Anatomical Suitability of the GORE EXCLUDER Iliac Branch Endoprosthesis in Japanese Patients with Common Iliac Aneurysms Treated by Standard EXCLUDER Endografts

Multicenter CT Image-Based Anatomic Assessment of Patients with Aortoiliac Aneurysm Undergoing Endovascular Repair with Iliac Branch Devices

BACKGROUND

The Global Iliac Branch Study (NCT05607277) is an international, multicenter, retrospective cohort study of anatomic predictors of adverse iliac events (AIEs) in aortoiliac aneurysms treated with iliac branch devices (IBDs).

METHODS

Patients with pre-IBD and post-IBD computed tomography imaging were included. We measured arterial diameters, stenosis, calcification, bifurcation angles, and tortuosity indices using a standardized, validated protocol. A composite of ipsilateral AIE was defined, a priori, as occlusion, type I or III endoleak, device constriction, or clinical event requiring reintervention. Paired t-test compared tortuosity indices and splay angles pretreatment and post-treatment for all IBDs and by device material (stainless steel and nitinol). Two-sample t-test compared anatomical changes from pretreatment to post-treatment by device material. Logistic regression assessed associations between AIE and anatomic measurements. Analysis was performed by IBD.

RESULTS

We analyzed 297 patients (286 males, 11 females) with 331 IBDs (227 stainless steel, 104 nitinol). Median clinical follow-up was 3.8 years. Iliac anatomy was significantly straightened with all IBD treatment, though stainless steel IBDs had a greater reduction in total iliac artery tortuosity index and aortic splay angle compared to nitinol IBDs (absolute reduction -0.20 [-0.22 to -0.18] vs. -0.09 [-0.12 to -0.06], P < 0.0001 and -19.6° [-22.4° to -16.9°] vs. -11.2° [-15.3° to -7.0°], P = 0.001, respectively). There were 54 AIEs in 44 IBDs in 42 patients (AIE in 13.3% of IBD systems), requiring 35 reinterventions (median time to event 41 days; median time to reintervention 153 days). There were 18 endoleaks, 29 occlusions, and 5 device constrictions. There were no strong associations between anatomic measurements and AIE overall, though internal iliac diameter was inversely associated with AIE in nitinol devices (nAIE, nitinol = 8).

CONCLUSIONS

Purpose-built IBDs effectively treat aortoiliac disease, including that with tortuous anatomy, with a high patency rate (91.5%) and low reintervention rate (9.1%) at 4 years. Anatomic predictors of AIE are limited.

Outcomes of the Gore Excluder Iliac Branch Endoprosthesis for Japanese Patients With Aortoiliac Aneurysms: A Study Based on J-Preserve Registry

PURPOSE

To evaluate the clinical utility of the Gore Excluder iliac branch endoprosthesis (IBE) for Japanese patients with aortoiliac aneurysms.

MATERIALS AND METHODS

This was a multicenter retrospective cohort study (J-Preserve Registry). Patients undergoing endovascular aortic repair using the Gore Excluder IBE for aortoiliac aneurysms between August 2017 and June 2020 were enrolled. Data pertaining to the baseline and anatomical characteristics, technical details, and clinical outcomes were collected from each institution. The primary endpoints were technical success, IBE-related complications, and reinterventions. Secondary endpoints were mortality, aneurysm size change, and reintervention during follow-up. Technical success was defined as accurate deployment of the IBE without type Ib, Ic, or III endoleaks on the IBE sides on completion angiography. A change in aneurysm size of 5 mm or more was taken to be a significant change.

RESULTS

We included 141 patients with 151 IBE implantations. Sixty-five IBE implantations (43.0%) had at least one instruction for use violation. Twenty-two patients (15.6%) required internal iliac artery (IIA) embolization for external iliac artery extension on the contralateral side. Of 151 IBE implantations, 19 exhibited IIA branch landing zones due to IIA aneurysms. Mean maximum and proximal common iliac artery (CIA) diameters were 32.9±9.9 mm and 20.5±6.9 mm, respectively. The mean CIA length was 59.1±17.1 mm. The IIA landing diameter and length were 9.0±2.3 mm and 33.8±14.6 mm. The overall technical success rate was 96.7%. There were no significant differences in IBE-related complications (2.3% vs 5.3%, p=0.86) or IBE-related reinterventions (1.5% vs 5.3%, p=0.33) between the IIA trunk and IIA branch landing groups. The mean follow-up period was 635±341 days. The all-cause mortality rate was 5.0%. There were no aneurysm-related deaths or ruptures during the follow-up. Most patients (95.7%) had sac stability or shrinkage.

CONCLUSION

The Gore Excluder IBE was safe and effective for Japanese patients in the midterm. Extending the IIA device into the distal branches of the IIA was acceptable, which may permit extending indications for endovascular aortic aneurysm repair of aortoiliac aneurysms to more complex lesions.

