It was reported to rwmic by the manufacturer that "on april 12, 2022 richard wolf (b)(4) was informed about the following: at the time of a resection of a bladder polyp, the distal tip of the cutting electrode melted leaving round parti-cles similar to small metal balls in the bladder.The surgeon then attempted to remove these small balls, which resulted in a delay of 30 minutes.The treatment could be completed.This case was reported by the customer to (b)(6).".
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Follow-up report #1 is to provide fda with the results of the device investigation.It was reported by the manufacturer, rw gmbh that: the customer was contacted several times to get more information.However, no response has been received until today.The present 8622131 cutting electrode bipo 24fr 12/30° from batch 1473127 has been inspected.The electrode has a fused-on shaft at the distal end and also the remains of a melted wire at the distal end.The wire loop is no longer present at the time of analysis.Thermal effects are clearly visible.A definite cause cannot be given due to the lack of information on the hf generator used and the power parameters set.Design-related or manufacturing-related errors cannot be detected.The following possible application errors could have led to the present case: contact with other metallic objects: touching metallic objects can cause short-circuit currents and thus high temperatures, which could possibly also lead to melting of the distal wire loop.Use of incorrect parameters on the hf generator: excessive power settings can lead to short-circuits and/or increased current concentrations at the wire loop and thus to strong wear or even melting of the distal electrode.The 8622131 cutting electrode bipo 24fr 12/30° has been in the programme since 13.11.2008.From the batch 1473127 a total of (b)(6) pieces were booked into stock on 07.06.2021.The following quantities were shipped to our subsidiary rw (b)(4) from batch 1473127: (b)(6) 2021 -> (b)(6) pieces.(b)(6) 2021 -> (b)(6) pieces.(b)(6) 2021 -> (b)(6) pieces.The period 01.01.2019 to 12.04.2022 was subjected to a closer examination of the complaints database.During this period (b)(6) pieces of 8622131 cutting electrode bipo 24fr 12/30° were sold and no similiar com-plaints are known for this model.So far, no further cutting electrodes from the affected lot 1473127 have been returned to richard wolf gmbh.The associated ifu ga-d342 / en / 2021-03 v16.0 / pk20-0295 / contains the following instructions for hf application: use caution!: the products have only limited strength! exerting excessive force will cause damage, impair the function, and therefore endanger the patient.Immediately before and after each use, check the products for damage, loose parts, and completeness.Make sure that no missing parts remain in the patient.Do not use the products if they are damaged or incomplete or have loose parts.Hf application warning!: excessive hf voltage! exceeding the maximum recurring peak voltage of the hf instrument in combination with hf surgical devices and/or the incorrect selection of the operating mode can destroy the insulation and lead to leakage currents.Thermal tissue damage to the patient, user, and others is possible.Warning!: incorrect selection of the hf output power! injuries to the patient, as well as damage to the product are possible.The power setting must adjusted in ac-ordance with the operator's experience / training with reference to the applicable indication.Warning!: risk of hf arcing! too small a distance between high-frequency current-carrying parts and other conductive parts, as well as sig-nificant heat generation, can lead to unintentional damage to the tissue and to damage of the ceramic on the sheath and on the endoscope.Activate high-frequency current-carrying parts of hf instruments only in the ex-tended state (fig.23).In the event of hf arcing, replace the electrode immediately, check the endoscope for damage, and, if necessary, send in for repair to prevent consequential damage.Warning!: risk of injury in the sphincter / cervical region! if the power settings exceed the value recommended by the hf device manufacturer, there is an increased risk of thermal damage and abrasion as well as a risk of breakage of the electrode bracket (wire).Greater irritation of the obturator nerve is also possible in this case, and the resulting twitching may promote unintentional perforation.Set power settings according to the value specified by the hf device manufacturer.The depth effect (necrosis) is about 0.5 to 2 mm, depending on the power / mode of the electrode.Therefore, be especially careful near the sphincter / cervix and use the lowest possible hf power.A dark brown coloration or carbonization of the tissue indicates excessive power.Caution!: excessive power setting may lead to significantly higher electrode wear.To determine the optimum power set-ting, we recommend starting with a low power setting.Checks: warning! injuries due to damaged or incomplete products! injuries to the patient, user, and others are possible.Do not use the products if they are damaged and incomplete or have loose parts.Run through the checks before and after each use.In the risk assessment b2-3 reusable resecting electrodes rev.04, production-related, handling and design hazards with regard to a functional impairment as well as risks from a product that cannot be used were consid-ered with the corresponding extent of damage and the assumed probability of occurrence and evaluated with an acceptable risk.Hazard (3): 5.8.4 thermal energy.Function/component (1): 3.4 distal ending.Causes (3): 5.4 handling-related -> 5.4.8 wear-increasing application.Harms (1): extension of the procedure.Since no new risks have arisen from the investigation of the current complaint case, the risk assessment re-mains valid in view of the facts described.As a conclusion, the correct selection of power settings and an appropriate handling during hf application are an essential point in the use of electrodes.But, as no further information are available, a final assessment cannot be made.Richard wolf gmbh considers this matter closed.However, in the event rw gmbh receives any additional information a follow-up report will be submitted to fda.Richard wolf medical instruments corporation (rwmic) is submitting the report on behalf of rw gmbh.
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