Three-Year Efficacy and Safety of the Misago Peripheral Stent for Superficial Femoral Artery Disease: Final Results from the OSPREY Trial

PURPOSE

This study evaluated the long-term outcomes of the Misago peripheral stent trial (Terumo) for atherosclerotic lesions in the superficial femoral artery (SFA) in patients with claudication.

MATERIALS AND METHODS

This was a prospective multicenter, single-arm, clinical trial of primary stent placement for de novo cases of SFA disease conducted in the United States and Asia. The primary endpoint was freedom from clinically driven target lesion revascularization (CD-TLR) at 36 months. Secondary outcomes were ankle-brachial index (ABI), Rutherford score, Walking Impairment Questionnaire (WIQ), a quality of life survey, and rate of device fracture.

RESULTS

A total of 276 patients (64.4% male; mean age, 69.3 ± 10.1 years) were enrolled. Freedom from CD-TLR was 78.5% (95% confidence interval [CI], 73.0%-83.0%) at 24 months and 75.4% (95% CI, 69.6%-80.2%) at 36 months. Baseline ABI was 0.7 ± 0.1 and 0.98 ± 0.20 (P < .001) at 30 days after the procedure. Baseline Rutherford score was 3.6 ± 0.6 and 1.6 ± 1.0 30 at 30 days after the procedure (P < .001). Mean (and changed) ABI and Rutherford score at 36 months compared to day 30 after the procedure were, respectively, 0.91 (-0.1 ± 0.2) and 1.5 (-0.2 ± 1.1). WIQ score at baseline was 21.49 ± 26.30 and 50.51 ± 38.49 at 30 days after the procedure ( P < .001). The mean WIQ score at 2 years was 46.65 ± 37.31 (P = .12). Stent fracture rate at 36 months was 2.0% (4 of 202 patients).

CONCLUSIONS

OSPREY (Occlusive-Stenotic Peripheral Artery Revascularization Study) 36-month data demonstrated persistent freedom from CD-TLR and sustained improvement in ABI and Rutherford score with primary stent placement for SFA lesions.

Superficial femoral artery stenting via radial access using R2P® Misago® stents: First-in-human report of the new R2P® system

A 73-year-old male with left critical limb ischemia was scheduled to undergo below-the-knee amputation. Prior to the amputation, he was referred to our institute for endovascular treatment. We inserted the new 7-Fr 150-cm-long guiding catheter, SlenGuide^®, into the external iliac artery from the right radial artery with the 7-Fr Glidesheath Slender^®. We implanted two R2P^® Misago^® stents with rapid-exchange, 200-cm-long shaft system in the stenosis of the left superficial femoral artery. This new stent system involves rapid-exchange and a long shaft system; furthermore, it is useful in transradial stenting in the superficial femoral artery.

Retrospective Multicenter Comparison of S.M.A.R.T. CONTROL and MISAGO Stents in Treatment of Femoropopliteal Lesions

PURPOSE

To compare primary patency between MISAGO (Terumo Corporation, Tokyo, Japan) and S.M.A.R.T. CONTROL (Cordis Corporation, Miami Lakes, Florida), second-generation and first-generation nitinol stents, in femoropopliteal lesions.

MATERIALS AND METHODS

This multicenter, retrospective study included 240 cases with MISAGO stent implantation and 1,265 cases with S.M.A.R.T. stent implantation. The S.M.A.R.T. group had more Trans-Atlantic Inter-Society of Consensus (TASC) II class C/D lesions (53% vs 41%, P = .001) and smaller reference vessel diameter (RVD) (5.3 mm ± 0.9 vs 5.5 mm ± 0.9, P < .001).

RESULTS

Kaplan-Meier estimates of 2-year primary patency after S.M.A.R.T. and MISAGO stent implantation were 67% and 55% (P = .007). Interaction analysis revealed that TASC II classification and RVD had a significant influence on the association of MISAGO versus S.M.A.R.T. stents with the outcome. The study population was stratified according to TASC II classification and RVD, and MISAGO and S.M.A.R.T. stents were compared after propensity score matching. There was no significant difference in 2-year patency between the 2 stents in the subgroup with TASC II class A/B and RVD ≥ 5 mm (S.M.A.R.T. 82% ± 4 vs MISAGO 74% ± 5, P = .480). MISAGO stents had lower primary patency than S.M.A.R.T. stents in cases with TASC II class C/D or RVD < 5 mm (S.M.A.R.T. 62% ± 6 vs MISAGO 25% ± 6, P = .015).

CONCLUSIONS

S.M.A.R.T. and MISAGO stents had similar patency in simple lesions, but MISAGO stents had lower patency than S.M.A.R.T. stents in more complex lesions.

Direct stent puncture technique for intraluminal stent recanalization in the superficial femoral and popliteal arteries in-stent occlusion: outcomes from a prospective clinical analysis of diabetics with critical limb ischemia

PURPOSE

To evaluate the efficacy and safety of "Direct Stent Puncture" technique for intraluminal stent recanalization in the femoro-popliteal segments.

METHODS AND MATERIALS

A cohort of diabetics who had symptomatic in-stent occlusion of the superficial femoral or popliteal arteries underwent endovascular recanalization. After antegrade failure, direct stent puncture technique was performed. The primary end-point was to efficacy assessment, intended as technical success and clinical improvement. The secondary end-point was safety assessment, intended as free of complication rate.

