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The following article was received for review on the (b)(6) 2014: 'outcome of metallic stents for malignant ureteral obstruction; from the devising of urologic surgery.Duke university medical center, durham, north carolina.The journal of urology, vol 188, 851-855, september 2012.The article indicates the study interval to be september 2010 through july 2011.The pts involved in the study underwent placement of the cook manufactured metallic resonance stent for malignant ureteral obstruction.Upon review of the article it was noted that subcapsular hematomas developed in three pts after resonance stent placement.Please note that two cases had previously being logged in 2011 by a physician involved in the study.Cook (b)(4) had not previously received the article related to the study.This report is being sent in relation to the third pt involved.The pts presented with persistent flank pain, mild anemia (mean decrease in hemoglobin 1.8 gm) and absence of leukocytosis or fever.A rep ct demonstrated a subcapsular hematoma of the right kidney, with the proximal stent coil in the expected position in the renal pelvis.Mean time to presentation for this complication was 14 days after stent placement (range 3 to 20).Each of these cases was managed conservatively and none required transfusion or intervention.All 3 cases improved on serial imaging.Physician of study believes that hematoma formation may be related to excessive length of the inner cannula relative to the outer sheath in the supplied introducer system.A radiopaque marker is located at the distal end of this outer sheath.Thus, when the radiopaque marker of this introducer system is advanced to the renal pelvis, the physician believes the inner cannula projects further into the renal tissue.To avoid this complication the user now routinely cuts off the distal tip of the inner cannula to the same level as the open-ended sheath before advancing the introducer system over a guidewire.
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The following article was received for review on the january 19, 2014: 'outcomes of metallic stents for malignant ureteral obstruction.From the division of urologic surgery, duke university medical center, durham, north carolina.The journal of urology, vol 188, 851-855, september 2012.The article indicates the study interval to be september 2010 through july 2011.The pt's involved in the study underwent placement of the cook manufactured metallic resonance stent for malignant ureteral obstruction.Upon review of the article it was noted that subcapsular hematomas developed in three pts after resonance stent placement.Please note that two cases had previously being logged in 2011 by a physician involved in the study.Cook (b)(4) had not previously received the article related to the study.This report is being sent in relation to the third pt involved.The patients presented with persistent flank pain, mild anemia (mean decrease in hemoglobin 1.8 gm) and absence of leukocytosis or fever.A rep ct demonstrated a subcapsular hematoma of the right kidney, with the proximal stent coil in the expected position in the renal pelvis.Mean time to presentation for this complication was 14 days after stent placement (range 3 to 20).Each of these cases was managed conservatively and none required transfusion or intervention.All 3 cases improved on serial imaging.The pts did not have diagnosed coagulopathies and only 1 was receiving systemic anticoagulation perioperatively (325 mg aspirin daily).A sensor ptfe-nitinol guidewire was used to place 2 of these stents, and an amplatz super stiff guidewire was used in 1 pt.Neither guidewire perforation nor contrast extravasation was noted at stent placement.Physician of study believes that hematoma formation may be related to excessive length of the inner cannula relative to the outer sheath in the supplied introducer system.A radiopaque marker is located at the distal end of this outer sheath.Thus, when the radiopaque marker of this introducer system is advanced to the renal pelvis, the physician believes the inner cannula projects further into the renal tissue.To avoid this complication the user now routinely cuts off the distal tip of the inner cannula to the same level as the open-ended sheath before advancing the introducer system over a guidewire.As per above, the physician of study believes that hematoma formation may be related to excessive length of the inner cannula relative to the outer sheath in the supplied introducer system.However, the length of the inner cannula is not considered a device malfunction.This case did not require transfusion or intervention.All cases improved on serial imaging.Engineering analysis of the reported event was provided as follows: there is an approximate 5cm extension of the catheter over the sheath length.The function of the length is to ensure that any dilation of a stricture has enough exposed catheter to allow back and forth advancement while advancing the sheath thorough the stricture.With respect to the issue of penetrating the kidney the introducer is placed over a wireguide, therefore it should not be exposed as a protruding tip in isolation once the introducer is in position the wireguide and inner catheter are to be removed and so there should not be any concern as mentioned at this point.Furthermore, the catheter tip has a shaft bonded to a flexible tip.The shaft being stiffer than the tip gives good pushability and the flexible tip is nice and soft.It would be very difficult to perforate a kidney with a catheter with this type tip.It is said in the complaint that the user now cuts off the tip - this would not improve the situation for the user as the tip is now a non flexible end.It is possible this is the source of their issue.A definitive cause for the customer's complaint was unable to be determined because the actual use condition could not be duplicated in the lab setting.Due to a variety of clinical conditions such as pt anatomy or progression of disease state.Cook ireland could not reproduce the actual conditions of device usage.The device involved in the complaint was not available to be returned for eval.With the info provided, a document based investigation was carried out.The rpn for this complaint was not provided but is most likely: rms xxxxxxr (as per article stent length is between 20 and 28cm), therefore rms-060026-r has been used in this complaint for logging purposes.The lot number of the resonance metal stent was not provided; therefore, it was not possible to check if any of the affected lot remained in stock.Prior to distribution, resonance stent devices are subjected to visual inspection and functional checks to ensure device integrity.As the lot number of the device involved in this complaint was not provided, it was not possible to conduct a review of the device mfg records for this device.The rms-060026-r devices are used for temporary stenting of the ureter in adult pts with extrinsic urethral obstruction.These devices are intended for one-time use.As per instruction for use: users are cautioned as follows: "individual variations of interaction between stents and the urinary system are unpredictable.Use of this device should be based upon consideration of risk-benefit factors as they apply to your pt, informed consent should be obtained to maximize pt compliance with f/u procedures".The complaint was confirmed based on the customer testimony of an adverse event occuring as a result of usage of the rms device.The length of the inner cannula is not considered a device malfunction.The case was managed conservatively and did not require transfusion or intervention.All cases improved on serial imaging.Customer qa will continue to monitor complaints of this nature for potential emerging trends.
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