Limb Occlusion after Endovascular Repair of Abdominal Aortic Aneurysms with Supported Endografts

Predictive Factors for Iliac Limb Occlusions After Endovascular Abdominal Aneurysm Repair: Determined from Aortoiliac Anatomy, Endovascular Procedures, and Aneurysmal Remodeling

Purpose

Iliac limb occlusion (ILO) is a serious complication of endovascular abdominal aneurysm repair (EVAR). This study aimed to identify predictive factors for ILO derived from aortoiliac morphology, endovascular procedure-related parameters, and aneurysmal remodeling characteristics.

Patients and Methods

Patient demographics, pre-EVAR anatomical characteristics of the aneurysm, endovascular procedure details, and post-EVAR aneurysmal remodeling outcomes were analyzed and compared using univariate analysis. Statistically significant factors were subsequently subjected to Cox regression and Kaplan-Meier analyses.

Results

Between January 2013 and April 2022, 66 patients were included in this study. Fourteen patients presented with ILO and were compared with 52 control patients with patent endograft limb over at least 1-year of follow-up. The tortuosity indices of the common iliac artery (CIA) and endograft iliac limb to vessel oversizing were significantly larger in the ILO group than in the patent endograft limb group. The CIA index of tortuosity ≥1.08, and endograft iliac limb to vessel oversizing ≥18.8% were independent predictors for ILO. During the follow-up of all patients, the proximal aortic neck and CIA diameters increased, aneurysm sac diameter decreased, and aortic neck and aortic length increased. The aortoiliac length increased over time in patients with patent endograft limb but not in patients with ILO. A change in the lowest renal artery-left iliac bifurcation distance ≦0.07 mm increased the risk of ILO.

Conclusion

ILO is predisposed to occur when the CIA index of tortuosity ≥1.08 and endograft iliac limb to vessel oversizing ≥18.8% are present. Significant aortoiliac remodeling, including proximal aortic neck dilatation, neck straightening, aneurysmal sac regression, iliac artery enlargement, and aortic lengthening, occurs after EVAR. Aortoiliac elongation was observed in patients with patent endograft limb, but not in patients with ILO. ILO was associated with a change in the lowest renal artery-left iliac bifurcation from the postoperative measurements ≦ 0.07 mm.

Sequential Graft Limb Occlusion Following Endovascular Aneurysm Repair: A Case Report and Literature Review

Limb graft occlusion (LGO) is a common complication that can occur after endovascular aneurysm repair (EVAR). There are many factors that can contribute to LGO, including patient-related variables, device-related considerations, and factors associated with the procedural technique. Patients with LGO may exhibit no symptoms, have intermittent claudication, or suffer from acute limb ischemia. In this manuscript, we present a case of a 64-year-old male who experienced sequential LGOs after EVAR accompanied by a comprehensive review of the pertinent literature.

Stentgraft Limb Occlusion After Endovascular Aneurysm Repair: Incidence and Risk Factors

INTRODUCTION

Stentgraft limb occlusion (SLO) is a potential complication of endovascular aneurysm repair (EVAR). The purposes of this single centre study are to report the incidence of SLO after EVAR and to detect possible risk factors.

METHODS

All patients who underwent EVAR between June 2001 and February 2020 were included in this retrospective study. Demographic data, cardiovascular risk factors, aneurysm characteristics, arterial anatomy, repair strategy, systemic and stentgraft-related complications, and in-hospital and late mortality were collected. Routine follow-up included duplex examination and/or CT angiography at 3 months, 12 months and annually thereafter. Logistic regression analysis was performed to detect predictors for SLO.

RESULTS

A total of 221 patients (425 stentgraft limbs) were included; of whom 11 patients (5.0%) occluded. Median time to occlusion was 3.3 months and most of the patients presented ischemic signs. Two risk factors for SLO could be identified: symptomatic aneurysm (P .015, odds ratio 4.62, 95% confidence interval 1.35-15.86) and length of the infrarenal abdominal aortic aneurysm (AAA) (P .021, odds ratio 1.31, 95% confidence interval 1.04 - 1.64).

CONCLUSION

The incidence of SLO after EVAR is low, and most occlusions occur within the first year. Predictors for SLO are the symptomatic aneurysm and the length of the infrarenal AAA. Further research is necessary to pool all predictors and to assess the clinical impact of different follow-up strategies for high-vs low-risk patients.

Aneurysm Sac Shrinkage After EVAR Can Lead to Complications: A Case Report of Complete Endograft Thrombosis Due to Kinking

BACKGROUND

Bilateral limb occlusion after endovascular repair of abdominal aortic aneurysms (EVAR) is an uncommon entity. The relationship between graft kinking and unilateral limb occlusion is widely described in the literature. Our aim is to report a case of complete endograft thrombosis due to bilateral limb kinking secondary to aneurysm sac shrinkage, treated by endovascular means.

CASE REPORT

A 67 year-old male with history of EVAR with an Incraft® endograft (Cordis, Bridgewater, NJ, USA) four years before, presented at the emergency department with disabling claudication of the right lower extremity and a better tolerated 10-month left extremity claudication. Complete endograft thrombosis with bilateral limb kinking and a remarkable reduction of the aneurysm sac was observed in the computed tomography angiography. An endovascular repair was performed, through bilateral open femoral access and with angiographic control through percutaneous left brachial access. Bilateral recanalization was achieved and the endograft was re-lined with two 10x150 mm Viabahn (WL Gore & Ass., Flagstaff, AZ, USA). Both sides were extended with a 11 × 50 mm Viabahn (WL Gore & Ass., Flagstaff, AZ, USA). The final angiographic control showed bilateral patency with no residual stenosis and the patient recovered distal pulses. Follow-up showed complete patency and no complications at 17 months.

