Kasai Procedure: A Treatment for Biliary Atresia
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD | Last reviewed: October 7, 2026
Quick Answer: What is the Kasai procedure?
The Kasai procedure is surgery performed on infants, ideally before two months of age, to treat biliary atresia, a condition in which bile ducts are blocked or absent. Surgeons remove the damaged ducts and connect part of the small intestine directly to the liver so bile can drain [1]. It reduces jaundice, though many children later need a transplant [1].
What the research says
The earlier the Kasai procedure, the better the chance of keeping the child’s own liver. A systematic review and meta-analysis of 9 studies found that children who had the operation later reached liver transplantation significantly faster (HR 2.12, 95% CI 1.51–2.97), and that surgery at 30 days or younger carried a 1.22-times higher chance of native liver survival than surgery at 31 days or older (95% CI 1.13–1.31) (Hoshino et al., European Journal of Pediatrics, 2023) [2].
Surgery by about 90 days of age clears jaundice far more often than later surgery. A meta-analysis of 14 articles (3,276 infants) found that those operated on at 90 days or younger had higher odds of jaundice clearance (OR 3.05, 95% CI 2.23–4.17) and native liver survival (OR 1.72, 95% CI 1.37–2.15) than those older than 91 days; operating at 60 days or younger also improved native liver survival compared with 61–90 days (OR 1.41, 95% CI 1.18–1.68) (Yang et al., Frontiers in Surgery, 2022) [3].
Steroids after the Kasai procedure may improve bile flow, but they have not been shown to prevent cholangitis. A meta-analysis of 11 articles (1,032 patients) found that adjuvant steroid therapy improved jaundice clearance at 6 months (RR 1.35, 95% CI 1.18–1.55) and native liver survival at 24 months (RR 1.31, 95% CI 1.03–1.68), but did not significantly reduce postoperative cholangitis (RR 0.78, 95% CI 0.60–1.01, P = 0.058) (Yang et al., Frontiers in Pharmacology, 2022) [4].
Overview of the Kasai Procedure
The Kasai procedure is the primary surgical treatment for biliary atresia, a rare but serious liver condition in newborns. In infants with this condition, the bile ducts outside the liver are blocked, preventing bile from reaching the intestines [1]. This backup of bile causes significant damage to liver cells, leading to cirrhosis and, if left untreated, eventual liver failure [1].
The surgery is named after Dr. Morio Kasai, the surgeon who developed the technique. Its medical name, hepatoportoenterostomy [1], describes the core of the operation: creating a direct connection between the liver (hepato) and the small intestine (entero). By establishing this new pathway, the procedure attempts to bypass the blocked ducts and restore the essential flow of bile for digestion and waste removal.
Preparing for Surgery
Before the Kasai procedure begins, medical teams must confirm the diagnosis of biliary atresia through a diagnostic step called a cholangiogram [1]. This involves a small incision or laparoscopic tube to inject a special dye into the gallbladder, followed by X-rays to visualize the bile duct structure [1].
Preparation Step | Purpose and Details |
IV Fluids | Maintain hydration, stabilize sugar levels, and provide essential nutrients [1]. |
Antibiotics | Delivered intravenously to minimize the risk of post-surgical infection [1]. |
Blood Products | Red blood cells or platelets may be prepared in case a transfusion is needed [1]. |
Cholangiogram | A diagnostic X-ray procedure used to confirm the presence of blocked ducts [1]. |
Surgical Details and Hospital Recovery
During the operation, which typically lasts several hours [1], the surgeon removes the gallbladder and the abnormal, blocked bile ducts [1]. A specific section of the small intestine, known as the jejunum, is then surgically attached to the liver at the point where bile originates [1].
Post-operative care is intensive, with infants typically spending five to ten days in intensive care [1]. For the first few days, the baby will receive nutrition intravenously [1] to allow internal wounds to begin healing. As recovery progresses, feeding transitions from a nasogastric tube to oral formula or breastfeeding [1]. Surgeons monitor the infant closely for signs of successful bile drainage, such as the return of normal color to the baby’s stool [1].
Success Rates and Potential Risks
The success of the Kasai procedure is highly dependent on timing [2] [3]. Cleveland Clinic reports the best results when the surgery is done between six weeks and two months of age, with minimal liver damage and an experienced surgeon; under these conditions the procedure can reduce biliary atresia symptoms, especially jaundice, in more than 60% of infants [1].
However, the surgery is not without risks. The most common complication is cholangitis, an infection of the liver’s bile ducts. Additionally, the Kasai procedure is often considered a “bridge” rather than a permanent cure; approximately half of the infants who undergo the surgery will still require a liver transplant by the age of two [1].
Success Indicator | Description of Positive Outcome |
Bile Drainage | Return of normal (brown/yellow) color to the infant’s bowel movements [1]. |
Jaundice Relief | Clearing of the yellow tint in the skin and eyes for at least six months [1]. |
Liver Function | Improved results in blood tests measuring liver enzymes and bilirubin. |
Growth | Steady weight gain and development as the body absorbs nutrients properly. |
Recovery at Home
Full recovery from the Kasai procedure typically takes three to four months [1]. Parents play a crucial role during this period, managing long-term medications that include oral antibiotics to prevent infection and bile replacement medications to support digestion [1].
