Endovascular Aortic Aneurysm Repair with the Zenith Endograft in Patients with Ectatic Iliac Arteries

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.

Fate of Enlarged Iliac Arteries After Endovascular or Open Abdominal Aortic Aneurysm Repair

Purpose: To examine the fate of untreated ectatic and aneurysmal common iliac arteries (CIAs) after open treatment and endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA). Methods: Databases of scientific literature were searched between January 1980 and February 2016 to identify publications on the follow-up of ectatic and aneurysmal CIAs after open or endovascular AAA repair. The primary outcome measure was the increase of iliac artery diameter during follow-up. The secondary outcome was the subsequent reintervention rate during follow-up. Results: Only 3 open AAA and 3 EVAR studies containing 1239 patients met the inclusion criteria for analysis. In the open AAA group, ectatic iliac arteries (defined as 12–18 mm) had a diameter progression of 1.7 to 1.8 mm during a follow-up period of 51.6 to 85.2 months. The aneurysmal iliac arteries (>18 mm) in the open repair group showed a faster growth (2.3–3.0 mm) in a follow-up period of 50.4 to 85.2 months. The pooled assessment of arteries ≥18 mm had a mean growth of 2.56 mm at 60 months of follow-up. In the entire open AAA cohort, the reintervention rate for CIA transformation was <1%. In the EVAR studies, arbitrary cutoff sizes of 16 to 20 mm for ectatic arteries and >20 mm for aneurysmal arteries were used. During a follow-up of 39.2 to 60 months, the diameter progression was 1.5 mm for the 16-mm iliac arteries and 2.7 mm for the 20-mm iliac arteries. The need for endovascular reinterventions was similar in patients with previously normal or enlarged CIAs. Conclusion: After open AAA repair, the overall size of CIA aneurysms grows slowly, but enlarged CIAs >20 mm in EVAR patients show faster growth during follow-up. However, the need for secondary interventions was similar in patients with normal or enlarged CIAs post EVAR.

Natural History of the Iliac Arteries after Endovascular Abdominal Aortic Aneurysm Repair and Suitability of Ectatic Iliac Arteries as a Distal Sealing Zone

Purpose:

To investigate the natural history of dilated common iliac arteries (CIA) exposed to pulsatile blood flow after endovascular abdominal aortic aneurysm repair (EVAR) and the suitability of ectatic iliac arteries as sealing zones using flared iliac limbs.

Methods:

Follow-up computed tomograms of 102 CIAs in 60 EVAR patients were investigated. Diameter changes in CIAs ≤16 mm (group 1) were compared with changes in vessels where a dilated segment >16 mm in diameter continued to be exposed to pulsatile blood flow (group 2). Within group 2, cases in which the stent terminated proximal to the dilated artery segment (2a) were compared with those that had been treated with a flared limb (2b).

Results:

The mean CIA diameter increased by 1.0±1.0 mm in group 1 (p<0.001 versus immediately after EVAR) and by 1.5±1.7 mm in group 2 (p<0.001 versus immediately after EVAR) within an average follow-up of 43.6±18.0 months. Diameter increase was more pronounced in dilated CIAs (p=0.048), and it was not significantly different between groups 2a and 2b (p=0.188). No late distal type I endoleak or stent-graft migration associated with CIA ectasia was observed.

Conclusion:

Dilatation of the CIA is significant after EVAR, and it is more pronounced in ectatic iliac arteries. Although ectatic iliac arteries appear to be suitable sealing zones in the short term, continued follow-up is mandatory.

Fate of Aneurysmal Common Iliac Artery Landing Zones Used for Endovascular Aneurysm Repair

PURPOSE

To determine outcomes of aneurysmal common iliac arteries (aCIA) used for landing zones (LZs) during endovascular aneurysm repair (EVAR).

METHODS

This single-center study retrospectively compared 57 EVAR patients (mean age 72±8 years; 56 men) with 70 aCIAs (diameter ≥20 mm) to 25 control EVAR subjects (mean age 73±7 years; 20 men) with 50 normal (≤15-mm) CIA LZs treated consecutively during the same time interval. The CIA LZ measurements were analyzed using random effects linear mixed models to determine diameter change over time. Life tables were used to estimate freedom from endoleak, reintervention, and all-cause mortality.

