Adjunctive mesenchymal stem/stromal cells augment microvascular function in poststenotic kidneys treated with low-energy shockwave therapy.

Effective therapeutic strategies are needed to preserve renal function in patients with atherosclerotic renal artery stenosis (ARAS). Low-energy shockwave therapy (SW) and adipose tissue-derived mesenchymal stem/stromal cells (MSCs) both stimulate angiogenesis repair of stenotic kidney injury. This study tested the hypothesis that intrarenal delivery of adipose tissue-derived MSCs would enhance the capability of SW to preserve stenotic kidney function and structure. Twenty-two pigs were studied after 16 weeks of ARAS, ARAS treated with a SW regimen (bi-weekly for 3 weeks) with or without subsequent intrarenal delivery of adipose tissue-derived MSCs and controls. Four weeks after treatment, single-kidney renal blood flow (RBF) before and after infusion of acetylcholine, glomerular filtration rate (GFR), and oxygenation were assessed in vivo and the renal microcirculation, fibrosis, and oxidative stress ex vivo. Mean arterial pressure remained higher in ARAS, ARAS + SW, and ARAS + SW + MSC compared with normal. Both SW and SW + MSC similarly elevated the decreased stenotic kidney GFR and RBF observed in ARAS to normal levels. Yet, SW + MSC significantly improved RBF response to acetylcholine in ARAS, and attenuated capillary loss and oxidative stress more than SW alone. Density of larger microvessels was similarly increased by both interventions. Therefore, although significant changes in functional outcomes were not observed in a short period of time, adjunct MSCs enhanced pro-angiogenic effect of SW to improve renal microvascular outcomes, suggesting this as an effective stratege for long-term management of renovascular disease.

Microvascular Effects of Pulsed Dye Laser in Combination With Oxymetazoline.

BACKGROUND AND OBJECTIVE: Oxymetazoline, an α-1A agonist, is approved by the United States Food and Drug Administration (FDA) for treatment of persistent facial erythema associated with rosacea and induces vasoconstriction by interacting with α receptors. The objective of our study was to study the microvascular effects of oxymetazoline and pulsed dye laser (PDL). MATERIALS AND METHODS: A dorsal window chamber was surgically installed on 20 mice. Each animal was assigned to one of four experimental groups: saline alone, oxymetazoline alone (10 µl applied once daily × 7 days), saline + PDL (saline applied 5 minutes before PDL irradiation [10 mm spot, 1.5 ms pulse duration, 7 J/cm2 delivered to epidermis]), or oxymetazoline + PDL (10 µl oxymetazoline applied 5 minutes before PDL and then once daily × 7 days). Brightfield and laser speckle imaging were performed for 7 days to monitor vascular architectural and functional changes. RESULTS: We observed persistent blood flow in all of the saline-only and oxymetazoline-only experiments. A higher rate of vascular shutdown was observed with oxymetazoline + PDL (66.7%) compared with saline + PDL alone (16.7%). Oxymetazoline application increased venule diameter at 5 minutes post-application and decreased both arteriole and venule diameters at 60 minutes post-application. CONCLUSION: The combination protocol of oxymetazoline + PDL induces persistent vascular shutdown observed 7 days after irradiation. This result may be associated with the acute vascular effects of oxymetazoline. Oxymetazoline + PDL should be evaluated as a treatment for cutaneous vascular disease, including rosacea and port wine birthmarks. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Peculiar Effects of Electromagnetic Millimeter Waves on Tumor Development in BALB/c Mice.

The study examined the effects of millimeter electromagnetic waves at a frequency of 130 GHz corresponding to the molecular absorption and radiation spectra of NO and O2 with the total exposition time of 6 h on tumor morphogenesis in 3- and 6-month-old tumor-prone BALB/c mice of both sexes. In experimental mice exposed to electromagnetic radiation, the development of cancer process was slowed down throughout the observation period; moreover, no macroscopic signs of the tumors were revealed. However, in contrast to control mice, experimental animals demonstrated the formation of pathological reactions reflected by hepatic biochemical indices accompanied by the development of dystrophic and microcirculatory alterations in the liver tissue.

Flow Induced Microvascular Network Formation of Therapeutic Relevant Arteriovenous (AV) Loop-Based Constructs in Response to Ionizing Radiation.

