Lower Extremity Hemodynamics Research Articles

Acute Effects of Skeletal Muscle Electrical Stimulation on Central and Lower Extremity Hemodynamics.

Belt electrode-skeletal muscle electrical stimulation (B-SES) is a treatment prescribed for individuals with difficulty performing exercise therapy that improves muscle strength, exercise tolerance, and glucose metabolism. However, the effects of B-SES on the hemodynamics of the central and lower extremity conduit arteries have not been studied. Therefore, this study compared the acute effects of B-SES on the central and lower extremity conduit arteries in healthy young males. This randomized crossover study included nine healthy young males (mean age: 21.0±1.1 years). Participants were assigned to the following experimental conditions, with a washout period of one week: condition 1 included 20 min of electrical stimulation of the lower extremity at the participant's sensation threshold intensity (Sham, n=9)and condition 2included 20 min of electrical stimulation of the lower extremity at the maximum intensity the participant can tolerate (B-SES, n=9). The heart rate (HR), stroke volume (SV), cardiac output (CO), mean arterial pressure (MAP), and total peripheral vascular resistance (TPR) were measured as central hemodynamics. The hemodynamics of the lower extremity conduit arteries were measured and calculated for the shallow femoral artery (SFA), including vessel diameter, mean blood flow velocity (MBFV), shear rate (SR), and mean blood flow (MBF) rate. These indices were measured before stimulation (Pre), 10 min after the start of stimulation (Stimulating), and immediately after the end of stimulation (Post). These indices were compared using a repeated two-way analysis of variance. In B-SES, HR (Pre: 63.2±8.6; Stimulating: 73.7±6.9; Post: 70.0±4.2 bpm, p<0.01), CO (Pre: 5.1±1.0; Stimulating: 6.5±1.5, p<0.01; Post: 6.3±1.2 L/min, p=0.02), and MAP (Pre: 104.0±11.5; Stimulating: 116.4±10.8, p<0.01; Post: 109.6±9.7 mmHg, p=0.02) increased significantly. In addition, B-SES significantly increased MBFV (Pre: 19.2±4.0; Stimulating: 50.5±14.9; Post: 30.1±4.0 cm/s, p<0.01), SR (Pre: 118.9±28.8; Stimulating: 302.7±91. 2, p<0.01; Post: 182.1±70.1/s, p=0.02), and MBF (Pre: 382.0±61.5; Stimulating: 1009.6±321.4; Post: 626.8±176.6 mL/min, p<0.01). However, there were no significant changes in SV and TPR. The findings of this study indicatethat B-SES in healthy young males increases CO without increasing SV or TPR and improves the MBFV and SR in the SFA.

The effects of different positions on lower extremity hemodynamics during robot-assisted laparoscopic radical prostatectomy for prostate cancer

PurposeThis study aimed to investigate the effects of two different positions on lower extremity hemodynamics during robot-assisted laparoscopic radical prostatectomy (RARP) for prostate cancer.MethodsA total of 196 patients who underwent RARP in our hospital from February 2020 to March 2022 were included in this study. Among them, 98 patients who underwent surgery with the Trendelenburg position and split-leg position with calf reverse arch from March 2021 to March 2022 were assigned to the observation group, while 98 patients who underwent surgery with the Trendelenburg position and low lithotomy position from February 2020 to February 2021 were assigned to the control group. Using an ultrasound diagnostic instrument to detect the internal diameter, mean blood flow velocity, and mean blood flow volume of the left deep femoral vein at different times, such as the supine position (T0), after 5 minutes of placing the patient in the leg spilt or low lithotomy position (T1), after 5 minutes of pneumoperitoneum (T2), after 5 minutes of head-down tilt or head-down tilt and calf reverse arch (T3), 1.5 hours after the start of surgery (T4), before the removal of CO2 gas (T5), and before the patient left the operating room (T6). As well as the patency of deep venous blood flow in both lower extremities before leaving the operating room,ResultsAfter establishment of pneumoperitoneum, the internal diameter of the deep femoral vein increased significantly, while the mean blood flow velocity and mean blood flow volume decreased significantly in both groups(T0) (P<0.001). With the prolongation of surgical time, the impact on lower extremity hemodynamics in the observation group was smaller than that in the control group. From T2 to T6, the internal diameter of the femoral vein in the observation group was smaller than that in the control group, while the mean blood flow velocity and mean blood flow volume were increased compared to the control group (P<0.05). Before leaving the operating room, the patency of deep venous blood flow in the observation group was better than that in the control group (P=0.003).ConclusionPlacing patients in the Trendelenburg position and split-leg position with calf reverse arch during RARP for prostate cancer has a smaller impact on lower extremity hemodynamics than the low lithotomy position, and can relatively reduce the risk of postoperative deep vein thrombosis.

