Augmentation of venous, arterial and microvascular blood supply in the leg by isometric neuromuscular stimulation via the peroneal nerve

Blood flow effects of percutaneous peripheral nerve stimulation. A blinded, randomized clinical trial

BACKGROUND

The vasculature function is mainly regulated by the autonomic nervous system. Importantly, the sensory-motor nervous system also innervates peripheral vessels and has the capacity to modulate vascular tone. Here we investigated the effects of electrical stimulation of a mixed nerve trunk on blood flow in deep arteries and muscle perfusion. Our hypothesis is that stimulation of a mixed nerve can modify blood flow.

METHODS

Twenty-nine healthy participants were included into a randomized-crossover and blinded clinical trial. Each subject received a placebo and two percutaneous peripheral nerve stimulation (pPNS) protocols on the median nerve: Pain Threshold continuous Low Frequency (PT-cLF) and Sensory Threshold burst High Frequency (ST-bHF). Blood flow was then assessed bilaterally using Power Doppler Ultrasonography at the main arteries of the arm, and blood perfusion at the forearm muscles. Afterwards, blood flow was quantified using a semi-automatized software, freely shared here.

RESULTS

Placebo, consisting in needle insertion, produced an immediate and generalized reduction on peak systolic velocity in all arteries. Although nerve stimulation produced mainly no effects, some significant differences were found: both protocols increased the relative perfusion area of the forearm muscles, the ST-bHF protocol prevented the reduction in peak systolic velocity and TAMEAN of the radial artery produced by the control protocol and PT-cLF produced a TAMEAN reduction of the ulnar artery.

CONCLUSIONS

Therefore, the arterial blood flow in the arm is mainly impervious to the electrical stimulation of the median nerve, composed by autonomic and sensory-motor axons, although it produces mild modifications in the forearm muscles perfusion.

Wearable Neuromuscular Electrical Stimulation on Quadriceps Muscle Can Increase Venous Flow

Neuromuscular electrical stimulation (NMES) of the quadriceps (Q) may increase venous blood flow to reduce the risk of venous thromboembolism. This study assessed whether Q-NMES pants could increase peak venous velocity (PVV) in the femoral vein using Doppler ultrasound and minimize discomfort. On 15 healthy subjects, Q-NMES using textile electrodes integrated in pants was applied with increasing intensity (mA) until the first visible muscle contraction [measurement level (ML)-I] and with an additional increase of six NMES levels (ML II). Discomfort using a numeric rating scale (NRS, 0-10) and PVV were used to assess different NMES parameters: frequency (1, 36, 66 Hz), ramp-up/-down time (RUD) (0, 1 s), plateau time (1.5, 4, and 6 s), and on:off duty cycle (1:1, 1:2, 1:3, 1:4). Q-NMES pants significantly increased PVV from baseline with 93% at ML I and 173% at ML II. Frequencies 36 Hz and 66 Hz and no RUD resulted in significantly higher PVV at both MLs compared to 1 Hz and 1 s RUD, respectively. Plateau time, and duty cycle did not significantly change PVV. Discomfort was only significantly higher with increasing intensity and frequency. Q-NMES pants produces intensity-dependent 2-3-fold increases of venous blood flow with minimal discomfort. The superior NMES parameters were a frequency of 36 Hz, 0 s RUD, and intensity at ML II. Textile-based NMES wearables are promising for non-episodic venous thromboembolism prevention.

Effects on hemodynamic enhancement and discomfort of a new textile electrode integrated in a sock during calf neuromuscular electrical stimulation

PURPOSE

To compare fixed transverse textile electrodes (TTE) knitted into a sock versus motor point placed standard gel electrodes (MPE) on peak venous velocity (PVV) and discomfort, during calf neuromuscular electrical stimulation (calf-NMES).

METHODS

Ten healthy participants received calf-NMES with increasing intensity until plantar flexion (measurement level I = ML I), and an additional mean 4 mA intensity (ML II), utilizing TTE and MPE. PVV was measured with Doppler ultrasound in the popliteal and femoral veins at baseline, ML I and II. Discomfort was assessed with a numerical rating scale (NRS, 0-10). Significance was set to p < 0.05.

RESULTS

TTE and MPE both induced significant increases in PVV from baseline to ML I and significantly higher increases to ML II, in both the popliteal and femoral veins (all p < 0.001). The popliteal increases of PVV from baseline to both ML I and II were significantly higher with TTE versus MPE (p < 0.05). The femoral increases of PVV from baseline to both ML I and II were not significantly different between TTE and MPE. TTE versus MPE resulted at ML I in higher mA and NRS (p < 0.001), and at ML II in higher mA (p = 0.005) while NRS was not significantly different.

CONCLUSION

TTE integrated in a sock produces intensity-dependent increases of popliteal and femoral hemodynamics comparable to MPE, but results in more discomfort at plantar flexion due to higher current required. TTE exhibits in the popliteal vein higher increases of PVV compared to MPE.

TRIAL REGISTRATION

Trial_ID: ISRCTN49260430. Date: 11/01/2022. Retrospectively registered.

Efficacy of a novel wearable transcutaneous tibial nerve stimulation device on bladder reflex compared to implantable tibial nerve stimulation in cats

OBJECTIVE

To determine the efficacy of novel wearable transcutaneous tibial nerve stimulation (TTNS) device on bladder reflex in cats compared to implantable tibial nerve stimulation (ITNS).

MATERIALS AND METHODS

Two self-adhesive electrodes of the TTNS device were placed at the left leg, and ITNS was applied to stimulate the tibial nerve of the right leg, respectively. The intensity threshold (T) was defined as inducing observable toe movement. Multiple cystometrograms (CMGs) with normal saline (NS) infusion were performed to determine the inhibitory effects of TTNS and ITNS on the micturition reflex.

RESULTS

TTNS at 4 times T (4 T), 6 times T (6 T), and the maximum output current intensity 24 mA significantly increased the bladder capacity (BC) compared to the control level (8.70 ± 2.46 ml) (all p < 0.05); however, there was no statistical significance among the three intensities. At the same time, ITNS at 2 times T (2 T), 4 T, 6 T, and the current intension 24 mA could significantly increase the BC compared to the control level (all p < 0.05). Likewise, no significant difference was observed among the four intensities (p > 0.05). The T values of TTNS were higher than those of ITNS (p = 0.02). The inhibitory effects of TTNS and ITNS revealed no significant difference at their respective 2 T, 4 T, 6 T, and 24 mA. Neither TTNS nor ITNS changed the contraction duration and amplitude (all p > 0.05).

CONCLUSIONS

TTNS was effective in increasing BC. The non-invasive neuromodulation technique could achieve a similar effect as ITNS.

Phlebological insole: Can it help in the lymphoedema treatment? A scoping review

BACKGROUND

The treatment of lymphoedema requires a multi-professional and interdisciplinary approach. Despite being prescribed in the management of lymphatic disorders, the effectiveness of the phlebological insoles is still under investigation.

AIM

This scoping review aims to identify and analyse evidence regarding the efficacy of phlebological insoles as a conservative intervention for lower limb lymphoedema.

METHOD

The following databases were searched up to November 2022: PubMed, Cochrane Library, CINAHL Complete, PEDro and Scopus. Preventive and conservative interventions were considered. Studies considering people with lower limb oedema, of any age and type of oedema, were eligible for inclusion. No restrictions in terms of language, year of publication, study design and type of publication were applied. Additional studies were sought through grey literature.

RESULTS

From 117 initial records, 3 studies met the inclusion criteria. Two quasi-experimental studies and one randomised cross-over study were included. The results of the examined studies confirmed the positive effects of insoles usage and foot and ankle mobility on the venous return.

CONCLUSION

This scoping review provided an overview of the topic. The studies analysed in this scoping review have shown that insoles seem to be beneficial in reducing the lower limb oedema in healthy individuals. However, there are still no comprehensive trials confirming this evidence on people with lymphoedema. The small number of identified articles, the selection of participants not affected by lymphoedema, the use of heterogeneous devices in terms of modifications and materials highlight the need of further investigations. Future trails should include people affected by lymphoedema, address the choice of materials in manufacturing the insoles and take in consideration the patients' adherence to the device and concordance to the treatment.