BACKGROUND The arteriovenous (AV) loop model enables axial vascularization to gain a functional microcirculatory system in tissue engineering constructs in vivo. These constructs might replace surgical flaps for the treatment of complex wounds in the future. Today, free flaps are often exposed to high-dose radiation after defect coverage, according to guideline-oriented treatment plans. Vascular response of AV loop-based constructs has not been evaluated after radiation, although it is of particular importance. It is further unclear whether the interposed venous AV loop graft is crucial for the induction of angiogenesis. MATERIAL AND METHODS We exposed the grafted vein to a single radiation dose of 2 Gy prior to loop construction to alter intrinsic and angio-inductive properties specifically within the graft. Vessel loops were embedded in a fibrin-filled chamber for 15 days and radiation-induced effects on flow-mediated vascularization were assessed by micro-CT and two-dimensional histological analysis. RESULTS Vessel amount was significantly impaired when an irradiated vein graft was used for AV loop construction. However, vessel growth and differentiation were still present. In contrast to vessel density, which was homogeneously diminished in constructs containing irradiated veins, vessel diameter was primarily decreased in the more peripheral regions. CONCLUSIONS Vascular luminal sprouts were significantly diminished in irradiated venous grafts, suggesting that the interposing vein constitutes a vital part of the AV loop model and is essential to initiate flow-mediate angiogenesis. These results add to the current understanding of AV loop-based neovascularization and suggest clinical implications for patients requiring combined AV loop-based tissue transfer and adjuvant radiotherapy.

Intraglandular Transplantation of Adipose-Derived Stem Cells for the Alleviation of Irradiation-Induced Parotid Gland Damage in Miniature Pigs.

PURPOSE: In a previous study, the authors verified the protective efficacy of adipose-derived stem cells (ADSCs) on the prevention of salivary gland (SG) damage induced by irradiation in mice. As a critical step before implementation in clinical practice, the present study investigated the protective effect of ADSCs in a miniature pig SG model, because miniature pigs share many characteristics with humans. MATERIALS AND METHODS: Third-passage autologous ADSCs at a concentration of 4 × 106 cells/mL were transplanted by intraglandular injection into parotid glands (PGs) immediately after local irradiation at a single dose of 20 Gy. The injection process was repeated twice a week for 6 consecutive weeks. At 12 weeks after irradiation, functional and histologic evaluations were performed by measuring salivary flow rate (SFR) and hematoxylin and eosin and periodic acid-Schiff staining. Immunohistochemical and transmission electron microscopic examinations also were conducted to evaluate amylase (AMY) production, microvessel density (MVD), and microstructural changes. RESULTS: The irradiated PGs showed remarkable decreases in SFR, AMY production, and MVD. However, transplantation of ADSCs alleviated irradiated PG morphology and function by preserving more functional acinar cells and increasing SFR and AMY production. In addition, greater MVD was observed in the ADSC-treated group than in the irradiated group. CONCLUSIONS: These results indicated that intraglandular transplantation of autologous ADSCs is an effective method to protect PGs against damage from irradiation in miniature pigs, which might have clinic application in the future.

The effect of LED on blood microcirculation during chronic wound healing in diabetic and non-diabetic patients-a prospective, double-blind randomized study.

Chronic wounds, especially in diabetic patients, represent a challenging health issue. Since standard treatment protocols often do not provide satisfactory results, additional treatment methods-like phototherapy using low-level light therapy-are being investigated. The aim of our study was to evaluate the effect of phototherapy with light-emitting diodes on chronic wound treatment in diabetic and non-diabetic patients. Since a sufficient blood supply is mandatory for wound healing, the evaluation of microcirculation in the healthy skin at a wound's edge was the main outcome measure. Forty non-diabetic patients and 39 diabetics with lower limb chronic wounds who were referred to the University Medical Center Ljubljana between October 2012 and June 2014 were randomized to the treated and control groups. The treated group received phototherapy with LED 2.4 J/cm2 (wavelengths 625, 660, 850 nm) three times a week for 8 weeks, and the control group received phototherapy with broadband 580-900 nm and power density 0.72 J/cm2. Microcirculation was measured using laser Doppler. A significant increase in blood flow was noted in the treated group of diabetic and non-diabetic patients (p = 0.040 and p = 0.033), while there was no difference in the control groups. Additional Falanga wound bed score evaluation showed a significant improvement in both treated groups as compared to the control group. According to our results, phototherapy with LED was shown to be an effective additional treatment method for chronic wounds in diabetic and non-diabetic patients.

