Placement of balloon-expandable intraluminal stents in iliac arteries: first 171 procedures

[Vascularsurgical Long-term Outcome - Comparison of Orthotopic and Extraanatomic Reconstructions in Unilateral Occlusions of Iliac Artery over 10 Years]

In PAOD, several vascular regions are usually affected, the pelvic axis in 35% of cases. Interventional-radiological/endovascular or hybrid interventions have been established for recanalization, so that bypass procedures are increasingly taking a back seat, but are not losing their importance.To study unilateral iliac artery occlusions (inclusion criterion) that were repaired either by implantation of an orthotopic or extraanatomic bypass (oBP/eaBP).Over a defined period of time, the rate of open vessel, complications (frequency, type, severity) to characterize morbidity and mortality as well as the extent of clinical improvement after BP implantation were analyzed in a clinical-systematic, single-center observational study (for vascular surgical quality assurance and contribution to vascular medical-clinical health care research). The study method was not explicitly based on the STROBE criteria, but essentially corresponds to them.Over 10 years, 122 PAOD patients (50% in stage IIb-stage III and IV equally distributed; mean age: 63 [range, 44-87] years; majority ASA III) were included with the same number of reconstructions: 71 patients received an eaBP ("crossover"), 51 patients an iliacofemoral (orthotopic - oBP) bypass (neither significant difference regarding frequency nor number of risk factors per patient).The oBP is not superior to eaBP with regard to the analysis parameters of openness, complication rate and mortality. Furthermore, extraanatomic revascularization does not have to be reserved for polymorbid patients only.

Acute ischemia secondary to popliteal artery stent fracture and embolization

Femoropopliteal disease comprises more than one half of lesions in peripheral vascular disease. The treatment modalities for stenosis or occlusion of this anatomic region include femoropopliteal bypass and percutaneous transluminal angioplasty with or without stenting. Our patient developed acute leg ischemia 3 years after stenting, secondary to stent fracture, with distal embolization of stent fragments. Using mechanical thromboembolectomy and superficial femoral artery to below-the-knee popliteal in situ saphenous vein bypass, we were able to restore perfusion to the limb and retrieve fragments of the fractured stent.

Stent Grafting for Aortoiliac Occlusive Disease: Review of the VBX FLEX Study

Endovascular treatment has become an accepted method in the treatment of aortoiliac occlusive disease. Bare metal stents have been used in the treatment of aortoiliac disease since the early 1990s. More recently, the use of covered stent grafts in the aortoiliac segment has shown clinical benefit in terms of patency, freedom from reintervention and quality of life. The VBX FLEX study evaluated the safety and efficacy of the Gore VBX stent graft for use in the aortoiliac segment. The early and mid-term data on the Gore VBX stent graft have shown it to be a safe device for use in the treatment of aortoiliac occlusive disease. This review examines the use of stents in aortoiliac occlusive disease with specific focus on the VBX FLEX Study.

Descending thoracic aorta to bilateral femoral artery bypass and thoracic endovascular aortic repair in the management of atypical aortoiliac occlusive disease

Despite recent advancements in endovascular technology and the proven durability of open surgery, extensive thoracoabdominal aortoiliac occlusive disease (AIOD) remains challenging to treat. In the present report, we have described the case of a 58-year-old woman with AIOD and multiple medical comorbidities. She successfully underwent a novel intraoperative transesophageal echocardiography-guided combined treatment with concurrent descending thoracic aorta to bilateral femoral artery bypass and thoracic endovascular aortic repair. We have shown that this approach, which combines descending thoracic aorta to bilateral femoral artery bypass with thoracic endovascular aortic repair, is an effective treatment alternative for future cases of complex AIOD.

Initial Experience with the Cragg Endopro System 1 for Intraluminal Treatment of Peripheral Vascular Disease

Purpose:

To evaluate the safety and efficacy of a new covered stent, the Cragg Endopro System 1, for intraluminal treatment of peripheral vascular disease in the iliac and femoropopliteal arteries.

Methods:

Forty symptomatic patients with predominantly lengthy stenotic (24) or occlusive (13) lesions or aneurysms (3) in the iliac (19), femoral (19), or popliteal (2) arteries were treated percutaneously with balloon angioplasty followed by implantation of the self-expanding nitinol Cragg stent covered by a woven polyester fabric coated with low-molecular-weight heparin. The mean length of femoropopliteal lesions was 13.0 ± 1.8 cm, as compared to 6.7 ± 0.8 cm (p < 0.01) for iliac lesions. Mean percent stenosis was 89% ± 2% with no significant difference between the arterial segments.

Results:

With a total of 52 covered stents implanted, technical success was achieved in 98% (39/40 patients). One tortuous femoral artery aneurysm was not satisfactorily excluded to prevent leakage. Clinical success was seen in all patients with demonstrable improvements in the claudication stage and the ankle-brachial index from a mean 0.54 to 0.92. Three local complications (one hematoma, two false aneurysms) required surgical repair. One distal embolism, one acute thrombosis, and three subacute thromboses were encountered and successfully treated by thrombolysis and/or surgery. One patient with two iliac stents developed contralateral common iliac artery occlusion from a stent partially obstructing the aorta; placement of a covered stent in the blocked artery re-established normal flow. Over an 8-month follow-up with arteriographic re-examination, all iliac stents remained patent. At the femoropopliteal level, two stents were occluded at 4 months; one was successfully dilated, but the other required surgical bypass grafting. A third patient developed a stenotic lesion proximal to the stent; dilation restored adequate inflow to the stent.

