Lower Limb Blood Flow Research Articles

Comparing BlueDop Vascular Expert to ankle-brachial index in the identification of peripheral vascular disease in all-comers and diabetic patients

ObjectiveWe compared the screening capabilities of the BlueDop Vascular Expert (BVE) and ankle-brachial index (ABI) in peripheral arterial disease for all-comer patients and those with diagnosed diabetes mellitus (DM). MethodsData were collected retrospectively and prospectively at a single center in 104 all-comers from BVE and ABI compared with conventional full leg arterial duplex on the same patient, same limb, and at the same appointment. A final comparison was made between the BVE and ABI using full leg arterial duplex as the diagnostic comparison. 104 all-comers were included, and 35 of those patients had diagnosed DM. ResultsFor all-comers, BVE sensitivity was 90%, specificity was 96%, accuracy was 94.5%, and κ = 0.84. In contrast, ABI sensitivity was 53%, specificity was 95%, accuracy was 86%, and κ = 0.53. Of the 35 patients with DM, BVE screened 65 limbs and ABI screened 63 limbs. For patients with DM, BVE sensitivity was 90%, specificity was 98%, accuracy was 95.4%, and κ = 0.89. In contrast, ABI sensitivity was 40%, specificity was 81%, accuracy was 68.3%, and κ = 0.23. ConclusionsThe need for a device that is easy to use, easy to interpret, portable, and, most important, accurate, is critical in reducing long-term complications of peripheral artery disease. As a cuffless arterial assessment system, the BVE was found to have superior sensitivity, specificity, and accuracy when compared with ABI in all-comers. In patients with DM, BVE also showed greater sensitivity, specificity, and notably an accuracy of 95.4% compared with ABI's accuracy of 68.3%. The data support that BVE is an accurate and easy-to-use lower limb blood flow assessment device, even when assessing the most challenging patients.

Feasibility and effectiveness of a foam rolling intervention in pregnant women requiring bed rest for foetal protection: a randomised controlled trial

BackgroundBed rest during pregnancy can lead to reduced physical activity, impairing lower limb venous blood flow and increasing the risk of deep vein thrombosis (DVT) and muscle atrophy. We investigated the clinical efficacy of foam rolling intervention (FRI) in enhancing lower limb venous blood flow, mitigating the risk of DVT and muscle atrophy in pregnant women on bed rest.MethodsThis single-blind, randomised controlled trial enrolled 86 pregnant women with long-term bed rest for foetal protection (≥ 7 days), gestational age ≥ 20 weeks, and maternal age < 40 years. Participants were randomly assigned to a control or experimental group using a random number table. The control group received standard care, whereas the experimental group underwent FRI. Researchers and statisticians were aware of the treatment groups, however, the participants were blinded. Lower limb blood flow velocity, D-dimer levels, incidence of DVT, and the extent of lower limb muscle atrophy were assessed in both groups at baseline and post-intervention (day 7). To account for a 5% attrition rate and potential sampling error, the estimated sample size for each experimental and control group was 40.ResultsBefore the intervention, no significant differences were observed between the experimental and control groups in peak blood flow, mean flow velocity, D-dimer values, or leg circumference (P > 0.05), however, the peak blood velocities of the popliteal veins were significantly higher in the control group (P = 0.031). On the seventh day post-intervention, the experimental group had significantly higher mean and peak blood velocities in femoral and popliteal veins, significantly (P < 0.05), lower mean D-dimer levels (P = 0.035), and a significantly smaller reduction in thigh and calf circumference (P < 0.001). Consequently, the rate of thigh muscle atrophy was significantly slower in the experimental group (P = 0.011).ConclusionsFRI is an effective intervention for improving lower limb venous blood flow, mitigating the risk of DVT and muscle atrophy in pregnant women on bed rest.Trial registrationThis trial was retrospectively registered with the Chinese Clinical Trial Registry on June 18, 2024 (registration number: ChiCTR2400085770).

Resistance exercise breaks during prolonged sitting augment the blood flow response to a subsequent oral glucose load in sedentary adults.

