hemodialysis is one of the most important treatment options in end - stage renal failure patients . there are synthetic and autogenous intervention methods to implement hemodialysis ; the best of these methods is autogenous arteriovenous fistulas . we examined the fistula cases that we constituted as using the  diamond - shaped anastomosis  technique . the diamond - shape method has been compared with other methods via geometrical analysis and it has been reported that this method permits more blood flow as compared with other methods of anastomosis . the objective of this study was to compare the success rates of the diamond - anastomosis technique to those of other arteriovenous fistula methods reported in the literature . we retrospectively examined 67 randomly selected cases ( 33 radiocephalic and 34 brachiocephalic ) , on whom the  diamond - shaped anastomosis  technique was performed . no radiological examination was used in patient selection before the application of this technique and the patients were selected in a totally randomized fashion . twenty - three of the patients were females with a mean age of 49.2 ( between 38 and 71 years ) , and 44 were males with a mean age of 55.1 ( between 31 and 78 years ) . the most distal region of the non - dominant arm was used for the first procedure . after the evaluation of the palmar arcus by performing an allen test before the anastomosis , radiocephalic anastomosis was performed if no fistulas were formed previously . the artery and vein on which the anastomosis was planned to be performed on were prepared and dissected on the nondominant arm . after determining the site where the anastomosis would be performed , the vein is distally ligated , cut and transposed to the site of anastomosis . proximal and distal arterial and proximal venular clamps were placed and then a diamond - shaped arteriotomy was done as described by sen et al . then , the vein to be used for anastomosis was freed and longitudinal venotomy was done . the length ( between a  b or a  d ) of this incision performed on the vein wall is important as it defines the angle of the anastomosis and the cross - sectional area . the distance between the b and a points in the vein must be equal to that between points 2 and 1 in the arteriotomy . similarly , the distance between the d and a points in the vein must be equal to that between points 4 and 1 in the arteriotomy . thereby , the long legs of the diamond arteriotomy are equal to the length of the longitudinal venotomy created . the sum of the distance of each of the b and d points at the vein to point c is equal to the perimeter of the vein . the half - perimeter of the vein ( between points b and c and points c and d ) should be equal to half ( between 3 and 2 and between 3 and 4 ) of the shorter leg of the diamond arteriotomy . although these requisites might seem complex , they can be easily adapted to surgery when geometrical rules are well known . following arteriotomy , the first procedure is to place single sutures with prolene 7 - 0 to 3 corners ( from 3 to c ; from 4 to d ; and from 1 to a ) ( fig . the objective in placing these sutures at the beginning is to ensure that the corners are seated in harmony with each other . starting from 3 and c , the suture is continued until arriving at 4 d , then it is affixed to the suture placed in 4d . after this , with the suture placed from 4d , the suture is continued until point a1 and it is affixed to the suture at point a1 . following this , finally , a new suture is placed between point b and point 2 , which is then continued to point c3 to conclude the procedure . therefore , sutures that do not follow each other were used with 4 different sutures between a1 and d4 , between d4 and c3 , between c3 and b2 , and between b2 and a1 . as each suture starts at exactly the right location , additional sutures to eliminate diameter mismatches turbulence is reduced in this method as no abrupt difference of diameter occurs between the artery and vein . the artery and vein on which the anastomosis was planned to be performed on were prepared and dissected on the nondominant arm . after determining the site where the anastomosis would be performed , the vein is distally ligated , cut and transposed to the site of anastomosis . proximal and distal arterial and proximal venular clamps were placed and then a diamond - shaped arteriotomy was done as described by sen et al . then , the vein to be used for anastomosis was freed and longitudinal venotomy was done . the length ( between a  b or a  d ) of this incision performed on the vein wall is important as it defines the angle of the anastomosis and the cross - sectional area . the distance between the b and a points in the vein must be equal to that between points 2 and 1 in the arteriotomy . similarly , the distance between the d and a points in the vein must be equal to that between points 4 and 1 in the arteriotomy . thereby , the long legs of the diamond arteriotomy are equal to the length of the longitudinal venotomy created . the sum of the distance of each of the b and d points at the vein to point c is equal to the perimeter of the vein . the half - perimeter of the vein ( between points b and c and points c and d ) should be equal to half ( between 3 and 2 and between 3 and 4 ) of the shorter leg of the diamond arteriotomy . although these requisites might seem complex , they can be easily adapted to surgery when geometrical rules are well known . following arteriotomy , the first procedure is to place single sutures with prolene 7 - 0 to 3 corners ( from 3 to c ; from 4 to d ; and from 1 to a ) ( fig . the objective in placing these sutures at the beginning is to ensure that the corners are seated in harmony with each other . starting from 3 and c , the suture is continued until arriving at 4 d , then it is affixed to the suture placed in 4d . after this , with the suture placed from 4d , the suture is continued until point a1 and it is affixed to the suture at point a1 . following this , finally , a new suture is placed between point b and point 2 , which is then continued to point c3 to