A medical ninjutsu where one anticipates the spot the enemy will attack and pre-emptively applies medical treatment to it, reducing damage to a minimum. The user concentrates chakra to that area and begins the cell recreation process even before the targeted area becomes damaged. Using opponent's facial expression and movements, the technique's speed and power, the user analyses everything in an instant and accurately deduces where the attack will land. Even more than accurately predicting the attack or instantly gauging the situation, a great resilience is necessary, so one might say this technique is exclusive to Kabuto.
Kabuto claims that this technique is the reason that Orochimaru values him so highly: he can keep using test subjects for much longer than is normally feasible. The technique will continue to heal damage until the user runs out of chakra, leaving the possibility that the damage will not be completely mended when the technique ends.
In the anime, after Tsunade returned to Konohagakure and gave her prognosis on Rock Lee's condition — thinking back to how she saw Kabuto withstand Naruto's Rasengan, Tsunade used Kabuto's technique as an inspiration to expand on the life-threatening operation and improve Lee's chances of survival from 50% to 58%.