Aortoiliac Stent Research Articles

Hemodynamic comparison of stent configurations used for aortoiliac occlusive disease

BackgroundEndovascular treatment of aortoiliac occlusive disease entails the use of multiple stents to reconstruct the aortic bifurcation. Different configurations have been applied and geometric variations exist, as quantified in previous work. Other studies concluded that specific stent geometry seems to affect patency. These variations may affect local flow patterns, resulting in different wall shear stress (WSS) and oscillating shear index (OSI). The aim of this study was to compare the effect of different stent configurations on flow perturbations (recirculation and fluid stasis), WSS, and OSI in an in vitro setup. MethodsThree different stent configurations were deployed in transparent silicone models: bare-metal kissing (BMK) stents, covered kissing (CK) stents, and the covered endovascular reconstruction of the aortic bifurcation (CERAB) configuration. Transparent covered stents were created with polyurethane to enable visualization. Models were placed in a circulation setup under physiologic flow conditions. Time-resolved laser particle image velocimetry techniques were used to quantify the flow, and WSS and OSI were calculated. ResultsThe BMK configuration did not show flow disturbances at the inflow section, and WSS values were similar to the control. An area of persistent low flow was observed throughout the cardiac cycle in the area between the anatomic bifurcation and neobifurcation. The CK model showed recirculation zones near the inflow area of the stents with a resulting low average WSS value and high OSI. The proximal inflow of the CERAB configuration did not show flow disturbances, and WSS values were comparable to control. Near the inflow of the limbs, a minor zone of recirculation was observed without changes in WSS values. Flow, WSS, and OSI on the lateral wall of the proximal iliac artery were undisturbed in all models. ConclusionsThe studied aortoiliac stent configurations have distinct locations where flow disturbances occur, and these are related to the radial mismatch. The CERAB configuration is the most unimpaired physiologic reconstruction, whereas BMK and CK stents have their typical zones of flow recirculation.

VS08. Endovascular Aortobiiliac “Bypass” for Juxtarenal Aortobiiliac Occlusive Disease

This video shows endovascular treatment of juxtarenal aortoiliac occlusive disease using covered stents placed in kissing stent fashion. The last three videos show this patient 5 years later with patent aortoiliac stents.

Outcomes of Endurant stent graft in narrow aortic bifurcation

The purpose of this study was to compare the outcomes obtained with Endurant stent graft in the early and midterm period in the treatment of patients with narrow aortic bifurcation vs patients with standard aortic bifurcation. Data were prospectively collected from 817 patients with abdominal aortic aneurysm treated between November 2007 and August 2014 with the Endurant stent graft at our center. There were 87 patients (10.6%) with a narrow aortic bifurcation (≤20mm; NA group). The remaining 730 patients (89.4%) had a standard aortic bifurcation (SA group). Early and estimated 3-year outcomes were evaluated in these patients in terms of survival, freedom from any device-related reinterventions, and freedom from graft thrombosis. Univariate and multivariate analyses in the NA group were performed to detect possible predictors for poor outcomes. The two groups were similar in terms of demographics, preoperative diagnostic assessment, and intraoperative data. In 211 of 817 patients (25.8%), an adjunctive iliac limb stenting by balloon-expanding stents was performed. Overall, 41 patients in the NA group (47.1%) underwent iliac limb stenting, whereas an iliac stent was implanted in just 170 patients (23.3%) in the SA group (P< .001). The mean follow-up was 16.3months (range, 1-73 months). The estimated 3-year survival rate was similar between the two groups (87.2% in the NA group vs 80.8% in the SA group; P= .84). Furthermore, the estimated freedom from any device-related reinterventions was 92.9% in the NA group and 85.5% in the SA group (P= .1). Finally, the estimated 3-year freedom from graft thrombosis was 96.9% in the NA group and 94.8% in the SA group (P= .79). In the NA group at univariate and multivariate analyses, none of the examined preoperative or intraoperative factors were independent predictors of poor outcomes. Use of bifurcated Endurant stent graft, combined in almost half of the patients with narrow aortic bifurcation with additional aortoiliac stent placement, is feasible and safe. Early and midterm outcomes are similar to those obtained in non-narrow aortic bifurcation.

