PWRR reinforces PWS as a biomechanical rupture risk index. The ILT has a major impact on AAA biomechanics and rupture risk, and hence, needs to be considered in meaningful FE simulations. The applied FE models, however, could not explain rupture in all analysed aneurysms.

2Deep vein thrombosis is a common complication when immobilising the lower limb after surgery. We hypothesised that adjuvant intermittent pneumatic compression (IPC) during post-operative outpatient immobilisation of the lower limb could reduce the incidence of deep vein thrombosis (DVT).A total of 150 patients with acute Achilles tendon rupture were randomised to either treatment with IPC for six hours daily (n = 74) under an orthosis or treatment as usual (n = 74) in a plaster cast. At two weeks post-operatively the incidence of DVT was assessed using compression duplex ultrasound (CDU) by two ultrasonographers blinded to treatment.After the IPC intervention had ended, all patients were immobilised in the orthosis for another four weeks and a second CDU was performed.Trial registration: www.clinicaltrials.gov; NCT01317160.At two weeks the DVT rate was 21% in the IPC group and 38% in the control group (OR = 2.36; 95% CI 1.11 to 5.01). Age > 39 years was found to be a strong risk factor for DVT (OR = 4.84; 95% CI 2.14 to 10.96). Treatment with IPC corrected for age reduced the risk significantly (OR = 0.36; 95% CI 0.16 to 0.80). At six weeks, however, the frequency of DVT was 49% in the IPC group and 51% in the control group (OR = 0.94; 95% CI 0.49 to 1.83).IPC seems to be an effective method of reducing the risk of early DVT in legimmobilised outpatients. A high risk of DVT during prolonged immobilisation warrants further study. 3

Abdominal Aortic Aneurysms (AAAs), i.e., focal enlargements of the aorta in the abdomen are frequently observed in the elderly population and their rupture is highly mortal. An intra-luminal thrombus is found in nearly all aneurysms of clinically relevant size and multiply affects the underlying wall. However, from a biomechanical perspective thrombus development and its relation to aneurysm rupture is still not clearly understood. In order to explore the impact of blood flow on thrombus development, normal aortas (n = 4), fusiform AAAs (n = 3), and saccular AAAs (n = 2) were compared on the basis of unsteady Computational Fluid Dynamics simulations. To this end patient-specific luminal geometries were segmented from Computerized Tomography Angiography data and five full heart cycles using physiologically realistic boundary conditions were analyzed. Simulations were carried out with computational grids of about half a million finite volume elements and the Carreau-Yasuda model captured the non-Newtonian behavior of blood. In contrast to the normal aorta the flow in aneurysm was highly disturbed and, particularly right after the neck, flow separation involving regions of high streaming velocities and high shear stresses were observed. Naturally, at the expanded sites of the aneurysm average flow velocity and wall shear stress were much lower compared to normal aortas. These findings suggest platelets activation right after the neck, i.e., within zones of pronounced recirculation, and platelet adhesion, i.e., thrombus formation, downstream. This mechanism is supported by recirculation zones promoting the advection of activated platelets to the wall.

Since Achilles tendon healing is protracted, more knowledge of metabolites known to meet the demands for biosynthesis and proliferation is needed. We hypothesized that essential metabolites, glutamate, glucose, lactate, pyruvate and glycerol, are present and upregulated in healing Achilles tendons. We moreover hypothesized that adjuvant intermittent pneumatic compression (IPC), which increases blood flow, upregulates metabolite concentrations. Twenty patients with acute Achilles tendon rupture were recruited, operated, and included. The control group, 15 patients, received plaster cast immobilization, while five patients received adjuvant foot IPC beneath the plaster cast. At 2 weeks postoperatively, microdialysis of the healing and contralateral intact Achilles tendons was followed by quantification of metabolites. Healing compared to intact tendons of the controls exhibited significantly increased concentrations (mM) of glutamate (60 ± 14 vs 20 ± 11), lactate (1.15 ± 0.60 vs 0.64 ± 0.35), and pyruvate (81 ± 29 vs 35 ± 25, μM). Healing tendons of the IPC vs control group displayed higher levels of glutamate (84 ± 15 vs 62 ± 16) and glucose (3.44 ± 0.62 vs 2.62 ± 0.72); (P < 0.05) and trends toward higher concentrations of pyruvate, lactate, and glycerol (P < 0.10). The present study demonstrates that early Achilles tendon repair entails and upregulates local essential metabolites. This metabolic response can, during tendon healing with plaster cast immobilization, be promoted by adjuvant IPC.

These results suggest that the cardioprotective effect of the PPARgamma agonist rosiglitazone is mediated via NO by phosphorylation of eNOS.