Objective-The role of fluid shear stress (FSS) in collateral vessel growth remains disputed and prospective in vivo experiments to test its morphogenic power are rare. Therefore, we studied the influence of FSS on arteriogenesis in a new model with extremely high levels of collateral flow and FSS in pig and rabbit hind limbs. Methods and Results-A side-to-side anastomosis was created between the distal stump of one of the bilaterally occluded femoral arteries with the accompanying vein. This clamps the collateral reentry pressure at venous levels and increases collateral flow, which is directed to a large part into the venous system. This decreases circumferential wall stress and markedly increases FSS. One week after anastomosis, angiographic number and size of collaterals were significantly increased. Maximal collateral flow exceeded by 2.3-fold that obtained in the ligature-only hind limb. Capillary density increased in lower leg muscles. Immunohistochemistry revealed augmented proliferative activity of endothelial and smooth muscle cells. Intercellular adhesion molecule-1 and vascular cell adhesion molecule (VCAM)-1 were upregulated, and monocyte invasion was markedly increased. In 2-dimensional gels, actin-regulating cofilin1 and cofilin2, destrin, and transgelin2 showed the highest degree of differential regulation. Conclusions-High levels of FSS cause a strong arteriogenic response, reinstate cellular proliferation, stimulate cytoskeletal rearrangement, and normalize maximal conductance. FSS is the initiating molding force in arteriogenesis. Key Words: fluid shear stress Ⅲ shunt Ⅲ arteriogenesis Ⅲ proteomics Ⅲ cytoskeletal proteins N umerous studies have documented the influence of fluid shear stress (FSS) as an arterial molding force, 1-3 but information on the actions of markedly increased in vivo FSS on the development of arterial collateral vessels after occlusion of a conduit artery is lacking. Such studies are needed because attempts at changing FSS often also alter the circumferential wall stress, another acknowledged molding force of growing collateral vessels. The formation of a collateral circulation after an arterial occlusion correlates well with the calculated increase in FSS because of the increased collateral flow caused by the pressure decrease along pre-existent collaterals. However, because of the fast increase in collateral diameter by cellular proliferation, FSS decreases quickly again, and the early termination of the growth process at an incomplete stage of adaptation is believed to be caused by the only transient action of FSS. One of the hypotheses to be tested was, therefore, whether prolonged action of FSS would also improve the final adaptation by continued growth. The present experiments were therefore undertaken to prospectively study the causal relations between arteriogenesis and FSS by a stepwise and lasting increase of collateral flow brought about by the creation of a side-to-side anastomosis between the distal stump of the occluded femoral artery and its accompanying vei...

We report the primary and long-term outcome of patients with selected TransAtlantic Inter-Society Consensus (TASC) C or D lesions of the iliac arteries after percutaneous interventional reconstruction. Between 1999 and 2001, 89 patients with peripheral arterial disease categorized as TASC C (n=37) and D (n=52) underwent percutaneous interventional reconstruction and stent implantation. Patients were followed for 1-62 months (mean 36 months). Patency rates were assessed by Duplex ultrasound and ankle-brachial index (ABI) measurement. The primary technical success rate was 96.9% with an overall complication rate of 5.6%. The ABI improved from an average of 0.51+/-0.15 before intervention to 0.79+/-0.16 on the day following intervention and to 0.81+/-0.17 within 3 years after intervention. Clinical improvement was observed in 97.3% of the patients in the TASC C group and in 88.5% in the TASC D group. Eighty of 89 patients (89.9%) remained patent at 3-year follow-up. In five patients the reintervention was successful. The secondary patency rate was 95.5%. The patency rates were similar in our selected TASC C and D patients to those so far published for TASC A and B, with low complication rates. Therefore, percutaneous intervention can be recommended for these patients.

We report the primary and mid-term outcome of patients with long chronic iliac artery occlusions after percutaneous excimer-laser-assisted interventional recanalization. Between 2000 and 2001, 43 patients with 46 chronic occlusions of either the common iliac artery (n=27), the external iliac artery ( n=13) or both (n=3) underwent laser-assisted percutaneous transluminal angioplasty and implantation of stents. The average length of the occlusion was 57.1+/-26 mm. After laser-assisted angioplasty and implantation of a total of 60 stents, the patients were followed up for up to 4 years. Patency rates were analyzed by ankle-brachial index (ABI) measurement and duplex ultrasound. The primary technical success rate was 95.3%, with a major complication rate of 6.9%. Clinical improvement as categorized by the Rutherford guidelines could be observed in 97.6% of cases. The ABI of all patients improved from an average of 0.46+/-0.08 before intervention to 0.97+/-0.13 at the end of the follow-up period. The overall primary patency rate was 86.1%. Four reinterventions were successful (secondary patency rate 95.4%). The mid-term results of the percutaneous recanalization of iliac artery occlusions with primary and secondary patency rates of 86.1 and 95.4% are similar to those of the treatment of short stenoses.

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