Effects of Enhanced External Counterpulsation With Different Sequential Levels on Lower Extremity Hemodynamics.

Objective: This study aimed to investigate acute hemodynamics of lower extremities during enhanced external counterpulsation with a three-level sequence at the hips, thighs, and calves (EECP-3), two-level sequence at the hips and thighs (EECP-2), and single leg three-level sequence (EECP-1).Methods: Twenty healthy volunteers were recruited in this study to receive a 45-min EECP intervention. Blood flow spectrums in the anterior tibial artery, posterior tibial artery, and dorsalis pedis artery were imaged by Color Doppler ultrasound. Mean flow rate (FR), area, pulsatility index (PI), peak systolic velocity (PSV), end-diastolic velocity (EDV), mean flow velocity (MV), and systolic maximum acceleration (CCAs) were sequentially measured and calculated at baseline during EECP-3, EECP-1, and EECP-2.Results: During EECP-3, PI, PSV, and MV in the anterior tibial artery were significantly higher, while EDV was markedly lower during EECP-1, EECP-2, and baseline (all P < 0.05). Additionally, ACCs were significantly elevated during EECP-3 compared with baseline. Moreover, FR in the anterior tibial artery was significantly increased during EECP-3 compared with baseline (P = 0.048). During EECP-2, PI and MV in the dorsalis pedis artery were significantly higher and lower than those at baseline, (both P < 0.05). In addition, FR was markedly reduced during EECP-2 compared with baseline (P = 0.028). During EECP-1, the area was significantly lower, while EDV was markedly higher in the posterior tibial artery than during EECP-1, EECP-2, and baseline (all P < 0.05). Meanwhile, FR of the posterior tibial artery was significantly reduced compared with baseline (P = 0.014).Conclusion: Enhanced external counterpulsation with three-level sequence (EECP-3), EECP-2, and EECP-1 induced different hemodynamic responses in the anterior tibial artery, dorsalis pedis artery, and posterior tibial artery, respectively. EECP-3 acutely improved the blood flow, blood flow velocity, and ACCs of the anterior tibial artery. In addition, EECP-1 and EECP-2 significantly increased the blood flow velocity and peripheral resistance of the inferior knee artery, whereas they markedly reduced blood flow in the posterior tibial artery.

The Influence of Hip Replacement on Lower Extremity Hemodynamics in Crowe IV Hip Dysplasia Patient

The Influence of Hip Replacement on Lower Extremity Hemodynamics in Crowe IV Hip Dysplasia Patient

Abstract 138: Revascularization Improves the Hemodynamics, Function, and Myopathy of the Legs of Claudicating Patients

Introduction: Patients with claudication due to peripheral artery disease (PAD) have walking and quality of life (QOL) limitations associated with development of ischemic myopathy. Characteristics of PAD-related ischemic myopathy include myofiber degeneration, mitochondrial dysfunction, and oxidative damage. We hypothesize that revascularization operations improve lower extremity hemodynamics, function, and QOL with improvements in key indicators of PAD-related ischemic myopathy. Methods: Patients undergoing open or endovascular revascularization were evaluated before and 6 months after intervention. QOL was assessed by Short Form-36 (SF-36) and Walking Impairment Questionnaire (WIQ). Walking performance was measured by six-minute walking distance (6MWD) and Gardner maximal Treadmill test (Peak Walking Time - PWT). Calf muscle biomechanics were measured by plantar flexor peak force (PFPF) and power generation (PFPG). Limb hemodynamics were measured with Ankle-Brachial Index (ABI) and myopathy was assessed via gastrocnemius biopsy. Myofibers were evaluated for mitochondrial function via respirometry while slide mounted specimens of the gastrocnemius were analyzed for biomarkers of morphology (myofiber cross-sectional area) and myofiber oxidative damage (carbonyl groups) by quantitative fluorescence microscopy. Results: We recruited 52 patients who underwent 34 open and 18 endovascular revascularizations. Average score improved in 7 of 8 SF-36 (p&lt;0.03) and 4 of 4 WIQ categories (p&lt;0.001). PWT and 6MWD increased 305±75s (111.9%, p&lt;0.001) and 62±17M (21.3%, p&lt;0.001) respectively. PFPF and PFPG increased 9.8±3.1N (17.1%, p=0.001) and 1.6±0.08W/Kg (26.9%, p&lt;0.001) respectively. ABI increased from 0.46±0.03 to 0.87±0.03 (90.4%, p&lt;0.001). Myofiber cross-sectional area increased 458±216 μm 2 (11.1%, p&lt;0.05). Complex I-mediated mitochondrial respiration (normalized to citrate synthase activity) improved 8.1±2.8 (15.4%, p&lt;0.01). Oxidative damage observed as carbonyl groups was reduced 132±60 grayscale units (8.0%, p&lt;0.05). Conclusions: Revascularization operations improved the hemodynamics, QOL and leg function of PAD patients in association with improvement in PAD-related ischemic myopathy.