Conclusions:

The Cragg Endopro System 1 appears to be effective as an “internal bypass” for iliac and femoropopliteal occlusive disease. More complications and restenosis were seen in femoropopliteal implantations; however, a change in postoperative medication may improve these results. Long-term results will determine if the Cragg Endopro System 1 can achieve a patency equal to conventional bypass grafting.

Strecker Stents in the Femoropopliteal Arteries: Value of Duplex Ultrasonography in Restenosis Assessment

Purpose:

Experience with Strecker stent implantation in the femoropopliteal arteries has been described; however, few of the reports were prospective studies, and none routinely used site-specific assessment methods for follow-up evaluation of stent patency. The purpose of this study was to evaluate 1-year Strecker stent patency using duplex ultrasound imaging to obtain a more precise delineation of stent restenosis than is possible with other noninvasive assessment modalities.

Methods:

A prospective study involved 52 patients with 57 sites treated by angioplasty and Strecker stent deployment in the femoropopliteal arteries. Assessment included clinical evaluation; ankle-brachial index (ABI) measurements at rest and after exercise; and duplex ultrasound imaging preprocedurally and at 3 and 12 months after the intervention.

Results:

All 74 stents were deployed successfully in the 35 occluded arteries and 22 stenotic lesions. Acute reocclusion occurred in 6 (10%). At 3 months, primary patency was 81% and secondary patency 84%. Mean (± SD) ABIs increased from 0.64 ± 0.15 at rest and 0.32 ± 0.17 after exercise to 0.89 ± 0.14 and 0.68 ± 0.23, respectively (p < 0.0001). At 12 months, primary patency was 79%, and secondary patency was 82%. Mean ABIs were 0.82 ± 0.15 at rest and 0.52 ± 0.22 after exercise at 12 months (p < 0.0001 compared with preprocedural ABIs). Analysis of the length of lesion treated showed better results with shorter diseased segments, but this was not statistically significant (p > 0.05). Better outcomes were also obtained when one stent was used rather than two stents at 12 months (p = 0.15), but there was no difference at 3 months (p = 0.3). Thirty-four percent of the stented segments progressed from < 20% stenosis at 3 months to > 50% stenosis at 12 months. Overall, 19 (43%) of 44 segments progressed from < 50% stenosis at 3 months to a > 50% stenosis at 12 months. Restenosis seen at 3 months generally was in the native artery just proximal or distal to the stent, but at 12 months, restenosis was mainly inside the stent.

Conclusions:

Strecker stents at 1-year demonstrated satisfactory patency in the femoropopliteal arteries when deployed for angioplasty salvage or recurrent disease. The 3- and 12-month evaluations obtained with duplex ultrasound provided site-specific hemodynamic data for stent assessment. Resting ankle pressures were a poor index of restenosis.

Carotid and Vertebral Stenting: Preliminary Report

We report our initial experience of carotid and vertebral stenting. Three haemodynamically significant extra-cranial lesions (% diameter stenosis >70) in 3 clinically symptomatic patients were treated by stenting between March 1996 and September 1996.

Two lesions of the internal carotid arteries were ostial and in one case a subtotal stenosis and ostial lesion of the vertebral artery were observed.

All lesions looked more widely and smoothly dilated by stenting than by ordinary standard balloon angioplasty.

Management of Atherosclerotic Aortoiliac Occlusive Disease

Development of aortoiliac occlusive disease (AIOD) is associated with classic risk factors for atherosclerotic disease such as hyperlipidemia, hypertension, diabetes, or smoking. Risk factor modification, smoking cessation, and prevention of cardiovascular events remain the cornerstones of AIOD management. Symptom improvement and limb loss prevention are considered secondary goals of therapy. Continuous technological advances, new devices, as well as new revascularization techniques are constantly changing the landscape of AIOD management. Surgical interventions, which were considered a gold standard therapy for nearly 50 years, currently give way to newer and less invasive endovascular techniques.

Peripheral arterial disease of the lower extremities

Persons with peripheral arterial disease (PAD) are at increased risk for all-cause mortality, cardiovascular mortality, and mortality from coronary artery disease. Smoking should be stopped and hypertension, dyslipidemia, diabetes mellitus, and hypothyroidism treated. Statins reduce the incidence of intermittent claudication and improve exercise duration until the onset of intermittent claudication in persons with PAD and hypercholesterolemia. The serum low-density lipoprotein cholesterol should be reduced to < 70 mg/dl. Antiplatelet drugs such as aspirin or clopidogrel, angiotensin-converting enzyme inhibitors, and statins should be given to persons with PAD. β-Blockers should be given if coronary artery disease is present. Cilostazol improves exercise time until intermittent claudication. Exercise rehabilitation programs should be used. Revascularization should be performed if indicated.

Peripheral arterial disease in women

Peripheral arterial disease (PAD) is chronic arterial occlusive disease of the lower extremities caused by atherosclerosis whose prevalence increases with age. Only one-half of women with PAD are symptomatic. Symptomatic and asymptomatic women with PAD are at increased risk for all-cause mortality, cardiovascular mortality, and mortality from coronary artery disease. Modifiable risk factors that predispose women to PAD include active cigarette smoking, passive smoking, diabetes mellitus, hypertension, dyslipidemia, increased plasma homocysteine levels and hypothyroidism. With regard to management, women who smoke should be encouraged to quit and referred to a smoking cessation program. Hypertension, diabetes mellitus, dyslipidemia, and hypothyroidism require treatment. Statins reduce the incidence of intermittent claudication and improve exercise duration until the onset of intermittent claudication in women with PAD and hypercholesterolemia. Anti-platelet drugs such as aspirin or especially clopidogrel, angiotensin-converting enzyme inhibitors and statins should be given to all women with PAD. Beta blockers are recommended if coronary artery disease is present. Exercise rehabilitation programs and cilostazol increase exercise time until intermittent claudication develops. Chelation therapy should be avoided as it is ineffective. Indications for lower extremity percutaneous transluminal angioplasty or bypass surgery in women are (1) incapacitating claudication interfering with work or lifestyle; and (2) limb salvage in women with limb-threatening ischemia as manifested by rest pain, non-healing ulcers, and/or infection or gangrene. Future research includes investigation of mechanisms underlying why women have a higher risk of graft failure and major amputation.

