Results of Endovascular Abdominal Aortic Aneurysm Repair with the Zenith stent-graft

Zenith AAA endovascular graft suprarenal bare metal stent separation with graft migration and type IA endoleak

BACKGROUND

The Zenith endovascular graft (Cook Medical, Bloomington, IN, USA) is a well-recognised device used in endovascular repair of abdominal aortic aneurysms (EVAR). After a small number of reported cases of suprarenal stent separation from the main body of the graft, modifications were made to the strength and durability of the suture line attachment of the proximal bare metal component prior to release in 2003. This report describes a further case of suprarenal stent separation and type IA endoleak in a patient who underwent an EVAR using the Zenith device in 2012.

METHODS

We present a case report of a 77-year-old male with incidental finding of type IA endoleak on a background of elective endovascular repair for 50.4-mm infrarenal abdominal aortic aneurysm (AAA), with a Cook Zenith endograft. Computed tomography (CT) demonstrated separation of the suprarenal bare metal stent from the main body of the endograft, with resultant graft migration and increase in native aneurysm sac size.

RESULTS

The patient underwent semi-urgent surgery with successful placement of a bridging thoracic stent graft between the lowest renal artery and main body of the pre-existing graft.

CONCLUSIONS

This case report describes a rare complication of Zenith devices, additionally emphasising the importance of regular surveillance imaging following EVAR.

What factors counteract mid-term survival following endovascular repair of abdominal aortic aneurysms?

Introduction

Endovascular aortic aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) is increasingly used, and has become the standard treatment option for AAA.

Aim

To evaluate the outcomes and predictors of survival of endovascular treatment of AAA in the short- and medium-term.

Material and methods

A total of 222 patients having endovascular AAA repair between January 2013 and December 2019 by the same surgical team were included in the study. Patient demographics, perioperative and follow-up data including mortality, complications, and need for secondary intervention were collected. The primary endpoint was all-cause mortality. Kaplan-Meier analysis was conducted for survival and Cox regression models were assessed for predictors of survival.

Results

The median age was 70 years, with male predominance (202 patients, 91%). Thirty-day mortality was 1.8%. Median follow-up to the primary endpoint was 20 months (range: 1–80 months). Survival rates at 1, 3, and 5 years were 93.5%, 81.4%, and 62.2%, respectively. Freedom from secondary intervention rates were 95.5% at 1 year, 88.7% at 3 years, and 82.1% at 5 years. Cox proportional hazard models showed that preoperative creatinine levels ≥ 1.8 mg/dl (hazard ratio (HR) = 2.68, 95% CI: 1.21–6.42, p = 0.027), haemoglobin levels < 10 gr/dl (HR = 3.38, 95% CI: 1.16–9.90, p = 0.026), ejection fraction < 30% (HR = 5.67, 95% CI: 1.29–24.86, p = 0.021), and AAA diameter ≥ 6.0 cm (HR = 2.20, 95% CI: 1.01–4.81, p = 0.049) were independently associated with mid-term survival.

Conclusions

EVAR is a safe procedure with low postoperative morbidity and mortality. This study confirms that the mid-term survival and results are favourable. However, the analysed factors in this study that predict reduced survival (high preoperative creatinine, low haemoglobin, low ejection fraction and larger aneurysms) should be judged when planning endovascular repair of AAA.

Endovascular Aneurysm Repair by Combining Different Endografts: the Zenith Body and Endurant Limbs

Purpose

There are several commercially approved stent grafts in Korea for the treatment of abdominal aortic aneurysms (AAAs). Each device has its advantages and disadvantages based on the patient’s anatomy and the clinical situation. The Zenith device allows accurate and precise endograft placement, whereas the Endurant device has improved flexibility and trackability. We reviewed 5 cases in which a combination of the Zenith main body and the Endurant iliac limb was used.

Materials and Methods

From January 2010 to February 2015, 90 patients with AAA underwent endovascular aneurysm repair (EVAR) using the Zenith body at Daegu Catholic University Hospital. Among them, 5 patients who underwent EVAR with the Zenith body and Endurant iliac limb were included in this study.

Results

The mean age of the patients was 74.20±3.35 years. All patients were men. The main reason for use of the Endurant iliac limb was aortoiliac angulation. Type III endoleak, stent migration, and stent kinking were not noted. Comparing 85 patients who received a Zenith endograft with 5 patients who received the hybrid endograft, there were no statistical differences in clinical characteristics, intraoperative details and post procedural complications. The mean admission duration was 19.00±13.60 days, and the mean follow-up duration was 1,018.11±925.34 days. In the hybrid endograft group, there was no mortality during the follow-up duration.

Conclusion

Although the material, radial force, diameter, and length of the overlap zone differ between the two devices, EVAR with the hybrid endograft is safe and effective.

