Physician-modified Endografts on Trial

The case for physician-modified endografts in urgent settings was made by Nikolaos Tsilimparis, Professor and Head of Vascular Surgery at the University Hospital of Munich, Germany. A general, vascular and endovascular surgeon, Professor Tsilimparis spoke about an important multicenter trial on physician-modified endografts in complex aortic surgery.

Recalling his early career, Professor Tsilimparis trained in the US, from Rochester and Minnesota to Atlanta, in physician-modified endografts. “I got to see the technique for manufacturing them, and ever since, I have used them often as needed in my practice,” he told LINC Today.

Bringing his knowledge back to Europe, Professor Tsilimparis now has one of the largest practices. His group recently looked at outcomes from physician-modified endografts at centers of excellence in the US and Europe. “With around 1,300 patients, both elective and urgent cases, it is the largest series on physician-modified endografts that has ever been collected,” he explained.

Such endografts are important in urgent situations, explained Professor Tsilimparis. Today, the only alternative to surgeon-modified endografts is custom-made devices manufactured by companies specifically for patients. However, these custom-made devices require a manufacturing time of up to 3 months, restricting them to elective settings. Furthermore, manufactured endografts are not available in all countries. “In the US, a lot of physicians do not have access to manufactured endografts,” he said. “So, they have to go a step back and use physician-modified endografts.”
 
Interestingly, guidelines on the use of physician-modified endografts have changed. Europe approved the use of this technique in urgent situations, but usage is still relatively lower than it could be.

Professor Tsilimparis outlined the first unpublished data from the trial, which comprised 1,274 patients. Complex abdominal and thoracoabdominal aortic aneurysms each accounted for approximately half of the cases. The endpoints were mortality and morbidity after the implementation of fenestrated or branch endografts in both complex aortic aneurysms and thoracoabdominal aortic aneurysms.

A meta-analysis¹ carried out previously by Professor Tsilimparis’ group already evaluated this technique, yet the results from this more recent study were a little unexpected. “The technical success in both groups was very high,” said Professor Tsilimparis, reaching 94% in both elective and urgent cases, with a 30-day mortality that reached 4% in the elective group, 7.6% in symptomatic patients and 12.7% in ruptured aortic aneurysms. “This was very surprising,” he added. “These are excellent results for physician-modified grafts produced in these centers of excellence.”

The durability of repair was also evaluated in terms of endoleaks and target vessel stability, as well as long-term results. “But again, we did not really expect that the results were going to be as good as the ones that we have from custom-made devices,” he said. “We were a little surprised that there were not huge differences in terms of endoleaks.”

These positive results were probably attributed to the fact that the centers are very experienced at modifying endografts. “We’re talking about high-volume centers too,” Professor Tsilimparis clarified, “so it is important also to keep in mind that these results are probably not quite reproducible in every center that will start using physician-modified endografts.”

There are different approaches to modification, which Professor Tsilimparis also discussed. His group will typically perform measurements on a computed tomography scan and then transfer them to the graft. “Another option is to use a plastic sheet which you have marked them on, put it around the graft and do the fenestrations,” he explained. Three-dimensional models can also be used.

The results of this study might catalyze approaches in this area, stressed Professor Tsilimparis. “With this study we are seeing that the results—both in elective and urgent settings—are quite satisfactory,” he commented. “A technique that has always been around but underused because of regulatory issues is now finding a place again.”

The group was not able to study in detail the difference between modification techniques, he noted. “We didn’t prove a difference, but a lot of groups are working on that.” Additionally, companies are starting to consider how to standardize the production of these physician-modified endografts. “If companies jump on the bandwagon, it might cause a rapid acceleration of the technique,” he predicted. “And that is something that is quite exciting.”

There may also be ramifications beyond urgent settings, said Professor Tsilimparis: “Such endografts have not been accepted in the elective setting, but that might change, at least in the countries where the custom-made devices are not yet widely available.”

Secondly, with standardization, there may be more incentive to ensure such endografts can be used beyond centers of excellence. “While it’s not an easy technique, it will require appropriate training,” he reasoned. “We can make it accessible to the general vascular surgery community in order to make it more widely used.”

He concluded: “It appears to be among the best options that we have to treat urgent cases, and if standardized enough, why not even in elective cases?”

Reference

1. Gouveia E Melo R, Fernández Prendes C, Caldeira D, et al. Systematic review and meta-analysis of physician modified endografts for treatment of thoraco- abdominal and complex abdominal aortic aneurysms. Eur J Vasc Endovasc Surg. 2022;64(2-3):188-199.