Hygiene is paramount during home recovery. Frequent hand washing and limiting the infant’s exposure to illness are essential [1], as their system is still healing. Healthcare providers strongly prefer breastfeeding during this time, as breast milk contains fats that are more easily absorbed by a recovering liver [1]. If breastfeeding is not possible, specialized formulas are often recommended [1].
Long-Term Outlook
While the Kasai procedure can provide years of healthy liver function for some children, it is important for families to stay informed about the possibility of future interventions. Regular follow-up appointments with pediatric hepatologists are necessary to monitor liver health and catch any signs of recurring blockages or liver disease early.
Conclusion
The Kasai procedure represents a vital opportunity for infants with biliary atresia to achieve better health and growth. By restoring bile flow, it addresses the immediate threat of liver damage and provides a pathway for improved quality of life. Although many children may eventually need a transplant, this surgery offers a critical window of time for growth and development.
Next Steps
If your infant has been diagnosed with biliary atresia, discuss the timing and specifics of the Kasai procedure with a pediatric surgical specialist immediately. Early intervention is the single most important factor in the surgery’s success. Ensure you have a support system in place, as the recovery process requires diligent care and frequent medical monitoring.
Frequently Asked Questions
What is the best age for a baby to have the Kasai procedure?
Cleveland Clinic reports the highest success when surgery is done between 6 weeks and 2 months of age. Research suggests that even earlier surgery, ideally within the first 30 days of life, is linked to better native liver survival, which is why a baby with prolonged jaundice should be evaluated promptly.
Will my baby still need a liver transplant?
About 50% of babies who have the Kasai procedure will eventually need a liver transplant by age 2.
How long does the surgery take?
The operation typically lasts several hours.
What are the signs that the surgery was successful?
Success is indicated by normal poop color, improved liver tests, and the absence of jaundice.
What is cholangitis?
Cholangitis is an infection of the liver’s bile ducts and is a common complication after the procedure.
How long is the hospital stay after surgery?
Most infants stay in the hospital for 5 to 10 days for recovery and monitoring.
Can I breastfeed my baby after the Kasai procedure?
Yes, breastfeeding is preferred because breast milk contains fats that are easily absorbed by the liver.
What medications will my baby need at home?
Babies usually need oral antibiotics for several months and bile replacement medications for several years.
What happens if the Kasai procedure doesn’t work?
If bile flow is not restored, the infant will likely be evaluated for a liver transplant.
How long is the total recovery period?
It generally takes about three to four months for an infant to fully recover from the surgery.
Why is a cholangiogram performed first?
A cholangiogram is used to confirm the diagnosis of biliary atresia before the major surgery begins.
What part of the intestine is used in the surgery?
A section of the small intestine called the jejunum is used to create the new bile path.
Is the Kasai procedure a permanent cure?
The Kasai procedure is often considered a treatment to slow the disease, but it may not be a permanent cure for all infants.
When should I call the doctor after going home?
Call immediately for a fever of 100.4°F (38°C) or higher, refusal to eat, pale or white poop, or if jaundice returns or worsens.
Does the surgery leave a large scar?
The surgeon makes an incision, usually below the ribs, which will leave a permanent scar as it heals.
How is my baby prepared for the Kasai procedure?
Biliary atresia is usually diagnosed within the first two months of life, and the surgery works best when done between 6 weeks and 2 months of age [1]. Babies operated on at 90 days or younger had better jaundice clearance and native-liver survival than those operated on later [3]. Before surgery your baby receives IV fluids for hydration, blood sugar and nutrients plus IV antibiotics to lower the infection risk, blood products such as red cells or platelets may be needed during the operation, and the surgeon confirms the diagnosis with a cholangiogram, an X-ray of the bile ducts after injecting dye, at the start of surgery [1].
Sources
Cleveland Clinic. Kasai Procedure. Cleveland Clinic. Last updated October 16, 2024. https://my.clevelandclinic.org/health/procedures/kasai-procedure
Hoshino E, Muto Y, Sakai K, et al. Age at surgery and native liver survival in biliary atresia: a systematic review and meta-analysis. Eur J Pediatr. 2023;182(6):2693-2704. PMID: 36997770. DOI: 10.1007/s00431-023-04925-1
Yang C, Ke M, Zhou Y, et al. Impact of early Kasai portoenterostomy on short-term outcomes of biliary atresia: a systematic review and meta-analysis. Front Surg. 2022;9:924506. PMID: 36117834. DOI: 10.3389/fsurg.2022.924506
Yang CZ, Zhou Y, Ke M, et al. Effects of postoperative adjuvant steroid therapy on the outcomes of biliary atresia: a systematic review and updated meta-analysis. Front Pharmacol. 2022;13:956093. PMID: 36188593. DOI: 10.3389/fphar.2022.956093
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Medical disclaimer
This content is for informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or surgical procedure.
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