Indian Journal of Vascular and Endovascular Surgery

: 2020  |  Volume : 7  |  Issue : 3  |  Page : 231--236

The utility of venous bifurcation for anastomosis with small-caliber veins in distal forearm radiocephalic arteriovenous fistula: Retrospective analysis of 52 fistula cases

Shobhit Sharma1, Sudipta Bera1, Ashwani Kumar2, Vivek Gupta3,  
1 Department of Plastic Surgery, Shri Ram Murti Smarak Institute of Medical Sciences, Bareilly, Uttar Pradesh, India
2 Dezire Clinic, New Delhi, India
3 Department of Plastic and Reconstructive Surgery, Sir Ganga Ram Hospital, New Delhi, India

Correspondence Address:
Sudipta Bera
Department of Plastic Surgery, Shri Ram Murti Smarak Institute of Medical Sciences, Bareilly, Uttar Pradesh


Context: Distal forearm radiocephalic (RC) arteriovenous fistula (AVF) is the gold standard for vascular access for hemodialysis. The use of venous bifurcation to facilitate anastomoses in small-caliber vessels is well known in microvascular surgery. Small-caliber cephalic vein (CV) is frequently encountered during AVF creation in the distal forearm. We present here the utility of this technique for the creation of distal RC AVF in small-caliber CVs. Objective: The objective was to assess the utility of venous bifurcation for distal forearm RC AVF creation in small-caliber CV. Methodology: Fifty-two cases with CV diameter <2.5 mm on color Doppler study and RC AVF created in the distal forearm between January 2015 and 2019 are reviewed for operative time, fistula maturation time, and patency rate. Patients were selected for fistula creation after clinical and color Doppler assessment. Cephalic venous bifurcation in the distal forearm was used for end-to-side anastomosis whenever feasible. Patients were followed up periodically for fistula maturation and patency. Results: Venous bifurcation was used in all 52 cases with a functional maturation rate 48/52 (92.30%). Functional primary patency rate was 46/52 (88.46%) at 6 months and 20/28 (71.42%) at 1 year. The mean fistula maturation time was 37.19 days. Conclusion: A cephalic venous bifurcation is almost always available for RC AVF in the distal forearm. Its utilization improves the success rate and feasibility of fistula creation in small-caliber veins without any delay.

How to cite this article:
Sharma S, Bera S, Kumar A, Gupta V. The utility of venous bifurcation for anastomosis with small-caliber veins in distal forearm radiocephalic arteriovenous fistula: Retrospective analysis of 52 fistula cases.Indian J Vasc Endovasc Surg 2020;7:231-236

How to cite this URL:
Sharma S, Bera S, Kumar A, Gupta V. The utility of venous bifurcation for anastomosis with small-caliber veins in distal forearm radiocephalic arteriovenous fistula: Retrospective analysis of 52 fistula cases. Indian J Vasc Endovasc Surg [serial online] 2020 [cited 2020 Dec 1 ];7:231-236
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Full Text


Native radiocephalic (RC) arteriovenous fistula (AVF) is the first choice for vascular access for hemodialysis (HD) as per the “FistulaFirst” recommendation of Kidney Disease Outcomes Quality Initiative of the National Kidney Foundation.[1],[2]

Distal RC AVF is considered as the first choice for AVF creation for easy vascular access, technical simplicity to construct, preservation of more proximal site for future access, and less complications such as postoperative edema or steal phenomenon.[3],[4]

Construction of RC AVF in primary attempt remains critical as it initiates dialysis early, reduces catheter dialysis period and related complications, and also reduces the expenditure.[5],[6] The selection of cases depends mainly on clinical examination and ultrasound examination.[3] Usually, cephalic vein (CV) of 2–2.5 mm diameter is considered for distal AVF creation,[7],[8] but there is no strict cutoff value. In clinical practice, vascular diameter >2.5 mm poses no problem for anastomoses for AVF creation, but CV diameter is frequently found below this range in the distal forearm during the first consultation. The establishment of fistula becomes challenging in distal small-caliber veins requiring more complex techniques.

