Aortoiliac Insufficiency: Long-term Experience with Stent Placement for Treatment

Balloon-expandable cobalt chromium stent versus self-expandable nitinol stent for the Atherosclerotic Iliac Arterial Disease (SENS-ILIAC Trial) Trial: a randomized controlled trial

Iliac artery angioplasty with stenting is an effective alternative treatment modality for aortoiliac occlusive diseases. Few randomized controlled trials have compared the efficacy and safety between self-expandable stent (SES) and balloon-expandable stent (BES) in atherosclerotic iliac artery disease. In this randomized, multicenter study, patients with common or external iliac artery occlusive disease were randomly assigned in a 1:1 ratio to either BES or SES. The primary end point was the 1-year clinical patency, defined as freedom from any surgical or percutaneous intervention due to restenosis of the target lesion after the index procedure. The secondary end point was a composite event from major adverse clinical events at 1 year. A total of 201 patients were enrolled from 17 major cardiovascular intervention centers in South Korea. The mean age of the enrolled patients was 66.8 ± 8.5 years and 86.2% of the participants were male. The frequency of critical limb ischemia was 15.4%, and the most common target lesion was in the common iliac artery (75.1%). As the primary end point, the 1-year clinical patency as primary end point was 99% in the BES group and 99% in the SES group (p > 0.99). The rate of repeat revascularization at 1 year was 7.8% in the BES group and 7.0% in the SES group (p = 0.985; confidence interval, 1.011 [0.341-2.995]). In our randomized study, the treatment of iliac artery occlusive disease with self-expandable versus balloon-expandable stent was comparable in 12-month clinical outcomes without differences in the procedural success or geographic miss rate regardless of the deployment method in the distal aortoiliac occlusive lesion (ClinicalTrials.gov, NCT01834495).

Endovascular Revascularization Plus Supervised Exercise Versus Supervised Exercise Only for Intermittent Claudication: A Cost-Effectiveness Analysis

[Figure: see text].

Bare Stents for Iliac Chronic Total Occlusions ("TELIS"): A Prospective Cohort Study with a Midterm Follow-up

BACKGROUND

This study aims to assess primary bare stenting for iliac chronic total occlusions (CTOs) with midterm follow-up.

METHODS

From April 2013 to May 2016, all patients presenting with symptomatic iliac CTO were treated endovascularly and included in a prospective single-center cohort. Common iliac CTOs were treated with balloon-expandable bare-metal stents. External iliac lesions were treated with bare self-expandable nitinol stents. Primary end point was primary sustained clinical improvement. A total of 49 iliac CTOs were treated in 46 patients.

RESULTS

A total of 22 lesions were located at the level of the common iliac artery (45%), 20 at the external iliac artery (41%), and 7 extending to both (14%). Mean stenting length was 114.4 ± 49.8 mm. Technical success was 98%. Primary sustained clinical improvement was achieved for 93.4 ± 3.7% of patients at 12 months and 87.7 ± 5.2% at 24 months. Three in-stent thrombosis were observed with no restenosis in the remaining patients at 24 months. Freedom from target lesion revascularization was 93.3% ± 3.7% at 24 months. Three stent fractures were noted, none were symptomatic. Mean quality of life (EQ5D-3L) was significantly improved at 24 months (71.2 ± 20.3 vs. 52.4 ± 22.6, P = 0.001).

CONCLUSIONS

Our results showed that primary bare-metal stenting for iliac CTO is safe and efficient at 24 months and could be considered as a first-line strategy.

Clinical outcomes of endovascular treatment for chronic aortic occlusion: a retrospective multicentre registry: EVT for chronic aortic occlusion

AIMS

The aim of this study was to evaluate the clinical outcomes of endovascular treatment (EVT) for chronic aortic occlusion (CAO) using multicentre registry data.

METHODS AND RESULTS

From April 2003 to December 2015, data on 73 consecutive patients (55 men and 18 women; aged 70.7±12.2 years) who underwent EVT for CAO were collected retrospectively from 15 centres in Japan. The primary endpoint was the primary patency at 12 months after EVT. Secondary endpoints were procedural success and periprocedural complication rates. We analysed 67 patients who underwent complete endovascular revascularisation after 2007. Initial procedural success was achieved in 63 cases (94.0%). Complications occurred in three patients (4.5%) (stroke, n=1; distal embolism, n=1; access-site haematoma requiring blood transfusion, n=1). In patients after successful EVT (n=63), the primary and secondary patency rates at 12 months were 90.7% and 97.7%, respectively. During a mean follow-up period of 17.8 months, restenosis/re-occlusion was observed in eight patients (12.7%).

CONCLUSIONS

EVT for CAO could be performed safely with a high procedural success rate. The short-term clinical outcome was acceptable despite lesion complexity.

Midterm Results of Low-Profile Stents to Treat Atherosclerotic Iliac Artery Disease

PURPOSE

To evaluate the safety and effectiveness of low-profile 4-F stents for the treatment of atherosclerotic iliac artery lesions.