RESULTS

The mean maximum preoperative CIA diameter in the aCIA LZ group was 24.8±4.5 mm (range 20.0-47.3, median 23.9) vs 13.6±1.5 mm (range 9.2-15.0, median 13.9; p<0.001) in the controls. Nineteen aCIA LZs were treated outside the instructions for use of the device. Median follow-up in the aCIAs LZ cohort was 39.2 months [interquartile range (IQR) 15, 61] vs 49.3 months (IQR 36, 61) in the controls (p=0.06). The rate of aCIA LZ change (0.09 mm/mo, 95% CI 0.07 to 0.1) was significantly greater than controls (0.03 mm/mo, 95% CI -0.009 to 0.07; p<0.0001). No type Ib endoleaks developed in either group; however, aCIA LZ patients had 6 (11%) iliac limb-related reinterventions. There were significantly more endograft-related reinterventions in the aCIA LZ patients (n=10, 14%) compared with controls (n=2, 4%; p=0.06). There was no difference in mortality or freedom from any post-hospital discharge endoleak.

CONCLUSION

Aneurysmal CIA LZs used during EVAR experience greater dilatation compared with normal LZs, but no significant difference in outcome was noted in midterm follow-up. However, an increased incidence of graft limb complications or endograft-related reintervention may be encountered. Use of aCIA LZs appears to be safe; however, greater patient numbers and longer follow-up are needed to understand the clinical implications of morphologic changes in these vessels when used during EVAR.

Use of aortic extension cuffs for preserving hypogastric blood flow in endovascular aneurysm repair with aneurysmal involvement of common iliac arteries

BACKGROUND

Intentional hypogastric artery covering during endovascular repair of abdominal aortic aneurysms (EVAR) can carry a non-negligible rate of complications; to preserve pelvic blood flow, several approaches are in use, such as sandwich techniques, branched iliac devices, or the use of aortic extender cuffs in a bell-bottom configuration. We assess the performance of the latter for treatment of common iliac artery aneurysms during EVAR.

METHODS

Prospective gathering of data in 21 dilated common iliac arteries (18-25 mm) with coexisting abdominal aorta aneurysm, which were treated from 2005 to 2010 and received a GORE(®) Excluder endograft and one (n = 14) or several aortic extenders in a bell-bottom configuration. Control group consisted of 136 EVARs performed with the same device in the same time frame. Median follow-up was of 47 months, with contrast-enhanced computed tomography assessment 1 month after the procedure and yearly thereafter.

RESULTS

Age and comorbidities were homogeneously distributed among groups, although the aortic aneurysm diameter was lower in the bell-bottom group (50 mm vs. 58.2 mm, P < 0.001). There was no 30-day mortality registered in this group, and only one patient died during follow-up (5.3%), without relation with the aneurysmal disease. No significant differences were found in reintervention (15.8% vs. 14.7%, P = 0.707) or endoleak rates (36.8% vs. 38.9%, Fisher P = 1). There were no type I and four type II endoleaks, two of which precised treatment for sac growth. Endoleak-free survival (P = 0.994) and reintervention-free survival (P = 0.563) did not show differences either.

CONCLUSION

Bell-bottom technique is a feasible and safe alternative for preserving hypogastric blood flow, and does not imply a higher risk of reintervention or endoleak at 3-year follow-up.

Logistic Considerations for a Successful Institutional Approach to the Endovascular Repair of Ruptured Abdominal Aortic Aneurysms

The value of emergency endovascular aneurysm repair (EVAR) in the setting of ruptured abdominal aortic aneurysm remains controversial owing to differing results. However, interpretation of published results remains difficult as there is a lack of generally accepted protocols or standard operating procedures. Furthermore, such protocols and standard operating procedures often are reported incompletely or not at all, thereby making interpretation of results difficult. We herein report our integrated logistic system for the endovascular treatment of ruptured abdominal aortic aneurysms. Important components of this system are prehospital logistics, in-hospital treatment logistics, and aftercare. Further studies should include details about all of these components, and a description of these logistic components must be included in all future studies of emergency EVAR for ruptured abdominal aortic aneurysms.

Large iliac arteries: a high-risk group for endovascular aortic aneurysm repair

PURPOSE

To examine if the presence of large iliac arteries is a potential risk factor for the development of a type Ib endoleak (iliac sealing zone) or need for iliac artery-related secondary intervention in patients undergoing endovascular abdominal aortic aneurysm repair.

