My surgeon at Mayo talked me off the cliff regarding open vs laparoscopic or robotic surgery prior to having 2 tumors removed from a kidney. Simply said, the more complexities being faced, the higher the possibility of bleeding that could lead to a transfusion, or could cause other types of leakage in confined affected spaces (urine leaks, bile leaks, etc.) Plainly stated, it would take time to withdraw all laparoscopic or robotic equipment in the case of a leak, wherein he'd've had to open me up anyway, and by then we'd be talking transfusion. Risk of bleeding would be abated by him being able to immediately "grab" any bleed and stop it.