Explaining that the harrowing 27-hour operation only had a 13 percent chance of success, doctors from UCSF Medical Center recalled Thursday the incredibly difficult procedure to separate the conjoined Splash Brothers at birth. We quickly discovered a bleeding internal vein shared between the two that didnt appear in our initial 3D imaging, causing us to almost lose Steph right away, said lead surgeon Robert Pacheco, adding that his 12-doctor team of pediatric surgeons and anesthesiologists worked in shifts to separate the then-newborn Splash Brothers, whose bodies were initially fused from the top of the abdomen to the pelvis. The most significant complication arose when we realized the two shared a liver and part of the digestive tract, so we had to proceed very cautiously, and fortunately managed to avoid hitting any arteries. Because of the unexpected blood loss early on, we were prepared to lose one or both Splash Brothers, but they fought through the procedure, and thankfully, the two of them made it. Pacheco added that some kidney damage suffered during the operation caused Stephs stunted growth, which remains the reason he is still much smaller than Klay. 