Purpose or Case Report: Sinusoidal obstruction syndrome (SOS) is a potentially fatal disease affecting children following bone marrow transplantation (BMT). SOS diagnosis is clinical because traditional ultrasound has poor sensitivity and specificity with portal vein flow reversal occurring well after the disease is clinically evident. Ultrasound elastography is a newer technology that measures liver stiffness, which should increase in SOS due to passive hepatic congestion. Our hypothesis is that quantitative shear wave ultrasound elastography will be more accurate in detecting this disease compared with conventional ultrasound parameters.
Methods & Materials: This is a single site prospective cohort study evaluating ultrasound elastography in BMT patients from December 2015 to October 2016. We included subjects up to age 21 undergoing allogenic or autologous myeloblative stem cell transplant and excluded those undergoing reduced intensity conditioning regimen for stem cell transplant or haplo identical transplant. SOS was defined using the modified Seattle criteria. Subjects had abdominal Doppler ultrasounds with shear wave elastography at two time points: 1) one-week prior to conditioning regimen, 2) Day +14 of BMT. Other standard of care ultrasounds with elastography were included. Ultrasounds were performed on a GE Logiq E9 with a curved 1-6 MHz transducer. For elastography, at least ten measurements were obtained in the right hepatic lobe at the mid clavicular line just below the ribs approximately three centimeters below the capsule. Patients were divided into two groups those developed SOS (group I) and those who did not (group II). Two tailed t-tests were used to compare the two groups.
Results: A total of 39 ultrasound examinations were performed on 12 patients with three subjects developing SOS. Gender was split evenly with an average age of 10 years (1-20 years). The change in group I’s shear wave velocities were 0.44, 0.79 and 2.88 m/s. The range of group II’s changes were -0.05 to 0.045 m/s (Figure 1). The groups were not were statistically significantly different (Table I: p=0.20).
Conclusions: Patients who develop SOS have increased liver stiffness as measured by ultrasound elastography compared to patients who do not develop SOS. This difference is clinically significant but not statistically significant, likely due to small patient numbers.