CONCLUSIONS

Bilateral limb occlusion is a rare complication with technically challenging treatment options. Aneurysm sac shrinkage can affect the endograft configuration, leading to limb distortion and occasionally to bilateral limb occlusion after EVAR. Special attention should be put on imaging follow-up to detect these complications before occlusion occurs.

Penumbra Indigo Percutaneous Aspiration Thrombectomy System in the treatment of Aortic Endograft Iliac Limb Occlusion: Results from an Italian Multicentre Registry

OBJECTIVE

This study aimed to evaluate the safety and effectiveness of the Penumbra Indigo percutaneous aspiration thrombectomy (PAT) system in the clinical presentation of iliac limb occlusion (ILO) after endovascular aortic repair (EVAR).

METHODS

A retrospective, observational, multicentre study conducted in eight Italian vascular centres. Consecutive patients presenting with ILO after EVAR were eligible. To assess vessel revascularisation, Thrombo-aspiration In Peripheral Ischaemia (TIPI) classification (score 0-3) was used at presentation (t1), after PAT (t2), and after adjunctive procedures (t3). Successful revascularisation was considered TIPI 2-3 (near complete or complete). Primary intra-operative outcomes were technical success (TS) of Indigo PAT and combined TS of PAT associated with adjunctive procedures when needed. Primary follow up outcomes were safety and effectiveness at one, six, and 12 months.

RESULTS

From September 2019 to December 2021, there were 48 ILO and 17 patients (35%) [median age 75 years, IQR 71, 83 years; male, 14 (82%); urgent, 8 (47%)] were treated and enrolled. The median time after primary EVAR was 24 months (IQR 0, 42 months). The median clot age from ILO diagnosis to PAT was three days (IQR 1, 12 days). Ten patients (59%) presented with limb threatening ischaemia. At t1, TIPI 0 and 1 was present in 13 (76%) and four (24%) cases, respectively. At t2, primary TS (TIPI 2-3) was achieved in 14 cases (82%) after Indigo PAT (p < .001). Fifteen patients (88%) required adjunctive procedures (14 re-linings, one surgical patch angioplasty). At t3, combined TS was achieved in 16 cases (94%). Intra-operative complication included one (6%) distal embolisation, treated successfully. The 30 day mortality was one case (6%) due to pneumonia. At one, six, and 12 months, clinical success was 100% without ILO recurrence. The median follow up was 23 months (IQR 11, 41 months): at 18 months, survival and freedom from re-intervention were 91 ± 8% and 90 ± 9%, respectively.

CONCLUSION

This study reports for the first time the efficacy and safety of Penumbra Indigo PAT for ILO after EVAR, with promising technical and clinical success up to one year.

The influence of narrow aortic bifurcation on limb graft patency: a two-center retrospective study

BACKGROUND

Narrow aortic bifurcation (NAB) has been considered as a potential risk factor for graft limb thrombosis after endovascular aortic repair (EVAR). The aim of this study was to compare mid- and long-term outcome of EVAR in patients with NAB and standard aortic bifurcation (SAB).

METHODS

Data from patients receiving EVAR were prospectively collected and retrospectively analyzed. In case of angiographic limb stenosis (>50%), additional stenting was performed. Patients with a NAB (≤20mm) were included in the NAB group, the remaining patients in the SAB group. Primary endpoints were limb thrombosis rate and technical success.

RESULTS

A total of 902 patients were included; 18.3% (N.=165/902) in the NAB and 81.7% (N.=737/902) in the SAB group. Mean follow-up time was 43 months (range 0-198 months). Bilateral stenting of the aortic bifurcation was performed in 2.7% (N.=27/902), 8.5% (N.=14/165) in the NAB and 1.4% (N.=10/737) in the SAB group (P=0.001). Limb thrombosis was found in 2.8% (N.=25/902), 3.6% (N.=6/165) in the NAB and 2.6% (N.=19/737) in the SAB group (P=0.55). Technical success was 97.8%, 98.8% in the NAB and 97.6% in the SAB group (P=0.33). Device related reintervention rate was 16% (N.=144/902), 15.2% in the NAB and 16.1% in the SAB group (P=0.75).

CONCLUSIONS

Standard EVAR could safely be performed in patients with NAB (≤20mm) when a low threshold for additional stenting was applied. This resulted in no significant higher incidence of limb thrombosis. Additional stent deployment did not increase the complication rate.

Incidence and predictive factors for endograft limb patency of the Fenestrated Anaconda™ endograft used for complex endovascular aneurysm repair

OBJECTIVE

To describe the incidence, risk factors and outcomes of treatment for limb occlusion in patients treated for complex (thoraco-)abdominal aortic aneurysms (AAA) with the Fenestrated Anaconda™.

