Rare biliary atresia variant linked to better clinical outcomes: China study
Infants with subtype tend to have surgery sooner than those with other forms
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Infants with cystic biliary atresia (CBA) tend to undergo standard Kasai surgery earlier than those with other forms of biliary atresia, and generally have better outcomes following surgery, according to a study in China.
“The overall prognosis for CBA is superior to that of non-CBA,” researchers wrote. “These findings provide valuable clinical guidance for the individualized treatment and follow-up management strategies for CBA.”
The study, “A prognostic analysis of cystic and non-cystic biliary atresia,” was published in Surgical Endoscopy.
Cystic biliary atresia marked by presence of fluid-filled structures
The bile ducts are a series of tubes that normally carry bile, a digestive substance, from the liver to the intestines. Biliary atresia is a condition in which these ducts are missing or blocked from birth, so bile cannot flow properly.
The first-line treatment for biliary atresia, known as the Kasai portoenterostomy, is a surgical procedure that creates an alternate bile route into the small intestine, bypassing the blocked ducts and restoring bile flow.
Biliary atresia is classified into three types according to the affected bile ducts. Type III, in which all the main bile ducts (including those within the liver) are blocked or absent, is the most common form, accounting for about 90% of cases.
Cystic biliary atresia is a specific subtype of type III reported in 5% to 10% of biliary atresia patients. It is marked by the presence of cystic (fluid-filled) structures within affected bile ducts outside the liver.
“With the advancement of prenatal ultrasound technology, an increasing number of children diagnosed with CBA can now be identified during the early stages of the postnatal period, allowing them to undergo Kasai portoenterostomy (KPE) at an earlier age,” the researchers wrote.
Many CBA studies to date are limited by small numbers of patients and “insufficient medium- and long-term follow-up data, leading to inconsistent conclusions,” the researchers added.
Infants with CBA were significantly younger when they underwent surgery
To learn more about how outcomes in CBA compare against those of other forms of biliary atresia, a team of researchers in China analyzed outcomes from nearly 200 patients who underwent the Kasai procedure at a single Chinese hospital between 2016 and 2020.
Specifically, there were 22 children with CBA and 174 with non-CBA forms of biliary atresia. Both groups were followed for up to five years after surgery, “with two patients lost to follow-up in the CBA group and three in the non-CBA group,” the researchers wrote.
Results showed that infants with CBA were significantly younger when they underwent Kasai surgery than those with non-CBA (median age of about 7 weeks vs. 9 weeks).
Children with CBA also generally had better outcomes following surgery. Resolution of jaundice — yellowing of the eyes and skin, a common symptom of liver damage — occurred in 90% of infants with CBA and 69% of those in the non-CBA group by six months after surgery. This difference was statistically significant.
At three years post-surgery, the jaundice resolution was 70% in the CBA group and 40.9% in the non-CBA group. These rates dropped to 55% and 30.4%, respectively, at five years after surgery. Again, group differences reached statistical significance.
Infants in the CBA group were also significantly less likely to develop cholangitis (bile duct inflammation) after Kasai surgery (60% vs. 84.8%). They also had significantly lower liver stiffness values at each follow-up time point, indicating less liver scarring or fibrosis.
The results indicated that children with CBA had more favorable outcomes than those with non-CBA in several prognostic indicators.
At five years after surgery, nearly two-thirds (67.87%) of children in the CBA group were still alive without needing a liver transplant, compared with less than half (40.10%) of those in the non-CBA group.
“The results indicated that children with CBA had more favorable outcomes than those with non-CBA in several prognostic indicators,” the researchers wrote.
The team noted that the better outcomes observed in the CBA group are likely driven, at least in part, by the fact that these infants generally underwent surgery earlier. An earlier age at surgery is typically associated with better outcomes for infants with biliary atresia.
The fact that CBA causes fluid-filled structures that are often easily visible on medical imaging tests may help explain this discrepancy, as it could allow faster diagnosis and facilitate earlier surgery.
Disease-intrinsic factors may also be at play, however, and the researchers stressed the need for more studies into how CBA compares with non-CBA forms of biliary atresia.
“In the future, multicenter [studies following patients over time] should be conducted to further validate the long-term prognostic advantages of CBA,” the researchers wrote. “At the same time, an in-depth analysis of the differences between CBA and non-CBA [disease features] should be carried out.”