Comparison of Midterm Outcomes between Surgical Treatment and Endovascular Reconstruction for Chronic Infrarenal Aortoiliac Occlusion

PurposeTo compare the midterm results of aortoiliac stent (AIS) placement with those of surgical treatment in patients with chronic infrarenal aortoiliac occlusion. Materials and MethodsMidterm outcomes in patients treated at a single center from 2005 to 2010 were retrospectively reviewed. Correlations between baseline clinical factors and midterm outcomes were assessed. ResultsThe technical success rate was significantly lower in the AIS group than in the surgery group (83.3% vs 100%; P = .016). Of 68 technically successfully treated patients, 33 underwent surgical revascularization and 35 received AIS placement. There were no significant differences in patient demographics, Rutherford classification, cardiovascular risk factors, and 30-day mortality rates. Surgically treated patients had a longer average postoperative hospital stay (P = .001) and higher rates of postoperative complications, including respiratory failure (P = .010), transient renal dysfunction (P = .002), and multiple organ dysfunction (P = .023). Mean ankle-brachial index increased significantly in both groups (P < .001), but to the same extent. The primary 1-, 3-, and 5-year patency rates were 93.6%, 90.2%, and 90.2%, respectively, in the surgery group, and 91.4%, 81.8%, and 64.2%, respectively, in the AIS group (P = .054). No differences were observed in survival rate (P = .945), limb salvage (P = .860), or secondary patency (P = .916). ConclusionsAIS for chronic infrarenal aortoiliac occlusion is associated with a shorter hospital stay and lower postoperative morbidity rates. Although midterm primary patency rate was lower than for traditional open surgery, AIS appears to be a safe, minimally invasive, and reliable procedure for patients with chronic infrarenal aortoiliac occlusion.

Endovascular management of total juxtarenal aortic occlusive disease in high-risk patients: technical considerations and clinical outcome.

To report our single-center experience in the endovascular treatment of juxtarenal aorto-iliac occlusions. Between December 2008 and December 2012, 13 patients with total juxtarenal aorto-iliac occlusion, considered at high risk for open revascularization, were treated by endovascular means at our Department. Inclusion criteria were severe intermittent claudication, rest pain and distal tissue loss. Antegrade recanalization from percutaneous brachial access and retrograde angioplasty and stenting from percutaneous or surgical femoral accesses were performed. The renal arteries (RAs) were protected using filters or balloons. Aorto-iliac bare-metal stents were deployed in all patients. No death was registered. Technical success was 100%. In 11 patients (84.6%) the Ankle-Brachial Index increased to 0.9-1. Renal arteries were involved in 7 cases (53.8%): 3 chimney stent grafts deployment, 2 aorto-iliac stent fenestrations and 2 aorto-iliac stents placement above the renal arteries without renal function impairment. Complication rate was 38.5%: 2 cases of thrombus dislodgement into the RAs, 1 distal artery embolization, 1 common iliac artery rupture and 1 pseudo-aneurysm. All complications were treated percutaneously, except for the distal embolization treated surgically. The patient with iliac artery rupture underwent acute renal insufficiency requiring temporary dialysis after hemorrhagic shock because of retroperitoneal hematoma. Mean follow-up was 18 months (range 6-30 months). The primary and secondary patency was respectively 92.3% and 100%. Endovascular recanalization of juxtarenal aorto-iliac occlusion in selected patients is feasible and safe, with good early and mid-term results and should be considered in high risk patients.