METHODS

Between January 2009 and December 2015, 63 patients (mean age 69.3 years; 42 men) received low-profile stents (Astron Pulsar or Pulsar-18) at the discretion of the operator to treat iliac artery occlusive disease. The majority of patients (40, 63.5%) had critical limb ischemia; 36 of 82 lesions were total occlusions. All procedures were performed with 4-F equipment. Outcomes evaluated included mortality, patency (primary, assisted primary, and secondary), absence of target lesion revascularization (TLR), and limb salvage. Associations of patient and procedure variables with patency and TLR outcomes were sought with univariate and multivariate analysis.

RESULTS

Via a brachial (n=46/63) or femoral (n=17/63) access, 82 stents were successfully deployed to treat the 82 lesions, with <30% residual stenosis. The overall access-related complication rate was 1.6% (brachial artery occlusion). Mean duration of follow-up was 24.1±22.3 months (range 1-72), during which 3 patients died and 1 major amputation occurred at 10 months. The 4-year Kaplan-Meier estimate of primary patency was 76.9% (95% CI 70.2% to 83.6%); the assisted primary and secondary patency estimates were 79.3% (95% CI 73% to 85.6%) and 91% (95% CI 84.5% to 97.5%). The 4-year freedom from TLR estimate was 73.8% (95% CI 67.4% to 80.2%). On multivariate analysis, the only associations confirmed involved Rutherford category 5/6 with primary patency (hazard ratio [HR] 5.7, 95% CI 4.4 to 7, p=0.02) and assisted primary patency (HR 6.1, 95% CI 4.9 to 7.3, p=0.01).

CONCLUSION

Use of a low-profile 4-F stent in atherosclerotic iliac lesions was safe and effective. At 4 years, the overall patency and the absence of TLR were good. Midterm outcomes were poor in patients with Rutherford category 5/6 ischemia. Finally, the use of stents with a ≥6-mm diameter and postdeployment balloon dilation are recommended in all cases.

First-in-Human Experience With the Gore Balloon-Expandable Covered Endoprosthesis in Iliac Artery Occlusive Disease

Purpose: To report the first-in-human iliac artery experience of a new balloon-expandable covered endoprosthesis. Methods: A prospective, single-center pilot study recruited 30 symptomatic patients (mean age 64 years; 18 men) to evaluate the safety and early efficacy of the new Gore balloon-expandable covered endoprosthesis for the treatment of de novo or restenotic common and/or external iliac artery lesions. According to protocol, up to 2 discrete lesions could be treated with a maximum total treated length ≤110 mm. Follow-up included clinical evaluation with duplex ultrasound at 1, 6, and 12 months. Data are presented through 12-month follow-up. The primary safety endpoint was a composite of device- or procedure-related death, myocardial infarction, or amputation in the treated leg within 30 days of the index procedure. Multiple performance outcomes were also evaluated. Results: The primary 30-day safety endpoint was 0%. Per-subject estimates of primary patency, freedom from target lesion revascularization, and freedom from target vessel revascularization were 100% at 1 and 6 months and 96.6% at 12 months. Estimates of assisted primary and secondary patency were both 100% at 12 months. Freedom from major adverse events at 12 months was 100%. Most patients experienced improvements in Rutherford category, ankle-brachial index, and functional status that were sustained to 12 months. Conclusion: This positive first-in-human experience with the Gore balloon-expandable covered endoprosthesis suggests this device will have an important role in the management of aortoiliac occlusive disease.

Efficacy and Safety of Endovascular Therapy for Aortoiliac TASC D Lesions

Background:

Although there is increasing evidence of the effectiveness of endovascular therapy for complex aortoiliac (AI) occlusive disease, it is not universally applied to TASC D lesions.

Methods:

A total of 2096 patients, 2601 limbs with AI occlusive disease, were enrolled. The lesions were categorized as TASC D (395) or TASC A-C (2206), and we compared baseline data, procedure, and follow-up result between the 2 groups.

Results:

The success rate of the procedure was significantly lower in the TASC D group (91.6% vs 99.3%, P < .01), and more procedure complications occurred in the TASC D group (11.1% vs 5.2%, P < .01). The results of a 5-year follow-up revealed no significant difference in primary patency (77.9% vs 77.1%, P = .17) and major adverse cardiovascular and limb events (MACLE; 30.5% vs 33.4%, P = .42) between the 2 groups. A multivariate analysis revealed complications and critical limb ischemia are independent predictors of MACLE in the TASC D group.

Conclusion:

The success rate of the procedure was lower in the TASC D group. Complications were more frequent in the TASC D group, and they were related to MACLE.

Study design and rationale of the 'Balloon-Expandable Cobalt Chromium SCUBA Stent versus Self-Expandable COMPLETE-SE Nitinol Stent for the Atherosclerotic ILIAC Arterial Disease (SENS-ILIAC Trial) Trial': study protocol for a randomized controlled trial

Background

The self-expandable COMPLETE™ stent (Medtronic) has greater elasticity, allowing it to regain its shape after the compression force reduces, and has higher trackability, thus is easier to maneuver through tortuous vessels, whereas the balloon-expandable SCUBA™ stent (Medtronic) has higher radial stiffness and can afford more accurate placement without geographic miss, which is important in aortoiliac bifurcation lesions. To date, there have been no randomized control trials comparing efficacy and safety between the self-expanding stent and balloon-expandable stent in advanced atherosclerotic iliac artery disease.