Novel thrombo-resistant coating based on iron-polysaccharide complex multilayers

The biocompatibility of iron-polysaccharide complexes has been well-documented. Herein, a stable thrombo-resistant coating was fabricated by consecutive adsorption of Fe (III) and polysaccharides including heparin (Hep) and dextran sulfate (DS) onto various surface by layer-by-layer self-assembly technique via both electrostatic interaction and chemical complexation process. The absorbance at 350 nm increased linearly with the number of Fe3+/Hep multilayer, indicating the formation of multilayer structure and the uniform coating. Compared with (Fe3+/Hep)10, the (Fe3+/DS/Fe3+/Hep)5 coating was more hydrophilic and stable due to the incorporation of DS. The activated partial thromboplastin time (APTT) and platelet adhesion assays showed that both (Fe3+/Hep)10 and (Fe3+/DS/Fe3+/Hep)5 coated surfaces were anticoagulant. The complexing with ferric ions did not compromise the catalytic capacity of heparin to promote antithrombin(III)-mediated thrombin inactivation. Chromogenic assays for heparin activity proved definitively that the inhibition of locally produced thrombin was contributed to the thromboresistance of the surface-bound heparin. The surface with Hep or DS as the outmost layer showed stronger anticoagulant activity than Fe3+, indicating that the outermost layer of the coating played a key role in anticoagulant activity. The utilization of dextran sulfate/heparin surfaces was more advantageous than merely the heparin surface for improving blood-contacting medical devices for long-term usage.

Endovascular treatment of atherosclerosis at the aortoiliac bifurcation with kissing stents or distal aortic stents: a temporary solution or durable improvement?

To evaluate medium-term technical and clinical success after endovascular treatment of stenosis or occlusion at the aortoiliac bifurcation with a distal aortic stent or kissing stents. Between 1995 and 2004, 25 patients were included in the study. Nine patients were treated with an aortic stent, and 16 patients were treated with kissing stents. Clinical and radiologic findings were retrospectively reviewed, and statistical analysis was performed. In all cases, the procedure was technically successful. Hemodynamic success was observed in 22 patients (88%), and clinical success was observed in 23 patients (92%). After a median follow-up of 21 months, 8 patients developed a restenosis (n = 6) or occlusion (n = 2). Two patients with restenosis were treated successfully with aortic bifurcation grafts, and 4 patients underwent endovascular reintervention. No risk factors for restenosis were identified. Primary patency was 87% after 1 year and 65% after 2 years. Secondary patency was 90% after 1 year and 72% after 2 years. At the last outpatient control, 22 patients (88%) were free of symptoms. Endovascular treatment of symptomatic aortoiliac atherosclerosis at the aortoiliac bifurcation by means of a distal aortic stent or kissing stents can be used successfully with durable improvement in the majority of patients. We recommend it as the initial treatment modality.

Stabilized hemocompatible coating of nitinol devices based on photo-cross-linked alginate/heparin multilayer

A novel stabilized hemocompatible multicomponent coating was engineered by consecutive alternating adsorption of two polysaccharides, alginate (Alg) and heparin (Hep), onto a Nitinol surface via electrostatic interaction in combination with photoreaction in situ. For this purpose, a photosensitive cross-linker, p-diazonium diphenyl amine polymer (PA), was used as an interlayer between alginate and heparin. The optical intensity of UV/vis spectra increased linearly with the number of layers, indicating the buildup of a multilayer structure and uniform coating. Photo-cross-linking resulted in higher stability without compromising its catalytic capacity to promote antithrombin III (ATIII)-mediated thrombin inactivation. Chromogenic assays for heparin activity proved definitively that anticoagulation activity really comes from surface-bound heparin in multilayer film, not from solution-phase free heparin that has leaked from multilayer film. The activated partial thromboplastin time (aPTT) assay showed that both (PA/Hep)8- and (PA/Alg/PA/Hep)4-coated Nitinol were less thrombogenic than the uncoated one. Yet, the latter was found to be more stable under a continuous shaken wash. In addition, (PA/Alg/PA/Hep)4 film exhibited lower surface roughness and higher hydrophilicity than (PA/Hep)8. As a result, hemolysis of (PA/Alg/PA/Hep)4 (0.34 +/- 0.064%) was lower than (PA/Hep)8 (0.52 +/- 0.241%). The naked Nitinol and (PA/Hep)8-coated Nitinol showed relatively strong platelet adhesion. On the contrary, no sign of any cellular matter was seen on the (PA/Alg/PA/Hep)4 surface. It is believed that the phenomenon of interlayer diffusion resulted in blended structures, hence, the enhanced wettability and antifouling properties after the incorporation of alginate layers. It is likely that the cooperative effect of alginate and heparin led to the excellent blood compatibility of the (PA/Alg/PA/Hep)4 coating. To simplify, there is greater advantage in utilizing cross-linked alginate/heparin surfaces rather than merely the heparin surface for improving blood- and tissue-compatible devices.