Comparison of Endovascular Stent Grafts for Abdominal Aortic Aneurysm Repair in Medicare Beneficiaries

BACKGROUND

Increased renal complications have been suggested with suprarenal stent grafts, but long-term analyses have been limited. Therefore, the purpose of this study was to evaluate the effect of endograft choice on perioperative and long-term outcomes.

METHODS

We compared Medicare beneficiaries undergoing endovascular abdominal aortic aneurysms repair from 2005 to 2008 with endografts with infrarenal fixation and a single docking limb (AneuRx, Excluder) to those with suprarenal fixation and 2 docking limbs (Zenith), or a unibody configuration (Powerlink). Propensity score weighting accounted for differences in patient characteristics among the different graft formations, and perioperative mortality, complications, and length of stay and 4-year rates of survival, rupture, and reintervention were compared.

RESULTS

Forty-six thousand one hundred seventy-one Medicare beneficiaries were identified including 11,002 (24%) with suprarenal fixation, 32,909 (71%) with infrarenal fixation, and 2,260 (5%) with a unibody graft. After propensity score weighting, there were no significant differences in patients' baseline clinical and demographic characteristics. The suprarenal fixation patients had higher rates of perioperative mortality (1.7% vs. 1.3%, P < 0.01), renal failure (6.0% vs. 4.7%, P < 0.001), and mesenteric ischemia (0.7% vs. 0.4%, P < 0.01) and longer length of stay (3.4 days vs. 3.0 days, P < 0.001) compared with patients with infrarenal fixation. Unibody grafts had higher rates of renal failure (5.9% vs. 4.7%, P < 0.001), mesenteric ischemia (1.0% vs. 0.4%, P < 0.001), and conversion to open repair (0.7% vs. 0.1%, P < 0.001) compared to those with infrarenal fixation and single docking limbs. At 4 years, mortality remained slightly higher with suprarenal compared to infrarenal fixation (30% vs. 29%, P = 0.047), although these patients had fewer conversions to open repair (0.6% vs. 0.9%, P = 0.03) and aneurysm-related reinterventions (10% vs. 12%, P < 0.01). At 4 years, unibody grafts had more aneurysm-related interventions compared to infrarenal fixation grafts (15% vs. 12%, P < 0.01) but fewer conversions to open repair (0.4% vs. 0.9%, P = 0.02). Late rupture did not differ among the groups.

CONCLUSIONS

Compared to infrarenal fixation devices, patients who underwent EVAR with suprarenal fixation had higher perioperative mortality and renal complications but fewer reinterventions including conversion, while the unibody graft had more perioperative complications and aneurysm-related reinterventions, but fewer conversions to open repair. Although these differences could be explained by selection bias, these data suggest that further comparative effectiveness analyses should be performed to understand the outcomes following EVAR with suprarenal fixation and unibody grafts.

A Rare Complication After Endovascular Aneurysm Repair: Disconnection of the Suprarenal Stent of a Zenith Endograft

PURPOSE

To report a disconnection between the bare suprarenal stent and the main body of a Zenith endograft.

CASE REPORT

A 79-year-old man with a history of successful endovascular repair of an aortic aneurysm presented a sudden episode of hypotension and hematuria. He had undergone implantation of a Zenith bifurcated device 8 years earlier in 2006. Plain abdominal radiography and computed tomography showed disconnection of the uncovered proximal stent, which led to endograft migration and type Ia endoleak. The patient also presented with distal endoleaks at the attachment sites in both common iliac arteries. The aneurysm sac diameter had increased from 52 to 96 mm. A proximal aortic cuff and bilateral iliac extensions were deployed via a common femoral artery access. Completion angiography did not show endoleak.

CONCLUSION

After publication of a few such cases with the older Zenith device, the union between the suprarenal stent and main body was reinforced in 2002 to prevent this complication. Since modification of the device, this sequela had not been described. The reappearance of this complication underscores the need for continued surveillance, considering that these late events may require a reintervention to maintain the clinical success of the procedure.

Systematic Review and Meta-analysis of Long-term survival After Elective Infrarenal Abdominal Aortic Aneurysm Repair 1969-2011: 5 Year Survival Remains Poor Despite Advances in Medical Care and Treatment Strategies

Background

Improved critical care, pre-operative optimization, and the advent of endovascular surgery (EVAR) have improved 30 day mortality for elective abdominal aortic aneurysm (AAA) repair. It remains unknown whether this has translated into improvements in long-term survival, particularly because these factors have also encouraged the treatment of older patients with greater comorbidity. The aim of this study was to quantify how 5 year survival after elective AAA repair has changed over time.

Methods

A systematic review was performed identifying studies reporting 5 year survival after elective infrarenal AAA repair. An electronic search of the Embase and Medline databases was conducted to January 2014. Thirty-six studies, 60 study arms, and 107,814 patients were identified. Meta-analyses were conducted to determine 5 year survival and to report whether 5 year survival changed over time.

