Caudal Cava Vein Research Articles

Congenital Extrahepatic Portosystemic Deviation in a Mixed-Breed Dog

Background: Portosystemic deviation (PSD) is a congenital or acquired vascular anomaly that allows an abnormal blood flow from the portal vein directly to the systemic circulation. This liver by-pass avoids hepatic metabolism of several toxins. Congenital PSDs are usually solitary and extra-hepatic, with a high incidence in pure-breed dogs. Acquired PSDs are usually multiple and occur as a consequence of portal hypertension. Surgery is the definitive treatment. Clinicians and surgeons may present difficulties in the propaedeutic of animals with PSD. This paper aims at reporting a successful surgical treatment of a solitary extra-hepatic congenital PSD in a mixed-breed dog.Case: A 7-month-old mixed-breed dog, female, spayed, weighing 8 kg, was presented with a history of sudden syncope after feeding. Complementary exams revealed normocytic hypochromic anaemia, hypoalbuminemia and increased alanine aminotransferase and alkaline phosphatase. Abdominal ultrasound revealed an anomalous vessel inserted in the caudal cava vein, compatible with a congenital extra-hepatic PSD. Computed tomography revealed the anomalous vessel, with 1,1 cm of diameter, originated from the cranial mesenteric vein and it inserted in the cranial margin of the caudal cava vein. A medical support was started with hydration, metronidazole, lactulose, probiotic and Hepatic diet. After 15 days the dog was submitted to surgery and a 5 mm ameroid constrictor ring was placed to gradually close the anomalous vessel. The dog recovered well and an abdominal ultrasound was repeated after 30 days, showing the ameroid constrictor ring ring in the left cranial abdominal region, occluding the PSD close to its insertion in the caudal cava vein. The patient was followed up for more than three years, gained weight and presented a healthy normal life.Discussion: Although PSD is more often diagnosed in pure-breed dogs, this paper reports a case in a mixed-breed dog. However clinical signs and the age of onset were compatible with this pathology. Dogs with PSD may present neurological, gastrointestinal and urinary disorders, related to failure of the detoxification process and toxin by-pass to the systemic circulation. Young dogs are usually presented overdue underdevelopment, reduced body height or weight loss as described in this report. Hepatic encephalopathy is a result of the production of ammonia and several other toxins, which escapes hepatic metabolism, and once they remain liposoluble, they are able to cross-pass the blood-brain barrier and produce the neurological signs, which might be more pronounced after feeding, as in the reported case, although this dog presented only mild neurological signs. The haematological and biochemical findings in the dog of this report were also compatible with PSD. Hypoglycemia, hypocholesterolemia, increased of bile acids and serum ammonia may also be present but they were not demonstrated in this case. Abdominal ultrasound was able to identify the anomalous extra-hepatic vessel which was precisely described by computed tomography, which allower surgical planning. Medical support is recommended for the patient´s clinical estabilization, as performed in this case. Surgery is the treatment of choice for congenital solitary PSD, as in the reported case, and placement of the ameroid constrictor is the most employed technique, as performed. Patient´s improvement starts in the day after surgery and it is completed within a couple months. The patient of this report did not present any complications in the postoperative period and for more than three years, showing total remission of the clinical signs and good life´s quality.

Descrição anátomo-topográfica do coração da paca (Agouti paca)

