Predisposing Factors for Migration of the Iliac Limb and Reintervention after Endovascular Abdominal Aortic Aneurysm Repair

Treatment strategies for endoleak after endovascular repair of the abdominal aortic aneurysm: A single center retrospective study

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) is the most frequently used treatment for aneurysm in abdominal aorta. The endoleak after EVAR causes the aneurysm sac to remain enlarged and risk for rupture.

AIMS

The purpose of the study was to assess the efficacy of strategies and techniques for endoleak treatment.

METHODS

This study was a single center retrospective study of 30 patients who had kinds of endoleak. The 30 patients were from a cohort of 597 patients who received EVAR from the Secondary Xiangya Hospital, Central South University between Jan 2014 to Dec 2021, what is follow-up well and diagnosed as endoleak. Data included basic clinical information, aspects of the endoleak treatment techniques, and follow-up findings.

RESULTS

The 30 patients with endoleak were diagnosed by computed tomography angiography or digital subtraction angiography. Age is 69 ± 7.9 yrs. 26 patients are male with only 4 female patients. Immediate endoleak after EVAR is 46.7%and delayed endoleak is 53.3%. The classification of endoleak is type Ⅰ:76.6%; type Ⅱ 26.7%; type Ⅲ:6.7%; type Ⅳ:6.7%; type Ⅴ:13.3%. Different treatment of endoleak includes: screening, endovascular re-intervention and open surgery. There are 3 patients (10.0%) underwent emergency EVAR due to their rupture condition of aneurysm. All the endoleak patients' CTA image characteristics has been reviewed. The follow-up rate is 93.3%. There are 6 patients (21.4%) died during follow-up. No aneurysm sac rupture death has been recorded.

CONCLUSIONS

Endoleak after EVAR is the most frequent complication that directly affects survival and re-intervention rates. Our findings suggested that different treatment strategies based on the individual patient's situation is important for their endoleak treating result.

The Impact of Iliac Artery Anatomy on Distal Landing Zone After EVAR During the 12-Month Follow-Up

BACKGROUND

Proximal sealing zone has been the main interest in endovascular abdominal aortic aneurysm repair (EVAR), although the distal landing zone remodeling may also affect EVAR durability. The aim of this study was to assess iliac anatomy and its potential impact on distal landing zone adverse events after EVAR during the 12-month follow-up.

METHODS

A prospective data collection of patients treated with standard bifurcated EVAR devices for abdominal aortic aneurysm was undertaken between 2017 and 2019. Patients that received extension to the external iliac artery were excluded. Follow-up included computed tomography angiography (CTA) at the 1st and 12th month postoperatively. The common iliac artery (CIA) diameter was assessed in three levels: origin (just below the aortic bifurcation), distally (just above the iliac bifurcation) and the middle of the distance between these two landmarks. Iliac angle, tortuosity indexes, relining and oversizing were also analyzed. Distal landing zone-related adverse events were any limb related re-intervention, endoleak type Ib, graft migration, limb stenosis, or occlusion.

RESULTS

In total, 268 iliac limbs (134 patients) were included. In all three levels, the mean iliac artery diameters increased at 12-month follow-up. At the origin of the CIA, the diameter increased from 18.7 ± 10.5 mm to 19.9 ± 9.4 mm (P = 0.04), at the middle portion of the CIA, the diameter changed significantly from 15.5 ± 5.1 mm to 17.4 ± 5.4 mm (P < 0.001) and at the distal CIA, from 14.6 ± 3.3 mm to 15.1 ± 3.9 mm (P = 0.03). The iliac angle remained stable (P = 0.14) while the CIA index decreased significantly from 1.17 ± 0.13 to 1.11 ± 0.09 (P < 0.001). The mean value of oversizing was 21.5 ± 14.5% and affected distal iliac diameter increase (P < 0.001). The composite outcome of distal landing zone adverse events was not associated to diameter changes at any level. In 57 cases, a distal iliac diameter ≥18 mm was recorded. The estimated oversizing was lower (16.3 ± 11.8%) compared to <18 mm arteries (22.5 ± 14.9%, P = 0.01). At 12-month follow-up, iliac diameters remained stable in the ≥18 mm group. Endoleak type Ib was more common in iliac arteries ≥18 mm [3 (5.3%) vs. 1 (0.5%) (P = 0.04)] at 12-months.

CONCLUSIONS

Post-EVAR iliac artery dilation does not seem to have an impact on distal landing zone adverse events during the 12-month follow-up. Aggressive oversizing may be related to iliac dilation. EVAR patients with iliac arteries ≥18 mm are at higher risk for ET Ib.

