Sheathes for surgical instruments, and related devices and methods

A sheath assembly for a medical instrument shaft, the sheath assembly comprising:

• a sheath sleeve configured to receive the medical instrument shaft;
• and
• a sheath retention mechanism comprising:
• a sheath attachment portion configured to attach the sheath retention mechanism to the sheath sleeve, and
• a locking collar extending from the sheath attachment portion, the locking collar comprising one or more resilient members,
• wherein the one or more resilient members are configured to deflect radially outward from a first, undeflected position to a second, deflected position in response to a radially inward directed force applied to a portion of the locking collar,
• wherein, in the first, undeflected position, the one or more resilient members are a first distance from a central axis of the sheath sleeve,
• wherein in the second, deflected position, the one or more resilient members are a second distance from the central axis of the sheath sleeve, the second distance being greater than the first distance, and
• wherein, in an attached state of the sheath retention mechanism to the sheath sleeve, the sheath retention mechanism and the sheath sleeve permit insertion of the medical instrument shaft through the sheath retention mechanism and the sheath sleeve.