The use of venous bifurcation to facilitate anastomosis is well known in microvascular surgery. However, the utility of this method, particularly for RC AVF, is not much discussed apart from few earlier studies.[7]

Venous bifurcation is almost always available in the distal forearm. The utilization of venous bifurcation for anastomosis thus may improve fistula creation in small-caliber veins, extending the feasibility of distal RC AVF at the initial consultations and increasing early AVF creation rate.

We present here the outcome of 52 RC AVF anastomoses in small-caliber CV for distal RC AVF and utility of this technique for small-caliber veins.


Inclusion criteria

All patients with CV diameter <2.5 mm on color Doppler study and underwent distal forearm RC-AVF formation between January 2015 and 2019 were reviewed retrospectively. Patient-related variables were collected from the hospital database and were assessed when an anastomosis was done utilizing the venous bifurcation point.

Selection criteria

Preoperative venous diameter, anatomy, and compliance were assessed clinically with a tourniquet applied at the proximal forearm. A color Doppler study of the forearm was done. Allen test was performed to check the patency of the palmar arch. The patient was selected for distal RC AVF when a distensible CV and a patent palmar arch were present. Nondominant forearm was preferred for the first-time fistula creation. In small-diameter vein (<2.5 mm), AVF was attempted in the distal forearm if a venous bifurcation point was available. If the branch point was not available clinically and by Doppler test, or in previous failed distal fistula, the opposite forearm was considered for distal fistula creation. Proximal veins were tried to be spared unless both vein and artery diameters were <1.5 mm without any detectable venous branch point. Only in these cases, a proximal forearm fistula was created at the first consultation without any attempt for distal fistula creation. Failed fistulas from this study where RC AVF was again created with a venous bifurcation in CV diameter <2.5 mm on the other limb were included as a separate procedure.

Operative procedure

All RC AVFs were constructed by the senior author under local anesthesia as a day-care procedure. The presence of major bifurcation point and incision site was located as per the clinical and color Doppler examination. CV was dissected out in the distal half of the forearm till the bifurcation point was noted and distance from the wrist crease was measured. Bifurcation point distal to the wrist crease was not used to prevent vascular kinking and angulation. Both the branches were divided distal to the bifurcation. The common wall was divided, and the margins freshened to convert it into a single opening [Figure 1] and [Figure 2]. Vein proximal to the bifurcation was dilated with a vascular dilator. Bifurcated limbs were kept longer for broader anastomosis in small-diameter veins, while they were kept to a minimum in larger veins [Figure 3]. The radial artery was exposed in distal one-third of the forearm, separated from its venae commitantes, and kept elevated in between two hemostatic clamps. An arteriotomy was made at the lateral wall of the elevated segment. Arteriotomy length was adjusted according to the venotomy maintaining the angulation of the fistula. The length of anastomoses was kept up to 10–12 mm. An end-to-side anastomosis was done using continuous suturing technique for posterior and anterior walls with 7-0 or 8-0 prolene. Hemostatic clamps were released and venous dilatation was noted [Figure 4]. Dilated segment was checked free from kinking and the notable larger venous branches nearby were ligated. Hemostasis was checked subsequently. The operative site was closed primarily in a single layer. The operated limb was kept warm and elevated. Patency of the anastomosis was checked clinically by palpating venous thrill or listening to audible bruit with a stethoscope on the table and half an hour postoperatively and rechecked again subsequently before discharge.{Figure 1}{Figure 2}{Figure 3}{Figure 4}

Follow-up for patency and maturation

Patients were followed up clinically for fistula patency and maturation on postoperative day 3, 7, and 14 and then subsequently as per the clinical findings. Progression of palpable thrill or audible bruit was noted. Clinical examination was confirmed with color Doppler study. When clinically palpable thrill and bruit were present in a minimum 5 cm dilated segment of the vein and had been evident on color Doppler study, the flow rate was checked with cannulation. When the flow rate was more than 250 ml/min, the patient was taken for dialysis and the AVF maturation time was noted.

