Surgeons usually remove 40–60% in living liver donation; adults get a right lobe, children often receive a smaller left segment.
People ask a simple question before they volunteer: how big a share of the liver does a living donor give? The answer sits above. The full answer needs context, because the goal is a graft that fits the recipient and leaves a healthy remnant for the donor. That balance drives the exact percentage.
How Much Liver Do Donors Give In Living Donation?
In adult-to-adult cases, the right lobe is common. That portion is usually a little more than half of total liver volume. In adult-to-child cases, surgeons favor a left-sided segment, which is much smaller. These patterns come from anatomy and blood flow, not from a one-size rule.
| Donor–Recipient Match | Graft Type | Typical % Removed |
|---|---|---|
| Adult donor → Adult recipient | Right lobe (segments 5–8) | 55–70% |
| Adult donor → Adult recipient | Left lobe (segments 2–4) | 35–45% |
| Adult donor → Child recipient | Left lateral segment (segments 2–3) | 15–25% |
| Large adult recipient | Right lobe with middle hepatic vein | ≈65–75% |
| Small adult recipient | Left lobe | ≈35–40% |
Ranges vary by center. Teams model the donor’s liver volume by CT or MRI, then match a graft size to the recipient’s body weight and disease state. The number that matters for donor safety is the remnant: surgeons plan to leave at least a third of the liver behind, and often more, based on quality and fat content.
Right Lobe Donation For Adult Recipients
The right lobe supplies more mass, which a full-size adult needs. Surgeons may include part of the middle hepatic vein to improve outflow when the recipient is large. That choice lifts the graft percentage but stays within safe ranges when the donor’s mapping shows strong collateral drainage.
Left Lobe And Left Lateral Segment For Smaller Recipients
For a petite adult or a child, a left-sided graft often fits better. The left lateral segment is a classic pick for children because it keeps the donor percentage low while giving the child enough liver to work with from day one.
How Surgeons Decide The Safe Share
Three checks guide the plan. These steps aim to give the recipient a liver that works on arrival and to keep the donor safe both short-term and long-term.
Remnant Liver Volume
Programs target a remnant of at least 30–35% of the donor’s total liver volume, adjusted for steatosis and overall health. A larger remnant gives more cushion when the liver is fatty or fibrotic. This threshold comes from decades of clinical data and is a bedrock planning number.
Graft-To-Recipient Weight Ratio (GRWR)
Teams estimate graft weight as a share of the recipient’s body weight. A GRWR near 0.8–1.0% or higher is a common target to reduce the chance of small-for-size syndrome. Centers may aim higher when portal pressures run high or the recipient is very ill.
Vascular And Biliary Mapping
CT angiography and MRCP map arteries, veins, and bile ducts. Surgeons pick the cut line that preserves clean inflow, outflow, and drainage for both people. When anatomy is tricky, the plan may shift from a right lobe to a left lobe or segment-sparing approach to keep risk down.
For readers who want the clinical source material that shapes those thresholds and choices, see the OPTN living donor evaluation guidance and the AASLD primer, “How Much Liver Is Enough?”.
What Percentage Is Typical In Real Cases?
Across large programs, adult recipients often receive a right-sided graft in the 55–70% band. Left-sided grafts for adults often sit near 35–45%. Children who receive a left lateral segment see donor percentages closer to 15–25%. A few scenarios push the number higher or lower, but those are planned exceptions shaped by imaging, blood tests, and intra-operative findings.
Why The Amount Varies
- Recipient size and illness. Bigger bodies need larger grafts. Severe portal hypertension drives surgeons to choose more mass.
- Donor liver quality. A fatty liver may need a larger remnant to keep recovery smooth for the donor.
- Anatomy. Extra arteries or unusual venous drainage can nudge the plan toward one lobe or the other.
- Center experience. Some teams favor left-lobe grafts for adults when anatomy and size allow, trading longer recipient recovery for a smaller donor resection.
Eligibility And Evaluation Snapshot
Not everyone can be a donor, and that protects both people. Programs screen for age, general fitness, and organ health. Exact cutoffs vary by center, but the themes are steady.
- Age and general health. Adults with steady blood pressure, no advanced heart or lung disease, and no active cancer are candidates. Many centers set an upper age limit, then judge case by case.
