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Objectives: We investigated the time course of stent patency in the femoro-popliteal artery for as long as 4 years. Background: Stent fracture has been related to poor 2-year patency in the femoro-popliteal artery. Methods: We studied 239 consecutive patients who underwent provisional de novo stenting with nitinol stents for 333 limbs (Luminexx stent [C. R. Bard, Inc., Murray Hill, New Jersey] in 91 limbs; Smart stent [Cordis Corp., Miami Lakes, Florida] in 242 limbs) from April 2004 to December 2007. Stent fracture was determined by X-ray with multiple projections. Patency was assessed by duplex ultrasonography as peak systolic velocity ratio <2.4 or by angiography (% diameter stenosis <50%). Primary patency in those with and without stent fracture at follow-up was assessed along with factors influencing stent fracture. Results: Primary patency was 81%, 74%, 68%, and 65% at 1, 2, 3, and 4 years, respectively. Stent fracture occurred in 14% (78 of 544) per stent and 17% (55 of 333) per limbs. Stent fracture was significantly associated with multiple stent deployments (with fracture = 2.3 ± 0.9 stents vs. without fracture = 1.5 ± 0.7 stents, p < 0.001) and long lesions (with fracture = 208 ± 84 mm vs. without fracture = 121 ± 79 mm, p < 0.001). Primary patency was 68% with fracture versus 83% without fracture at 1 year, p = 0.03; 65% versus 75% at 2 years, p = 0.05; 61% versus 69% at 3 years, p = 0.06; and 61% versus 65% at 4 years, p = 0.07. Neither type 1 nor type 3 fracture affected patency, although type 2 showed the worst patency. Conclusions: Stent fracture worsened the patency during the first 2 years, but it did not apparently affect patency beyond 2 years. In particular, complete stent separation did not affect patency. [Copyright &y& Elsevier]

Introduction: Measurement of the fractional flow reserve (FFR) or vascular flow reserve (VFR) is a feasible approach to diagnose a peripheral arterial physiological condition. However, maximal hyperemic response, leading to examination of Doppler flow velocity and stenosis resistance, in lower-limb lesions is not well understood. Hypothesis: We assessed the hypothesis that VFR and stenosis resistance predict stenosis severity in peripheral artery disease. Methods: Twenty four limbs (men 67%, age 74 years) with focal stenosis of the superficial femoral artery (SFA) were analyzed. We excluded critical limb ischemia, heart failure and hemodialysis patients. We measured average pressure and average peak velocity of SFA with a pressure/Doppler flow sensor-tipped combination guide wire. We assessed FFR, hyperemic stenosis resistance (h-SR) and VFR before and after endovascular therapy. h-SR was defined as the ratio of ΔP (stenotic segment average pressure gradient) to hyperemic average peak velocity. Hyperemia was induced with intra-arterial 20mg papaverine infusion. Results: Significant alterations were observed after endovascular therapy in FFR (from 0.81±0.12 to 0.97±0.06, p<0.01), h-SR (from 0.56±0.44 to 0.09±0.12 mmHg•sec/cm, p<0.01) and VFR (from 1.73±0.31 to 1.91±0.41, p<0.05) in focal SFA stenosis. h-SR was more strongly correlated with % area stenosis measured by intravascular ultrasound than FFR (h-SR: r=0.741, FFR: r=-0.716, p<0.001 each) before endovascular therapy. VFR was not associated with % area stenosis (r=0.120, n.s.). The cut-off points with h-SR >0.36 mmHg•sec/cm and FFR <0.88 predicted over 75% area stenosis with area under curves of 0.883 and 0.828, respectively, by a receiver operating characteristic curve analysis. Conclusions: h-SR can indicate the stenotic severity in SFA focal lesion and may be a more better physiological index to determine indication for endovascular treatment than FFR. On the other hand, VFR was not feasible for assessment in SFA focal stenosis. [ABSTRACT FROM AUTHOR]

Introduction: In patients with critical limb ischemia, it is desirable to keep lower limb skin perfusion pressure (SPP) ≥40 mmHg. Two dimensional (2D)-perfusion angiography is an evolving technique for quantitative tissue perfusion analysis. However, 2D-perfusion angiography analysis for below the knee (BK) is not established. Hypothesis: We assessed the hypothesis that 2D-perfusion angiographical parameters of lower limb are related to SPP after endovascular treatment (EVT) for BK lesions. Methods: We enrolled 31 limbs (mean age 74.8 years, men 70%) which underwent EVT for BK lesions. Twenty two limbs were critical limb ischemia. Severe tissue loss subjects as Rutherford category 6 were excluded. We quantified indexed blood flow by using 2D-perfusion angiography. Region of interest was placed on the below the ankle in the 2D perfusion image, and then parameters were analyzed by the graph of time and density. Six parameters [arrival time, time to peak, wash-in rate, width, area under the curve and mean transit time] were acquired after EVT. Hyperemia was induced by intra-arterial 20mg papaverine infusion. Results: Dorsal and plantar SPP were significantly correlated with hyperemic arrival time (dorsal: r=-0.42, P=0.032; plantar: r=-0.42, P=0.034), hyperemic wash-in rate (dorsal: r=-0.42, P=0.031; plantar: r=-0.45 P=0.020), and hyperemic/baseline arrival time ratio (dorsal: r=-0.58, P=0.0020; plantar: r=-0.40 P=0.044) of lower ankle regions after EVT. However, only arrival time ratio was independently associated with dorsal SPP in multivariate analysis after EVT (P=0.048). A receiver operating characteristic curve showed arrival time ratio < 0.86 predicted to obtain SPP levels ≥40 mmHg after EVT with an area under curve of 0.77 (95% confidence interval, 0.56-0.98). Conclusions: Arrival time ratio was an independent predictor for SPP levels after EVT. Arrival time ratio < 0.86 of lower ankle regions may be essential to obtain the minimum levels of SPP for limb salvage after BK intervention. 2D-pefusion imaging in hyperemic condition can be feasible to predict limb tissue perfusion after EVT. [ABSTRACT FROM AUTHOR]