METHODS

Between June 2010 and May 2018, 335 patients underwent elective fenestrated aortic aneurysm repair in 11 participating centers using the Fenestrated Anaconda™ with a median follow-up of 14.3 months (IQR 27.4). The primary outcome measure was freedom-from-limb-occlusion. Secondary outcome measures were freedom-from-limb-related-reintervention, secondary patency, and risk factors associated with limb occlusion.

RESULTS

Thirty (9.0%) patients presented with limb occlusion during follow-up with freedom-from-limb-occlusion of 98.5%, 91.2%, and 81.7% at 30-days, 1 and 5 years, respectively. In 87% of cases, no obvious cause for limb occlusion was documented. Primary occlusion occurred within 30-days in 36.7% and within 1 year in 80.0%. Twenty-three (6.9%) patients underwent an occlusion-related reintervention; seven (23.3%) patients were treated conservatively. Freedom-from-limb-occlusion-related-reintervention at 30-days, one and five years was 97.8%, 93.2% and 88.6%, respectively. Secondary patency was 91.3% after 1-month and 86.2% after 1 and 5 years, respectively. Female sex (OR 3.27 - 95% CI 1.28 to 8.34, P = .01) was a statistically significant predictor for limb occlusion. A higher percentage of thrombus in the aneurysm sac appeared to be protective for limb occlusion (0% compared to <25%: OR 0.22 - 95% CI 0.07 to 0.63, P = .01; 0% compared to 25-50%: OR 0.20 - 95% CI 0.07 to 0.57, P = .00 and 0% compared to >50%: OR 0.08 - 95% CI 0.02 to 0.38, P = .00), as did iliac angulation (OR 0.99 - 95% CI 0.98 to 1.00, P = .04).

CONCLUSION

Limb occlusion remains a significant impediment of endograft durability in patients treated with the Fenestrated Anaconda™, especially in female patients. Controversially, a high aneurysmal thrombus load and a high degree of iliac angulation appeared to be protective for limb occlusion, for which no obvious cause could be identified.

Endovascular recanalization and remodeling of abdominal aorta stent graft chronic total occlusion after failed extra-anatomic bypass surgery

OBJECTIVES

Chronic total occlusion (CTO) of the EVAR graft is a rare and serious complication. Traditionally, surgical intervention with prosthetic graft replacement or bypass graft implantation is performed. However, there are limited data in endovascular era.

METHODS

We present a case of a 68-year-old male with a history of late EVAR graft occlusion treated with multiple surgical interventions (femorofemoral crossover, extra-anatomic bypass surgery, and thrombectomy) five years ago. Color Doppler ultrasound (CDUS) and computed tomography (CT) angiography revealed thrombosis of the entire bypass graft. Endovascular recanalization and remodeling of the abdominal stent graft CTO was performed with a combination of bare stents and stent grafts. Rupture of the stent graft occurred on the right limb. A second covered stent was placed.

RESULTS

At 12-month follow-up, the patient was symptom free. Color Doppler ultrasound surveillance showed patent aortic stent graft and downstream arteries.

CONCLUSIONS

Endovascular recanalization of aortic stent graft CTO is a viable option in patients with failed bypass graft.

Limb Occlusion Rate after EVAR With Individualized Graft Limb Selection and a Liberal Protocol of Primary Relining

BACKGROUND

This study analyses limb occlusion rates after endovascular aneurysm repair (EVAR) with a strategy including stent-graft limb selection and liberal primary stenting (relining) in anatomies at higher risk for occlusion with uncovered self-expandable or balloon-expandable stents.

METHODS

All patients undergoing elective EVAR with a bifurcated stent-graft between January 2010-August 2018 were included. A protocol involving personalized stent-graft selection and liberal primary relining based on preoperative imaging was followed during the whole period. Primary endpoints were technical success and primary limb patency during follow-up. Secondary endpoints included mortality and limb reintervention rates. Risk factors associated to limb patency and reintervention rates were analyzed.

RESULTS

Six hundred and fifteen patients (548 males; mean age 72.9 ± 9 years) were included. Overall technical success was 98.5% (606/615). One (0.16%) patient died during the first 30 days. Of the 1230 limbs, 96 (8%) were deemed at risk for occlusion in view of the anatomy, and primarily relined in 62 patients. Estimated primary limb patency at 6 months, 1 year and 3 years was 99.5 ± 0.2%, 99.2 ± 0.3% and 98.5 ± 0.5%, respectively. Freedom from limb-related reintervention at 6 months, 1 year and 3 years was 98.1 ± 0.4%, 97.4 ± 0.5% and 95.6 ± 0.7%, respectively. Only one (1%) of the 96 relined limbs occluded during follow-up. No differences were found in terms of patency or freedom from reintervention between limbs at risk that were primary stented and limbs without adjunctive stents. Gore Excluder stent-grafts presented better patency (Breslow P = 0.005) and lower reintervention rates (Breslow P = 0.001) than other devices during follow-up. Peripheral artery disease was also a risk factor for reintervention (Breslow P = 0.015).

CONCLUSION

Liberal use of primary limb relining in patients with iliac anatomy at higher risk for occlusion appears to be a safe and effective strategy to preserve limb patency after EVAR. Gore Excluder graft limbs present better patency and lower reintervention rates than other stent-graft types.