Sitting-induced impairments in postprandial blood flow are an important link between sedentary behaviour and cardiometabolic disease risk. The objective of this work was to examine the effects of resistance exercise breaks (REB) performed every 30min during an otherwise sedentary 3-h period on the vasodilatory response to a subsequent oral glucose load in sedentary adults. Twenty-four sedentary adults (27±7 years, 16 females) completed two conditions.Fasting blood glucose, insulin, popliteal artery blood flow (PABF) and gastrocnemius perfusion were measured immediately before standardized breakfast consumption. After breakfast, the 3-h REB or uninterrupted (SIT) intervention period commenced. Participants sat at a workstation, and popliteal artery shear rate (PASR) was measured 60 and 120min into this period. In the REB condition, participants performed a 3-min REB (3 × [20s squats, 20s high knees, 20s calf raises]) every 30min. Following the intervention period, baseline measurements were repeated. Participants then consumed a 75g glucose beverage, and PABF and perfusion were measured every 30-60min for the following 120min. Relative to SIT, REB increased PASR at 60min (+31.4±9.2/s, P=0.037) and 120min (+37.4±10.2/s, P=0.019) into the intervention period. Insulin and glucose increased (P<0.001) in response to glucose consumption, with no differences between conditions (P≥0.299). In response to the glucose load, perfusion (1.57vs. 1.11mL/100mL/min, P=0.023) and PABF (+45.3±11.8mL/min, P=0.001) were greater after REB versus SIT. Performing 3-min REB every 30min during an otherwise sedentary 3-h period augmented leg blood flow responses to an oral glucose load. HIGHLIGHTS: What is the central question of this study? Can 3-min resistance exercise breaks (REB) performed during an otherwise sedentary 3-h period augment the vasodilatory response to a subsequent oral glucose load in sedentary adults? What is the main finding and its importance? Performing 3-min REB, which included squats, high knees, and calf raises, every 30min augmented lower limb blood flow responses to a subsequent oral glucose load compared to 3h of uninterrupted sitting in sedentary adults. Sitting-induced impairment in postprandial vasodilatory function has been identified as a link between sedentary behaviour and cardiometabolic disease. Thus, the current study presents a potentially effective strategy to offset this risk.

Allograft Model of Aortic Arch Segment Grafting to Abdominal Aorta Through End-to-Side Anastomosis in Mice

The mouse aortic transplantation model is a valuable tool for investigating the mechanisms of atherosclerosis regression, but few laboratories can generate it due to the operation difficulty, especially for the style of end-to-side anastomosis, which facilitates syngeneic heterotopic transplanting a plaque-rich aortic arch into the abdominal aorta. Here we provide a modified protocol for generating this allograft model, which is capable of overcoming several critical surgical challenges such as separating a longer abdominal aorta segment, reducing bleeding and thrombosis, optimizing aortotomy, and improving end-to-side anastomosis to guarantee a potent graft. By transplanting plaque-rich aortic arches into the abdominal aorta of wildtype mice, a high operation success rate (over 90%) was noted with aortic clamping time under 60 min, the graft potency was satisfactory evidenced by examinations of micro-CT, ultrasound, and lower limb blood flow measurement, while a significant atherosclerosis regression was observed in the grafts at 1 week after transplantation.Graphical

Lower limb blood flow occlusion increases systemic pressor response without increasing brachial arterial blood flow redistribution in women.

This study was conducted to investigate the systemic hemodynamic and vascular changes in women during and after two commonly used clinical blood flow restriction (BFR) pressures at rest. There are minimal data regarding the independent effects of BFR on hemodynamic and systemic vascular changes due to pressor response, particularly among women. Therefore, this study investigated BFR-induced alterations in pressor response and systemic flow redistribution at rest during two commonly used pressures (50% and 80% limb occlusion pressure [LOP]). Fifteen women (22.1 ± 4.2 years) completed two randomised sessions involving 8-min of bilateral, lower limb restriction at 50% or 80% LOP followed by 8-min of recovery post-deflation. Changes in vascular (arterial diameter [DIA], time-averaged mean velocity [TAMV], volume flow [VF], and area) and hemodynamic (heart rate [HR] and blood pressure) measures over time (pre-, during, post-occlusion) and by session (50% vs. 80% LOP) were tested using repeated measures analysis of variance. Repeated measures correlations (rrm) quantified common intraindividual associations between BFR-induced hemodynamic and vascular responses. HR increased from baseline during 50% LOP and remained elevated during recovery (p < 0.05). HR increased from baseline during 80% LOP, while tibial VF and TAMV decreased (p < 0.03 for all). HR and TAMV values returned to baseline during recovery, while brachial artery VF decreased (p < 0.05). Changes in HR, brachial VF, and brachial TAMV were similar between 50% and 80% LOP (rrm = 0.32-0.70, p < 0.05 for all). At 80% LOP, changes in HR were positively correlated with brachial VF (rrm = 0.38) and TAMV (rrm = 0.43) and negatively correlated with tibial VF (rrm = -0.36) and TAMV (rrm = -0.30) (p < 0.05 for all). Results suggest that BFR at 80% LOP elicits an acute systemic pressor reflex without concomitant increases in brachial arterial flow, while 50% LOP elicits a subdued response.

