Aortic bifurcation reconstruction: use of the Memotherm self-expanding nitinol stent for stenoses and occlusions

Midterm outcomes of endovascular treatment with bare metal stents for Leriche syndrome patients

OBJECTIVES

This study was undertaken to evaluate the acute and midterm results of endovascular treatment with bare metal stents (BMS) for Leriche syndrome patients.

METHODS

Patients with Leriche syndrome treated with BMS from August 2008 to May 2017 were included in the study and followed up. The primary endpoints were primary restenosis-free survival rates at 1, 2 and 3 years. The secondary endpoints were secondary restenosis-free and freedom from target lesion revascularization survival rates at 1, 2 and 3 years; technical success rate; complication rate; procedure-related mortality rate; and clinical status improvement at follow-up.

RESULTS

Twenty patients were included and the follow-up duration was 34.7 ± 18.7 months (0-86 months). The 1-, 2- and 3-year primary restenosis-free survival rates were 94.4%, 88.1% and 73.5% and the secondary patency rates were 94.4%, 94.4% and 86.6%, respectively. The freedom from target lesion revascularization survival rates of patients at 1, 2 and 3 years were 94.4%, 88.1% and 79.3%, respectively. The aortoiliac lesions were successfully treated with BMS bilaterally in 17 patients (85.0%) and unilaterally in another 3 patients (15.0%). The complication rate was 10.0% and the procedure-related mortality rate was 0%. Mean ankle-brachial index increased significantly from 0.43 ± 0.20 before the procedure to 0.95 ± 0.21 after the procedure (P < 0.001), and to 1.00 ± 0.19 at the end of the follow-up (P < 0.001). Improvement in symptoms occurred in most patients soon after the endovascular procedure (95.0%) and at follow-up (88.2%).

CONCLUSIONS

Endovascular treatment with BMS is effective and safe for patients with Leriche syndrome according to 3-year follow-up results.

Comparison of results between kissing stent and aortic bifurcated bypass in aortoiliac occlusive disease

OBJECTIVE

Kissing stent (KS) technique has been used as an alternative to aortic bifurcated bypass surgery (ABBS) for aortoiliac occlusive disease (AIOD). We aimed to compare the results of ABBS and KS in AIOD.

METHODS

Medical records of patients treated with ABBS and KS between March 2011 and December 2016 in a single center were retrospectively analyzed. The patients' characteristics and clinical outcomes were evaluated.

RESULTS

Patients who underwent ABBS had a more common history of smoking (P = 0.04) and lower body mass index (P = 0.02). A significant difference was observed between the two groups in terms of the TransAtlantic Inter-Society Consensus II classification (P < 0.01). A significant difference was observed between the two groups of improvement in postoperative mean ankle-brachial indexes (ABI) (ABBS: 0.57 ± 0.24 vs KS: 0.41 ± 0.18, P = 0.01). A significant difference was observed between the combined treatments of the two groups (P < 0.01). Primary patency rates of the ABBS and KS groups at 1, 2, and 3 years were 90.1% and 100%, 82.6% and 90.6%, and 82.6% and 90.6%, respectively (P = 0.637). Primary assisted patency rates of the ABBS and KS groups at 1, 2, and 3 years were 90.1% and 100%, 82.6% and 95.7%, and 82.6% and 95.7%, respectively (P = 0.110). Secondary patency rates of the ABBS and KS groups at 1, 2, and 3 years were 93.8% and 100%, 93.8% and 95.7%, and 93.8% and 95.7%, respectively (P = 0.512).

CONCLUSION

ABBS in AIOD remains an important revascularization option whenever endovascular treatment is not feasible.

Long-term results of stenting of the aortic bifurcation

BACKGROUND

To evaluate the long-term results in a multicentric continuous series of narrowing lesions of the aortic bifurcation treated with a kissing stent.

