Doppler ultrasonographic assessment of uterine arteries during normal canine puerperium

A descriptive angiographic study of the uterine arteries during pregnancy, the postpartum period and CEH/pyometra in bitches

The aim of this descriptive study was to monitor the changes in uterine arteries during pregnancy, postpartum period and pyometra in bitches using angiography. Fifteen uteri of mixed breed bitches on days 24, 30, 33, 40, 43, 47, 50 and 56 of pregnancy and weeks 1, 2, 3, 4 and 7-8 of postpartum and two CEH/pyometra bitches were examined after ovariohysterectomy. The results showed that with the onset of normal pregnancy and in about 30 ± 1 days of gestation, anastomoses begin to form between the left and right middle uterine arteries, developing during the next days and continuing until 4 weeks postpartum. On 4th week after parturition, when physiologic changes occur and the uterus returns to non-pregnant conditions, these anastomoses begin to degenerate, and they completely disappear approximately on the 7th-8th week after parturition. Similarly, in CEH/pyometra bitches, anastomoses were formed between left and right median uterine arteries. These findings can be considered as a part of the physiological changes of the uterus and its vessels during pregnancy and postpartum periods and could affect the results and interpretation of relevant findings.

Contrast-Enhanced Ultrasound in Cystic Endometrial Hyperplasia-Pyometra Complex in the Bitch: A Preliminary Study

Simple Summary

In canine cystic endometrial hyperplasia–pyometra (CEH) syndrome, toxic factors and endometrial inflammatory reactions are responsible of increased blood flow and lower vascular resistance in uterine arteries. Color Doppler ultrasound is regarded as an adjunctive tool for quantitative assessment of endometrial vascularization during uterine disorders. The aim of this study was to assess, through contrast-enhanced ultrasound (CEUS) exam, the vascularization in endometrial microvessels in CEH-pyometra in order to evaluate the possibility of application in this syndrome. In twelve female dogs with clinical symptoms related to pyometra, echographic, Color Doppler and CEUS exams were performed. Histopathological examination revealed severe CEH and pyometra, immunohistochemical stain with CD 34 confirmed the presence of angiogenesis. CEUS exam revealed a widespread, intense and rapidly developing homogeneous enhancement of the hyperplastic endometrium with absence of signal only in cystic areas. All parameters of the quantitative analysis were not significantly influenced by region of interest dimension and position. CEUS may improve not invasive evaluations in the CEH-pyometra syndrome and virtually in CEH-mucometra.

Abstract

In cystic endometrial hyperplasia (CEH)–pyometra syndrome, toxic factors and endometrial remodeling culminate in changes characterized by exudative and degenerative inflammatory reaction. Recent studies on hemodynamic found an increased blood flow and lower vascular resistance in uterine arteries, suggesting color Doppler ultrasound as an adjunctive tool for quantitative assessment of endometrial vascularization during pyometra. The aim of this study was to assess, through contrast-enhanced ultrasound (CEUS) exam, the vascularization in endometrial microvessels in CEH-pyometra in order to evaluate the possibility of application in this syndrome. In twelve female dogs with clinical symptoms related to pyometra, B-mode, color Doppler and CEUS exams were performed. In CEH-pyometra uteri, histopathological examination revealed severe CEH and pyometra, immunohistochemical stain with CD 34 confirmed the presence of angiogenesis. CEUS exams revealed a widespread, intense and rapidly developing homogeneous enhancement of the hyperplastic endometrium, with absence of signal only in cystic areas. All parameters of the quantitative analysis were not significantly influenced by region of interest dimension and position. CEUS has the potential to improve clinical not invasive evaluations in the CEH-pyometra syndrome and virtually in CEH-mucometra.

The bitch around parturition

Around parturition, a bitch has to cope with various challenges such as hormonal changes, whelping, nursing, milk production, and uterine involution. Monitoring the health of bitches in this period is essential to detect potential illnesses and dystocia early. In that regard, it is elementary to know the normal progress and parameters during pregnancy, parturition and in the puerperium. Some research has been published in the past 50 years giving insights into hormonal and functional changes and findings including definitions of normal parturition and dystocia or puerperal conditions. However, taking a closer look into the literature reveals that for some issues heterogeneous data and varying conclusion were presented, indicating that further research is required. This paper gives an overview on endocrinology and methods to predict the time of parturition in the dog. Furthermore, the stages and mechanisms of parturition and signs of dystocia and puerperal health monitoring are discussed. Fields in which contradictory data have been published include for example the decline of hematocrit in the second half of pregnancy, the body temperature immediately before and after parturition, the interpretation of ultrasound findings, and the length of the canine puerperium. Even if thresholds are not clear for each parameter, examinations such as regular temperature measurement or ultrasound are important to monitor the bitches' health status. Nevertheless, for the practitioner it is important to know that research findings for some parameters used in daily practice are controversial.