conclude the procedure . therefore , sutures that do not follow each other were used with 4 different sutures between a1 and d4 , between d4 and c3 , between c3 and b2 , and between b2 and a1 . as each suture starts at exactly the right location , additional sutures to eliminate diameter mismatches turbulence is reduced in this method as no abrupt difference of diameter occurs between the artery and vein . in 1 case ( radiocephalic anastomosis ) we failed to find any thrill at all after surgery . the patients were observed without any changes in the dialysis protocols during the postoprative period . they were allowed to have hemodialysis from their operated arms on the 34 weeks of their surgery . patency in the arteriovenous fistula was observed in 60 out of 67 patients at 180 days after surgery . thrombosis was seen in 1 case and 1 patent had hematoma that was drained after diagnosis . enoxaparin was adminisrated to the patient with calcific radial artery for 3 days postoperatively ( 4000 anti - xa iu ) . the methods that fulfill these criteria are autogenous methods of intervention . with their high complication rates and ephemeral nature , synthetic methods are less favored . complication rates at the end of the first year are reported to be between 33% and 99% in shunt operations performed via synthetic grafts . autogenous arteriovenous fistulas are methods that have low infection rates , low costs , and lower complication rates , and are easily applicable . although autogenous fistulas have advantages , dysfunction rates at the early period ( in the first 1-month period ) reach to as high as 29% . this rate is reported to be 79% to 94% in the long term [ 813 ] . in the standard end - to - side slit technique that we applied in the periods before and after this study , the most frequently used anastomosis methods used while creating fistulas since the beginning have been side - to - side or end - to - side anastomoses . in performing these anastomoses , arteriotomy and venotomy are generally applied in a slit form . in this type of anastomoses , the rates of remaining patent of anastomoses created in the proximity of the upper extremities are found to be higher than those made in the distal upper extremities . in anastomoses made at the distal upper extremities , ( brescia - cimino ; snuff - box ) patency rates in the first 6 postoperative months are reported as 66% and 70% , respectively . in our study the causes of thromboses that evolve at the early stage include the surgical technique used , vasospasm , arterial calcification , unpropitious artery and vein diameters ( below 1,52 mm ) , high vein pressure , and external pressure . the problems that can emerge while applying the surgical technique include irregularity in the alignment of vascular walls during anastomosis , iatrogenic injury to the intima , accidental suturing from the rear wall , diameter mismatch between the artery and the vein in question , tissue penetration in between the sutures while placing the sutures , and a stretched anastomosis . apart from these factors , the drop in the blood that flows through the shunt in the early stage is another significant reason for dysfunction . when hypotension develops , arteriotomy lips can come next to each other , which may result in a further drop in the flow and cut off fistula flow , in cases in which slit arteriotomy is used . in diamond - shaped anastomosis , arteriotomy lips can not come exactly next to each other and thus dysfunction is prevented . in end - to - side anastomoses , a sudden change in vessel diameter can result in turbulence , which may cause thrombosis . in addition , as vasospasms are reduced in end - to - side anastomoses , flow drop or cessation associated with vasospasm might be prevented in diamond - shaped anastomoses as well [ 1820 ] . in addition , the incisions made and the suturing technique are also important in thrombosis formation . further , because 4 separate sutures are placed , no circular effect on the anastomosis takes places and , as the sutures are made under easy - to - view conditions , accidental suturing from the rear wall is prevented . additionally , postoperative hematomas are thus prevented and dysfunction may also be avoided . the bifurcation region is straighter in the diamond technique as compared with the slit technique , which reduces turbulent flow . the wider anastomosis surface in the diamond - shaped anastomosis technique compared to other techniques also increases the flow passing through the fistula . performed mathematical modeling and calculation of the diamond - shaped anastomosis , finding that the diamond - shaped anastomosis technique increases the surface area of anastomosis , which reduces turbulence . the same study reports that the angle that forms between the artery and the vain is taken as an angle- and a calculation was made based on that . according to this calculation , with the its flow - related and hemodynamic advantages , diamond - shaped anastomosis is an effective method in reducing fistula dysfunction .
summarybackgroundobtaining vascular access suitable for long - term use in hemodialysis patients is of utmost importance . in these patients , 
 autogenous methods are generally used for access . 
 there are various techniques for obtaining autogenous access in hemodialysis patients.material/methodsour objective was to evaluate the outcomes of the  diamond - shaped anastomosis  technique used as a surgical technique during the creation of arteriovenous fistulas in patients with chronic renal failure . 
 we randomly selected and retrospectively examined 67 patients on whom the  diamond - shaped anastomosis 
 technique had been performed.resultswe found an 89% patency rate in the 67 randomly selected patients on whom we applied this technique in the early stage ( first 6 months).conclusionsmaintaining fistula patency in the early postoperative period is important in fistula functioning . 
 the diamond - shaped anastomosis is a simple technique with proven efficiency . 
 this method can be applied in all situations and contributes to postoperative early stage latency .