Doppler ultrasonographic evaluation of ductus venosus blood flow in 55 canine fetuses

Abstract

Purpose The ductus venosus (DV) blood flow has been studied in fetal lambs and in humans. This study aims to describe the velocities, the Doppler indices and the morphological patterns of the venous blood flow in the DV of canine fetuses during physiological pregnancy. Methods The DV of 55 canine fetuses has been evaluated and the waveforms described using B-mode, color and pulsed-wave Doppler ultrasound technology. Results We found 48 diphasic waves and 7 threephasic waves. No monophasic waveform was found. Six of seven threephasic waveforms belonged to litters in which perinatal mortality occurred. The peak velocity during ventricular systole S (cm/s), the peak velocity during the ventricular diastole D (cm/s), the velocity during atrial contraction aV (cm/s), the S/D index, the pulsatility index (PI) and the resistance index were measured. Conclusions All Doppler indices and velocities were significantly correlated with each other (p \ 0.05). The number of newborn puppies and the age of bitches were not related to DV vascular indices or flow rate (p [ 0.05). Gestational age was proportional to the PI (p \ 0.02). Doppler ultrasonography allows the assessment of DV blood flow in canine fetuses during pregnancy.Keywords Sonography Á Ductus venosus Á Canine fetuses SOMMARIO Scopo Il flusso del dotto venoso (DV) è stato studiato in feti di agnelli e negli esseri umani. Questo studio intende descrivere le velocità, gli indici Doppler e i modelli morfologici nel DV di feti di cane, durante la gravidanza fisiologica. Metodi E' stato valutato Il DV di 55 feti di cane e descritte le forme d'onda utilizzando B-mode, Color Doppler e Doppler pulsato. Risultati Abbiamo rilevato 48 onde difasiche e 7 onde trifasiche. Nessuna forma monofasica è stato rilevata. Sei delle sette forme d'onda trifasica appartenevano a cucciolate in cui si è verificata mortalità perinatale. Sono stati misurati Il picco di velocità durante la sistole ventricolari S (cm/s), la velocità di picco durante la diastole ventricolare D (cm/s), la velocità durante la contrazione atriale aV (cm/ s), l'indice S/D (S/D), l'indice di pulsatilità (PI) e l'indice di resistenza (RI). Conclusioni Tutti gli indici Doppler e le velocità erano significativamente correlati tra loro (P \ 0.05). Il numero di cuccioli appena nati e l'età delle femmine non erano correlati con gli indici vascolari del DV o con la portata (p [ 0,05). L'età gestazionale era proporzionale alla PI (p \ 0,02). Il Doppler permette di valutare il flusso sanguigno del DV nei feti di cane durante la gravidanza.

Colour Flow Mapping examination: An useful screening test for the early diagnosis of ductus venosus patency in canine newborns

“…In humans, the presence of a triphasic waveform in the DV (reverse a‐wave which corresponds to a deflection during atrial contraction) is considered a strong predictor of neonatal mortality independently of gestational age (Turan et al, ). Some authors reported ultrasonographic evaluation of the blood flow of the DV in dogs (Barella, Faverzani, Faustini, Groppetti, & Pecile, ). Recently it was reported that the presence of a reverse DV a‐wave (triphasic waveform pattern) suggests an accurate pregnancy monitoring and perinatal assistance for high‐risk neonatal mortality in dogs, too (Barella, Faverzani, Faustini, Groppetti, & Pecile, ).…”

Neonatal mortality in dogs: Prognostic value of Doppler ductus venosus waveform evaluation - Preliminary results

“…The DV is a small trumpet-shaped vessel of a few millimeters length and width, originating from the umbilical vein and reaching the caudal vena cava near the confluence of the hepatic veins, gradually reducing its diameter. Several studies reported ultrasonographic evaluation of DV blood flow in fetal lambs [ 3 , 4 ] and in dogs [ 5 ]. According to human literature the ultrasonographic Doppler waveforms of DV are classified as monophasic, diphasic or triphasic (dDVw or tDVw) [ 6 ], while only two different types of waveforms have been described in canine fetuses (diphasic or triphasic) [ 5 ].…”