Overview
Definition:
A basilic vein transposition arteriovenous (AV) fistula is a type of surgically created access for hemodialysis
It involves connecting the cephalic vein or brachial artery to a transposed basilic vein in the arm, typically in the forearm, to create an arterialized venous segment suitable for repeated cannulation.
Epidemiology:
AV fistulas are the preferred initial access for hemodialysis in end-stage renal disease (ESRD) patients due to their longevity and lower complication rates
Basilic vein transposition is a common technique when autogenous cephalic vein fistulas are not feasible or have failed
Incidence relates directly to the prevalence of ESRD requiring dialysis.
Clinical Significance:
The creation and maintenance of an AV fistula are critical for successful and long-term hemodialysis
A well-functioning basilic vein transposition fistula provides durable access, reducing the risk of infection, thrombosis, and steal syndrome compared to grafts or catheters, thereby improving patient outcomes and quality of life.
Indications
Patients Requiring Hemodialysis:
Patients with end-stage renal disease (ESRD) who require chronic hemodialysis and are expected to need vascular access for more than 12 months.
Failure Of Other Access Options:
When autogenous cephalic vein fistulas are not suitable due to inadequate vein size, tortuosity, or previous failed attempts.
Contraindications For Grafts:
Patients with a history of previous graft infections or those deemed at high risk for graft complications, where an autogenous option is preferred.
Preoperative Preparation
Patient Evaluation:
Thorough assessment of venous anatomy using physical examination and duplex ultrasonography to identify suitable veins (basilic vein) and arteries
Assess for existing vascular access, significant scarring, or prior interventions.
Vein Mapping:
Detailed mapping of the basilic vein, evaluating its diameter, depth, course, and patency
The presence of adequate arterial inflow is also crucial
Consideration of dominant arm for future AV fistula creation.
Medical Optimization:
Review of medications, particularly anticoagulants or antiplatelet agents
Ensure patient is medically fit for surgery
Counseling on the procedure, risks, benefits, and post-operative care.
Procedure Steps
Surgical Approach:
A curvilinear incision is typically made along the medial aspect of the forearm
The basilic vein is identified, mobilized from its deep position, and dissected free from surrounding tissues, preserving its continuity.
Arterialization Anastomosis:
An end-to-side anastomosis is created between a suitable artery (e.g., radial artery or a branch of the brachial artery) and the distal end of the mobilized basilic vein
Careful attention is paid to tension-free anastomosis.
Venous Anastomosis:
The proximal end of the transposed basilic vein is then anastomosed to a more proximal vein segment, creating a loop or antegrade flow
Alternatively, in forearm fistulas, the transposed basilic vein itself is used as the efferent limb.
Hemostasis And Closure:
Meticulous hemostasis is achieved
The transposed vein is positioned superficially for easier cannulation
The incision is closed in layers, ensuring adequate blood flow through the fistula and minimizing risk of hematoma.
Postoperative Care
Early Monitoring:
Immediate postoperative assessment for bruit and thrill, indicating adequate flow
Monitor for signs of bleeding, hematoma, or venous hypertension in the distal limb
Doppler ultrasound may be used to confirm patency.
Maturation Period:
The fistula requires a maturation period of 4-6 weeks (sometimes longer) before it can be used for dialysis
During this time, the vein dilates and thickens due to arterialization.
Cannulation Technique:
Once matured, the fistula is cannulated using specific AV fistula needles and techniques to promote outflow and minimize complications like aneurysm formation or stenosis
Rotation of cannulation sites is encouraged.
Long Term Monitoring:
Regular clinical assessment for signs of complications such as thrombosis, stenosis, infection, steal syndrome, or high-output heart failure
Periodic ultrasound evaluation may be necessary.
Complications
Early Complications:
Bleeding
Hematoma formation
Pseudoaneurysm at the anastomosis
Thrombosis of the fistula
Venous hypertension or limb swelling
Infection.
Late Complications:
Stenosis (at anastomosis or along the fistula)
Aneurysm formation (leading to rupture risk)
Steal syndrome (distal ischemia)
High-output heart failure
Persistent venous hypertension
Infection leading to fistula loss.
Prevention Strategies:
Meticulous surgical technique with tension-free anastomoses
Adequate vein mapping
Early detection and management of thrombosis or stenosis
Proper cannulation techniques
Prompt treatment of infection
Regular surveillance with duplex ultrasound.
Prognosis
Factors Affecting Prognosis:
Patient comorbidities (diabetes, peripheral vascular disease)
Quality of the native veins and arteries
Surgical technique
Patient compliance with post-operative care and monitoring
Development of early complications.
Outcomes:
When successful, a basilic vein transposition AV fistula can provide durable vascular access for many years, significantly improving the quality of life for ESRD patients
Primary patency rates are generally high, though secondary patency can be affected by interventions.
Follow Up:
Lifelong monitoring is required for patients with AV fistulas
Regular clinical examinations and, when indicated, duplex ultrasound assessments are essential to detect and manage complications proactively, ensuring continued adequate dialysis access.
Key Points
Exam Focus:
Understand the surgical steps, indications, and common complications of basilic vein transposition
Differentiate it from other AV access types
Know the maturation period and criteria for use.
Clinical Pearls:
The transposed basilic vein is placed subcutaneously to facilitate cannulation
Watch for distal venous congestion and signs of steal syndrome post-operatively
Early thrill and bruit are indicators of patency.
Common Mistakes:
Failure to adequately map the basilic vein
Inadequate mobilization leading to tension on the anastomosis
Overlooked distal venous hypertension
Delayed diagnosis of thrombosis or stenosis
Improper cannulation technique.