This report is being supplemented to provide additional information based on the legal manufacturer's final investigation.The device was returned and inspected.The clip was attached to the device when it arrived for investigation.The clip opened/closed when the slider was moved.When the slider was pulled completely and then pushed out, the clip opened again.Therefore, the clip could not be released.The control section was also checked.The limiter in the control section of the clipping device was broken off.The thickness of the limiter was checked and found to be within the specified value.The dimensions of the hook was measured and found to be within specifications.A review of the device history record found no deviations that could have caused or contributed to the reported issue.Olympus confirmed "deploy prematurely" is reproduced when the clip arm is opened and closed using a method not recommended/included in the instructions for use (performed on lot 24k - 2yk and reproduced at 24k).In addition, the dimensions of the available lots (24k to 2yk) were checked to see if the occurrence of this phenomenon was caused by the dimensions of the parts.The dimensions of the hooks and clip arm related to this phenomenon were within the standard values.However, in 24k, the clearance between the hook and claw varied toward a smaller value compared to other lots."premature development" is more likely to occur when clearances are smaller.The clearance plays a significant role to open and close the clip arm.Size of the clearance affects detachment of the clip arm and operability such as ¿ deploy prematurely¿.Detachment of the clip arm easily occurs when the clearance becomes larger.On the other hand, ¿deploy prematurely¿ easily occurs when the clearance becomes smaller.The clearance of the measured products fell within the standard values.However, it was confirmed that the size of clearance was close to the lower limit.When the clearance is small, the clip arm will be placed in a specific position against the hook.When the incorrect steps are followed, such as closing the clip arm in the tube sheath, or opening and closing the clip arm repeatedly by not grasping anything in the clip arm, causing the clip pipe to get stuck at the rear end.This possibly leads to "deploy prematurely".Based on the results of the investigation, an association between adverse events and the device could not be ruled out.It is likely the event occurred when the clip could not be reopened because the "deploy prematurely" occurred.It is also possible that the limiter was ruptured and could no longer be released.Based on the results of the present product confirmation and the results of the reproduction study to date, it is considered that the trigger effect was not obtained due to the following mechanism: 1.The slider was pulled for the clipping.2.Due to the following compounded factors, a force of pulling the slider was reduced before it reached to the clip.- resistance between the operation wire and the coil sheath increased due to the shape of the scope or excessive angle of the scope.- the amount of force required to close the clip increased due to the large amount of grasping object.- hard tissues were grasped.- the base of the arm was pressed against the tissue, making it difficult to close the clip.3.A force required to close the clip did not be reach to the clip.Therefore, the limiter located in the slider broke (heard the snapping sound) before the clip completely closes.4.Since the limiter made a snapping noise, the user pulled the slider as he/she was misunderstanding that the clipping was completed.5.Since the clip was not closed completely, it could not be released.(the clip arms were being opened.) as for "deploy prematurely" there were no problems in the investigation, and no abnormalities were found in the product.The event can be detected and prevented by following the instructions for use which state: "when the bending section of the endoscope is excessive angulation and/or the target tissue is firm, the pulling force acted on the control section may not convey to the clip adequately, making clipping unsuccessful.Operation of this instrument is based on the assumption that open surgery is possible as an emergency measure if the clip cannot be detached from the instrument or if any other unexpected circumstance takes place.In this case, refer to chapter 14, ¿emergency treatment¿.¿do not withdraw the instrument forcibly or change the angulation of the endoscope when the clip is grasping the tissue and is not released.Doing so may tear tissue inside the body cavity, resulting in patient injury, such as perforation, bleeding, or mucous membrane damage.Do not angulate the bending section of the endoscope or withdraw the instrument from the endoscope while the clip is grasping the tissue before being released.This could cause patient injury, such as perforation, bleeding, or mucous membrane damage.Do not try to forcibly withdraw the instrument from the endoscope if the clip cannot be detached from the instrument.Forcibly withdrawing the instrument could cause patient injury such as perforation, bleeding, or mucous membrane damage.Should the slightest irregularity and/or breakage of the parts be suspected, withdraw the instrument from the endoscope immediately according to the steps of ¿withdrawing the instrument from the endoscope¿ on page 10.Otherwise, perforation, bleeding, or mucous membrane damage may result.Do not force the clip against body cavity tissue.This could cause patient injury, such as perforation, bleeding, or mucous membrane damage.The clip may be deformed and therefore does not close properly.This could result in reduced performance.Keep the insertion portion of the instrument that extends from the biopsy valve and the insertion portion of the endoscope as straight as possible.Do not perform clipping with the insertion section being coiled.Otherwise, the force exerted on the control section may not convey to the clip adequately during clipping.This could result in reduced performance, making it impossible to close the clip or detach it from the coil sheath after clipping." olympus will continue to monitor field performance for this device.
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