Abstract 726: Intermittent Pneumatic Compression during Hemodialysis to improve Quality of Life in Patients with Peripheral Artery Disease and End Stage Renal Disease

Peripheral artery disease (PAD) is a prevalent global problem with increased mortality. Affects about one in four patients with end stage renal disease (ESRD). Intermittent pneumatic compression (IPC) has shown improvement of lower extremity hemodynamics and symptoms and may be implemented during hemodialysis (HD). We designed a trial to test the utility of IPC in the ESRD population by assessing improvement in quality of life (QOL) and functional limitation from PAD-related symptoms. We aim to present our design and initial results. Methods: This is a prospective single cohort study for paired analysis undergoing recruitment of outpatients at the HD unit of John H. Stroger, Jr. Hospital of Cook County. A sample size of 78 yields a power of 80% and alpha of 0.05, assuming an average peak walking time of five minutes and 25% improvement after supervised exercise. PAD is confirmed by ankle-brachial index (ABI) and demographics collected. A baseline Six-minute Walk Test (6MWT), Peripheral Artery Questionnaire (PAQ) and Walking Impairment Questionnaire (WIQ) are administered and will be compared with their performance post intervention. The IPC device (Bio Arterial Plus) will be used for intervention during each HD for two months average. We present continuous variables as mean±SD and categorical variables as percentage. Results: From 10 recruited patients in the first month, 60% are men, age 54.6±13.1 years, the majority Hispanic (80%). 70% of ABI were abnormal, all due to non-compressible PAD (1.44±0.20). All patients have HTN, 50% diabetes, 20% hyperlipidemia, 10% had a stroke and 10% revascularization for PAD. At baseline 6MWT, distance walked was 357.7±59.5 m, with 600±52.5 total steps and fatigue as main symptom (30%) and no typical claudication. QOL questionnaires showed WIQ walking distance 68.58±18.04, WIQ walking speed 72.5±26.36, and WIQ stair climbing 50.04±30.04 points; PAQ physical limitation 61±21.4, PAQ symptoms 62.79±18.7, PAQ satisfaction 68.67±27.9, PAQ quality of life 64±13.04, and PAQ social limitation 70±23.13 points. Conclusion: Non-compressible PAD is prevalent in ESRD, and QOL seems significantly compromised from it. Our trial will provide insight of an alternative therapy, and optimize the time in HD even further.

Lower Extremity Microembolism in Open vs. Endovascular Abdominal Aortic Aneurysm Repair.