Results

Five-year survival was 69% (95% CI 67 to 71%, I² = 87%). Meta-regression on study midpoint showed no improvement in 5 year survival over the period 1969–2011 (log OR −0.001, 95% CI −0.014–0.012). Larger average aneurysm diameter was associated with poorer 5 year survival (adjusted log OR −0.058, 95% CI −0.095 to −0.021, I² = 85%). Older average patient age at surgery was associated with poorer 5 year survival (adjusted log OR −0.118, 95% CI −0.142 to −0.094, I² = 70%). After adjusting for average patient age, an improvement in 5 year survival over the period that these data spanned was obtained (adjusted log OR 0.027, 95% CI 0.012 to 0.042).

Conclusion

Five-year survival remains poor after elective AAA repair despite advances in short-term outcomes and is associated with AAA diameter and patient age at the time of surgery. Age-adjusted survival appears to have improved; however, this cohort as a whole continues to have poor long-term survival. Research in this field should attempt to improve the life expectancy of patients with repaired AAA and to optimise patient selection.

A modified technique for Gore Excluder limb deployment in difficult iliac anatomy during endovascular abdominal aortic aneurysm repair

Complex iliac anatomy including extreme tortuosity constitutes a relative contraindication for endovascular abdominal aortic aneurysm repair with additional risk of limb-graft occlusion. The Gore Excluder limb-graft is a flexible stent-graft, which adapts easily to iliac tortuosity. Nevertheless, the presence of the stiff guide wire does not always allow for an ideal apposition of the stent graft to the angulated common iliac artery vessel wall. We describe herein a modified technique for Gore Excluder limb-graft deployment with partial removal of the stiff wire in cases with difficult tortuous or narrow iliac arteries during endovascular abdominal aortic aneurysm repair.

Midterm results of the Zenith endograft in relation to neck length

BACKGROUND

Successful endovascular repair of abdominal aortic aneurysms (AAAs) requires specific infrarenal neck anatomy to allow for a durable seal and fixation. This is a single-center study reviewing outcomes in relation to neck length after placement of a Zenith endograft.

METHODS

Retrospective single-center review of all AAAs electively repaired with a Zenith endograft during a recent 5-year period. Patients were divided into those with infrarenal necks 4-15 mm in length and those >15 mm using center line measurements. Clinical outcomes and follow-up computed tomography scans were reviewed.

RESULTS

Between 2003 and 2008, 318 patients underwent elective repair of an infrarenal AAA with the Zenith endograft. Of 318 patients, 68 (21.4%) had necks measuring 4-15 mm in length and 250 (79.5%) had necks measuring >15 mm. Overall early mortality was 0.9% (p = 0.11) and the rate of type II endoleaks was 19% (p = 0.11); neither differed between the groups. Four patients in each group had immediate proximal type I endoleaks, which resolved spontaneously in two patients in each group. The remaining two in each group required further intervention (two endovascular and two conversion to open repair). Type I endoleaks and reinterventions did not differ statistically between groups (p = 0.06). On further analysis, those patients requiring reintervention or conversion for type I endoleaks had other unattractive neck features (large diameter, angulation). There have been no instances of new type I endoleaks during 5-yearfollow-up period.

CONCLUSION

These midterm results indicate that patients with shorter infrarenal necks can be treated as effectively as those with longer necks with the Zenith endograft unless these necks are tortuous or wide.

Hybrid Endograft Solution for Complex Iliac Anatomy: Zenith Body and Excluder Limbs

The purpose of this study was to evaluate single-center results with selective use of Gore Excluder limbs (W.L. Gore & Associates, Flagstaff, AZ) in a Cook Zenith body (Cook Inc, Bloomington, IN) for elective endovascular abdominal aortic aneurysm (AAA) repair. A prospectively held database for patients with AAA, who were treated endovascularly between March 1999 and July 2008, was queried for patients treated with a Cook Zenith body and one or two Gore Excluder limbs. Indication, technical success, late limb occlusion, and disconnection were evaluated. From 276 patients who were treated with a Zenith body, 29 underwent repair with hybrid graft components with, in total, 41 Gore Excluder limbs. The indication was always complex iliac anatomy. The primary technical success rate in this group was 89% (26 of 29 patients), with a primary assisted technical success rate of 100%. Mortality at 30 days was 0%. The mean follow-up was 19.4 months (range 2–64 months). Late mortality was 13.8% (4 of 29), with no aneurysm-related death. No graft limb occlusion or disconnection occurred during follow-up. No reintervention was needed in the hybrid endograft group. The use of a Cook Zenith body with Gore Excluder limb(s) in case of adverse iliac anatomy is feasible and showed no adverse effects at the midterm follow-up.