The Zenith Aortic Stent-Graft:A 5-Year Single-Center Experience

Coupling bifurcated stent-grafts to overcome anatomic limitations of endovascular repair of abdominal aortic aneurysms

PURPOSE

To evaluate the effectiveness of the coupling stent-graft technique and outcomes on contrast-enhanced computed tomography (CT).

MATERIALS AND METHODS

All patients who underwent endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs) between 2007 and 2010 at a single institution were retrospectively analyzed. Of the 161 cases, 19 patients who had coupling stent-grafting because of AAA proximal neck angulation greater than 60°, conical neck, or iliac tortuosity were included. Patient age ranged from 62 to 87 years (mean, 73.3 y). Mean follow-up was 18.7 months (range, 1-36 mo). The coupling stent-graft technique was defined by the use of suprarenal fixation device main bodies (Zenith or Talent) with one or more EXCLUDER limbs to adapt tortuous and angulated iliac arteries. Pretreatment contrast-enhanced CT was analyzed based on three-dimensional and multiplanar reformatted images. Follow-up contrast-enhanced CT was also analyzed.

RESULTS

Mean aneurysm diameter was 68.9 mm ± 14.0, neck length was 32.7 mm ± 15.1, and neck angulation was 68.9° ± 11.5. Conical neck shapes were present in four patients (21.1%) and ruptured AAAs were present in two (10.5%). Among 38 iliac arteries, the mean iliac artery tortuosity index was 1.52 ± 0.27 and iliac angle was 106.8° ± 18.1. Three patients (15.8%) underwent repeat intervention: placement of a balloon-expandable stent in the proximal neck for type I endoleak (n = 1), endovascular embolization for proximal type I endoleak (n = 1), and percutaneous approach following endovascular embolization for type II endoleak (n = 1). No type III endoleak, limb occlusion, limb kinking, or stent-graft migration developed.

CONCLUSIONS

The coupling stent-graft technique is technically feasible, with acceptable midterm outcomes in EVAR of AAA in patients with unfavorable neck and iliac anatomies.

Detecting Endoleaks in Aortic Endografts Using Contrast-Enhanced Sonography

OBJECTIVE

We performed this pilot study to investigate the utility of contrast-enhanced sonography for the detection of endoleaks in patients with abdominal aortic endografts.

CONCLUSION

Contrast-enhanced sonography evaluation of abdominal aortic endografts is a technically feasible alternative to our current practice standard.

Experience With Endovascular Abdominal Aortic Aneurysm Repair in Nonagenarians

PURPOSE

To report a single-institution experience with endovascular abdominal aortic aneurysm (AAA) repair (EVAR) in nonagenarians.

METHODS

A retrospective review was performed of all patients >90 years old undergoing EVAR over an 8-year period at a major academic medical center. The patient population was investigated for the presence of various comorbidities, initial aneurysm size, successful aneurysm exclusion, perioperative complications, disposition, endoleaks, secondary interventions, and overall survival.

RESULTS

EVAR was performed in 18 male nonagenarians (mean age 92.4 years, range 90- 95). Mean aneurysm diameter was 7.3 cm (range 5.5-9.8). The cohort had an average of 3.2 comorbid conditions. Sixteen patients were treated electively, while 2 patients underwent emergent repair for contained rupture and bleeding aortoenteric fistula, respectively. Immediate technical success was 100%. Perioperative local/vascular complications occurred in 4 (22%) patients. Perioperative systemic complications occurred in 3 (17%) patients. There were 2 (11%) perioperative (<30 days) deaths. Three (17%) patients required secondary interventions. Mean survival in patients who expired during the follow-up period beyond the first 30 days was 34 months (range 8-78). Mean survival in 8 patients who are still alive is 17.4 months (range 9-39).

CONCLUSION

Endovascular AAA repair in nonagenarians is associated with a high rate of technical success and relatively low morbidity rate. Survival times following successful hospital discharge are significant. Suitable patients over 90 years of age may benefit from an endovascular AAA repair.

Aorfix stent graft for abdominal aortic aneurysms reduces the risk of proximal type 1 endoleak in angulated necks: bench-test study

Neck angulation (NA) is an important risk factor for type 1 proximal endoleaks following stenting of abdominal aortic aneurysms. The Aorfix (Lombard Medical, Oxon, UK) is a new flexible stent graft designed to overcome this issue. The aim of this study was to compare the endoleak flow rate (EFR) in relation to NA between the Aorfix and other manufactured stent grafts. A flow model with silicone proximal and distal necks was used. EFRs corresponding to 10 neck angles between 0 and 70 degrees were measured. Eight stent grafts were tested: Aorfix, Ancure (Guidant, Indianapolis, IN), Powerlink (Endologix, Irvine, CA), AneuRx (Medtronic, Sunnyvale, CA), Excluder (W.L. Gore & Associates, Flagstaff, AZ), Zenith and Zenith-Flex (Cook Inc., Bloomington, IN), and Lifepath (Edwards Lifesciences, Irvine, CA). For all stent grafts except the Aorfix, the EFR was greater than at baseline for NA >or= 30 degrees (p < .01). The EFR at NA >or= 30 degrees was lower with the Aorfix compared with the other stent grafts (p < .01). NA had no influence on the EFR with the Aorfix. The Aorfix may decrease the incidence of proximal type 1 endoleak in patients with a severely angulated aortic neck.

Late problems at the proximal aortic neck: Migration and dilation

Migration is a late-term complication of endovascular aneurysm repair (EVAR) evidenced by downward slippage of the endograft. The etiology of migration may be inherent to problems with endograft fixation, although aortic neck dilation may also play a role. Devices with active fixation (ie, hooks and barbs) possess an additional mechanism of fixation and may better resist migration. Aortic neck dilation after EVAR is significant in a subset of patients and may be related to neck degeneration. Excessive oversizing of endografts may contribute to dilation and migration and is, therefore, not recommended. Migration should be treated when the overlap between the endograft and aortic neck is less than 10 mm or when associated with clinically significant events such as type I endoleak or aneurysm expansion. Failure to treat migration could lead to repressurization and subsequent rupture of the aneurysm.