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PubMed This is a summary of 20 peer-reviewed journal articles Updated
Pediatric Surgery · Biliary Atresia

The Kasai Procedure: The Standard of Care Surgery

At a Glance

The Kasai procedure is the primary surgery for infants with biliary atresia. It restores bile flow by connecting the intestine directly to the liver. For the best chance of saving the baby's natural liver, the surgery should ideally be performed before the baby is 45 days old.

The Kasai portoenterostomy (KPE) is the primary surgical treatment for infants with biliary atresia. While it is a major operation, it is a well-established procedure that has transformed the outlook for children born with this condition, allowing many to live for years—or even decades—with their original liver [1][2].

What Happens During the Surgery?

In plain language, the goal of the Kasai procedure is to create a new “drainage system” for the liver. You will often see the term Roux-en-Y portoenterostomy in your surgical notes, which is the medical name for this technique. Because the bile ducts outside the liver are blocked or destroyed, the surgeon:

  1. Removes the damaged ducts: The scarred and blocked extrahepatic (outside the liver) ducts are carefully removed [3].
  2. Connects the intestine: The surgeon takes a loop of the baby’s small intestine and attaches it directly to the porta hepatis—the spot on the bottom of the liver where bile should drain out [4].
  3. Restores bile flow: By sewing the intestine directly to the liver surface, the microscopic ducts still inside the liver can drain bile directly into the digestive tract, preventing further liver damage [1].

The ‘Golden Period’ for Surgery

Timing is the most critical factor in the success of the Kasai procedure. Biliary atresia is a progressive disease, meaning the liver scars more every day that bile remains trapped [5].

  • Under 30–45 Days: This is often considered the “Golden Period.” Infants who undergo surgery before 45 days of life have the highest rates of jaundice clearance and the best long-term native liver survival (living with their own liver) [6][7].
  • 45–60 Days: Success is still very likely, but the risk of established liver scarring (fibrosis) increases [8].
  • Over 90 Days: While still performed as a “bridge” to transplant, the success rate for clearing jaundice drops significantly in babies older than 3 months [9][10].

The Immediate Hospital Recovery

Parents should prepare for a challenging immediate post-operative period. Your baby will likely spend 1 to 2 weeks in the hospital, initially in the Pediatric Intensive Care Unit (PICU) or a specialized surgical ward [1].

  • What to expect visually: When you first see your baby after surgery, they will likely have several tubes and lines. This often includes an IV for fluids and pain medication, a tube in their nose to keep their stomach empty, and sometimes a drain near their incision. This is a normal part of the healing process.
  • Jaundice fading takes time: Even if the surgery is highly successful, the physical yellowing of the skin and eyes can take weeks or months to fade fully. Do not panic if your baby still looks yellow a week after surgery. Blood tests are the only true measure to watch [11].

Not a Cure, but a Vital Bridge

It is important to understand that for most children, the Kasai procedure is not a permanent cure, but a bridge [12].

  • Goal 1: Clear Jaundice. Success is defined by the baby’s skin and eyes returning to a normal color within 3 to 6 months [11].
  • Goal 2: Save the Native Liver. About 30% to 50% of children will live with their own liver for at least 10 years after a successful Kasai [13][14].
  • Goal 3: Delay Transplant. Even if a child eventually needs a liver transplant, the Kasai procedure allows them to grow larger and stronger first. A prior Kasai does not make a future transplant more difficult or less successful [15][16].

Factors That Influence Success

Beyond the baby’s age, two other factors play a major role:

  • Center Experience: Research shows that outcomes are significantly better when the surgery is performed at “high-volume” centers where the surgical team performs the Kasai procedure frequently [17][18]. Don’t be afraid to ask your surgeon how many Kasai procedures their center performs annually; a volume of >5 cases per year is generally preferred in pediatric hepatology.
  • Preventing Infections: After surgery, the main risk is cholangitis—an infection of the new bile drainage system. Your team will likely use preventive antibiotics to protect the liver during recovery [19][20].