Reinfection after resection and revascularization of infected infrarenal abdominal aortic grafts

Despite advances in perioperative care, long-term and amputation-free survival rates are poor after resection of infected abdominal aortic grafts. We reviewed our cases to determine the rate of reinfection and risk factors for mortality and limb loss. We reviewed cases with infrarenal aortic graft infection from 1999 to 2013. Cases requiring graft excision were included for analysis. Thoracic and thoracoabdominal aortic grafts were excluded. Reconstruction types included both extra-anatomic and in situ grafts. Patient comorbidities, surgical outcomes, and known reinfection rates were assessed. Univariate and Kaplan-Meier analysis were performed. Twenty-eight patients had resection of infected infrarenal abdominal aortic grafts during the study period. Most patients (26/28; 93%) had infected aortoiliac or aortofemoral prosthetic bypass grafts, but two of 28 patients had infected endovascular aortoiliac stent grafts. The median age was 69 years (range, 46-86 years), with 68% men and 32% women. Aortoenteric fistulae or graft-enteric erosions were noted in 12 of 28 (43%) patients at operation. There were 79% of patients who had in situ reconstruction, including 4 (14%) with polyester, 1 (4%) with polytetrafluoroethylene, 3 (11%) with cadaveric homograft, 3 (11%) with composite grafts, and 11 (39%) with native femoropopliteal vein grafts. Five (18%) patients had extra-anatomic bypass and one had excision without revascularization. In-hospital mortality after initial graft excision and revascularization occurred in two (7%) patients. Seven (25%) patients had evidence of reinfection after a median of 20 months, of whom five underwent reintervention with two additional in-hospital deaths. All in-hospital deaths occurred in patients with graft-enteric contamination. Overall limb salvage and survival at a mean follow-up of 2.5 years were 82% and 46%, respectively, and did not differ among revascularization types (P = .85 and .74). One-year amputation-free survival was 47% overall. Three patients with native femoropopliteal vein graft repair required amputation in follow-up. Diabetes was the only observed risk factor for amputation (P = .05). Risks for mortality included history of cerebrovascular disease (P = .05) and shock on presentation (P = .04). No other comorbid condition, type of revascularization, or perioperative complication was associated with limb loss or mortality on univariate analysis. Revascularization after excision of infected abdominal aortic grafts can be done with acceptable in-hospital morbidity and mortality. Reinfection is problematic, regardless of revascularization conduit, and is associated with limb loss and death. New and aggressive local anti-infective strategies are warranted.

Endovascular treatment of isolated iliac artery aneurysms using a custom-made stent graft with proximal barb fixation: early outcome

Current endovascular treatments for isolated iliac artery aneurysms (IIAAs) include the use of aortoiliac stent grafts with coverage of the distal aorta or stent grafts confined to the iliac artery without active proximal fixation. We report our experience in the use of custom-made Cook Zenith(TM) iliac limb stent grafts with proximal barb fixation. Patients treated from July 2009 to February 2011 were included. All imaging and patient records were assessed for perioperative and early outcomes. Nine IIAAs (seven patients) were treated. The mean patient age was 80 years (range 58-91 years). The mean aneurysm size was 48 mm (35-80 mm), and the mean length of the proximal landing zone (PLZ) was 29 mm (10-50 mm). The distal landing zone was in the external iliac artery after coil embolization of the internal iliac artery. The Mean diameter of the PLZ was 21 mm (20-24 mm). Technical success was achieved in eight cases. Perioperative complications included reoperation in one patient for groin bleeding and ischemia. On follow-up (mean 12 months, range 1-26), all aneurysms were successfully excluded from the circulation and there was no stent graft migration or thrombosis. Use of custom-made stent grafts with proximal barb fixation in treatment of IIAAs is a feasible option which may reduce the risk of migration when compared with stent grafts with lack of proximal fixation.

A Case of Complex Restenosis of Aortoiliac Stent Mimicking Downward Stent Migration

We present the case of aortoiliac stent restenosis which was caused by 13 years’ of neointimal progression within and at the edge of the aortoiliac stent at the iliac bifurcation. A 74 year-old man presented with vertigo. We planned 4-vessel cerebral angiography through the right common femoral artery to evaluate his carotid artery but failed due to the catheter jam against the struts of the previously deployed aortoiliac stent. Retrograde sheath angiography through the right femoral artery indicated that the previously implanted stent seemed to have migrated in a downward direction and be embedded in the internal iliac artery. While comparing with the previous angiograms, we found that the implanted stent did not migrate downwardly but was separated from the external iliac artery by newly formed septum of neointimal hyperplasia. We successfully reopened the stenosis using the contralateral approach after widening the struts of the previously deployed T-stents.