Peripheral arterial disease in the elderly

Smoking should be stopped and hypertension, diabetes mellitus, dyslipidemia, and hypothyroidism treated in elderly patients with peripheral arterial disease (PAD) of the lower extremities. Statins reduce the incidence of intermittent claudication and improve exercise duration until the onset of intermittent claudication in patients with PAD and hypercholesterolemia. Antiplatelet drugs such as aspirin or clopidogrel, especially clopidogrel, angiotensin-converting enzyme inhibitors, and statins should be given to all elderly patients with PAD without contraindications to these drugs. Beta blockers should be given if coronary artery disease is present. Exercise rehabilitation programs and cilostazol increase exercise time until intermittent claudication develops. Chelation therapy should be avoided. Indications for lower extremity percutaneous transluminal angioplasty or bypass surgery are (1) incapacitating claudication in patients interfering with work or lifestyle; (2) limb salvage in patients with limb-threatening ischemia as manifested by rest pain, nonhealing ulcers, and/or infection or gangrene; and (3) vasculogenic impotence.

Management of peripheral arterial disease of the lower extremities

Smoking should be stopped and hypertension, diabetes mellitus, dyslipidemia, and hypothyroidism treated in patients with peripheral arterial disease (PAD) of the lower extremities. Statins decrease the incidence of intermittent claudication and improve exercise duration until the onset of intermittent claudication in persons with PAD and hypercholesterolemia. Antiplatelet drugs such as aspirin or clopidogrel, especially clopidogrel, angiotensin-converting enzyme inhibitors, and statins should be given to all persons with PAD. Beta blockers should be given if coronary artery disease is present. Exercise rehabilitation programs and cilostazol increase exercise time until intermittent claudication develops. Chelation therapy should be avoided. Indications for lower extremity percutaneous transluminal angioplasty or bypass surgery are (1) incapacitating claudication in persons interfering with work or lifestyle, (2) limb salvage in persons with limb-threatening ischemia as manifested by rest pain, nonhealing ulcers, and/or infection or gangrene, and (3) vasculogenic impotence.

Protein kinase C beta/early growth response-1 pathway: a key player in ischemia, atherosclerosis, and restenosis

Atherosclerosis, restenosis, and the consequences of ischemia are the major causes of morbidity and mortality worldwide. Elucidation of key contributing pathways in animal models of ischemia-reperfusion injury, atherosclerosis, and restenosis consequent to vascular injury may lead to great interest in determining if blocking these pathways could prevent vascular disease in human subjects. This review details the evidence that the protein kinase C (PKC) beta/early growth response-1 axis plays a central role in the response to both acute and chronic vascular stresses in animal models and also indicates the clinical implications of a specific inhibitor of PKCbeta, ruboxistaurin (LY333531).

Primary stenting in the treatment of focal atherosclerotic abdominal aortic stenoses

AIM

To evaluate the results of primary stent placement in focal atherosclerotic aortic stenoses using balloon expandable stents.

MATERIALS AND METHODS

Twenty-six primary balloon expandable stent placements in the abdominal aorta were performed and reviewed. All the aortic stenoses were atherosclerotic. Patients were followed up by ankle/brachial pressure indices (ABPI) and Doppler ultrasound (US) at 24h after procedure and at 12 and 24 months. Follow-up angiograms were performed at 12 months.

RESULTS

Twenty-six stents in 26 patients were placed in the infrarenal aorta. All procedures were technically successful and immediate clinical success was obtained. The mean ABPI significantly improved from 0.52+/-0.10 to 0.94+/-0.09 within 24h after procedure, and remained at 0.90+/-0.12 between 12 and 24 months follow-up (mean 18 months). There was full haemodynamic success at hospital discharge and at 12 and 24 months after the procedure. Clinical success at 12 and 24 months (mean 18 months) was defined as an improvement in the Fontaine classification by at least one class compared with the pre-procedure class and was shown to be 100%.

CONCLUSION

In summary, we report that primary stenting is a safe and effective alternative to surgery in cases of symptomatic stenosis of the infrarenal abdominal aorta. The excellent intermediate term results suggested that we would recommend primary stenting as the treatment of choice for focal atherosclerotic stenoses of the infrarenal aorta in selected patients.

Interventionen bei malignen Gallenwegstenosen

This paper gives an overview of experience and success of percutaneous transhepatic interventions in malignant biliary obstruction. Even after exhaustion of surgical and endoscopic therapy options, the percutaneously inserted stents provide effective palliation. The palliative treatment of malignant jaundice using a stent is an established procedure in clinical practice, particularly whenever the endoscopic, transpapillary approach is not possible due to high obstructions or previous surgery. The technical success rate is very high (about 95-100%), and the complication rate is about 10-30%. Since the patency rate of stents is higher than that of plastic endoprostheses, their primary use is justified despite higher costs, provided the patients are adequately selected.

Results and mid–long-term follow-up of stent implantation for native and recurrent coarctation of the aorta

AIMS

Since the late 1980s, endovascular stents have been used in the treatment of several vascular lesions. In the last decades, stent implantation has been proposed as a reliable option for the treatment of coarctation of the aorta. In this setting, it seems to have some advantages, rendering it superior to angioplasty alone.

