OLT stands for orthotopic liver transplantation, a surgical procedure in which a diseased liver is removed and replaced with a healthy liver (or a portion of one) from a deceased or living donor. The term “orthotopic” means the new liver is placed in the same anatomical position as the original. This distinguishes it from heterotopic transplantation, where a donor organ is placed in a different location in the body. OLT is the standard form of liver transplant performed worldwide.
Why OLT Is Performed
OLT is reserved for people whose liver disease has progressed to the point where no other treatment can restore function. The most common reasons include chronic liver failure from cirrhosis, which gradually shuts down the liver over months or years, and acute liver failure, where the organ deteriorates rapidly. Primary liver cancers, including hepatocellular carcinoma and cholangiocarcinoma, also qualify patients for transplant when the tumor meets certain size and staging criteria. In some cases, cancer that has spread to the liver from another organ, such as colorectal cancer, may also be an indication.
How Patients Are Prioritized
In the United States, the allocation system for donor livers relies on a scoring tool called MELD (Model for End-Stage Liver Disease). The current version, MELDNa, has been used to determine transplant priority since 2016. It calculates a score based on four blood test results: bilirubin (a marker of how well the liver processes waste), creatinine (a measure of kidney function, which liver disease often impairs), INR (how quickly the blood clots), and sodium levels. Higher scores indicate more urgent need, and organs go to the sickest patients first. This system replaced older methods that relied more heavily on subjective clinical judgment and time spent on the waiting list.
What Happens During the Surgery
OLT is one of the most complex operations in surgery and typically takes between six and twelve hours. The procedure has three broad phases: removing the diseased liver, connecting the donor liver’s blood vessels, and reconstructing the bile duct.
Once the native liver is taken out, the surgeon completes four separate connections between the donor liver’s blood vessels and the recipient’s. These include two connections to the large vein that carries blood back to the heart, one to the vein that brings blood from the intestines to the liver, and one to the artery that supplies the liver with oxygen-rich blood. Each connection must be precisely sutured to avoid narrowing or clotting, which could starve the new liver of blood flow.
After the blood supply is established, the surgeon reconnects the bile duct, the tube that carries digestive fluid from the liver to the intestine. The preferred approach is a direct duct-to-duct connection. When the anatomy doesn’t allow that, the surgeon creates a new pathway by attaching the bile duct directly to a loop of small intestine.
Complications After OLT
Biliary complications are among the most common problems after liver transplant, affecting 10 to 30 percent of recipients who receive a whole organ. These include bile leaks, where fluid escapes from the connection site, and strictures, where the bile duct narrows and blocks drainage. Biliary complications carry a mortality rate of up to 10 percent, making early detection critical. Patients are monitored closely with blood tests and imaging in the weeks and months following surgery.
Blood clotting in the hepatic artery, the vessel that supplies oxygen to the new liver, is another serious risk. Because the bile ducts depend entirely on arterial blood for their oxygen supply, a clot can damage both the artery and the bile duct system at once. Rejection, where the immune system attacks the donor liver, is an ongoing concern that can occur days, months, or even years after transplant.
Lifelong Medication After Transplant
After OLT, your immune system will recognize the new liver as foreign tissue and attempt to destroy it. To prevent this, you’ll take immunosuppressive medications for the rest of your life. The cornerstone of treatment is a class of drugs called calcineurin inhibitors, with tacrolimus being the most widely used. These drugs dial down the immune response enough to protect the donor liver without leaving you completely defenseless against infections.
Most transplant centers use a combination approach. A typical regimen pairs a calcineurin inhibitor with a low-dose steroid, such as prednisolone. Some patients receive a third medication, an antimetabolite, which further suppresses immune cell activity. Over time, doctors often taper the steroid dose down to as little as 5 milligrams per day, though the calcineurin inhibitor remains a permanent part of daily life. The exact combination and dosing are adjusted based on blood levels and how well the new liver is functioning, with more frequent monitoring in the first year and periodic check-ins after that.
Living with these medications means a higher susceptibility to infections and certain cancers over the long term, which is why transplant recipients undergo regular screenings and blood work indefinitely. Despite these trade-offs, OLT transforms the prognosis for people with end-stage liver disease, with five-year survival rates generally exceeding 70 percent.