[The application of low-frequency ultrasound for the comprehensive treatment and rehabilitation of the patients presenting with chronic endometritis]. / Primenenie nizkochastotnogo ul'trazvuka v kompleksnoi terapii i reabilitatsii patsientok s khronicheskim éndometritom.

The incidence of chronic endometritis remains rather high despite considerable progress in reproductive medicine including the advent of the new methods for assisted reproduction; the pregnancy rate after the treatment of this condition is still unacceptably low. It implies the necessity of the careful preparation of endometrium for the implantation of the embryo especially in women with a history of unsuccessful outcomes of the IVF treatment. It calls for the development of the efficient therapeutic modalities for the management of chronic endometritis and restoration of the normal reproductive function; their introduction into the therapeutic algorithm remains equally relevant. The characteristic features of chronic endometritis include blood circulatory disorders in the vessels of the uterus and in the pelvic vascular basin, changes of local immunity in the endometrium concomitant with the activation of cellular and humoral responses of inflammation in the form of enhanced leukocyte infiltration and increased production of cytokines. The long duration of such a process results in the development of fibrosis that, in its turn, leads to chronic tissue hypoxia, potentiation of inflammation, and disruption of decidualization that hampers successful implantation. The article shows the possibility of using low-intensity ultrasound for the treatment and rehabilitation of the patients presenting with chronic endometritis. The data concerning the primary biophysical processes developing in the tissues under the influence of ultrasound are discussed. The therapeutic effects and their underlying mechanisms and described. The physiotherapeutic treatment considerably improved vascular hemodynamics in the pelvic basin and produced trophotropic, defibrosing, and anti-inflammatory effects. The clinical data giving evidence of the high effectiveness of the application of intrauterine ultrasound cavitation provide a basis for the recommendation to include this physical factor in the existing algorithms for the pre-gravid preparation of the women presenting with disorders of the reproductive function and chronic endometritis.

Effects of pulsed electromagnetic fields on peripheral blood circulation in people with diabetes: A randomized controlled trial.

Cutaneous blood flow provides nourishment that plays an essential role in maintaining skin health. We examined the effects of pulsed electromagnetic fields (PEMFs) on cutaneous circulation of dorsal feet. Twenty-two patients with diabetes mellitus (DM) and 21 healthy control subjects were randomly allocated to receive either PEMFs or sham PEMFs (0.5 mT, 12 Hz, 30 min). Blood flow velocity and diameter of the small vein were examined by using ultrasound biomicroscopy; also, microcirculation at skin over the base of the 1st metatarsal bone (Flux1) and distal 1st phalange (Flux2) was measured by laser Doppler flowmetry before and after intervention. Results indicated that PEMFs produced significantly greater changes in blood flow velocity of the smallest observable vein than did sham PEMFs (both P < 0.05) in both types of subjects. However, no significant difference was found in changes of vein diameter, nor in Flux1 and Flux2, between PEMFs and sham PEMFs groups in subjects with or without DM. We hypothesized that PEMFs would increase blood flow velocity of the smallest observable vein in people with or without DM. Bioelectromagnetics. 37:290-297, 2016. © 2016 Wiley Periodicals, Inc.

Functional Features of Microcirculation System and its Possibilities of Oxygen Transport in Children and Youths of Bryansk Region in Conditions of Radioecological Pressure.

The questions of influence of low radiation doses on microcirculation of blood in ontogeny of males from 7 to 27 years are presented in the article. Using the method of laser Doppler ultrasounds, optical oximetry and laser fluorescent diagnostics, we studied the blood perfusion level in the microcirculation system of 315 schoolchildren and students, considered the regulation mechanisms of microcirculation, the level of oxygen saturation of hemoglobin both in the circulation system and mixed blood, the index of oxygen utilization in tissues and the value of fluorescent use of oxygen. We received the information about the changes in the frequency of occurrence of different microcirculation types associated with the age and region of residence. In the case of higher radiation levels we marked a significant increase of individuals with the "extreme" microcirculation type (hypoemic and hyperemic) against the background of the decreased mesoemic type. A special feature of the metabolism process in children, teenagers, and youths is a decrease of the microcirculation density with an increase of the myogenic tone of metaarterioles and precapillary sphincters. The tone of arterioles grows with age. As a result of the limited blood volume, oxygen. is pulled compensatory from blood in larger amounts; it is shown from a significant decrease of the level of oxygen saturation in mixed blood. The strongest differences are shown for the hypoemic and hyperemic microcirculation type. Dwelling on the areas with radio-ecological pressure is accompanied by an increase in the fluorescent index of oxygen use. The level of the total oxygen use in these individuals is higher than in those living in radiation favorable areas.

