Development of off-the-shelf stent grafts for juxtarenal abdominal aortic aneurysms.

INTRODUCTION: The use of EVAR for more complex aneurysm anatomy has become more widespread over the past decade. Fenestrated and branched stent grafts for the visceral and iliac segment show promising short- and midterm outcome and these procedures have become routine in many vascular centers. However, at present, such grafts are customized to the individual patient and planning and manufacturing leads to significant treatment delay subjecting the patients to the risk of rupture during the waiting period. The purpose of this report is to describe the first experience in treating juxta/suprarenal aneurysms using the first version of a new fenestrated stent graft MATERIAL AND METHODS: A fenestrated device was designed with two renal fenestrations, an SMA fenestration and a scallop for the coeliac artery. The renal arteries were designed with an inner 6 mm fenestration and an outer 15 mm diameter creating a dome to allow renal artery catheterization for a range of renal artery distribution. Seven patients with complex visceral artery anatomy were treated with customized stent grafts containing these pivot renal fenestrations. RESULTS: Technical success was uniform with 100% target vessel catheterization and 0% 30-day mortality. In one case, the graft was displaced slightly during delivery resulting in a renal artery stent occlusion at 2 months postoperatively. CONCLUSIONS: The development of a modified fenestrated device has shown this to be feasible and it has the potential to reduce the need for extensive preoperative graft customization and establishing a true off the shelf platform for juxta- and suprarenal AAA.

Sizing fenestrated aortic stent-grafts.

INTRODUCTION: Fenestrated aortic stent-grafts are increasingly being used to treat patients with juxtarenal abdominal aortic aneurysms (AAA). Sizing of these stent-grafts is critical to ensure success and requires detailed expert assessment of aortic morphology. At present little is known about how sizing of these stent-grafts varies between observers and the necessary tolerances involved to ensure a successful procedure. METHODS: CT scans of 19 consecutive patients with juxtarenal aortic aneurysms that underwent successful endovascular repair with fenestrated stent-grafts were selected. Sizing of fenestrated aortic stent-grafts was performed independently by four experienced endovascular surgeons and results were compared. Data from the stent-graft manufacturer was available for comparison in 12 cases. RESULTS: All observers agreed on the number of fenestrations; 16 devices had 3 fenestrations and 3 had 4. The overall inter-observer measurement error for all target vessel orientation was ± 12.6° (10.8-14.4 95% CI), and for distance between target vessels ± 5.3 mm (4.4-6.2 95% CI). The median difference in internal stent-graft diameter was 1 stent size. Agreement on fenestration type ranged from (84-95%). Comparison was performed with the manufactured stent-graft in 12 cases. The overall mean difference of target vessel orientation between the manufactured devices and the four observers was -1.3° (SD ± 6.9,-3.8-1.2 95% CI). There was less agreement between observers and device manufacturers on body and limb lengths and distal limb diameters. CONCLUSIONS: There was generally a high level of agreement between experienced endovascular surgeons in sizing the fenestrated stent component. There were differences in component lengths but these could have been accommodated by varying the degree of overlap between components.

EVAR of aortoiliac aneurysms with branched stent-grafts.

INTRODUCTION: Branched iliac stent-grafts (bSG) have recently been developed in order to preserve internal iliac artery (IIA) flow in patients with aneurysmal or short common iliac arteries. The aim of this study is to evaluate a single-center experience with bSG for the IIA. METHODS: Twenty-two male patients (70 (IQR 65-79) years old) underwent EVAR with 23 bSG (1 bilateral repair) between September 2002 and August 2007. Median AAA diameter was 52 (37-60) mm while common iliac diameter on the side of the bSG was 34 (27-41) mm. Two in-house modified Zenith SG and subsequently 21 commercially available bSG (18 Zenith Iliac Side and 3 Helical Branches) were used. Follow-up (FU) included CT at one month and yearly thereafter. Data was prospectively entered in a database. RESULTS: Primary technical success was 91% (21 bSG). Median FU duration was 20 (8-31) months. One patient (5 %) died after discharge from acute myocardial infarction on day 13. Another patient died 30 months after EVAR of an unrelated cause. The overall bSG patency was 74% due to 6 branch occlusions (2 intraoperative and 4 late). All patients with patent bSG were asymptomatic. Three occlusions were asymptomatic findings on CT, while the other three developed claudication (two patients with contralateral IIA occlusion and one with simultaneous occlusion of the external iliac). One patient (5%) developed an asymptomatic type III endoleak at 1 month and was successfully treated with a bridging SG. Overall, four patients (18%) required reinterventions (1 bilateral stenting of the external iliac arteries, 1 external and 1 internal SG extensions and 1 femoro-femoral cross-over bypass). Nine out of 16 patients (56%) with CT-FU>/=1 year had shrinking aneurysms. There were no postoperative aneurysm expansions. CONCLUSIONS: EVAR of aortoiliac aneurysms with IIA bSG is a good alternative to occlusion of the IIA in patients with challenging distal anatomy.

