Figure 3.

Endoleaks:

Type I: These endoleaks are caused by leakage from the proximal anchoring (type Ia) or distal anchoring (type Ib) and require treatment. They can be caused by incorrect prosthesis selection with insufficient oversizing of the prosthesis, implantation errors, or secondary migration of the stent prosthesis.

Type II: The aneurysm is further perfused via lateral branches (e.g. the lumbar artery or inferior mesenteric artery). This is the most common type of endoleak and is observed in up to 15% to 20% of cases at the first checkup following prosthesis implantation. Type II endoleaks initially require only monitoring but must be treated if checkups reveal an increase in aneurysm diameter. In many cases, the arteries close spontaneously.

Type III: The aneurysm sac is further perfused by the overlap zones of individual stent prosthesis components. This can be closed using balloon angioplasty or stent angioplasty of the docking zone.

Type IV: Blood can escape into the aneurysm sac through stent material. This type of endoleak is now rare as a result of improved stent prostheses.

Type V: Checkups reveal an increase in aneurysm diameter, but no contrast substance can be detected outside the stent prosthesis. This is thought to be caused by a remaining increase in pressure following endovascular aneurysm repair.