CLINICAL IMPACT

This study suggests clinical benefits of the Gore Excluder IBE for Japanese patients, despite 43% of the IBE implantations having at least one IFU violation.

Alternative Endograft Aortoiliac Reconstruction for Iliac Branch Endoprostheses

BACKGROUND

Endovascular treatment of complex common iliac artery (CIA) and internal iliac artery (IIA) aneurysms using iliac branch endoprostheses (IBE) has proven safe and effective. Instructions for use (IFU) require deployment of current IBE technology with the corresponding manufacturer's modular bifurcated aortic endograft. Concomitant aortoiliac occlusive disease, inadequate renal artery-iliac bifurcation length, and unfavorable aortic anatomy preclude on-label IBE deployment. This study aimed to evaluate the technical feasibility and safety of Alternative Endograft Aortoiliac Reconstruction (AEGAR) for branched endovascular treatment of complex iliac artery aneurysms.

METHODS

In 7 consecutive patients with CIA or IIA aneurysms, computed tomography angiography (CTA) and center-line reconstruction revealed aortoiliac anatomy incompatible with the current IBE IFU due to inadequate proximal CIA landing zone (n = 7), inadequate renal artery to iliac bifurcation length (n = 2), compromised aortic anatomy (n = 3), or short infrarenal neck <15 mm (n = 1), either alone or in combination. To overcome these restrictions and facilitate IBE deployment, aortoiliac reconstruction was performed using the Endologix AFX, Endologix Ovation limbs or the Medtronic Endurant II platforms (AEGAR technique). All internal iliac artery reconstructions and external iliac artery extensions were performed using the Gore VBX or Viabahn stent grafts. Technical success was defined as successful delivery of all endograft components without migration or endoleak.

RESULTS

The mean patient age was 69 years (range 52-82 years; 6 male). Four patients had bilateral CIA aneurysms and 3 patients had unilateral CIA aneurysms (mean diameter 4.3cm; range 2.2-7 cm). There were 13 IIA VBX stent grafts used for a total of 9 IIAs treated with IBE (bilateral IBE = 2 patients). The mean fluoroscopy time was 38.8 min (range 21.3-64.3 min) and the mean contrast volume was 168.5 mL (range 122-226 mL). Technical success was achieved in all patients and there were no perioperative complications. Mean hospital-stay was 2.2 days (range 1-3 days). Follow-up ranged from 82-957 days (mean = 487 days). At last follow-up, all patients were alive without cardiovascular morbidity; and CTA revealed stable or decreased aneurysm size, patent endografts, and no evidence of endoleak or migration.

CONCLUSIONS

The AEGAR technique can be used to safely and effectively overcome certain aortoiliac anatomic constraints that preclude use of current IBE technology. We encourage broader use of these alternative endografts in pertinent anatomic configurations.

Early results of expanding the anatomical indications for using a Gore Iliac branch endoprosthesis to treat aortoiliac and iliac aneurysms

PURPOSE

To assess the safety and anatomical suitability of using a Gore Iliac Branch Endoprosthesis (IBE) in aortoiliac and iliac aneurysm repair.

METHODS

Between 2017 and 2020, 20 patients underwent endovascular aneurysm repair (EVAR) with a Gore IBE device (bilateral IBE, n = 1) after expanding the instructions for use (IFU) criteria. We evaluated the early clinical outcomes and suitability of the IFU criteria, retrospectively.

RESULTS

Six patients (30%) met all the IFU criteria. Anatomical suitability according to the IFU criteria for the collective total of 21 IBE limbs was confirmed for 10 (47.6%) proximal common iliac arteries, 21 (100%) external iliac arteries, 18 (85.7%) internal iliac arteries, and in the length from the lowest renal artery to the iliac bifurcation in 15 (71.8%) patients. Assisted primary technical success was achieved in all patients with various bail-out techniques. One patient (5%) required a bare-stent insertion 7 days after EVAR for severe stenosis in the ipsilateral limb caused by a small terminal aorta. There was no case of occlusion of an iliac branch component device.

CONCLUSIONS

Gore IBEs were implanted safely and effectively with various bail-out techniques to repair aortoiliac and iliac aneurysms in our Japanese patients with a low rate of inclusion IFU criteria.

The association between perioperative embolization of hypogastric arteries and type II endoleaks after endovascular aortic aneurysm repair

OBJECTIVE

Type II endoleaks (T2ELs) are the most common type of endoleak after endovascular aneurysm repair (EVAR). The iliolumbar artery arising from the hypogastric artery is often a major source of T2ELs, and transarterial embolization of the iliolumbar artery through the hypogastric artery is sometimes performed to interrupt sac expansion during follow-up. Considering the equivocal results of an association between hypogastric embolization and T2ELs in previous studies, this topic has re-emerged after the advent of iliac branch devices. This study reviewed our series to clarify whether hypogastric embolization is associated with T2ELs at 12 months after EVAR.

