Calf muscle stimulation with the Veinoplus device results in a significant increase in lower limb inflow without generating limb ischemia or pain in patients with peripheral artery disease

A Multicenter, Investigator-Blinded, Randomized Controlled Trial to Assess the Efficacy of Calf Neuromuscular Electrical Stimulation Program on Walking Performance in Peripheral Artery Disease: The ELECTRO-PAD Study Protocol

This paper describes a currently on-going multicenter, randomized controlled trial designed to assess the efficacy of calf neuromuscular electrical stimulation (NMES) on changes in maximal walking distance in people with lower extremity peripheral artery disease (PAD), compared with a non-intervention control-group. This study (NCT03795103) encompasses five participating centers in France. PAD participants with a predominant claudication at the calf level and a maximal treadmill walking distance ≤300 m are randomized into one of the two groups: NMES group or Control group. The NMES program consists of a 12-week program of electrical stimulations at the calf-muscle level. The primary outcome of the study is the change in maximal treadmill walking distance at 12 weeks. Main secondary outcomes include changes in the pain-free treadmill walking distance; 6 min total walking distance; global positioning system (GPS)-measured outdoor walking capacity; daily physical activity level by accelerometry; self-reported walking impairment; self-reported quality of life; ankle-brachial index; and skin microvascular function, both at the forearm and calf levels. Recruitment started in September 2019 and data collection is expected to end in November 2022.

Challenges in recruitment and adherence to a randomized clinical trial in Brazil on the effects of transcutaneous nervous electrical stimulation on individuals with peripheral arterial disease: A feasibility study

OBJECTIVE

Describe the feasibility, barriers during the recruitment and intervention period, recruitment rate (success and efficiency), and the level of participation and adherence in the randomized clinical trial to verify the effects of transcutaneous electrical nerve stimulation (TENS) for the symptoms of intermittent claudication (IC) and its repercussions on functional capacity, cardiorespiratory fitness and cardiovascular autonomic function in individuals with sta II Fontaine classification, residing in Brazil.

DESIGN

Prospective, double-blind, randomized clinical trial.

SETTING

Level secondary.

PARTICIPANTS

A total of 63 participants were screened, of which 12.6% were included. Eight individuals with peripheral arterial disease (PAD) and IC underwent a protocol that lasted 8 weeks.

INTERVENTIONS

The experimental group received 45 minutes TENS 10 Hz, followed by 30 minutes of aerobic exercise, and the control group received a placebo TENS also followed by 30 minutes of exercise. Incremental walking test, gait impairment questionnaire, treadmill test, heart rate variability, and 4-second test were applied, considering adherence, success, and efficiency.

RESULTS

The most efficient recruitment sources were as follows: 1) referral by physician and 2) referral by a physiotherapist. Out of 63 participants, 8 (12.6%) were included in the clinical trial. Participants were excluded due to the following reasons: not meeting the criteria (41 participants (65%)), locomotion (6 participants (9.5%)), transportation (5 participants (7.9%)), work release (1 participant (1.6%)), and interest (2 participants (3.2%)). The overall participation was 99 participants (51.6%) in a total of 192 sessions offered.

CONCLUSION

It was not possible to succeed in recruitment and adherence rates. The results of this clinical trial reinforce that PAD is neglected, and strategies including a multidisciplinary approach with the effective participation of nursing, physiotherapy, medicine, and nutrition professionals, are necessary to optimize care for individuals with PAD need to be strengthened. Brazilian Registry of Clinical Trials (RBR-8RTZFN).

A systematic review of lower extremity electrical stimulation for treatment of walking impairment in peripheral artery disease

