Ultrasonographyc study of the postpartum uterine involution in bitches after cesaerean section


Ferri, S.T.S., Vicente, W.R.R., & Toniollo, G.H.. (2003). Estudo da involução uterina por meio da ultra-sonografia (modo-B) em cadelas submetidas a cesariana. Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 55(2), 167-172. Retrieved January 27, 2016, from http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352003000200007&lng=en&tlng=pt.


RESUME

They used 15 bitches after caesarean section and later ultrasound examinations series in B mode (real-time) to investigate the uterine diameter on days 0, 3, 7, 14 and 21 post-cesarean section, in order to verify the influence of surgery on uterine involution. The results (mean and standard deviation in centimeters) recorded for the days studied were: 3.99 + 0.71; 3.27 + 0.51; 2.60 + 0.54; 2.01 + 0.34; 1.28 + 0.24. The post-cesarean uterine involution followed the same pattern of normal birth postpartum period as well as the characteristics of the ultrasound images. The cesarean delivery did not influence the pattern of uterine involution.

 

ABSTRACT

Fifteen pregnant bitches Were Observed by serial B-mode (real time) ultrasonography to describe the characteristics and diameter of the involuting uterus on days 0, 3, 7, 14, and 21 post-cesarean. The average and standard deviation, in centimeters, presented on Those Days after cesarean section, Were, respectivamente 3.99 + 0.71, 3.27 + 0:51, 0:54 + 2.60; 2:01 + 0:34 + 0:24 and 1:28. Under the conditions of this report it is Concluded que cesarean section did not influence the normal uterine involution.

 

INTRODUCTION

The dystocia in dogs is a common occurrence, ranging from 5% to 100% in some breeds (Eneroth et al., 1999), defined as difficult birth or uterus's inability to expel the fetus. Classically, it has maternal or fetal origin, the concept of bankruptcy of the three components of the birthing process: expulsive forces, pelvic canal and fetus (Bojrab, 1983).

Treatment options of dystocia range from the use of oxytocin to obstetric manipulations and cesarean section, and each option may be exercised with varying success. Darvelid and Linde-Forsberg (1994) found that of 182 cases of dystocia in 65.8% was necessary to carry out caesarean section, even after obstetric manipulation and drug treatment. This was also mentioned by Stolla et al. (1999) in 464 cases of dystocia, of which 19.9% responded to drug treatment, 5.1% required digital manipulation and forceps and 75% required cesarean section. Moon et al. (1998) conducted a retrospective study of 776 caesareans, noted 58% of emergencies.

If you compare the ultrasound used in human obstetrics with used in small animals, the latter is seldom used as a method of diagnosis and the postpartum period, after vaginal delivery or postcesarean. In human medicine, in the immediate postpartum period, about 10 days after delivery eutocic or cesarean section, we use ultrasound to monitor the involution of the uterus (Galli et al., 1993), as an aid to diagnosis of menorrhagia, placenta accreta, metritis and thromboembolism detection (Galli et al., 1993; Sherer, 1998), and postoperatively to evaluate the uterine and abdominal scarring (Galli et al., 1993).

The sonographic evaluation of uterine scarring is of great importance in the prevention of scar rupture in future pregnancies and also in a future labor (Schiotz, 1991; Kaplan et al., 1994).

The evaluation of the reproductive tract in pets by ultrasound has become more frequent over the last 10 years, but detailed studies of the postpartum period are still scarce (Root, Spaulding, 1994; Moon et al., 1998).

The ultrasound postpartum bitches allows evaluate the characteristics of the uterus, as its architecture and diameter (Yearger, Concannon, 1990; Mahaffey et al., 1995). In the first week postpartum, the body and the uterine horns are shown enlarged and irregular in shape, being better identified in the dorsal position to the urinary bladder. The diameter of the uterus in the region of placental sites, usually ovoid, is 2.5 + 0.3 cm and interplacentários sites of 1.0 to 1.5 cm. On day 24, the mean diameter of placental sites is from 1.0 to 1.4cm and the regions interplacentárias 0.6 to 0,9cm (Pharr, Post, 1992; Root, Spaulding, 1994).

Yearger and Concannon (1990) and Pharr and Post (1992) concluded that knowledge of these characteristics can by means of ultrasound, serial examinations or not, early identification of pathological processes. This was confirmed by Sanchez (1998), to observe a decrease pattern of the uterine diameter normal delivery and that changes in this pattern indicate likely pathological processes.

According to Moon et al. (1998) there is need for more detailed studies of the pathophysiological processes that can affect the postpartum period, both eutocic birth as cesarean.

This study aimed to register via ultrasound scans the events of uterine involution in bitches for 21 after cesarean section and evaluate the influence of surgery on uterine involution.

 

MATERIAL AND METHODS

15 pregnant dogs were used, with and without mixed breed, aged between two and seven years, body weight ranging from 5 to 20kg and in great health. During the last week of gestation were monitored for symptoms of the prodromal phase of delivery. With the onset of clinical signs and body temperature drop characteristic of this phase, the animals underwent caesarean section.

The surgical technique used was the same described by Bojrab (1983), Slatter (1993) and Fossum et al. (1997). A hysterectomy was performed in the uterine body, near the fork and hysterorrhaphy, on two levels with continuous sutures (Cushing and Lembert), using chromic catgut 2-0, needled. To laparo dermorrafia and nylon threads were used 0 and 2-0, needle, respectively, and applied to separate simple points.

