MAUDE Adverse Event Report: SIEMENS MEDICAL SOLUTIONS USA, INC. ACUSON Z6MS ULTRASOUND TRANSDUCER; ULTRASOUND DEVICE, PRODUCT CODE: ITX

Model Number Z6MS

Device Problems Collapse (1099); Mechanical Problem (1384)

Patient Problem Ulceration (2116)

Event Date 12/18/2018

Event Type  malfunction  

Manufacturer Narrative

This mdr will be supplemented if additional information is received.Reference complaint # (b)(4).

Event Description

It was reported that an "in patient" underwent a trans-esophageal echocardiography (toe) procedure.During the procedure, the transducer folded over on itself inside the patient's esophagus.The transducer was inserted 10-15 cm without an issue.It was then noted that the image was inverted.Because there was no trouble when inserting the transducer it was further advanced into the stomach where normal manipulation was attempted.It was confirmed via x-ray that the transducer had folded over.The med team took the patient to icu and used a pediatric endoscope under sedation to examine the transducer and remove it - no surgery required.During the endoscope procedure a sub mucosal ulceration was observed, however, no perforation was observed.There was no injury reported.The patient was discharged to the ward two days later.No additional information was provided.

Manufacturer Narrative

Investigation results: the transducer was returned to siemens engineering, and an analysis of the transducer found a guide tube monocoil detachment.The root cause for this is an oversized flex circuit, related to the cable assembly design.Loading of the oversized flex circuit stretched the monocoil, which it was not designed for, and over time the bond failed.The flex circuit is considerably bigger than the space available within the monocoil, including the guide springs.When the cable to flex area (approximately 50mm from the articulation section) is bent acutely (more than 90 degrees), the cable to flex bundle can get caught on the monocoil.When the bundle catches the monocoil, it can apply tensile stress to the monocoil (a spring inside the guide tube).When the part is bent in the cable to flex area, the monocoil is stretched.When the monocoil stretches, this increases the tensile force on the monocoil to monocoil mount.This in turn applies stress to the joint, and it fails in shear.This use case of bending this section is not typical or expected.However, depending on how the user manipulates it either in handling, usage, storage, cleaning, packaging, or repairing, it could be bent this way, and the user would feel the force and break.Discussions with the third-party repair house indicated it was likely broken prior to use.The break should have been obvious, and the insertion should have been extremely difficult to achieve.It is not clear how the part would have broken while inside the patient, because the part is not in tension while the cable to flex area is not bent to a high angle.There was no information in the device history record which indicates any non-conformance at the time of manufacturing process.Based on the manufacturing date of the transducer, this is an older design that has since been changed to prevent occurrence of the issue.A plastic wrap was removed, which is the cause of the cable bundle catching on the monocoil, and the cable assembly design has been changed to reduce flex.The acuson sc2000 instructions for use state: warning: prior to each use, inspect the endocavity or intraoperative transducer for signs of mechanical damage such as cracks, cuts, tears, perforations, or protrusions.Do not use the transducer if the transducer appears damaged in any way.A damaged transducer could cut the patient or user and compromise the electrical safety of the transducer, causing possible patient or user injury.Contact your local siemens representative.Reference (b)(4).

• Brand Name: ACUSON Z6MS ULTRASOUND TRANSDUCER
• Type of Device: ULTRASOUND DEVICE, PRODUCT CODE: ITX
• Manufacturer (Section D): SIEMENS MEDICAL SOLUTIONS USA, INC.; 685 east middlefield road; mountain view CA 94043 4050
• MDR Report Key: 8237710
• MDR Text Key: 134493688
• Report Number: 3009498591-2019-00001
• Device Sequence Number: 1
• Product Code: ITX
• Combination Product (y/n): N
• PMA/PMN Number: K142628
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: company representative,foreig
• Remedial Action: Modification/Adjustment
• Type of Report: Initial,Followup
• Report Date: 01/10/2019

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 01/10/2019
• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Model Number: Z6MS
• Device Catalogue Number: 10436113
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 01/11/2019
• Date Manufacturer Received: 04/24/2019
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1