Remote effects of extracorporeal shock wave therapy on cutaneous microcirculation.

BACKGROUND: Extracorporeal shock wave treatment (ESWT) has proven its clinical benefits in different fields of medicine. Tissue regeneration and healing is improved after shock wave treatment. Even in the case of burn wounds angiogenesis and re-epithelialization is accelerated, but ESWT in extensive burn wounds is impracticable. HYPOTHESIS: High energy ESWT influences cutaneous microcirculation at body regions remote from application site. METHODS: Eighteen Sprague Dawley rats were randomly assigned to two groups and received either high energy ESWT (Group A: total 1000 impulses, 10 J) or placebo shock wave treatment (Group B: 0 impulses, 0 J), applied to the dorsal lower leg of the hind limb. Ten minutes later microcirculatory effects were assessed at the contralateral lower leg of the hind limb (remote body region) by combined Laser-Doppler-Imaging and Photospectrometry. RESULTS: In Group A cutaneous capillary blood velocity was significantly increased by 152.8% vs. placebo ESWT at the remote body location (p = 0.01). Postcapillary venous filling pressure remained statistically unchanged (p > 0.05), while cutaneous tissue oxygen saturation increased by 12.7% in Group A (p = 0.220). CONCLUSION: High energy ESWT affects cutaneous hemodynamics in body regions remote from application site in a standard rat model. The results of this preliminary study indicate that ESWT might be beneficial even in disseminated and extensive burn wounds by remote shock wave effects and should therefore be subject to further scientific evaluation.

[The influence of the low-frequency laser radiation on microcirculatory disorders in the patients presenting with chronic viral hepatitis].

AIM: The objective of the present study was to elucidate the character of microcirculatory disorders in the patients presenting with chronic viral hepatitis and to evaluate the possibilities for the correction of the associated disorders with the use of laser irradiation. Material and methods. All the patients were divided into three groups. Group 1 was comprised of 30 patients who were treated by means of traditional medicamental therapy alone; they served as controls. Group 2 consisted of 45 patients treated by intravenous laser irradiation in addition to traditional medicamental therapy. The patients of group 3 (n=45) received a course of laser skin treatment. The state of microcirculation was assessed by the laser Doppler flowmetry (LDF) technique with the help of a LAKK-02 apparatus (<> Research and Manufacturing Complex, Moscow, Russia). RESULTS: The study has demonstrated heterogeneity of the types of microcirculation with the statistically significant increase in the frequency of its pathological cases. All the patients treated with the use of low-intensity laser therapy exhibited a significant improvement of the blood flow characteristics regardless of the initial hemodynamic type of microcirculation. CONCLUSION: It is concluded that the application of laser irradiation as a component of the combined treatment of the patients presenting with chronic viral hepatitis facilitates correction of microcirculatory disorders.

[FIRST EXPERIENCE OF APPLICATION OF TECHNOLOGY OF A TWO-STREAM LOW-FREQUENCY ULTRASOUND TECHNOLOGY IN ABDOMINAL SURGERY].

Biophysical peculiarities of action on tissues of a two-strem low-frequency ultrasound (TSLFU) technology, elaborated by "Arobella Medical LLC" (USA) firm, were studied. Capacity of ultrasound to separate a pathologically-changed and healthy tissues, to divide the structures in accordance to their bioacoustical parameters constitutes the technology peculiarities. The presence of such a biophysical effect permits to achieve high resectability (R0) in patients with oncological diseases. Antibacterial effect and stimulation of intraorgan microcirculation with ultrasound irradiation were noted. Biophysical peculiarities of TSLFU were successfully applied in surgical treatment of 48 patients, suffering inflammatory and oncological diseases of the abdominal cavity organs.

A comparison of microvascular responses to visible and near-infrared lasers.