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.

Aortic rupture due to pneumococcal infection in aortoiliac stents

We report a rare case of pneumococcal aortitis secondary to endovascular bare-metal stent infection. The patient was a 70-year-old man presenting with back pain 1 year after aortoiliac implantation of bare-metal kissing stents. Final diagnosis was microbial aortitis due to Streptococcus pneumoniae involving the stents that resulted in a contained aortic rupture requiring urgent surgical treatment. Emergency extra-anatomic revascularization, excision of the infected tissues, and appropriate antibiotic therapy led to a favorable outcome. A high index of suspicion is required in such a situation because the mortality rate is very high in the absence of appropriate treatment.

Endovascular Management of Isolated Iliac Artery Aneurysms: Retrospective Analysis

Purpose: To evaluate the early and midterm results of the endovascular treatment of patients that had an isolated iliac artery aneurysm (IIAA). Materials and Methods: From February 2004 to April 2009, 15 patients (9 men, 6 women) with IIAA underwent endovascular treatment such as stent graft insertion or embolization. Computed tomography angiography (CTA) was performed for the diagnosis of an aneurysm and for a follow-up after treatment. The medial records and CTAs were retrospectively reviewed for analysis of the symptoms, past history of disease, combined disease, anatomical morphology of aneurysm, and complications. Results: The mean aneurysm diameter was 36.9 mm (range: 20 mm - 80 mm). The aneurysm sites included the common iliac in 8 patients, internal iliac in 5 patients, and a combined common and internal iliac in 2 patients. Tubular stent grafts or bifurcated aorto-iliac stent grafts were used singly or mixed. The internal iliac arteries of 11 patients were embolized by microcoils or by Amplatz vascular plugs or by both methods. The technical success achieved for embolization was 93.3% (n=14). The mean follow-up period was 125.5 days (range: 7 - 701 days). The stent graft patency rate was 100%. On follow- up CTA, 1 patient experienced a type I endoleak, whereas 1 patient experienced a type II endoleak. Conclusion: The endovascular treatment of IIAA shows positive early and mid-term results. The procedure is a safe, minimally invasive, and has a low complication rate.

Kissing Stent Reconstruction of the Aortoiliac Bifurcation

Kissing stent reconstruction of the aortoiliac bifurcation is a widely used technique for the management of aortoiliac occlusive disease involving the aortic bifurcation or proximal common iliac arteries. New advances in delivery systems and stent design have enabled better anatomic results with kissing stenting. Long-term patency is generally excellent, although several factors may adversely affect patency and should be taken into account when devising the stenting configuration and selecting the device to be used. Geometric variables related to individual aortic anatomy and disease pattern (patient dependent) and stenting configuration (operator dependent) may have an impact on long-term patency. Kissing stent aortoiliac reconstruction is effective and durable, even with complex aortoiliac disease and long-segment occlusions. In our experience, TASC (TransAtlantic Inter-Society Consensus) C and D class disease is not necessarily a contraindication to aortoiliac stent reconstruction, especially in poor operative risk patients. Most restenoses are amenable to endovascular treatment, with excellent long-term assisted patency.

Endovascular Treatment of a Primary Aortoduodenal Fistula: 2-Year Follow-Up of a Case Report

The purpose is to evaluate the role of endovascular management for primary aortoduodenal fistula in poor surgical risk patients. A 70-year-old-man was admitted at the emergency room of our hospital with recurrent upper-gastrointestinal bleeding. A diagnostic workup was suggestive of a primary aortoduodenal fistula caused by erosion of an infrarenal abdominal aortic aneurysm. Intractable cardiac arrhythmia, recurrent hemorrhage, and poor patient condition were compatible with an exceedingly high surgical risk. The fistula was successfully treated, and gastrointestinal bleeding was eliminated with placement of a Lifepath endoluminal aortoiliac stent graft. At the 21-month follow-up, the patient was not presenting with symptoms and signs of graft infection, and radiologic studies confirmed decreasing aneurysm size without associated signs of local sepsis. Endovascular stent grafts can efficiently arrest massive exsanguination in critically ill patients with primary aortoenteric fistula. The risk of graft infection remains the most serious problem associated with this approach.