Methods/design

The purpose of our study is to examine primary patency (efficacy) and incidence of stent fracture and geographic miss (safety) between two different major representative stents, the self-expanding nitinol stent (COMPLETE-SE™) and the balloon-expanding cobalt-chromium stent (SCUBA™), in stenotic or occlusive iliac arterial lesions. This trial is designed as a prospective, randomized, multicenter trial to demonstrate a noninferiority of SCUBA™ stent to COMPLETE-SE™ stent following balloon angioplasty in iliac arterial lesions, and a total of 280 patients will be enrolled. The primary end point of this study is the rate of primary patency in the treated segment at 12 months after intervention as determined by catheter angiography, computed tomography angiography, or duplex ultrasound.

Discussion

The SENS-ILIAC trial will give powerful insight into whether the stent choice according to deployment mechanics would impact stent patency, geographic miss, or stent fracture in patients undergoing stent implantation in iliac artery lesions.

Trial registration

National Institutes of Health Clinical Trials Registry (ClinicalTrials.gov identifier: NCT01834495), registration date: May 8, 2012

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1435-9) contains supplementary material, which is available to authorized users.

Supervised exercise, stent revascularization, or medical therapy for claudication due to aortoiliac peripheral artery disease: the CLEVER study

BACKGROUND

Treatment for claudication that is due to aortoiliac peripheral artery disease (PAD) often relies on stent revascularization (ST). However, supervised exercise (SE) is known to provide comparable short-term (6-month) improvements in functional status and quality of life. Longer-term outcomes are not known.

OBJECTIVES

The goal of this study was to report the longer-term (18-month) efficacy of SE compared with ST and optimal medical care (OMC).

METHODS

Of 111 patients with aortoiliac PAD randomly assigned to receive OMC, OMC plus SE, or OMC plus ST, 79 completed the 18-month clinical and treadmill follow-up assessment. SE consisted of 6 months of SE and an additional year of telephone-based exercise counseling. Primary clinical outcomes included objective treadmill-based walking performance and subjective quality of life.

RESULTS

Peak walking time improved from baseline to 18 months for both SE (5.0 ± 5.4 min) and ST (3.2 ± 4.7 min) significantly more than for OMC (0.2 ± 2.1 min; p < 0.001 and p = 0.04, respectively). The difference between SE and ST was not significant (p = 0.16). Improvement in claudication onset time was greater for SE compared with OMC, but not for ST compared with OMC. Many disease-specific quality-of-life scales demonstrated durable improvements that were greater for ST compared with SE or OMC.

CONCLUSIONS

Both SE and ST had better 18-month outcomes than OMC. SE and ST provided comparable durable improvement in functional status and in quality of life up to 18 months. The durability of claudication exercise interventions merits its consideration as a primary PAD claudication treatment.

[Usefulness of virtual vessel images in ppi for treatment of complete obstruction of leg arteries]

Following recent rapid advances in devices and treatment technology, indications for percutaneous peripheral intervention (PPI) have been expanded to include complex lesions (long-segment lesions, completely obstructed chronic lesions, etc.) and even lesions of the superficial femoral artery and arteries distal to the popliteal artery. However, when PPI is used for treatment of complete obstruction, treatment can take a long time or its outcome can be less satisfactory for reasons such as difficulty in assessing the vascular distribution/arrangement or the direction of calcification in the obstructed area or excessively long lesions. In the present study, we conducted three-dimensional image processing of CT data from leg arteries conventionally used for preoperative diagnosis. Using this processing technique, we created virtual images of the blood vessels of the completely obstructed area and mapped these virtual vessel images onto the fluoroscopic monitor image during catheter treatment. The usefulness of this technique for PPI was then evaluated. We succeeded in creating virtual vessel images of the completely obstructed parts of leg arteries with the use of preoperative CT images of leg arteries that we then mapped onto the fluoroscopic monitor images during treatment. We were successful in mapping virtual images onto the abdominal aorta in 96.8% of cases and in 95.7% with the common iliac artery. This technique is thus able to supply reliable information on vascular distribution/arrangement, suggesting that it can enable the surgeon to advance the treatment device precisely along the vessels, making it useful for treatment with PPI. The study additionally showed that differences in the angle of imaging affect the manual mapping of the CT images onto angiograms.

Long-term outcomes of endovascular therapy for aortoiliac bifurcation lesions in the real-AI registry

PURPOSE

To report long-term outcomes of endovascular therapy (EVT) for aortoiliac bifurcation lesions.

METHODS

Patients enrolled in the multicenter REtrospective AnaLysis of Aorto-Iliac stenting (REAL-AI) registry in Japan were pooled. Of 2096 patients who underwent EVT for de novo aortoiliac disease between January 2005 and December 2009, 190 patients (148 men; mean age 70±9 years) had aortoiliac bifurcation lesions that were treated with stents, whose configuration (single, V, or kissing) and type (balloon-expandable or self-expanding) were subjected to regression analysis to determine any impact on primary patency along with other demographic, clinical, and lesion characteristics, including Trans-Atlantic Inter-Society Consensus II C/D classification. The primary endpoints were restenosis and target lesion revascularization (TLR). Secondary endpoints were all-cause death, major cardiovascular events, and major cardiovascular + limb events.