Although previous studies have documented the occurrence of microembolization during abdominal aortic aneurysm (AAA) repair by both open and endovascular approaches, no study has compared the downstream effects of these two repair techniques on lower extremity hemodynamics. In this prospective cohort study, 20 patients were treated with endovascular aneurysm repair (EVAR) (11 Zenith, 8 Excluder, and 1 Medtronic) and 18 patients with open repair (OR) (16 bifurcated grafts, 2 tube grafts). Pre- and postoperative ankle-brachial indices (ABIs) and toe-brachial indices (TBIs) were measured preoperatively and on postoperative day (POD) 1 and 5. Demographics and preoperative ABIs/TBIs were identical in EVAR (0.97/0.63) and OR (0.96/0.63) patients (p = 0.21). There was a significant decrease in ABIs/TBIs following both EVAR (0.83/0.52, p = 0.01) and OR (0.73/0.39, p = 0.003) on POD #1, although this decrease was greater following OR than EVAR (p = 0.002). This difference largely resolved by POD #5 (p = 0.41). In the OR group, TBIs in the limb in which flow was restored first was significantly reduced compared to the contralateral limb (0.50 vs. 0.61, p = 0.03). In the EVAR group, there was also a difference in TBIs between the main body insertion side and the contralateral side (0.50 vs. 0.59, p = 0.02). Deterioration of lower extremity perfusion pressures occurs commonly after AAA repair regardless of repair technique. Toe perfusion is worse in the limb opened first during OR and on the main body insertion side following EVAR, suggesting that microembolization plays a major role in this deterioration. The derangement following OR is more profound than after EVAR on POD #1, but recovers rapidly. This finding suggests that microembolizarion may be worse with OR or alternatively that other factors associated with OR (e.g., the hemodynamic response to surgery with redistribution of flow to vital organs peri-operatively) may play a role.

The effects of modulated medium frequency electrotherapy on lower extremity hemodynamics in perioperative thoracic surgery patients

Objective To evaluate the effects of modulated, medium frequency electrotherapy on hemodynamics after thoracic surgery to provide non-pharmacological measures for preventing deep vein thrombosis (DVT).Methods Seventy thoracic surgery patients were divided into an experimental group and a control group. Both groups received conventional treatment and nursing. The experimental group (35 patients) was treated with modulated, medium frequency electrotherapy additionally while the control group (35 patients) was not. The vein systolic maximum velocity (Vmax), vein diastolic minimum velocity (Vmin) and time-averaged mean velocity (TAVM) in the femoral vein, the superficial femoral vein, the deep femoral vein, the popliteal vein and the anterior tibial vein were observed before the operation, 4h after the operation, just after 20 minutes of electrotherapy, 15 min after the electrotherapy and 30 min after the electrotherapy. Results There were significant differences among the time points in the experimental group. There was no significant difference among the time points in the control group.There were significant differences in lower extremity hemodynamics between the experimental group and the control group at end of the electrotherapy session, but no significant differences at the later time points. Conclusions Modulated, medium frequency electrotherapy has a significant effect on lower extremity hemodynamics. It is an effective method for DVT prophylaxis in perioperative thoracic surgical patients. Key words: Modulated medium frequency electrotherapy; Thoracic surgery; Leg veins; Hemodynamics; Deep vein thrombosis; Prophylaxis

Adjunctive parenteral therapy with lipo-ecraprost, a prostaglandin E 1 analog, in patients with critical limb ischemia undergoing distal revascularization does not improve 6-month outcomes

In patients with critical limb ischemia (CLI), distal revascularization remains the procedure of choice for preventing limb loss, but long-term outcomes for pain relief, wound healing, and prevention of amputation remain suboptimal. Prostaglandin drug therapy as an adjuvant to revascularization may improve these outcomes. The current trial was designed to test the hypothesis that the use of lipo-ecraprost, a lipid encapsulated prostaglandin E(1) prodrug, as an adjunctive therapy after distal revascularization would improve amputation-free survival in patients with CLI. The study was randomized, multicenter, double blind, and placebo controlled. Patients meeting clinical and hemodynamic criteria for CLI who were undergoing either bypass or endovascular revascularization of the below knee popliteal or more distal arteries were randomized to receive placebo or a 60-microg dose of lipo-ecraprost administered intravenously starting <or=72 hours of the index revascularization and then 5 days per week for 8 weeks. The study primary end point was the composite end point of death or amputation at or above the level of the ankle at 180 days. The study randomized 322 patients, and 284 received at least one dose of study medication and were included in the intention-to-treat population. A total of 213 patients underwent surgical bypass, and 71 underwent endovascular revascularization before receiving study medication. The distribution of index revascularization procedures and location of distal target arteries were similar for both placebo and lipo-ecraprost groups. At 180 days, 21 patients (7.4%) were lost to follow-up before reaching the primary end point. Seventy-one percent of the patients taking the placebo completed at least half the doses of the study medication compared with 48% of those taking lipo-ecraprost. Index leg revascularization-assisted primary patency was 82% in the placebo group and 84% in the lipo-ecraprost group (P = .874). Changes in lower extremity hemodynamics as a result of the revascularization during the study period did not differ between the placebo and lipo-ecraprost treatment arms. For the primary event of amputation-free survival, there were no differences between groups: 19 major amputations occurred in the placebo group and 17 in the lipo-ecraprost group; 19 deaths occurred in the placebo group and 13 in the lipo-ecraprost group. Eight weeks of parenteral therapy with lipo-ecraprost after distal revascularization in patients with CLI provided no additional benefit in the reduction of major amputation or death at 180 days.