Remodeling of the thoracic aorta after stent grafting of type B dissection: a Swedish multicenter study.

AIM: Endovascular repair of complicated type B dissections has evolved as a promising alternative to open repair. Previous studies have indicated that continued false lumen flow is a predictor of continued aortic dilatation and risk of rupture during follow-up. This multicenter study was conducted to analyze the postoperative changes of the false lumen after endografting of complicated type B dissections. METHODS: All patients treated with endovascular stent grafts for thoracic type B dissections at 5 major Vascular Centers in Sweden were identified through local databases. Review of charts and all available pre- and postoperative CT scans were performed to identify demographics, indications for repair as well as postoperative changes of the aorta and false lumen. RESULTS: A total of 129 patients treated for type B dissections between 1994 and December 2005 were identified. Median radiological follow-up was 14 months. Fourteen patients died perioperatively leaving 115 patients available for analysis. Seventy-four of these had CT imaging of sufficient quality for morphological analysis. The vast majority of acute patients were treated for rupture or end-organ ischemia whereas most chronic patients were treated for asymptomatic aneurysms. In 80% of patients, the false lumen thrombosed along the stent graft but it remained perfused distal to the stent graft fixation in 50% of patients. Only 5% of patients presented with aortic enlargement of the stent grafted area when adequate proximal sealing was achieved. The distal, uncovered aorta displayed expansion in 16% of patients. CONCLUSIONS: The stent grafted thoracic aorta after type B dissection appears to be stabilized by covering the primary entry site with a stent graft in the majority of both acute and chronic dissections. The uncovered portion of the aorta distal to the stent graft, however, remains at risk of continuous dilatation. Stent grafting for complicated type B thoracic dissections seems to be a treatment option with reasonable morbidity and mortality even though the incidence of severe complications is still significant.

The use of endoanchors in repair EVAR cases to improve proximal endograft fixation.

AIM: The aim of this paper was to evaluate short-term outcome of the use of endoanchors to secure the primary migrated endograft and additional extender cuffs to the aortic wall in patients with previous failed endovascular aortic aneurysm repair. METHODS: Consecutive patients who needed proximal repair of a primary failed endograft due to migration (with or without type IA endoleaks) were treated with endoanchors, with or without additional extender cuffs. Data of this group were prospectively gathered in vascular referral centers that were early adopters of the endoanchor technique. Preprocedural and periprocedural data were prospectively gathered and retrospectively analyzed. Follow-up after endoanchor placement consisted of regular hospital visits, with computed tomography or duplex scanning at 1, 6, and 12 months. RESULTS: From July 2010 to May 2011, 11 patients (8 men), mean age 77 years (range, 59-88 years), were treated with endoanchors for a failed primary endograft (2 Excluder endografts, 1 AneuRx endograft, and 8 Talent endografts) due to distal migration of the main body, with or without type IA endoleak. Revision consisted of using endoanchors to secure the body of the primary endograft to the aortic wall to avoid persistent migration. Most patients had additional proximal extender cuffs with suprarenal fixation, which were secured with endoanchors to the aortic wall and in some patients also to the primary endograft. A median of 6 endoanchors were implanted. All endoanchors were positioned correctly but one. One endoanchor dislodged but was successfully retrieved using an endovascular snare. During a mean follow-up of 10 months (range, 3-18 months) no endoanchor-related complications or renewed migration of the endografts occurred. Two patients underwent repeat intervention due to persistent type IA endoleak during follow-up. CONCLUSION: The use of endoanchors to secure migrated endografts to the aortic wall is safe and feasible and might help to overcome persistent migration of primary failed endografts. In combination with the use of sole extender cuffs the majority of proximal EVAR failures can be solved.