1, first of all, correct a statement, in vascular surgery, we call it endovascular treatment, not interventional treatment, there is an essential difference between the two, so you should go to a hospital with vascular surgery for regular treatment of this disease. 2, a, internal iliac aneurysm has the possibility of rupture, which can be life-threatening; b, arteriovenous fistula, especially the arteriovenous fistula of the middle vessels, will increase the amount of blood returned to the heart and increase the burden on the heart, which may lead to heart failure. 3. Regarding the treatment, my opinion is that endovenous treatment is preferred because: a. It is in the presacral plexus, and after pelvic surgery, reopening the surgery will easily cause damage due to adhesions. b. It is difficult to directly damage the femoral nerve by puncture and the possibility of hematoma compression is higher. This can be avoided by careful operation. 4. There are two types of endoluminal treatment options: a. If the fistula is located near the beginning of the internal iliac artery, the fistula tract can be directly embolized with a spring ring or the fistula can be closed with a laminated stent placed directly into the internal iliac. Advantages: preservation of the internal iliac artery. Disadvantages: easy recurrence when closure is incomplete. b. If the fistula is poorly positioned, the internal iliac artery is embolized with a spring steel coil and then the external iliac artery is placed with a laminated stent to close the internal iliac. Advantages: the efficacy is more precise. Disadvantages: the closure of the internal iliac artery may have an impact on sexual life. The above is only a suggestion based on your limited information. The final plan should be based on the imaging data.