The impact of a new intervention for venous leg ulcers: A within-patient controlled trial

A major obstacle to the development of new treatments for venous leg ulcers is the difficulty in generating evidence for their effectiveness. Randomised controlled trials using complete healing as the endpoint are seldom powered to be successful, owing to the heterogeneity of cohorts. A novel approach to the evaluation of treatments is presented, using a self-controlled trial model and two metrics of short-term healing rate as alternate endpoints: rate of wound margin advance, and percentage area reduction over 4 weeks. Two different treatment regimens are compared: multi-layer compression alone, versus multi-layer compression combined with activation of the venous leg pump by neuromuscular stimulation. With 60 patients, adding neuromuscular stimulation to multilayer compression resulted in a significant two-fold increase in the rate of wound healing over a 4-week period, both in terms of wound margin advance and in terms of percentage area reduction. The use of these short-term intermediate endpoint metrics together with a self-controlled study design offers potential for distinguishing between the relative efficacies of interventions more rapidly, with greater sensitivity, and with fewer subjects than a conventional RCT cohort model.

Effectiveness of Neuromuscular Electrical Stimulation for Enhanced Recovery After Total Hip Replacement Surgery: A Randomized Controlled Trial

Background

The aim of this study was to investigate the feasibility of using a novel neuromuscular electrical stimulation (NMES) device for enhanced recovery after total hip replacement surgery.

Methods

Sixty patients undergoing total hip replacement for osteoarthritis of the hip were randomized and divided into 2 groups: 1 group received postoperative treatment with the NMES device, and the other group did not receive NMES. The primary outcome measures were postoperative pain, lower limb swelling, and length of stay (LOS) postsurgery. Secondary outcomes included wound drainage at 24 hours and acceptability by the intervention of the device.

Results

Data from 60 participants were analyzed (NMES (n = 30), control group (n = 30)). Patients in the NMES group demonstrated a general trend of beneficial postoperative pain, calf swelling, and average length of stay from postoperative to discharge. However, wound drainage largely remained static for both groups. The overall comfort rate of the device was 93.3%.

Conclusions

The results of this study suggest that the geko^TM NMES device is partly useful for enhanced recovery after total hip replacement surgery. In addition, the device should be considered tolerable and safe. A larger study is required with this device in the future to determine its effectiveness on compelling data.

Role of Neuromuscular Electrical Stimulation in Increasing Femoral Venous Blood Flow After Total Hip Prosthesis

Objective: This study aimed to investigate the role of neuromuscular electrical stimulation (NMES) in increasing femoral venous blood flow after total hip prosthesis and to evaluate its potential effects on preventing postoperative deep vein thrombosis (DVT).

Materials and methods: A total of 64 patients who underwent total hip prosthesis were randomly separated into two groups. The NMES group (n=32) received low-molecular-weight heparin+NMES. And the non-NMES group (n=32) received a low-molecular-weight heparin+compression bandage.

Results: There was no difference between the groups in terms of the presence of preoperative and postoperative leg edema. The calf diameter was significantly lower in the NMES group than in the non-NMES group in both the preoperative (p=0.003) and postoperative (p=0.008) period. Although the femoral vein peak velocity (VPV) was similar between the groups in the preoperative period, it was significantly higher in the NMES group than in the non-NMES group postoperatively (p=0.001). The femoral VPV after total hip prosthesis increased more in the NMES group (43.2%) compared with the non-NMES group (16.3%). In the non-NMES group, the D-dimer value in the preoperative period was lower than on postoperative days one and five (p<0.05). There was no significant difference between the D-dimer values on postoperative days one and five. In the NMES group, a statistically significant difference was determined between the preoperative and postoperative test results (F(2.93)=20.86, p=0.001). The preoperative D-dimer values were compared to the postoperative values on the first and fifth day, and according to the post hoc test results, the D-dimer values were significantly lower on the fifth postoperative day than on the first postoperative day, and the preoperative value was significantly lower than the fifth postoperative day value (p<0.05). 

Conclusion: Although the two groups were similar in terms of leg edema, there was a significant increase in femoral VPV in the NMES group. This could indicate a potential effect of NMES in preventing postoperative DVT and needs to be confirmed with further studies.

Effects on venous flow of transcutaneous electrical stimulation, neuromuscular stimulation, and sham stimulation on soleus muscle: A randomized crossover study in healthy subjects

BACKGROUND

Activation of venous flow has been shown with different types of electrical stimulation. The aim of this study is to compare the hemodynamic effects of transcutaneous electrical nerve stimulation (TENS), neuromuscular electrical stimulation (NMES), and sham stimulation on healthy young people.

METHODS

This randomized crossover study was conducted during June 2018 in the Faculty of Physical Therapy of A Coruña (Spain). Twenty-four university students (50% male) received in a randomized order 5 Hz-TENS, NMES, and sham stimulation on soleus muscle. Flow volume (FV) and peak velocity (PV) from popliteal vein were recorded via Doppler ultrasound, and relative changes from baseline were determined. Discomfort among the 3 stimulations was also compared.

RESULTS

The differences among the 3 stimulations were assessed using the ANOVA for repeated measured, the Friedman test and the Kendall tau test, according to the type of measurement to be compared. FV (mL/min) and PV (cm/s) increased significantly after NMES (percentual increase 37.2 ± 62.0%, P = .002; 264.4 ± 152.2%, P < .001, respectively) and TENS (226.2 ± 190.3%, P < .001; 202.7 ± 144.6%, P < .001, respectively). These percentual changes from basal level in hemodynamics were statistically different to those after placebo, which was ineffective enhancing hemodynamics. The improvements in FV were statistically higher with TENS than with NMES (P < .001), but there was no statistical difference in PV (P = .531). Despite NMES was applied at a significantly lower amplitude than TENS (P < .001), NMES protocol was the worst tolerated, though the differences in discomfort were not statistically significant.

CONCLUSION

Both active electrical protocols but not sham stimulation increased hemodynamics in healthy people. TENS obtained higher flow volume increase from baseline than NMES, considered globally at not only in its on-time.

Feasibility of a Transcutaneous Tibial Nerve Stimulation Device Use in Overactive Bladder Patients: A Pilot Study From a Single Tertiary Care Center

Purpose

To evaluate the preliminary efficacy, safety, and acceptability of a transcutaneous tibial nerve stimulation (TTNS) device in overactive bladder (OAB) patients.

Methods

Twenty OAB patients who failed with conservative treatments were recruited consecutively. All patients received 60 min of daily unilateral stimulation for 4 weeks using a smart wearable transcutaneous tibial nerve stimulation device and the stimulations were at 20 Hz frequency, 200 μs pulse width. OAB symptoms were observed at baseline and week 4, using a 3-days voiding diary, the overactive bladder symptom score (OABSS), the perception of bladder condition (PPBC), and the American Urological Association Symptom Index Quality of Life Score (AUA-SI-QoL). Urodynamic characteristics were measured to determine the pilot efficacy of the device during the treatment comparing the baseline parameters to the post-treatment parameters.

Results

Among the patients, 15 cases were OAB-dry and five cases were OAB-wet. All patients were evaluated at the end of the study and no significant side effects were found during the treatment. The daily micturition frequency and the number of incontinence episodes per day were reduced from 15.10 ± 1.61 to 12.00 ± 4.56, and 3.20 ± 0.80 to 0.47 ± 0.38, respectively. The mean voiding volume was increased from 130.10 ± 53.07 to 157.30 ± 66.95 mL. The OABSS, AUA-SI-QoL, and PPBC were reduced from 9.35 ± 1.39 to 5.9 ± 2.36, 5.70 ± 0.47 to 3.85 ± 1.04, and 5.70 ± 0.47 to 4.35 ± 0.86, respectively. The first sensation of bladder filling (1st SBF), maximal bladder capacity (MBC), and mean compliance were increased from 87.50 (60.00–167.50) to 150.00 (104.00–211.30) mL, 175.00 (120.30–354.00) to 255.00 (151.50–491.50) mL, and 36.67 (12.44–39.69) to 40.00 (20.00–52.50) mL/cmH2O, respectively. The maximum detrusor pressure (Pdet. max) was reduced from 14.50 (5.00–35.25) to 11.00 (6.00–20.00) cmH2O.

Conclusion

The preliminary results demonstrated that the TTNS device was safe, effective, and acceptable to use in OAB patients, but the results need to be substantiated by conducting more randomized controlled studies further.