Background : : : : The domestic animals heart is a conical hollow viscera, surrounded by pericardium, laterally compressed, accompanying the thorax shape. Atriums constituted the heart basis and their auricles partially bound the initial portion of the aorta and pulmonary trunk. In mammals, heart is kept suspended in the thoracic cavity and the pericardic sac is fixed dorsally by great veins and arteries roots, and ventrally fixed to the sternum, although its fixation to the diaphragm varies among species. This paper aimed to describe morphological aspects of the heart of the paca, the second biggest Brazilian rodent. Materials, Methods & Results : There were used 12 hearts of adult pacas for this study, obtained from the UNESP, Jaboticabal, SP, which died due fights or anesthesia during bandages or radiograph exams. The thoracic aorta was filled with colored latex and the animal was set in a 10% formaldehyde solution for at least 72 hours. The thoracic cavity was dissected and hearts individualized and measured with a paquimeter, lateromedially, craniocaudally and dorsoventrally. The paca heart is placed between the first and fifth intercostal space (ICS), in a craniocaudal oblique position; its basis is craniodorsally positioned, on the middle third between the first and second ICS and its apex is located near the sternodiaphragmatic joint, on the fifth ICS, tilted to the left antimere. The heart is surrounded by pericardium, which from ventrocaudally is originated the sternopericardic ligament, that continues as phrenopericardic ligament. At the heart basis, the rising of the pulmonary trunk was observed and the conus arteriosus formed a typical projection. The aorta also rised from the heart basis and its arch, which was caudally curved, crossed dorsally the pulmonary trunk; the right cranial and caudal cava veins drained to the right atrium. There is a left cranial cava vein, which surrounded the left atrium and joined the right caudal cava vein on the right atrium. The azygos vein joins the right cranial cava vein and four pulmonary veins drained to the left atrium. At palpation, a hard structure on the rising of the aorta was observed, similarly to a cartilaginous tissue, which would be part of the cardiac skeleton. The left and right coronary arteries were observed in all hearts. Discussion : The paca heart is anatomica and topographically similar to those of domestic mammals, differing from them for being placed one intercostal space more cranial and due to the presence of two cranial cava veins, the left and the right ones, besides the presence of the caudal cava vein. This vascular description is similar to that of small rodents, as rats and mice. In paca heart, the sinus venous, the terminal crest, the oval fossa, the atrioventricular valvae, the papillary muscles and tendinous cords, besides smooth atriums and auricles covered by pectinate muscles, were observed. The sternopericardic ligament, which is dorsally elongated as phrenopericardic ligament, is similar to the one present in humans, pigs, castors, and different from the one observed in carnivorous, that presents the phrenopericardic ligament and from the one of horses and ruminants, which present the sternopericardic ligament.

Effects of pneumoperitoneum and body position on the morphology of the caudal cava vein analyzed by MRI and plastinated sections

Pneumoperitoneum and patient positioning are essential factors during laparoscopic surgical procedures. They cause hemodynamic and anatomical changes in several abdominal organs among which the caudal cava vein (CCV) is involved. Hemodynamic changes in this vein (decreased venous return) have been described in the porcine model, but how the vein morphology and size is affected at different abdominal levels is unknown. We sought to assess the morphological and morphometrical changes in the CCV of the pig caused by pneumoperitoneum and the reverse Trendelenburg position by in vivo magnetic resonance imaging (MRI). Six pigs were scanned via MRI under four situations: S1, control (no pneumoperitoneum); S2, control in the reverse Trendelenburg position; S3, pneumoperitoneum (14 mmHg); and S4, pneumoperitoneum in the reverse Trendelenburg position. MRI and plastinated body sections were used to evaluate the topography, morphology and cross-sectional area of the CCV. Two portions of the CCV were differentiated: a prehepatic portion (located between the vertebral levels L1-T15) with flat and irregular morphology, and a hepatic portion (between T14-T11) that was almost rounded. The reverse Trendelenburg position caused an increase in the lumen affecting mainly the prehepatic portion, while pneumoperitoneum caused a decrease in the total vascular lumen, exerting a greater effect on the hepatic portion. The combination of both situations resulted in a further decrease in the vascular area and global morphological changes. The pneumoperitoneum and reverse Trendelenburg position caused morphological and morphometrical changes in the prehepatic and hepatic portions of the CCV, which should assist in gaining a better understanding of the hemodynamic changes described in the literature.

Preliminary results with a training program for thoracoscopic atrial fibrillation therapy

Novel devices have been designed for the treatment of atrial fibrillation (AF) using minimally invasive approaches. This study aimed to determine the usefulness of a sheep model for training in cardiac surgical ablation using a minimally invasive approach in an experimental hands-on training course. After initial training using a laparoscopic pelvic trainer, 15 sheep were subjected to surgery by six thoracic surgeons attending a hands-on thoracoscopic course. Dissection to the posterior wall of the pulmonary veins was followed by insertion of a microwave device around both the caudal cava vein and the pulmonary veins. The complications were recorded, and the effectiveness of the surgery was evaluated by complete deployment of the microwave device. The animals were killed after completion of the procedure. Isolation of the cava vein and the pulmonary veins and placement of the microwave probe were performed successfully for 10 animals using a complete thoracoscopic approach. Two animals died during the procedure. The main complications of the procedure were hemorrhage and difficulty isolating the blood vessels using a minimally invasive procedure. After the training period, the thoracoscopic surgical maneuvers were accurate and reliable. The technical feasibility of performing safe and efficient thoracoscopic placement of a microwave device in a sheep model was demonstrated in this study, suggesting that the results of this study are a useful contribution to the development of an animal model for surgical training and experimental cardiac surgeries.

