A transplanted kidney doesn’t go where your original kidneys sit. Instead, surgeons place it much lower, in the pelvis, tucked into a space called the iliac fossa, just above your groin on either side. Your original kidneys, located higher up near the back of your ribcage, almost always stay right where they are.
Where Exactly the New Kidney Sits
The standard placement is the right iliac fossa, a shallow, bowl-shaped area of your pelvis. If you put your hand on your lower abdomen, a few inches in from your right hip bone, you’re roughly over the spot. The kidney is placed in a retroperitoneal position, meaning it sits behind the membrane that lines your abdominal cavity rather than inside it. This keeps it separated from your intestines and other abdominal organs, which lowers the risk of complications like bowel obstruction.
The right side is preferred for a first transplant because the blood vessels there are slightly easier to access surgically. If a second transplant is ever needed, it typically goes in the left iliac fossa using the same technique. A third transplant would go back on the right side but positioned a bit higher.
Because the kidney sits so close to the surface of your abdomen, you may actually be able to feel it through your skin after surgery. Some recipients notice a firm, smooth shape in their lower abdomen, and doctors routinely check on the transplant by pressing on this area during follow-up visits.
How the Surgeon Connects It
The incision is a curved cut in the lower abdomen, known as a Gibson incision, running roughly from the hip toward the pubic area. Through this opening, the surgeon connects the donor kidney’s blood vessels to the large blood vessels in your pelvis. The kidney’s artery is stitched to your external iliac artery (the vessel that carries blood down to your leg), and the kidney’s vein is connected to the external iliac vein running alongside it. These connections are what allow blood to flow through the new kidney immediately.
The final step is attaching the donor kidney’s ureter, the tube that carries urine from the kidney, directly into your bladder. Surgeons tunnel it through the bladder wall at an angle, which creates a natural valve effect that prevents urine from flowing backward into the new kidney. The entire surgery typically takes three to four hours.
What Happens to Your Original Kidneys
In most cases, nothing. Your native kidneys stay in place even though they’re no longer working well. Removing them would add unnecessary surgical risk and recovery time, and they don’t interfere with the transplanted kidney’s function. Over time, native kidneys that have stopped working tend to shrink, especially during the first year after transplant.
There are exceptions. People with polycystic kidney disease sometimes need one or both native kidneys removed because the kidneys can grow so large they cause chronic pain, bleeding, or infections, or simply don’t leave enough room for the transplant. The most common reasons for removal before transplant are recurrent bleeding (about 29% of cases), lack of physical space (25%), and back pain severe enough to affect daily life (23%). Some transplant centers remove polycystic kidneys routinely to make room, while others take a wait-and-see approach, since the evidence suggests native kidney volume often decreases on its own after transplant.
How Quickly the New Kidney Starts Working
If the kidney comes from a living donor, it often starts producing urine within minutes of being connected to your blood supply. You may literally see urine output while still in the operating room. Kidneys from deceased donors take longer to “wake up” because they’ve been without blood flow for a longer period during transport and preservation.
Delayed function, where the kidney doesn’t produce adequate urine right away and temporary dialysis is needed, is common with deceased donor kidneys. In one large study, about 59% of deceased donor recipients experienced this delay. The typical duration was around 10 days, and 95% of cases resolved within four weeks. This doesn’t mean the transplant failed. It’s a temporary phase while the kidney recovers from the stress of the process.
Long-Term Outlook
Kidney transplants have strong survival rates. For living donor kidneys, one-year graft survival is around 97%, and five-year survival is approximately 87 to 88%. Deceased donor kidneys perform slightly lower, with about 92% functioning at one year and 76 to 78% still working at five years, according to the most recent national data from the U.S. Renal Data System. The gap between living and deceased donor outcomes has narrowed over the decades but remains meaningful.
The transplanted kidney’s position in the pelvis, closer to the surface than your original kidneys ever were, makes it easier to monitor. Doctors can feel the kidney during exams, and ultrasound imaging is straightforward because there’s less tissue between the skin and the organ. If there’s ever a problem with rejection or blood flow, this accessible location helps catch it early.