Quality of Life and Exercise Performance after Aortoiliac Stent Placement for Claudication

To determine the effect of aortoiliac stent placement on walking ability and health-related quality of life (QOL) for elderly individuals with moderate to severe intermittent claudication. A prospective single-center study was performed in 35 consecutive patients (46 symptomatic limbs) with intermittent claudication and aortoiliac insufficiency (mean age+/-SD, 61.1 years+/-9.5). Baseline and follow-up data to 12 months included clinical status, ankle-brachial index (ABI), exercise performance according to a standardized treadmill exercise protocol, and self-reported health-related QOL according to the Walking Impairment Questionnaire (WIQ) and the Short Form 36 (SF-36). Comparing baseline with 12-month data, mean ABI significantly improved from 0.64+/-0.15 to 0.89+/-0.19 (P<.01). Similarly, mean initial claudication duration improved from 1.7 minutes+/-1.0 to 4.7 minutes+/-3.3 and maximum walking duration on the treadmill test improved from a mean of 3.3 minutes+/-1.8 to 8.7 minutes+/-4.4. All WIQ subscales showed significant improvement, and the SF-36 physical component scale as well as subscales of physical functioning, bodily pain, role physical, and vitality showed significant improvement. There was no 30-day mortality. Complications in the perioperative period that required treatment were observed in three patients (9%), but surgery was not required for any complications. Importantly, urgent or emergent surgery was not required for any complication and no permanent disability related to complications occurred. A high technical success rate (97%) and low complication rate were observed. Exercise performance and health-related QOL results improved significantly after stent placement. Revascularization with stent placement should be strongly considered in addition to conservative management for moderate to severe claudication with aortoiliac obstruction. A randomized clinical trial would be needed to gauge the relative effectiveness of stent implantation and conservative therapy.

A new technique for embolisation of the hypogastric artery

Embolisation of hypogastric arteries prior to the placement of aortoiliac stents to treat aneurysms is not always possible. To present a new technique for the embolisation of ‘hostile’ hypogastric arteries which is performed at the same time as the placement of the aortoiliac stent. This procedure was used to treat six patients with aortoiliac (4) and iliac (2) aneurysms. Follow-up was carried out by computerised tomography (CT) in the first week and at one, three and six months. Endovascular technique: a) Placement of a coudé catheter near the hypogastric artery or in the sac; the stent is introduced through the same arteriotomy; b) The stent is deployed and, before ballooning it, the coils are released; c) 100 to 200 cm 3 of serum are injected into the sac to wash the coils towards the ostium of the hypogastric artery; d) Withdrawal of the catheter and ballooning of the distal end of the stent. The CT scan showed thrombosis of the iliac aneurysm in the first week in four of the patients and at one month in the others. There were no signs of endoleaks or movements of the coils inside the sac. Buttock claudication was noted in four of the six patients. There were no cases of colic ischaemia. This original method of embolisation has proved to be effective and safe with regard to its capacity to thrombose arteries that are potential producers of type II endoleaks, since it prevents unwanted movements of the coils.