Lower extremity peripheral artery disease (PAD) induces an ischemic pain in the lower limbs and leads to walking impairment. Electrical stimulation has been used in patients with PAD, but no systematic review has been proposed to address the efficacy of the technique as a treatment for walking impairment in PAD. A systematic search was performed to identify trials focused on electrical stimulation for the treatment of walking impairment in patients with PAD in the Cochrane Central Register, PubMed, Embase, and the Web of Science. Studies were included where the primary outcomes were pain-free walking distance and/or maximal walking distance. When appropriate, eligible studies were independently assessed for quality using the Cochrane Collaboration's tool for assessing risk of bias. Five studies eligible for inclusion were identified, of which only two were randomized controlled studies. Trial heterogeneity prevented the use of the GRADE system and the implementation of a meta-analysis. Three types of electrical stimulation have been used: neuromuscular electrical stimulation (NMES, n = 3), transcutaneous electrical stimulation (n = 1), and functional electrical stimulation (n = 1). The two available randomized controlled studies reported a significant improvement in maximal walking distance (+40 m/+34% and +39 m/+35%, respectively) following a program of NMES. Owing to the low number of eligible studies, small sample size, and the risk of bias, no clear clinical indication can be drawn regarding the efficacy of electrical stimulation for the management of impaired walking function in patients with PAD. Future high-quality studies are required to define objectively the effect of electrical stimulation on walking capacity.

Effect of footplate neuromuscular electrical stimulation on functional and quality-of-life parameters in patients with peripheral artery disease: pilot, and subsequent randomized clinical trial

BACKGROUND

Supervised exercise programmes for intermittent claudication have poor access and limited compliance. Neuromuscular electrical stimulation (NMES) may be an effective alternative. A proof-of-concept study and RCT were conducted.

METHODS

In study 1, eligible patients underwent baseline assessment; treadmill testing for initial (ICD) and maximum (MCD) claudication distance; EuroQoL Five Dimensions five-level instrument (EQ-5D-5L™) and Intermittent Claudication Questionnaire (ICQ) assessment; and measurement of ultrasound haemodynamics of the superficial femoral artery. After familiarization with the NMES device, participants underwent a 30-min session of stimulation with concomitant recording of haemodynamic measures at 15 min, and after device cessation. Measurements were repeated after 6 weeks of daily use of NMES. In study 2, consecutive patients underwent baseline assessment before online randomization to a supervised exercise programme only, or adjunctive NMES treatment for 6 weeks, followed by repeat measurements.

RESULTS

Study 1 (20 patients) showed a significant improvement in MCD (46 per cent; P < 0·001) and ICD (71 per cent; P < 0·001). The RCT (42 patients) showed a significant adjunctive benefit of NMES in ICD (46 per cent; P = 0·014). Improvements were seen in the ICQ (9 points; P = 0·009) and EQ-5D-5L™ (P = 0·007) in study 1, and there was a significant adjunctive benefit of NMES on the ICQ score in patients who did supervised exercise (11·2 points; P = 0·031). Blood volume flow and time-adjusted mean velocity increased significantly with the device on (P < 0·050). Overall, NMES compliance exceeded 95 per cent.

CONCLUSION

Footplate NMES significantly improved walking distance in patients with intermittent claudication when used independently and also as an adjunct to supervised exercise. Registration number: trial 1, NCT02436200; trial 2, NCT02429310 (http://www.clinicaltrials.gov).

Effects of Intermittent Calf Muscle Electrical Stimulation on Walking Capacity in Claudicants Living with Type 2 Diabetes

BACKGROUND

First-line therapy for diabetic patients presenting with intermittent claudication includes supervised exercise programs to improve walking distance. However, exercise comes with a variety of barriers and may be contraindicated in certain conditions. The aim of this study was to evaluate whether calf muscle electrostimulation improves claudication distance.

METHODS

A prospective, one-group, pretest-posttest study design was used on 40 participants living with type 2 diabetes mellitus, peripheral artery disease (ankle brachial pressure index, <0.90), and calf muscle claudication. Calf muscle electrostimulation of varying frequencies (1-250 Hz) was prescribed on both limbs for 1-hour daily sessions for 12 consecutive weeks. The absolute claudication distance (ACD) was measured at baseline and after the intervention.

RESULTS

The recruited cohort (30 men and ten women; mean age, 71 years; mean ankle brachial pressure index, 0.70) registered a mean ± SD baseline ACD of 333.71 ± 208 m. After a mean ± SD of 91.68 ± 6.23 days of electrical stimulation, a significant mean ± SD increase of 137 ± 136 m in the ACD (P = .001, Wilcoxon signed rank test) was registered. Improvement was found to be sex independent, but age was negatively correlated with proportion of improvement (r = -0.361; P = .011, Pearson correlation test).