BACKGROUND AND OBJECTIVE: Pulsed dye laser (PDL) is a commonly used treatment for Port Wine Stain birthmarks (PWS). However, deeper components of PWS are often resistant to PDL. Deeper penetrating lasers, including the long pulsed Neodymium:Yttrium Aluminum Garnet (Nd:YAG) laser have been used, but carry greater risk. This study evaluates the distinct blood vessel thermal responses to visible (595 nm) and near infrared (1,064 nm) lasers using animal and numerical models. STUDY DESIGN/MATERIALS AND METHODS: Blood vessels in the rodent dorsal skin chamber (DSC) were irradiated by a 595 nm PDL and a long-pulsed 1,064 nm Nd:YAG laser. Laser-induced immediate and 1-hour post-structural and functional changes in the vessels were documented. Numerical simulations were conducted using a 1,000 µm depth SD mouse skin fold to simulate experimental conditions. RESULTS: PDL irradiation produced immediate blood vessel hemorrhage. Modeling indicated this occurs due to preferential heating of the superior parts of large blood vessels. Nd:YAG irradiation resulted in blood vessel constriction; modeling indicated more uniform heating of vessel walls. CONCLUSION: PDL and Nd:YAG lasers result in distinct tissue responses. This supports different observable clinical treatment end points when using these devices. Vessel constriction associated with the Nd:YAG may be more difficult to observe and is one reason this device may carry greater risk.

Study of microcirculation of the ocular ciliary body in experimental kidney disease.

We studied disorders in ciliary body microcirculation in experimental chronic glomerulonephritis with tubulointerstitial nephritis and evaluated the hemodynamic effects of low-frequency pulsed electromagnetic field in this pathology. Laser Doppler flowmetry demonstrated vasospasm with reduced nutrient blood fl ow in the ciliary body of animals with experimental chronic glomerulonephritis with tubulointerstitial nephritis. The exposure to low-frequency pulsed electromagnetic field using developed technology will lead to significant reduction of the vascular tone and improve arterial blood supply to the microcirculatory bed.

Skin perfusion and oxygen saturation after mastectomy and radiation therapy in breast cancer patients.

The pathophysiological mechanism behind complications associated with postmastectomy radiotherapy (PMRT) and subsequent implant-based breast reconstruction are not completely understood. The aim of this study was to examine if there is a relationship between PMRT and microvascular perfusion and saturation in the skin after mastectomy and assess if there is impaired responsiveness to a topically applied vasodilator (Methyl nicotinate - MN). Skin microvascular perfusion and oxygenation >2 years after PMRT were measured using white light diffuse reflectance spectroscopy (DRS) and laser Doppler flowmetry (LDF) in the irradiated chest wall of 31 women with the contralateral breast as a control. In the non-irradiated breast, the perfusion after application of MN (median 0.84, 25th-75th centile 0.59-1.02 % RBC × mm/s) was higher compared to the irradiated chest wall (median 0.51, 25th-75th centile 0.21-0.68 % RBC × mm/s, p < 0.001). The same phenomenon was noted for saturation (median 91 %, 25th-75th centile 89-94 % compared to 89 % 25th-75th centile 77-93 %, p = 0.001). Eight of the women (26%) had a ≥10 % difference in skin oxygenation between the non-irradiated breast and the irradiated chest wall. These results indicate that late microvascular changes caused by radiotherapy of the chest wall significantly affect skin perfusion and oxygenation.

Is the effect of mobile phone radiofrequency waves on human skin perfusion non-thermal?

OBJECTIVE: To establish whether SkBF can be modified by exposure to the radiofrequency waves emitted by a mobile phone when the latter is held against the jaw and ear. METHODS: Variations in SkBF and Tsk in adult volunteers were simultaneously recorded with a thermostatic laser Doppler system during a 20-minute "radiofrequency" exposure session and a 20-minute "sham" session. The skin microvessels' vasodilatory reserve was assessed with a heat challenge at the end of the protocol. RESULTS: During the radiofrequency exposure session, SkBF increased (vs. baseline) more than during the sham exposure session. The sessions did not differ significant in terms of the Tsk time-course response. The skin microvessels' vasodilatory ability was found to be greater during radiofrequency exposure than during sham exposure. CONCLUSIONS: Our results reveal the existence of a specific vasodilatory effect of mobile phone radiofrequency emission on skin perfusion.

Polarized light spectroscopy for measurement of the microvascular response to local heating at multiple skin sites.

