Description of Event or Problem · 1
THIS FACILITY'S REPORT IS A REBUTTAL RESPONSE TO THE MANUFACTURER'S MANDATORY REPORT #9612638-2012-00001, WHICH WAS FILED BY VARIAN MEDICAL SYSTEMS ON (B)(6) 2012. VARIAN REPORTED THE CONCLUSION: USER ERROR CAUSED EVENT. THE FACILITY OBJECTS TO THE MANUFACTURER'S USE OF CONCLUSION CODE OF THEIR REPORT. USER ERROR HAD NOTHING TO DO WITH THE MALFUNCTION OF THE DEVICE. THE UNDERLYING CAUSE FOR THE ADVERSE EVENT WAS A MFG DEFECT FOR REASONS AS FOLLOWS. THIS REPORT RELATES TO CONSTRICTION INSIDE A VARIAN BRACHYTHERAPY DEVICE KNOWN AS "TANDEM" RESULTING IN MISPLACEMENT OF THE HDR SOURCE WHILE TREATING A PT. THE TANDEM IS PART OF A FLETCHER SUIT DEVICE (FSD) USED FOR BRACHYTHERAPY TREATMENT OF CERVICAL AND ENDOMETRIAL CANCER. THE PRESCRIPTION FOR THIS PT WAS 400 CGY PER FRACTION TO POINT A FOR FOUR FRACTIONS. THE FRACTIONS WERE DELIVERED ON (B)(6). IN THE FIRST F/U VISIT ON (B)(6), THE PHYSICIAN DISCOVERED UNUSUAL SKIN REACTION REPORTED AS THE EXCORIATION ON THE LIBIA MAJORA BILATERALLY SYMMETRICALLY AND AN ERYTHEMATOUS REACTION ON THE THIGHS BILATERALLY, LATERALLY, AND CRANIALLY AGREEABLE TO RADIATION REACTIONS. SEARCHING FOR POSSIBLE REASONS FOR ANY CAUSE OF THIS SKIN REACTION WE REVIEWED PLANNING AND DOSIMETRY, CHECKED DWELL POSITIONS ACCURACY, SOURCE POSITION ACCURACY, ETC. UNTIL WEDNESDAY (B)(6), WHEN HE DECIDED TO LOOK AT ALL THE GUIDE DEVICES TO SEE IF WE FIND ANY PROBLEM. OF THE THREE SETS OF FSD'S WE FOUND THAT TWO TANDEMS WERE BLOCKED WHEN A GUIDE WIRE GETS INSERTED AT APPROXIMATELY 9 CM FROM THE TIP OF THE TANDEM. THE BLOCKAGE WAS AT THE NECK WHERE IT NARROWS. SINCE THE CATHETER IS CLOSED END, NEITHER THE BRACHYVISION SYSTEM -TREATMENT COMPUTER GIVING ERROR- NOR THE STAFF COULD REALIZE THAT THE SOURCE IS NOT POSITIONED CORRECTLY TO START DWELLING FROM THE END OF THE TANDEM WHERE IT IS ALWAYS INTENDED TO BE THE START POSITION. HAVING CUT ONE OF THE TANDEMS A FEW MM ABOVE THE POINT OF CONSTRICTION, WE DETERMINED THAT THIS ERROR IS MFG DEFECT RELATED SINCE WE CAN CLEARLY SEE THAT THERE IS CORROSION INSIDE OF THE TANDEM LARGE ENOUGH TO BLOCK THE GUIDE WIRE. SHOWN IN THE FIGURES BELOW, A SET OF TANDEM AT DIFFERENT ANGLES ARE DISPLAYED, WHERE THE 15 DEGREE TANDEM WAS CUT AND IMAGE WAS ACQUIRED OF THE INSIDE OF THE TUBE SHOWING THE CORROSION. CONTRARY TO OUR FINDING, VARIAN HAS REPORTED THE ROOT CAUSE TO BE AN OBSTRUCTION IN THE LUMEN CONSISTENT WITH A DAMAGED TANDEM. THEY INDICATED IN THEIR REPORT TO FDA THAT THEIR ENGINEERING INVESTIGATION HAS POINTED OUT THAT THE DAMAGED AREA IS CONSISTENT WITH A FORCIBLE REMOVAL OF THE CERVICAL STOP WITH TWISTING FORCE, WITHOUT THE SET SCREW LOOSENED COMPLETELY. THE SPECIFIC EVIDENCE POINT OUT BY VARIAN REFERS TO THE SPIRAL SCORING MARK ALONG THE SMALLER DIAMETER OF THE TANDEM, AND THE PLANES THROUGH WHICH THE TANDEM WAS BENT. THEY CONCLUDE THAT IT IS NOT POSSIBLE TO DETERMINE WHETHER ANY FORCE WAS APPLIED IN AN ATTEMPT TO RESHAPE THE TANDEM, BUT THIS COULD HAVE FURTHER OBSTRUCTED THE LUMEN. WE HAVE HAD VARIAN RETURN THE APPLICATORS THEY EXAMINED. OUR INSPECTION OF THE APPLICATOR WHICH VARIAN CLAIMS WAS DAMAGED BY IMPROPER USE SHOWS THAT THE OBSTRUCTION DOES NOT COINCIDE WITH A SMALL CREASE IN THE DISTAL PORTION OF THE APPLICATOR. THE EVAL BY VARIAN DOES NOT EXPLAIN WHY THREE OTHER TANDEMS ARE ALSO OBSTRUCTED AT A POINT WHERE THE MOST NARROW DISTAL PORTION OF THE APPLICATOR IS WELDED TO THE INTRAUTERINE COMPONENT OF THE APPLICATOR. VARIAN REP IN THEIR COMMUNICATION TO UT INDICATE HOWEVER THAT: "THE OTHER TANDEM RETURNED SHOWED A WELD OCCLUSION AT AN UNEXPECTED LOCATION DUE TO MFG PROCESSES IN PLACE AT THE TIME THE TANDEM WAS RELEASED FOR SALE. THE ORIGINAL INSPECTION METHOD DEPLOYED THE SINGLE USE PTFE TRANSFER GUIDE TUBES, WHICH HAVE A SMALLER DIAMETER THAN THE NEWER WHITE REUSABLE TRANSFER GUIDE TUBES. AT THE TIME THE NEW WHITE RTGTS WERE RELEASED, THE IFU WAS UPDATED WITH INFO TO ALLOW CHECKING INSERTION DEPTH USING MARKS ON THE RTGT MATERIAL, TO ENABLE QUICKLY CHECKING WHETHER THE TGTS ARE FULLY INSERTED." IN SUMMARY, OUR INSPECTION OF THE 4 TANDEMS FOUND TO BE NARROWED AND NOT PERMITTING THE TREATMENT CATHETER TO BE POSITIONED AT THE TIP OF THE APPLICATOR SHOW THAT THE OBSTRUCTION OCCURRED AT THE WELD POINT JOINING THE INTRAVAGINAL AND INTRAUTERINE PARTS OF THE TANDEM. AS INDICATED ABOVE, IN AN E-MAIL TO DR. (B)(6), ONE OF THE VARIAN REPS ADMITS, "THE OTHER TANDEM RETURNED SHOWED A WELD OCCLUSION AT AN EXPOSED LOCATION DUE TO MFG PROCESSES." WE CONTEND THAT IT IS A MFG ERROR/DEFECT WHICH LED TO THE PT INCIDENT AND NOT A MISUSE OF THE APPLICATOR. OBVIOUSLY, AN IMPORTANT ISSUE IS THE REMOVAL OF THESE INSTRUMENTS FROM OTHER CLINICAL SITES.