Endovascular Arteriovenous Fistula Creation (EndoAVF)
Introduction to EndoAVF
An arteriovenous fistula (AVF) is a crucial component in hemodialysis treatment for patients with kidney failure. It’s a direct connection between an artery and a vein, typically in the arm, which allows for efficient blood flow during dialysis. While traditionally created through open surgery, advancements in medical technology have led to the development of the percutaneously (or “endovascularly”) created arteriovenous fistula (endoAVF).
Traditional AVF vs. EndoAVF
Traditionally, AVFs are created surgically by directly connecting an artery to a vein. This method, while effective, involves an incision followed by a surgical procedure. EndoAVF, in contrast, is a minimally invasive method that uses a catheter to create a connection between an artery and a vein from within the blood vessels. This innovative approach eliminates the need for a sizable surgical incision. This procedure is also less invasive than traditional surgery and typically has a shorter recovery time.
The EndoAVF Procedure
1. Vascular Mapping
- Before the procedure, a detailed ultrasound or other imaging technique is used to map the patient's vascular anatomy. This step is crucial to identify the optimal site for fistula creation, as well as whether EndoAVF creation is feasible.
- There are currently 2 devices on the market that can facilitate the percutaneous creation of an AVF- the WavelinQ™ and Ellipsys® systems. Your vascular surgeon will be able to evaluate and advise you on which is the more suitable system based on your anatomy.
2. Preparation and Anesthesia
- The procedure is usually performed under regional anaesthesia. This is administered by the anaesthetist, and ensures comfort and minimizes pain during the procedure.
3. Catheter Insertion
- Depending on the device used, there may be one or two catheters utilized.
- A small incision is made, usually in the wrist or elbow area, through which a catheter is inserted into the vein. In the case of the WavelinQ™ system, another catheter may be simultaneously inserted into an artery. These catheters are guided to the desired location using imaging technology.
4. Fistula Creation
- Once the catheters are in place, the devices are used to create a connection between the artery and vein, forming the fistula.
Specific devices and how they work
1. WavelinQ™ EndoAVF System
- The WavelinQ™ system uses two thin, magnetic catheters, one inserted into an artery and the other into a vein. These catheters are aligned using magnetic guidance.
- Once aligned, radiofrequency energy is applied to create a small hole, connecting the artery and vein, thus forming the fistula.
- This system offers flexibility in terms of the location of fistula creation, either in the forearm or upper arm, and is adaptable to different patient anatomies.
2. Ellipsys® Vascular Access System
- The Ellipsys® system uses a single catheter that is inserted into a vein near the elbow. The catheter is then advanced to the site where the vein and artery are close together.
- Using thermal energy, the device creates a connection between the artery and vein without the need for a second arterial access point.
- This system is noted for its simplicity and efficiency, often resulting in a quicker procedure and potentially less discomfort for the patient.
Benefits of EndoAVF
EndoAVF offers several advantages over traditional surgical methods:
- Minimally Invasive: Less traumatic for the patient, with smaller incisions (almost scarless).
- Quicker Recovery: Patients can often return to their normal activities sooner.
- Shorter surgical procedural time: The time taken for this procedure is generally faster than that of open surgery
- Reduced Complications: Lower risk of infection and other surgical complications like Steal Syndrome.
Potential Risks and Complications
Like any medical procedure, the EndoAVF procedure carries some risks, although they are generally less than traditional surgery. These include infection, bleeding, and the possibility of the fistula not maturing properly. It is important to discuss these risks with your vascular surgeon.
Aftercare and Maintenance
After an EndoAVF procedure, patients will need to follow specific aftercare instructions to ensure the fistula matures correctly and is ready for use in hemodialysis. This includes keeping the site clean, monitoring for signs of infection, and regular check-ups to assess for maturation.
Eligibility and Considerations
Not all patients are suitable candidates for endoAVF. Factors such as the patient’s vascular anatomy, overall health, and specific medical conditions will influence eligibility.
Conclusion
The EndoAVF procedure is one that is relatively new to this part of the world. It presents a promising alternative to traditional AVF creation, offering a less invasive procedure with quicker recovery times. However, it is important to weigh the benefits against potential risks and discuss them thoroughly with your vascular surgeon.
Dr. Lim is adept in performing this procedure with either the WavelinQ™ or Ellipsys® devices, and will be able to evaluate and advise you appropriately, should you be a suitable candidate for this.
FAQ about EndoAVF
It varies, but it typically takes a few weeks to a few months for the fistula to mature.
The procedure is usually performed under regional anesthesia, so pain during the procedure is minimal. There may be some discomfort post-procedure, which can usually be managed with over-the-counter pain relief.
Eligibility for endoAVF depends on individual patient factors, such as size of the superficial and perforating veins in the arm. Not all patients are suitable candidates.