RESULTS

The overall complication rate was 6.3%, and 1- and 5-year primary patency rates were 87% and 73%, respectively. Over a mean follow-up of 31±15 months, there were 36 (19.0%) restenoses, 22 (11.6%) TLRs, and 4 (2.1%) reocclusions; stent fracture (2, 1.1%) and major amputation (2, 1.1%) were rare. Only female gender [adjusted hazard ratio (AHR) 4.26, 95% CI 1.89 to 9.71, p<0.001] and residual diameter stenosis (AHR 1.04, 96% CI 1.01 to 1.06, p=0.01) were independent predictors of primary patency.

CONCLUSION

Stenting for aortoiliac bifurcation lesions was found to be safe and effective. Neither stent configuration nor type appeared to affect vessel patency in true bifurcation lesions.

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.

[Occlusion of the aorta and iliac arteries]

Occlusion of the aorta and the iliac arteries leads to an insufficient perfusion of the legs and the genital and gluteal region. The occurring symptoms may be variable, mainly depending on the collateralization network of the internal iliac artery (IIA) circulation. Various differential diagnoses need to be excluded. Invasive therapy is almost always inevitable if an aortoiliac stenosis is established. With good patency rates and low mortality rates the indications for reconstructive procedures are liberally interpreted; therefore, invasive therapy can be performed in the early stages of claudication in certain situations. Due to lower invasiveness and therefore lower risk of complications while showing comparable long-term patency rates, endovascular treatment is the preferred first line therapy for the majority of occlusions. Because aortoiliac occlusion processes also affect patients who are actively involved in a professional career, the indications for invasive therapy can be attained even in Fontaine stage IIa.

Increasing role of interventional cardiologists for peripheral vascular disease

Improvements in the design of endovascular devices and technical skills of interventionalists have opened new possibilities for patients with a wide range of peripheral vascular diseases. In lower extremity peripheral artery disease, percutaneous treatments have become the predominant revascularization strategy for simple and complex lesions. Newer generations of stents and drug-coated balloons have demonstrated strong potential in the treatment of femoropopliteal and infrainguinal diseases. One of the most dramatic advances in the recent past has been endovascular repair of thoracic and abdominal aortic aneurysms, which has become the preferred approach in lieu of open surgical repair. Contemporary trials have established the safety and effectiveness of carotid stenting in selected patients with severe stenosis. Endovascular treatments for venous occlusive disease have long been underutilized, but their effectiveness is being increasingly recognized. This review covers new endovascular procedures performed by interventional cardiologists for peripheral vascular diseases.

The influence of gender on patency rates after iliac artery stenting

OBJECTIVE

The purpose of this study was to investigate the influence of gender on the long-term outcome after iliac artery stenting and to assess gender-specific differences of the influence of risk factors on treatment success and patency rates.

METHODS

Between January 2000 and December 2006, 404 percutaneous transluminal angioplasties with primary stent deployment for symptomatic iliac artery occlusive disease were performed at our center. These included 128 interventions in women and 276 interventions in men.

RESULTS

Whereas average age was significantly higher (65.9 ± 12.9 years; P = .007) and arterial hypertension more frequent (60.9% vs 49.3%; P = .032) in women, hyperuricemia (7.0% vs 14.1%; P = .047) and a positive smoking status (61.7% vs 74.3%; P = .014) were more frequently observed in men. Fontaine stage was more advanced (stages III and IV) in women than in men (P = .028; P < .001). Technical success was 97.7% in women and 99.3% in men. Overall complication rate was higher in women compared with men (P = .002), mostly caused by access site hematomas (4.7% vs 0.4%) and pseudoaneurysms (8.6% vs 2.5%). Patients were followed up for 45.0 ± 33.3 months. Restenosis developed in 16.8% of cases in women and in 14.6% of cases in men and was treated in 73.7% by an endovascular approach. Primary patency rates at 1, 3, 5, and 7 years were 90.3%, 77.2%, 60.2%, and 46.4% in women and 89.9%, 71.5%, 63.6%, and 59.7% in men, respectively (P = .524; log-rank, .406). Secondary patency rates were 97.2%, 91%, 81.5%, and 70.3% in women and 97.1%, 89.1%, 82.6%, and 78% in men, respectively (P = .959; log-rank, .003). Multivariate analysis identified lower age as the only independent risk factor for recurrent disease in both groups. Age-defined subgroup analysis showed a restenosis/reocclusion rate of 23.9% in men and 22.1% in women older than 63.5 years (P = .861) but 32.1% in men and 49.1% in women younger than that (P = .034).

CONCLUSIONS

Our data suggest that although women are older and present with a more advanced stage of peripheral arterial occlusive disease, endovascular therapy is equally effective irrespective of gender. Surprisingly, the subgroup of young female patients had a specifically poor outcome.

Mid-term outcomes following endovascular re-intervention for iliac artery in-stent restenosis

OBJECTIVES

We sought to evaluate the procedural characteristics and clinical outcomes of endovascular repair for iliac artery (IA) in-stent restenosis (ISR).

BACKGROUND

An increasing percentage of patients with complex IA occlusive disease are treated with an endovascular approach, but the outcomes of IA-ISR have not been well described.