METHODS

Patients who underwent elective EVAR between June 2007 and May 2017 at our institution were retrospectively reviewed. Patients with postoperative computed tomography angiography (CTA) at 12 months were included. Patients in whom CTA revealed type I or type III endoleaks during follow-up, who required reinterventions before 12 months, and who had solitary iliac aneurysms were excluded. The primary outcome was the incidence of T2ELs at 12 months after EVAR. The associations of patients' characteristics, anatomic factors, hypogastric embolization, and type of endograft with the primary outcome were analyzed.

RESULTS

In total, 375 patients were enrolled. During the median follow-up of 59.5 months (interquartile range, 19-126 months), 40 patients died, and 50 reinterventions were performed. In 108 patients (28.8%), either hypogastric artery was embolized to extend distal landings to the external iliac artery. Bilateral and unilateral embolization was performed in nine and 99 patients, respectively. In total, 153 patients (40.8%) had T2ELs found by CTA at 12 months. In the univariate analysis, the status of hypogastric artery occlusion or embolization was not significantly different between patients with and without T2ELs. However, there were not enough patients to detect a 10% difference in T2ELs with >80% statistical power. In the multivariate analysis, significant associations with T2EL were observed for female sex (P = .049), patent inferior mesenteric artery (P = .006), and presence of five or more patent lumbar arteries (P < .001) but not for hypogastric embolization. In addition, compared with the Zenith (Cook Medical, Bloomington, Ind) endograft, the Excluder (W. L. Gore & Associates, Flagstaff, Ariz) endograft was significantly related to T2EL (P = .001).

CONCLUSIONS

No significant association between hypogastric embolization and T2EL was demonstrated in this retrospective study, which lacked adequate statistical power.

Preemptive angioplasty for contralateral leg stenosis following EXCLUDER Iliac Branch Endoprosthesis implantation

The GORE EXCLUDER Iliac Branch Endoprosthesis (IBE) device is designed to seal off a common iliac artery (CIA) aneurysm, preserving the internal iliac artery during endovascular aortic repair. We report the case of an 84-year-old man with isolated saccular right CIA aneurysm (35 mm) and a relatively small terminal aorta (24 mm). The IBE device was successfully placed, and intraoperative angiography revealed no leakage or delay. However, postoperative computed tomography revealed marked compression of the contralateral leg by a bridging component. Although his ankle-brachial index was preserved, its acute occlusion was judged highly possible; we decided to perform preemptive angioplasty. The angiography revealed the stenosis only in the left anterior oblique view, and angioplasty was uneventfully performed. The leg was successfully patent at 1-year follow-up. When compression by IBE and bridging component in the terminal aorta is expected, caution should be preserved at intraoperative angiography following the device deployment.

Importance of Distal Sealing during Endovascular Aneurysm Repair Using Aneurysmal Common Iliac Artery as Landing Zone

BACKGROUND

Although the use of aneurysmal common iliac artery (CIA) as the landing zone during endovascular aortic aneurysm repair EVAR remains an essential procedure, this procedure may increase the risk of late complications such as ongoing CIA dilatation and type Ib endoleak (CIA-related complications). We hypothesized that incomplete sealing of the aneurysmal CIA segment during EVAR could increase the incidence of CIA-related complications. In this study, we evaluated the midterm results of EVAR with aneurysmal CIA used as the landing zone and assessed the importance of distal sealing in this procedure.

METHODS

We retrospectively reviewed all cases of endovascular aneurysm repair using CIA as landing zone between 2007 and 2015 that had at least 3 years' follow-up. We defined aneurysmal CIA as maximum diameter ≥18 mm. The main outcome was the incidence of CIA-related complications. We compared midterm results between normal CIA and aneurysmal CIA. Next, we analyzed risk factors for CIA-related complications in aneurysmal CIA.

RESULTS

Four complications occurred in normal CIA (mean follow-up, 66.5 ± 22.1 months); 21 occurred in aneurysmal CIA (mean follow-up, 62.2 ± 20.5 months). The 5-year portion of freedom from CIA-related complications was 97.3% in normal CIA and 69.4% in aneurysmal CIA (P < 0.001). Multivariable analysis in aneurysmal CIA showed that unsealed CIA segment length was only risk factor for CIA-related complications. Given the receiver operating characteristic curve results, we defined the unsealed CIA segment ≥10 mm as incomplete sealing. The hazard ratio for incomplete sealing associated with CIA-related complications was 3.92 (95% confidence interval 1.62-9.46, P = 0.02).

CONCLUSIONS

Use of aneurysmal CIA as landing zone increases the risk of CIA-related complications. However, maximum sealing of the aneurysmal CIA segment could prevent these complications.