In Greek mythology, Prometheus was sent to feed an eagle his liver, with the belief that the remnants of the liver would grow back overnight for the mythical eagle to gorge again. Whether Prometheus’s liver grew back or not, we don’t know. But in evidence-based medicine, liver is the only organ in the body that can regenerate (replace lost or injured tissue) as a reparative process following surgery.

This regenerative power of the liver makes it possible for surgeons to perform liver surgeries, including partial hepatectomy, living donor liver transplantation and reduced-size liver transplantation. Doctors are aware that the remaining portion of the liver will continue to grow in size till the liver mass is totally restored.

In most patients, the liver continues to function normally after surgery. However, if the remnant of the liver is less than 20% of the original volume of the organ, the bandwidth of liver function might be inadequate for sustaining the body’s metabolic, synthetic and detoxifying requirements. This could lead to post-resection liver failure.

Can Liver Grow Back After Surgery

What happens when the liver regenerates?

Our liver primarily performs three functions. It acts as a blood filter, a metabolic processor and a protein factory. Whenever blood flow is compromised to one section of the liver, it will compensate for the deficit by growing bigger, provided the remaining part of the organ is healthy.

The cells growing larger (known as ‘hypertrophy’) are not immediately ready to perform the full range of functions of the liver. Nonetheless, in quick time, sometimes in a matter of days, they mature and pick up the mantle of the entire gamut of roles which the removed cells used to perform.

In many liver cancer surgery patients, with even 50% of their liver removed, the remaining liver tissue often grows back to its earlier volume, sometimes even in just a month post-surgery. The bilirubin count is generally used to track liver function. It shoots up when the liver isn’t functioning at its optimum level as bile accumulates.

When the bilirubin count rises after surgery and then trickles down to normal levels later, doctors know the liver is functioning well. Even healthcare professionals are sometimes surprised by how well and how swiftly the liver can regain its normal size and functions following liver surgery.

Factoring regrowth into treatment plan

Surgeons are conscious of this regrowth potential of the liver and the treatment protocols post-surgery would be tailored, keeping this in mind. When surgery is being performed to remove cancer cells from the stomach, intestines, pancreas, kidney or lungs, the doctors are always extremely cautious about how much tissue they can junk, since these organs can’t regenerate.

However, with liver surgery, while there’s always the cardinal aim to remove as little as possible, the regrowth leeway is always there. So, doctors usually plan their surgeries in a manner that while removing the necessary portion of the liver, room is kept for at least 30% of the resected tissue to grow back. A computer software is used in this estimation which measures the liver’s volume vis-à-vis the patient’s body size.

While the magic capacity of the liver to regenerate makes extensive liver resection procedures possible, there’s still the ominous portent of post-hepatectomy liver failure (PHLF), one of the deadliest complications of liver surgery. Hence, doctors try to leave no stone unturned in their efforts to clinically establish reliable prognostic factors post-surgery, before the OT lights are switch on.