RNY same danger as Open Heart?
Open heart surgery (bypass) is far more serious and complicated. They have to crack the chest open to get to the heart and that entails them cracking the ribs open. After that the medical team prepares the patient to go on the heart lung bypass machine. This causes the heart and lungs to stop beating and breathing and a machine takes over the function of a beating heart and lungs. A vein is also sometime during this process located in the leg to create the bypass. After all the vein attaching the team will have to take the patient off of the bypass machine. From what I understand this is a tense time for the team before the heart and lungs start back up again.
WLS surgery is not without its risks. There can be complications from infection, blood clots, stoma closing, anesthesia for the obese patient, deep wound infection, just to name a few.
I have given you the layman's explaination of your question because I am sure that I left something out or did not explain something really well. You really need to talk to your doctor to get the medical explaination to your question.