OBJECTIVE: To evaluate whether TiVi, a technique based on polarized light, could measure the change in RBC concentration during local heating in healthy volunteers. METHODS: Using a custom-made transparent heater, forearm skin was heated to 42 °C for 40 minutes while the change in RBC concentration was measured with TiVi. The perfusion response during local heating was measured at the same time with Laser Doppler flowmetry. RESULTS: Mean RBC concentration increased (91 ± 34 vs. 51 ± 34 A.U. at baseline, p < 0.001). The spatial heterogeneity of the RBC concentration in the measured skin areas was 26 ± 6.4% at baseline, and 23 ± 4.6% after 40 minutes of heating. The mean RBC concentrations in two skin sites were highly correlated (0.98 at baseline and 0.96 after 40 minutes of heating). The change in RBC concentration was less than the change in perfusion, measured with LDF. Unlike with LDF, a neurally mediated peak was not observed with TiVi in most of the test subjects. CONCLUSIONS: TiVi is a valuable technique for measuring the microvascular response to local heating in the skin, and offers a high reproducibility for simultaneous measurements at different skin sites, provided carefully controlled experiments are ensured.

[Molecular-cellular mechanisms of light radiation and weak magnetic fields on the blood status and microcirculation system (at therapeutic doses) with using modern magnetolaser equipment (review of the literature)].

This review covers the molecular-cellular mechanisms of therapeutic action of light and magnetic field on blood components, blood vessels and the microcirculation system. Noted the role of the magnetic field as a trigger of vasodilation/vasoconstriction, depending on the initial vascular tone. Discussed the importance of NO-dependent effects of magnetic field on the microcirculatory response and angiogenesis.

The impact of hyperbaric oxygen therapy on late irradiation injury in oral microcirculation.

BACKGROUND: Late side effects of radiotherapy in patients with head and neck cancer (HNCPs) result in decreased tissue vascularity, a compromised healing capacity and spontaneous breakdown of tissue. The aim of this study was to examine the in vivo effect of hyperbaric oxygen therapy (HBOT) on the microcirculation in irradiated oral tissue. METHODS: Using a handheld microscope, the effect of HBOT on oral mucosal microcirculation parameters was measured in 34 previously irradiated HNCPs prior to HBOT and at 4 weeks and 6 months posttreatment. RESULTS: A significant increase in mean buccal vessel density and decrease in buccal vessel diameter was found 6 months after HBOT compared to baseline, 22 ± 11 versus 25 ± 7 cpll/mm2 (p < 0.05) and 20 ± 4 versus 16 ± 5 µm (p < 0.05), respectively. CONCLUSION: Our results indicate that oral microcirculation histopathology associated with irradiation is able to respond to HBOT by redirecting oral microcirculation parameters towards values consistent with healthy tissue.

Noninvasive cutaneous blood flow as a response predictor for visible light therapy on segmental vitiligo: a prospective pilot study.

BACKGROUND: Visible light is a treatment option for segmental vitiligo (SV), and visible light-induced repigmentation is associated with normalization of sympathetic dysfunction. Currently, it is difficult to predict individual patients' response to visible light therapy. OBJECTIVES: To test whether cutaneous blood flow can serve as a response predictor for visible light on treating SV. METHODS: Fourteen patients with SV were recruited in this prospective pilot study. Laser Doppler flowmetry was used to evaluate the cutaneous blood flow over SV lesions and contralateral normal skin. The pretreatment blood flow evaluation consisted of two stages: stage 1, following cold stress without prior visible light irradiation, and stage 2, following cold stress with prior visible light irradiation. Subsequently, the patients received regular visible light treatment for 3months, and a comparison of the pretreatment blood flow patterns between the visible light responding and nonresponding groups was carried out at the end of the study period. RESULTS: The SV lesions showed different blood flow profiles as compared with the contralateral normal skin. At the end of the 3-month study period, seven (50%) patients showed clinical repigmentation of >25%. The visible light responding group showed a more consistent occurrence of increased blood flow after stage 2 of the pretreatment evaluation while the nonresponding counterpart showed no significant changes. CONCLUSIONS: Normalization of sympathetic dysfunction may account for the efficacy of visible light in treating SV. Evaluation of cutaneous blood flow with and without prior visible light irradiation on cold-stressed SV lesions may serve as a treatment response predictor.