Bilateral carotid-jugular arteriovenous graft implantation in an ovine model is safe and durable for facilitation of arteriovenous graft innovation.
Publication Year:
2025
PubMed ID:
41189097
Funding Grants:
Public Summary:
More than 550,000 people in the United States need hemodialysis because they have end-stage kidney disease. To do hemodialysis, patients usually need a way for blood to flow easily in and out of their body. The first choice is usually a fistula, which connects an artery and a vein. But when a patient’s anatomy doesn’t allow a fistula to be created, doctors use an arteriovenous graft (AVG) instead.
Unfortunately, AVGs often don’t work well for long periods of time. They can become blocked, stop working, or get infected. Because of this, researchers are looking for better designs and better ways to test new grafts. In the past, studies using large animals had problems such as many complications and short follow-up times. This made it hard to truly understand how well the grafts worked.
This study focused on creating a safer and more reliable sheep model to test AVGs over a longer period of time. Eight female sheep were used. Each sheep received two AVGs—one on each side of the neck—connecting the carotid artery to the jugular vein. Surgeons placed both grafts through a single cut along the front of the neck. They used ringed PTFE grafts arranged in a “lazy-S” shape so the grafts wouldn’t pull, stretch, or kink when the sheep moved their necks.
After surgery, the sheep were checked every day for any problems. Ultrasound scans were done regularly for up to six months to see if the grafts remained open and working. At the six-month mark, the researchers performed more imaging tests and then removed the grafts to examine them closely.
All 16 graft surgeries were completed successfully. None of the sheep had major complications like stroke, infection, wound breakdown, graft failure at the connection site, or death. After six months, 75% of the grafts were still open, which is similar to the results seen in human patients.
Overall, this study shows that placing AVGs between the carotid artery and jugular vein in sheep is a safe, dependable model for long-term testing of new graft technologies.
Scientific Abstract:
Over 550 000 people in the U.S. require hemodialysis for management of end stage renal disease (ESRD). When anatomy restricts fistula creation, arteriovenous grafts (AVG) are implanted. AVGs have poor primary patency and high risk of infection, highlighting a need for better alternatives. Previous AVG large animal models were limited by high complication rates and short-term follow-up. This study investigates the safety and durability of an ovine bilateral carotid-jugular AVG model. Eight female sheep underwent bilateral carotid-jugular AVG implantation via a single longitudinal incision overlying the trachea. Ringed PTFE grafts were anastomosed in a "lazy-S" configuration to provide the laxity needed to prevent avulsion and minimize kinking with neck movement. Post-operatively, sheep were evaluated daily to monitor for complications. Duplex ultrasonography of the grafts was performed at regular intervals out to 6 months to evaluate patency. At 6 months, angiography and duplex was performed followed by explant for gross and histologic analysis. Technical success was achieved in 16 of 16 (100%) graft implants. No major complications, including stroke, anastomotic disruption, infection, wound breakdown, or death occurred. Primary patency of control PTFE grafts was 75% at 6 months, paralleling reported rates in humans. Bilateral carotid-jugular AVG implantation in sheep is a safe and durable model for self-controlled long-term evaluation of AVG conduit technology.
