson correlation analysis. ResultsThere was no significant difference in SCP blood density and DCP blood density in the fovea in groups A, B, C and D (P＞0.05) .There were significant differences in DCP flow density among superior, nasal, inferior and temporal areas (P＜0.05), the difference was significant (P＜0.05). There was no significant difference in the fovea area between the four groups (P＞0.05), but there was significant difference in the superior, nasal, inferior and temporal areas (P＜0.05). Different macular regions: there were statistically significant among group A, group B, and group C, group D (P＜0.05). Results of correlation analysis, AL was negatively correlated with DCP blood flow density (r=－0.504, －0.500, －0.460, －0.465), retinal thickness (r=－0.348, －0.338, －0.312, －0.230), macular Subarea CC (r=－0.633, －0.666, －0.667, －0.710, －6.82), choroidal layer (r=－0.635, －0.687, －0.659, －0.703, －0.680) and choroidal thickness (r=－0.665, －0.605, －0.656, －0.648, －0.643) (P＜0.05). ConclusionsAL is negatively correlated with DCP, CC, CDF, retinal and choroidal thickness in the eyes with myopia. SCP, DCP and retinal thickness in fovea did not change significantly, and temporal choroidal thickness changed earlier than other areas.