In 2004 my best friend dropped dead 10 days post-op. She died of a sudden aneurysm.
That said, Karen smoked cigarettes, she drank too much alcohol, she ate the greasiest food from the scummiest dive restaurants and bars. Most everyone in her family was already dead from heart disease. She had a lot of risk factors going on, and she did absolutely nothing to improve her odds of living a long, healthy life.
As many others have said here (and said well), every surgery carries some risk. Whether to have SRS or not is really a quality of life issue that every trans person must discern for themselves. This much I know to be true, about SRS or any surgery: a healthy body, a healthy lifestyle, and a healthy attitude all go a very long way towards assuring an ideal outcome.
If SRS is something that you simply cannot live without (and it is most assuredly a choice that must not be taken lightly), then you are much better served putting your time, energy and resources into controlling those things that are within your control: your physical and mental health and well being. Worrying about what ifs and what fors and things that are out of your control is a waste of time and a waste of life.
Trust your heart. Listen to your intuition. It is there to guide you, and it will never steer your wrong.
I hope that something in my ramblings helps.
Peace,
Miharu