The INNOVATION study found that the rate of freedom proximal type I endoleaks and the rate of freedom from reintervention in patients who underwent endovascular aortic aneurysm repair (EVAR) with the Incraft (Cordis) device was, respectively, 100% and 95%, at three years. In this interview, CX Daily News speaks to Giovanni Pratesi (Florence, Italy)—who presented the data at CX yesterday—about Incraft and the three-year results.

How does the Incraft stent graft differ from other EVAR devices?

It is a new-generation stent graft system with unique features that have been specifically designed to overcome the limitations of current stent grafts. For example, the ultra-low profile integrated delivery system (14F OD) offers excellent navigational opportunities in challenging access vessels. Additionally, the micrometric deployment system allows for accurate placement—either at proximal and distal attachment site. Bilateral in-situ length adjustment, up to 3cm, permits you to customise every implant on the single patient anatomy. Therefore, the Incraft system, according to the “few-fits-most” concept, is able to cover a large spectrum of anatomies with only 23 product codes, four main bodies and 19 iliac limbs.

What are the main results of the INNOVATION study at three years?

The three-year results of the INNOVATION study have confirmed the very promising one- and two-year outcomes of the study. These data show, at three years, the device is associated with 100% freedom from type Ia and III endoleaks, stent-graft migrations, and device- or procedure-related major adverse events. They also show that the rate of limb patency is 97.8%, with only one case of limb occlusion. Other findings from the three-year data indicate that there is a significant reduction in mean aortic aneurysm diameter, up to 15 mm, compared with two-year data, a freedom from sac increase of 95.6% and freedom from stent fractures of 97.7%. Core lab analysis has identified two cases of aneurysm sac enlargement—both associated with a persistent type II endoleak—and one case of stent fracture, but these events did not appear to have any clinical consequences.

What other data were included in your presentation?

I specifically addressed endograft durability and anatomical preservation in my analysis of the Innovation study. Data from core lab analysis have confirmed the excellent stent graft stability that has already been observed during follow-up. A median proximal migration of 2mm was observed at three-year compared with the one-month computed tomography (CT) scan. The same result was achieved in terms of distal migration with a median change of 1.1mm and 2mm on the right and left side respectively, compared with the one-month CT scan.

Aortic neck diameter, neck angulation and iliac artery diameter, compared with one-month CT scan, were analysed at three years to review endograft influence on anatomic changes during follow-up. The observed 1mm proximal neck dilatation and 2mm iliac artery dilatation, combined with the 0.6 degree changes for infrarenal neck angulation and 2.4 degree for suprarenal neck angulation, confirmed the excellent stent graft conformability to the preoperative anatomy.

What were the main take-home messages from your presentation?

These data confirm the very promising earlier outcomes of Incraft stent graft system and add new evidence regarding its effectiveness in terms of anatomy preservation with a 100% freedom from both proximal aortic neck and iliac dilatation, and from proximal supra- and infrarenal aortic neck angulation changes.

Yesterday saw the beginning of the two-day CX Venous Workshop, in which delegates can enjoy expert demonstrations of a selection of the most interesting and important phlebological technologies currently in use. Now in its seventh year, the event continues to attract more and more delegates to its plethora of new and established technologies, and this year occupied its largest space ever on the Upper Level of the Gallery. The first day of the workshop largely focused on varicose vein treatment and superficial venous issues.

Ian Franklin (Imperial College, London, UK) is leading the workshop over both days, and has done since it first featured at the Charing Cross Symposium seven years ago. He explained, “I think it is important to provide a combination of the big plenary sessions in the hall and smaller interactive workshops like this one—not all techniques and discussions lend themselves the plenary environment. By providing these training stations and this small-group one-to-one teaching format, it means that people can interact in a much more informal, personal level.”

Over its seven years the workshop has grown and changed, keeping pace with the changing face of the vascular field. “The needs have changed,” Franklin commented. “When we first started doing this it was an office-based varicose vein course. Now it is far more than that. We have found that quite a lot of the techniques that people were hungry to learn at the beginning are ‘old hat’ now, so each year we offer new things. Now people are hungry to learn deep vein stenting, intravascular ultrasound, non-thermal techniques for treating veins, and so on. This year we have some completely new things that people will not have seen before.”

Given the quality of the Charing Cross faculty, such one-to-one interaction presents an exciting educational opportunity. “All of our faculty are well-known names and enthusiasts in their field. You can interact with them much better if you talk to them face-to-face rather than if they are up on a podium and you are down in the audience and asking the questions through a microphone. This way you can ask things you might not be able to go into in a lecture theatre.” Franklin added that these face-to-face interactions combine with practical experience, and delegates can “hold the kit in their hands, practice on the simulator and talk through tips and tricks with someone who has done it a lot before—you cannot do that in a lecture theatre.”

The workshop’s layout with multiple training stations also means that delegates can be efficient with their time, heading straight for those stations dealing with subjects they are unfamiliar with. “They do not have to sit through things they already know about, so they can make very efficient use of their time,” Franklin said.

The workshop features both established and new technology. One of the busiest stations yesterday was that of a well-established technology—foam sclerotherapy.  Simon Ashley (Plymouth, UK), was one of the trainers at the station. He spoke to CX Daily News during the workshop, and explained, “Personally it is the first time that I have been involved as a trainer, but I know that it has been running for a number of years and has grown increasingly popular—that is why so much space has been devoted to it.” As to why the station was so busy, Ashley noted that foam sclerotherapy “is a walk-in walk-out treatment that only takes about 20 minutes and there is no down time or restriction of activities afterwards. It is also very attractive for NHS and private practice because it is undoubtedly the most cost-effective treatment.”