CONCLUSIONS

Electrical stimulation of varying frequencies on ischemic calf muscles significantly increased the maximal walking capacity in claudicants with type 2 diabetes. This therapeutic approach should be considered in patients with impaired exercise tolerance or as an adjunct treatment modality.

The effects of a calf pump device on second half performance of a simulated soccer match in competitive youth players

During soccer matches, performance decrements have been reported that relate to both physical abilities and technical skills. To investigate the effects of low-frequency electrical stimulation LFES (VeinoplusSport®, Ad Rem Technology, France) administered during half-time recovery on performance alterations during the second half. Twenty-two highly trained young players undertook a soccer-match simulation (SAFT⁹⁰). During half-time, they were randomly assigned to LFES group or Placebo group. Each half was split into 3 bouts of 12 minutes. Following each bout, maximal strike speed (MSS), sprint test (ST), maximal sprint accelerations (MA) and metabolic power (MP) were determined in both groups. Arterial (AF) and venous flows (VF) were measured at rest and at the end of half-time. LEFS group exhibited beneficial effects on performance compared to the Placebo group with a likely effect for MSS, ST, MA, and a possible effect for MP. AF and VF increased statistically more in LEFS group compared to Placebo group. The use of specific calf-pump LFES during half-time of a youth simulated soccer match attenuated the decrease in performance during the second half compared to Placebo group. This effect is most marked at the beginning of the second half with regards to explosive parameters.

The Effectiveness of Calf Muscle Electrostimulation on Vascular Perfusion and Walking Capacity in Patients Living With Type 2 Diabetes Mellitus and Peripheral Artery Disease

The aim of the study was to explore calf muscle electrostimulation on arterial inflow and walking capacity in claudicants with peripheral artery disease and diabetes mellitus. A prospective, 1-group, pretest-posttest study design was used on 40 high-risk participants (n = 40) who exhibited bilateral limb ischemia (ankle brachial pressure index [ABPI] <0.90), diabetes mellitus, and calf muscle claudication. A program of calf muscle electrical stimulation with varying frequency (1-250 Hz) was prescribed for 1 hour per day for 12 weeks. Spectral waveforms analysis, ABPI, absolute claudication distance (ACD), and thermographic temperature patterns across 4 specified regions of interest (hallux, medial forefoot, lateral forefoot, heel) at rest and after exercise, were recorded at baseline and following intervention to evaluate for therapeutic outcomes. A significant improvement in ACD and ABPI was registered following the intervention ( P = .000 and P = .001, respectively). Resting foot temperatures increased significantly ( P = .000) while the postexercise temperature drops were halved across all regions at follow-up, with hallux ( P = .005) and lateral forefoot ( P = .038) reaching statistical significance. Spectral Doppler waveforms were comparable ( P = .304) between both serial assessments. Electrical stimulation of varying frequency for 1 hour per day for 12 consecutive weeks registered statistically significant improvement in outcome measures that assess arterial inflow and walking capacity in claudicants with diabetes mellitus. These results favor the use of electrostimulation as a therapeutic measure in this high-risk population.

The LargPAD Trial: Phase IIA evaluation of l-arginine infusion in patients with peripheral arterial disease

OBJECTIVE

Endothelial function is improved by l-arginine (l-arg) supplementation in preclinical and clinical studies of mildly diseased vasculature; however, endothelial function and responsiveness to l-arg in severely diseased arteries is not known. Our objective was to evaluate the acute effects of catheter-directed l-arg delivery in patients with chronic lower extremity ischemia secondary to peripheral arterial disease.

METHODS

The study enrolled 22 patients (45% male) with peripheral arterial disease (mean age, 62 years) requiring lower extremity angiography. Endothelium-dependent relaxation of patent but atherosclerotic superficial femoral arteries was measured using a combination of intravascular ultrasound (IVUS) imaging and a Doppler FloWire (Volcano Corporation, Rancho Cordova, Calif) during the infusion of incremental acetylcholine (10^-6 to 10^-4 molar concentration) doses. Patients received 50 mg (n = 3), 100 mg (n = 10), or 500 mg (n = 9) l-arg intra-arterially, followed by repeat endothelium-dependent relaxation measurement (limb volumetric flow). IVUS-derived virtual histology of the culprit vessel was also obtained. Endothelium-independent relaxation was measured using a nitroglycerin infusion. Levels of nitrogen oxides and arginine metabolites were measured by chemiluminescence and mass spectrometry, respectively.