METHODS

We analyzed all endovascular procedures for treatment of IA-ISR performed at our institution between July 2006-December 2010. The primary outcome was primary patency, defined as <50% stenosis as assessed by clinical examination and duplex ultrasonography (DUS).

RESULTS

Forty-one lesions in 24 patients who underwent repeated endovascular intervention for treatment of IA-ISR. Most lesions were unilateral and involved the common IA (66%). The mean length of ISR was 30.1 ± 14.1 mm with type I (focal) and II (diffuse) ISR occurring with the greatest frequency (34% and 39%, respectively). All patients underwent balloon angioplasty; adjunctive stenting zwas performed in 27 (66%) of the lesions. Type II ISR lesions more frequently required stenting (13/16 lesions, P = 0.02 compared with other patterns of ISR). Procedural success was 100% with a mean gain of 0.13 in the ankle-brachial index (P = 0.001). The 6- and 12-month primary patency rates were 96% and 82%, respectively. The 12-month primary-assisted patency rate was 90% with clinically driven target lesion revascularization (TLR) in three patients.

CONCLUSIONS

Endovascular treatment of IA-ISR using an approach of balloon angioplasty followed by selective stenting is associated with high-patency rates and low rates of TLR at 1 year.

Patients' perspective about risks and benefits of treatment for peripheral arterial disease

PURPOSE

To report the results of a standard gamble-type survey conducted to explore patients' heuristics in regard to therapy for peripheral arterial disease (PAD).

MATERIALS AND METHODS

Patients presenting to a vascular and interventional radiology practice because of suspected PAD were asked to indicate their threshold for risk of amputation during a curative procedure for intermittent claudication (IC) and for risk of death from a curative medication for critical limb ischemia (CLI). Possible relationships of risk threshold with age, gender, ankle-brachial index (ABI), and functional claudication distance were assessed with univariate statistics followed by multivariable generalized linear mixed models of risk acceptance at various risk levels.

RESULTS

Study participants were 20 patients (40% women), with median age of 64 years, functional claudication distance of 1 block, and ABI of 0.72. In the IC scenario, up to 1% risk of above-knee amputation was found to be the median risk acceptable to patients for undergoing a curative procedure. In the CLI scenario, the median risk acceptance for mortality from a curative medication was up to 1%. The multivariable model for the IC scenario revealed significantly greater acceptance of risk at a given level among older patients and women. No significant predictor was delineated by the multivariable model for the CLI scenario.

CONCLUSIONS

Overall, patients have a low threshold for complications of PAD therapy, consistent with endovascular but not with open surgical strategies. However, considerable variation in preferences underlines the value of individualized treatment strategies.

Balloon-expandable stent deformation during deployment into the iliac artery: a procedural complication managed conservatively

The management of aortoiliac insufficiency has been improved considerably since the introduction of balloon-expandable stents in 1991. Although numerous studies have shown the safety and efficacy of balloon-expandable iliac artery stent placement, the procedure is not without potential complication. We report here a very unusual case of iliac artery stenting being complicated by deformation and elongation of the stent following balloon rupture at initial deployment with retention of the distal balloon marker and our successful approach to subsequent management with combined acetylsalicylic acid and clopidogrel. In conclusion, this conservative approach may be an alternative treatment of a partially deployed aortoiliac stent with a retained foreign body when further intervention is considered to be of high risk.

Supervised exercise versus primary stenting for claudication resulting from aortoiliac peripheral artery disease: six-month outcomes from the claudication: exercise versus endoluminal revascularization (CLEVER) study

BACKGROUND

Claudication is a common and disabling symptom of peripheral artery disease that can be treated with medication, supervised exercise (SE), or stent revascularization (ST).

METHODS AND RESULTS

We randomly assigned 111 patients with aortoiliac peripheral artery disease to receive 1 of 3 treatments: optimal medical care (OMC), OMC plus SE, or OMC plus ST. The primary end point was the change in peak walking time on a graded treadmill test at 6 months compared with baseline. Secondary end points included free-living step activity, quality of life with the Walking Impairment Questionnaire, Peripheral Artery Questionnaire, Medical Outcomes Study 12-Item Short Form, and cardiovascular risk factors. At the 6-month follow-up, change in peak walking time (the primary end point) was greatest for SE, intermediate for ST, and least with OMC (mean change versus baseline, 5.8±4.6, 3.7±4.9, and 1.2±2.6 minutes, respectively; P<0.001 for the comparison of SE versus OMC, P=0.02 for ST versus OMC, and P=0.04 for SE versus ST). Although disease-specific quality of life as assessed by the Walking Impairment Questionnaire and Peripheral Artery Questionnaire also improved with both SE and ST compared with OMC, for most scales, the extent of improvement was greater with ST than SE. Free-living step activity increased more with ST than with either SE or OMC alone (114±274 versus 73±139 versus -6±109 steps per hour), but these differences were not statistically significant.

CONCLUSIONS

SE results in superior treadmill walking performance than ST, even for those with aortoiliac peripheral artery disease. The contrast between better walking performance for SE and better patient-reported quality of life for ST warrants further study.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov/ct/show/NCT00132743?order=1. Unique identifier: NCT00132743.

