NAERINGSPH-Nærings-phd

Patients with insufficient arterial blood flow to the lower extremities experience pain during ambulation, wounds which are difficult to heal, and reduced physical mobility and quality of life. Vascular surgery, balloon angioplasty or amputation is often the next step. While these treatments provide temporary relief, restenosis rates are high, treatments are costly, and disease progression often continues unabated. Sundby and colleagues have in this thesis studied the effects of applying mild intermittent negative pressure (-40mmHg) to the limb on foot macro- and microcirculation in healthy volunteers, patients with peripheral arterial disease, and people with spinal cord injury. The main objectives of this thesis were to explore the acute effects of lower limb intermittent negative pressure on foot arterial and cutaneous blood flow, and to explore the effects of intermittent negative pressure on ulcer healing in patients with chronic leg and foot ulcers. The results of this PhD thesis demonstrated an immediate and significant effect of negative pressure on foot macro- and microcirculation. Further, constant negative pressure applied to the lower limb decreases foot circulation, while the same negative pressure applied intermittently induced increased arterial and cutaneous blood flow of the foot. A case study on patients with peripheral arterial disease suggested that intermittent negative pressure improves ulcer healing and foot perfusion. Further, a randomized controlled pilot study on spinal cord injured individuals with chronic leg and foot ulcers indicated that intermittent negative pressure combined with standard wound care improves ulcer healing compared to standard wound care alone. This thesis adds novel data about the use of a non-invasive method to increase arterial and cutaneous blood flow in the lower limb to treat poor circulation and chronic lower leg and foot ulcers. Larger randomized controlled trials are warranted to confirm the initial clinical findings.

Peripheral arterial occlusive disease (PAOD) is a condition characterized by atherosclerotic occlusive disease of the arterial blood vessels to the lower extremities. As a result, all individuals with PAOD are at an enlarged risk of cardiovascular morbidi ty and mortality. The clogged arteries restrict blood flow to the leg muscles, leading to excruciating pain, cramping, or aching in the calves, thighs, or buttocks that appears during exercise and is relieved by rest. The options for treatment of PAOD inc lude medical treatment or intervention/revascularization (endovascular or open reconstruction). Besides supervised exercise, which is a major treatment modality for patients with PAOD, there have been very few significant breakthroughs in the treatment of PAOD. Endovascular treatment and surgery of lesions above the level of the groin show good long-term results, while the results of intervention below the level of the groin are significantly lower. Additionally, significant proportions of patients have i noperable vascular disease because of co-morbidities such as cerebrovascular and coronary heart disease which contraindicate surgical intervention. Hence, there is an urgent need for new treatments. Otivio has developed a non-invasive method designed to i ncrease blood flow to an extremity. The aim of the present project is to test the effects of the new method to increase peripheral blood flow in healthy controls and in patients with PAOD.