Doppler evaluation of maternal and foetal vessels during normal gestation in queen

The aim of this work is to evaluate the haemodynamic characteristics of maternal and foetal vessels during normal pregnancy in queens, using colour Doppler and pulsed wave Doppler ultrasonography, in order to obtain information about maternal and foetal circulation. The blood waveforms of the uteroplacental arteries, aorta, caudal cava vein and umbilical cord of the fetuses were recorded weekly in seven healthy pregnant queens. Also, the measurements of peak systolic, end diastolic velocities, resistance and pulsatility indices were carried out. Uteroplacental blood flow was biphasic while the ones of the umbilical artery and aorta were first systolic and then diastolic. The caudal cava vein showed a typical waveform of venous vessels. During gestation the EDV and PSV of foetal vessels increased (alpha<0.05) while the PI and RI of all vessels examined decreased (alpha<0.05) except for the IP of the aorta. The Doppler ultrasonography, also in queens, can be used to evaluate the characteristics of maternal and foetal vessel flow and their progressive changes during pregnancy. This study can be considered the basis for further contribution in diagnosing and monitoring high-risk pregnancies in Veterinary Medicine.

Anomalia congênita em vasos da base do coração de um potro

Anomalias congênitas do coração e de grandes vasos estão entre as mais comuns encontradas em animais, porém são raras em eqüinos. Este relato descreve uma anomalia cardíaca que apresenta confluência entre a parede da aorta e do tronco pulmonar, ramificação da veia cava caudal no átrio esquerdo com presença de válvula e conseqüentemente posição errônea do coração na cavidade torácica de um potro da raça Quarto-de-Milha encontrado morto após o nascimento. O diagnóstico foi realizado pela associação dos achados macroscópicos durante a necrópsia e o exame histopatológico realizados no Curso de Medicina Veterinária- UNESP-Araçatuba.

Doppler evaluation of maternal and fetal vessels during normal gestation in the bitch

The aim of this work is to evaluate the haemodynamic characteristics of maternal and fetal vessels during normal pregnancy in bitches, using Colour and Pulsed wave Doppler ultrasonography, in order to obtain more information about maternal and fetal circulation. The blood waveforms of the uteroplacental arteries, aorta, caudal cava vein and umbilical cord of the fetuses were recorded weekly in 16 pregnant bitches. Also, the measurements of Peak Systolic, End Diastolic Velocities, Resistance and Pulsatility Indices were carried out. Uteroplacental blood flow was biphasic while the ones of the umbilical artery and aorta were first systolic and then diastolic. The cava showed a typical waveform of venous vessels. During gestation the EDV and PSV of fetal vessels increased ( α < 0.05) while the PI and RI of all vessels examined decreased ( α < 0.05) except for the IP of the Aorta. The Doppler ultrasonography was used to study the characteristics of maternal and fetal vessel flow and their progressive changes during pregnancy. This study can be considered a further contribution in diagnosing and monitoring high-risk pregnancies in Veterinary Medicine.

Computed Tomography (Ct) of the Liver of the Dog by a Six‐generation CT Scanner and Intravenous Contrast Medium

By computed tomography the liver has an intermediate degree of attenuation, with a CT value (HU) between 70 and 75. However, this number may vary according to the generation of the apparatus, the use of contrasts medium, the efficiency of the detector, etc. The purpose of the present work was to evaluate the liver of the dog and related structures by means of a six‐generation spiral CT scanner (Toshiba Ex Vision [[Au: please provide manufacturers details for ‘Toshiba Ex Vision’: city, state code (if USA) and Country]]), and the previous injection of intravenous contrast medium via cephalic vein. Four half‐breed mature dogs (4–6 years, 15–20 kg) were used, two males and two females. The dogs were anaesthetized and kept over a stretcher in sternal recumbency. To evaluate the liver two different CT windows with different window width and window level were applied: soft tissue window (WW 652; WL ‐34) and mediastinal‐vascular window (WW 352; WL 220). The CT images obtained allowed an excellent resolution at the level of the hepatic lobules, the gall bladder, the porta vein, the hepatic artery, the caudal cava vein, etc. The attenuation shades of these structures were very similar in the two used windows, however a better contrast was obtained with the soft tissue window.