Clinical Study of Neuromuscular Electrical Stimulation in the Prevention of Deep Venous Thrombosis of Lower Extremities after Anterior Cruciate Ligament Reconstruction

This paper is written to observe the clinical effects of "neuromuscular electrical stimulation in the prevention of deep venous thrombosis of lower extremities after anterior cruciate ligament reconstruction" in our department. Data from March 2018 to March 2021 was selected including 187 males and 91 females. They were randomly divided into experimental groups and control groups. The experimental group adopted DVT general prevention + basic physical prevention + NMES and the control group adopted DVT general prevention + basic physical prevention. The VAS score, the content of blood D-dimer, the circumference of the affected knee, and results of DVT color ultrasound screening were studied in each group on the first day before operation and the fourth day after the operation. Results obtained showed that there were no significant differences in the baseline characteristics of the two groups of patients, such as gender composition, age, and so on (P > 0.05). The VAS scores, blood D-dimer content, and knee circumference of each group on the day before and on the fourth day after surgery were observed. Diameter and DVT color Doppler ultrasound screening results were superior to the control group in the test group and the difference was statistically significant (P < 0.05). It was concluded that NMES can effectively reduce the pain, knee swelling, and incidence of DVT in patients after ACL reconstruction. It is a simple and effective intervention therapy to prevent the occurrence of DVT.

Pilot Trial of Neuromuscular Stimulation in Human Subjects with Chronic Venous Disease

Introduction

Neuromuscular stimulation (NMES) has been shown to improve peripheral blood flow in healthy people. We investigated the effect of bilateral leg NMES on the symptoms of chronic venous disease.

Methods

Forty subjects were recruited from four groups: healthy, superficial insufficiency, deep insufficiency, and deep obstruction. Haemodynamic venous measurements were taken from the right femoral vein with ultrasound, laser Doppler fluximetry from the left hand and foot. Devices were then worn for 4–6 hours per day, for 6 weeks. Haemodynamic measurements were repeated at week 6. Quality of life questionnaires were taken at week 0, 6 and 8.

Results

The mean age was 48.7, BMI 28.6kg/m2, and maximum calf circumference 39.0 cm. Twenty-four subjects were men. NMES increased femoral vein peak velocity, TAMV and volume flow by 55%, 20%, 36% at 20 minutes (all p<0.05), which was enhanced at week 6 (PV and TAMV p<0.05). Mean increases in arm and leg fluximetry were 71% and 194% (both p<0.01). Leg swelling was reduced by mean 252.7 mL (13%, p<0.05) overall; 338.9 mL (16%, p<0.05) in venous disease. For those with venous pathology, scores for disease specific and generic quality of life questionnaires improved. Those with C4-6 disease benefitted the most, with improvements in VDS score of 1, AVVQ of 6, and SF-12 of 10.

Conclusion

NMES improves venous haemodynamic parameters in chronic venous disease, which is enhanced by regular use. NMES reduces leg oedema, improves blood supply to the skin of the foot, and may positively affect quality of life.

Clinical Trials

This trial was registered with www.clinicaltrials.org.uk (NCT02137499).

Sitting for Too Long, Moving Too Little: Regular Muscle Contractions Can Reduce Muscle Stiffness During Prolonged Periods of Chair-Sitting

In modern Western societies, sedentary behavior has become a growing health concern. There is increasing evidence that prolonged sitting periods can be associated with musculoskeletal disorders. While it is generally recognized that back muscle activity is low during chair-sitting, little is known about the consequences of minor to no muscle activity on muscle stiffness. Muscle stiffness may play an important role in musculoskeletal health. This study investigated the effects of regular muscle contractions on muscle stiffness in a controlled experiment in which participants sat for 4.5 h. Neuromuscular electrical stimulation in the lumbar region of the back was applied to trigger regular muscle contractions. Using stiffness measurements and continuous motion capturing, we found that prolonged sitting periods without regular muscle contractions significantly increased back muscle stiffness. Moreover, we were able to show that regular muscle contractions can prevent those effects. Our results highlight the importance of consistent muscle activity throughout the day and may help explain why prolonged periods of chair-sitting increase the susceptibility to common pathological conditions such as low back pain.

Microcirculatory changes in venous leg ulcers using intermittent electrostimulation of common peroneal nerve

OBJECTIVE

Activation of the venous muscle pumps of the leg by intermittent transdermal neuromuscular stimulation of the common peroneal nerve has been previously shown to augment venous and arterial flow in patients with leg ulcers. This study aims to establish if microcirculation in the wound bed and periwound area are augmented by the activation of a neuromuscular electrostimulation device (NMES) (Geko, Firstkind Ltd., UK).

METHOD

In this self-controlled, observational study, laser speckle contrast imaging was used to map and quantify microcirculatory flow in the wound bed and periwound area of patients with venous leg ulcers (VLU). Values of flow and pulsatility in these locations were compared with the NMES device, both active and inactive.

RESULTS

A total of 16 patients took part in the study. Microvascular flux increased by 27% (p=0.014) in the wound bed, and by 34% (p=0.004) in the periwound area, when the NMES device was activated. Pulsatility increased by 170% (p<0.001) in the wound bed and 173% (p<0.001) in the periwound area when the device was activated.

CONCLUSION

Intermittent electrostimulation of the common peroneal nerve substantially increased both microcirculatory flux and pulsatility in the wound bed and in the periwound area of the VLUs of patients in this study. This provides a plausible mechanistic explanation for its reported efficacy in healing VLUs.

Use of electrical muscle stimulation body massager (EMS-BMs) improves deep venous blood flow

We investigated whether using electrical muscle stimulation body massagers (EMS-BMs) for the passive contraction of the lower extremity muscles reduces venous stasis in the deep veins of the lower extremities. In this randomized crossover design study of 20 healthy volunteers between November 2018 and February 2019, we measured both the popliteal and femoral vein peak velocities (PV, cm/s) and blood flow volumes (BFV,mL/min), using pulsed-wave Doppler ultrasound at rest (baseline), and at 2 and 10 min after starting EMS-BM use. Two EMS types: types A (two small pads) and B (one large pad) devices respectively, were examined. The PVs of the femoral (A: 23±7, B: 25±8) and popliteal (A: 26±12, B: 27±12) veins and BFV of types A (107±46) and B (141±88) of the femoral vein were significantly increased compared to the baseline (PV of femoral vein: 19±9, PV of popliteal vein: 14±5, BFV of popliteal vein: 81±46) (P<0.01). No significant differences occurred between the devices in the PV or BFV at either 2 or 10 min. Regardless of the type of stimulation or the shape of the pad, contraction of the lower limb muscles by EMS-BM effectively reduces venous stasis in the lower limb.

Local and Contralateral Effects after the Application of Neuromuscular Electrostimulation in Lower Limbs

Neuromuscular electrostimulation (NMES) has been used mainly as a method to promote muscle strength, but its effects on improving blood flow are less well known. The aim of this study is to deepen the knowledge about the local and contralateral effects of the application of symmetric biphasic square currents on skin temperature (Tsk). An experimental pilot study was developed with a single study group consisting of 45 healthy subjects. Thermographic evaluations were recorded following the application of NMES to the anterior region of the thigh. The results showed an increase in the maximal Tsk of 0.67% in the anterior region of the thigh where the NMES was applied (p < 0.001) and an increase of 0.54% (p < 0.01) due to cross-education effects, which was higher when the NMES was applied on the dominant side (0.79%; p < 0.01). The duration of the effect was 20 min in the dominant leg and 10 min in the nondominant one. The application of a symmetrical biphasic current (8 Hz and 400 μs) creates an increase in the maximal Tsk at the local level. A temperature cross-education effect is produced, which is greater when the NMES is applied on the dominant side. This could be a useful noninvasive measurement tool in NMES treatments.

Neuromuscular stimulation of the common peroneal nerve increases arterial and venous velocity in patients with venous leg ulcers

Activation of the venous muscle pumps by neuromuscular stimulation of the common peroneal nerve has been previously shown to increase venous and arterial flow in the legs of healthy subjects. The aim of this study is to determine whether a similar effect is observed in patients with chronic venous leg ulcers. 1 Hz intermittent electrostimulation of the common peroneal nerve was applied to 14 patients with ulcers between 1 and 10 cm in diameter, eliciting a small, painless, regular, muscular twitch of the leg. Flow was measured using Duplex ultrasound in the popliteal vein and the popliteal artery. Peak arterial velocity increased from 57 to 78 cm/s (P = .001) in sitting position, and from 79 to 98 cm/s in recumbent position (P = .001). Peak venous velocity increased from 10 to 33 cm/s (P = .001) sitting, and from 14 to 47 cm/s (P = .001) recumbent. Significant increases were observed in both venous and arterial blood flow in the lower limb. This suggestsed that activation of the venous muscle pump and improvement of arterial flow assisted oxygen delivery at the wound site. Moreover this may be a worthwhile intervention to assist in the healing of venous leg ulcers, and may provide a mechanistic explanation for the increased healing rates previously reported with neuromuscular stimulation of the common peroneal nerve.