Surveillance Imaging following Endovascular Aneurysm Repair: State of the Art

Endovascular aneurysmal repair (EVAR) has become a prominent modality for the treatment of abdominal aortic aneurysm. Surveillance imaging is important for the detection of device-related complications, which include endoleak, structural abnormalities, and infection. Currently used modalities include ultrasound, X-ray, computed tomography, magnetic resonance imaging, and angiography. Understanding the advantages and drawbacks of each modality, as well available guidelines, can guide selection of the appropriate technique for individual patients. We review complications following EVAR and advances in surveillance imaging modalities.

Risk Factors for Early and Late Iliac Limb Occlusions of Stent Grafts Extending to the External Iliac Artery after Endovascular Abdominal Aneurysm Repair

BACKGROUND

Iliac limb stent grafting to the external iliac artery (EIA) is a commonly performed procedure in various situation during endovascular abdominal aneurysm repair (EVAR). However, this procedure is associated with a risk of graft occlusion. We evaluated risk factors affecting occlusion among patients who underwent iliac limb stent-graft extension to the EIA.

MATERIALS AND METHODS

We compared occluded limbs with patent limbs during the follow-up period using variables, including anatomical values, demographics, and other factors. Thereafter, we divided the occluded limbs into early and late occlusion subgroups. The main and subgroup analyses used the same variables. Survival analysis was performed to evaluate time-dependent risk factors for late limb occlusion.

RESULTS

From 2007 to 2016, 766 iliac limbs from 383 patients who underwent EVAR were initially included in our analysis. Among them, 134 iliac limbs underwent limb extension to the EIA. The limb extension was a significant risk factor for occlusion (hazard ratio = 6.34, P < 0.001). Occlusion occurred in 10 patients who underwent iliac limb extension. The size of common iliac artery (CIA) was associated with occlusion. The most significant factor was iliac bifurcation diameter (patent vs. occluded limbs, 21.6 ± 7.6 vs. 27.5 ± 9.5 mm, P = 0.005). Subgroup analysis revealed that the CIAs of the early occlusion subgroup were generally more tortuous (1.16 ± 0.33 vs. 1.47 ± 0.25, P = 0.091) and longer (53 ± 24 vs. 74 ± 9, P = 0.01) than those of the patent limb group. In addition, the EIA diameters of the late occlusion subgroup were narrower than those of the patent limb group (10.9 ± 1.6 mm vs. 9.1 ± 0.8 mm, P = 0.011). Using the log-rank test, those patients with an EIA diameter narrower than 10.1 mm had a higher risk for late limb occlusion (log-rank χ² = 5.73, P = 0.017) and the patients who did not take at least a single antiplatelet agent had a significantly higher chance of limb occlusion (log-rank χ² = 11.029, P = 0.001). In addition, the patients who did not take a statin had a higher risk for late limb occlusion (log-rank χ² = 7.41, P = 0.007).

CONCLUSIONS

Among patients who underwent EVAR with iliac limb extension, the CIA length affected early limb occlusion and predisposed patients to vessel injury or stent-graft kinking, and there was the possibility that CIA tortuosity was associated with a higher risk. The late occlusion subgroup had narrower EIAs than the patent limb group. Appropriate antiplatelet and statin therapy is expected to play a key role in the prevention of late limb occlusion after EVAR.

Geometrical changes in Anaconda endograft limbs after endovascular aneurysm repair: A potential predictor for limb occlusion

The emergence of limb occlusion after endovascular aneurysm repair may be related to the conformational changes between the endograft structure and the patient's anatomy. This study analyzed detailed geometric changes of Anaconda endograft (Terumo Aortic, Inchinnan, Scotland, UK) limbs during the cardiac cycle-based computed tomography on serial imaging after graft implantation. Fifteen patients (mean age 72.8 ± 3.7 years; 14 men) underwent postoperative electrocardiogram-gated computed tomography scans according to a prospective study design between April 2014 and May 2017. Changes in curvature, length of the limbs, and distances between successive stent rings (inter-ring distance) of the endograft limbs during a 2-year follow-up period were quantified using meticulous image processing methods involving image registration, centerline extraction, and model-based stent-ring segmentation. From discharge to 24 months, mean curvature increased significantly by 9.6 m^-1 (standard deviation [SD], 11.1 m^-1; 95% confidence interval [CI], 3.4 to 15.8 m^-1; P = .002) for the right limbs and by 6.1 m^-1 (SD 9.4 m^-1; 95% CI, 0.8 to 11.5 m^-1; P = .21) for the left limbs. The length of the right limbs decreased significantly, by 9.5 mm (SD 7.6 mm; 95% CI, 3.5 to 15.6 mm; P = .002); the length of the left limbs decreased by 10.1 mm (SD 5.1 mm; 95% CI, 5.9 to 14.2 mm; P < .001). The minimal inter-ring distance decreased by 0.36 mm (SD 0.26 mm; 95% CI, 0.17 to 0.55 mm; P < .001) for the right limbs and 0.35 mm (SD 0.19 mm; 95% CI, 0.21 to 0.49 mm; P < .001) for the left limbs. Cardiac pulsatility-induced changes in curvature, limb length, and inter-ring distance were negligible (2%, 0.3% and 0.3%, respectively). Changes in the geometry of the Anaconda endograft limbs after endovascular aortic aneurysm repair were observed during a 2-year follow-up manifest as an increase in curvature, shortening of the stent-graft limbs, and a corresponding decrease in inter-ring distance. These stent-graft conformational changes could result in inward folding of the graft fabric, which may relate to the emergence of limb occlusion. Further investigation of these metrics in a larger cohort involving patients with and without occlusions may allow determination of their predictive value.

