Fenestrated EVAR has been in use in the United Kingdom for over a decade and early results were published in Jun 2012. Branched EVAR
Thoracoabdominal aortic aneurysms (TAAA) involve the aorta in the chest and abdomen. As such, major branch arteries to the head, arms, spinal cord, intestines, and kidneys may originate from the aneurysm. An endovascular repair of a TAAA is only possible if blood flow to these critical arteries is preserved. Hybrid procedures offer one option, but a more direct approach involves the use of a branched endograft. However, the complex anatomy associated with the supra-aortic vessels is particularly difficult to accommodate with branched endograft devices. Dr. Timothy Chuter pioneered this approach, with a completely endovascular solution. After partial deployment of the main body of an endograft, separate endograft limbs are deployed from the main body to each major aortic branch. This procedure is long, technically difficult, and currently only performed in a few centers. When the aneurysm begins above the renal arteries, neither fenestrated endografts nor "EndoAnchoring" of an infrarenal endograft is useful (an open surgical repair may be necessary). Alternatively, a "branched" endograft may be used. A branched endograft has graft limbs that branch off of the main portion of the device to directly provide blood flow to the kidneys or the visceral arteries. Hybrid procedures
On occasion, there is inadequate length or quality of the proximal or distal aortic neck. In these cases, a fully minimally invasive option is not possible.
The first device was simple, according to Parodi: "It was a graft I designed with expandable ends, the extra-large Palmaz stent, a Teflon sheath with a valve, a wire, and the valvuloplasty balloon, which I took from the cardiologists." Parodis first patient lived for nine years after the procedure and died from pancreatic cancer. The first EVAR performed in the United States was in 1992 by Drs. Frank Veith, Michael Marin, Juan Parodi and Claudio Schonholz at Montefiore Medical Center affiliated with Albert Einstein College of Medicine.The modern endovascular device used to repair abdominal aortic aneurysms, which is bifurcated and modular, was pioneered and first employed by Dr. Timothy Chuter while a fellow at the University of Rochester. The first clinical series of his device was published from Nottingham in 1994. The first endovascular repair of a ruptured abdominal aortic aneurysm was also reported from Nottingham in 1994.By 2003, four devices were on the market in the United States. Each of these devices has since been either abandoned or further refined to improve its characteristics in vivo. Special populations
Women
Women are known to have smaller aortas on average than men, so are potential candidates for AAA treatment at smaller maximum aneurysm diameters than men. Transplant candidates
As immunosuppressive medications are known to increase the rate of aneurysm growth, transplant candidates are AAA repair candidates at smaller maximum aneurysm diameters than the general population. Other animals
Due to the expense associated with EVAR stent-graft devices and their specificity to human aortic anatomy, EVAR is not used in other animals.