A liver resection is surgery to remove part of the liver, typically to eliminate a tumor or diseased tissue. It’s one of the few organs in the body that can regrow to its original size after a portion is removed, which makes this surgery possible even when a large section needs to come out. Healthy liver tissue can regenerate up to two-thirds of its volume, often reaching full size within about three months.
Why Liver Resection Is Performed
The most common reason for liver resection is cancer. Tumors that start in the liver itself, called hepatocellular carcinoma, and cancers that have spread to the liver from the colon or rectum (colorectal liver metastases) are the two leading indications. Bile duct cancers that form inside the liver are another, less common reason.
Not all liver resections involve cancer. Benign growths can also require surgery when they cause symptoms, particularly pain or pressure from their size. These include blood vessel tumors called hemangiomas, a type of cell overgrowth known as focal nodular hyperplasia, and liver adenomas. In these cases, the goal is symptom relief and preventing potential complications like bleeding.
How Surgeons Decide How Much to Remove
The liver is divided into eight distinct segments, each with its own blood supply and drainage. This anatomy allows surgeons to remove specific segments while leaving the rest fully functional. A “minor” resection typically involves removing fewer than three segments, while a “major” resection removes three or more, sometimes an entire left or right half of the liver.
The critical factor in planning is the future liver remnant: the percentage of healthy liver that will remain after surgery. For a patient with a normal, healthy liver, surgeons generally consider it safe to proceed when at least 20% of the liver volume will be left behind. That threshold climbs to 30 to 40% for patients with significant fatty liver disease, and to 50% or more for patients with cirrhosis, because a damaged liver regenerates more slowly and less reliably.
When imaging shows the remnant would be too small, surgeons can use a pre-operative technique called portal vein embolization. This involves blocking blood flow to the side of the liver that’s going to be removed, which tricks the remaining side into growing larger before the actual surgery takes place. On average, this procedure increases the future remnant by about 38%, often making a previously impossible resection safe to perform. It’s typically done several weeks before the main operation to give the liver time to respond.
Open vs. Minimally Invasive Surgery
Liver resection can be done through a large abdominal incision (open surgery) or through several small incisions using a camera and specialized instruments (laparoscopic surgery). Both approaches achieve the same goal, and blood loss during the operation is comparable between the two.
The difference shows up in recovery. In studies comparing the two approaches, patients who had laparoscopic surgery started walking within about two days after the operation, compared to nearly six days for open surgery. They resumed eating on a similar timeline. Hospital stays averaged 13 days for laparoscopic patients versus 20 days for open surgery. Not every tumor is accessible through the minimally invasive approach, though. Location, size, and the number of tumors all factor into which technique is appropriate.
What Recovery Looks Like
The first few days after surgery focus on managing pain, monitoring liver function, and getting you moving. Blood sugar is closely watched because the liver plays a central role in regulating it, and intravenous glucose is typically given until you’re eating enough on your own.
Nutrition matters more than usual during recovery. The regenerating liver has high metabolic demands, so the early post-operative diet emphasizes adequate protein, particularly branched-chain amino acids, which support liver cell rebuilding. A diet that includes medium-chain fats (the kind found in coconut oil, for example) is easier for the recovering liver to process than standard dietary fats. Optimizing nutrition before surgery also makes a measurable difference in how smoothly the post-operative period goes.
The liver’s regrowth process happens in three phases: an initial activation phase where cells receive signals to start dividing, a proliferation phase where the bulk of regrowth occurs, and a termination phase where the liver senses it has reached its target size and stops. One of the key triggers is the change in blood flow after surgery. With fewer liver segments to pass through, blood pressure within the liver’s portal vein increases, and the resulting physical force on blood vessel walls kicks off a cascade of growth signals. In humans, the liver typically reaches its full restored volume around three months after a right or left lobe resection.
Risks and Complications
The most serious risk specific to this surgery is post-hepatectomy liver failure, which occurs when the remaining liver can’t keep up with the body’s needs. It’s defined by rising levels of bilirubin (a waste product the liver clears) and impaired blood clotting ability, assessed from about five days after surgery onward. This is relatively uncommon when the future liver remnant has been carefully calculated beforehand, which is why pre-operative imaging and volume assessments are so important.
Other potential complications include bile leaks, where digestive fluid escapes from the cut surface of the liver, and bleeding. Infection at the surgical site or within the abdomen is also possible. The overall complication rate depends heavily on the extent of the resection, the patient’s baseline liver health, and which surgical approach is used.
Survival After Liver Resection for Cancer
For colorectal cancer that has spread to the liver, resection remains the standard treatment with the strongest track record. Five-year survival rates range from 15% to 58%, a wide range that reflects how much outcomes depend on the number and size of tumors, how well they respond to chemotherapy, and whether they can be completely removed with clear margins. Patients with a single small metastasis on one side of the liver tend to fall toward the higher end of that range, while those with multiple tumors in both lobes face longer odds. Even so, resection offers a chance at long-term survival that few other treatments can match for this type of cancer.