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Attention: officer (b)(6).Date: august 17, 2018 subject: response to fda request for the initial report.Fda follow up letter dated: 04/26/2018.Manufacturer reference number: (b)(4).Product description: carto® 3 system.This is a response to the fda¿s letter dated april 26, 2018, regarding a report of an adverse event with the following event description: it was reported that a patient underwent a pulmonary vein isolation (pvi) ablation procedure for atrial fibrillation with a carto 3 system and suffered a cardiac tamponade requiring pericardiocentesis.During ablation of the left pulmonary vein, the contact force of the first thermocool smarttouch sf bi-directional nav catheter displayed as "hi".The physician stopped ablating and attempted tozero the catheter, which led to "n/a" and "error 106" being displayed.The cable was changed and the issue persisted.The catheter was changed to the second thermocool smarttouch sf bi-directional nav catheter and the physician indicated that the contact force and the vector of the 2nd catheter felt different than expected.The physician zeroed the catheter multiple times and continued the procedure.When the left pvi was complete, the patient became hypotensive.Physician assessed the echocardiogram and proceeded to perform the right pvi.Upon completion, the physician re-assessed the echocardiogram and performed a pericardiocentesis.Blood pressure recovered and the cavotricuspid isthmus (cti) ablation was performed.There is no information regarding extended hospitalization.Patient outcome has improved.There were no factors cited that may have contributed to the adverse event.It was noted that the adverse event may have occurred during ablation phase.Physician indicated that he may have applied additional force due to a discrepancy between the carto merge image and the physician's estimation based on his spatial understanding of the situation.It was noted that the positional relationship between ct and catheter was different from what the physician thought due to the lack of accuracy of cartomerge.Physician's opinion regarding the cause of the adverse event is that it was related to a bwi product malfunction and procedure.After reviewing the event information provided by the fda, we matched this event to our database by fda manufacturer report number, event date, event description, hospital information and device (model and catalog number).We have verified that this event is in the biosense webster, inc.(bwi) complaint database with manufacturer reference number: (b)(4).Biosense webster reported this complaint as an mdr under initial report number for the carto 3 system.Because there were two other devices reported as part of the complaint, biosense webster also filed reports for each of those devices: report 9673241-2017-00158 for a thermocool® smart touch® sf bi-directional navigation catheter and report 9673241-2017-00155 for another thermocool® smart touch® sf bi-directional navigation catheter.The report identified in this additional information request is for the carto 3 system, so this response will focus primarily on that report, however we will describe the results of the investigation on the catheter that was returned for inspection.If you require additional information about the reports related to the catheters used in this procedure, biosense webster can provide that additional information.Please provide the results for any investigation, evaluation, and/or failure analysis, including underlying cause identification, relevant to the reported event.Please include: (1) an explanation for the reason for this occurrence based on your follow-up with the reporting facility or individual (2) a complete description of investigation and analysis methodology(ies) used, (3) an identification of the specific failure mode(s) and/or mechanism(s) and the associated device component(s) involved, and (4) any conclusions reached based on the investigation and analysis results.Response: investigation related to the carto 3 system complaint: the physician reported a concern that the cartomerge module in the carto 3 system presented an image that was different than the physician¿s spatial recognition of the anatomy, which may have led to increased force being applied, resulting in cardiac tamponade.The cartomerge module for the carto 3 system allows the user to integrate pre-acquired mri and ct images into the electro-anatomical maps generated by the carto 3 system using a navigational catheter, such as the thermocool smarttouch sf bi-directional nav catheters used in this case.Biosense webster offered to inspect the carto 3 system to determine whether service was necessary, but the customer did not accept this offer because the carto 3 system reportedly worked properly on the next case.Therefore, biosense webster was unable to confirm the complaint about the cartomerge module.The history of customer complaints associated with this specific carto 3 system (serial # (b)(4)) was reviewed.There were no additional complaints involving the cartomerge software.The device history record for the carto 3 system unit was reviewed and no anomalies were noted in the manufacturing or servicing of this equipment.Investigation related to the thermocool smarttouch sf bi-directional navigation catheters.The physician used a thermocool® smart touch® sf bi-directional navigation catheter and noted a ¿high¿ contact force during ablation.The carto 3 system displays a ¿hi¿ message when excessive force is applied with the catheter.When the physician noted this high contact force, an attempt at ¿re-zeroing¿ the catheter or recalibrating the force sensing resulted in the error 106 being displayed.A second thermocool® smart touch® sf bi-directional navigation catheter was used to complete the ablation and the physician noted that the force and vector ¿felt different¿ from what was expected.The physician zeroed the catheter multiple times and continued with ablation and it was then that the patient was noted to be hypotensive and an echocardiogram was performed.Only one of the two catheters used in the procedure were returned for inspection.When the functionality of catheter sensor was tested on the carto 3 system, the eeprom data demonstrated that the catheter was properly calibrated during manufacturing and the catheter was recognized by the carto 3 system.As reported by the customer, the error 106 was displayed, indicating an issue with the force sensor.Dissection of the catheter revealed an internal failure of the sensor.The root cause of the internal sensor damage could not be determined during the product analysis.The device history record (dhr) was reviewed for both catheters and no anomalies were found.The dhr review verifies that the catheters were manufactured in accordance with documented specifications and procedures.No manufacturing issues related to these catheters were found.The 2017 hrs/ehra/ecas expert consensus statement on catheter and surgical ablation of atrial fibrillation states that the incidence