METHODS

From January, 1st 1999 to the December, 31st 2001, all of the patients (n = 80) presenting with stenosis of the aortic bifurcation (n = 15) and/or the 2 common iliac arteries (n = 65), treated with a kissing stent, in 8 teaching hospitals were collected retrospectively. The risk factors were smoking (91%), dyslipidemia (60%), arterial hypertension (42%) and diabetes (27%). In 84% of cases, the indication for treatment was claudication. The lesions were stenotic < 70% (n = 76) and/or thrombotic (n = 18). The associated lesions were external iliac stenoses (n = 21), common femoral stenoses (n = 19), femoro-popliteal stenoses (n = 42), arteriopathy in the leg (n = 35). Follow-up was clinical examination and Doppler US scan.

RESULTS

The success rate of the technique was 89%. There were 4 cases (5.3%) of residual stenosis and 4 cases (5.3%) of dissection. The length of the lesions treated in the aorta and the iliac arteries was respectively 17.1 ± 7 and 17.3 ± 9 mm. The stents were all placed as kissing stents, and had a mean diameter and a mean length of 13.75 mm and 56 mm in the aorta and 9 mm and 48 mm in the iliac arteries, respectively. At 5 years, 19 patients had required repeat angioplasty in the treated area, and 13 had undergone open surgery. Primary and assisted primary patency at 5 years were 64.5% and 81.8%, respectively.

CONCLUSION

Long-term follow-up of endovascular treatment with kissing stents for stenosis of the aortic bifurcation shows that this technique gives good results, though it does not justify doing away with classical revascularisation surgery, in a population with major cardiovascular risk factors.

Histopathologic evaluation of a novel‐design nitinol stent: the Biflex stent

BACKGROUND

Optimalization and improvement in stent material, stent design and deployment may alleviate the problem of restenosis after stenting. The Biflex stent is a novel-design stent made of nitinol; the vascular response after deployment in rabbit iliac arteries was evaluated.

METHODS AND RESULTS

Normocholesterolemic New Zealand white rabbits (n = 8) were used. Iliac arteries were randomized to receive either a stainless steel control stent or a nitinol stent and rabbits were euthanized at 30 days after implantation. All animals survived and there were no adverse events. Vessels were harvested and prepared for histopathologic analysis and histomorphometry. Stents were well opposed to the vessel wall and thrombi were absent. The lumen area and the area within the internal elastic lamina were significantly larger in the nitinol stent group as opposed to the control group (3.8 +/- 0.1 vs 3.3 +/- 0.1 mm, p = 0.009 and 4.6 +/- 0.1 vs 4.1 +/- 0.2 mm, p = 0.03, respectively). There were no differences in injury score, neointimal area, medial area, area within the external elastic lamina and amount of inflammatory cells. Staining for alpha-smooth muscle cell actin and endothelium did not show any differences between the two groups as assessed semiquantitatively.

CONCLUSION

This nitinol stent with a novel design demonstrated acceptable biocompatibility in iliac arteries of normocholesterolemic rabbits with minimal foreign-body reaction and minimal neointimal formation.

Long-term results after placement of aortic bifurcation self-expanding stents: 10 year mortality, stent restenosis, and distal disease progression

PURPOSE

To retrospectively evaluate the 10 year follow-up results in patients who had "kissing" self-expanding stent aortic bifurcation reconstruction.

METHODS

Forty-three patients were treated with "kissing" self-expanding stents for aortoiliac occlusive disease. Early follow-up with clinical and ankle brachial pressure indices (ABPI) was performed at 3, 6, 12, and 24 months and with intra-arterial digital subtraction angiography at 12-24 months; clinical and angiographic follow-up was performed for symptom recurrence up to 10 years after treatment. Retrospective record review was performed to assess mortality, clinical patency, angiographic patency, and secondary assisted patency of both stents and downstream peripheral vessels at 5 and 10 years follow-up.

RESULTS

The 2 year primary angiographic and secondary assisted stent patencies were 89% and 93%, respectively. At 10 years follow-up in 40 patients the mortality was 38% (due to myocardial infarction, stroke, chronic renal failure, malignancy, and liver failure). At 5 and 10 years follow-up the primary clinical stent patency was 82% and 68%, and the secondary assisted stent patency 93% and 86%, respectively. At 5 and 10 years, the distal vessel patency was 86% and 72%, and the secondary assisted distal vessel patency treated by surgical or endovascular techniques was 94% and 88%, respectively. At 10 years there was no limb loss.