Endpoint of follow-up

The patient was followed up till AVF had matured, and dialysis could commence through it then as and when required. If the AVF was blocked or failed to mature after a maximum of 4 months, the patients were considered for distal fistula on the other limb or proximal fistula on the same limb, as cost-effective measures in our institute. Distal fistulas which met the inclusion criteria were enlisted as a separate procedure. Otherwise, the patients were excluded from further follow-up in the present study. All the RC AVFs were followed up till a minimum period of 6 months.

Statistical analysis

All the data were tabulated and Statistical analysis was done with IBM SPSS Statistics software, version 20.0.1 (Armonk, New York, USA).

 Results and Analysis


In our study among the patients, 17were male and 35 were female. Forty RC AVFs were created in the left and nondominant hand, whereas 12 in the right hand. Forty-two cases were first-time fistulas and 10 were failed fistulas. Among the failed RC AVF, 8 were failure cases of the same study. The age of the patients ranged from 14 to 70 years.

The mean CV diameter was 1.8 mm with standard deviation (SD) 0.22 and standard error of the mean (SEM) 0.03. The minimum diameter was 1.5 mm. Arterial diameter ranged from 1.5 to 3.5 mm.

Venous bifurcation anatomy

Bifurcation point was identified in all cases with in 5 cm proximal to the wrist crease (mean distance: 4.65 cm, SD: 1.40, and SEM: 0.2). This enabled RC AVF creation in the distal half of forearm improving the feasibility of fistula creation with the venous bifurcation in all cases.

Operative outcome

The mean operative time was 33.24 min (SD: 6 and SEM: 0.32). There was no requirement to ligate any additional venous branch apart from the bifurcated branch in any case. Palpable trill at the anastomotic junction was present just after the operation in 40 cases (76.92%) and in all cases half an hour postoperatively. Audible bruit was present in all cases immediate postoperatively. The average progression of a thrill was noted approximately 1 cm/week. The anastomosis was successful in all 52 cases. No procedure was abandoned. The functional fistula maturation rate was 48/52. Failure due to thrombosis as evident by color Doppler study was noted in one case (1.92%). Three (5.76%) RC AVFs failed to mature even after 4-month follow-up. Fistula maturation time was 37.19 days (SD: 4.7 and SEM: 0.7).

Functional primary patency was 46/52 (88.46%) at 6 months and 20/28 (71.42%) at 1 year. Distal vascular compromise or hand edema was not noted or reported by any patient in the follow-up period.


RC AVF is the recommended first-choice access for dialysis as per the “fistula first” initiative to improve native fistula creation for HD by the National Kidney Foundation after its first use by Brescia et al. in 1966.[1],[9] Distal forearm RC AVF is considered for the first-time fistula creation for its easy vascular anatomy and location than more proximal site or utilization of the ulnar artery and basilic vein. Distal RC AVF provides a long segment of the vein for subsequent dialysis and preserves more proximal sites for future use. Although the high incidence of thrombosis, failure to mature or prolonged maturation time, and abandonment of fistula have been reported earlier,[4] still it is considered as the gold standard for its surgical simplicity.[3]

Improvement of feasibility and convenience to create a working distal RC AVF is critical as failure requires more complex procedures such as proximal radiocephalic fistula, brachiocephalic fistula, basilic vein transposition, or the use of vein graft. It increases the higher center referral rate, waiting period, duration of catheter dialysis-related complications, and subsequent cost.[5],[6]

Venous diameter is the most important predictive factor for fistula maturation. Sometimes, the lack of a larger caliber vein in the distal forearm creates difficulty for the selection of cases. Usually, venous diameter of more than 2.5 mm in preoperative color Doppler study permits for AVF creation, and the poor success rate has been noted in vein diameter <2 mm.[3],[7],[8],[10],[11] However, still, there is no strict lower cutoff value for the selection of cases. The feasibility of the procedure mostly relies on clinical judgments and color Doppler study.