Preclinical Evaluation of Drug-Eluting Stents for Peripheral Applications

Drug-eluting stents implanted in the coronary arteries substantially improve long-term outcomes for restenosis. The utility of the stents in peripheral atherosclerosis is under evaluation. Drug-eluting stent evaluation with coronary arteries appears to be an excellent method for evaluating human safety end points. Predicting clinical efficacy remains unclear, however. Because drug-eluting stents are undergoing development for human peripheral arteries, safety and efficacy questions arise in much the same context as they did for the coronary arteries. As they did with the coronary arteries, the clinical, scientific, regulatory, and commercial communities are seeking acceptable criteria for peripheral device evaluation. Substantial differences in stent requirements and biological effects for bare metal peripheral stents depend on implant site. Different anatomic locations under evaluation include femoral, renal, and neurologic arterial stents, and other peripheral applications such as outflow veins of dialysis arteriovenous fistulae are being evaluated. Peripheral in-stent restenosis is less of a problem in carotid and aortoiliac stents and in iliac veins and in the cavae. In general, the benefit:risk ratio for drug-eluting stents may be less for peripheral stents. It is for this reason that peripheral stent performance should be evaluated carefully. This document presents an integrated recommendation set for evaluating drug-eluting stents in peripheral vessels with preclinical models. The recommendations encompass study design, experimental performance, and histopathologic evaluations and emphasize the need to evaluate safety and efficacy at multiple points in time. The present document is a consensus of clinical, academic, and commercial groups—all experts in the evaluation of preclinical investigational or interventional devices. Because preclinical peripheral studies are less well understood than are coronary models, the recommendations do not prescribe a single method for device evaluation; they instead provide broad suggestions for evaluation. Peripheral vascular knowledge will increase as correlations of preclinical with clinical data become available. Future versions of this …

Aortoiliac Stent Graft Infection: Current Problems and Management

Aortic stent graft infection is uncommon. Most cases have been described anecdotaly in single-case reports. After observing one case in our experience, we decided to review the literature and contact centers performing endovascular aortic repair to determine the frequency, risk factors, and current treatment of stent graft infection. The literature was reviewed and the authors of identified articles were contacted for further information. In addition, 40 centers specializing in endovascular treatment were contacted by means a dedicated questionnaire. A total of 65 aortic stent graft infections were identified, including 43 reported cases and 22 previously unpublished cases that were observed at specialized centers. Stent grafts were implanted in the aorta in 50 cases and in the iliac artery in 15 cases. The frequency of infection was 0.43%. The gender ratio was 4:1 (M:F). Twenty-three percent of patients had immunodeficiency factors. Placement was performed in an interventional radiology suite in 62.5% of cases and in a sterile operating theater in 37.5%. Also, 35.5% of patients underwent other vascular procedures during the course of study and 29.2% stent grafts benefited from adjuvant endovascular procedures. Infection was classified as low grade in 35.4% of patients and high grade in 64.6%. Thirty-one percent of infections were associated with aortoenteric fistula. The offending microorganism was Staphylococcus aureus in 54.5% of cases. Treatment was conservative in 18% of cases and surgical in 82%. Surgical treatment consisted of stent graft removal followed by either extraanatomical bypass (59.5%) or in situ prosthetic reconstruction (40.5%). Mortality was 18% overall, 36.4% after conservative treatment and 14% after surgical treatment ( p = 0.083). Mortality was 16% after surgical treatment with extraanatomical bypass vs. 5.8% surgical treatment with in situ reconstruction. From these results we conclude that stent graft infection is an uncommon occurrence associated with poorly defined risk factors. Surgical treatment with complete excision of the infected stent graft followed by in situ reconstruction provides the best outcome. Establishment of a multicenter register to record such complications is needed to confirm the findings of this study.

Effect of ethnicity on access and device complications during endovascular aneurysm repair