RESULTS

Patients tolerated limb l-arg infusion well. Serum arginine and ornithine levels increased by 43.6% ± 13.0% and 23.2% ± 10.3%, respectively (P < .005), and serum nitrogen oxides increased by 85% (P < .0001) after l-arg infusion. Average vessel area increased by 6.8% ± 1.3% with l-arg infusion (acetylcholine 10^-4; P < .0001). Limb volumetric flow increased in all patients and was greater with l-arg supplementation by 130.9 ± 17.6, 136.9 ± 18.6, and 172.1 ± 24.8 mL/min, respectively, for each cohort. Maximal effects were seen with l-arg at 100 mg (32.8%). Arterial smooth muscle responsiveness to nitroglycerin was intact in all vessels (endothelium-independent relaxation, 137% ± 28% volume flow increase). IVUS-derived virtual histology indicated plaque volume was 14 ± 1.3 mm³/cm, and plaque stratification revealed a predominantly fibrous morphology (46.4%; necrotic core, 28.4%; calcium, 17.4%; fibrolipid, 6.6%). Plaque morphology did not correlate with l-arg responsiveness.

CONCLUSIONS

Despite extensive atherosclerosis, endothelial function in diseased lower extremity human arteries can be enhanced by l-arg infusion secondary to increased nitric oxide bioactivity. Further studies of l-arg as a therapeutic modality in patients with endothelial dysfunction (ie, acute limb ischemia) are warranted.

The comparative hemodynamic efficacy of lower limb muscles using transcutaneous electrical stimulation

BACKGROUND

Circulation in the limbs can be augmented using transcutaneous electrical stimulation devices. The optimum muscle stimulation sites for enhancement of vascular hemodynamic parameters have not been identified.

METHODS

Seven suitable anatomic sites were identified within the right leg. Twelve healthy participants were recruited (mean age, 23.1 ± 3 years; body mass index, 23.1 ± 3 kg/m(2)). Muscles were stimulated by transcutaneous bipolar electrodes at a current twice their motor threshold, at 1 Hz, for 5 minutes. Hemodynamic ultrasound measurements were taken from the right femoral vein. Laser Doppler measurements from the feet of the stimulated and nonstimulated sides were obtained. Baseline measurements were compared with readings after 5 minutes of stimulation, with device active. Discomfort experienced for stimulation of each muscle was rated out of 100.

RESULTS

Hemodynamic changes displayed large intersubject variation, with no muscle statistically superior to the others. All muscles increased peak velocity; contraction of medial gastrocnemius increased time-averaged maximum velocity and volume flow. All muscles increased foot fluximetry (P < .05). Discomfort correlated weakly with current applied. Tibialis anterior and vastus lateralis were most tenable.

CONCLUSIONS

Transcutaneous stimulation increases hemodynamic parameters significantly, locally and systemically. No optimum stimulation site has been identified, and it is limited by comfort and variability in the subject's response. Gastrocnemius, tibialis anterior, and vastus lateralis all provoke large changes in hemodynamic parameters, but clinical efficacy in disease prevention and management has not been explored.

Non-Invasive Management of Peripheral Arterial Disease

BACKGROUND

Peripheral arterial disease (PAD) is common and symptoms can be debilitating and lethal. Risk management, exercise, radiological and surgical intervention are all valuable therapies, but morbidity and mortality rates from this disease are increasing. Circulatory enhancement can be achieved using simple medical electronic devices, with claims of minimal adverse side effects. The evidence for these is variable, prompting a review of the available literature.

METHODS

Embase and Medline were interrogated for full text articles in humans and written in English. Any external medical devices used in the management of peripheral arterial disease were included if they had objective outcome data.

