Prenatal sonographic characteristics and postnatal outcomes of umbilical-portal-systemic venous shunts under the new in-utero classification: A retrospective study

Abstract

An in-utero re-classification of umbilical-portal-systemic venous shunt (UPSVS) has recently been proposed. We retrospectively reviewed the sonograms of a large cohort of fetuses, identified and analyzed UPSVS cases, and presented the prenatal sonographic characteristics, birth outcomes, and follow-up results following the new classification system.Sonograms and clinical data of all participants who visited our departments from April 2016 to July 2018 were retrospectively reviewed. Identified cases of UPSVS were analyzed according to the new classification: Type I: umbilical-systemic shunt (USS); Type II: ductus venosus-systemic shunt (DVSS); Type IIIa: intrahepatic portal-systemic shunt (IHPSS) and Type IIIb: extrahepatic portal-systemic shunt (EHPSS). Postnatal follow-ups ranged from 3 months to 1 year.A total of 10 UPSVS cases were identified in 61,082 fetuses: 4 with Type I, 3 with Type II and 3 with Type IIIa. All 4 cases of USS had complete agenesis of the portal venous system, and had the umbilical vein drained into the inferior vena cava. Two USS cases also had trisomy 21. Pregnancy was terminated in all cases with a Type I shunt. Two fetuses with DVSS had normal portal venous system and were born full term. The pregnancy of 1 DVSS case was terminated due to the detection of trisomy 21. Three cases were IHPSS with full-term birth. One had chromosomal abnormality and 1 had surgery to repair the shunt 12-days post birth. In the 2 cases that did not receive repair surgery, sonographic examination revealed the portal-hepatic venous shunt was not closed at the 6-month follow-up period. However, the 1 case that had repair surgery appeared healthy at the 3-month follow-up period.UPSVS is extremely rare. Type I shunts have the poorest prognosis, and the presence of the intrahepatic portal venous system is key to live birth in UPSVS regardless of types. Chromosomal abnormalities and other organ anomalies can occur in any types of UPSVS. Therefore, karyotyping and examination of other organs should be performed once UPSVS is detected.

Figure 1

A representative sonogram of case 2. Shown here is a sagittal scan of the Type I shunt. The UV was seen to connect the IVC, and triphasic waveforms at the site of shunt were detected (inserted at the right-upper corner). Arrow indicates the shunt site. IVC = inferior vena cava, SP = spine, UV = umbilical vein.

Figure 2

A representative sonogram of case 5. Shown here is a transverse scan to demonstrate the Type 2 shunt. The structure of UV, portal veins (LPV and RPV) and the DV (arrow) appeared intact with the DV draining into the hepatic segment of the IVC. DV type velocity waveforms were detected at the shunt site (inserted at the right-upper corner). AO = aorta, IVC = inferior vena cava, LPV = left portal vein, RPV = right portal vein, UV = umbilical vein.

Figure 3

A representative sonogram of case 8. A transverse scan shows a shunt (arrow) between the LPVi and LHV. LHV was enlarged and triphasic waveforms were detected at the shunt site (inserted at the right-upper corner). AO = aorta, LHV = the left hepatic vein, LPVi = inferior branch of the left portal vein, LPVs = superior branch of the left portal vein, SP = spine.

Figure 4

A representative sonogram of case 9. A transverse scan shows multiple shunts (arrows) between the left portal vein and the left hepatic vein/middle hepatic vein. Triphasic waveforms were detected at the shunt site (inserted at the right-upper corner). AO = aorta, LHV = the left hepatic vein, LPVi = inferior branch of the left portal vein, MHV = middle hepatic vein, UV = umbilical vein.