Outcomes of Endovascular Aneurysm Repair Using the Anaconda Stent-Graft

Purpose: To report outcomes of elective endovascular aneurysm repair (EVAR) using the Anaconda stent-graft in a tertiary vascular center. Materials and Methods: A retrospective study was conducted of 271 patients (mean age 71.5 years; 260 men) who underwent elective EVAR for abdominal aortic aneurysm using the Anaconda stent-graft from January 2006 to January 2017. Median aneurysm diameter was 58 mm (range 50-90). All patients were anatomically suitable for EVAR according to the 2003 version of the instructions for use. Follow-up included computed tomography angiography at 1, 6, and 12 months and yearly thereafter for the first 4 years and then every 2 years. Primary outcomes included technical success and 30-day aneurysm-related mortality and complications; secondary outcomes were overall and aneurysm-related mortality and aneurysm-related morbidity in follow-up. Results: The Anaconda stent-graft was implanted successfully in all patients. Primary and secondary technical success rates were 99.6% and 100%, respectively. Three patients (1.1%) died within 30 days of causes unrelated to the aneurysm, while 15 patients (5.5%) suffered perioperative complications. Median follow-up was 72 months (range 14-141). The overall type I endoleak rate was 4.7% (11 proximal, 2 distal). Late aneurysm-related complications were observed in 48 patients (17.3%); aneurysm-related mortality was 1.4% (n=4). Non-aneurysm-related mortality was 21.0% (n=57). Freedom from reintervention was 95.2% at 1 year, 98% at 2 years, and 90% at 6 years. There was no significant difference in the overall limb graft occlusion rate between the second- and third-generation devices. Conclusion: Results in our cohort study demonstrate that the Anaconda stent-graft has satisfactory early and late results with low aneurysm-related mortality.

Aortoenteric Fistula through a Thrombosed Graft

Patient: Male, 75-year-old

Final Diagnosis: Aortoenteric fistula through a thrombosed graft

Symptoms: Hematochezia • melena

Medication:—

Clinical Procedure: Excision of the aortic graft, pyloric exclusion and loop gastrojejunostomy

Specialty: Surgery

Effect of the Terminal Aortic Diameter on the Patency Rate of Iliac Limbs after Endovascular Aortic Repair

Objective: Endograft limb occlusion (ELO) is a complication of endovascular aneurysm repair (EVAR). In this study, we investigated the mechanism and anatomical features of ELO.

Materials and Methods: We retrospectively reviewed 227 consecutive patients with abdominal aortic aneurysm who underwent EVAR between 2007 and 2017. We then analyzed the preoperative risk factors and anatomical features of patients with ELO.

Results: A total of nine patients had ELO (4.0%). The diameter of the terminal aorta was significantly smaller in patients with ELO than in patients without ELO (18.0 mm vs. 22.3 mm, p=0.039). We measured the diameter of each limb near the terminal aorta. The smaller limb (SL) was occluded in all patients with occlusion. The difference between the larger limb (LL) and the SL (LL-SL) was significantly larger in patients with ELO than in patients without ELO (4.0 mm vs. 1.7 mm, p<0.001). The following were considered risk factors for ELO: younger age, narrow terminal aorta, severe calcification at the terminal aorta, and use of an Endurant device.

Conclusion: ELO occurs when the diameter of one side of the stent graft limb is small compared with the diameter of the other side owing to the narrow terminal aorta and calcification.

Contemporary imaging methods for the follow-up after endovascular abdominal aneurysm repair: a review

Abdominal aortic aneurysm (AAA) is defined as a localized enlargement of the aortic cross-section where the diameter is greater than 3 cm or more than 50% larger than the diameter in a normal segment. The most important complication of AAA is rupture, which, if untreated, results in mortality rates of up to 90%. Conventional open surgical repair is associated with significant 30-day mortality. Endovascular aneurysm repair (EVAR) is a significantly less invasive procedure; it is related to a lower early mortality rate and a lower number of perioperative complications. Although EVAR is a minimally invasive technique, lifelong follow-up imaging is necessary due to possible late complications including endoleak, recurrent aneurysm formation, graft infection, migration, kinking and thrombosis. The total rate of complications after EVAR is estimated at approximately 30%, and the rate of complications that require intervention is 2–3%. Early detection and progression analysis of such situations is crucial for proper intervention.

Long-Term Outcomes of Percutaneous Stenting of Aortic Endograft Limb Occlusion

INTRODUCTION

To investigate the safety and efficacy of percutaneous stenting for the management of chronic ischemia caused by endograft limb occlusion following endovascular aortic aneurysm repair (EVAR).

METHODS

This is a retrospective, single-center study investigating all patients who underwent percutaneous endovascular covered or bare metal stent placement for the management of intermittent claudication (IC) or critical limb ischemia following EVAR limb occlusion, between January 2010 and October 2017. Cases suffering from acute limb ischemia were treated surgically and were excluded from the analysis. Primary outcome measures were technical success and symptoms-free interval. Secondary outcome measures included clinically driven target-lesion reintervention (TLR)-free survival, primary patency, and complication rates.