Introduction There are no published reports on the association between ethnicity and outcome after aortoiliac stent grafting to treat aneurismal disease. Because Hawaii is a state with an ethnically diverse population, we conducted a retrospective study to examine this potential association. We hypothesized that individuals of Asian ancestry may have higher complication rates after endovascular repair compared with non-Asians. Methods All endovascular devices placed to treat aneurysm disease from 1996 to 2003 were evaluated in two institutions. The association between ethnicity and access-related and device-related complications, both periprocedural and delayed, was examined with logistic regression analysis. Results Ninety-two aortoiliac endografts were placed during the study period, including 87 in patients with abdominal aortic aneurysms with or without iliac aneurysm disease, and five patients with isolated iliac artery aneurysms. Forty-four percent of patients were categorized as Asian, 39% as white, 16% as Pacific Islander, and 1% as African American. Access-related and device-related complications (ADRCs) occurred in 11 of 92 (12%) of these patients. The following parameters were significantly associated with ADRCs: Asian ethnicity ( P =.015), age greater than 80 years ( P = .02), and external iliac diameter smaller than 7.5 mm ( P =.01). Asian patients were more likely to have experienced ADRCs than were non-Asian patients (odds ratio, 7.3; 95% confidence interval, 1.5-35.8; P = .015). Asians also had smaller external iliac artery diameters ( P = .0003) and more tortuous iliac arteries ( P = .03) compared with non-Asians. After adjusting for iliac artery diameter and tortuosity, the association between Asian ethnicity and ARDCs became nonsignificant ( P = .074), which suggests that the association between race and complications may be at least in part due to small and tortuous iliac arteries. There was no association between age, gender, or ethnicity and postoperative detection of endoleak. Conclusion Our data indicate that individuals of Asian ancestry are far more likely to experience adverse access-related and device-related complications after aortoiliac stent grafting than are non-Asians. We found that this association is at least partly attributable to the smaller and more tortuous iliac arteries in persons of Asian ancestry.

Late Complication of Aortoiliac Stent Placement— Atheroembolization of the Lower Extremities

Background. Atheroembolization following aortoiliac stent placement is uncommon. The purpose of this study was to examine the management and risk factors of lower extremity atheroembolization following aortoiliac stent placement for occlusive disease.Materials and methods. From March 1993 to February 2001, the hospital records of all patients who developed thromboembolic events following aortoiliac stent placement were reviewed. Risk factor analysis was performed by comparing with the control group, which consisted of 493 patients treated with aortoiliac stents during the study period who did not develop atheroembolic complications. Patients with cardiac etiologies or aortic aneurysms as the source of embolization as well as those who developed acute embolization following stent deployment (<30 days) were excluded.Results. Atheroembolization occurred in eight patients (12 iliac artery stents and 1 aortic stent) at intervals ranging from 9 to 43 months (mean 22 months) following aortoiliac stent placement. Arteriography in all patients implicated the stented artery as the source of atheroembolism. Five corrective operations (two aorto-bifemoral bypasses, one ileofemoral bypass, and two aortoiliac endarterectomies) along with two concomitant femoropopliteal thrombectomies were performed successfully in five patients. The remaining three patients were treated with either thrombolysis and/or additional stent placement, which resulted in either iliac occlusion or recurrent embolic symptoms (P < 0.05). All 3 patients subsequently underwent bypass procedures (one ileofemoral and two femorofemoral bypasses). There was no perioperative mortality. During a mean follow-up of 16 months (range 3 to 45 months), two patients required minor amputations, whereas one required major leg amputation. No further episodes of atheroembolism occurred in the involved limbs following surgical bypass procedures. Risk factor analysis failed to identify potential variables that correlated with atheroembolism following aortoiliac stent placement.Conclusion. Patients with atheromatous embolization following aortoiliac stent placement should be evaluated aggressively. The treatment of choice is surgical correction or bypass with exclusion of the offending embolic source. Although intra-arterial stent placement in the atheroembolic stented iliac artery is feasible, it may provide a less durable result.

Duplex Follow-up of Aorto-iliac Stents

Objectives to assess the feasibility of duplex follow up of aorto-iliac stents. Material and methods in addition to standard clinical and ankle/brachial pressure assessment, 75 patients undergoing aorto-iliac stenting for atherosclerotic disease were prospectively followed up with duplex ultrasound at 3 monthly interval up to 1 year and then annually. We attempted to directly visualise the stents wherever possible using standard 2D imaging, standard and power Doppler, as well as spectral Doppler. Patients had an angiogram at 12 months or sooner if a problem was identified on the duplex scan. Results mean follow up was 14 months (2–36). Complete visualisation of the pelvic arterial tree was achieved in 94% of scans. All patients had at least one satisfactory scan. Duplex detected 30 lesions in 23 patients. Twenty-seven lesions were confirmed at angiography. There were two false positives. Overall sensitivity, specificity and accuracy were 100%, 93% and 96% for patient undergoing angiography. Conclusion duplex ultrasound follow up is feasible in the majority of patients.