CONCLUSION

The long-term (10 year) results of aortic bifurcation arterial self-expanding stent placement in patients with arterial occlusive disease show a 10 year primary stent patency rate of 68% but a secondary assisted patency rate of 86%. In addition there is a high overall mortality due to other cardiovascular causes and the rate of distal disease progression and loss of patency is similar to the loss of stent patency rate.

Aortoiliac Kissing Stents:Long-term Results and Analysis of Risk Factors Affecting Patency

PURPOSE

To present the early and long-term results of aortoiliac kissing stents implantation and evaluate the risk factors affecting patency.

METHODS

The data were retrospectively reviewed on 68 patients (64 men; mean age 55+/-11, range 32-77) who underwent kissing stents implantation during a 12-year period. The majority of patients (64, 94%) had claudication; 4 patients had rest pain. All were smokers. There were bilateral or unilateral stenoses in 42 (62%) patients, and unilateral occlusion and contralateral stenosis in 26 (38%). Lesions were treated with simultaneous implantation of self-expanding (n=52) or balloon-expandable (n=16) stents. After the procedure, patency was determined with Doppler ultrasonography or angiography at 1, 3, 6, and 12 months and annually thereafter. Primary, assisted primary, and secondary patency rates were calculated with Kaplan-Meier analysis on an intention-to-treat basis, and risk factors affecting the patency rates were determined with the Cox regression analysis.

RESULTS

All procedures were technically and clinically successful. Complications occurred in 12%, but none required surgery. The follow-up period was 35+/-31 months. Primary, assisted primary, and secondary patency rates, respectively, were 76%, 90%, and 94% at 1 year; 63%, 86%, and 92% at 3 years; and 63%, 64%, and 81% at 5 years. In multivariate analysis, age <50 years and presence of iliac occlusion were identified as risk factors for reduced primary and assisted primary patency; a crossed configuration of kissing stents was identified as a risk factor for reduced primary patency.

CONCLUSION

Implantation of kissing stents is a safe and effective alternative in the treatment of aortoiliac obstructions. However, overall primary and assisted primary patency rates are inferior to those reported for surgery. Long-term patency comparable to surgery may be obtained in patients >50 years and in those without an iliac occlusion, particularly if a favorable stent configuration is achieved.

Traitement endovasculaire percutané des lésions oblitérantes du carrefour aorto-iliaque : résultats chez 28 patients

OBJECTIVE

We conducted a retrospective analysis of short- and mid-term results of endoluminal treatment of obstruction lesions involving the terminal aorta and the initial portions of the iliac arteries in 28 patients.

PATIENTS AND METHODS

Twenty-eight patients (9 women, 19 men, mean age 57.5 Years) presented 52 obstructive atheromatous lesions of the aorto-iliac bifurcation. The lesions were divided into three topographic groups (9 unilateral lesions, 19 bilateral ostial lesions, 5 widespread lesions of the terminal aorta) and identified as simple (44%) or complex (56%, more than 2 cm in length and/or calcified and/or eccentric).

RESULTS

Technical success was achieved in 93% of the cases with only one hematoma of the puncture site. Primary and secondary patencies were 78.9% and 93% after a mean follow-up of 50 Months (range 4-85). Clinical outcome remained good at this term for all cases of technical success but complete resolution of the symptoms was more frequent when a stent was used (84%) than for simple balloon dilatation (49%).

CONCLUSION

Percutaneous treatment of obstructive lesions of the aorto-iliac bifurcation may be proposed when possible as a first-line treatment.

Kissing stents for treatment of complex aortoiliac disease

OBJECTIVES

to determine medium term technical and clinical success of kissing stents for aortoiliac occlusive disease.

DESIGN

retrospective study.

SUBJECTS

twenty-five patients presenting with intermittent claudication (IC) or critical limb ischaemia (CLI) due to aortoiliac disease (41 complex stenoses, 8 occlusions).

METHODS

balloon- or self-expanding kissing stents, with or without predilatation depending upon the nature of the disease, were inserted via bilateral retrograde femoral artery punctures. Clinical examination, ABPI, exercise testing and duplex ultrasound were performed at 1, 3, 6, and 12 months, and then annually.