- Body mass and liver fat. A high BMI or heavy steatosis on imaging can delay or rule out donation until the liver looks leaner and lab values improve.
- Blood type and matching. ABO matching steers the pairing. Crossmatch rules are center-specific.
- Medications and habits. Teams review anticoagulants, herbal products, alcohol, and tobacco. Some items need a pause or a plan.
- Mental health and consent. Donors meet with an independent advocate. The goal is clear consent without pressure from family or timelines.
Recovery After Donation
The liver has a strong capacity to regrow after surgery. Volume returns fast in the first weeks and then slows. Most donors move from hospital care to home in about a week, then step back into daily routines over the next month or two. Full athletic effort takes longer, and timelines vary by person and by lobe.
| Timeframe | What Happens | Typical Activity Level |
|---|---|---|
| Week 1 | Hospital stay, pain control, walking laps, diet advances | Short walks, breathing exercises |
| Weeks 2–3 | Clinic checks, staples/clips out if used | Light chores, easy desk work |
| Weeks 4–6 | Liver volume often near ~80% of baseline | Return to office work; no heavy lifting |
| Months 2–3 | Volume and labs trend toward baseline | Resume workouts with clearance |
| Months 4–12 | Scars mature; energy fully rebounds | Full activity after surgeon’s green light |
That timeline is the general arc. Right-lobe donors may feel a longer dip in energy than left-lobe donors because of the larger resection. Laparoscopic techniques can shorten recovery for selected donors. Your team sets milestones based on imaging, lab trends, pain control, and personal goals.
Risks, Safety Checks, And Long-Term Outlook
No major surgery is risk-free. Living donors face wound issues, bile leaks, infections, blood clots, and rare events that require re-operation. Programs track outcomes and refine pathways to curb those risks. Centers screen donors carefully, repeat imaging when needed, and map bile ducts to reduce leaks.
Long-term health after donation is a common worry. Large cohort studies show most donors return to baseline life and work. A small share develops issues tied to scar tissue, hernias, or gallbladder removal. Teams keep follow-up clinics open for years and encourage donors to call early if something feels off.
What People Ask About Percentages
Can Someone Donate More Than Half?
Yes, in adult-to-adult cases a right-lobe graft often exceeds half. The plan still leaves a safe remnant, usually above a third of total liver volume, and surgeons only proceed when imaging and lab work back that up.
What If The Recipient Is Much Larger?
Teams may add the middle hepatic vein to the right-lobe graft or steer to a donor with a larger liver. Some centers choose a left lobe for the donor and accept a longer recipient recovery when the math and anatomy stack up.
Does The Liver Grow Back After Donation?
Volume rebounds fast. Many donors reach near 80% within six weeks and continue to gain volume over the next few months. Lab values trail that curve and usually normalize with time, nutrition, and activity.
How To Read Percentages In A Consent Packet
The percentage in your paperwork is a best estimate. It comes from CT volumetry, then gets refined during surgery. Two numbers matter most: the graft-to-recipient weight ratio and the donor remnant. Ask your surgeon to show you the images and the math. Clear numbers help you weigh time off work, caregiving plans, and travel.
What Goes Into The Decision Meeting
- Imaging review. Surgeons study arteries, veins, and bile ducts to pick a safe cut line.
- Liver quality. Fat content on biopsy or MRI can change the plan or timeline.
- Recipient needs. Body size, MELD score, and portal pressures shape the graft pick.
- Donor goals. Work demands and home duties steer the choice toward a faster or slower recovery path when more than one option fits.
Practical Prep Tips For Potential Donors
- Line up a helper for the first two weeks at home. Plan rides, meals, and errands.
- Block time off with your employer. Many return to desk jobs in four to six weeks, but heavy labor needs a longer runway.
- Ask about laparoscopic options and pain-control plans, including nerve blocks.
- Build a walking routine and nutrition plan before surgery. Both speed recovery.
- Clarify follow-up dates and who to call after hours. Keep a simple log for meds, steps, and symptoms.
Key Takeaways On Percentages
Most adult recipients receive a right-sided graft near 55–70%. Smaller adults may receive a left lobe near 35–45%. Children often receive a left lateral segment near 15–25%. Donor safety hinges on leaving a healthy remnant at or above roughly one-third of total volume. Programs size the graft with imaging, body-weight math, and careful mapping so people do well.