Outcomes associated with fetal hepatobiliary cysts: systematic review and meta-analysis

Objective To explore the outcomes associated with fetal hepatobiliary cysts. Methods MEDLINE and EMBASE were searched for studies reporting on outcomes of fetal hepatobiliary cysts. Outcomes observed were resolution/reduction and increase in cyst size, associated congenital anomalies of the biliary tract and liver, abnormal postnatal liver function tests, clinical symptoms, need for surgery, postsurgical complications and predictive accuracy of prenatal ultrasound in identifying correctly hepatobiliary cysts. Meta-analysis of proportions was used to analyze the data. Results The search identified 1498 articles, and 22 studies (252 fetuses) were included in the systematic review. For fetal hepatic cysts, resolution or reduction in cyst size either pre- or postnatally occurred in 59.3% (95% CI, 30.9-84.7%) of cases, while an increase in cyst size occurred in 8.7% (95% CI, 1.1-22.4%). No case of hepatic cyst had associated malformations of the biliary tract at birth. Clinical symptoms occurred in 14.8% (95% CI, 6.3-26.1%) of cases and, in 5.4% (95% CI, 0.9-13.6%), they were related to the presence of bile obstruction due to compression of the cyst on the biliary tract. No case of hepatic cyst had abnormal liver function at birth. For fetal biliary cysts, resolution or reduction in cyst size occurred in 8.7% (95% CI, 2.7-17.5%) of cases and an increase in size occurred in 34.4% (95% CI, 20.5-49.8%). Congenital anomalies of the biliary tract and liver, such as fibrosis, occurred in 21.5% (95% CI, 10.2-35.6%) and 17.4% (95% CI, 5.4-34.4%) of cases, respectively. 57.3% (95% CI, 33.9-79.0%) of cases showed impairment in liver function after birth, while 55.0% (95% CI, 37.5-71.9%) showed clinical symptoms, mainly due to bile obstruction (47.9% (95% CI, 29.4-66.7%)). Postsurgical complications occurred in 10.9% (95% CI, 3.7-21.3%) of operated cases. Risk assessment according to different cut-offs of cyst size could not be performed in view of the very small number of included studies. Conclusions Fetal hepatic cysts are benign, with a low likelihood of associated anomalies of the hepatobiliary tract, abnormal liver function or clinical symptoms. Congenital biliary cysts are associated with a high rate of progression, abnormal liver function after birth and clinical symptoms.