The biggest complication is if they cut or damage the vagus nerve. Second is that The Toupet fundoplication or 270-degree wrap is equally effective in controlling GERD but tends to fall apart with time due to lack of strong serosal adhesions between the two edges of the wrapped gastric fundus and your GERD will return. Gas and sever bloating is also common and has effected my whole life. There is a facebook group called Nissen Fundoplication Take Down, that have several story's of people that have had complication that they don't tell you about. I have a NF 360 wrap that has not slipped but I'm so bloated that I there is almost no room for food, I can hardly eat any thing. I'm not absorbing vitamins and now I have SIBO. I will be having my NF taken down in Jan. This surgery was the worst decision that I have ever made. Also to top thing off, they never tested me for low acid in my stomach. Low acid in your stomach can cause the same symptoms as GERD. Heart burn and acid reflux!!!! Make sure that they test you and that you really need the surgery in the first place. I wish that I would have know about this 4.5 years ago. I really wish you the best.