A rat model for acute limb ischemia using microsized gelatin beads.

Acute limb ischemia (ALI) is a rapid decrease in lower limb blood flow due to acute occlusion of peripheral arteries or bypass grafts. This study aimed to establish an ALI model using microsized gelatin beads and to investigate the pathophysiological conditions. Male Sprague-Dawley rats were anesthetized, and a low or high dose of microsized gelatin beads was administered into the left femoral artery on days 0 and 7. A control, that is, normal saline (NS) group in which NS was administered in the left femoral artery, a femoral artery cut (FAC) group in which the left femoral artery was cut, and a sciatic nerve cut (SNC) group in which the left sciatic nerve was cut were prepared. After 21 days, the temperature changes and the muscle weights in the lower limbs were measured. To assess nerve damage, the L1-6 sympathetic ganglia were immunostained with activating transcription factor 3 (ATF3) antibody. In the Low-dose, High-dose, and FAC groups, a decrease in temperature was predominantly observed in the left limb. In the High-dose and SNC groups, the weight of the soleus muscle and extensor digitorum longus in the left limb decreased; however, no weight changes were observed in the Low-dose and FAC groups. Conversely, the weight of the gastrocnemius muscle significantly decreased in the Low-dose, High-dose, FAC, and SNC groups. In the High-dose and SNC groups, the number of ATF3-positive cells in the sympathetic ganglia significantly increased, and in the Low-dose, a small number of ATF3-positive cells were observed. However, ATF3-positive cells were rarely observed in the FAC and NS groups. We established an ALI rat model using microsized gelatin beads. The results of this study suggest that autonomic neuropathy in ALI is related to both muscle damage and peripheral neuropathy.

Employing Deep Reinforcement Learning to Maximize Lower Limb Blood Flow Using Intermittent Pneumatic Compression.

Intermittent pneumatic compression (IPC) systems apply external pressure to the lower limbs and enhance peripheral blood flow. We previously introduced a cardiac-gated compression system that enhanced arterial blood velocity (BV) in the lower limb compared to fixed compression timing (CT) for seated and standing subjects. However, these pilot studies found that the CT that maximized BV was not constant across individuals and could change over time. Current CT modelling methods for IPC are limited to predictions for a single day and one heartbeat ahead. However, IPC therapy for may span weeks or longer, the BV response to compression can vary with physiological state, and the best CT for eliciting the desired physiological outcome may change, even for the same individual. We propose that a deep reinforcement learning (DRL) algorithm can learn and adaptively modify CT to achieve a selected outcome using IPC. Herein, we target maximizing lower limb arterial BV as the desired outcome and build participant-specific simulated lower limb environments for 6 participants. We show that DRL can adaptively learn the CT for IPC that maximized arterial BV. Compared to previous work, the DRL agent achieves 98% ± 2 of the resultant blood flow and is faster at maximizing BV; the DRL agent can learn an "optimal" policy in 15 minutes ± 2 on average and can adapt on the fly. Given a desired objective, we posit that the proposed DRL agent can be implemented in IPC systems to rapidly learn the (potentially time-varying) "optimal" CT with a human-in-the-loop.

