EXCeL Registry Post-Market Study on Angulated Necks

The latest results from the important EXCel registry were released on Wednesday morning by Marc van Sambeek, a vascular surgeon at the Catharina Hospital in Eindhoven, the Netherlands, and professor of Application of Engineering in Vascular Surgery and Endovascular Therapy.

Dr. van Sambeek outlined the 6-month, 1-year and 2-year data from the EXCeL registry, a post-market registry study for the Excluder Conformable AAA Endoprosthesis (Gore).

The endograft is important because of its angular delivery system, said Dr. van Sambeek. “The advantage is that you can angulate the delivery system so that the device can be positioned more precisely in situations where there is an angulated neck.” He explained that if there is an infrarenal aneurysm and when the endograft is deployed, due to the stiffness of both the guide wire and the delivery system, only one position is possible. “And that means that most likely in this situation, you cannot reach the optimal position of the endograft in the infrarenal neck.”

For example, the restrictions may mean the device is deployed perpendicular to the delivery system. “Then you do not cover part of the infrarenal neck,” he said. “If it's angulated properly, there is a high chance that you get a much better position so you can change the angulation of the delivery system to the optimal position.” Ideally the device can be positioned just below the left and the right renal artery.

The post-market registry was designed to study this adaptation, which will ultimately include 150 patients at eight centers throughout Europe—from the Netherlands to Spain and the UK. Just before LINC, the number of patients participating in the study was around 135. “Patients included in the registry are core-lab assessed, which identifies how their aneurysms should be classified,” Dr. van Sambeek said.

Importantly, within the EXCeL registry, the participating centers decided to include many different patients.  “They were free to adhere to the instructions for use (IFU), or go outside the IFU, just like in a real-world situation,” he said. Some patients had even been treated in the extreme range. “We can say that approximately 90% of all the cases that are in the registry are within the IFU as set by Gore,” he said. “Around 10% of the patients treated were outside the IFU and we have two patients in the study who are considered extreme. So it's a mixed population.”

He added: “We don't see any Type 1 endoleaks. The technical success is relatively high. And we had neck lengths ranging from 4 to 60 mm and angulations ranging from 5° all the way up to 106°.”

Dr. van Sambeek showed data for the first time at LINC. “The results so far are looking very good, especially at 30 days,” he said. “But it gets interesting at the 1-year follow-up of approximately 50 to 55 patients,” he said.  “And in that group of patients we did not see any migration or new Type 1 or Type 3 endoleaks.”

In addition, almost 20% of the patients have been assessed after 2 years by now. Dr. van Sambeek said data for those patients shows no migration or Type 1 endoleaks. He looks forward to seeing the results of more patients from the cohort at 2 and then 3 years. “In the end we need a 3-year follow-up for all the patients and then we can come up with a definitive conclusion,” he said. “But actually, it is looking really good so far. Very promising results.”

In addition to maintaining the EXCeL registry, Dr. van Sambeek explained that his group is now performing a biomechanical analysis of the infrarenal necks using dedicated software that is able to measure dimensions on computed tomography scans. “We will calculate the performance of the endograft,” he explained. “We can calculate the area of potential acquisition and then after implantation we're going to calculate again; we want to know how much of that potential acquisition has been actually covered by the endograft to see whether this device is indeed optimizing the acquisition.”  In other words, they are quantifying just how much coverage the graft can achieve using the angulation possible.

The data so far looks extremely promising. “With a new device EVAR is continually evolving as a treatment option for AAA,” said Dr. van Sambeek. “A new generation of devices can extend the applicability of EVAR, so that more patients can be treated by endovascular means and the necessity for open surgery will decrease over time.”

He concluded: “Any new generation of device makes it easier and better to treat the patients and allows a larger percentage of the patients to be treated using endovascular techniques.”