Peripheral artery disease. Part 2: medical and endovascular treatment

The treatment of peripheral artery disease (PAD) focuses on risk factor modification, cardiovascular event reduction, limb viability, and symptom improvement. Hypertension, hyperlipidemia, and diabetes mellitus should all be controlled to recommended target levels, and smoking cessation is vital. Antiplatelet therapies, such as aspirin or clopidogrel, should be administered in all patients unless contraindicated. Whenever possible, patients who present with claudication should be offered a regimen comprised of both medical and exercise therapy, which often results in substantial improvement in symptoms. For patients presenting with more-advanced disease, such as acute limb ischemia, critical limb ischemia, and severely-limiting symptoms of PAD, revascularization is often necessary. As a result of the rapid evolution in endovascular revascularization technology and expertise, many patients with PAD can be treated percutaneously. Therefore, in this Review, we will focus on medical therapy and endovascular revascularization of patients with PAD, with reference to surgical bypass in specific clinical scenarios.

Novel application of the "CART" technique for endovascular treatment of external iliac artery occlusions

We report the novel application of the Controlled Antegrade and Retrograde subintimal Tracking technique for the endovascular treatment of occlusions of the external iliac artery (EIA). We hypothesized that this technique would limit the extent of subintimal dissection to the length of the EIA occlusion, thus preserving patency of the internal iliac artery proximally and the circumflex iliac artery distally and minimizing the length of stent required to treat the occlusion, including the length of stent placed in the common femoral artery. The technical execution and clinical experience with this technique is reported.

Value of information analyses of economic randomized controlled trials: the treatment of intermittent claudication

OBJECTIVE

The aim of this study is to design the optimal study comparing endovascular revascularization and supervised exercise training for patients with intermittent claudication and to demonstrate value of information (VOI) analysis of patient-level data from an economic randomized controlled trial to guide future research.

METHODS

We applied a net benefit framework to patient-level data on costs and quality-of-life of a previous randomized controlled trial. VOI analyses were performed using Monte Carlo simulation. We estimated the total expected value of perfect information (total EVPI), the total expected value of sample information (total EVSI), the partial expected value of perfect information (partial EVPI), and the partial expected value of sample information (partial EVSI). These VOI analyses identified the key parameters and the optimal sample size of future study designs. Sensitivity analyses were performed to explore the robustness of our assumptions about the population to benefit, the willingness-to-pay threshold, and the study costs. The VOI analyses are demonstrated in statistical software (R) and a spreadsheet (Excel) allowing other investigators to apply VOI analysis to their patient-level data.

RESULTS

The optimal study design for the treatment of intermittent claudication involves a randomized controlled trial collecting data on the quality-adjusted life expectancy and additional admission costs for 525 patients per treatment arm. The optimal sample size remained between 400 and 600 patients for a willingness-to-pay threshold between euro30,000 and euro100,000/quality-adjusted life-years, for even extreme assumptions about the study costs, and for a range of 3 to 7 years that future patients will benefit from the results of the proposed study.

CONCLUSIONS

1) The optimal study for patients with intermittent claudication collects data on two key parameters for 525 patients per trial arm; and 2) we have shown that value of information analysis provides an explicit framework to determine the optimal sample size and identify key parameters for the design of future clinical trials.

Endovascular treatment of peripheral vascular disease

Peripheral arterial disease (PAD) affects about 27 million people in North America and Europe, accounting for up to 413,000 hospitalizations per year with 88,000 hospitalizations involving the lower extremities and 28,000 involving embolectomy or thrombectomy of lower limb arteries. Many patients are asymptomatic and, among symptomatic patients, atypical symptoms are more common than classic claudication. Peripheral arterial disease also correlates strongly with risk of major cardiovascular events, and patients with PAD have a high prevalence of coexistent coronary and cerebrovascular disease. Because the prevalence of PAD increases progressively with age, PAD is a growing clinical problem due to the increasingly aged population in the United States and other developed countries. Until recently, vascular surgical procedures were the only alternative to medical therapy in such patients. Today, endovascular practice, percutaneous transluminal angioplasty with or without stenting, is used far more frequently for all types of lower extremity occlusive lesions, reflecting the continuing advances in imaging techniques, angioplasty equipment, and endovascular expertise. The role of endovascular intervention in the treatment of limb-threatening ischemia is also expanding, and its promise of limb salvage and symptom relief with reduced morbidity and mortality makes percutaneous transluminal angioplasty/stenting an attractive alternative to surgery and, as most endovascular interventions are performed on an outpatient basis, hospital costs are cut considerably. In this monograph we discuss current endovascular intervention for treatment of occlusive PAD, aneurysmal arterial disease, and venous occlusive disease.