MEDICINAL BIOMAGNETISM FOR PAIN RELIEF IN VASCULAR ALTERATIONS - APPLICATION OF STATIC MAGNETIC FIELDS THROUGH THE PROTOCOL FOR BLOOD FLOW IN LOWER LIMBS

Introduction: Chronic Venous Insufficiency (CVI) is a set of clinical manifestations resulting from the chronic dysfunction of the peripheral venous system that affects the lower limbs. There is a growing search for complementary therapies, such as Medicinal Biomagnetism (MB), which acts in a non-invasive, painless, low-cost and with rare contraindications, aiming to improve quality of life. MB uses Static Magnetic Fields (SMF) to restore bioenergetic balance and promote health, including CVI. Objective: The aim of this study is to evaluate the effect of SMF application, through the MB Lower Limb Blood Flow Protocol (LLBFP), on pain resulting from vascular alterations of the lower limbs. Methodology: This is a cross-sectional clinical experimental study in three female participants with vascular alterations in the lower limbs who underwent the LLBFP Protocol. Pain, edema and quality of life complaints were assessed using the Venous Insufficiency Epidemiological and Economic Study (VEINES), Visual Analogue Scale (VAS), and perimeter measurements questionnaires, before and after the application of the LLBFP. Results: After treatment with the LLBFP Protocol, there was a trend towards the analgesic effect and reduction of edema, as well as improvement in the aspects related to the symptoms of heavy, restless, tired legs, and tingling, burning and itching, promoting improvement in quality of life. Conclusion: This study demonstrated that the application of the MB LLBFP Protocol has the potential to reduce the subjective perception of pain and edema in lower limbs with vascular alterations. The magnets used in the LLBFP may promote an anti-inflammatory response, contributing to the improvement of quality of life.

Blood flow restriction training improves the efficacy of routine intervention in patients with chronic ankle instability

As a new means of rehabilitation, blood flow restriction training (BFRT) is widely used in the field of musculoskeletal rehabilitation. To observe whether BFRT can improve the efficacy of routine rehabilitation intervention in patients with chronic ankle instability (CAI). Twenty-three patients with CAI were randomly divided into a routine rehabilitation group (RR Group) and a routine rehabilitation ​+ ​blood flow restriction training group (RR ​+ ​BFRT Group) according to the Cumberland Ankle Instability Tool (CAIT) score. The RR Group was treated with routine rehabilitation means for intervention, and the RR ​+ ​BFRT Group was treated with a tourniquet to restrict lower limb blood flow for rehabilitation training based on routine training. Before and after the intervention, the CAIT score on the affected side, standing time on one leg with eyes closed, comprehensive scores of the Y-balance test, and surface electromyography data of tibialis anterior (TA) and peroneus longus (PL) were collected to evaluate the recovery of the subjects. Patients were followed up 1 year after the intervention. After 4 weeks of intervention, the RR ​+ ​BFRT Group CAIT score was significantly higher than the RR Group (19.33 VS 16.73, p ​< ​0.05), the time of standing on one leg with eyes closed and the comprehensive score of Y-balance were improved, but there was no statistical difference between groups (p ​> ​0.05). RR ​+ ​BFRT Group increased the muscle activation of the TA with maximum exertion of the ankle dorsal extensor (p ​< ​0.05) and had no significant change in the muscle activation of the PL with maximum exertion of the ankle valgus (p ​> ​0.05). There was no significant difference in the incidence of resprains within 1 year between the groups (36.36% VS 16.67%, p ​> ​0.05). The incidence of ankle pain in the RR ​+ ​BFRT Group was lower than that in the RR Group (63.64% VS 9.09%, p ​< ​0.01). Therefore, four-weeks BFRT improves the effect of the routine intervention, and BFRT-related interventions are recommended for CAI patients with severe ankle muscle mass impairment or severe pain.

Acute upper and lower limb hemodynamic responses during single sessions of low- versus high-intensity inspiratory muscle strength training.

