Disclosed are compositions, methods and kits to control bleeding through the use of an internal occluder based on polymeric solutions, including use of reverse thermosensitive polymers in nephron-sparing surgeries, which produces a completely bloodless surgical field, allowing speedy resection. In certain embodiments, after a certain amount of time, the flow gradually resumes, with no apparent adverse consequences to the kidney. In certain embodiments, return of blood flow may be accelerated by cooling the kidney. The compositions, methods and kits for perfusive organ hemostasis can also be used to simplify or to enable other organ surgeries or interventional procedures, including liver surgery, prostate surgery, brain surgery, surgery of the uterus, spleen surgery and any surgery on any highly vascularized organs.