METHODS AND RESULTS

Between December 1997 and December 2004, 71 consecutive patients (44 males and 27 females) underwent cardiac catheterization for native or recurrent coarctation of the aorta. Seventy-four stents were implanted. All discharged patients were enrolled in a follow-up programme. Every patient underwent clinical evaluation, echo-colour Doppler studies, and exercise ECG at 1 and 6 months after the stent implantation. Peak systolic gradient dropped from 39.3 +/- 15.3 to 3.6 +/- 5.5 mmHg (P = 0.0041). The diameter of the coarcted segment increased from 8.3 +/- 2.9 to 16.4 +/- 3.8 mm (P = 0.037). In our series, one death occurred in a 22-year-old girl with a recurrent coarctation of the aorta, just after stent implantation. The rate of minor complications was <2%. Re-dilatation of a previously implanted stent was performed in three patients.

CONCLUSION

In our experience (the largest reported to the best of our knowledge), stenting of a coarctation/re-coarctation of the aorta represents a safe alternative treatment without a significant mid-long-term complication.

Long-term outcomes and predictors of iliac angioplasty with selective stenting

OBJECTIVE

To review our 11-year experience of iliac angioplasty with selective stenting and to evaluate the safety, short- and long-term patency, clinical success rates, and predictive risk factors in patients with iliac artery occlusive disease.

METHODS

From August 1993 to November 2004, 151 iliac lesions (149 stenoses, 2 occlusions) in 104 patients were treated by percutaneous transluminal angioplasty (PTA). The patients had chronic limb ischemia described as disabling claudication (the Society for Vascular Surgery clinical category 2 or 3) in 76 (50%), rest pain (category 4) in 38 (25%), and ulcer/gangrene (category 5) in 37 (25%). Forty-six limbs (30%) were treated with concomitant infrainguinal endovascular (36, 24%) or open procedures (10, 6%). Thirty-four limbs (23%) had one or more stents placed for primary PTA failure, including residual stenosis (> or =30%), mean pressure gradient (> or =5 mm Hg), or dissection (stent group); whereas, 117 limbs (77%) underwent PTA alone (PTA group). The affected arteries treated were 28 (19%) common iliac, 31 (20%) external iliac, and 92 (61%) both arteries. According to TransAtlantic Inter-Society Consensus (TASC) classification, 39 limbs (26%) were in type A, 71 (47%) in type B, 36 (24%) in type C, and 5 (3%) in type D. Reporting standards of the Society for Vascular Surgery and the International Society for Cardiovascular Surgery were followed.

RESULTS

There was no perioperative death. Total complication rate was 0.7% (one groin hematoma). The mean follow-up was 21 months (median, 10; range, 1 to 94 months). Only 9 (8%) of 117 of the PTA group had subsequent stent placement for recurrent stenosis. The iliac lesions were more severe and extensive in the stent group than those in the PTA group according to TASC classification (Mann-Whitney U test [M-W], P < .0001) and anatomic location (M-W, P = .0019). The technical success rate was 99%, and the initial clinical success rate was 99%. Overall, the cumulative primary patency rates at 1, 3, and 5 years were 76%, 59%, and 49% (Kaplan-Meier [K-M]). The cumulative assisted primary and secondary patency rates at 7 years were 98% and 99% (K-M). The mean number of subsequent iliac endovascular procedures was 1.4 per limb in patients with primary failure of iliac angioplasty/stenting. The continued clinical improvement rates at 1, 3, and 5 years were 81%, 67%, and 53% (K-M). The limb salvage rates at 7 year were 93% (K-M). Of 15 predictor variables studied in 151 iliac lesions, the significant independent predictors for adverse outcomes were smoking history (P = .0074), TASC type C/type D lesions (P = .0001), and stenotic ipsilateral superficial femoral artery (P = .0002) for the primary patency rates; chronic renal failure with hemodialysis (P = .014), ulcer/gangrene as an indication for PTA (P < .0001), and stenotic ipsilateral superficial femoral artery (P = .034) for the continued clinical improvement (K-M, log-rank test and Cox regression model).

CONCLUSIONS

Although the primary patency rates were not high, the assisted primary and secondary patency rates were excellent without primary stenting. Overall, >70% of iliac lesions were treated successfully with PTA alone. The results of this study show that selective stenting offers satisfactory assisted primary and secondary long-term patency after iliac angioplasty. Patients with TASC type C/type D iliac lesions, a stenotic ipsilateral superficial femoral artery, ulcer/gangrene, smoking history, and chronic renal failure with hemodialysis should be followed carefully after endovascular iliac revascularization. These risk factors could be considered indications for primary stenting, although further studies are needed to confirm this.

Management of peripheral arterial disease

Peripheral arterial disease (PAD) may be asymptomatic, may be associated with intermittent claudication, or may be associated with critical limb ischemia. Coronary artery disease (CAD) and other atherosclerotic vascular disorders may coexist with PAD. Persons with PAD are at increased risk for all-cause mortality, cardiovascular mortality, and mortality from CAD. Modifiable risk factors such as cessation of cigarette smoking and control of dyslipidemia, hypertension, and diabetes should be treated. Statins reduce the incidence of intermittent claudication and improve exercise duration until the onset of intermittent claudication in persons with PAD and hypercholesterolemia. Antiplatelet drugs such as aspirin or clopidogrel, especially clopidogrel, and angiotensin-converting enzyme inhibitors should be given to all persons with PAD. beta-Blockers should be given if CAD is present. Exercise rehabilitation programs and cilostazol improve exercise time until intermittent claudication. Indications for lower-extremity angioplasty, preferably with stenting, or bypass surgery are 1) incapacitating claudication in persons interfering with work or lifestyle; 2) limb salvage in persons with limb-threatening ischemia as manifested by rest pain, nonhealing ulcers, and/or infection or gangrene; and 3) vasculogenic impotence. However, amputation should be performed if tissue loss has progressed beyond the point of salvage, if surgery is too risky, if life expectancy is very low, or if functional limitations diminish the benefit of limb salvage.