Endovascular treatment of external iliac artery stenoses for claudication with systematic stenting

The results of the endovascular treatment of external iliac artery lesions in patients with claudication are not well known. In the literature, very often, the studied populations are not homogenous (people with claudication and with acute ischemia) and the external iliac artery is not differentiated from the primary iliac artery. Moreover, systematic stenting is still debated. Our goal was to study the results of systematic stenting for atheromatous lesions of the external iliac artery in a consecutive and homogenous population of patients with claudication. From June 2000 to December 2006, 90 external iliac arteries were treated with systematic stenting for atheromatous lesions in 81 consecutive patients with claudication (74 men and 7 women, aged 62+/-12 years). Lesions were classified according to the Trans-Atlantic Intersociety Consensus (TASC). Endovascular treatment was systematically chosen for TASC A (n=40) and B (n=30) patients and patients at high surgical risk for TASC C (n=18) and D (n=2). One hundred and seven stents were placed; they were 37+/-21 mm long with a 7+/-0.6mm diameter. Clinical examination and duplex follow-up were carried out at a minimum of 3 months and at the end of the follow-up. There was a 2.2% complication rate, without any deaths (retroperitoneal hematoma). Mean follow-up was 23 months (with a 13-month median). Primary patency rate was 97% (standard error [SE] 2%) at 1 year, 90% (SE 4.6%) at 2 years, and 84% (SE 6.6%) at 3 years. Secondary patency rate was 98% (SE 1.5%) at 1 year, 93% (SE 3.9%) at 2 years, and 93% (SE 4.5%) at 3 years. Ten restenoses were detected and treated by endovascular techniques (n=6), bypass (n=2), or medication (n=2). At the end of the follow-up, the patients were asymptomatic (n=62) or presented with a moderate (n=17) or severe (n=8) claudication. A patient with hemodialysis was amputated at the metatarsal level. No significant predictive restenosis factor was discovered. However, the C or D TASC classification seemed to favor an earlier restenosis (p=0.06). In conclusion, our study demonstrates that, in a larger population than in the literature, systematic stenting on the external iliac artery gives satisfying results in patients with claudication.

Cost-effectiveness of new cardiac and vascular rehabilitation strategies for patients with coronary artery disease

Objective

Peripheral arterial disease (PAD) often hinders the cardiac rehabilitation program. The aim of this study was evaluating the relative cost-effectiveness of new rehabilitation strategies which include the diagnosis and treatment of PAD in patients with coronary artery disease (CAD) undergoing cardiac rehabilitation.

Data Sources

Best-available evidence was retrieved from literature and combined with primary data from 231 patients.

Methods

We developed a Markov decision model to compare the following treatment strategies: 1. cardiac rehabilitation only; 2. ankle-brachial index (ABI) if cardiac rehabilitation fails followed by diagnostic work-up and revascularization for PAD if needed; 3. ABI prior to cardiac rehabilitation followed by diagnostic work-up and revascularization for PAD if needed. Quality-adjusted-life years (QALYs), life-time costs (US $), incremental cost-effectiveness ratios (ICER), and gain in net health benefits (NHB) in QALY equivalents were calculated. A threshold willingness-to-pay of $75 000 was used.

Results

ABI if cardiac rehabilitation fails was the most favorable strategy with an ICER of $44 251 per QALY gained and an incremental NHB compared to cardiac rehabilitation only of 0.03 QALYs (95% CI: −0.17, 0.29) at a threshold willingness-to-pay of $75 000/QALY. After sensitivity analysis, a combined cardiac and vascular rehabilitation program increased the success rate and would dominate the other two strategies with total lifetime costs of $30 246 a quality-adjusted life expectancy of 3.84 years, and an incremental NHB of 0.06 QALYs (95%CI:−0.24, 0.46) compared to current practice. The results were robust for other different input parameters.

Conclusion

ABI measurement if cardiac rehabilitation fails followed by a diagnostic work-up and revascularization for PAD if needed are potentially cost-effective compared to cardiac rehabilitation only.

Results of endovascular therapy and aortobifemoral grafting for Transatlantic Inter-Society type C and D aortoiliac occlusive disease

OBJECTIVE

The purpose of this study was to compare the outcomes of aortoiliac stenting (AIS) to those of aortobifemoral grafting (ABF) for patients with TransAtlantic Inter-Society Consensus (TASCII) C and D aortoiliac occlusive disease.

METHODS

From 1998 to 2007, 32 patients underwent ABF and 40 patients underwent AIS. Kaplan-Meier estimates for patency were used.

RESULTS

Patients undergoing AIS were older (66.6 years ABF vs 59.2 years AIS; P=.006). The ABF group had simultaneous profundoplasty (n = 8) and femoral-popliteal graft (n =1). Six patients had treatment for concomitant infrainguinal disease at the time of AIS. There was no mortality in either group. Average hospital stay in the ABF group was 7 +/- 2 days and 1 +/- 0.3 days for AIS (P = .0001). Pulmonary complications predominated in the ABF group (13%). Four patients in the AIS group (10%) developed intraprocedural complications. Primary patency at 48 months was 69 +/- .12% for AIS and 93 +/- .07% for ABF (P = .013). There was a significant increase in ankle-brachial indices after revascularization in both groups.

CONCLUSIONS

TASC type C and D lesions can be treated with either ABF or AIS with satisfactory results. Compared with ABF, AIS is associated with decreased primary patency, decreased perioperative morbidity, and shorter hospital stay.

