Post on 02-Mar-2018
Abs
trac
t
Mild nega*ve oscilla*ng pressure pulses (NPP) applied to a limb of a pa*ent improves blood flow to the limb and to the skin. Pa*ents suffering from peripheral arterial occlusive disease (PAOD) may benefit from a transient increase in blood flow to reduce pain and facilitate wound healing. A novel device (FlowOx™) has been developed, and tested on pa*ents with reduced peripheral circula*on. The NPP technology improved blood flow to the skin of the toes of pa*ents with PAOD grade 2 or 3 (Fontaine classifica*on) with about 60% (n=8, P< 0.05).
Main points: • A new device (FlowOx™) was developed which could be used to treat pa*ents with reduced peripheral circula*on. • The system consists of a rigid boot, with internal padding to prevent pressure points on the leg and skin. • NPP consists of a pressure of -‐40 mmHg for 10 seconds and 7 seconds of atmospheric pressure. • These oscilla*ng nega*ve pressure pulses induced an increase in skin blood flow of the toes of about 60% (n=8, P<0,05,median, two-‐sided paired Wilcoxon test).
Conclusion: NPP applied by a FlowOx™ boot may be used to enhance skin blood flow of the toes in pa*ents with reduced peripheral circula*on. There is also a trend (not sta*s*cally significant) towards increased circula*on in other skin areas. Further studies need to be carried out to evaluate the effect of NPP in pa*ents with reduced peripheral circula*on. It will be important to look at long term effects to understand implica*on for wound healing. .
Blood flow measurements from one pa*ent using 3 probes places at the calf (a), the foot (b) and on the toe (c), (d) is the measurement of the pressure inside the device. The nega*ve pressure pulses (-‐40 mmHg)lasted for 10 seconds with 7 seconds normal (atmospheric) pressure. Higher levels of nega*ve pressure (-‐60 & -‐80 mmHg was also tested but did not show a sta*s*cal significant increase in blood flow compared to baseline (data not shown).
Financial support from: Grant; FP7-‐SME-‐2011: 286709 (EU) Grant, RFF -‐ 217598 / 97230 (Norwegian Research Fund) Project Partners: Cambridge Design Partnership, UK IBV, Valencia, Spain EMO, Valencia, Spain Solann AB, Sweden Duncan Stang, Lanarkshire Hospital, Scotland Lørenskog Nursing Home, Lørenskog, Norway Disclosures: Iacob Mathiesen is the CEO and shareholder in O*vio AS Contact: im@o*vio.com
Acknowledgements/Disclosures
Intr
oduc
tion
Mat
eria
ls &
Met
hods
Res
ults
Con
clus
ion FlowOx -‐ A Novel Device for Improving Blood Flow to Ischemic Feet?
Inger Helene Nådland1 (PhD), Iacob Mathiesen2 (PhD), Jarlis Wesche1 (MD, PhD) 1Aksershus University Hospital, Sykehusveien 25, 1478 Lørenskog, Norway; 2O*vio AS, Gaustadalleen 21, 0349 Oslo, Norway
The op*ons for treatment of PAOD include medical treatment and interven*on /revasculariza*on (endovascular angioplasty (PTA) or open reconstruc*on). Treatment also involve ambulatory exercise, modifica*on of risk-‐factors such as smoking cessa*on, change in diet, medica*on etc. Endovascular treatment consists of angioplasty of obstruc*ons, with or without concomitant stent-‐implanta*on. There are many pa*ents, however, who are too fragile to undergo interven*on/surgery or to do physical exercise. These pa*ents could benefit from a device to be used at home to transiently improve blood flow and oxygena*on of the skin.
Dis
cuss
ion
Further work must be done to evaluate if a transient increase in blood flow can induce long las*ng benefits to the pa*ents. It may be that transient increase in blood flow and oxygena*on will improve wound healing, reduc*on in rest pain and poten*ally allow revasculariza*on to occur. Further studies are warranted.
Changes in blood flow values in individual pa*ents ( measured on the toes). The median increase was 60% and sta*s*cally different from baseline measurements (n=8, p<0.05).
Subgroup Inclusion criteria Exclusion criteria 1. Pa*ents with PAOD Clinically verified PAOD grade 2 Demen*a Fontaine grade 2 (Ankle-‐Brachial Pressure index <0,9) Fever (above 38 C°) (Intermioent claudica*on) Age 30-‐90 years Severe COPD Able to give informed consent Severe heart disease* 2. Pa*ents with PAOD Clinically verified PAOD grade 3 Demen*a Fontaine grade 3 (Ankle-‐Brachial Pressure index <0,4, Fever (above 38 C°) (Cri*cal limb ischemia Ultrasound, CT/MR angiography) Severe COPD with rest pain) Presence of rest pain Severe heart disease* Age 30-‐90 years Able to give informed consent 3. Pa*ents with PAOD Clinically verified PAOD grade 4 Demen*a Fontaine grade 4 (Ankle-‐Brachial Pressure index <0,4, Fever (above 38 C°) (Cri*cal limb ischemia Ultrasound, CT/MR angiography) Severe COPD with rest pain and/or ulcer/ Presence of rest pain, ulcer/gangrene Severe heart disease* gangrene Age 30-‐90 years Able to give informed consent
Blood flow was measured using PeriFlux System 5000 laser Doppler probes. The system allows a non-‐invasive, con*nuous, real *me measurement of the microcircula*on (small arteries, capillaries and small veins). A clinical trial was performed on 8 pa*ents selected according to the criteria in the table (right). 1
a
b
c
d
A new FlowOx™ boot and nega*ve pressure pulse generator has been developed. The system is able to apply nega*ve pressure pulses to the limbs of pa*ents without the crea*on of pressure points. The experimental cycle consisted of 5 minutes of measurements without pulsing, followed by 5 minutes with pulsing before the final 5 minutes without pulsing.