Gaara blocked 5 susanoo swords with normal desert sand which is inferior to the sand in his gourd when not even looking and he was tired so imagine the power of the sand in his gourd, he was also able to protect everyone from the meteors which destroyed madara and his susanoo. His defense is not weak and can surely handle tsunade's hits with no problems.
He cracked sasuke's susanoo's ribs and hit him in the face which was suppose to be a definite kill but kishi just used plot to save sasuke.
What destructive feats do those susanoo swords have? What hype do they have? Absolutely none. I hate when Gaara fans bring that point up to say that their favourite character is invincible when in reality, that susanoo sword is nothing and Tsunade was able to tank a few herself so your point?
No Sasuke was fine and Raikage wasn't even close to killing him.
Anyway I might make a fan fiction of this battle, it actually interests me.
Tsunade: Charges at Gaara.
Gaara: Throws sand hail at Tsunade.
Tsunade: Dodges the sand hail.
Gaara: Creates a huge wall of sand to prevent Tsunade from coming through.
Tsunade: Uses heavenly kick of pain to send the sand flying.
Gaara: Reuses that same sand from behind and traps Tsunade into a mini sand coffin.
Tsunade: Activates Byakogu or whatever it is called and uses her strength to push the sand away from her body. She takes some miniscule damage but is healed right away.
Gaara: Continues to try and overwhelm Tsunade but it is of no use and Tsunade successfully closes the distance completely.
Tsunade: Uses a full force punch to breach Gaara but while her punch made it through, she got stuck.
Gaara: Tries to sand coffin Tsunade's hand while she is stuck but Tsunade effortlessly breaks out and creates a gaping hole in the defence which Gaara instantly regenerates. He decides to fly in the air.
Tsunade: Summons Katsuyu to reach the same height as Gaara.
Gaara: Throws a sand tsunami at Tsunade.
Tsunade: Uses the acid of her slug to melt a gaping portion of the tsunami and then jumps up in the air and attacks Gaara who is in mid air.
Gaara: Braces his shield of sand as tightly as possible.
Tsunade: Manages to breach once again and this time is able to touch Gaara and send electric signals to his nerves but falls short in actually landing a hit against him.
Gaara: Tries sand coffin again but Tsunade manages to escape yet again.
Tsunade: Decides to use katsuyu to melt Gaara's sand defence to weaken it allowing Tsunade to rush in and take advantage of the weakening of the defence to finally land a critical hit.
Gaara: He turns out to be a sand clone which traps Tsunade.
Tsunade: Katsuyu melts the sand clone and Tsunade sees that Gaara is now on the ground and immediately goes on the offensive.
Gaara: Now he uses all that sand in the environment to create a massive sand pyramid thereby sealing away Katsuyu for good. He shows signs of exhaustion and his sand attacks are slowing down.
Tsunade: Notices Gaara's weakening strength and realizes that his defence will become too weak to defend against her own attacks and to conserve her own chakra, decides to cancel her regeneration jutsu and instead rely on speed and dodging tactics to fight.
Gaara: Tries to get away but since he can't control his nervous system, can't do much but hope for the best. Manages to land a lethal hit against Tsunade.
Tsunade: She realizes it was a bad mistake in trying to conserve her chakra so she decides to activate her jutsu again but by then it is too late and Gaara uses a massive amount of sand to bury Tsunade and crush her into pieces.
Gaara: Victorious but panting vigorously and has lost control over his nervous system.