METHODS

The medical notes and all preoperative and postoperative plain abdominal radiographs and computer tomographic scans were reviewed for a consecutive series of 100 patients (89 men; mean age 75 years, range 56-91) with large iliac arteries (mean 19.7 mm, range 16-22) who had Zenith endovascular stent-grafts inserted for management of aortoiliac aneurysmal disease from January 1999 until September 2002. Endpoints were all-cause mortality, aneurysm-related death, endoleak, secondary intervention, secondary interventions, and stent-graft migration.

RESULTS

Mean follow-up was 30.1+/-8.3 months; at the last follow-up, 30% of patients were dead, 3% were aneurysm-related. Seven (7%) patients developed a type Ib endoleak, with the remainder being type II (29%), type Ia (2%), type III (1%), and type V (endotension, 1%). Eight (27.5%) type II endoleaks persisted, with the remainder closing spontaneously with sac shrinkage. The iliac artery-related secondary intervention rate was 10%, and the overall secondary intervention rate was 16%.

CONCLUSION

Iliac arteries between 16 and 22 mm in diameter may be treated with a cuff to the iliac limb with an expectation of 90% efficacy. Surveillance is required, with a high index of suspicion for type 1b endoleaks. Early secondary iliac intervention with extension to the external iliac artery is recommended if there is an increase in sac size after 6 months.

Outcome of common iliac arteries after straight aortic tube-graft placement during elective repair of infrarenal abdominal aortic aneurysms

PURPOSE

To determine the relative rates of common iliac artery (CIA) expansion after elective straight aortic tube-graft replacement of infrarenal abdominal aortic aneurysms (AAA).

METHODS

Five participating centers in this 2004 study entered patients they had managed by an aortoaortic tube graft for elective AAA repair. The procedures took place between January 1995 and December 2003. Postoperative computed tomography (CT) scans were obtained for all patients in 2004 to assess changes in CIA diameter. Measurements on preoperative and postoperative CT scans were all made at the same level using the same technique.

RESULTS

Entered in the study were 147 patients (138 men, 9 women) with a mean age of 68 years. Mean follow-up from aortic surgery to verification of CIA diameter on the postoperative CT scan was 4.8 years. Mean preoperative CIA diameter was 13.6 mm vs 15.2 mm postoperatively. No patient developed occlusive iliac artery disease during follow-up. Three patients (2%) required repeat surgery during follow-up for a CIA aneurysm. The 147 patients were divided into three groups based on preoperative CIA diameter shown in CT scan: group A (n = 59, 40.1%), both CIA were of normal diameter; group B (n = 53, 36.1%), ectasia (diameter between 12 and 18 mm) of at least one CIA; group C (n = 35, 23.8%), an aneurysm (diameter >18 mm) of at least one CIA. CIA diameter increased by a mean of 1 mm (9.4%) over 5.5 years in group A vs 1.7 mm (12.1%) over 4.3 years in group B and 2.3 mm (12.7%) over 4.2 years in group C. The three patients who required repeat surgery for a CIA aneurysm during follow-up were all in group C. Four variables were associated with aneurysmal change in CIA: initial CIA diameter, celiac aorta diameter on the preoperative CT scan, a coexisting aneurysm site, and the follow-up duration.

CONCLUSIONS

Tube-graft placement during AAA surgery is justified even for moderate CIA dilatation (<18 mm). CIA aneurysms with a preoperative diameter > or =25 mm enlarge more rapidly and warrant insertion of a bifurcated graft during the same surgical session as AAA repair. The evolutive potential of CIA between 18 mm and 25 mm in diameter justifies a bifurcated graft when the celiac aorta diameter is >25 mm or the patient's life expectancy is > or =8 years.

Endovascular repair of abdominal aortic aneurysms: CTA evaluation of contraindications

Endovascular aortic aneurysm repair (EVAR) is considered an acceptable alternative to open surgery in selected patients. Its feasibility depends mainly on anatomic factors that represent the important predictors of success and the most important exclusion criteria. Poor anatomic patient selection is generally associated with a higher risk for procedural complications and compromised long-term outcomes. Therefore pretreatment imaging is crucial for evaluating patient suitability for EVAR. Multidetector computed tomographic angiography represents the current standard of reference in the evaluation of the abdominal aorta and iliac axis anatomy because it provides all the details needed for selection of patients who are suitable for endograft and the choice of the appropriate device. This report identifies and reviews computed tomographic angiographic anatomic contraindications for EVAR.