Inspiratory muscle strength training (IMST) has shown potential to improve both respiratory and cardiovascular function in health and disease. Less is known about acute hemodynamic responses to a single IMST session, therefore we assessed upper and lower limb blood flow via Doppler ultrasound in the brachial and popliteal arteries, respectively. Mean, anterograde, and retrograde blood flow (BF) and shear rate (SR) were assessed relative to baseline during low-intensity (15% maximal inspiratory pressure - PImax) and high-intensity (75% PImax) IMST. During low-intensity IMST, popliteal BF and SR were reduced by ∼10%, and brachial BF and SR were reduced by ∼40%. During high-intensity IMST, popliteal BF and SR were reduced by ∼20%, and brachial BF and SR were reduced by ∼35%. BF and SR responses were not statistically different between low-intensity and high-intensity training for either blood vessel (P > 0.05). In addition, anterograde BF and SR were significantly decreased in the brachial artery for both low-intensity and high-intensity training (P < 0.05), but not the popliteal artery (P > 0.05). Finally, during IMST retrograde BF and SR were significantly increased in both the upper and lower limbs during low-intensity and high-intensity training (P < 0.05). These data provide novel insight into the acute BF and SR responses to a single bout of IMST and may enhance our understanding of the mechanism(s) by which IMST imparts its beneficial chronic effects on cardiovascular function.NEW & NOTEWORTHY Herein, we demonstrate for the first time that upper and lower limb blood flow and shear rate patterns are altered during a single bout of IMST, at low- and high-intensity training. Specifically, anterograde blood flow and shear rate are significantly reduced in the brachial artery, whereas retrograde blood flow is significantly elevated in both the brachial and popliteal arteries. These findings provide insight into the vascular impact of IMST, which may inform future mechanistic studies.

Comparison Between the Efficacy of Spinal Cord Stimulation and of Endovascular Revascularization in the Treatment of Diabetic Foot Ulcers: A Retrospective Observational Study

ObjectiveWe aimed to compare the effects of spinal cord stimulation (SCS) with those of endovascular revascularization on the treatment of diabetic foot ulcers. Materials and MethodsA total of 104 patients with diabetic foot ulcers who met the inclusion criteria were retrospectively analyzed and classified to the SCS treatment group (n = 46) and endovascular revascularization treatment group (n = 46). The quality-of-life scores (Quality of Life Scale for Patients with Liver Cancer v2.0), visual pain analog scale score, lower limb skin temperature, lower limb arterial ultrasound results, and lower extremity electromyography results were analyzed to compare the efficacy of the two treatments for diabetic foot ulcers in the two groups before surgery and six months after surgery. ResultsA total of 92 patients (men: 73.9%, mean age: 66.51 ± 11.67 years) completed the six-month postoperative follow-up period. The patients in the SCS treatment group had a higher quality-of-life score (25.54% vs 13.77%, p < 0.05), a larger reduction in pain scores (69.18% vs 37.21%, p < 0.05), and a larger reduction in foot temperature (18.56% vs 7.24%, p < 0.05) than those of the endovascular revascularization treatment group at six months after surgery. The degree of vasodilation in the lower limbs on color Doppler arterial ultrasound and the nerve conduction velocity were higher in the SCS treatment group than in the endovascular revascularization treatment group at six months after surgery (p < 0.05). ConclusionSCS was more effective than endovascular revascularization in improving quality of life, relieving pain, improving lower limb skin temperature, increasing lower limb blood flow, and improving nerve conduction in patients with diabetic foot ulcers at six months after surgery.

RSO2 Measurement Using NIRS for Lower-Limb Blood Flow Monitoring and Estimation of Safe Balloon Occlusion/Deflation Time in Patients with PAS Who Underwent PBOA during CS.

We examined the utility of regional oxygen saturation (rSO2) measurement using near-infrared spectroscopy (NIRS) for monitoring lower-limb blood flow and estimate the safe balloon occlusion/deflation time in patients with PAS who underwent prophylactic balloon occlusion of the abdominal artery (PBOA) during cesarean section (CS). During CS, the NIRS probes were positioned on either of the anterior tibial muscles. rSO2 was measured continuously during balloon occlusion/deflation. A cycle consisted of inflating the aortic balloon for 30 min and deflating it for 5 min. The rSO2 before/during balloon occlusion and after 5 min of balloon deflation were evaluated. Sixty-two lower limbs (fifteen women and data from 31 sessions of balloon inflation/deflation) were evaluated. rSO2 during balloon occlusion was significantly lower than rSO2 before balloon occlusion (57.9% ± 9.6% vs. 80.3% ± 6.0%; p < 0.01). There were no significant differences between rSO2 before balloon occlusion and rSO2 after 5 min of balloon deflation (80.3% ± 6.0% vs. 78.7% ± 6.6%; p = 0.07). Postoperatively, the lower limbs showed no ischemic symptoms. NIRS can assess lower-limb rSO2 during PBOA for PAS in real time to determine ischemia severity, duration, and recovery capacity.

