Fenestrated Anaconda achieves high procedural success in complex aneurysms

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Nick Burffitt
Nick Burffitt

The Fenestrated Anaconda custom AAA Stent Graft System (Vascutek) achieves high procedural success in short-necked abdominal and pararenal aortic aneurysms, according to results from UK and Dutch experiences presented at the VEITHsymposium in November.

Nick Burfitt, consultant interventional radiologist, Imperial College Healthcare NHS Trust, London, UK, presented the short- and medium-term analyses of the first 100 UK cases.

“One of the main advantages of using the Fenestrated Anaconda stent graft is that it has a repositionable body that allows for accurate initial deployment and is repositionable throughout the procedure, and can be tailor-made to suit challenging anatomies. It works well in angulation, is also good in aortic stenosis and the fenestrations can be of any size and position,” he said.

The graft has zero columnar strength, is flexible and allows for brachial access through an open proximal design.

“The device was first implanted in June 2010 and there have been 431 implants to date in Europe, Canada and Australia. A registry, the Vascutek Global Registry, for data collection that is prospective, multicentre and web-based is available at www.fenestratedanaconda.com,” Burfitt reported.

“The UK data from the registry show that there was a high level of procedural technical success and an acceptable 30-day mortality (4%) that is comparable with the results of the GLOBALSTAR registry. In the analysis of the first 100 cases, we have seen good short- and medium-term results with regard to aneurysm exclusion, sac size, migration and graft and visceral stent patency,” Burfitt said at the VEITHsymposium (19–23 November, New York, USA).


He noted that there had been 138 implants made in 15 UK centres, of which 108 had been included in the registry. There were follow-up data for 67 patients at one year, 23 at two years and three patients at the three-year mark.

Burfitt noted that the custom-made stent graft had been used to treat short-necked infrarenal aneurysms through to limited type IV thoracoabdominal aortic aneurysms and they were predominantly used with two or three fenestrations.

 

Patient demographics

 

In the UK data, the mean age of patients was 75 years (range 56–87). The mean size of the abdominal aortic aneurysm was 63mm (range 45–94mm). There were 82 men and 18 women treated with the stent graft.

With regard to the American Society of Anesthesiologists (ASA) physical status classification, none of the patients were grade I,  22% were grade II , 66% were grade III, 12% were grade IV and none were grade V. Fifty four per cent of patients were fit for open repair.

The researchers had 100% technical success (no aborted procedures), over 99% target vessel cannulation (one failure of 238 target vessels) and no conversion to open repair.

At the end of the procedure, there were five cases of type I endoleak, 13 instances of type II endoleak and six instances of type III endoleak. At 30 days or discharge, there were two instances of type I endoleak, 18 instances of type II endoleak and two instances of type III endoleak.

There were four deaths at 30 days; one from myocardial infarction, one from mesenteric ischaemia due to mesenteric artery dissection, one from multi-organ failure and one stroke.

Burfitt made the point that the mortality results from the first 100 UK patients were comparable to those of the GLOBALSTAR UK retrospective study in which 14 experienced centres (>10 FEVARs) carried out 318 FEVAR cases in the period 2007–2010. “GLOBALSTAR had a 30-day mortality of 4.1%. In the Fenestrated Anaconda first UK 100 cases, where 41% of cases were carried out in inexperienced centres, the current overall UK Anaconda FEVAR 30-day mortality is 3.7% (5/135),” he said.

At the one-year follow-up, there were 67 patients and data were available for 50. There were two deaths; one due to myocardial infarction and the second due to a type B dissection rupture. There were two renal stent occlusions (>98% patency overall), one iliac limb occlusion, one common femoral artery occlusion. There was no device migration, no type I or III endoleak, the sac size remained stable or decreased in 49 (98%) cases. There was an increase in sac size in one patient (2%).

At the two-year mark, there were 23 patients and data were available for 18. There was one death, one renal stent occlusion (96% patency). There was one graft infection for which an explant has been planned, no device migration, no type I or III endoleak. The sac size remained stable or decreased in 17 patients (94%). It increased for one person (6%). One case of type II endoleak was treated with Onyx embolization.

At the three-year follow-up, there were three patients at follow-up and data were available for two (one patient refused follow-up). There were no further deaths, no migration, no endoleak and sac size had decreased.

Dutch experience

Clark Zeebregts, professor of Vascular Surgery, University Medical Center Groningen, Groningen, The Netherlands, reported on the Dutch experience with 25 patients using the Fenestrated Anaconda stent graft.

“Twenty two men and three women were treated in eight institutions between May 2011 and September 2013,” he said.

The median patient age was 73±7.1 year and median aneurysm size 64± 8.8mm. There were 23 juxtarenal and two infrarenal aneurysms with short necks.

There were three patients treated with a graft with one fenestration, 15 who were treated with a graft with two fenestrations, five who were treated with a graft with three fenestrations and two with grafts that had four fenestrations.

“We had acceptable short-term results with Fenestrated Anaconda. We need to still exercise caution because it is a procedure that is effective in a carefully selected population and remains a complex procedure. Long-term results are needed,” Zeebregts said.

The early results showed that 94.6% (53/56) were successfully cannulated. The in-hospital mortality was 4% (1/25). There were three type I endoleaks and seven type II endoleaks on completion angiography. “All these resolved after one month, even the type I endoleaks,” Zeebregts said.

The median follow-up was 11 months (1–29 months); one patient died after four months due to stroke. There were no abdominal aortic aneurysm ruptures, aneurysm-related deaths or further reinterventions.

Zeebregts noted that there were some limitations with the Fenestrated Anaconda graft that were due to sizing, the fact that no fixed branched devices are available yet, folding at aortic rims (for which some tips and tricks are useful) and due to the incidence of mainly temporary type I endoleaks. “The incidence of bowel ischaemia has decreased with growing experience with the device,” he added.