What is an Ellipsys Fistula?
An Ellipsys fistula is a minimally invasive type of arteriovenous (AV) fistula, a direct connection between an artery and a vein, created using the Ellipsys Vascular Access System. This innovative endovascular procedure is a modern alternative to traditional open surgery for patients with end-stage renal disease (ESRD) who require hemodialysis. Unlike open surgery, which involves larger incisions and sutures, the Ellipsys method creates the fistula through a single needle stick by using a specialized catheter and low-power thermal energy. The goal is to provide a durable and reliable vascular access point for dialysis, which involves filtering waste and excess fluid from the blood.
Patient Eligibility and Preparation
To ensure a successful procedure, healthcare providers carefully evaluate patient eligibility and conduct necessary preparations. Candidates for an Ellipsys fistula are typically patients with ESRD who have suitable vessel anatomy in their arm.
Pre-Procedure Mapping
Before the procedure, a healthcare team performs a detailed ultrasound examination to map the arteries and veins in the arm. This mapping is crucial for identifying suitable vessels for the fistula creation. For the Ellipsys system, the optimal site is often in the proximal forearm, connecting the proximal radial artery to an adjacent deep communicating vein. The mapping confirms vessel size and proximity, with specific criteria such as a minimum vessel diameter and a maximum distance between the artery and vein.
Before the Procedure
Patients will be advised on specific preparations to ensure their safety and a smooth procedure. This may include:
- Disclosing all medications and allergies to the medical team. Blood-thinning medications, such as aspirin or clopidogrel, may need to be temporarily stopped for a period before the procedure.
- Refraining from eating or drinking after midnight on the day of the procedure, as per the physician's instructions.
- Arranging for transportation home, as sedatives or anesthesia will prevent the patient from driving.
How is an Ellipsys Fistula Done? The Step-by-Step Procedure
The Ellipsys procedure is performed in an outpatient setting and typically takes less than 30 minutes.
Anesthesia and Access
The procedure begins with the patient lying down, and the target arm is sterilized and draped. The physician administers local anesthesia to numb the area, keeping the patient awake but comfortable. Under continuous ultrasound guidance, a small micropuncture needle is used to gain single access to a vein in the elbow region.
Catheter Positioning
A guidewire is threaded through the needle and advanced into the vein. The Ellipsys catheter is then passed over the guidewire into the vessel. With the tip of the catheter positioned inside the proximal radial artery, the device is gently pulled to engage and approximate the artery and the adjacent perforating vein walls. The device ensures proper alignment and proximity of the two vessels before activation.
Vessel Fusion
Once the artery and vein walls are properly aligned, the Ellipsys catheter is activated to deliver low-power thermal energy. This energy, combined with pressure from the device, creates a permanent anastomosis by fusing the walls of the blood vessels together, creating a permanent connection. No sutures or implants are used in this process.
Post-Creation Steps
After the anastomosis is successfully created, the catheter and sheath are removed. Gentle pressure is applied to the access site to achieve hemostasis, and a small adhesive bandage is placed over the puncture. The patient can then be moved to a recovery area for monitoring before discharge.
Ellipsys vs. Traditional Surgical AV Fistula: A Comparison
| Feature | Ellipsys (Endovascular) Fistula | Traditional Surgical Fistula |
|---|---|---|
| Invasiveness | Minimally invasive; requires only a single needle puncture. | Invasive; requires a surgical incision, typically 2–4 inches long. |
| Sutures | None needed; uses thermal energy to fuse vessel walls. | Requires sutures to manually connect artery and vein. |
| Scarring | Minimal to no scarring, leaves only a small mark similar to a blood draw. | Leaves a noticeable scar from the surgical incision. |
| Recovery Time | Faster recovery, with most patients resuming normal activities within 24 hours. | Longer recovery period, often with more post-operative pain and restrictions. |
| Procedure Time | Quick; typically takes less than 30 minutes. | Longer; can take 1–2 hours. |
| Maturation | Faster maturation time, with some studies suggesting readiness for use in 4–6 weeks. | Slower maturation, usually taking 2–3 months or longer. |
| Re-intervention | Secondary interventions may be needed for maturation, but overall intervention rates can be lower in the long term compared to surgical fistulas. | May require additional interventions for maturation or patency maintenance. |
Benefits of the Minimally Invasive Ellipsys Procedure
There are numerous benefits associated with the Ellipsys endovascular procedure over traditional open surgery for AV fistula creation.
- Reduced Trauma and Scarring: The minimally invasive approach causes less trauma to the surrounding tissue and leaves minimal to no scarring, resulting in a better cosmetic outcome.
- Faster Recovery: Patients experience less post-procedure pain and can return to their daily routines much faster than with surgical fistula creation.
- Improved Long-Term Outcomes: Studies have shown high success and patency rates for Ellipsys fistulas, comparable to or even better than surgical fistulas in some cases.
- No Foreign Implants: The procedure fuses the natural vessel walls and does not involve leaving any foreign materials or implants inside the body.
- Outpatient Convenience: The procedure is performed in an outpatient setting, allowing patients to go home the same day.
- Reduced Catheter Dependence: The faster maturation of Ellipsys fistulas can reduce or eliminate the need for a central venous catheter, which carries a higher risk of infection and complications.
Risks and Considerations
While generally safe, the Ellipsys procedure, like any medical intervention, carries some risks. These include:
- Failure to Mature: Some fistulas may fail to mature sufficiently for dialysis, potentially requiring additional procedures or alternative access.
- Stenosis or Narrowing: A narrowing of the vein near the anastomosis can occur, which may require angioplasty to treat.
- Bleeding and Hematoma: Minor bleeding, bruising, or the formation of a hematoma (a collection of blood under the skin) at the puncture site can occur.
- Infection: Although the risk is low due to the minimally invasive nature, any procedure that breaks the skin carries a risk of infection.
- "Steal Syndrome": In rare cases, blood flow can be diverted away from the hand, leading to coldness, numbness, or pain.
- Thrombosis: The formation of a blood clot in the fistula can slow or block blood flow.
Recovery and Post-Procedure Care
Following the Ellipsys procedure, patients are given clear instructions to aid in recovery and maturation.
- Initial Recovery: Most patients spend a brief recovery period of 60-90 minutes before being discharged. They are advised to rest and keep the arm elevated to minimize swelling. For the first 24 hours, strenuous activity, heavy lifting, and driving should be avoided.
- Fistula Monitoring: Patients are taught how to check for the "thrill," a rhythmic vibration or buzzing sensation over the fistula, which indicates proper blood flow. Any changes in the thrill, or signs of infection such as redness, swelling, or pus, should be reported immediately.
- Maturation Process: The maturation of the fistula—the process of the vein enlarging and strengthening—typically takes 2–3 months, though some can mature faster. Regular exercise with a squeeze ball is often recommended to help accelerate this process.
- Ongoing Care: For long-term success, patients must protect their access site by avoiding tight clothing, jewelry, or blood pressure cuffs on the access arm and should not lift heavy objects with that arm.
Conclusion
For patients requiring hemodialysis access, the Ellipsys endovascular procedure represents a significant advancement over traditional surgery. By leveraging a minimally invasive, catheter-based approach that uses thermal energy, it creates a functional AV fistula with less trauma, faster recovery, and minimal scarring. While requiring careful patient selection and monitoring, studies indicate high success rates and comparable long-term patency to surgical fistulas. As a safe and effective option, the Ellipsys procedure is helping to improve the vascular access journey for many individuals with end-stage renal disease. For more information on the clinical trials and efficacy of this procedure, refer to entries on ClinicalTrials.gov.