Common questions in this guide

What happens during the Kasai procedure?
During the Kasai procedure, a surgeon removes the blocked bile ducts outside the liver. They then attach a loop of the baby's small intestine directly to the liver to allow bile to drain into the digestive tract.
When is the best time to perform the Kasai procedure?
The highest success rates occur during the 'Golden Period,' which is when the infant is under 30 to 45 days old. Performing the surgery early helps prevent irreversible liver scarring and increases the chances of the baby living with their own liver.
Is the Kasai procedure a permanent cure for biliary atresia?
For most children, the Kasai procedure is not a permanent cure but a vital bridge to delay the need for a liver transplant. A successful surgery clears jaundice and allows the child to grow stronger, with many children keeping their native liver for a decade or more.
How long does it take for jaundice to go away after Kasai surgery?
The physical yellowing of the skin and eyes can take weeks or months to fully fade after a successful Kasai procedure. The medical team will use blood tests to accurately monitor if the liver is clearing bile properly during recovery.
What are the risks or complications after a Kasai procedure?
The most common immediate risk after surgery is cholangitis, which is an infection of the new bile drainage system. Medical teams typically prescribe preventive antibiotics to protect the liver during the recovery period.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.What is your individual and hospital success rate for the Kasai procedure in terms of jaundice clearance?
  2. 2.How many Kasai procedures does this center perform per year, and do you consider this a high-volume center?
  3. 3.How many days old will my child be on the day of the surgery?
  4. 4.What is your protocol for preventing and treating post-operative cholangitis (infection)?
  5. 5.If the Kasai procedure is not successful, at what point do we begin discussing the timeline for a liver transplant?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (20)
  1. 1

    [Kasai-hepatoportoenterostomy for the treatment of biliary atresia - What is important?]

    Madadi-Sanjani O, Herden U, Uecker M

    Chirurgie (Heidelberg, Germany) 2025; (96(6)):474-481 doi:10.1007/s00104-025-02259-2.

    PMID: 40016476
  2. 2

    Morio Kasai Corrects the Uncorrectable: Hepatic Portoenterostomy for Biliary Atresia.

    Nakayama DK

    Journal of pediatric surgery 2024; (59(12)):161765 doi:10.1016/j.jpedsurg.2024.161765.

    PMID: 39277499
  3. 3

    Findings in percutaneous cholangiography in two cases of Type III cystic biliary atresia (with ultrasound correlation).

    Parra D, Fecteau A, Daneman A

    BJR case reports 2016; (2(2)):20150377 doi:10.1259/bjrcr.20150377.

    PMID: 30363637
  4. 4

    The effects of Kasai procedure on living donor liver transplantation for children with biliary atresia.

    Li S, Ma N, Meng X, et al.

    Journal of pediatric surgery 2019; (54(7)):1436-1439 doi:10.1016/j.jpedsurg.2018.07.022.

    PMID: 30243738
  5. 5

    Infants with extrahepatic biliary atresia: Effect of follow-up on the survival rate at Ege University Medical School transplantation center.

    Karakoyun M, Baran M, Turan C, et al.

    The Turkish journal of gastroenterology : the official journal of Turkish Society of Gastroenterology 2017; (28(4)):298-302 doi:10.5152/tjg.2017.16622.

    PMID: 28699603
  6. 6

    Age at surgery and native liver survival in biliary atresia: a systematic review and meta-analysis.

    Hoshino E, Muto Y, Sakai K, et al.

    European journal of pediatrics 2023; (182(6)):2693-2704 doi:10.1007/s00431-023-04925-1.

    PMID: 36997770
  7. 7

    Steroids after the Kasai procedure for biliary atresia: the effect of age at Kasai portoenterostomy.

    Tyraskis A, Davenport M

    Pediatric surgery international 2016; (32(3)):193-200 doi:10.1007/s00383-015-3836-3.

    PMID: 26590818
  8. 8

    Postoperative steroid therapy for biliary atresia: Systematic review and meta-analysis.

    Chen Y, Nah SA, Chiang L, et al.

    Journal of pediatric surgery 2015; (50(9)):1590-4.

    PMID: 26143225
  9. 9

    Kasai Procedure in Patients Older Than 90 Days: Worth a Cut.

    Uecker M, Kuebler JF, Schukfeh N, et al.