Design of a Device for Lower Limb Prophylaxis and Exercise

The problem of immobility of legs leading to a potentially life threatening condition including deep venous thrombosis (DVT) is well known. The reduced mobility of leg affects a large number of patients in a wide range of clinical scenarios spanning from swelling of the legs to pulmonary embolism. In normal human beings, an elegant system of venous return, both active and passive is responsible for prevention of deep venous thrombosis. The paper proposes a prophylaxis and exercise device that mimics the natural principles of venous return to promote the blood flow. The device is based on electromechanical actuation, and simultaneous alternating compression mechanism, that is compact and, suitably form fitted in design and additionally requires no specialised training for the usage. The device was tested on a healthy volunteer on two different days and findings support the efficacy of the prophylaxis and exercise device in significantly improving the blood flow rate in the lower limb. The prototype device is considered as a major step towards designing a clinically validated lower limb device.

A randomised controlled trial of neuromuscular stimulation in non-operative venous disease improves clinical and symptomatic status

BACKGROUND

This randomised controlled trial investigates the dosing effect of neuromuscular electrical stimulation (NMES) in patients with chronic venous disease (CVD).

METHODS

Seventy-six patients with CEAP C3-C5 were randomised to Group A (no NMES), B (30 minutes of NMES daily) or C (60 minutes of NMES daily). Primary outcome was percentage change in Femoral Vein Time Averaged Mean Velocity (TAMV) at 6 weeks. Clinical severity scores, disease-specific and generic quality of life (QoL) were assessed.

RESULTS

Seventy-six patients were recruited - mean age 60.8 (SD14.4) and 47:29 male. Six patients lost to follow-up. Percentage change in TAMV (p<0.001) was significantly increased in Groups B and C. Aberdeen Varicose Veins Questionnaire Score (-6.9, p=0.029) and Venous Clinical Severity Score (-4, p-0.003) improved in Group C, and worsened in Group A (+1, p=0.025).

CONCLUSIONS

Daily NMES usage increases flow parameters, with twice daily usage improving QoL and clinical severity at 6 weeks in CVD patients.

Is Low-Frequency Electrical Stimulation a Tool for Recovery after a Water Rescue? A Cross-Over Study with Lifeguards

This study aimed to evaluate the degree to which transcutaneous electrical stimulation (ES) enhanced recovery following a simulated water rescue. Twenty-six lifeguards participated in this study. The rescue consisted of swimming 100 m with fins and rescue-tube: 50 m swim approach and 50 m tow-in a simulated victim. Blood lactate clearance, rated perceived effort (RPE), and muscle contractile properties were evaluated at baseline, after the water rescue, and after ES or passive-recovery control condition (PR) protocol. Tensiomiography, RPE, and blood lactate basal levels indicated equivalence between both groups. There was no change in tensiomiography from pre to post-recovery and no difference between recovery protocols. Overall-RPE, legs-RPE and arms-RPE after ES (mean ± SD; 2.7 ± 1.53, 2.65 ± 1.66, and 2.30 ± 1.84, respectively) were moderately lower than after PR (3.57 ± 2.4, 3.71 ± 2.43, and 3.29 ± 1.79, respectively) (p = 0.016, p = 0.010, p = 0.028, respectively). There was a significantly lower blood lactate level after recovery in ES than in PR (mean ± SD; 4.77 ± 1.86 mmol·L^-1 vs. 6.27 ± 3.69 mmol·L^-1; p = 0.045). Low-frequency ES immediately after a water rescue is an effective recovery strategy to clear out blood lactate concentration.

Microcirculatory Flux and Pulsatility in Arterial Leg Ulcers is Increased by Intermittent Neuromuscular Electrostimulation of the Common Peroneal Nerve

BACKGROUND

Neuromuscular electrical stimulator (NMES) devices increase blood flow to the lower limb by a process of intermittent muscular contraction initiated by a transdermal stimulus to the common peroneal nerve. However, its effects on localized microvascular blood supply to lower limb wounds are unknown. This study is a single-center open label study measuring the effect of neuromuscular stimulation of the common peroneal nerve on the microvascular blood flow within the wound bed of arterial leg ulcers.

METHODS

Eights patients with ischemic lower limb wounds had an NMES (geko™) applied to the common peroneal nerve. Baseline and intervention analysis of blood flow to the wound bed and edge was performed using Laser Speckle Contrast Imaging. Mean flow (flux) and pulse amplitude (pulsatility) were measured.

RESULTS

Stimulation of the common peroneal nerve with the NMES resulted in a significantly increased flux and pulsatility in both the wound bed and the wound edge in all 8 patients.

CONCLUSIONS

Neuromuscular electrical stimulation immediately increases microcirculatory blood flow to the wound bed and edge in patients with ischemic lower limb wounds. These data may provide mechanistic insight into the clinical efficacy of NMES in healing wounds. www.clinicaltrials.gov NCT03186560.

Daily use of a muscle pump activator device reduces duration of hospitalization and improves early graft outcomes post-kidney transplantation: A randomized controlled trial

INTRODUCTION

Kidney and simultaneous pancreas-kidney (SPK) transplant recipients can have prolonged postoperative hospitalization due to edema. Thrombo-embolic-deterrent (TED) stockings with intermittent pneumatic compression devices (TED+IPC) have been used to improve venous return during the perioperative period. The objective of this trial was to evaluate the effects of TED+IPC vs. muscle pump activator (MPA) devices on factors that could reduce postoperative complications and duration of hospitalization.

METHODS

In this single-center, prospective, randomized, controlled trial, 221 kidney and SPK transplant recipients were randomized to either wearing TED+IPC or MPA for six days postoperatively. Groups were compared with respect to postoperative urine output, lower limb edema, weight, days in hospital, mobility, serum creatinine, delayed graft function, need for dialysis, and lower extremity blood flow.

RESULTS

Patients in the MPA group had significantly higher urine output and less increase in mid-calf leg circumference and weight gain compared to the TED+IPC group (p=0.003, p=0.001, and p=0.003, respectively). The MPA group also experienced shorter hospitalization (p=0.038), higher femoral vein velocity (p=0.001), and took more steps (p=0.009). Incidence of delayed graft function (p=0.72) and number of dialysis runs (p=0.39) was not different between study groups. Subgroup analysis of primary endpoints in donation after cardiac death recipients and SPK recipients did not yield any significance between the study arms.

CONCLUSIONS

Postoperative use of the MPA device increases urine output, decreases leg edema, minimizes weight gain, and decreases duration of hospitalization after kidney transplantation. A larger and longer-term trial is needed to evaluate the impact on graft function.

Tibial nerve stimulation in the treatment of overactive bladder syndrome: technical features of latest applications

PURPOSE OF REVIEW

Overactive bladder syndrome (OAB) is a chronic condition, which can be treated by tibial nerve stimulation. The present review will focus on the technical aspects, advantages, drawbacks, and limitations of the latest available applications of posterior tibial nerve stimulation.

RECENT FINDINGS

We describe the technical aspects of recent developed implants and techniques of tibial nerve stimulation in a transcutaneous, percutaneous, and minimal invasive way. All different treatment options have advantages and disadvantages based on type of surgery, energy transfer, impedance, treatment setting options, risk of migration, and patient usability, which are described in this review. Only devices with data that are publicly available were included.

SUMMARY

New technologies are on their way in the field of tibial nerve stimulation for the treatment of OAB. Technical aspects are important to demonstrate safety and efficacy and user friendliness in order to obtain high acceptance of the various devices.

Impact of Active Recovery and Whole-Body Electromyostimulation on Blood-Flow and Blood Lactate Removal in Healthy People

This study aimed to determine whether an active recovery with added whole-body electromyostimulation (WB-EMS) can increase blood flow and lead to blood lactate removal after intense exercise. Thirty-five healthy individuals (23.1 ± 4.6 years) were randomly assigned to: (a) an experimental group using active recovery together with the WB-EMS (n = 18) or (b) a control group using the same active recovery protocol with the suit with no-stimulation (CON, n = 17). Participants performed a maximal graded exercise test followed by an active recovery protocol (walking at 40% of their maximum aerobic velocity). During the recovery, participants in WB-EMS and CON received continuous stimulation at 7 Hz or no stimulation, respectively. Heart rate, blood lactate concentrations, pain/discomfort, and hemodynamic measurements were recorded before and after the test, and repeated immediately after and at min 30 and 60. The between-group analysis showed a substantially greater Peak blood velocity (-0.27 [-0.68; 0.14]) in WB-EMS compared to CON. The pain/discomfort levels were also lower in WB-EMS compared with CON (0.66 [-0.12; 1.45]). Non-significant differences in participants' blood lactate were observed in WB-EMS compared with CON both immediately; at 30and 60 min. Our findings suggest that increased local blood flow induced by WB-EMS may have contributed to greater lactate removal from active muscles and blood lactate clearance. WB-EMS may be an effective means of increasing muscle blood flow after a maximal graded exercise test and could result in improved recovery.