of pericardial complications range from 0.74% to 2.24%.Higher incidence of cardiac tamponade during af ablation compared with routine cardiac electrophysiology procedures can be attributed to a number of important procedural differences, including extensive intracardiac catheter manipulation and ablation, the common need for two or more transseptal punctures, and the need for systemic anticoagulation.Based on the report, the first catheter initially performed properly by displaying a ¿hi¿ contact force message during the ablation.The subsequent display of error 106 and the damage to the catheter¿s force sensor confirmed by the inspection suggest the possibility that the sensor was damaged during the procedure.The thermocool smarttouch sf ifu states that careful catheter manipulation must be performed in order to avoid cardiac damage, perforation or tamponade.What actions has your firm taken to address this problem? response: complaint trends are monitored monthly, and no significant trends have been identified at this time related to the accuracy of the cartomerge module for the carto 3 system.Please provide the results of risk management activities completed by your firm which address the reported device problem.Indicate the frequency and severity of the hazard, cause(s), and the applicable control(s) implemented to mitigate the hazard.Response: biosense webster¿s risk management process has assessed both the risk of this adverse patient experience and the risks related to the cartomerge module.As the carto 3 system is capital equipment, the sales of the consumable product used in conjunction with the system are used to calculate an occurrence rate for this issue.The cartomerge module is an optional module within the carto 3 system, therefore the occurrence rate is likely lower, because not all carto 3 cases use the cartomerge module.The occurrence rates for the issues reported in this complaint are as follows (based on utilization of the carto 3 system): cardiac tamponade with cartomerge issue occurrence rate is (b)(4).Issues with the cartomerge module feature are listed as sl2.The ifu warns the physician of inherent inadequacies with the cartomerge module and instructs the end user to rely on ¿common clinical practice for real-time verification of catheter locations throughout the procedure (such as inspection/monitoring of ic signals and annotations, fluoroscopy or other imaging modalities, etc.), as failure to do so might result in incorrect placement of the catheter.¿ please provide a complete list of medical device reports (mdrs) that you have determined are related to this same problem/issue.Please identify how many complaints (i.E.From all sources, including but not limited to field service records, repair history records, etc.) that your firm has received in the past 2 years that are related to this same reported device problem.There has been 1 mdr (which is this complaint) reported to the fda in the past two years related to a cartomerge issue with reported cardiac tamponade.The following manufacturer initial report number was submitted.It should be noted that the reported cartomerge issue is not a reportable event in and of itself.The issue is highly detectable.The uploading of images is done prior to their use in the procedure, and the feature is used for added guidance only.It is not required to perform the procedure.If there is a suspected issue with the cartomerge feature, the accuracy/quality of the images can easily be compared to the original images on hand, at which point the use of the cartomerge feature can be discontinued if necessary.Please provide the total number of devices manufactured, distributed and, if available, used per year over the last three years for the medical device identified in the medical device report.Please indicate the proportions distributed in the us and outside the us.Response: there were (b)(4) manufactured in the last three years distributed over the last three years: row labels: 2015, 2016, 2017, 2018 grand total.Ous: (b)(4).Us: (b)(4).Grand total: (b)(4).Please provide where in the ifu is this issue addressed regarding a discrepancy in the carto reading and physicians estimation.Response: on page 14 of the carto 3 ifu, safety for modules and optional features, in the section for the cartomerge® plus module the ifu states ¿color interpolation of electrical information between two relatively distant images (ultrasound and carto® 3 system) can lead to user misinterpretation of data when registering the two images.This might lead to an incorrect ablation target.¿ on page 10 the end user is to ¿use common clinical practice for real-time verification of catheter locations throughout the procedure (such as inspection/monitoring of ic signals and annotations, fluoroscopy or other imaging modalities, etc.).Failure to do so might result in incorrect placement of the catheter.¿ on page 95 there is a warning ¿proper registration is dependent on the correct placement of landmark pairs in corresponding locations on the surface image and map.Failure to place landmark pairs in the correct corresponding locations will provide invalid registration results.¿ on page 96, there is a note ¿always verify that the correct map has been matched to the correct surface image.Incorrect matching of maps to surface images will result in incorrect registration, and misleading information regarding patient data.Always verify registration before matching maps to surface images.¿ on page 97 there is a note ¿projection of color on a surface image is an approximation based on acquired point data and the quality of registration.Always refer to the acquired point data before making clinical decisions.¿ also, on page 97, under verifying registration ¿verification of effective registration is essential, to be able to refer to the surface image during a carto® 3 study.The quality of registration can be verified by maneuvering the catheter on the chamber walls or vessel structures and checking for consistency between the real-time position of the catheter icon and the currently used registered anatomical structures.In addition, examining the intracardiac signals can help determine the location of the chamber wall relative to the catheter tip.Statistical data and calculations regarding the closeness of fit are viewed in the landmark and surface tabs of the match statistics panel.A visual representation of the fit can also be displayed via the registration match view option.Careful review of the information provided via these options will help determine how closely the surface image and carto® 3 map match after registration.¿ it also cautions ¿use of the match statistics and registration match view does not replace verification of registration according to your common clinical practice, such as fluoroscopy or inspection of ic signals.Final determination of effective registration is mandatory, and should be performed on the target area of interest.¿ manufacturer's ref.No: (b)(4).Attachment: [carto 3 ifu.Pdf].
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