Advanced ultrasound techniques in small animal reproduction imaging

Ultrasonography is the imaging technology of choice for the evaluation of the reproduction system and of pregnancy in both humans and animals. Over the past 10 years, there have been significant technological improvements of the equipment, while new technologies have been developed. Doppler, contrast-enhanced ultrasonography, elastography, and 3D/4D ultrasonography are advanced ultrasound techniques that have been designed as methods to increase the diagnostic sensitivity of two-dimensional (b-mode) ultrasound, and not as stand-alone tests. The basic physics as well as the advantages and limitations of these advanced ultrasound methods are briefly described. In the reproductive diagnostics of small animals, these techniques have gained an increased popularity as proved by the increased publication of several reports that are also briefly summarized in this review. Clinical applicability is to date limited because of a lack of research on the diagnostic value in concrete situations. Future research projects should focus also on standardization of the used techniques, on determination of thresholds to discriminate between healthy or diseases or fertile versus infertile and on the predictive value of advanced ultrasound findings. Continuing development and optimization of different ultrasound techniques as well as the increase of related scientific interest and worldwide research promises that the clinical interest on the use of advanced ultrasound techniques will increase in future.

Echocardiographic and electrocardiographic parameters during the normal postpartum period in toy breeds of dogs

The aim of this study was to evaluate echocardiographic and electrocardiographic parameters during the normal canine postpartum period. Twenty clinically healthy pregnant bitches of toy breeds (11 Miniature poodles, five Yorkshire terriers, two Maltese terriers and two Bichons Frises) were evaluated on days -3, 3, 10, 17, 24, 38, 52 and 80 relative to parturition (day 0). During the first postpartum week, the width of the interventricular septum in systole, the shortening fraction and the left atrium size decreased, while the left ventricle internal diameter in systole and end systolic stress increased. There were progressive decreases in the velocity of circumferential fibre shortening, stroke volume, cardiac output, and mitral E and A wave values. Systolic blood pressure increased markedly during the first postpartum week to gradually increase thereafter. Heart rate and corrected QT interval progressively decreased, while P wave amplitude increased. QRS complex amplitude decreased in the second week after parturition and then increased during the following weeks. In conclusion, there were changes in systolic function and some structural adaptive changes in the bitch during the first 80days postpartum. In addition, maternal heart rate and corrected QT interval decreased, while P wave and QRS amplitudes increased.

Uterine blood flow evaluation in bitches suffering from cystic endometrial hyperplasia (CEH) and CEH-pyometra complex

Doppler ultrasound is a useful diagnosis tool to evaluate uterine blood flow in different canine reproductive states. The aim of this study was to describe and compare uterine blood flow in bitches suffering from cystic endometrial hyperplasia (CEH) and CEH-pyometra complex (CEH-P). Ninety diestrous bitches were clinically, hematologically, and ultrasonographically classified into four groups: (1) clinical signs, leukocytosis, CEH, and uterine luminal contents (CEH-P, n = 31); (2) asymptomatic bitches with CEH and uterine contents (CEH-C, n = 15); (3) asymptomatic bitches with CEH without uterine contents (CEH, n = 16); and (4) normal diestrous bitches (ND, n = 28). The widest cross-sectional diameter and uterine wall thickness (W) of uterine horns were measured using two-dimensional ultrasound. Peak systolic velocity and end diastolic velocity of uterine arteries were measured by Doppler ultrasound in all the bitches. Peak systolic velocity and end diastolic velocity were higher in CEH-P than in CEH-C, CEH, and ND (P < 0.01); although both parameters did not show differences among the latter three groups (P > 0.1). Conversely, resistance index (RI) reported lower values in CEH-P than that in the other three groups (P < 0.01), being ND higher (P < 0.01) than both CEH-C and CEH which did not differ between themselves (P > 0.1). When all the bitches were considered, correlation between RI and cross-sectional diameter was r = -0.69 (P < 0.01) and between RI and uterine wall thickness was r = -0.02 (P > 0.1). It is concluded that the uterine artery blood flow velocity of bitches suffering from pyometra was higher, not only from normal bitches, but also from females with endometrial hyperplasia. Furthermore, endometrial hyperplasia, accompanied or not by luminal contents, had a higher blood flow velocity than normal uterus. Hemodynamic parameters appear as useful markers to differentiate uterine pathologic conditions.