Effects of graduated compression stockings, local vibration and their combination on popliteal venous blood velocity

Objectives

The purpose of this pilot study was to examine and compare the effects of graduated compression stockings, local vibration, and combined graduated compression stockings and local vibration on popliteal venous blood velocity.

Method

Twenty-four healthy subjects received four 15 min interventions (control, graduated compression stockings alone, local vibration alone, and combined graduated compression stockings and local vibration), while resting inactive in the prone position. Popliteal vein blood velocity was investigated before (PRE) and at the end (POST) of each intervention using Doppler ultrasound.

Results

At POST, peak velocity was reported to be 26.3 ± 53.5% ( p <  0.05) greater for local vibration than control (CONT). Peak velocity was 46.2 ± 54.6% ( p <  0.001) and 21.1 ± 37.6% ( p <  0.01) higher for graduated compression stockings than CONT and local vibration, respectively. Graduated compression stockings + local vibration presented 64.1 ± 58.0% ( p <  0.001), 38.4 ± 52.4% ( p <  0.001) and 15.0 ± 31.6% ( p <  0.05) greater values than CONT, local vibration and graduated compression stockings, respectively.

Conclusions

This study demonstrated an increase in popliteal venous blood velocity after graduated compression stockings and local vibration application. Their combination provided the greatest effects.

The effect of wearing insoles with a toe-grip bar on occupational leg swelling and lower limb muscle activity: A randomized cross-over study

OBJECTIVE

Sitting or standing for hours decreases the blood flow in the legs and results in increased pressure on the veins, leading to the development of chronic venous disease. This study aimed to investigate the effects of insoles with a toe-grip bar on occupational leg swelling and lower limb muscle activity.

METHODS

This randomized cross-over study enrolled 12 healthy men who work in a sitting or standing position. They were randomly divided into groups A (wore shoes with insoles with a toe-grip bar for 8 hours each) and B (wore shoes with regular insoles for 8 hours each). After 1 week, groups A and B wore shoes with regular insoles and shoes with insoles with a toe-grip bar, respectively, for 8 hours each. Lower leg volume was measured before and after each intervention, and lower limb muscle activity was measured at the start of each intervention.

RESULTS

Occupational leg swelling was significantly smaller in men wearing insoles with a toe-grip bar (P < .05). Moreover, the integrated electromyogram value of the tibialis anterior muscle and medial and lateral gastrocnemius muscles during the stance phase of walking, and tibialis anterior muscle during the swing phase of walking was significantly greater in men wearing insoles with a toe-grip bar (all P < .05).

CONCLUSION

Insoles with a toe-grip bar contribute to increased lower limb muscle activity, attenuating occupational leg swelling.

Use of a Muscle Pump Activator Leads to Improved Lower Limb Edema, Lower Limb Blood Flow, and Urine Output Compared With Standard TED Stockings and Compression Devices Following Kidney Transplant: A Randomized Controlled Trial

OBJECTIVE

The aim of this study was to evaluate the effects of using thromboembolic deterrent (TED) stockings and intermittent pneumatic compression (IPC) vs a muscle pump activator (MPA) device on limb edema and patient satisfaction after transplant.

METHODS

In this single-center randomized controlled trial, 118 patients were randomly assigned to wear TED + IPC (n = 64) or the MPA device (n = 54) from postoperative days 1 to 6. We measured patients' weight and lower leg and thigh circumferences daily. Ultrasonography of the allograft and lower limbs was carried out on postoperative days 1 and 5 to assess resistive index in the transplanted kidney and flow in the femoral vein. We monitored urine output and serum creatinine level.

RESULTS

We observed a significant increase in calf and thigh circumference from baseline in the TED + IPC group but not in the MPA group (2.3 [SD, 1] cm vs 0.25 [SD, 0.8] cm, respectively, P < .002). Ultrasonography showed higher femoral vein velocities in the MPA group than the TED + IPC group (0.5 [SD, 0.2] cm, P < .001). The mean total urine output in 6 days was higher in the MPA group than the TED + IPC group (P = .05), which corresponded to large change in TED + IPC weight of 6.2 kg vs 2.1 kg in the MPA group (P = .04). Patients were more satisfied with the use of the MPA device than TED + IPC. No major complications were encountered in either group.

CONCLUSIONS

This is the first study to show that the use of an MPA device in the immediate postoperative period following kidney transplant leads to decreased lower limb edema and increased total urine output. Patients were more satisfied with the use of the MPA device than TED + IPC.

The effects of knee joint angle on neuromuscular activity during electrostimulation in healthy older adults

Introduction

Electrostimulation devices stimulate the common peroneal nerve, producing a calf muscle-pump action to promote venous circulation. Whether knee joint angle influences calf neuromuscular activity remains unclear. Our aim was to determine the effects of knee joint angle on lower limb neuromuscular activity during electrostimulation.

Methods

Fifteen healthy, older adults underwent 60 min of electrostimulation, with the knee joint at three different angles (0°, 45° or 90° flexion; random order; 20 min each). Outcome variables included electromyography of the peroneus longus, tibialis anterior and gastrocnemius medialis and lateralis and discomfort.

Results

Knee angle did not influence tibialis anterior and peroneus longus neuromuscular activity during electrostimulation. Neuromuscular activity was greater in the gastrocnemius medialis (p = 0.002) and lateralis (p = 0.002) at 90°, than 0° knee angle. Electrostimulation intensity was positively related to neuromuscular activity for each muscle, with a knee angle effect for the gastrocnemius medialis (p = 0.05).

Conclusion

Results suggest that during electrostimulation, knee joint angle influenced gastrocnemii neuromuscular activity; increased gastrocnemius medialis activity across all intensities (at 90°), when compared to 0° and 45° flexion; and did not influence peroneus longus and tibialis anterior activity. Greater electrostimulation-evoked gastrocnemii activity has implications for producing a more forceful calf muscle-pump action, potentially further improving venous flow.

Electrical stimulation devices for the prevention of venous thromboembolism: Preliminary studies of physiological efficacy and user satisfaction

Introduction

Electrical stimulation could provide an alternative method for preventing venous thromboembolism in stroke patients. The purpose of this preliminary study was to explore the effects of electrical stimulation and intermittent pneumatic compression on enhancing lower limb venous return in healthy and chronic stroke patients and also to evaluate patient and nurse satisfaction.

Methods

We investigated the effectiveness of two electrical stimulation devices: Geko (Firstkind Ltd, High Wycombe, UK) and Orthopaedic Microstim 2V2 (Odstock Medical Ltd, Salisbury, UK); and one intermittent pneumatic compression device: Huntleigh Flowstron Universal (Huntleigh Healthcare Ltd, Cardiff, UK). We recruited 12 healthy and 5 chronic stroke participants. The devices were fitted sequentially, and Doppler ultrasound measurements were taken. Eight patients and nurses were also recruited for a separate usability evaluation.

Results

The electrical stimulation devices emulated the blood flow characteristics of intermittent pneumatic compression in both healthy and stroke participants provided that the intensity of electrical stimulation was sufficient. Patients and nurses also felt that the electrical stimulation devices were acceptable.

Conclusions

Electrical stimulation may offer benefit as an alternative method for venous thromboembolism prevention in stroke patients. The apparent benefit is sufficient to warrant further investigation in a full powered randomised controlled trial.

The impact of a muscle pump activator on incisional wound healing compared to standard stockings and compression devices in kidney and kidney-pancreas transplant recipients: A randomized controlled trial

INTRODUCTION

We aimed to evaluate the impact of thrombo-embolic-deterrent + intermittent pneumatic compression (TED + IPC) vs. muscle pump activator (MPA) on incisional wound healing in kidney and simultaneous pancreas- kidney (SPK) transplant recipients.

METHODS

We conducted a single-centre, randomized controlled trial in which 104 patients (kidney n=94; SPK n=10) were randomly assigned to wear TED + IPC (n= 52) or MPA (n=52) for the first six days following surgery. Patient demographics, postoperative outcomes, and incisional wound images were taken using a HIPAA-compliant application on postoperative days (POD) 3, 5, and 30, and assessed using the validated Southampton Wound Care Score.