After cesarean section, the animals underwent ultrasound exams on days 0 (day of surgery), 3, 7, 14 and 21. We used ultrasound machine (PetScope Ò - Tokimec - Japan) with transducer 7.5 MHz linear and 5 MHz convex. The images obtained in the experiment were recorded in printer (Video Printer R & B - Mitsubish Ò) coupled to the device. The survey was done with the animal in right lateral decubitus, after prior shaving of the left flank region, using appropriate gel for ultrasound (Mahaffey et al, 1995;. Yearger, Concannon, 1995). From each studied pictures of day, measurements were made (at least five) standard in interplacentários and uterine body sites, both near the fork.

The results were analyzed using descriptive statistics to determine measures of central tendency (mean) and variability (standard deviation and coefficient of variation).

 

RESULTS AND DISCUSSION

The mean and standard deviation of the diameter, in centimeters, for each day studied were as follows: 3.99 + 0.71; 3.27 + 0.51; 2.60 + 0.54; 2.01 + 0.34; 1.28 + 0.24. The average progressively declined almost linearly, following a pattern similar to that reported by Sanchez (1998), but the delivery postpartum eutocic the decline was more pronounced in the first week.

In the literature they not found reports that could explain this difference between the first week of post-caesarean section and postpartum eutocic. It is believed that the actual surgery may have influence during the first seven days, although the surgical technique is described in the treaties traditional surgery. According Toniollo et al. (1999), the type of the suture thread and do not influence the uterine involution. Mijten et al. (1997) cited the most important is to avoid as much as possible tissue trauma, ischemia and hemorrhage, which are more important than the type of yarn and suture.

This was considered normal since no animal showed until the last day of study, clinical findings and ultrasound images that could indicate a pathological process.

The uterine involution, both eutocic postpartum and in post-cesarean section showed a similar pattern of reduction in diameter when compared to the various consultation papers presented in Tab. 1. According to Galli et al. (1993), there is no difference in involution rate of Caesarean section and vaginal delivery in women.

 

 

The uterine diameter of animals with large and small litters had similar averages, as expected for the sample group. The number of pups did not influence the rate of post-cesarean uterine involution, a fact suggested by Sanchez (1998) for puerperal eutocic delivery.

In dogs, it is believed that the parity order (Yearger, Concannon, 1990), age (Phar, Post, 1992) and animal size (Root, Spaulding, 1994) did not influence the rate of uterine involution.

From the literature datos and based on the results obtained it is believed that there is more individual variation in diameter than attributed to exogenous factors such as surgery.

The ultrasound images (Fig. 1 and 2) showed similar characteristics to those reported in the literature (Yearger, Concannon, 1990, Phar, Post, 1992; Root, Spaulding, 1994; Sanchez, 1998; Kang et al., 1999).

 

 

The uterus on day 0 post-cesarean section (Fig. 1 A and B) is hypertrophied, irregularly shaped, can be observed with resolution layers that constitute it. The serous is characterized as most external hyperechoic line surrounding a more hypoechoic area, the myometrium, which at this stage is thickened. The innermost layer, the endometrium, which in most cases presents an irregular and easy definition because the echogenic contrast to the luminal contents mostly presents anechoic.

In the first week (Figure 1 C and D, Fig. 2A and B), the uterus apreesentou eliptiforme in the form of stratification with well defined wall can be observed in all layers.

On day 14 (Fig. 2 C and D), the uterus is cylindrically shaped, well defined, showing little luminal contents, no longer possible to observe the suture. On day 21 (Fig 2 E) presents a cylindrical reduced diameter, is not possible in most cases to define the layers, in that they are as thin lines. The luminal content is almost imperceptible.

The suture image is only observed in the first week (Fig. 1A and E), most evident in the first three days of observation. It is characterized as hyperechoic region in the uterine body close to its bifurcation, it is not possible to distinguish other characteristic. This finding would have been better if you used other material for the suture, to remain longer in the uterine scar as suggested Hoskins et al. (1991).

The sonographic findings are similar to those reported by Kang et al. (1999), i.e., the uterus initially flaccid features manner that varies from circular to polygonal to 16.5 + 3.7 days after birth eutocic, when it becomes circular. Regarding the observation of the layers, these researchers reported that it is possible to accurately distinguish the four uterine layers until the seventh day. This distinction has become increasingly difficult due to reduced uterine diameter. The luminal contents is possible to detect up to 25.0 + 6.4 days postpartum.

The ultrasonographic features observed during the post-cesarean section postpartum period are similar to those reported in the literature for eutocic delivery (Sanchez, 1998; Kang et al., 1999).

According to the literature, in human obstetrics ultrasound is of great importance in normal postpartum and after cesarean section as semiotic technique for the diagnosis and prognosis of puerperal disorders, uterine scarring and possible complications in future pregnancies (Schiotz, 1991; Galli et al., 1993; Kaplan et al, 1994)..

In the veterinary medical literature consulted did not meet citations on the use of ultrasound for the evaluation of involution and the uterine scar after cesarean section in bitches but only quote in cattle (Mijten et al., 1997).

It is known that in cattle cesarean use is controversial because of adhesion problems, especially in the area of hysterorrhaphy, which can cause reproductive problems (Mijten et al., 1997).

While these aspects are known in humans and cattle, they have not been well studied in dogs. It is not known if surgery caesarean section compromise fertility (internal and external adhesions) and future dynamics of birth, or even if the scar would support the rapid uterine growth in the final third of pregnancy and labor, with no your rupture.

 

CONCLUSIONS

The cesarean delivery performed with the surgical technique and conditions described in this work did not influence the pattern of uterine involution. With the standardization of uterine involution is expected to have a tool that aids the diagnosis of puerperal disorders and providing knowledge to future studies in canine veterinary obstetrics.

 

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Received for publication on March 21, 2002
Received for publication after modifications, on November 25, 2002
Research sponsored by FAPESP

* Mailing Address: Rua Barão José Miguel, 330, lighthouse, 57055-160 - Maceio, AL, E-mail: monasanchez@ig.com.br


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