A kidney transplant can be a life-saving procedure, offering patients with end-stage renal disease a second chance at life. However, for some patients, the very blood vessels that should support a new kidney are severely hardened and blocked due to calcification. Arteries function like highway roads that carry blood flow throughout the body, including a newly transplanted kidney.  When these roads are obstructed, the stream can slow and eventually halt.  For some patients, the arteries that provide blood flow to a new kidney may be blocked.

While this condition can be a significant obstacle, advancements in surgical techniques are changing the possibilities for patients who might otherwise have limited options due to the condition of their blood vessels.  At UI Health, the Kidney Transplant Program takes on cases that other transplant programs may turn away, using interventional approaches to give more patients a path to kidney transplantation.

Understanding kidney disease?

Doctors often detect chronic kidney disease (CKD) through blood tests and urine analysis during routine check-ups. Without treatment, CKD can progress to kidney failure, where the kidneys can no longer filter waste and excess fluid from the body.

When the patient’s disease worsens, a kidney transplant becomes the best alternative by replacing the damaged kidney with a healthy one from a living or deceased donor.

At UI Health, specialists like Dr. Sajid Ansari, a Nephrologist and assistant professor of clinical medicine at the University of Illinois Chicago (UIC), provide transplants to help patients regain kidney function and improve their quality of life. “I don’t tell patients I am a kidney doctor. I tell them I help people regain their lives,” Dr. Ansari said. “When people have advanced kidney disease, they are hooked to dialysis. So they are unable to work, travel, or see family. When we give people kidney transplants, we give all of this back to them. They are healthier, stronger, and their hormones get better.”

What are calcified vessels?

However, a roadblock that patients seeking a kidney transplant often face is the natural hardening of blood vessels over time, which is known as vascular calcification. As calcium builds up in the walls of these vessels, they lose their flexibility and become more rigid and narrow, making it difficult for blood to flow freely.

Restricted circulation complicates transplant surgery, as the new kidney relies on strong, open vessels to connect and function successfully. Without proper blood flow, the new kidney may not receive the oxygen and nutrients it needs, putting the transplant at risk.

As part of the first visit evaluation, doctors use a CT angiography, a procedure that combines a CT scan with a special dye that is injected. This test allows doctors to closely examine the vessels and surrounding tissues, assessing blockages or other issues that could affect transplant success. “This allows us to see the caliber of the vessels and determine the next steps before transplantation,” stated Dr. Ansari.

What patients are at risk for vascular calcification?

While individuals with a family history of vascular disease may be more susceptible to developing vascular calcification, doctors and surgeons hope to bring awareness to several other key causes that increase the risk.

Studies have indicated that smoking progresses calcified build-up in the arteries. Another key risk factor is Type 2 diabetes. Prolonged high blood sugar levels can damage blood vessel walls over time. Additionally, diabetes contributes to atherosclerosis—a condition in which plaque accumulates in the arteries—further compounding the risk of restricted blood flow.

Finally, kidney failure itself can cause an abnormal build-up of calcium and phosphate in the body. “When you have kidney failure, you cannot eliminate phosphate through your kidneys,” explained Dr. Stephen Bartlett, a transplant surgeon at UI Health. “As phosphate builds up in your body, it combines with calcium, causing deposits to form in your tissues.” Similarly, while dialysis is lifesaving, it can also disrupt the body’s natural balance of calcium and phosphate, contributing to the same harmful build-up over time.

What is the impact on kidney transplant eligibility?

What happens when a patient who has been waiting for years for a matching kidney finally finds a match, only to discover that there has been a build-up of calcium in their blood vessels?

“Most transplant centers will see the calcification and summarily reject the patient,” stated Dr. Bartlett. “In most transplant programs, even a modest amount will lead to a rejection.”

Many see that the risks do not outweigh the benefits. Severe blood flow obstruction, especially to a new kidney, leads some programs to believe that transplant failure is inevitable.

Additionally, because calcified vessels are more fragile and less flexible, they present significant challenges during surgery. The hardening of the blood vessel walls makes it difficult for surgeons to navigate around them properly, increasing the likelihood of unintended tears or damage. These complications make the surgical process more complex, which is why many transplant centers deny patients the surgery if calcium traces are found.

However, surgeons like Dr. Bartlett pride themselves on the surgical capabilities at UI Health. “The reason we can accept these patients is because we have the surgical techniques and the surgeons to manage calcified vessels that other centers may not have.”

UI Health accepts all patients.

For the kidney transplant program at UI Health, it is not a matter of if a transplant will be performed but rather what necessary steps are taken to ensure a patient is given their lifesaving replacement.

“When there are calcifications, it boils down to our expertise,” said Dr. Ansari. “We have surgeons who are vascular-trained, surgeons who can do angioplasty (a minimally invasive approach to open arteries), and surgeons who can do bypasses in the narrowing of the vessels by inserting a small graft.”

At UI Health, surgeons work to ensure that every patient has the opportunity for a successful kidney transplant, overcoming the challenges of vascular calcification.

“I cannot change a patient’s age or how long they’ve been on dialysis,” Dr. Ansari continued. “Everything else I can work with. I can regulate their cholesterol levels, educate patients on kidney disease, and advise them on lifestyle changes such as workouts and diets – all to reduce the possibilities of complications during surgery.”

By combining the expertise of health professionals, vascular specialists, and transplant surgeons, the kidney program team can develop personalized treatment plans that address complex vascular issues head-on. This collaborative approach ensures that even patients with severe calcification can be prepared for a transplant with the best possible outcomes.

If you are interested in a referral for a kidney transplant evaluation or would like more information about our program, please email us at kidney transplant or call 312.996.6771.