Natural history of common iliac arteries after aorto-aortic graft insertion during elective open abdominal aortic aneurysm repair: A prospective study

Gender-Specific Long-Term Results After Elective Open Abdominal Aortic Aneurysm Repair Depending on the Site of Distal Anastomosis

OBJECTIVE

Analysis of gender-specific differences in short- and long-term outcome after elective open abdominal aortic aneurysm repair (OAR) regarding the distal anastomosis.

METHODS

In this retrospective cohort study, data from 4853 patients of a German health insurance company undergoing OAR for infrarenal abdominal aortic aneurysms (AAAs) between 2010 and 2016 were analysed. The patients were followed through 2018.

RESULTS

A total of 4050 (83.5%) men and 803 (16.6%) women underwent OAR. Women were older than men (72.9 ± 8.7 vs 69.8 ± 8.5 years; P < .001). A tube graft was used in 2644 (54.5%) patients, an aorto-biiliac bifurcated graft in 1657 (34.1%) and an aorto-bifemoral bifurcated graft in 552 (11.4%). Perioperative mortality was not significantly different between men (5.7%) and women (6.5%) in the total patient population (P = .411). This was true for aorto-aortic tube grafting (P = .361), aorto-biiliac reconstructions (P = 1.000) and aorto-bifemoral reconstructions (P = .345). Kaplan-Meier estimated long-term survival of men after 9 years was better than that of women (55.0% vs 43.8%; P = .006). However, separated by the site of the distal anastomosis, this was only true for aorto-aortic reconstructions (survival men vs women 56.0% vs 42.1%; P = .005), not for aorto-biiliac and aorto-bifemoral reconstructions. In the multivariate Cox regression analysis, age over 80 years, heart failure, aorto-bifemoral reconstruction, chronic kidney disease stage 3-5, chronic obstructive pulmonary disease, peripheral artery disease, arterial hypertension, but not gender (P = .531), had a negative impact on long-term survival.

CONCLUSION

If possible, an aorto-aortic tube graft should be preferred to aorto-biiliac and aorto-bifemoral reconstructions in OAR. Patients selected for aorto-bifemoral artery reconstruction exhibit higher perioperative morbidity and mortality as well as worse long-term survival compared to patients selected for an intra-abdominal reconstruction. In the multivariate regression analysis, gender was not an independent risk factor for either short- or long-term outcomes.

Aortobifemoral reconstruction in open abdominal aortic aneurysm repair is associated with increased morbidity and mortality

OBJECTIVE

Much attention has been given to the influence of anatomic and technical factors, such as maximum abdominal aortic aneurysm diameter and proximal clamp position, in open abdominal aortic aneurysm repair (OSR). However, no studies have rigorously examined the correlation between site of distal anastomosis and OSR outcomes despite conventional wisdom that more proximal sites of anastomosis are preferrable when technically feasible. This study aimed to test the association between sites of distal anastomosis and clinical outcomes for patients undergoing primary elective OSR.

METHODS

Our study included 5683 patients undergoing primary elective OSR at 233 centers from 2014 to 2020. Using a variety of statistical methods to account for potential confounders, including multivariable logistic regression and Cox proportional hazards modeling, as well as subgroup analysis, we examined the association between site of distal anastomosis and clinical outcomes in elective OSR. Primary outcomes were major in-hospital complication rate, 30-day mortality, and long-term survival.

RESULTS

Patients undergoing elective aortobifemoral reconstruction (n = 672) exhibited significantly increased rates of smoking, chronic obstructive pulmonary disease, and peripheral artery disease in comparison to patients undergoing elective OSR with distal anastomosis to the aorta (n = 2298), common iliac artery (n = 2163), or external iliac artery (n = 550). Patients undergoing aorto-aortic tube grafting were significantly less likely to exhibit iliac aneurysmal disease and significantly more likely to be undergoing elective OSR with a suprarenal or supraceliac proximal clamp position. Using multivariable logistic regression and Cox proportional hazards analysis to control for important confounders, such as age, smoking status, and medical history, we found that distal anastomosis to the common femoral artery was associated with increased odds of major in-hospital complications (adjusted odds ratio, 1.79; 95% confidence interval, 1.46-2.18; P < .001) and reduced long-term survival (adjusted hazard ratio, 1.44; 95% confidence interval, 1.09-1.89; P = .010). We observed no significant differences in 30-day mortality across sites of distal anastomosis in our study population.