CT angiography for the assessment of EVAR complications: a pictorial review

Endovascular aneurysm repair (EVAR) is a minimally invasive treatment proposed as an alternative to open repair in patients with abdominal aortic aneurysms. EVAR consists in a stent-graft placement within the aorta in order to exclude the aneurysm from arterial circulation and reduce the risk of rupture. Knowledge of the various types of devices is mandatory because some stents/grafts are more frequently associated with complications. CT angiography is the gold standard diagnostic technique for preprocedural planning and postprocedural surveillance. EVAR needs long-term follow-up due to the high rate of complications. Complications can be divided in endograft device-related and systemic complications. The purpose of this article is to review the CT imaging findings of EVAR complications and the key features for the diagnosis.

Treatment of Complete Displacement of the Bilateral Legs into an Aortic Aneurysm Using an Iliac Branch Device

PURPOSE

Migration is a major cause of reintervention after endovascular aneurysm repair (EVAR). In patients with common iliac artery (CIA) dilation due to proximal migration of the iliac limb, internal iliac blood flow can be preserved by implanting an iliac branch device (IBD).

CASE REPORT

In this report, we discuss the case of a patient in whom the bilateral limbs were completely displaced into the aortic aneurysm due to proximal migration of the iliac limb after EVAR. By taking advantage of the characteristics of this migration, we formed a pull-through wire through the native terminal aorta without passing through the flow divider of the stent graft, and the IBD was deployed safely.

CONCLUSION

The present case indicates that the preservation of at least 1 internal iliac artery is possible in patients with CIA dilation due to proximal migration of the iliac limb. However, the unique features of each case must be considered to determine the appropriate approach.

Unibody bifurcated aortic endograft: device description, review of the literature and future perspectives

The unibody (Powerlink/AFX/AFX2) Endovascular AAA device (Endologix Inc., CA, USA) presents a unique design with its long main body and two innate limbs. The device is designed to be deployed and sits on the native aortoiliac bifurcation and represents the only one-piece bifurcated endograft designed to use anatomical fixation for endograft stabilization. According to published literature, the unibody device seems to represent a valid choice in the treatment of abdominal aortic aneurysms. This particular device would seem to satisfactorily perform even in the treatment of more compressed aneurysms (also in off-label association with parallel grafts) and in occlusive pathologies. Ongoing studies will provide new real-life data in a large and unselected patient population to better understand the device’s advantages and limitations.

Results of the Galician registry in the treatment of complex aortoiliac aneurysms with GORE® EXCLUDER® Iliac Branch Endoprosthesis (GALIBER)

OBJECTIVE

The objective of this study is to report the medium-term results of GORE^® EXCLUDER^® Iliac Branch Endoprosthesis (IBE, W. L. Gore & Associates, Flagstaff, Ariz) for the treatment of aortoiliac aneurysms by using the GALIBER registry.

METHODS

Patients with aortoiliac or isolated common iliac/hypogastric aneurysms treated with Iliac Branch Endoprosthesis device between January 2014 and May 2019 were prospectively collected from 5 centers. Demographic, clinical, and radiologic data were extracted from electronic databases. Technical success was defined as successful implantation of the Iliac Branch Endoprosthesis device with exclusion of aortoiliac aneurysm, as well as patency of Iliac Branch Endoprosthesis in the follow-up. Iliac Branch Endoprosthesis patency was evaluated by Doppler ultrasound and/or computed tomography based on the protocol of each participant center. Follow-up was 731 days +/- 499.

RESULTS

Between January 2014 and May 2019, 105 iliac arteries were treated with GORE^® IBE device, in 81 patients (79 men, two women; mean age 71, range 52-91). Only seven patients (8.6%) were symptomatic. 60 patients (74%) had aortic and iliac enlargement. Thirty-three patients presented bilateral iliac aneurysms (40.7%): In twenty-four (29.6%) patients, an Iliac Branch Endoprosthesis device was implanted in both sides, and in nine patients (11.1%), one Iliac Branch Endoprosthesis was used with the embolization of the contralateral hypogastric artery. Technical success was achieved in the 99% (104/105 iliac branch device implanted). There were no procedural deaths or type I or III intraoperative endoleaks observed. During the follow-up (range 55-1789 days), 28 (34.5%) type II endoleaks were observed and one (1.2%) type Ia was observed. The patency of the hypogastric arteries treated with the iliac branch device was 98.1% during the follow-up (range 55-1789 days). In 30% of the patients with contralateral hypogastric embolization, some kind of complications was observed in the embolizated side: one developed ischemic colitis and two buttock claudication.

