Predicting the Impact of Degree and Duration of Uterine Torsion on Uterine Blood Supply in Cattle using Doppler Ultrasonography

The aim of study was doppler ultrasonography-aided assessment of uterine blood flow in relation to duration and degree of uterine torsion in cattle. Fourteen dairy cattle with uterine torsion were detorted and fetal delivery was completed after detorsion. Six live and eight dead calves were delivered by cattle having torsion from lesser and prolonged duration, respectively. Whereas the dams of majority of live (n = 4/6) or dead (n = 5/8) fetus had uterine torsion ≤180° or >180°, respectively. Doppler ultrasonography of middle uterine artery ipsilateral (IpsiUA) and contralateral (ContUA) to the side of torsion was carried out before uterine detorsion for doppler indices viz. blood flow volume (BFV), time-average peak velocity (TAP), resistive index (RI) and pulsatility index (PI). With increase in degree and duration of torsion, BFV in both IpsiUA and ContUA reduced significantly (p<0.05) but TAP decreases only with increase in duration of torsion. In ipsilateral uterine artery PI (PI-IpsiUA) increased with an increase in duration of torsion (p<0.05). The presence of Pre-diastolic notch in IpsiUA and ContraUA validates the hindrance in blood flow through the vessel and absence of diastole in higher degree and/or duration of uterine torsion defined the severity of torsion which further relates to fetal viability. In conclusion, assessing the blood flow parameters of middle uterine artery in relation to degree and duration of uterine torsion can serve as useful prognostic indicator. The cattle having lesser degree of uterine torsion could have more chances of fetal survival due to lesser alterations in blood flow.