Anastomosis in distal small-caliber vein proves to be challenging risking abandonment of the procedure. Although the use of venous branch point to facilitate microvascular anastomoses is well known and practiced, the utility of this technique for AVF is not widely discussed. Various surgical techniques such as “Carrel Patch,”[7],[12] “Venous Branch Patch”[13] or “Vein Mouth,”[14] and “Anastomotic Hood”[15] were described to improve vascular anastomosis in AVF. Jenning et al.[7] noted the broadening of anastomoses and improved the stenosis rate. Bharat et al.[15] found reduced juxta-anastomotic stenosis utilizing the bifurcation point in RC AVF.

We have practiced this method for small-caliber veins and tried to assess if it offers any benefit to extend the selection of cases for distal RC AVF creation.

We have noted that the bifurcation point was present in all 52 cases of small-caliber vein in either distal forearm. Among them, 40 were in nondominant and 12 were on dominant forearm. The mean distance of the bifurcation point was 4.65 cm (SD: 1.40 and SEM: 0.02) from the wrist crease. This enabled us to create RC AVF with the small-caliber vein in the distal forearm at the initial consultation in all 52 cases.

No procedure was delayed in small-caliber veins. The smallest diameter was 1.5 mm. We have noticed that the utilization of the bifurcation point converts a small-caliber venous opening into a larger venous rent, and the arteriotomy length could be adjusted accordingly to match the venotomy. Angulation and length of anastomoses thus could be adjusted for favorable hemodynamic effect.[16] In our study, the length of anastomoses was kept approximately 10 mm–12 mm. Juxta-anastomosis constriction was not encountered in any case [Figure 4]. Due to the increased feasibility to perform anastomosis, no case had to be abandoned. Improved technical comfort was noted, as the mean operative time was 33.24 min (SD: 6 and SE: 0.32), which is quicker than our earlier anastomotic time with small-caliber CV. On the table, venous dialatation and audible bruit were noted in all patients. Although palpable thrill was present in 40 patients just after anastomosis, it was present within half an hour in all the cases. We assume that this is due to vascular spasm which improved spontaneously. We have also noted that utilizing the branch point, there were no requirements to ligate any additional venous branch apart from bifurcated branch.

The primary failure rate of distal RC AVF varies from 9% to 40%.[4],[17] The maturation time in distal RC AVF has been mentioned earlier as 38 to120 days.[7],[11],[18],[19] Successful fistula maturation rate in veins <2 mm is even lower, ranging from 16% to 33% in earlier studies.[7],[10],[11],[18] Although very poor maturation rate and high rate of abandonment of RC AVF were described, we have noted better fistula maturation, particularly if the arterial flow was good. The functional maturation rate was 48/52 (92.30%). The mean maturation time was 37.19 days (SD: 4.7 and SEM: 0.7). Three RC AVFs did not mature to achieve a flow rate of 250 ml/min within 4 months. Forty-eight RC AVFs were useable for the dialysis. The primary patency at 6 months was 46/52. Twenty-eight RC AVF could be followed up for 1 year, of them 20 were patients and were used for the dialysis. Ten RC AVFs could be traced beyond this, of them 9 were patent at 2-year follow-up.

Our study is limited by the lack of secondary patency rate due to the lack of cost-effective radiological interventions at our center. It also requires more cases and longer-follow up to establish the utility in a more certain way.


Cephalic venous bifurcation is almost always available in the distal forearm at a favorable location allowing its feasibility to be used for anastomosis with the radial artery. Anastomosis remains at a superficial location allowing easy vessel handling and anastomosis.

The utilization of the bifurcation point broadens anastomoses desirably and improves technical comfort, fistula maturation, and patency rate in vein <2.5 mm.