RESULTS

There were no demographic differences between the groups. The MPA group had a significant improvement in wound healing on POD 3 (p=0.04) that persisted until POD 5 (p=0.0003). At POD 30, both groups were similar in wound healing outcomes (p=0.51). Bayesian inferential analysis revealed that the use of TED + IPC following transplantation had inferior outcomes compared to the use of MPA with sequential moderate evidence. The rate of complex wound infections was significantly greater in the TED + IPC group compared to the MPA group (29% vs. 12%, respectively; p=0.03). Patients were more satisfied with the use of a MPA device than TED + IPC. No major complications were encountered in either group.

CONCLUSIONS

The use of a MPA device in the immediate postoperative period leads to a significant improvement in immediate and early wound healing, and decreased number of complex wound infections following kidney and SPK transplantation compared to standard TED + IPC therapy. Patients were more satisfied with the use of a MPA device than TED + IPC.

Feasibility of using a novel non-invasive ambulatory tibial nerve stimulation device for the home-based treatment of overactive bladder symptoms

Background

To evaluate safety, acceptability and pilot efficacy of transcutaneous low-frequency tibial nerve stimulation (TNS) using a novel device as home-based neuromodulation.

Methods

In this single-centre pilot study, 48 patients with overactive bladder (OAB) (24 with neurogenic and 24 with idiopathic OAB) were randomized to use a self-applicating ambulatory skin-adhering device stimulating transcutaneously the tibial nerve at 1 Hz for 30 minutes, either once daily or once weekly, for 12 weeks. Changes in OAB symptoms and QoL were measured at baseline, weeks 4, 8, and 12 using validated scoring instruments (ICIQ-OAB and ICIQ-LUTSqol), 3-day bladder diary and a Global Response Assessment (GRA) at week 12.

Results

Thirty-four patients completed the study (idiopathic n=15, neurogenic n=19). No significant adverse effects were noted. Patients found the device acceptable. Eighteen patients (53%) reported a moderate or marked improvement in symptoms from the GRA. Between baseline and week-12, ICIQ-OAB part A sub-scores improved from mean (SD) 9.3 (2.5) to 7.5 (3.1), and from 9.1 (1.9) to 5.9 (1.7) in the daily and the weekly arms, respectively. ICIQ-LUTSqol part A sub-scores improved from mean (SD) 51 (12.8) to 44.2 (13.1) and 44.9 (9.0) to 35.9 (8.8) in the daily and the weekly arms, respectively. Bladder diary mean 24-hour frequency episodes improved from 11.5 to 8.8 at week 12 for both arms.

Conclusions

This novel ambulatory transcutaneous TNS (TTNS) device is safe and acceptable for use in patients reporting OAB symptoms as a form of home-based neuromodulation. A larger study however is required to confirm clinical efficacy.

Using a muscle pump activator device to stimulate healing for non-healing lower leg wounds in long-term care residents

Chronic non‐healing wounds are a burden in the Long‐Term Care (LTC) sector, increasing costs, morbidity, and mortality and causing pain and suffering. The objective of this LTC Innovation pilot was to test the value of a promising new neuromuscular stimulation device in elevating the experience and satisfaction of the residents, engaging and empowering the nursing staff, and improving healing and/or reducing costs. Small, wireless, and worn at the knee, this muscle pump activator is self‐contained, wearable, and battery‐powered to increase lower‐leg blood circulation (up to 60% of that achieved by walking). It has no wires, weighs just 10 g, and is easy to use. Nurses in four LTC homes identified residents with non‐healing lower leg wounds. Consent was obtained, and on‐site training was delivered. Eleven residents were recruited. Only seven met the inclusion criteria for venous/mixed or diabetic foot ulcers. Of the seven who met the criteria and were adherent with best practices and the muscle pump activator, four healed 100%, and one healed 90%. Two patients with other aetiologies, who were also adherent, healed. All adherent residents had an average weekly decrease in wound size of 9.75% and were extremely happy with the results. Three residents who were non‐adherent had a 9.25% increase in wound size per week. One patient with diabetic foot ulcers developed skin changes at the end of life and passed away. Nursing staff and cognisant residents can easily adjust the pulse of muscle pump activator, and application and removal are simple. Most residents feel engaged with the therapy “because they feel it working”. The LTC corporation feels that it is a great adjunctive solution for many types of lower‐leg wounds (venous, mixed, diabetic, pressure) in addition to best practices in the LTC and Retirement home sectors.

Effects of transcutaneous electrical nerve stimulation via peroneal nerve or soleus muscle on venous flow: A randomized cross-over study in healthy subjects

BACKGROUND

Transcutaneous electrical nerve stimulation (TENS) is used to prevent venous stasis and thromboembolism. However, best electrostimulation parameters have yet to be established. The aim of the study was to compare the hemodynamic effects and the participants' relative discomfort of 3 TENS sequences at the maximum tolerated intensity stimulus.

METHODS

Twenty-four healthy university students (50% male) participated in a cross-over, randomized study. Each participant received 2 TENS sequences on peroneal nerve at 1 and 5 Hz, and the third one on soleus muscle at 5 Hz. Popliteal flow volume (FV) and peak velocity (PV) were measured using Doppler ultrasound and the relative change from basal values was recorded. Discomfort questionnaires -visual analogue scale (VAS) and verbal rating scale (VRS)- were also administered to compare sensations among the three applications.

RESULTS

All interventions produced significant hemodynamic responses compared to baseline. Both 5 Hz applications obtained higher FV increments than 1 Hz TENS (P < .001). The muscle application resulted in the lowest PV increment (P < .001). TENS at 5 Hz on nerve location was the worst tolerated, with higher values in VRS (P = .056) and VAS (P = .11), although not significant.

CONCLUSION

TENS at 5 Hz on soleus site may be the most appropriate protocol for enhancing venous return.

A feasibility randomised controlled trial to evaluate the effectiveness of a novel neuromuscular electro-stimulation device in preventing the formation of oedema following total hip replacement surgery

Aim

The aim of this feasibility study was to investigate the potential role of a novel neuromuscular electrical stimulation (NMES) device in preventing the formation of oedema following total hip replacement (THR).

Methods

Successive primary THR patients were recruited into a randomised controlled trial. Participants were randomised to wear either the NMES device or compression stockings continually from post-surgery until discharge.

The main outcome measure was presence of lower limb oedema, assessed by taking measurements of the circumference of the ankle, knee and thigh on the operated leg and non-operated leg, pre-operatively, post-operatively, at two days post-operatively and every day until discharge. Secondary objectives were to compare adverse events, the presence of asymptomatic and symptomatic deep vein thrombosis (DVT) and device tolerability between groups.

Results

Data from 40 participants were analysed (NMES (n = 20), compression stockings (n = 20)). The NMES group had significantly less oedema and the device was found to be tolerable and safe.

Conclusion

The results of this study suggest that the NMES is a safe and well tolerated alternative to compression stockings, which should be considered by clinicians seeking the additional benefit of reducing post-operative oedema. In addition the NMES device should be considered as part of a DVT prophylaxis.

Refractory venous leg ulcers: observational evaluation of innovative new technology

This observational case series reports the evaluation of a novel neuromuscular electrical stimulation device (geko™) that stimulates the common peroneal nerve at the fibular head as an adjunctive therapy in patients with non-healing venous leg ulcers. The aim was to evaluate and determine if the geko™ device was effective in this population and should be added to the medical supply formulary. Patients whose wounds had failed to heal within 24 weeks of standard therapy were identified in two community settings in Ontario. A total of 11 patients consented to the evaluation with a combined 107-year history of recalcitrant leg ulcers. Although the pre-geko™ healing rate was unknown, all ulcers were considered non-healing. With geko™, the average weekly percentage reduction in surface area for all patients was 4·5% and for the six adherent to geko™ and best practices 7·0%. By comparison, the average weekly percentage reduction for measurable wounds in the five non-adherent patients was 1·8%. Requirements for success appear to include an arterial status adequate for healing, effective and prompt management of wound infections and adherence to the treatment schedule. The geko™ device has been added to the medical supply formulary in one centre and is pending in the other.

Neuromuscular electrical stimulation for the prevention of venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is a serious but preventable cause of morbidity and mortality. Neuromuscular electrical stimulation systems (NMES) for the prevention of VTE may be beneficial for patients in whom pharmacological or standard mechanical prophylaxis methods are contraindicated or are regarded as unsafe or impractical. Although findings of experimental studies suggest that NMES reduce venous stasis, the clinical utility and effectiveness of NMES in VTE prevention remain controversial.

OBJECTIVES

To assess the effectiveness of neuromuscular electrical stimulation in the prevention of venous thromboembolism.

