Suit self-seals after damage

In his personal quarters aboard the Exactor, Vader examined the damage the Zabrak lightsaber had done to his left forearm. After assuring himself that the pressure suit had self-sealed above the burn, he had peeled off the long glove and used a fine-point laser cutter to remove flaps of armorweave fabric that had been fused to the alloy beneath. The Jedi's lightsaber had sliced through the shielding that bulked the glove and had melted some of the artificial ligaments that allowed the hand to pronate. Permanent repairs would have to wait until he returned to Coruscant. In the meantime he would have to entrust his arm to the care of one of the Star Destroyer's med droids.

Dark Lord: The Rise of Darth Vader, Part II, Page 82