RESULTS

Of 29 limb occlusions, 11 limbs (11 patients; 100% male; mean age: 71.6 ± 6.9 years) were treated percutaneously and were included in the study. The majority suffered from IC (10/11; 90.9%) with a single case of rest pain. Technical success was obtained in 10 patients (90%). No major complications occurred. Mean follow-up time was 37.6 ± 25.7 months. Stent grafts were mainly used, while and in 2 cases (18.18%), only nitinol bare stents were deployed. According to Kaplan-Meier analysis, both symptoms-free interval and primary patency were 83.33% in up to 5 years follow-up. TLR-free survival was 100% at 5 years, as 2 cases of claudication relapse were managed conservatively.

CONCLUSIONS

Percutaneous stenting for the management chronic ischemia due to EVAR limb occlusion is feasible and safe, with satisfactory long-term outcomes. Careful patient selection warrants clinical success.

Abdominal aortic aneurysms: pre- and post-procedural imaging

Abdominal aortic aneurysm (AAA) is a relatively common, potentially life-threatening disorder. Rupture of AAA is potentially catastrophic with high mortality. Intervention for AAA is indicated when the aneurysm reaches 5.0-5.5 cm or more, when symptomatic, or when increasing in size > 10 mm/year. AAA can be accurately assessed by cross-sectional imaging including computed tomography angiography and magnetic resonance angiography. Current options for intervention in AAA patients include open surgery and endovascular aneurysm repair (EVAR), with EVAR becoming more prevalent over time. Cross-sectional imaging plays a crucial role in AAA surveillance, pre-procedural assessment, and post-EVAR management. This paper will discuss the current role of imaging in the assessment of AAA patients prior to intervention, in evaluation of procedural complications, and in long-term follow-up of EVAR patients.

Early and Mid-Term Results of Endovascular Aortic Repair Using a Crossed-Limb Technique for Patients with Severely Splayed Iliac Angulation

Objective: We evaluated early and mid-term results of endovascular aortic repair (EVAR) using crossed-limb and non-crossed-limb techniques.

Material and Methods: From December 2011 to October 2013, 37 patients (31 men; mean age 75.4 years) were treated with EVAR (crossed-limb, 21 and non-crossed-limb, 16). We compared technical success, maximum short-axis diameter of abdominal aortic aneurysm, iliac angulation, time for catheterization of the short contralateral limb gate of the main body (SCT), and complications between the groups.

Results: The mean follow-up period was 810±230 days. The technical success rate was 100%. There was no significant difference between the groups in terms of mean short-axis diameter. Iliac angulation was significantly wider in the crossed-limb group (53.3±14.6 vs. 39.4±13.0, p=0.0049). There was no significant difference between the groups in terms of SCT. Limb occlusion occurred in two cases (one crossed-limb and one non-crossed-limb). There were no aneurysm-related deaths.

Conclusion: There were no differences between the crossed-limb and non-crossed-limb techniques in terms of early and mid-term results of EVAR. A crossed-limb technique can be performed safely without prolonged SCT even in severely splayed iliac angulation cases.

Atypical Endoleak Associated With Inadvertent Cannulation of the Ipsilateral Gate in an Ovation Trimodular Stent-Graft

We report on a 54-year-old man who presented with an atypical, proximal, intraoperative endoleak after endovascular aortic repair with an Ovation endograft for a 65-mm-diameter abdominal aortic aneurysm. The endografting was complicated by inadvertent bilateral iliac limb insertion into the right gate without cannulation of the left gate. The endoleak was treated by brachial approach: Through the open left gate, the outflow inferior mesenteric artery was coil embolized and the inflow left gate was closed with an Amplatzer plug. Follow-up computed tomography over 3 years showed absence of any endoleak and a stable diameter of the excluded abdominal aortic aneurysm.

The emergency medicine approach to abdominal vascular graft complications

INTRODUCTION

Abdominal aortic aneurysm (AAA) is a deadly condition, particularly with rupture. Emergency physicians provide vital frontline care to the diagnosis and treatment of this disease. Endovascular aortic repair (EVAR) has become the gold standard for treatment of AAA, but the management of EVAR complications is not well discussed in the emergency medicine literature.

OBJECTIVE OF THIS REVIEW

The purpose of this article is to provide an emergency medicine-focused review of the complications of EVAR.

DISCUSSION

Although many complications may arise after AAA repair, the most common include aortoenteric fistula, endoleak, limb ischemia, and graft infection. All potential complications should receive vascular surgery consultation and hemodynamic resuscitation. Aortoenteric fistula often presents nonspecifically with gastrointestinal (GI) bleeding, abdominal pain, and vomiting. Computed tomography with intravenous contrast is required for diagnosis. An endoleak is defined by vascular flow outside of the graft. The optimal diagnostic modality includes triple phase computed tomographic scan (noncontrast, arterial, delayed phase). Limb ischemia may occur before 2 months, or in a later period, with symptoms ranging from claudication to complete neurovascular compromise. Graft infection is most commonly due to Staphylococcus aureus, and imaging can suggest the diagnosis. Definitive diagnosis requires tissue or fluid sampling. Through an understanding of these complications, emergency physicians may improve patient outcomes.

CONCLUSIONS

With the growing use of EVAR, emergency physician exposure to complications of this procedure is increasing. Knowledge of the complication presentations, diagnoses, and management can play an integral role patient care.