SEARCH METHODS

The Cochrane Vascular Group Information Specialist (CIS) searched the Specialised Register (22 March 2017) and the Cochrane Central Register of Controlled Studies (CENTRAL (2017, Issue 2)). The CIS also searched trial registries for details of ongoing and unpublished studies. The review authors searched the bibliographic lists of relevant articles and reviews to look further for potentially eligible trials.

SELECTION CRITERIA

We planned to include randomised controlled trials (RCTs) and quasi-randomised trials that compared any form of neuromuscular electrical stimulation as an intervention for VTE prophylaxis (alone or combined with pharmacological or other mechanical methods) versus no prophylaxis and other mechanical or pharmacological methods of VTE prophylaxis.

DATA COLLECTION AND ANALYSIS

At least two independent review authors were involved in study selection, data extraction, methodological quality assessment of included studies, and data analysis. We resolved disagreements by discussion between the two review authors. If no agreement could be reached, a third review author acted as an adjudicator. The main outcomes of the review were total deep vein thrombosis (DVT), symptomatic and asymptomatic DVT, pulmonary embolism (PE), total VTE and bleeding (major and minor). The quality of evidence was assessed using the GRADE approach and is indicated in italics.

MAIN RESULTS

We included in the review five randomised controlled trials and three quasi-randomised trials, enrolling a total of 904 participants. Among these, four studies included patients undergoing major surgical procedures; one study included patients undergoing surgery for hip fracture under spinal anaesthesia; one study included trauma patients with a contraindication for prophylactic heparin; one study included neurosurgical patients who were operated on under general anaesthesia; and one study included patients with non-functional spinal cord injuries. Overall, eight studies investigated 22 treatment arms. Four studies compared the NMES arm with a no prophylaxis arm, and five studies compared the NMES arm with alternative methods of prophylaxis arms. Alternative methods of prophylaxis included low-dose heparin (5000 IU subcutaneously) - two studies, Dextran 40 - one study, graduated compression stockings (GCS) and intermittent pneumatic compression devices (IPCD) - one study. One study compared combined NMES and low-dose heparin versus no prophylaxis or low-dose heparin alone.We found no clear difference in risks of total DVT (odds ratio (OR) 1.01, 95% confidence interval (CI) 0.60 to 1.70, P = 0.98; 6 studies, 415 participants; low-quality evidence), asymptomatic DVT (OR 1.61, 95% CI 0.40 to 6.43, P = 0.50; 1 study, 89 participants; low-quality evidence), symptomatic DVT (OR 0.40, 95% CI 0.02 to 10.07, P = 0.58; 1 study, 89 participants; low-quality evidence), PE (OR 1.31, 95% CI 0.38 to 4.48, P = 0.67; 2 studies, 126 participants;low-quality evidence), and total VTE (OR 0.92, 95% CI 0.34 to 2.52, P = 0.88; 1 study, 72 participants; low-quality evidence) between prophylaxis with NMES and alternative methods of prophylaxis. None of the studies in this comparison reported bleeding.Compared with no prophylaxis, NMES showed lower risks of total DVT (OR 0.40, 95% CI 0.23 to 0.70, P = 0.02; 4 studies, 576 participants; moderate-quality evidence) and total VTE (OR 0.23, 95% CI 0.09 to 0.59, P = 0.002; 1 study, 77 participants; low-quality evidence). Data show no clear differences in risk of asymptomatic DVT (OR 0.32, 95% CI 0.06 to 1.62, P = 0.17; 1 study, 200 participants; low-quality evidence), symptomatic DVT (OR 0.06, 95% CI 0.00 to 1.36, P = 0.08; 1 study, 160 participants;low-quality evidence), or PE (OR 0.36, 95% CI 0.12 to 1.07, P = 0.07; 1 study, 77 participants; low-quality evidence) between prophylaxis with NMES and no prophylaxis. None of the studies in this comparison reported bleeding.In comparison with low-dose heparin, NMES was associated with higher risk of total DVT (OR 2.78, 95% CI 1.19 to 6.48, P = 0.02; 2 studies, 194 participants; low-quality evidence), but data were inadequate for other comparisons (NMES vs Dextran 40, NMES vs GCS, or NMES vs IPCD) and for other clinical outcomes such as symptomatic or asymptomatic DVT, PE, total VTE, and bleeding in individual comparisons.Overall, we judged the quality of available evidence to be low owing to high or unclear risk of bias and imprecise effect estimates due to small numbers of studies and events.

AUTHORS' CONCLUSIONS

Low-quality evidence shows no clear difference in the risk of DVT between NMES and alternative methods of prophylaxis but suggest that NMES may be associated with lower risk of DVT compared with no prophylaxis (moderate-quality evidence) and higher risk of DVT compared with low-dose heparin (low-quality evidence). The best available evidence about the effectiveness of NMES in the prevention of VTE is not adequately robust to allow definitive conclusions. Adequately powered high-quality randomised controlled trials are required to provide adequately robust evidence.

Clinical and Functional Results of 119 Patients With Knee Dislocations

OBJECTIVES

To describe clinical results and functional outcomes of knee dislocations treated with a consistent strategy within our institution.

DESIGN

Retrospective case series.

SETTING

Level 1 trauma center.

PATIENTS

One hundred nineteen patients were treated at one institution between 2000 and 2014 for knee dislocation.

MAIN OUTCOME MEASUREMENTS

Knee range of motion, functional instability, and complications were recorded. Musculoskeletal Function Assessment (MFA) and Lysholm scores were obtained after minimum of 1 year.

RESULTS

Sixty-three early complications were noted in 36 patients (32%), with an overall amputation rate of 9.2% (8 early and 3 late amputations). Of the patients who retained their limb, 4.5% reported instability. Open knee dislocations were associated with amputation (26% vs. 1.3%, P < 0.001). Popliteal arterial injuries were associated with more amputation (31% vs. 3.2%, P = 0 < 0.001), infection (37% vs. 8%, P = 0.002), and deep venous thrombosis (32% vs. 8.8%, P = 0.014). Patients with wound infection were more likely to develop heterotopic ossification (36% vs. 9.4%, P = 0.017) and less knee motion (77.5 vs. 117 degrees P = 0.049). Knee motion improved over time for all patients with a mean arc of 86 degrees at 3 months, 109 degrees at 6 months, and 115 degrees at 12 months. An Injury Severity Score of ≥20 was associated with less knee motion (97 vs. 121 degrees P = 0.029). Mean Lysholm score was 86.7, and mean MFA score was 35.7 after mean follow-up of 90 months and 82 months, respectively.

CONCLUSIONS

Few patients (4.5%) experienced functional instability. However, early complications occurred frequently (32%) as expected, particularly in patients with open injuries and/or arterial injury. Limitations in knee motion were associated with high Injury Severity Score, infection, and heterotopic ossification. Mean knee scores were good, consistent with reasonable knee function, although MFA scores suggest a lower level of generalized function.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The effect of calf neuromuscular electrical stimulation and intermittent pneumatic compression on thigh microcirculation

OBJECTIVE

This study compares the effectiveness of a neuromuscular electrical stimulation (NMES) device and an intermittent pneumatic compression (IPC) device on enhancing microcirculatory blood flow in the thigh of healthy individuals, when stimulation is carried out peripherally at the calf.

MATERIALS AND METHODS

Blood microcirculation of ten healthy individuals was recorded using laser speckle contrast imaging (LSCI) technique. A region of interest (ROI) was marked on each participant thigh. The mean flux within the ROI was calculated at four states: rest, NMES device with visible muscle actuation (VMA), NMES device with no visible muscle actuation (NVMA) and IPC device.

RESULTS

Both NMES and IPC devices increased blood flow in the thigh when stimulation was carried out peripherally at the calf. The NMES device increased mean blood perfusion from baseline by 399.8% at the VMA state and 150.6% at the NVMA state, IPC device increased the mean blood perfusion by 117.3% from baseline.

CONCLUSION

The NMES device at VMA state increased microcirculation by more than a factor of 3 in contrast to the IPC device. Even at the NVMA state, the NMES device increased blood flow by 23% more than the IPC device. Given the association between increased microcirculation and reduced oedema, NMES may be a more effective modality than IPC at reducing oedema, therefore further research is needed to explore this.

Augmentation of arterial blood velocity with electrostimulation in patients with critical limb ischemia unsuitable for revascularization

Aim

This pilot study aimed to reveal whether combination of electrostimulation with iloprost treatment achieves better results compared to iloprost alone in patients with critical limb ischemia.