Endovascular Interventions in Iliac and Infrainguinal Occlusive Artery Disease

Percutaneous endovascular procedures are increasingly applied to treat symptomatic peripheral occlusive artery disease. While the primary technical success and recanalization rates in iliac and infrainguinal interventions are high, differences in the long-term patency rates exist with respect to the anatomic localization, separating the iliac, femoropopliteal, and infrapopliteal arterial regions. In iliac arteries, even complex lesions can be recanalized with good long-term patency rates, especially when using self-expanding nitinol stents. In the infrainguinal arteries the method of choice is still under debate (e.g., balloon angioplasty vs stent implantation). A high restenosis rate represents one of the major limitations in femoropopliteal and infrapopliteal interventions. Therefore, additional methods and treatment strategies for peripheral interventions with the potential for future applications are under investigation and will be discussed such as drug-eluting stents, brachytherapy, subintimal angioplasty, laser angioplasty, atherectomy/thrombectomy, cutting balloon, polytetrafluoroethylene (PTFE)-covered stent grafts, biodegradable stents, and cryoplasty. The increasing amount of data on successful peripheral interventions supports the necessity to adapt and reevaluate the current consensus guidelines that were put together in 2000.

Percutaneous treatment of transplant renal artery stenosis in children

Percutaneous treatment of renal artery stenosis (RAS) is an accepted procedure and numerous reports have been published. However, experience with its use in RAS in the transplanted kidney in children is scarce. Since 1994 we have diagnosed RAS in seven children with the use of Doppler ultrasonography (US), confirming it with percutaneous angiography (PAG). In six of the seven patients percutaneous transluminal angioplasty (PTA) was performed. In one patient a metallic stent was placed due to the extension of the arterial lesion, and a second stent was placed in another child when a re-stenosis was diagnosed 1 month after the PTA. All patients presented with hypertension (de novo or 30% increase over previous values). After ruling out acute rejection, calcineurin inhibitor toxicity, and urinary obstruction, US was performed and, when an increase in arterial flux velocity was registered, PAG was also performed. Six children showed an increase in serum creatinine (Cr) and proteinuria. Blood pressure decreased after the procedure and Cr returned to previous levels in all children. One of the grafts was lost due to chronic transplant rejection 7 years later. The other children have a functioning kidney. Although this is a small group of patients, the consistently good results and the lack of reported experience prompted us to communicate our preliminary observation.

The Nitinol SMART Stent vs Wallstent for Suboptimal Iliac Artery Angioplasty: CRISP-US Trial Results

PURPOSE

The Cordis Randomized Iliac Stent Project-US (CRISP-US) trial evaluated, with an equivalence design, the performance of the shape memory alloy recoverable technology (SMART) nitinol self-expanding stent and the stainless steel Wallstent for treating iliac artery disease after suboptimal percutaneous transluminal angioplasty (PTA).

MATERIALS AND METHODS

This multicenter, prospective, randomized trial comprised 203 patients with chronic limb ischemia who received either the SMART stent (n = 102) or the Wallstent (n = 101) after suboptimal PTA. The primary equivalence end point was a composite of 9-month restenosis, 30-day death, and 9-month target vessel revascularization. Functional, clinical, and hemodynamic assessments were made at hospital discharge and at 1, 6, 9, and 12 months.

RESULTS

The 9-month composite end point rate was equivalent for the SMART stent and Wallstent (6.9% vs 5.9%), with low rates of restenosis (3.5% vs 2.7%), death (2.0% vs 0.0%), and revascularization (2.0% vs 4.0%) in the two groups. Primary patency at 12 months was 94.7% and 91.1% with the SMART stent and Wallstent, respectively. Functional and hemodynamic improvement was also comparable between the groups. The acute procedural success rate was higher in the SMART stent group (98.2% vs 87.5%; P =.002). The frequency of major adverse events was similar at 1 year (4.9% vs 5.9%).

CONCLUSIONS

The performance of the SMART stent was equivalent to that of the Wallstent for treating iliac artery stenosis. The design characteristics of the SMART stent may contribute to greater procedural success and more accurate stent deployment.

Management of peripheral arterial disease of the lower extremities in elderly patients

The prevalence of peripheral arterial disease (PAD) increases with age. PAD in elderly persons may be asymptomatic, may be associated with intermittent claudication, or may be associated with critical limb ischemia. Other atherosclerotic vascular disorders, especially coronary artery disease (CAD), may coexist with PAD. Elderly persons with PAD are at increased risk for all-cause mortality, cardiovascular mortality, and mortality from CAD. Modifiable risk factors should be treated in persons with PAD such as cessation of cigarette smoking and control of hypertension, dyslipidemia, and diabetes. Statins have been shown to reduce the incidence of intermittent claudication and to improve treadmill exercise duration until the onset of intermittent claudication in persons with PAD and hypercholesterolemia. Antiplatelet drugs such as aspirin or clopidogrel, especially clopidogrel, should be administered to all persons with PAD. Persons with PAD should be treated with angiotensin-converting enzyme inhibitors and also with beta blockers if CAD is present. Cilostazol should be given to persons with intermittent claudication to improve exercise capacity unless heart failure is present. Exercise rehabilitation programs improve exercise time until claudication. Indications for lower extremity angioplasty, preferably with stenting, or bypass surgery are 1) incapacitating claudication in persons interfering with work or lifestyle; 2) limb salvage in persons with limb-threatening ischemia as manifested by rest pain, nonhealing ulcers, and/or infection or gangrene; and 3) vasculogenic impotence. However, amputation should be performed if tissue loss has progressed beyond the point of salvage, if surgery is too risky, if life expectancy is very low, or if functional limitations obviate the benefit of limb salvage.