CONCLUSIONS

It is generally accepted that more proximal sites of distal anastomosis should be selected in OSR when technically feasible. Our findings support this hypothesis by demonstrating that distal anastomosis to the common femoral artery is associated with increased perioperative morbidity and reduced long-term survival. Careful diligence regarding optimization of preoperative health status, perioperative care, and long-term follow-up should be applied to mitigate major complications in this patient population.

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.

Endovascular Treatment of Aorta-Iliac Aneurysms with a Flared Iliac Limb

Endovascular abdominal aneurysm repair (EVAR) relies on the quality of the proximal and distal landing zone. Reinterventions are higher in patients with suboptimal landing zone. The study aimed to evaluate reintervention rate after endovascular treatment of an aorta-iliac aneurysm using the flared iliac limbs. The retrospective study included 179 patients treated with EVAR at a single university hospital institution from January 2011 to January 2014 of which 75 patients (42%) were treated with flared iliac limb stent graft and 104 patients (58%) were treated with a nonflared iliac limb stent graft. There were 165 male patients (92%), mean age was 75.8 ± 6.6 years. Thirty-six patients underwent secondary treatment accounting for overall reintervention rate of 20%. Endoleak type 1b occurred in 13 patients (7%), followed by endoleak type 1a in six patients (3%). Endoleak type 2 occurred in seven patients (4%) requiring the treatment due to abdominal aortic aneurysm (AAA) enlargement, endoleak type 3 in three patients (2%), and leg stent graft thrombosis in seven patients (4%). In 143 patients (80%), there were no secondary interventions during the follow-up period. Reintervention due to endoleak type 1b was statistically significantly higher in a flared iliac limb group ( p  < 0.02) with the rate of 7.2% compared with 1.9% rate in nonflared iliac limb group. The mean follow-up was 44.3 ± 20.4. Overall mortality was 33%. Flared iliac limb with a distal diameter of ≥ 20 mm, show a higher rate of iliac limb reintervention in a follow-up period due to endoleak type 1b.

Preservation of hypogastric flow and control of iliac aneurysm size in the treatment of aortoiliac aneurysms using the Nellix EndoVascular Aneurysm Sealing endograft

OBJECTIVE

The purpose of this study was to determine the long-term effectiveness of endovascular aneurysm sealing (EVAS) in the treatment of complex aortoiliac aneurysms with preservation of hypogastric artery flow.

METHODS

We reviewed all patients with abdominal aortic aneurysms (AAAs) and common iliac aneurysms (CIAs) enrolled and treated in prospective studies of EVAS using the Nellix endograft (Endologix, Irvine, Calif) at two centers from 2008 to 2014. Patients with 1 year or more of computed tomography follow-up underwent quantitative morphometric assessment by two independent vascular radiologists blinded to clinical outcome results. Hypogastric patency and CIA diameter changes over time were assessed and compared in three treatment groups: totally excluded CIA, partially excluded CIA, and untreated CIA.

RESULTS

Among 125 patients with EVAS, 68 patients (mean age, 75 ± 8 years; 79% men) had both AAA (mean diameter, 55.8 ± 2.0 mm) and CIA (median diameter, 23.4; interquartile range, 21.3-27.0 mm), with bilateral CIAs in 33 patients. Treatment of 101 CIAs included complete CIA exclusion in 40 (39.6%), partial CIA exclusion in 33 (32.7%), and no CIA treatment in 28 (27.7%), with successful AAA exclusion in all patients. Internal iliac flow was preserved in all 122 hypogastric arteries that were patent before treatment (14 hypogastric arteries were occluded at baseline). During the 5-year follow-up period (median follow-up, 24.7 months; range, 11.5-61.7 months), three patients required secondary treatment with hypogastric occlusion and graft extension to the external iliac. Thus, internal iliac flow was maintained in 98% of at-risk hypogastric arteries. There were no aneurysm-related clinical events, except for the three secondary treatments. Totally excluded iliac aneurysms did not change in diameter over time (P = .85), whereas untreated CIAs enlarged at a rate of 0.16 mm/y (95% confidence interval, 0.09-0.23; P < .0001). Partially excluded CIAs enlarged at a higher rate of 0.59 mm/y (95% confidence interval, 0.47-0.71; P < .0001). Enlargement ≥3 mm occurred only in partially treated CIAs larger than 3 cm.