Endovascular repair of abdominal aortic aneurysms: vascular anatomy, device selection, procedure, and procedure-specific complications

Abdominal aortic aneurysm (AAA) is abnormal dilatation of the aorta, carrying a substantial risk of rupture and thereby marked risk of death. Open repair of AAA involves lengthy surgery time, anesthesia, and substantial recovery time. Endovascular aneurysm repair (EVAR) provides a safer option for patients with advanced age and pulmonary, cardiac, and renal dysfunction. Successful endovascular repair of AAA depends on correct selection of patients (on the basis of their vascular anatomy), choice of the correct endoprosthesis, and familiarity with the technique and procedure-specific complications. The type of aneurysm is defined by its location with respect to the renal arteries, whether it is a true or false aneurysm, and whether the common iliac arteries are involved. Vascular anatomy can be divided more technically into aortic neck, aortic aneurysm, pelvic perfusion, and iliac morphology, with grades of difficulty with respect to EVAR, aortic neck morphology being the most common factor to affect EVAR appropriateness. When choosing among the devices available on the market, one must consider the patient's vascular anatomy and choose between devices that provide suprarenal fixation versus those that provide infrarenal fixation. A successful technique can be divided into preprocedural imaging, ancillary procedures before AAA stent-graft placement, the procedure itself, postprocedural medical therapy, and postprocedural imaging surveillance. Imaging surveillance is important in assessing complications such as limb thrombosis, endoleaks, graft migration, enlargement of the aneurysm sac, and rupture. Last, one must consider the issue of radiation safety with regard to EVAR.

Percutaneous approach to the treatment of a totally occluded abdominal aortic stent graft

Aorto femoral bypass is usually the recommended therapy for diffuse disease involving the aorta and iliac arteries. In this case report, a case involving a chronic endovascular abdominal aortic stent graft occlusion in which percutaneous angioplasty was performed via a transbrachial and transfemoral approach is presented. This case emphasized that occlusion of an endovascular abdominal aortic stent graft can also be treated, primarily, with an endovascular technique.

Total Occlusion of Abdominal Aortic Endograft Successfully Treated with Axillobifemoral Bypass

We report a case of total occlusion of a Zenith bifurcated stent graft 16 months after implantation. A 72-year-old man was admitted to our hospital complaining of bilateral lower extremity numbness, followed by severe rest pain 4 h after sudden onset of symptoms. Computed tomography showed total occlusion of the endograft at the mid-portion of the main body. He underwent left axillobifemoral bypass using a reinforced polytetrafluoroethylene T-shaped graft, leading to resolution of symptoms 7 h after onset. Axillobifemoral bypass successfully relieved acute lower extremity ischemia caused by total occlusion of the abdominal aortic endograft.

Surveillance Imaging Following Endovascular Aneurysm Repair

There is a significant risk of complication following endovascular abdominal repair (EVAR), including endoleak, graft translocation, thrombosis, and infection. Surveillance imaging is important for detecting EVAR complication. Surveillance modalities include conventional X-ray, computed tomography, magnetic resonance imaging, ultrasound, and conventional angiography, with inherent advantages and drawbacks to each modality. The authors present common complications following EVAR, and recent advances in the key modalities for surveillance.

Sealing zones have a greater influence than iliac anatomy on the occurrence of limb occlusion following endovascular aortic aneurysm repair

Limb occlusion is a well-known complication following endovascular aortic aneurysm repair (EVAR), and it very often leads to reoperation. The aim of this study is to identify predictive factors for limb occlusion following EVAR. Two hundred and twenty-four patients undergoing EVAR between 2004 and 2012 were included in this retrospective study. Demographics, anatomic, and follow-up data were compared between two groups (with or without thrombosis). Preoperative anatomy was analyzed with a dedicated workstation, using the Society of Vascular Surgery reporting standards. Eleven (4.9%) patients presented with a limb occlusion during follow-up (46 ± 12 months). Univariate analyses were first performed to investigate the influence of preoperative variables on limb occlusion. Then, variables with a p value <0.1 were included in the multivariate analysis and showed that in the occlusion group there was a greater rate of chronic renal failure (18.2% vs. 3.8%, p = 0.012), a more frequent occurrence of distal landing zones in the external iliac artery (15.4% vs. 2.1%, p = 0.006), and a smaller aortic neck diameter (21.0 ± 2.9 mm vs. 23.6 ± 3.3 mm, p = 0.014). Although iliac anatomy does not appear to have a significant influence on limb occlusion rate in the multivariate analysis, proximal and distal sealing zones appear to be involved in this complication.

Studying the Interaction of Stent-Grafts and Treated Abdominal Aortic Aneurysms

Since the advent of endovascular repair of aortic aneurysms (EVAR), clinical focus has been on preventing loss of sealing at the level of the infrarenal neck, which leads to type I endoleak and repressurization of the aneurysm sac. Enhanced mechanisms for central fixation and seal have consequently lowered the incidence of migration and endoleaks. However, endograft limb thrombosis and its causal mechanisms have not been addressed adequately in the literature. This article reviews the pathophysiological mechanisms associated with limb thrombosis in order to facilitate better clinical judgment to prevent iliac adverse effects.

