Approximately 30mins into a routine bypass case for MVR it was noted that a white ring was floating on the surface of the blood in a Sorin 6F Dual oxygenator reservoir (picture1). The case was managed on a Liva Nova S5 pump, incorporating a roller pump with pre and post membrane pressure measurement, and CDI inline monitoring. Prior to going onto bypass aprotinin had been added to the separate cardiotomy section of the reservoir only for it to pass through to the venous section. The perfusionist believed this was due to the plunger not being completely closed. No impact to the patient occurred because of this.
On discovery of the ring (visible against the red blood) it was derived it had originated from the plunger (picture2) resulting in a lack of seal for the cardiotomy isolator. The ring remained on the surface of the blood (reservoir level over 1000ml) for the majority of the case and it was decided no intervention was required. Cases at this hospital do not utilise cardiotomy separation routinely.
Towards the end of the case when the heart was filled for de-airing and the level in the reservoir allowed to drop (remaining above the level sensor at 250ml), the ring seemed to disappear. No bypass parameters changed.
After termination of bypass and draining of the reservoir to the cell saver the ring was observed in the reservoir outlet (picture3). The patient and bypass management were unaffected by this incident.
None
Liva Nova Inspire 6F Dual Oxygenator
The details of the incident were forwarded to Liva Nova and the report below returned.
Investigation Summary: LivaNova received a report stating that the inner white o-ring of Inspire HVR dual lot 2202250135 got detached during surgery.
Analysis of complaints database revealed no other similar cases notified for batch concerned from the market. Explanatory picture as evidence of the defect was provided, showing that involved component (reasonably one of the two o-rings assembled on the sequestration wall system) was floating inside the unit filled with blood.
Based on the above findings, and taking into account the manufacturing process of affected device, it cannot be ruled out that the most likely root cause of reported failure was assigned to a loose connection of the o-ring in assembly line, leading the part to be disconnected since pushed by in-coming blood flow rate.
Consequently, the personnel will be involved in a dedicated training meeting aware of customer complaint. Liva Nova maintains and documents periodic customer events monitoring process in order to evaluate actions for products improvement.
Root Causes: The root cause of the event was identified in loose connection of the o-ring in assembly line, leading the part to be disconnected since pushed by in-coming blood flow rate.
Corrective Actions: According to CPMIRSOP000087, the personnel will be involved in a dedicated training meeting awaring of customer complaint. LivaNova maintains and documents periodic customer events monitoring process in order to evaluate actions for products improvement.
Appropriate agency informed.