Understanding lower limb blood flow occlusion parameters for use in field-based settings

ABSTRACT Reduction of blood flow to the limb using cuffs before or during exercise has become increasingly popular for training and rehabilitation. Our study tested the effects of cuff brand/width on pressures required to reach limb occlusion pressure (LOP) and developed, cross-validated, and compared accuracy of two LOP prediction equations to previously created methods. Supine LOP was determined in the distal popliteal artery using four different cuff brands/widths in 23 adult participants. Participants then had demographic and resting variables assessed, and two LOP prediction equations were developed from these variables and were compared to five previously developed models and a method using posterior tibial artery palpation for LOP assessment in an independent sample (n = 14 adult runners). For cuff comparison, the widest two cuffs had significantly lower LOP (mean ~149 mmHg) than the narrowest cuffs (mean ~176 mmHg), with the narrowest cuff unable to reach LOP. The eight methods used to predict LOP ranged in accuracy (mean absolute percent errors 3.9–23.0%), with highest accuracy in equations using mean arterial pressure (MAP) and BMI. Practitioners using blood flow reduction methods should be consistent with cuff use due to demonstrated differences across brands/widths. Equations using MAP and BMI appear best for prediction of leg LOP.

Utility of thermographic evaluation in spinal cord stimulation therapy DTM workflow for thoracolumbar compression fracture and lumbar spinal canal stenosis

Among the orthopedic conditions that cause low back pain, many patients with thoracolumbar compression fractures and lumbar spinal canal stenosis caused by osteoporosis visit orthopedic surgeons. However, many patients do not respond to analgesics or nerve block injections, and many are at risk or unwilling to undergo surgery due to age or underlying disease. We believe that spinal cord stimulation therapy is a new treatment option for orthopedic low back and leg pain. We have performed spinal cord stimulation for chronic intractable pain in patients with thoracolumbar spine compression fractures and lumbar spinal canal stenosis who had lower limb pain and back pain. There are few reports of spinal cord stimulation therapy treatment by orthopedic surgeons. In many cases, medical medications and nerve blocks do not improve the pain, and surgical treatment may be performed. We evaluated whether minimally invasive spinal cord stimulation therapy for orthopedic diseases improves pain by altering blood flow to the lower extremities using thermography. Methods: Thermography and NRS of both lower extremities were measured before and after spinal cord stimulation therapy in 27 patients (15 women and 12 men) with back and leg pain due to thoracolumbar spine compression fracture and lumbar spinal canal stenosis. Results: Thermography showed an increase in body surface temperature of approximately 6°C. NRS showed an average improvement of 6.4. Discussion: Spinal cord stimulation therapy may improve blood flow in both lower limbs and lower back and leg pain, especially for back and leg pain caused by thoracolumbar vertebral compression fracture and lumbar spinal canal stenosis, among other orthopedic diseases. Thermography is likely to be useful as an evaluation tool.

Chopart amputation with tendon balancing.

When foot necrosis occurs due to lower limb blood flow disorder caused by diabetes or peripheral arterial occlusion, many patients require lower limb amputation. The functional prognosis after lower limb amputation largely depends on whether the heel can be preserved. However, there are many reports that Chopart amputation causes varus and equinus deformity, and is functionally unfavorable. We herein report a case of Chopart amputation performed with muscle balancing. Postoperatively, the foot was not deformed and the patient was able to walk independently with a foot prosthesis. A 78-year-old man presented with ischemic necrosis of his right forefoot. The range of necrosis extended to the central part of the sole, so Chopart amputation was performed. In the operation, to prevent varus and equinus deformity, the Achilles tendon was lengthened, the tibialis anterior tendon was transferred through a tunnel created in the neck of talus, and the peroneus brevis tendon was transferred through a tunnel created in the anterior part of the calcaneus. At the final follow-up 7 years after the operation, no varus or equinus deformity was observed. The patient became able to stand up and walk on his heel without a prosthesis. In addition, step motion was possible by wearing a foot prosthesis.

