Time‐interval analysis of ductus venosus flow velocity waveforms in twin‐to‐twin transfusion syndrome treated with laser surgery

Abstract

Objectives To investigate time-interval variables of ductus venosus (DV) flow velocity waveforms (FVWs) in twin-to-twin transfusion syndrome (TTTS), comparingthe results with reference ranges from normal singleton fetuses. The impact of laser surgery and the effect of prognostic factors were also evaluated. S and D, respectively). For each variable, Z-scores were calculated with respect to previously reported normal reference ranges. Methods In 107 TTTS cases, DV-FVWs of both recipients and donors were recorded 1 day before and 2 days after laser therapy. Time intervals for systolic (S) and early diastolic (D) peaks were analyzed retrospectively with regard to acceleration time (acc-S and acc-D for S and D, respectively) and deceleration time (dec-S and dec-D for Results Z-scores for all variables showed statistically significant differences from those observed previously in normal fetuses, with the exception of dec-S of donors. The most striking differences were observed in longer dec-S of recipients (P < 0.001) and longer dec-D of donors (P < 0.001). Laser therapy showed significant impact on dec-S and acc-D in recipients and on all variables in donors.Regarding the short-term prognosis, acc-S and dec-S showed significant differences for the prediction of intrauterine fetal demise in donors (P = 0.009 and P = 0.011, respectively). Conclusion

Time Interval Measurements of the Ductus Venosus During the Early Second Trimester of Pregnancy: Reference Ranges and Clinical Application

“…The awareness of ductus venosus time intervals can also be of benefit in terms of monitoring the response to treatment. Tachibana et al reported significant divergences of time interval measurements after fetoscopic laser coagulation of anastomotic vessels; a decreased systolic deceleration time with a simultaneously increased diastolic acceleration time in the recipients may reflect an improvement in cardiac function …”

“…Our study found alterations of the ductus venosus time interval variables even in the early stages of twin‐twin transfusion syndrome. The shortening acceleration phase of ventricular contraction in the donor twins was in accordance with a previous report . Another study suggested that the reduction of the systolic time was caused by decreased ejection forces and cardiac output from hypovolemia .…”

“…Ductus venosus profiles are useful in the assessment of the fetal hemodynamic status. Pregnancies complicated by fetal cardiac anomalies, especially cases of right heart obstruction, monochorionic twin pregnancy with unbalanced blood flow between the fetuses, and placental dysfunction, are associated with abnormal ductus venosus indices.…”

Fetal cardiovascular hemodynamics in twin–twin transfusion syndrome

“…Both preload and afterload are altered by SFLP, demonstrated by a significant decrease in DV pulsatility index and normalization of time intervals with lengthening of filling times, reflecting improved diastolic heart function in the recipient . This is also shown in a significant improvement of left‐ and right‐ventricular Tei index and an increase in the shortening fraction after SFLP .…”

Changes in ductus venosus flow profile in twin–twin transfusion syndrome: role in risk stratification

“…Previous studies have shown shortened filling times in the recipients' DV in twin–twin transfusion syndrome (TTTS). Attempts to classify DV velocity patterns have been undertaken in fetuses with altered PIV, including twins complicated by TTTS, but have not shown a specific velocity pattern.…”