It thus enables anastomosis with smaller diameter veins, extending the feasibility of distal RC AVF to smaller diameter veins (1.5–2.5 mm) with a similar outcome as observed in larger veins. It also enables fistula creation at the first consultation while preserves the proximal venous capital for future use without delaying the procedure. Hence, it could extend the selection of patient for primary native RC AVF creation at the distal forearm without delay to improve the venous diameter. This establishes early dialysis through RC AVF, preserves more proximal veins for future use, and avoids more complex procedures.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


1Lok CE. Fistula first initiative: Advantages and pitfalls. Clin J Am Soc Nephrol 2007;2:1043-53.
2III. NKF-K/DOQI clinical practice guidelines for vascular access: Update 2000. Am J Kidney Dis 2001;37:S137-81.
3Sidawy AN, Spergel LM, Besarab A, Allon M, Jennings WC, Padberg FT Jr.,et al. The Society for Vascular Surgery: Clinical practice guidelines for the surgical placement and maintenance of arteriovenous hemodialysis access. J Vasc Surg 2008;48:2S-25S.
4Sahasrabudhe P, Dighe T, Panse N, Patil S. Retrospective analysis of 271 arteriovenous fistulas as vascular access for hemodialysis. Indian J Nephrol 2013;23:191-5.
5Rayner HC, Pisoni RL, Bommer J, Canaud B, Hecking E, Locatelli F, et al. Mortality and hospitalization in haemodialysis patients in five European countries: Results from the Dialysis Outcomes and Practice Patterns Study (DOPPS). Nephrol Dial Transplant 2004;19:108-20.
6Manns B, Tonelli M, Yilmaz S, Lee H, Laupland K, Klarenbach S, et al. Establishment and maintenance of vascular access in incident hemodialysis patients: A prospective cost analysis. J Am Soc Nephrol 2005;16:201-9.
7Jennings WC, Kindred MG, Broughan TA. Creating radiocephalic arteriovenous fistulas: Technical and functional success. J Am Coll Surg 2009;208:419-25.
8Dageforde LA, Harms KA, Feurer ID, Shaffer D. Increased minimum vein diameter on preoperative mapping with duplex ultrasound is associated with arteriovenous fistula maturation and secondary patency. J Vasc Surg 2015;61:170-6.
9Brescia MJ, Cimino JE, Appel K, Hurwich BJ. Chronic hemodialysis using venipuncture and a surgically created arteriovenous fistula. N Engl J Med 1966;275:1089-92.
10Lauvao LS, Ihnat DM, Goshima KR, Chavez L, Gruessner AC, Mills JL Sr. Vein diameter is the major predictor of fistula maturation. J Vasc Surg 2009;49:1499-504.
11Bashar K, Clarke-Moloney M, Burke PE, Kavanagh EG, Walsh SR. The role of venous diameter in predicting arteriovenous fistula maturation: When not to expect an AVF to mature according to pre-operative vein diameter measurements? A best evidence topic. Int J Surg 2015;15:95-9.
12Carrel A, Guthrie CC. Anastomosis of blood vessels by the patching method and transplantation of the kidney. JAMA 1906;47:1648-51.
13Quinones-Baldrich WJ, Memsic L, Ramming K, Hiatt J, Busuttil RW. Branch patch for arterialization of hepatic grafts. Surg Gynecol Obstet 1986;162:488-90.
14Williams L, Patselas T. The “vein mouth,” an alternative to the branch patch technique for arteriovenous anastomosis. J Am Coll Surg 2009;209:793-4.
15Bharat A, Jaenicke M, Shenoy S. A novel technique of vascular anastomosis to prevent juxta-anastomotic stenosis following arteriovenous fistula creation. J Vasc Surg 2012;55:274-80.
16Van Canneyt K, Pourchez T, Eloot S. Haemodynamic impact of anastomoses size and angle in side to end arteriovenous fistulae: A computer analysis. J Vasc Access 2010;11:52-8.
17Haimov M, Baez A, Neff M, Slifkin R. Complications of arteriovenous fistulas for hemodialysis. Arch Surg 1975;110:708-12.
18Khavanin Zadeh M, Gholipour F, Naderpour Z, Porfakharan M. Relationship between vessel diameter and time to maturation of arteriovenous fistula for hemodialysis access. Int J Nephrol 2012;2012:942950.
19Mousa AY, Dearing DD, Aburahma AF. Radiocephalic fistula: Review and update. Ann Vasc Surg 2013;27:370-8.