CONCLUSIONS

Preservation of internal iliac artery with the Iliac Branch Endoprosthesis device can be performed safely with excellent technical success and good medium-term patency rates. These results support hypogastric preservation whenever possible to prevent ischemic complications.

Effect of limb oversizing on the risk of type Ib endoleak in patients after endovascular aortic repair

OBJECTIVE

We assessed the association between the degree of limb oversizing and the risk of type Ib endoleak (TIBEL) in different types of iliac landing zones after endovascular aortic aneurysm repair.

METHODS

We performed a retrospective cohort study of patients who had undergone endovascular aortic aneurysm repair with bifurcated and limb endografts in an academic center. The main exposure was the degree of limb oversizing. The primary outcome was the occurrence of TIBELs. The secondary outcomes included limb occlusion, reintervention, and overall survival. Subgroup analyses stratified by ectatic and normal iliac landing zones were performed. Multivariate Cox regression analysis and sensitivity analyses using marginal structure model were conducted to adjust for potential confounders.

RESULTS

A total of 750 patients with 1500 iliac limb endografts were included in our study (817 limbs with oversizing of ≤10% and 683 with oversizing >10%). The median 1-year freedom from TIBEL was 98.9% (interquartile range [IQR], 98.0%-99.8%) for limbs with oversizing of ≤10% and 99.6% (IQR, 99.0%-100%) for limbs with oversizing >10%. The median 3-year freedom from TIBEL was 95.6% (IQR, 93.1%-98.1%) and 98.2% (IQR, 96.5%-99.9%) for oversizing ≤10% and >10%, respectively. We found that limb oversizing >10% was associated with a significantly decreased risk of TIBEL (adjusted hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.19-0.76) in the overall population. After stratification by ectatic iliac landing zone, we found that limb oversizing >10% was associated with a significantly decreased risk of TIBEL in the ectatic iliac landing zones (adjusted HR, 0.38; 95% CI, 0.16-0.88). However, no significant difference was found in the limb endografts landing in normal iliac arteries (adjusted HR, 0.44; 95% CI, 0.13-1.45). In the subgroup of normal iliac arteries, we observed a significantly increased risk of limb occlusion in the limbs with distal oversizing >15% compared with the limbs with distal oversizing of ≤15% (adjusted HR, 4.66; 95% CI, 1.68-12.91).

CONCLUSIONS

Adequate limb oversizing >10% was associated with a significantly decreased risk of TIBEL in limbs with ectatic iliac landing zones. However, no additional benefit was observed for oversizing >10% in limb grafts landing in normal iliac arteries. Furthermore, excessive limb oversizing (>15%) in normal iliac landing zones can be associated with an increased risk of limb occlusion.

Impact of Compliance with Anatomical Guidelines of "Bell-Bottom" Iliac Stent Grafts for Ectatic or Aneurysmal Iliac Arteries

OBJECTIVE

To evaluate the impact of compliance with anatomical guidelines on outcomes of endovascular aortic aneurysm repair using "bell-bottom" stent grafts (BBSGs).

METHODS

This is a retrospective review from January 1999 to May 2012 of patients who underwent endovascular infrarenal abdominal aneurysm repair and whose iliac limbs were greater than 18 mm in diameter. Computed tomography angiography was utilized for compliance with anatomical guidelines as stated in manufacturer's instructions for use (IFU). The primary outcome observed was iliac limb events. The secondary outcome observed was the need for re-intervention due to BBSG failure.

RESULTS

Of the 376 BBSGs, 55 (15%) in 27 patients met IFU. Aneurysm exclusion was achieved in all patients. The mean follow-up was 44 ± 30 months. Twenty-eight patients (11%) had 29 iliac limb events (12 type 1b endoleaks, 4 aneurysm sac growth, 4 stenosis/kink, 4 retrograde migrations, 2 component separations, 2 ruptures and 1 limb occlusion); all among patients treated outside of IFU (p < 0.04). The rate of aneurysm sac enlargement was similar between both groups, at 56%, respectively, between those treated within and those treated outside of IFU. On multivariate regression analysis, larger common iliac artery (CIA) (HR 1.088, 95% CI 1.016-1.166, p = 0.016), greater CIA tortuosity (HR 2.352, 95% CI 1.004-5.509, p = 0.048) and limbs with more than two characteristics that did not meet IFU criteria (HR 3.84, 95% CI 1.15-12.83, p = 0.03) were associated with higher rates of BBSG events and re-interventions.

CONCLUSIONS

BBSGs effectively seal ectatic CIAs. But rates of iliac limb events and re-interventions are higher among patients who do not meet IFU criteria. The larger CIA diameter, the greater CIA tortuosity and more than two criteria not met by IFU were associated with BBSG failure and re-intervention.