A ?mouse in a trap? method for cerebral protection during carotid stenting: Technical note

Carotid artery angioplasty and stenting (CAS) is now used as an alternative to surgical endarterectomy. The introduction of cerebral protection systems during stenting has improved carotid artery stenosis treatment, with less periprocedural complications. A "mouse in a trap" method was conceived and used in three patients. This involved an emboli entrapment-aspiration system using one proximal occluder in the common carotid artery and two distal occluders in the internal carotid artery or external carotid artery, followed by serial inflation-deflation cycles during each carotid stenting procedure. Debris was retrieved before dilation in one patient, after deployment in one, and after dilation in two. Although only used in a few cases to date, the method may improve the practice of CAS in treating patients with carotid stenosis, resulting in less thromboembolic events.

Primary utilization of stents in angioplasty of superficial femoral artery

Percutaneous transluminal angioplasty (PTA) of infrainguinal arteries has been frequently reported in the literature. Independent of the technical feasibility, the results, in short-and long-term follow-up differ among published series. The objective of this article was to assess the long-term results of angioplasty in small, (<3 cm) segmental lesions of the superficial femoral artery treated with primary stenting. Eighteen patients (12 men, 6 women) with lesions of the superficial femoral artery smaller than 3 cm were selected for endovascular treatment and follow-up. The median patient age was 65 years (range, 54 to 84). The indication for treatment was intermittent claudication in 7 patients and critical ischemia (ischemic pain associated with trophic lesions) in 11 patients (62%). Of these, 13 lesions were stenoses and 5 total occlusions. The run-off was good in 15 patients who had more than 2 distal arteries and 3 had only 1 patent artery. During follow-up, all patients were observed with physical examination, progressive exercise treadmill test; pulse volume was measured with Doppler and duplex scan after 1, 3, and 6 months, and then twice a year. There was only 1 primary failure; the initial success rate was 94%. During follow-up of 40 months (6 to 70 months), only 1 patient presented with thrombosis of the stent 6 months after the procedure. There was no symptomatic restenosis in our study. One patient suffered an acute myocardial infraction after 45 months and died. The primary patency after 1 and 3 years was 88%. No patient was lost to follow-up. Primary stenting of segmental lesions (less than 3 cm) of the superficial femoral artery produced satisfactory results immediately and during long-term follow-up.

Selection of stents for treating iliac arterial occlusive disease

Intravascular stents play an increasingly important role in the treatment of iliac artery occlusive disease and their use has expanded the indications for percutaneous endoluminal therapies. The past several years have seen a sharp increase in the number of commercially available covered and uncovered stents. Knowledge of their design and mechanical properties is crucial for selecting the appropriate stent for a particular type of lesion. In this article, the indications for and results of iliac artery stent placement are reviewed and the various characteristics of the currently available stents that may influence operator choice for use in specific lesions are discussed.

Experience on endothelial cell adhesion on vascular stents and stent-grafts: first in vitro results

RATIONALE AND OBJECTIVES

To evaluate endothelial cell (EC) attachment on different stents and stent-grafts combined with different coating materials.

MATERIALS AND METHODS

Three segments (approximately 1cm(2) each) of Cragg-, Memotherm-, Palmaz-, Strecker-, and Wall-stents, uncovered or covered with polytetrafluoroethylene (PTFE), polyurethane (PU) or polyester (Dacron) were precoated with fibronectin and seeded in vitro under steady conditions with 2 x 10(5) human venous EC/cm(2) for 2 days. EC attachment and morphology was assessed by scanning electron microscopy.

RESULTS

Superior EC attachment on uncovered stents was seen on Memotherm-, Palmaz-, and Wall-stent. On uncovered Cragg- and Strecker-stent only a few single and rounded EC could be detected. PTFE-covering lead to an equal or decreased EC coverage in comparison with the uncovered prostheses. An increase in EC coverage on PU-covered stents was seen and on polyester covered stents as compared with uncovered stents.

CONCLUSION

In vitro, EC attachment is clearly different on vascular stents and stent-grafts, probably depending on the material of the stents stent and unknown manufacturing related components. When EC adhesion is desired and stent covering is used, the choice of covering material may influence EC adhesion.

Carotid artery stenting protected with an emboli containment system

BACKGROUND AND PURPOSE

Fear of distal embolization and stroke has aroused concern regarding carotid stenting. Devices to protect the cerebral circulation may make carotid stenting safer.

METHODS

A multidisciplinary study group tested a balloon occlusion-aspiration emboli entrapment device in conjunction with carotid stenting. The device consists of an elastomeric balloon on a steerable wire with a detachable adapter that inflates and deflates the distal temporary occlusion balloon. An aspiration catheter is used to remove trapped emboli after stenting and before occlusion balloon deflation.

RESULTS

Seventy-five patients with severe internal carotid artery stenosis were treated with stents deployed with this cerebrovasculature protection system. All 75 patients (100%) had grossly visible particulate material aspirated, and all were treated successfully without major or minor stroke or death at 30 days. Preintervention stenosis was 81+/-10%, and residual stenosis was 5+/-7%. Nine patients (12%) had angiographic evidence of thrombus before intervention, but no patient had thrombus or vessel cutoff after the procedure. Four patients (5%) developed transient neurological symptoms during protection balloon occlusion, but symptoms resolved with balloon deflation. The 22 to 667 particles aspirated per patient ranged from 3.6 to 5262 microm in maximum diameter (mean, 203+/-256 microm). These particles included fibrous plaque debris, lipid or cholesterol vacuoles, and calcific plaque fragments.