[Critical limb ischemia]

Critical limb ischemia can be divided into acute and chronic forms. All patients suspected of the acute form should be evaluated immediately, as urgent revascularization is usually necessary. Chronic critical limb ischemia is the most complicated type of peripheral artery disease (PAD). Typical for it are pain at rest and necrosis or gangrene. The most important known risk factors are nicotine, hypertension, diabetes, and hyperlipoproteinemia. Patients suffering from PAD run a significantly higher risk of cardiovascular or cerebrovascular events and therefore should be on permanent antithrombotic therapy as secondary prophylaxis. Besides clinical examination and determination of the ankle/brachial index, complementary imaging is mandatory. Here angiography is the gold standard. For therapy surgical and other interventional procedures are available. The decision on individual therapy follows an interdisciplinary approach based on an international consensus (TASC classification).

Current status of heroic limb salvage for critical limb ischemia

The treatment of chronic lower extremity peripheral arterial disease is in a state of flux. During the past decade, vascular surgeons have assumed the responsibility for the endovascular care of patients needing vascular intervention. Once surgeons began performing these procedures, a change in attitude toward angioplasty resulted in an "endovascular explosion" and an overall reassessment of the traditional approaches to critical limb ischemia. Our current method of assessing outcomes is also in a state of flux. The original measure of procedural success, reconstruction patency, has been found to be a poor predictor of both patient palliation and functional success. A shift toward determining more accurate, patient-oriented outcome measures is ongoing. Until then, evidence would suggest that there are patients with such severe medical comorbidities, which include impaired ambulatory ability at presentation, that the benefits of revascularization seem to be insignificant. As our patient population ages and our healthcare system continues to fail financially, economic rationing motivated by lack of evidence-based data to the contrary may dictate that these patients are best served by primary limb amputation.

Quality improvement guidelines for endovascular treatment of iliac artery occlusive disease

Endovascular therapy is the treatment of choice for type A and the preferred treatment for type B lesions. In selective patients, this type of treatment can be applied in type C and even type D lesions. Ipsilateral femoral, contralateral femoral, and brachial approach and both the intraluminal and subintimal space can be used for successful recanalization. The application of stents has improved the immediate hemodynamic and probably long-term clinical results of iliac percutaneous transluminal angioplasty. However, the superiority of primary or direct stenting over selective stenting has not been proven yet. The choice of stent type depends on lesion morphology and location but otherwise there is insufficient evidence to support the use of a particular stent design. There is insufficient evidence to justify routine use of covered stents. All patients should receive antiaggregant therapy following endovascular recanalization of iliac arteries. There is no consensus regarding prophylaxis with antibiotics in iliac recanalization procedures.

Endovascular therapies for peripheral arterial disease: an evidence-based review

Peripheral arterial disease is one manifestation of systemic atherosclerosis. The prevalence of peripheral arterial disease increases with the age of the population. It is important to remember the significant association of coincident coronary artery disease, which is the major cause of mortality in these patients. Remarkable technological advances in the past decade, along with patient preference, have shifted revascularization strategies from traditional open surgical approaches toward lower-morbidity percutaneous endovascular treatments. The availability of stents, more than any other advance, has fueled the growth of catheter-based procedures by improving the safety, durability, and predictability of percutaneous revascularization.

Reduction of Stenosis Due to Intimal Hyperplasia After Stent Supported Angioplasty of Peripheral Arteries by Local Administration of Paclitaxel in Swine

PURPOSE

To assess if local intra-arterial administration of paclitaxel using drug-coated balloons or an admixture of paclitaxel to contrast medium inhibits stenosis after percutanous transluminal angioplasty (PTA) of peripheral arteries in a porcine overstretch model.

METHODS

Neointimal proliferation and stenosis were induced by overstretch and stenting of 40 peripheral arteries in 20 pigs. Paclitaxel was administered locally during PTA using coated balloons (n = 20) or dissolved in contrast medium (n = 10). Conventional balloons and contrast medium were used in a control group (n = 10). Reangiography with quantitative analysis was performed after 5 weeks.

RESULTS

On reangiography diameter stenosis and late lumen loss were significantly reduced by both methods of local drug delivery compared with control group; minimal luminal diameter was significantly larger in the treatment groups.

CONCLUSIONS

Local short-term administration of paclitaxel during PTA of peripheral arteries using balloons or contrast medium as drug carriers reduced stenosis due to intimal hyperplasia.

Progress in the endovascular treatment of intermittent claudication: rationale for changes in the TASC classification

Published in 2000, the TransAtlantic Inter-Societal Consensus (TASC) guidelines contained a new classification system for treatment of peripheral arterial disease. The classification was based upon response to intervention and was independent of technology and techniques. The goal of this system was to indicate the best form of treatment, endovascular (TASC A) or surgical (TASC D), for patients with lower-extremity arterial occlusive disease based upon highest levels of evidence in published reports. Those lesions without strongly supportive evidence, but with a greater likelihood of good response to endovascular (TASC B) or surgery (TASC C), were noted as critical issues requiring additional assessment. It was the intent of the TASC Working Group that this classification be periodically updated. Lesion location, length, calcification, and occlusion have each posed significant challenges to the successful and enduring endovascular treatment of peripheral arterial disease. Since 2000, vascular specialists have systematically addressed these variables with new technology and techniques to improve results. These improvements have been reflected in changes to lesions included in each category of the initial TASC classification system as listed in TASC II. This review provides an evidence-based rationale for these changes.

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.