CONCLUSIONS

EVAS was effective in treating aortoiliac aneurysms with preservation of internal iliac patency in most cases. Complete CIA exclusion prevented aneurysm enlargement over time, whereas partial exclusion did not prevent continued CIA enlargement, particularly in larger aneurysms.

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.

U Stent-Graft Technique as a Treatment for Homolateral Metachronous Common Iliac and Internal Iliac Arteries Aneurysms after Open Surgery

We report a case of a metachronous common iliac artery and the internal iliac artery (IIA) aneurysm developed 8 years after an aortobi-femoral bypass for treatment of abdominal aortic aneurysm associated at chronic occlusion of the right iliac axis. To exclude the metachronous aneurysm on the left iliac axis and to maintain the pelvic circulation, an external to IIA endografts were positioned ("U stent-graft technique"). At 6-month follow-up, the computed tomography scan showed patency of the endografts, of the bypass and of the IIA, without endoleak, or other adverse events.

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.

A comparative study of the bell-bottom technique vs hypogastric exclusion for the treatment of aneurysmal extension to the iliac bifurcation

INTRODUCTION

A significant proportion of patients undergoing endovascular aneurysm repair (EVAR) have common iliac artery aneurysms (CIAA). Aneurysmal involvement at the iliac bifurcation potentially undermines long-term durability.

METHODS

Patients with CIAA who underwent EVAR were identified in two teaching hospitals. Bell-bottom technique (BBT; iliac limb ≥20 mm) or internal iliac artery embolization and limb extension to the external iliac artery (IIE + EE) were used. Outcome between these two approaches was compared.

RESULTS

We identified 185 patients. Indication for EVAR included asymptomatic abdominal aortic aneurysm (AAA) in 157, symptomatic or ruptured aneurysm in 19, and CIAA in nine. Mean AAA diameter was 59 mm. Among 260 large CIAAs that were treated, BBT was used to treat 166 CIAA limbs, and 94 limbs underwent IIE + EE. Total reintervention rates were 11% for BBT (n = 19) and 19.1% for IIE + EE (n = 18; P = .149). Rates of reintervention for type Ib or III endoleak were 4% for BBT (n = 7) and 4% for IIE + EE (n = 4; P > .99). The difference in limb patency rates was not significant. The 30-day mortality rate was 1%. Median follow-up was 22 months. Complications did not differ significantly between the two groups; however, the combined incidence of perioperative complications and reinterventions was higher in the IIE + EE group (49% vs 22%; P = .002).

CONCLUSIONS

The combined incidence of perioperative complications and reinterventions is significantly higher with IIE + EE than with BBT; therefore, when feasible, BBT is desirable.

Fate of iliac arteries following open abdominal aortic aneurysm repair

Iliac artery aneurysms are a frequent finding in patients with abdominal aortic aneurysms. The decision of whether to perform a tubular or bifurcated repair rests on a balance between the natural history of the iliac arteries during the lifetime of the patient versus the risk of symptomatic pelvic ischemia and the increased complexity of a bifurcated repair. The relatively recent increase in the use of cross-sectional imaging, especially in the setting of long-term endograft surveillance, has provided useful data on which to base these clinical decisions. A tube graft repair appears to be safe and durable in patients undergoing open aneurysm repair, when suitable distal aortic anatomy and normal iliac arteries are present. A bifurcated graft should be considered in younger patients with moderate sized iliac aneurysms (<30 mm in diameter), as well as in almost all patients with larger iliac aneurysms.