adequate vascular access is of critical importance for patients who require extracorporeal renal replacement therapy . although an arteriovenous fistula ( avf ) is the golden standard access for hemodialysis , temporary dialysis catheters are frequently required . the national kidney foundation kidney disease outcomes quality initiative ( k / doqi ) suggests that catheter access is usually achieved through cannulation of 1 of the 3 easily accessible central veins , namely the femoral , internal jugular , or subclavian veins . the internal jugular veins are preferable locations for insertion . however , the femoral vein is often selected as well , depending on the patient 's condition . several complications are associated with the insertion of these catheters , including infection , bleeding , deep venous thrombosis , and injuries to arteries . thrombosis and infections are the common complications during catheter insertion as well as in the already inserted catheters . an avf is a rare but severe complication following catheterization for patients who require hemodialysis . we describe a case of an iatrogenic avf after cannulation of the femoral vein for temporary hd leading to leg swelling 6 months after removal of a hemodialysis catheter . a 42-year - old asian man with a history of diabetic ketoacidosis and acute renal failure ( arf ) was first admitted to a satellite hospital 6 months ago . a temporary double - lumen hd catheter was smoothly inserted into the right femoral vein . blood samples were collected through the catheter to confirm its venous origin , and hd was performed through the catheter . bleeding from the catheter insertion site was observed 5 days after admission , when he walked to the restroom . at that time , the platelet count was normal and international normalized ratio ( inr ) was 2.45 . six days later , the serum creatinine level become normal and urine volume was much more than 1500  ml / day after the comprehensive treatment . the catheter was removed to stop the continuous bleeding ; as a result , the patient was able to walk without bleeding and subsequently discharged . the patients received insulin therapy and stayed in good condition in the follow - up . six months after the catheter removal , he was admitted to our institution because of right lower limb swelling and calf pain . on physical examination , the temperature was 36.9c and blood pressure was 140/80  mmhg , the jugular venous pressure was normal , and the pulse was regular at 75  beats / min . body mass index ( bmi , weight / height ) was 21.5 . a bruit was heard on auscultation and a thrill was felt at the inguinal area . serum levels of creatinine , blood urea nitrogen ( bun ) , and hemoglobin were 98  mol / l , 5.6  mmol / l , and 10.8  g / dl , respectively . his serum potassium and sodium were 4.9 and 138  meq / l , respectively . an avf was detected by color doppler ultrasound between the right superficial femoral artery ( sfa ) and the right femoral vein and subsequently it was confirmed by 3-dimensional reconstruction with ct and angiography ( figures 1 and 2 ) . three - dimensional ct revealing an arteriovenous fistula between the right superficial femoral artery and the right femoral vein ( arrow ) . angiography revealing the arteriovenous communication ( between the superficial femoral artery and superficial femoral vein ) . initial treatment involved dilation of the stenotic lesion immediately beneath the bifurcation of the right common iliac artery using a balloon and stent insertion . during operation , the surgeon found a 3-mm diameter fistula between the right femoral vein and the right sfa . the right femoral vein and sfa were separated carefully . then , vascular repairing was carried out with running nonabsorbable sutures . a 42-year - old asian man with a history of diabetic ketoacidosis and acute renal failure ( arf ) was first admitted to a satellite hospital 6 months ago . a temporary double - lumen hd catheter was smoothly inserted into the right femoral vein . blood samples were collected through the catheter to confirm its venous origin , and hd was performed through the catheter . bleeding from the catheter insertion site was observed 5 days after admission , when he walked to the restroom . at that time , the platelet count was normal and international normalized ratio ( inr ) was 2.45 . six days later , the serum creatinine level become normal and urine volume was much more than 1500  ml / day after the comprehensive treatment . the catheter was removed to stop the continuous bleeding ; as a result , the patient was able to walk without bleeding and subsequently discharged . the patients received insulin therapy and stayed in good condition in the follow - up . six months after the catheter removal , he was admitted to our institution because of right lower limb swelling and calf pain . on physical examination , the temperature was 36.9c and blood pressure was 140/80  mmhg , the jugular venous pressure was normal , and the pulse was regular at 75  beats / min . body mass index ( bmi , weight / height ) was 21.5 . a bruit was heard on auscultation and a thrill was felt at the inguinal area . serum levels of creatinine , blood urea nitrogen ( bun ) , and hemoglobin were 98  mol / l , 5.6  mmol / l , and 10.8  g / dl , respectively . his serum potassium and sodium were 4.9 and 138  meq / l , respectively . an avf was detected by color doppler ultrasound between the right superficial femoral artery ( sfa ) and the right femoral vein and subsequently it was confirmed by 3-dimensional reconstruction with ct and angiography ( figures 1 and 2 ) . three - dimensional ct revealing an arteriovenous fistula between the right superficial femoral artery and the right femoral vein ( arrow ) . angiography revealing the arteriovenous communication ( between the superficial femoral artery and superficial femoral vein ) . initial treatment involved dilation of the stenotic lesion immediately beneath the bifurcation of the right common iliac artery using a balloon and stent insertion . during operation , the surgeon found a 3-mm diameter fistula between the right femoral vein and the right sfa . it is reported that traumatic avf , a complication of femoral vein catheter insertion for hd , is an exceptional disease . however , when it occurs , it is often caused by damage to an artery while inserting a catheter into a vein . chronic limb edema , false aneurysms degeneration , and high output cardiac failure due to fistula are common complications . to prevent this , several studies have demonstrated that real - time ultrasound guidance is superior to traditional landmark insertion techniques for the insertion of dialysis catheters because real - time ultrasound guidance is of particular value in increasing first - pass  rates and reducing the risk of hematoma formation and other complications related to catheter insertion . moreover , the use of a fine - gauge needle to locate the vein before introduction of the guide wire using the seldinger needle is suggested as well . avf as a complication of dual - lumen hd catheter insertion has been described in the medical literature . kuramochi et al described a case of right superficial femoral avf with a symptom of arterial bleeding . chiba et al reported a case of an avf associated with calf pain 2 months after the removal of the catheter . according to the literature , the most common initial symptoms were swelling , hemorrhage , limb pain , hematoma , thromboembolism , and cardiac failure . limb swelling along with calf pain as the initial symptom was rare in any of the cases . but in this case , the patient was initial with a symptom of limb swelling and calf pain . chiba et al reported a case of femoral avf observed 2 months after catheter removal . in the present case , it seems that femoral avf might be observed later than cervical avf , probably because of inaccessibility to the groin area . several explanations were possible for the formation of femoral avf : ( 1 ) the femoral head provides posterior bony support , and it might be difficult to achieve hemostasis for the lack of bony support during compression following catheter removal . ( 2 ) avf once closed by a hematoma might be reopened by movement or anticoagulation with heparin during hd . ( 3 ) presumably , femoral avf formation is caused by relatively larger caliber of the catheter and occult arterial puncture . in the present case , the anticoagulation with heparin during hd might be a reason for femoral avf formation . the risks factors that increase the likelihood of developing avfs included distal groin punctures , arterial hypertension , antiplatelet therapy , and peri - procedural anti - coagulation in this case , the low puncture might increase the likelihood of developing avfs . moreover , there was no real - time ultrasound - guided that had been used for catheter insertion . the traditional landmark insertion techniques are commonly performed using anatomic landmarks to guide vessel cannulation . these traditional techniques can not direct visualization of the target vein during catheter placement and are associated with an increased complication rate . so , it is recommended that real - time ultrasound is performed to direct guidance of the needle insertion to avoid repeated blind punctures . femoral venous catheterization is frequently selected to achieve temporary access to circulation in patients requiring acute hemodialysis . thus , it is important for nephrologists and nursing staff to be aware of this potential complication and to perform thorough clinical and medical examinations at the insertion and removal of temporary hd catheters . it is recommended that real - time ultrasound guidance should be used for catheters insertion to avoid inadvertent arterial puncture .
abstractdouble - lumen catheters have been used widely to obtain temporary access in patients who are in need of acute hemodialysis ( hd ) because of acute renal failure . 
 several complications are associated with the insertion of these catheters , including bleeding , infection , injuries to arteries , and deep venous thrombosis . 
 an arteriovenous fistula ( avf ) is a rare but significant complication following catheterization for temporary hd . 
 herein , we present a case of avf associated with leg swelling 6 months after the removal ofa double - lumen hd catheter.we describe a special case of a 42-year - old man who experienced acute renal failure secondary to diabetic ketoacidosis ( dka ) . 
 a 12-fr dialysis catheter was inserted in the right femoral vein . 
 six months after catheter removal , the patient was admittedfor pain and swelling in the right leg . 
 color doppler ultrasound and three - dimensional computed tomography ( ct ) revealed an avf between the right femoral vein and the right femoral superficial artery . 
 the fistula was repaired successfully by vascular surgeons.this case highlights that an avf is a rare but significant complication after catheterization for temporary hd . 
 the nephrologist should be wary of the potential of this complication and perform clinical and medical examinations at the insertion and removal of temporary hd catheters .