Parenteral therapy with lipo-ecraprost, a lipid-based formulation of a PGE1 analog, does not alter six-month outcomes in patients with critical leg ischemia

Eicosanoids with vasodilating and angiogenic properties have been postulated to be effective therapies for critical leg ischemia (CLI) secondary to atherosclerotic peripheral arterial disease. The ability to deliver active drug to the site of action at adequate doses for sufficient duration has been a major limitation in the clinical development of such therapies. Lipo-ecraprost is a lipid-encapsulated prostaglandin E1 prodrug with the potential to deliver active prostaglandin to the site of critical arterial ischemia. The current trial was designed to test the hypothesis that lipo-ecraprost would improve amputation-free survival in patients with CLI who had no revascularization options. The study was randomized, multicenter, double blind, and placebo controlled. Patients who met clinical and hemodynamic criteria were randomized to receive placebo or lipo-ecraprost (60 microg) administered intravenously on each of 5 days per week, for a total of 8 weeks. The study's primary endpoint was the rate of a composite end point of death or amputation above the level of the ankle at 180 days (6 months). The study was terminated on a recommendation from the Data and Safety Monitoring Board after the completion of a protocol-specified interim analysis for futility. At the time of termination, 383 of the planned 560 patients had been randomized, of which 379 received at least one dose of study medication and thus were included in the intention-to-treat population. Twenty-three patients were lost to follow-up and were not available for 6-month assessments. At 6 months of follow-up, there were 23 amputations in the 177 patients who received placebo, and 29 amputations in the 179 patients randomized to lipo-ecraprost. At 6 months, 10 deaths had occurred in the placebo group and 18 deaths had occurred in the lipo-ecraprost arm. Changes in lower-extremity hemodynamics over the 6-month study period did not differ between the placebo and lipo-ecraprost treatment arms. Intensive treatment with lipo-ecraprost failed to modify the 6-month amputation rate in patients with CLI who were not candidates for revascularization.

The Effect of Increasing Blood Pressure with Dopamine on Systemic, Splanchnic, and Lower Extremity Hemodynamics in Patients with Acute Liver Failure

Arterial hypotension occurs frequently in patients with acute liver failure (ALF). Treatment with epinephrine and norepinephrine in patients with ALF has been associated with a decrease in whole-body (systemic) oxygen consumption. We aimed to investigate the effect of increasing blood pressure with dopamine on whole-body (systemic), splanchnic, and lower extremity hemodynamics and oxygen consumption in patients with acute liver failure and hepatic encephalopathy grade III or IV. In seven patients with ALF cardiac output (CO) was measured with the thermodilution technique, and hepatic blood flow (HBF) was estimated with infusion of sorbitol as test compound, liver vein catheterization, and calculations on the basis of Fick's principle. Lower-extremity blood flow was measured with strain-gauge plethysmography. During infusion of dopamine (5 +/- 2 microg kg(-1) min(-1)) mean arterial pressure (MAP) increased from 68 +/- 5 to 85 +/- 8 mmHg. CO increased from 6.8 +/- 0.8 to 9.0 +/- 2.4 l/min (P < 0.05), systemic oxygen delivery from 45 +/- 7 to 63 +/- 19 mmol/min (P < 0.05), systemic oxygen consumption from 10.2 +/- 2.0 to 11.5 +/- 3.3 mmol/min (NS). HBF increased from 2.2 +/- 0.7 to 2.7 +/- 1.0 l/ min (P < 0.05), splanchnic oxygen delivery from 14.4 +/- 5.3 to 18.5 +/- 7.2 mmol/min (P < 0.01), and splanchnic oxygen consumption decreased from 3.9 +/- 1.1 to 2.9 +/- 0.6 mmol/min (P < 0.05). No significant changes in lower extremity flow and oxygenation variables were found. The use of dopamine in patients with ALF to increase MAP was associated with increases in systemic and splanchnic oxygen delivery. A concomitant decrease in splanchnic oxygen consumption was observed.