Assessment of hepatic veno-occlusive disease/sinusoidal obstruction syndrome using different scanning approaches for the ultrasonographic evaluation of portal vein blood flow and hepatic artery resistive index in hematopoietic stem cell transplant recipients

Purpose Sinusoidal obstruction syndrome (SOS) is a fatal complication of hematopoietic stem cell transplantation (HSCT). Previously, we established a scoring system (Hokkaido ultrasound-based scoring system-10; HokUS-10) comprising 10 ultrasound parameters for SOS diagnosis. In HokUS-10, the portal vein time-averaged flow velocity (PV TAV) and hepatic artery resistive index (HA RI) are measured using subcostal scanning. However, measurement errors and delineation difficulties occur. Therefore, we aimed to prospectively evaluate PV TAV and HA RI measurements obtained via intercostal scanning as an alternative method to subcostal scanning and determine their cutoff values. Methods HokUS-10 was administered before and after HSCT. PV TAV and HA RI were measured on subcostal and right intercostal scans. Results We performed 366 scans on 74 patients. The median value (range) of PV TAV in the main and right portal veins was 15.0 cm/s (2.2–49.6 cm/s) and 10.5 cm/s (1.6–22.0 cm/s), respectively. A low correlation was observed between the two values (r = 0.39, p < 0.01). The highest diagnostic value of the right portal vein was less than 8.0 cm/s. The median value (range) of HA RI in the proper and right hepatic arteries was 0.72 (0.52–1.00) and 0.70 (0.51–1.00), respectively. A strong correlation was observed between the two values (r = 0.65, p < 0.01). The highest diagnostic value of the right HA RI was 0.72 or higher. Conclusion Quantitative measurement of PV TAV and HA RI using intercostal scanning can be appropriately performed as an alternative method to using subcostal scanning.