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.

Endovascular repair of inflammatory abdominal aortic aneurysms.

PURPOSE: To report a single-center experience with endovascular repair of inflammatory abdominal aortic aneurysm (IAAA), with particular attention to the fate of the aneurysm sac, perianeurysmal fibrosis (PAF), and renal function. METHODS: A retrospective review of 350 patients undergoing endovascular aortic aneurysm repair during a 7-year period at University Hospital, Nottingham, identified 14 (4%) cases of IAAA confirmed either on preoperative spiral computed tomography (CT) or at laparotomy in attempted open aneurysm repair. All data were reviewed from a prospectively maintained database, hospital notes, and serial CT studies. RESULTS: Endovascular repair was successfully completed in all 14 IAAA patients, but 2 (14%) died in the perioperative period. One patient referred from another center was lost to imaging follow-up, leaving 11 patients who were followed for a mean 29 months (range 1-73). All 11 IAAAs remained excluded, but 1 patient required a secondary transabdominal intervention for a type III endoleak. There was no CT evidence of PAF progression in any patient. Postoperative renal complications were not encountered where there had been none preoperatively. CONCLUSIONS: IAAA may be successfully excluded by the endovascular technique, and EVAR is particularly useful where open repair has failed. The impact of endograft placement on perianeurysmal fibrosis is less clear. In this study, there was no suggestion that the degree of PAF worsens following endovascular repair.

Color duplex ultrasonography of the superior mesenteric artery after placement of endografts with suprarenal stents.

After endovascular repair of abdominal aortic aneurysm with endografts with suprarenal stents, the proximal uncovered stent may cross the origin of the superior mesenteric artery. Effects on splanchnic circulation are unknown and may include development of stenosis at the vicinity of the stent. The criteria of high-grade superior mesenteric artery stenosis using color duplex ultrasonography have been previously reported. The purpose of this study is to examine the incidence of high-grade superior mesenteric artery stenosis in patients with endografts with suprarenal stents using color duplex ultrasonography. Candidates for the study were patients who had placement of an aortic endograft with a suprarenal stent and were able to undergo ultrasonography of the superior mesenteric artery. After reviewing computed tomography scans, patients who had the origin of the superior mesenteric artery crossed by the suprarenal stent underwent color duplex ultrasonography of this vessel. Presence of turbulence or narrowing of the superior mesenteric artery, or a peak systolic velocity greater than 2.75 m/sec, or an end-diastolic velocity greater than 0.45 m/sec were considered significant for the presence of high-grade superior mesenteric artery stenosis. There were 24 patients (21 males, three females), median age 71 years (range, 59-83). The suprarenal stent was crossing the superior mesenteric artery in 17 of 24 patients (71%). Color duplex ultrasound was technically successful in 13 of 17 (76%). The test was performed after a median follow-up of 9 months (range, 3 days to 34 months). No patient had evidence of turbulence or narrowing of the superior mesenteric artery during ultrasonography. The median peak systolic velocity was 0.92 m/sec (range, 0.53-1.21 m/sec). No patient had peak systolic velocity greater than 2.75 m/sec. The median end-diastolic velocity was 0.10 m/sec (range, 0.09-0.14 m/sec). No patient had end-diastolic velocity greater than 0.45 m/sec. Color duplex ultrasonography did not demonstrate the presence of high-grade superior mesenteric artery stenosis during early follow-up of patients with endografts with suprarenal stents. Longer follow-up of larger series of patients is needed to determine the long-term effects of suprarenal stents on splanchnic circulation.

Stent-graft migration after endovascular repair of abdominal aortic aneurysm.

PURPOSE: To report the incidence of graft migration in patients after endovascular repair of abdominal aortic aneurysms (AAA) and assess the significance of neck diameter changes in patients with and without suprarenal stent implantation. METHODS: The medical records and imaging studies of 176 consecutive patients (175 men; median age 71 years, range 48-88) who had endovascular AAA repair with the Nottingham aortomonoiliac system were reviewed. The following parameters were recorded: preoperative neck diameter and length, presence of intraoperative and late graft migrations, time to onset of late migration, length of late migration, and neck diameter changes in patients with documented late graft migration. The patients were divided into 2 groups based on the placement of an endograft with or without suprarenal bare stent fixation. Median follow-up was 15 months (range 1-48). RESULTS: There were 15 (8.5%) graft migrations (6 intraoperative and 9 late). Of those, 14 (10.9%) were in the 128-patient infrarenal fixation group and 1 (2.1%) in the 48-patient suprarenal stent group. Median neck diameters on preoperative and postoperative computed tomography scans in patients with late migration were 22.2 mm and 23.0 mm, respectively (p>0.05). The median time to graft migration was 14 months after the original operation (range 6-36). CONCLUSIONS: Distal device migration occurred frequently with the Nottingham system. Late graft migration was not associated with neck enlargement. Endografts with a suprarenal stent may have a decreased incidence of graft migration.