RESULTS

Thirty-one papers met inclusion criteria, but protocols were heterogenous. The medical devices reported were intermittent pneumatic compression (IPC), electronic nerve (NMES) or muscle stimulators (EMS), and galvanic electrical dressings. In patients with intermittent claudication, IPC devices increase popliteal artery velocity (49-70 %) and flow (49-84 %). Gastrocnemius EMS increased superficial femoral artery flow by 140 %. Over 4.5-6 months IPC increased intermittent claudication distance (ICD) (97-150 %) and absolute walking distance (AWD) (84-112 %), with an associated increase in quality of life. NMES of the calf increased ICD and AWD by 82 % and 61-150 % at 4 weeks, and 26 % and 34 % at 8 weeks. In patients with critical limb ischaemia IPC reduced rest pain in 40-100 % and was associated with ulcer healing rates of 26 %. IPC had an early limb salvage rate of 58-83 % at 1-3 months, and 58-94 % at 1.5-3.5 years. No studies have reported the use of EMS or NMES in the management of CLI.

CONCLUSION

There is evidence to support the use of IPC in the management of claudication and CLI. There is a building body of literature to support the use of electrical stimulators in PAD, but this is low level to date. Devices may be of special benefit to those with limited exercise capacity, and in non-reconstructable critical limb ischaemia. Galvanic stimulation is not recommended.

The Use of Transcutaneous Electrical Stimulation of the Calf in Patients Undergoing Infrainguinal Bypass Surgery

BACKGROUND

Infrainguinal bypass surgery is frequently associated with postoperative reperfusion edema of the limb. The etiology is thought to be multifactorial, and there is as yet no standardized treatment protocol for this problem. The primary aim of this study was to assess whether the use of intermittent electrical stimulation of the calf muscles after infrainguinal bypass surgery was effective in reducing the incidence of edema, and the secondary aims to determine the effect of calf muscle stimulation on arterial and venous flow in the operated leg.

METHODS

Forty patients due to undergo infrainguinal bypass surgery for critical lower-limb ischemia (Fontaine grading III-IV or Rutherford grading II-III) were recruited prospectively and randomly divided into the control group, who received the current standard of care, and study group, who received electrical calf muscle stimulation for a 1 hour session twice daily for the first postoperative week. Preoperatively and postoperatively, the leg was measured at 3 predetermined points and a duplex ultrasound scan performed.

RESULTS

The groups were well matched for all parameters. At 1 week, the below knee and calf girth were less in the study group (P = 0.025 and P = 0.043, respectively). Venous flow volumes at rest and on stimulation were higher in the study group (P = 0.010 and P = 0.029, respectively). At 6 weeks, the below knee girth and amount of pitting edema were less in the study group (P = 0.011 and P = 0.014, respectively).

CONCLUSIONS

We conclude that transcutaneous electrical stimulation of the calf decreased lower-limb swelling at 1 and 6 weeks, and increased the venous flow volume at rest and on stimulation at 1 week in patients undergoing infrainguinal bypass surgery for critical ischemia regardless of patient factors or the type of bypass surgery performed or graft used.

The role of kinesitherapy and electrotherapeutic procedures in non-operative management of patients with intermittent claudications

PURPOSE

To examine the effects of physical therapy (kinesitherapy and electrotherapeutic procedures) on the course of peripheral arterial occlusive disease by monitoring the changes in values of claudication distance and ankle-brachial indexes.

METHODS

Prospective randomized study included 47 patients with peripheral arterial occlusive disease manifested by intermittent claudications associated with ankle-brachial indexes values ranging from 0.5 to 0.9. Patients from the first group (25 pts) were treated with medicamentous therapy, walking exercises beyond the pain threshold, dynamic low-burden kinesi exercises and electrotherapeutic ageneses (interference therapy, diadynamic therapy, and electromagnetic field), while the second group of patients (22 pts) was treated with "conventional" non-operative treatment - medicamentous therapy and walking exercises. The values of newly established absolute claudication distance and ankle-brachial indexes were measured.

FINDINGS

Significant increase of absolute claudication distance in both groups of patients was registered, independently of therapeutic protocol applied (p < 0.001), as well as the increase in the claudication distance interval in the physical therapy group. There was no significant increase in ankle-brachial indexes values in both groups of patients.

CONCLUSION

Methods of physical therapy presented valuable supplement in non-operative treatment of peripheral arterial occlusive disease patients, improving their functional ability and thus postponing surgical treatment. However, further investigations including larger number of patients are needed.

