| 摘要 |
A surgical instrument has an elongate support shaft, a tip assembly permanently attached to the shaft, a cutting jaw which opens in a backward facing direction and which is laterally offset from the longitudinal axis of the support shaft, and a rod extending coaxially with the elongate support shaft for applying closing and opening forces to the cutting jaw. The tip assembly comprises a stationary portion and a movable portion having respective tissue cutting edges which define the cutting jaw. The stationary portion of the tip assembly is permanently attached to the distal end of the support shaft, and the movable portion of the tip assembly is pivotally attached to a distal end of the stationary portion. The stationary portion of the tip assembly has a plurality of cutting edges which define an opening which extends axially adjacent the longitudinal axis of the support shaft. The movable portion has corresponding cutting edges which cooperate with the cutting edges of the stationary portion to define the cutting jaw. The cutting jaw has a fully open position in which the movable element extends outwardly from the longitudinal axis and toward a proximal end of the elongate shaft at an angle of approximately 60 DEG . The cutting jaw has a fully closed position in which the cutting element is disposed within the opening in the stationary portion of the tip assembly. The tip assembly has an overall height dimension, when the cutting element is in the fully closed position, which is substantially equal to a corresponding cross-sectional dimension of the elongate support shaft.
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