Initial single-center experience with the Ovation stent-graft system in the treatment of abdominal aortic aneurysms: application to challenging iliac access anatomies

BACKGROUND

To present our preliminary results with the Ovation(™) abdominal stent-graft system in abdominal aortic aneurysms (AAA) with narrow (≤7 mm) or angulated iliac vessels.

METHODS

From April 2012 to January 2014, 42 patients (97% men; mean age, 71 years; range, 55-89 years) with AAAs of 55.5 mm (50-79 mm) were treated with the Ovation device. Primary end points included technical success and freedom from early secondary interventions, any type of endoleak, and aneurysm-related death. Limb occlusion was studied with respect to iliac access diameter and angulation. Iliac angulation between 90° and 120° or <90° was considered moderate or severe, respectively.

RESULTS

The postoperative follow-up was 7.8 ± 4.6 months (mean ± standard deviation). Infrarenal neck angulation was 26° ± 26°. AAA neck length and diameter were 27.3 ± 10.5 and 24.1 ± 3.2 mm, respectively. Forty-five percent of patients had at least 1 vessel of ≤7-mm diameter, and almost half of patients (24 of 44) had at least 1 iliac artery of moderate or severe angulation. Technical and treatment success were 100% and 95%, respectively. No stent-graft migration or type I, III, or IV endoleaks occurred. Type II endoleaks were identified in 5 patients, leading to sac enlargement in 2 and necessitating an embolization attempt that was unsuccessful in 1 case. No limb occlusion occurred, irrespective of the iliac diameter or angulation.

CONCLUSIONS

Our 1-year results of the Ovation stent-graft system demonstrate excellent safety and effectiveness. The easy navigation through highly angulated and stenosed iliac vessels ensures high technical success in cases of challenging iliac anatomy. Follow-up is ongoing.

Essentials of endovascular abdominal aortic aneurysm repair imaging: postprocedure surveillance and complications

OBJECTIVE

Lifelong postprocedural imaging surveillance is necessary after endovascular abdominal aortic aneurysm repair (EVAR) to assess for complications of endograft placement, as well as device failure and continued aneurysm growth. Refinement of the surveillance CT technique and development of ultrasound and MRI protocols are important to limit radiation exposure.

CONCLUSION

A comprehensive understanding of EVAR surveillance is necessary to identify life-threatening complications and to aid in secondary treatment planning.

Results of the endovascular abdominal aortic aneurysm repair using the Anaconda aortic endograft

OBJECTIVE

The objective of this study was to evaluate early and late results of the Anaconda aortic endograft (Vascutek, Terumo, Inchinnan, Scotland) in a single-center experience.

METHODS

From September 2005 to March 2012, patients underwent endovascular aortic repair for abdominal aortic aneurysm (AAA) with Anaconda endograft were prospectively enrolled in a dedicated database. Demographic and aortoiliac morphological data were considered. Preoperative planning was based on thoracoabdominal and pelvic computed tomography angiography. Follow-up included duplex ultrasound or computed tomography angiography at 1, 6, and 12 months and yearly thereafter. Primary end points were technical success, early and late primary and primary assisted clinical success (CS), overall and AAA-related survival and freedom from reinterventions. Secondary end points were endoleaks (ELs), steno-obstructive iliac leg complications, and AAA shrinkage.

RESULTS

An Anaconda endograft was implanted in 177 patients (male 94%; mean age, 73.3 ± 7.4 years; American Society of Anesthesiologists class III-IV, 85% and 9%, respectively). The mean AAA diameter, neck length, and diameter were 55 ± 9.7 mm, 26.7 ± 10 mm, and 23 ± 2.3 mm, respectively. There was an aortic neck angle >60° in 44 (25%) patients. Iliac angles >90° were observed in 152 (43%) iliac axes. Technical success was 98.9%. Early CS was 96%. Mean follow-up was 33 ± 23.3 months. Late assisted CS was 97.7%. Survival at 12, 24, and 36 months was 96.4%, 89%, and 86.2%, respectively. There was only one case of late AAA-related mortality. Freedom from reintervention was 94%, 92%, and 85% at 12, 24, and 36 months, respectively. Three (1.7%) conversions occurred during follow-up. There were 14.1% ELs at the completion angiography (EL Ia, 1.1%; EL II, 13%). Late ELs were 20.2% (EL Ia, 1.1%; EL Ib, 2.2%; EL II, 16.9%). Iliac leg complications occurred in 5.6% of the cases. An AAA shrinkage >5 mm was observed in 130 (73.4%) patients. In 7 (4%) cases there was an AAA enlargement >5 mm.

CONCLUSIONS

Data in our series demonstrate that the Anaconda endograft has good early and late results in the treatment of AAAs.

A modified technique for Gore Excluder limb deployment in difficult iliac anatomy during endovascular abdominal aortic aneurysm repair

Complex iliac anatomy including extreme tortuosity constitutes a relative contraindication for endovascular abdominal aortic aneurysm repair with additional risk of limb-graft occlusion. The Gore Excluder limb-graft is a flexible stent-graft, which adapts easily to iliac tortuosity. Nevertheless, the presence of the stiff guide wire does not always allow for an ideal apposition of the stent graft to the angulated common iliac artery vessel wall. We describe herein a modified technique for Gore Excluder limb-graft deployment with partial removal of the stiff wire in cases with difficult tortuous or narrow iliac arteries during endovascular abdominal aortic aneurysm repair.