A needle unit includes an outer cannula and an inner wire passing through a passageway thereof. The outer cannula is straight or curved, and the outer cannula has a piercing end and an open end connected to the passageway. The piercing end has a dull tip. An opening is disposed around the dull tip of the piercing end or at the top of the cannula. The inner wire has a threading part at an end thereof near an opening of the outer cannula, it allows the suture thread passing through the threading part and it is movable inwardly or outwardly via the opening. Therefore, the needle unit can be advantageous to tie the desired vessels or parenchyma of a liver in hepatic resection with less restriction.