In keeping with the Charing Cross Symposium’s passion for innovation, there was also a selection of new techniques and products on show. The Biolas station, exhibiting the company’s non-thermal ablation VariClose vein sealing system, was kept busy throughout the day by curious delegates. The company are attending their first ever Charing Cross Symposium, and chief medical officer, Yunus Çakiroĝlu, told CX Daily News “We are new this year, so I think a lot of people are wondering about our products and our company—they want to find out who we are and what we have at our station. The meeting is very exciting, and the workshop is a great way for the delegates to understand new technology.”

The workshop will continue today with a focus on acute deep vein thrombosis interventions, intravenous ultrasound and deep venous stenting, but still including ablation technologies for superficial veins. The stations open for delegates to visit will include: thermal (laser), thermal (radiofrequency ablation), non-thermal, practical training stations, valves, vascular ultrasound training simulator, venous malformations, pelvic venous imaging, pelvic vein embolisation, acute deep vein thrombosis, caval filters, follow-up protocols, air plethysmography, intravascular ultrasound and deep vein stenting.

Franklin expects the Upper Gallery to be just as busy as it was yesterday thanks to the planning of this year’s programme. He said, “We have made an effort to separate the days this year, with Wednesday focusing more on superficial techniques. On Thursday we are going to have a big focus on deep vein stenting, deep vein thrombosis treatments, pelvic vein embolisation and intravascular ultrasound. These are all quite new for us and should attract a new group, so I expect it to be busy tomorrow as well.”

According to Janet Powell, Imperial College London, UK, the highest risk factors for rupture of abdominal aortic aneurysms (AAA) are female gender, smoking, increasing age and mean arterial pressure, but there are still few useful indicators of how to manage screen-detected aneurysms to stop them enlarging. Powell put forward this view during yesterday’s Abdominal Aortic Controversies Main Programme which explored epidemiology, indications and medical management of abdominal aortic aneurysms.

In trying to work out what makes aneurysms grow, Powell said that mostly the “mundane” cardiovascular risk factors have been looked at—alcohol, diet, obesity, smoking, medicines taken, exercise taken.

Turning to the existing and ongoing randomised trials that provide evidence for growth factors, Powell pointed out three trials already completed and without a positive result—AAA:STOP, PHAST and AORTA.

“Even in 2015, it is quite difficult to find information about trials because some trials still remain unregistered. Large epidemiological studies have mainly shown us about the risks for developing aneurysms, but the focus has been on baseline risk factors, not aneurysm progression,” she said.

Powell referred to RESCAN, a large international project primarily with the purpose of looking at optimal surveillance intervals for small aortic aneurysms, which was an individual patient data meta-analysis of small aneurysms, their growth and rupture in more than 15,000 persons.

“As we all know, growth rate increases with aortic diameter—just 1.34mm a year for the smallest aneurysms and 3.63mm when it comes to 5cm aneurysms—with exactly the same growth rate between men and women,” she pointed out.

When it comes to smoking, Powell maintained that the data are remarkably consistent that it increases aneurysm growth rate but that the effect is modest. Similarly, the effect of diabetes to slow or reduce the aneurysm growth rate is very consistent, but small.

“So we identified out of the available baseline data we had only two factors in these 15,000 patients that influenced growth rate and both effects were relatively modest—smoking increases, diabetes decreases. Cholesterol, blood pressure, statins, anti-hypertensive drugs and aspirin had no effect, and the year of enrolment [1985–2008] had absolutely no effect either. Disappointing,” Powell stated.

Rupture rates

Even though rupture of small aneurysms is not common, findings were more informative. RESCAN showed that the smallest of aneurysms take eight or more years before the risk of rupture is anything substantive, but as the diameter increases, so does the risk of rupture. But even for a 5cm aneurysm, it is more than year before risk of rupture exceeds 1%.

Powell pointed to some strong associations with factors that increase rupture rates. “Most notable, the fact that in women, there is fourfold increase in rupture rates vs. men. With smokers there is a twofold increase, with a far bigger effect on rupture than on growth. Mean arterial pressure increases growth rate, as does age. The older you are, the more likely your aneurysm is to rupture for any given diameter. So we cannot have any of this ageism, we need to treat aneurysms in older people too,” Powell maintained.

In the EVAR 2 trial, and subsequently reproduced in other papers, Powell observed that aortic neck length was associated with rupture and the shape of the aneurysm might have mattered, and a long neck was associated with relative protection from aneurysm rupture.

“Where are we in 2015? For rupture, there are some strong factors increasing risk: female gender, smoking (which we can do something about), increasing age, higher mean arterial pressures (we could have more effective blood pressure control), and the fact that a long aneurysm neck could just be protective. However, for growth, the effects that we have identified are modest: smoking, which increases it, and diabetes, which is protective,” Powell said.

She re-stressed that both of those growth effects are modest, adding that, “unfortunately this leaves us in a position that as yet we have few useful indicators of how to manage screen-detected aneurysms to stop them enlarging other than the old classic that was used for intermittent claudication—stop smoking and possibly keep walking.”