RESULTS

Fifty-four patients (37 men; 73.6±8.5 years) underwent direct stent puncture technique, after several unsuccessful antegrade attempts to cross the occluded stent. Technical success for intraluminal stent recanalization was achieved in 53/54 (98.2%) of cases and failed in 1/54 (1.8%). Clinical improvement was obtained in 51/54 (94.4%) of cases, with regression of the clinical symptoms and improvement of the TcPO2, from 3±18 mmHg to 43±11 mmHg after 15 days (p<0.001). Free of complications rate was 92.5%. In 2/54 (3.7%) of cases distal embolization occurred, in 1/54 (1.9%) case a sudden vessel thrombosis was diagnosed after 12 hours and in 1/54 (1.9%) case hematoma at the stent puncture site was observed.

CONCLUSIONS

Direct Stent Puncture technique is an efficacy and safety option for intraluminal stent recanalization in the femoro-popliteal segment in-stent occlusion.

Evaluation of the 4-French Pulsar-18 Self-expanding Nitinol Stent in Long Femoropopliteal Lesions

PURPOSE

To evaluate the patency and the freedom of target lesion revascularization of the 4-French Pulsar-18 self-expandable (SE) nitinol stent for the treatment of long femoropopliteal occlusive disease in a two-center, prospective, all-comers registry with a follow-up period of 12 months.

METHODS

This registry enrolled 36 patients with symptomatic femoropopliteal long lesions for recanalization and implantation of the 4-French Pulsar-18 SE nitinol stent. Routine follow-up examination including duplex ultrasound was performed after 6 and 12 months. Primary patency was defined as no binary restenosis on duplex ultrasound (Peak systolic velocitiy ration (PSVR) <2.5) and no target lesion revascularization was performed within 12 months’ follow-up. No drug-eluting devices were allowed in this registry.

RESULTS

Average lesion length of the femoropopliteal segment was 182.3 ± 51.8 mm. Mean stent implantation length was 181.5 ± 35.4 mm. Total occlusion was present in 46 of the 48 (95.8%) treated lesions. Involvement of popliteal segment I–III was present in 3 (6.3%) lesions. The primary patency after 6 and 12 months was 87.5% and 85.4%, respectively. The clinically driven overall freedom from target lesion revascularization (fTLR) was 89.6% after 6 months and 87.5% after 12 months. ABI, pain-free walking distance and Rutherford category, all improved significantly (P < 0.001) after 6 and 12 months. The primary patency rate in patients with diabetes (P = 0.18) and renal insufficiency (P = 0.3) was not significantly lower as compared to the overall primary patency.

CONCLUSIONS

In this two-center, all-comers registry, the use of the Pulsar-18 SE nitinol stent for endovascular intervention of femoropopliteal disease with a mean lesion length of 182.3 ± 51.8 mm showed promising primary patency and fTLR rates after 6 and 12 months. Diabetes and renal insufficiency had no negative impact on the patency rate.

An instant rare complication: a fractured metallic pyloric stent

Metallic pyloric stenting (also termed as metallic enteral stenting) performed endoscopically, stands as first-line treatment for malignant gastric outlet obstruction. With reported evidence, these self-expandable metallic stents (SEMS) re-enable oral food intake, preventing patients having to face invasive techniques such as surgical gastroenterostomy. We report a patient having received a covered pyloric SEMS insertion following a tumour growth causing stenosis in the gastric antropyloric region. After 3 weeks, the patient presented with a fracture of the pyloric SEMS, a rare complication, resulting in a second pyloric SEMS insertion.

Comparison of second-generation stents for application in the superficial femoral artery: an in vitro evaluation focusing on stent design

PURPOSE

To examine and compare in an ex vivo study different nitinol stent designs intended for the superficial femoral artery (SFA) with regard to the appearance of fracture.

METHODS

Seven different 8-×40-mm nitinol stents were evaluated (Misago, Absolute, Smart, Luminexx, Sentinol, Lifestent NT, and Sinus-Superflex). Finite element analysis (FEA) was used for digitalized stent design comparison; the strain during stent movement was calculated for bending, compression, and torsion. Additional mechanical fatigue tests for bending (70°), compression (40%), and torsion (twisted counterclockwise by 180°) were performed up to 650,000 cycles or until a fracture was observed.

RESULTS

The FEA bending test showed that only the Misago, LifeStent, and Absolute stents presented no zones of high strain; in the torsion test, the Smart stent also had no zones of high strain. Macroscopic evaluation after mechanical bending indicated that the LifeStent performed the best (no stent fracture after 650,000 cycles). Misago and Absolute stents showed fractures at 536,000 cycles and 456,667 cycles, respectively (range 320,000-650,000 cycles). After compression and torsion testing, Misago showed no stent fracture after 650,000 cycles. The worst performing stent was Luminexx during all test cycles.

CONCLUSION

The 7 SFA stents showed differences in the incidence of high strain zones, which indicates a potential for stent fracture, as demonstrated by the mechanical fatigue tests. Differences in stent design might play a major role in the appearance of stent strut fracture related to restenosis and reocclusion.