CONCLUSIONS

Protected carotid stenting was performed successfully and safely in this study early in the experience with cerebrovascular protection devices. Particulate emboli are frequent with stenting, and cerebral protection will likely be necessary to minimize stroke. Randomized trials comparing protected carotid stenting with endarterectomy are warranted.

Vascular reconstructive options in the ischemic foot

Aggressive evaluation and treatment of the patient suffering from lower-extremity ischemia is critical. Vascular reconstruction can be performed to enhance healing and to decrease the incidence of major limb amputation and therefore return these patients to active and productive life.

Stenting of coarctation of the aorta

The purpose of the present study was to assess the usefulness of balloon expandable Palmaz intravascular stents in the transcatheter treatment of children and young adults with native and recurrent coarctation of the aorta, and to develop an improved intravascular stent and balloon delivery catheter specifically developed for vascular obstructions associated with congenital heart disease, including coarctation of the aorta. Twenty-one patients, 8 native and 13 recurrent coarctations, were successfully treated with the Palmaz stent. However, limitations and disadvantages in stent design and the single balloon delivery system were uncovered. Therefore, the NuMED CP stent and BIB delivery catheter were developed and used to treat 25 patients with native (17) and recurrent (8) coarctation successfully. Improvements in stent design and long-term follow-up using three-dimensional spiral CT scan will be helpful in determining the role of transcatheter stent therapy for native and recurrent coarctation of the aorta. Cathet Cardiovasc Intervent 2001;54:112-125.

Noninvasive evaluation before and after percutaneous therapy of iliac artery stenoses: the value of the Bernoulli-predicted pressure gradient

PURPOSE

The purpose of this study was to assess the value of the Bernoulli-predicted pressure gradient in the noninvasive evaluation of patients undergoing iliac percutaneous transluminal angioplasty (PTA) or stent placement with the use of intra-arterial pressure measurements as the standard of reference.

METHODS

Stent placement or PTA was performed in 261 patients with intermittent claudication caused by iliac artery stenoses (333 procedures). Intra-arterial translesional pressure gradients were recorded before and after each procedure. Hemodynamic success was defined as a postprocedural mean pressure gradient less than or equal to 10 mm Hg at rest and during vasodilatation. Before and after intervention, the following noninvasive parameters were determined: the Bernoulli-predicted pressure gradient, the peak systolic velocity ratio, and the ankle-brachial pressure index.

RESULTS

Before treatment, both the intra-arterial-measured pressure gradients and the Bernoulli-predicted gradients indicated hemodynamic significance of the iliac artery stenoses. After treatment, both methods indicated significant improvement of the translesional pressure gradient (P <. 0001). However, the correlation between the intra-arterially measured pressure gradient and the Bernoulli-predicted gradient of iliac artery stenoses was low (Pearson's r = 0.27). None of the three investigated noninvasive methods could differentiate an optimal PTA or stent result from a suboptimal result, as assessed by intra-arterial pressure measurements.

CONCLUSIONS

The disappointing correlation among the duplex velocity data, whether expressed as pressure gradient or as a peak systolic velocity ratio, and the actually measured pressure gradient might be caused by errors in pressure or velocity measurements or the different circumstances in which the pressure or velocity measurements were performed. Residual pressure gradients after iliac PTA or stent placement assessed with intra-arterial pressure measurements could not be assessed with the investigated noninvasive methods.

Endovascular therapy of iliac arteries: routine application of intraluminal stents does not improve clinical patency

Our objective in this study was to review our experience with endovascular therapy of iliac artery occlusive disease over the past decade, and to compare the results of angioplasty alone with the addition of endovascular stents to these procedures. This report details a retrospective analysis of clinical data on 141 consecutive patients with iliac artery occlusive disease, treated by balloon angioplasty alone, or with the addition of intraluminal stents. The procedures analyzed included 58 common iliac artery interventions (26 angioplasties and 32 stent insertions) and 83 external iliac artery procedures (43 angioplasties and 40 stent insertions). Early and continued success, and their components, are reported and compared according to published standards. While endovascular therapy of iliac artery occlusive disease is effective in relieving symptoms, clinical patency rates are lower than those reported for direct reconstruction. Primary stent placement has not enhanced clinical patency in the iliac arteries, and the selective insertion of these devices for more complicated angioplasty procedures seems warranted.

Percutaneous transluminal angioplasty and stenting for iliac artery occlusive disease

Atherosclerotic iliac artery stenoses respond well to simple balloon angioplasty and have the best results of all of the peripheral vessels. Nonetheless, initial technical failures occur in as many as 20% of patients, most of which can be salvaged with intravascular stenting, as can many of the potential complications; however, even though the initial technical success rates for stenting approach 100%, stenotic recurrences within stents are not infrequent. Whether promising new concepts, such as brachytherapy, gene therapy, and endoluminal grafting, will have a durable impact on the results of iliac angioplasty is yet to be seen. Meanwhile, the excellent results of endoluminal treatment of patients with iliac artery occlusive disease, combined with the relatively low risk for complications compared with surgical revascularization, ensure an enduring role for this modality of treatment and a diminution in the fraction of patients requiring surgery to correct their iliac artery occlusive disease.