a previously healthy 24-year - old , 67 kg , 164 cm woman , who had been diagnosed with olfactory groove meningioma , was scheduled to undergo craniotomy and tumor removal . anesthesia was induced , with an effect site concentration of 4 g / ml propofol and 2 ng / ml remifentanil , by target controlled infusion ( tci ) ; 50 mg rocuronium was given to facilitate tracheal intubation . while anesthesia was subsequently maintained by tci of 3 g / ml propofol and 2 ng / ml remifentanil , insertion of a central venous catheter through the right subclavian vein was attempted with two lumen indwelling catheter sets ( arrowguard blue , arrow international inc . the introducer needle was advanced at the infraclavicular site , 1 cm inferior to distal third of the clavicle towards the suprasternal notch , until free aspiration of blood was obtained . a j - shaped guide wire was passed through the venipuncture needle 20 cm beyond the needle tip . following removal of the needle slight resistance was felt , so the dilator was advanced by further application of force . the catheter was put into the skin after removal of the dilator , but it did not advance any further than 7 cm because of resistance ; second and third attempts were unsuccessful . the catheter was removed , but the guide wire could not be retracted , despite firm traction . following discussion with thoracic surgeon , it was decided that removal of the wire , along with the dilator , under fluoroscopic guidance should be attempted . under fluoroscopic guidance , tissue dilator was inserted to straighten the wire , and the wire was removed along with the dilator . because significant force was required to withdraw the wire , the inner filament of the wire broke ( fig . the gap between the divided ends was bridged by portion of coiled wire - cover that surrounded the inner filament ( fig . right internal jugular vein catheterization and surgery was performed uneventfully . a postoperative chest x - ray , taken in the surgical intensive care unit revealed no signs of hemothorax or pneumothorax . we present a case of kinking of a j - tipped guidewire during a subclavian vein cannulation attempt . a few cases of knotting , kinking , or entrapment of guidewires have been reported , and previous reports of this complication have performed a simple retraction without fluoroscopic guidance . in our case , the kinked guidewire was removed successfully with fluoroscopic guidance . to establish the etiology of kinking or knotting of guidewire , it is necessary to have an understanding of the structure and physical characteristics of the wires . the latter is designed as a helix to form a tunnel for the inner wire , and provides elastic properties . j - shaped curvature is achieved by flattening the round core to a thickness of 0.1 mm approximately 2.5 cm from the tip , which provides flexibility at the j - shaped tip . however , it becomes an area of structural weakness at the junction of the rounded and flattened segments , which can lead to potential breakage . according to testing of guidewires , the welded seams between the inner core and the outer covering at both ends are supposed to withstand tension of at least 17 n ( 1.73 kg force ) before they detach ; whereas in its middle section , the complete guide wire should withstand a stress of approximately 290 n ( 29.57 kg force ) . guidewires are flexible structures , which means they are likely to become kinked or knotted if any force is applied repeatedly or excessively . also , some maneuvers may damage the guide wire ; for example , as occurred in this report , excessive pushing tension was required to insert the dilator . furthermore , the dilator may have been forced to advance in a direction that diverged from the path of the wire , which led to kinking of the wire . a kinked or knotted guide wire should be removed carefully , as it can induce vessel injury , hemorrhage or embolization of the fractured wire . in some publications , the guide wire was removed by retraction without confirming the condition of the guide wire with a radiologic device . there is one other report in which a tissue dilator was used to tighten the knot and straighten the kinking wire , allowing it to be withdrawn along with the dilator such ; as was performed in our case . however , such blind maneuvers may result in fatal consequences such as tissue injury , major hemorrhage , or embolization of fractured wire fragments . in our case , to avoid these severe complications , careful retraction during removal of the guidewire was carried out under fluoroscopic guidance . the dilator was used to tighten and reduce the knot to its smallest diameter . because the circumference of the knot was the knotted wire could be removed with dilator ; i.e. the dilator and guide wire can be withdrawn as a unit . slight resistance was felt on attempting to remove the guidewire , and considerable force was required to remove the wire . as a consequence , the inner filament of the guidewire was broken . however , with the help of fluoroscopy , it was possible to prevent complete breakage of guidewire . the use of fluoroscopy can allow for early diagnosis of kinking or knotting of the guidewire , and realtime monitoring its structure during removal . for these reasons , when breakage or embolization of the guidewire occurs , a basket retrieval catheter or loopsnare catheter can be used for removal of the fragments under fluoroscopic guidance . surgical intervention is only considered if all of these methods fail to remove the wire . kinking , knotting and any further damage to the structure of the guidewires can only occur because of physical tension during their handling . therefore , we suggest that guidewires should not be advanced by application of force if any resistance is detected .
guidewire - associated complications that occur during the process of central venous catheterization include its kinking , looping , knotting and breakage . 
 the removal of a looped or knotted guidewire is problematic because it can cause vessel damage , major hemorrhage , or embolization of a fractured guidewire . 
 we report a case of guidewire kinking and its successful removal under fluoroscopic guidance .