RESULTS

technical success was achieved in 86% segments. All patients with CLI improved and 6 of 7 ulcerated limbs showed complete healing. During follow-up, 7 patients died and two patients required major amputation at 7 and 8 months. The primary assisted patency rate was 94, 91 and 65% at 6, 12, and 24 months, respectively.

CONCLUSIONS

despite acceptable short-term technical and clinical success, as the medium term patency rates are clearly inferior to those of bypass surgery, the kissing stent technique should be reserved for high risk patients with a limited life expectancy.

Percutaneous reconstruction of the aortoiliac bifurcation with the "kissing stents" technique: long-term follow-up in 106 patients

PURPOSE

To evaluate the long-term results using the kissing stents technique for treatment of occlusive disease involving the aortoiliac bifurcation.

METHODS

One hundred six patients (97 men; mean age 52.5 +/- 10.2 years, range 33-78) were treated with the kissing stents technique for bilateral aortoiliac stenosis (55, 51.9%), unilateral occlusion of the common iliac artery (CIA) with contralateral stenosis (47, 44.3%), and bilateral CIA occlusion (4, 3.8%). Clinical examination and duplex scans were performed prior to discharge and at 1, 6, and 12 months, followed by yearly examinations thereafter.

RESULTS

Bilateral stent implantation was successful in all patients. No major procedure-related complications were observed. Self-expanding stents were deployed in 62 (58.5%) patients and balloon-expandable devices in 44 (41.5%). Fifteen (7.1%) hematomas were observed at the 212 access sites. Mean follow-up was 30.1 +/- 11.1 months (range 12-137). Duplex imaging diagnosed significant (>50%) restenosis in 15 (14.8%) of 101 patients and reocclusion in 4 (4%); 17 (89.5%) of these patients had recurrent symptoms and all were retreated (endovascular procedure in 18 and an aortobifemoral bypass in 1). Primary and secondary cumulative patency rates at 36 months were 79.4% and 97.7%, respectively. Balloon-expandable stents had a nonsignificantly higher patency rate compared to self-expanding stents.

CONCLUSIONS

Based on our experience, aortoiliac endovascular reconstruction with the kissing stents technique is a safe and effective procedure, representing an alternative to conventional surgery in selected patients.

Multicenter study of the feasibility and safety of using the memotherm carotid arterial stent for extracranial carotid artery stenosis

OBJECT

Carotid artery (CA) angioplasty with stent placement has been proposed as an alternative technique for revascularization in cases of CA stenosis. In this report the authors review the results of a multicenter Phase I study in which they evaluated the safety and feasibility of using a new self-expanding nitinol stent, the Bard Memotherm, to treat CA stenosis.

METHODS

Enrollment was limited to patients in whom there was either 50% or greater symptomatic or 70% or greater asymptomatic stenosis of the internal CA. The primary endpoint was a technically successful implantation procedure (delivery of the stent to the target site and retrieval of the delivery device), resulting in less than 30% residual stenosis demonstrated on immediate postprocedure (control) angiograms, and no incidence of mortality, ipsilateral stroke, Q-wave myocardial infarction, or other major cardiovascular events immediately after or within 30 days following the procedure. Stent placement was attempted for 73 lesions in 71 patients (mean age 71.3 +/- 8.5 years), 43 (61%) of whom were men. The mean degree of stenosis was 82.6 +/- 9%. The stenosis was symptomatic in 27 (37%) and asymptomatic in 46 (63%) of 73 lesions. In four procedures the stent could not be delivered or released. The mean residual stenosis observed on angiograms was 3.8 +/- 6.9% in the 69 lesions treated with the Bard Memotherm stent; residual stenosis was greater than 30% in one of the 69 procedures. The primary endpoint was achieved in 65 (89%) of the 73 procedures. One patient experienced a major ischemic stroke and another patient died of intracerebral hemorrhage. The overall 1-month stroke rate was 2.7% for 73 attempted procedures. One patient died of pneumonia and acute respiratory distress syndrome, which occurred 3 weeks after the stent procedure and was unrelated to the procedure.

CONCLUSIONS

The Memotherm stent can be used to treat patients with CA stenosis and is associated with a low peri-procedure complication rate. Long-term follow-up studies are underway to determine the impact of stent placement on the risk of ipsilateral ischemic events.