Toracoscopia em eqüinos: técnica e emprego como método de avaliação da cavidade pleural

Toracoscopia é o método de visibilização da cavidade torácica através de endoscópio rígido ou flexível, indicado como exame auxiliar para diagnóstico das diversas afecções do tórax. Pode ser realizada com o animal sob anestesia geral ou em posição quadrupedal através de anestesia local associada ou não a sedativos. Neste trabalho, foram utilizados seis eqüinos hígidos, que foram submetidos a toracoscopia, em posição quadrupedal, nos dois hemitórax, com intervalo de 15 dias entre cada procedimento. Durante o exame, pôde-se observar as diversas estruturas da cavidade torácica, tais como: músculo diafragma (porção muscular e tendínea), hiato esofágico, mediastino, aorta, troncos dorsal e ventral do nervo vago, ducto torácico, veia ázigos, veias intercostais, músculos intercostais, costelas, tronco nervoso simpático, tronco vascular toracocervical, traquéia, pulmão (lobo cranial e caudal), esôfago, pericárdio, veia cava caudal, nervo frênico e linfonodos aórticos. Discretas alterações foram observadas ao exame físico, laboratorial e ultra-sonográfico no período pós-operatório, sem que trouxessem prejuízos ao desenvolvimento do experimento e recuperação do animal. A toracoscopia mostrou ser exame de auxílio importante, pela facilidade, rapidez de execução, ampla visibilização da cavidade pleural e trauma mínimo ao paciente.

Toracoscopia em eqüinos: estudo comparativo entre duas técnicas de abordagem

A toracoscopia tem sido cada vez mais indicada como exame auxiliar para diagnóstico das diversas afecções do tórax. Com o objetivo de comparar duas técnicas de abordagem para inspeção da cavidade pleural, foram utilizados 16 animais hígidos, que foram submetidos à toracoscopia, dos quais dez sob anestesia geral com intubação orobronquial seletiva e seis em posição quadrupedal sob sedação associada à anestesia local. Foram abordados os hemitórax direito e esquerdo, com intervalo de 15 dias entre cada procedimento. Durante a abordagem, pôde-se observar as diversas estruturas da cavidade torácica, a saber: músculo diafragma (porção muscular e tendínea), hiato esofágico, mediastino, artéria aorta, troncos dorsal e ventral do nervo vago, ducto torácico, veia ázigos, veias intercostais, músculos intercostais, costelas, tronco nervoso simpático, tronco vascular toracocervical, traquéia, pulmão (lobo cranial e caudal), esôfago, pericárdio, veia cava caudal, nervo frênico, linfonodos aórticos. A realização do exame toracoscópico com os animais sedados e mantidos em posição quadrupedal possibilitou a identificação de um maior número de estruturas. A toracoscopia mostrou ser exame de grande auxilio, pela facilidade e rapidez de execução e ampla inspeção da cavidade pleural, mas a escolha de posicionamento do animal irá depender do órgão ou estrutura a ser preferencialmente abordada. Nos casos em que se optar pelo decúbito, há que se considerar o emprego da ventilação mecânica com intubação orobronquial seletiva.

Contribuição ao estudo dos elementos vasculares, arteriais e venosos, do hilo renal em suínos (Sus scrofa domestica)

This work is based on the exam of thirty sets which particularly comprise kidneys, blood vessels and correspondents of the aorta artery and caudal cava vein taken from young swines, being twenty male and ten female. A careful study was made about the swines, the hilar branches of the artery and the sources of the renal vein as well as the global behavior of these blood vessels taken in isolation. According to the results we arrive to the following conclusions: 1. The number of arterial branches of the renal artery vary from two to five on the right, and from two to eight on the left; 2. The number of the veined sources of the renal vein vary from two to four on the right and one to four on the left; 3. There is a positive correlation for the right kidney as well as the left one, between the number of the hilar branches, arterial and veined. As far as sex is concerned the previous statement is only valid for the right kidney.

Contribuição ao estudo dos ramos arteriais hilares, justahilares e extrahilares em rins de cavalos(Equus caballus)

This study is based on the exam of 30 sets including kidneys, vassels, ureteres and tracts corresponding to the aorta artery and caudal cava vein: these sets were taken from adult horses, 12 male and 18 female, and the hilar, juxtahilar and extrahilar branches of the renal artery were studied, as well as the whole behaviour of these branches taken in isolation. The results allow the following conclusions: 1. From three to ten branches of the right renal artery enter the hilar region; and so do from three to eleven branches of the left renal artery. 2. From one to six branches of the right and left renal arteries occupy juxtahilar position. In 1 case on the right side, there were no juxtahilar vassels. 3. From one to fifteen branches of the right renal artery enter the extra hilar region, and so do from one to eighteen branches of the left renal artery. 4. In the hilar region the branches of the renal artery are mostly peripheric. 5. In the juxtahilar portion the branches of the renal artery are predominantly central. 6. In the extrahilar portion the branches of the renal artery are generally central. 7. The renal artery shows the same number of branches bilaterally in 6 cases. 8. There is positive correlation both to the left and to the right kidney among the number of hilar, juxtahilar and extrahilar branches independently of sex, statistically speaking.