Material and methods

Patients were randomized into Group 1 ( n = 11, mean age: 65.3 ± 4.2 years, received iloprost infusion protocol alone) or Group 2 ( n = 11, mean age: 62.9 ± 6.7, received iloprost infusion plus standardized protocol of peroneal nerve electrostimulation). Electrostimulation was delivered with 1 Hz frequency, 27 mA current, and 200 ms pulse width. Peak blood flow velocities in the anterior and posterior tibialis arteries were measured with duplex ultrasound.

Results

There was a slight insignificant increase in blood velocity in anterior tibialis artery in Group 1 (from 17.6 ± 13.0 to 18.6 ± 13.1, p = 0.57), whereas the increase in Group 2 was marked (from 23.8 ± 18.3 to 32.2 ± 19.7, p = 0.01). Blood velocity in posterior tibialis artery also increased in both groups, but it was not of statistical significance. No significant difference was found between two groups in regard to final pulse oximetry oxygen saturation levels.

Conclusion

Electrostimulation of the peroneal nerve caused a substantial increase in anterior tibialis artery blood velocity when used as an adjunct to medical therapy in patients with critical limb ischemia.

Electrical muscle stimulation in thomboprophylaxis: review and a derived hypothesis about thrombogenesis-the 4th factor

INTRODUCTION

Electrical muscle stimulation (EMS) is an FDA-approved thromboprophylactic method. Thrombus pathogenesis is considered to depend on factors related to components of the vessel wall, the velocity of blood, and blood consistency-collectively known as, the Virchow's triad.

OBJECTIVE

The testimony supporting the thromboprophylactic effects of the EMS is reviewed. An emphasis is placed on the fact that, EMS has demonstrated, in certain circumstances, an efficacy rate that cannot be fully explained by the Virchow's triad; also that, in reviewing relevant evidence and the theorized pathophysiological mechanisms, several findings collectively point to a potentially missed point. Remarkably, venous thromboembolic disease (VTE) is extremely more common in the lower versus the upper extremities even when the blood velocities equalize; EMS had synergistic effects with intermittent compressive devices, despite their presumed identical mechanism of action; sleep is not thrombogenic; non-peroperative EMS is meaningful only if applied ≥5 times daily; neural insult increases VTEs more than the degree expected by the hypomobility-related blood stasis; etc. These phenomena infer the presence of a 4th thrombogenetic factor: neural supply to the veins provides direct antithrombic effects, by inducing periodic vessel diameter changes and/or by neuro-humoral, chemically acting factors. EMS may stimulate or substitute the 4th factor. This evidence-based hypothesis is analyzed.

CONCLUSION

A novel pathophysiologic mechanism of thrombogenesis is supported; and, based on this, the role of EMS in thromboprophylaxis is expanded. Exploration of this mechanism may provide new targets for intervention.

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.

A Review of the Evidence to Support Neuromuscular Electrical Stimulation in the Prevention and Management of Venous Disease

INTRODUCTION

The prevention and management of venous disease is a therapeutic challenge. Movement of blood through the venous system is augmented by the action of muscles on the deep veins, and can be achieved through the application of electrical current. The efficacy of currently available clinical devices for this purpose is unknown, and is investigated here.

METHODS

A literature search of the EMBASE and Medline databases was performed, and studies were included if they were full text articles, written in english, pertaining to venous disease and neuromuscular electrical stimulation (NMES).

RESULTS

NMES devices increase venous haemodynamic parameters such as peak velocity and volume flow. Studies report them to be non-inferior to intermittent pneumatic compression. They are effective in the prevention of venous thromboembolism, though inferior to low molecular weight heparin. NMES can reduce symptoms of chronic venous disease.

DISCUSSION

NMES is an important tool in the prevention and management of venous disease, and avoids the significant risks associated with heparin administration. Data explored here is heterogenous in device, protocol, and reported end-points, therefore should be interpreted with care. Long term effects of treatment with NMES have not been explored.

The Impact of Peripheral Nerve Stimulation on Coronary Blood Flow and Endothelial Function

PURPOSE

The geko™ device is a small transcutaneous nerve stimulator that is applied non-invasively to the skin over the common peroneal nerve to stimulate peripheral blood flow. The purpose of this study was to investigate the effect of peripheral nerve stimulation on coronary flow dynamics and systemic endothelial function.

METHODS

We enrolled 10 male patients, age 59 ± 11 years, with symptomatic obstructive coronary disease undergoing percutaneous coronary intervention (PCI). Coronary flow dynamics were assessed invasively using Doppler flow wire at baseline and with nerve stimulation for 4 min. Measurements were taken in the stenotic coronary artery and in a control vessel without obstructive disease. At a separate visit, peripheral blood flow at the popliteal artery (using duplex ultrasound assessment) and endothelial function assessed by peripheral artery tonometry (PAT) were measured at baseline and after one hour of nerve stimulation.

RESULTS

Compared to baseline, there was a significant increase in coronary blood flow as measured by average peak velocity (APV) in the control vessel with nerve stimulation (20.3 ± 7.7 to 23.5 ± 10 cm/s; p = 0.03) and non-significant increase in the stenotic vessel (21.9 ± 12 to 23.9 ± 12.9 cm/s; p = 0.23). Coronary flow reserve did not change significantly. Reactive hyperemia-peripheral arterial tonometry (Rh-PAT) increased from 2.28 ± 0.39 to 2.67 ± 0.6, p = 0.045.

CONCLUSIONS

A few minutes of peripheral nerve stimulation may improve coronary blood flow. This effect is more prominent in non-stenotic vessels. Longer stimulation improved endothelial function.

Two Cases of Transcutaneous Electrical Nerve Stimulation of the Common Peroneal Nerve Successfully Treating Refractory, Multifactorial Leg Edema

The treatment of leg edema often involves promoting venous blood flow but can be difficult in patients with comorbidities that prevent traditional management strategies such as limb elevation or mechanical compression devices. The geko device is a self-contained neuromuscular stimulation device that adheres to skin over the common peroneal nerve and delivers a low-voltage stimulus that activates the lower-leg musculature resulting in enhanced superficial femoral vein blood flow and velocity. Here we report 2 cases of multifactorial and refractory leg edema successfully treated with the geko device over a period of 4 to 16 weeks. The device also improved pain and chronic wound healing. Although the geko device is costly, it was well tolerated and may provide another treatment strategy for resistant leg swelling.

Short-term Outcomes of a Randomized Pilot Trial of 2 Treatment Regimens of Transcutaneous Tibial Nerve Stimulation for Fecal Incontinence

BACKGROUND

Fecal incontinence is a socially disabling condition that affects ≤15% of adults. Neuromodulatory treatments for fecal incontinence are now well established. Less invasive, cheaper, and more ambulatory forms of neuromodulation are under exploration.

OBJECTIVE

The purpose of this study was to assess the acceptability and safety of a new ambulatory tibial nerve stimulation device and to determine clinical effect size for 2 differing regimens of therapy.

DESIGN

This was a randomized, investigator-blinded, parallel-arm, 6-week pilot trial.

SETTINGS

The study was conducted at 7 United Kingdom trial centers. Patients were initially reviewed in the trial center, with subsequent applications of the device performed in the patients home setting.

PATIENTS

A total of 43 eligible patients (38 women) who failed conservative management of fecal incontinence were included in the study.

INTERVENTION

The study intervention involved twice-weekly, 1- versus 4-hour transcutaneous tibial nerve stimulation for 6 weeks (total of 12 treatments).

MAIN OUTCOME MEASURES

Standard fecal incontinence outcome tools (bowel diary, symptom severity score, and generic quality-of-life instruments) were used to collect data at baseline and at 2 weeks posttreatment cessation.

RESULTS

A total of 22 patients were randomly assigned to the 1-hour group and 21 to the 4-hour group. Improvements in fecal incontinence outcomes were observed for both groups, including median urge incontinence episodes per week at baseline and posttreatment (1-hour group 2.0 to 0.5 versus 4-hour group 4.0 to 1.0) and deferment time (1-hour group 2.0 to 2.0 minutes versus 4-hour group 0.5 to 5.0 minutes). Accompanying changes were observed in physical functioning domains of quality-of-life instruments. There were no adverse events, and the treatment was highly acceptable to patients.

LIMITATIONS

Limitations included the pilot design and lack of control arm in the study. Future trials would need to address these limitations.

CONCLUSIONS

This pilot study provides evidence that transcutaneous tibial nerve stimulation with a new ambulatory device is safe and acceptable for the management of fecal incontinence. Additional study is warranted to investigate clinical effectiveness.