Acceptable Intra-aortic Balloon Occlusion Duration Affecting the Regional Saturation Oxygen of Lower Limbs Using Near-infrared Spectroscopy for Abnormally Adherent Placentation

Objective: To investigate the utility of regional saturation oxygen (rSO2) using near-infrared spectroscopy (NIRS) in the lower limbs and to estimate the safe occlusion duration in patients with abnormally adherent placentation who underwent intra-aortic balloon occlusion (IABO) during a cesarean hysterectomy by comparing them with infrarenal aortic clamping. Methods: The researchers classified 15 lower limbs of patients with abnormally adherent placentation with IABO during a cesarean hysterectomy as the balloon group and 20 lower limbs of patients with cross-clamping on the infrarenal aorta during the aneurysmal repair as the clamping group. The rSO2 measurement of the limbs was performed using a near-infrared spectrometer. In addition, the aortic occlusion duration, rSO2 before and during occlusion, and after blood resumption were analyzed. Results: Continuous rSO2 measurement was possible in all patients. The median aortic occlusion durations in the balloon and clamping groups were 68 and 92.5 min, and the median minimum rSO2 during occlusion was 60% and 17.5%, respectively. The clamping group was found to have stronger occlusion for a longer time than the balloon group. No complications associated with aortic occlusion were observed in both groups. Conclusions: rSO2 measurement using a near-infrared spectrometer effectively monitors lower-limb blood flow during IABO in patients with abnormally adherent placentation. An IABO duration of approximately 90 min was believed to be relatively acceptable in a cesarean hysterectomy under heparin administration.

CircCRIM1 Ameliorates Endothelial Cell Angiogenesis in Aging through the miR-455-3p/Twist1/VEGFR2 Signaling Axis.

Background Aging leads to vascular endothelial cell senescence. Decreased expression of VEGFA and VEGFR2 plays a crucial role in impairing angiogenesis in senescent endothelial cells. Noncoding RNAs, including circular RNAs (circRNAs) and microRNAs (miRNAs), regulate endothelial cell proliferation, differentiation, apoptosis, and migration and participate in the occurrence and development of vascular diseases. However, the mechanism of noncoding RNAs in age-related vascular endothelial dysfunction remains unclear. Here, we aimed to identify the circRNA that is associated with VEGF/VEGFR2 signaling pathway activation in angiogenesis. Methods Immunoblotting, quantitative reverse transcription-polymerase chain reaction (qRT–PCR), in vitro and in vivo experiments, luciferase assays, and chromatin immunoprecipitation followed by qRT–PCR (ChIP–qPCR) assays were performed to clarify the roles played by circCRIM1 in mouse aortic endothelial cell (MAEC) angiogenesis. Results CircCRIM1 expression was downregulated in both an aging mouse model of lower limb ischemia in vivo and aging MAECs in vitro. Overexpressing circCRIM1 mediated through a plasmid or adeno-associated virus (AAV) reversed the downregulation of angiogenesis-related phenotype acquisition during aging. MiR-455-3p was confirmed to be a potential target of circCRIM1 through luciferase assays followed by RNA fluorescence in situ hybridization (FISH), which revealed the colocalization of circCRIM1 and miR-455-3p. CircCRIM1 was found to be a competitive endogenous RNA that sponged miR-455-3p and regulated angiogenesis-related phenotypes in MAECs. Furthermore, Twist1 was found to be downstream of miR-455-3p. A ChIP–qPCR assay showed that Twist1 promoted VEGFR2 expression by binding to the promoter region, playing a vital role in angiogenesis. Conclusions Decreased expression of circCRIM1 impaired angiogenesis in aging via the miR-455-3p/Twist1/VEGFR2 axis. Our findings suggest that overexpression of circCRIM1 may be an effective therapeutic strategy for promoting ischemic lower limb blood flow recovery.

Ruan Jian Qing Mai Recipe Inhibits the Inflammatory Response in Acute Lower Limb Ischemic Mice through the JAK2/STAT3 Pathway.

