Implanted date: device was not implanted.Explanted date: device was not explanted.The actual device has been returned for evaluation.Visual inspection of the actual catheter and guidewire did not find any anomaly including a kink over the entire length.Magnifying inspection of the actual catheter did not find any anomaly including an elongation or a crush.X-ray fluoroscopic inspection of the lumen of actual catheter found that the coil had been jumbled and obstructed inside the strain relief.No anomaly such as a jumble or an obstruction of the coil was found in other sections.Magnifying inspection of the actual guidewire found that the outer layer had been peeled off at approximately 720mm - 770mm from the distal end and had been flared at approx.1000mm from the distal end.Each peeling and flaring of the outer layer went straight from the hand side to the distal side.No anomaly such as peeling or flaring of the outer layer was found in other sections.After priming the inside of actual catheter and the surface of actual guidewire, an attempt was made to insert the guidewire into the catheter.It got stuck inside the hub of catheter.The strain relief of actual catheter was removed and visual inspection of it was performed.It was found that the catheter had been buckled in the vicinity of adhering section between the hub and the catheter, and a black substance had been clogged inside the buckled section.The black substance found in investigation result 6 was collected and investigated by ft-ir.It was found that it was consistent with the spectrum of outer layer on the surface of guidewire attached to the product.Ft-ir (fourier transform infrared spectroscopy): an analysis method that confirms the molecular structure of an object by analyzing the spectrum obtained by irradiating the object to be measured with infrared light.Since the wavelength of infrared rays absorbed is almost unique to each substance, qualitative analysis can be performed by comparing with the infrared standard absorption spectrum.From inspection of the actual sample, it was inferred that the peeled guidewire outer layer was clogged inside the buckled section.Adhesion of outer layer of the actual guidewire was confirmed under a magnifier at the section where the outer layer was not peeled off.No anomaly such as floating or a gap was found between the wire and the outer layer.The outer layer was intentionally scraped to check the internal condition.The outer and inner diameters of actual catheter (normal section) were measured and confirmed to meet the specifications.The outer diameter of actual guidewire was measured and confirmed to meet the specifications.Review of the manufacturing record and the shipping inspection record of the involved product code/lot# combination confirmed that there were not any anomalies in them.A search of the complaint file found no other similar report with the involved product code/lot# combination from other facilities.Simulation test was conducted using a factory retained progreat, the guidewire was vigorously removed from the catheter with insufficient priming.As a result, resistance was occurred.The guidewire was continuously removed under resistance.It was found that buckling occurred in the vicinity of adhering section between the hub and the catheter inside the strain relief.In addition, the surface of guidewire was abraded at the buckled section of catheter, causing peeling, and flaring of the outer layer of the surface of guidewire.Each peeling and flaring went straight from the hand side to the distal side.These conditions were very similar to the actual sample.Based on the investigation result, as a possible cause of this complaint, the event was likely to have occurred by the following mechanism.When removing the guidewire attached to the actual sample, priming was insufficient.Therefore, the frictional resistance between the inner surface of catheter and the outer surface of guidewire became high, and resistance was occurred.The guidewire was continuously removed under resistance.Due to this, the catheter was buckled in the vicinity of adhering section between the hub and the catheter inside the strain relief.The surface of guidewire was abraded at the buckled section of catheter, causing peeling, and flaring of the outer layer, and the peeled outer layer adhered to the inside of buckled section of the catheter.When the guidewire was reinserted into the catheter, it was caught in the buckled section of catheter or the clog of the outer layer of guidewire inside the buckled section.Therefore, it could not be inserted.Ifu states: "prime the catheter and guide wire sufficiently.Manipulation of an insufficiently primed catheter may cause wrinkling, separation of the catheter, and/or abrasion of the hydrophilic coating on the guide wire." and "if any resistance is felt while removing the guide wire, do not remove the guide wire by force.The resistance may indicate insufficient lubricity of the guide wire.Flush the catheter again with heparinized saline solution.If any resistance is felt while removing the guidewire, do not remove the guide wire by force.Drawing back the guide wire against resistance may cause the catheter kink.Carefully remove the guide wire together with the catheter." (b)(4).
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