    European journal of pediatric surgery : official journal of Austrian Association of Pediatric Surgery ... [et al] = Zeitschrift fur Kinderchirurgie 2022; (32(1)):80-84 doi:10.1055/s-0041-1740556.

    PMID: 34918313
  10. 10

    Impact of early Kasai portoenterostomy on short-term outcomes of biliary atresia: A systematic review and meta-analysis.

    Yang C, Ke M, Zhou Y, et al.

    Frontiers in surgery 2022; (9()):924506 doi:10.3389/fsurg.2022.924506.

    PMID: 36117834
  11. 11

    Predictors of Successful Kasai Portoenterostomy and Survival with Native Liver at 2 Years in Infants with Biliary Atresia.

    Kumar R, Lal BB, Sood V, et al.

    Journal of clinical and experimental hepatology 2019; (9(4)):453-459 doi:10.1016/j.jceh.2018.09.008.

    PMID: 31516261
  12. 12

    Optimizing Post-Kasai Management in Biliary Atresia: Balancing Native Liver Survival and Transplant Timing.

    Madadi-Sanjani O, Uecker M, Thomas G, et al.

    European journal of pediatric surgery : official journal of Austrian Association of Pediatric Surgery ... [et al] = Zeitschrift fur Kinderchirurgie 2025; (35(4)):261-268 doi:10.1055/a-2507-8270.

    PMID: 39719262
  13. 13

    Life long follow up and management strategies of patients living with native livers after Kasai portoenterostomy.

    Chung PHY, Chan EKW, Yeung F, et al.

    Scientific reports 2021; (11(1)):11207 doi:10.1038/s41598-021-90860-w.

    PMID: 34045634
  14. 14

    Long-term Results and Quality of Life Assessment in Biliary Atresia Patients: A 35-Year Experience in a Tertiary Hospital.

    Wong CWY, Chung PHY, Tam PKH, Wong KKY

    Journal of pediatric gastroenterology and nutrition 2018; (66(4)):570-574 doi:10.1097/MPG.0000000000001854.

    PMID: 29216021
  15. 15

    Primary vs. salvage liver transplantation for biliary atresia: A retrospective cohort study.

    Yoeli D, Choudhury RA, Sundaram SS, et al.

    Journal of pediatric surgery 2022; (57(10)):407-413 doi:10.1016/j.jpedsurg.2021.12.027.

    PMID: 35065808
  16. 16

    Comparative outcomes of open and laparoscopic Kasai portoenterostomy for biliary Atresia patients progressing to liver transplantation: A Real-World cohort study.

    Zhang Y, Qiu Y, Wang S, et al.

    Surgery today 2026; (56(6)):1021-1032 doi:10.1007/s00595-025-03210-y.

    PMID: 41384976
  17. 17

    Association between Kasai portoenterostomy at low caseload centres and transplant complications in children with biliary atresia.

    Betalli P, Cheli M, Colusso MM, et al.

    Journal of pediatric surgery 2022; (57(9)):223-228 doi:10.1016/j.jpedsurg.2021.12.030.

    PMID: 35063251
  18. 18

    The Outcome of a Centralization Program in Biliary Atresia: Twenty Years and Beyond.

    Davenport M, Makin E, Ong EG, et al.

    Annals of surgery 2025; (281(4)):608-614 doi:10.1097/SLA.0000000000006273.

    PMID: 38506040
  19. 19

    Effect of medium chain triglycerides enriched formula on growth of biliary atresia patients after Kasai portoenterostomy.

    El-Koofy N, Mahmoud E, El Mougy F, et al.

    Arab journal of gastroenterology : the official publication of the Pan-Arab Association of Gastroenterology 2024; (25(2)):188-193 doi:10.1016/j.ajg.2024.01.015.

    PMID: 38378358
  20. 20

    Primary antibiotic prophylaxis in biliary atresia did not demonstrate decreased infection rate: Multi-centre retrospective study.

    Brody Y, Slae M, Amir AZ, et al.

    Acta paediatrica (Oslo, Norway : 1992) 2025; (114(3)):654-659 doi:10.1111/apa.17493.

    PMID: 39528247

This page provides educational information about the Kasai procedure for biliary atresia. It does not replace professional medical advice from your child's pediatric surgeon or hepatologist.

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