Sounds like your father has an aneurysm. At the size you report, the situation starts to become dangerous. And, actually, there are two ways to take care of the problem: open surgery, which is the most uncomfortable for the patient but the supposed "gold standard" of treatment, and stenting (placing a flexible tube into the aorta where the swelling (aneurysm) is). The latter is the least uncomfortable solution: involves a couple of nights in the hospital and back to running around as usual in a few weeks. But if the area between the aneurysm and the renal arteries is too slight for a conventional commercially-made ordinary stent, then you need to go to Cleveland Clinic (which uses commercially made fenestrated stents from Australia), Mayo Clinic (surgeon-modified stents), Emory in Atlanta (talk to Dr. Ricotta, from Mayo, adept at what they call surgeon modified "fenestrated" stents, or to the University of California, San Francisco. About 50 percent of folks with aortic aneurysms need the fenestrated (windowed) stent procedure but most vascular surgeons cannot do that procedure. For sure something has to be done for your father, so if he is afraid of surgery or complications, get him to one of the places I mentioned (not that the procedure is without risks: they all have risks). Good luck!
The most important thing is for your father to visit a VERY EXPERIENCED surgeon. That is the key.
The consensus of the medical community:
Surgical outcome and risk of procedure:
The risk of death or serious complications from aortic valve replacement is typically quoted as being between 1-3%, depending on the health and age of the patient, as well as the skill of the surgeon. Older patients, as well as more fragile ones, are sometimes ineligible for surgery because of elevated risks.
Hospital stay and recovery time:
Immediately after aortic valve replacement, the patient will frequently stay in a cardiac surgery intensive care unit for 12-36 hours. After this, the patient is often moved to a lower-dependency unit and then to a cardiac surgery ward. Total time spent in hospital following surgery is usually between 4 and 10 days, unless complications arise. Common complications include heart block which typically requires the permanent insertion of a cardiac pacemaker.
Recovery from aortic valve replacement will take 1-3 months if the patient is in good health. Patients are advised not to do any heavy lifting for 6-8 weeks following surgery to avoid damaging the sternum (breast bone) while it heals
Thanks for your question, and I wish your father the best.