Ruan jian qing mai recipe (RJQM) is an empirical prescription for treating arteriosclerosis obliterans (ASO). However, the mechanism of RJQM recipe-mediated ASO attenuation has not yet been elucidated. Therefore, this study aimed to explore the mechanism by which the RJQM recipe relieves ASO in a mouse model of lower limb ischemia, which was established by ligating and breaking the femoral artery of the left lower limb. The surgical groups were divided into the ischemic group, beraprost sodium group, low-dose RJQM group, medium-dose RJQM group, and high-dose RJQM group. Normal mice were set as the control group. The blood flow of the lower limb was examined on days 7 and 14. At the end of animal procedures, blood samples were collected, and the rectus femoris of the left lower limb were harvested. Results revealed that mice in the ischemic group demonstrated low blood flow. Additionally, hematoxylin and eosin, and Masson staining results showed that inflammation of the rectus femoris was obvious in the ischemia group, and the level of fibrosis was increased. Blood flow was recovered in all treatment groups compared to the ischemic group, and the inflammatory infiltration and fibrosis of the rectus femoris were relieved after RJQM treatment. The serum levels of interleukin (IL)-17A and IL-21 were decreased, and the expression of JAK2/STAT3 proteins was inhibited in all RJQM treatment groups compared to the ischemia group. Furthermore, the improvement of IL-17A, IL-21, and rectus femoris fibrosis was more obvious with increasing treatment time. In conclusion, RJQM can effectively alleviate ASO and promote the recovery of lower limb blood flow by regulating the JAK2/STAT3 signaling pathway to reduce the inflammatory response.

Whole-Body Vibration Associated with Strength Training on the Lower-Limb Blood Flow and Mobility in Older Adults with Type 2 Diabetes: A Study Protocol for a Randomized Controlled Trial.

Vascular endothelium insults caused by high serum glucose levels affect the oxygen supply to tissues, via the microvascular endothelium, resulting in an increased perfusion heterogeneity. These insults may lead to the underuse of blood capillaries, while other vessels are overused and effectively overload their oxygen supply capacity, which eventually causes damages to distal parts of the peripheral nervous system. Therefore, the proprioceptive and exteroceptive feedback information will be gradually lost and contribute to a mobility reduction. This study aims to assess the efficacy of whole-body vibration (WBV) associated with strength training (ST) on lower-limb blood flow and mobility in older adults with type 2 diabetes (DM2). Methods and analyses: This is a protocol (1st version) for Pa single-blind, randomized, controlled clinical trial guided by the SPIRIT guidelines. Our sample will consist of 51 older adults with DM2 randomly allocated to three groups: low frequency WBV (16–26 Hz) associated to ST (G1), WBV sham (G2) and nonintervention control (G3). The study protocol is set for a 12-week (three times per week) schedule. Primary outcomes: skin temperature using infrared thermographic imaging (ITI); mean peripheral arterial blood flow velocity (MBF) by a handheld Doppler ultrasound (DU), and functional mobility by Timed Up and Go (TUG) test. Secondary outcomes: quasi-static posture using the DX100 BTS Smart optoelectronic system, and plantar pressure and body balance using the MPS stabilometric platform. Data will be collected and analyzed at baseline and post-intervention, considering p-value < 0.05 level of significance. The analyses will also be conducted with an intention-to-treat method and effect size. Dissemination: All results will be published in peer-reviewed journals as well as presented in conferences.

Blood Flow Analysis of the Great Saphenous Vein in the Su-Pine Position in Clinical Manifestations of Varicose Veins of Different Severities: Application of Phase-Contrast Magnetic Resonance Imaging Data.

The progression of clinical manifestations of lower-limb varicose veins remains unclear. This study investigated changes in lower-limb venous blood flow using phase-contrast magnetic resonance angiography. Data were collected on veins from 141 legs. We compared legs with and without varicose veins and related symptoms and examined varying levels of varicose vein symptom severity. Legs without varicose veins exhibited a lower absolute stroke volume (ASV, p < 0.01) and mean flux (MF, p = 0.03) for the great saphenous vein (GSV) compared with legs with symptomatic varicose veins. Legs with asymptomatic varicose veins exhibited lower MF for the GSV (p = 0.02) compared with legs with symptomatic varicose veins. Among legs with varicose veins, asymptomatic legs exhibited lower ASV (p = 0.03) and MF (p = 0.046) for the GSV compared with legs that exhibited skin changes or ulcers; however, no significant differences were observed between legs presenting with discomfort or edema and legs with skin changes or ulcers, and between legs presenting with discomfort or edema and asymptomatic legs. In conclusion, in the supine position, increased blood flow rate and blood flow volume in the GSV were associated with symptomatic varicose veins and increased symptom severity.