Influence of isolated or simultaneous application of electromyostimulation and vibration on leg blood flow

PURPOSE

The aim of this study was to analyze the acute effects of isolated or simultaneously applied whole-body vibration (WBV) and electromyostimulation (ES) on the popliteal arterial blood velocity and skin temperature (ST) of the calf.

METHODS

Thirteen healthy males were assessed in five different sessions. After a familiarization session, four interventions were applied in random order; WBV, ES, simultaneous WBV and ES (WBV+ES), and 30 s of WBV followed by 30 s of ES (WBV30/ES30). Each intervention consisted of 10 sets × 1 min ON + 1 min OFF. The subject was standing on the vibration platform (squat position, 30° knee flexion, 26 Hz, 5 mm peak-to-peak), and ES was applied on the gastrocnemius of both the legs (8 Hz, 400 µs).

RESULTS

The WBV+ES intervention was the only one that maintained the mean blood velocity (MBV) elevated above baseline during the 10 sets, from set-1 (134.6 % p < 0.01) to set-10 (112.6 % p < 0.05). The combined interventions were the only ones that maintained the peak blood velocity (PBV) elevated above baseline during all the sets, from set-1 (113.5 % p < 0.001) to set-10 (88.8 % p < 0.01) and from set-1 (58.4 % p < 0.01) to set-10 (49.1 % p < 0.05) for WBV+ES and WBV30/ES30, respectively.

CONCLUSION

The simultaneous application of WBV and ES produced a general greater increase in MBV and PBV than the application of each method alone or consecutive. This novel methodological proposal could be interesting in different fields such as sports or the rehabilitation process of different pathologies, to achieve an enhanced peripheral blood flow.

Evaluation of a textile-based near infrared spectroscopy system in calf muscle oxygenation measurements

We recently introduced a novel textile-based NIRS sensor (TexNIRS). Here, we evaluate TexNIRS in ten subjects (16 legs, age 28.5 ± 2.32 years, adipose tissue thickness (ATT) 4.17 ± 1.71 mm). Three venous occlusions at 50 mmHg were performed on their calf muscle. After 3 min of occlusion, oxy/deoxy hemoglobin concentration ([O₂Hb], [HHb]) changes were 3.71 ± 1.89/1.79 ± 1.08 μM; venous oxygen saturation (SvO₂) was 75 ± 9.7 %, oxygen consumption (VO₂) was 0.02 ± 0.01 mL/100 g/min, hemoglobin flow (HF) was 0.93 ± 0.48 μmol/100 mL/min, and blood flow (BF) was 2.01 ± 1.04 mL/100 mL/min. Our results are in good agreement with the literature, but the TexNIRS enables a much higher level of comfort.

Positive effect of specific low-frequency electrical stimulation during short-term recovery on subsequent high-intensity exercise

The objective of this study was to test how low-frequency electrical stimulation (LFES; Veinoplus Sport (AdRem Technology, Paris, France)) of the calf muscles affects recovery indices compared with 2 other commonly used recovery methods (active, ACT; passive, PAS). The tests used assessed predominantly anaerobic performance after short-term (15 min) recovery, and the kinetics of blood markers. Fourteen highly trained female handball players completed 2 Yo-Yo Intermittent Recovery tests (level 2; YYIR2) separated by a 15-min recovery period. During recovery, 1 of 3 recovery methods (ACT, LFES or PAS) was randomly selected. Performance (i.e., distance run) was measured at the end of each YYIR2 test. Blood lactate, pH, bicarbonate concentrations, heart rate, respiratory gas exchange and tissue saturation index for the lateral gastrocnemius were recorded. LFES showed a very likely beneficial effect on performance during the second YYIR2 relative to PAS and a possible beneficial effect relative to ACT (distance Pre vs. Post; LFES: -1.8%; ACT: -7.6%; PAS: -15.9%). Compared with PAS recovery, LFES and ACT recovery clearly showed a faster return to baseline for blood lactate, pH and bicarbonate concentrations during the recovery period. LFES of the calf muscles and, to a lesser extent, ACT recovery appear to effectively improve short-term recovery between 2 bouts of exhausting exercises. These methods could be of benefit if applied during half-time, for sports involving successive rounds, or where only a limited recovery period is available.