Anatomical Variations of the Blood Vascular System in Veterinary Medicine. The Internal Iliac Artery of the Dog. Part Two

The aim of this study was to investigate the variability of the internal pudendal artery. Two hundred and thirty‐two pelvic halves from 116 adult dogs were examined. Twenty‐six anatomical variations were found, thirteen occurring in more than 5% of the dogs. Anatomical variations were grouped in relation to the origin of the prostatic/vaginal arteries, middle rectal artery, urethral artery, ventral perineal and caudal rectal arteries. The chi‐squared test was used to analyse differences in sex, side of the body, profile and size, and the results were considered statistically significant when P ≤ 0.05. An identical vascular pattern in both hemipelvises was found for most of the anatomical variations described.     

双峰驼髂内动脉的形态学观察

采用血管内灌注有色油画颜料的方法,解剖观察了双峰驼髂内动脉的分支及分布情况.髂内动脉是骨盆部动脉的主干,其分支有脐动脉、臀前动脉、闭孔动脉、臀后动脉和阴部内动脉.阴部内动脉的分支有阴道动脉、直肠中动脉、会阴腹侧动脉和阴蒂动脉.在双峰驼未见有会阴背侧动脉.还就双峰驼和其它家畜髂内动脉的解剖学特点进行了比较讨论.     

Anatomical and Morphometric Variations in the Arterial System of the Domestic Cat

We document the anatomical architecture and frequency of occurrence of variations in the branching pattern of the brachiocephalic artery and the origin of the internal iliac arteries in the domestic cat, a widely used model organism in both anatomical training and research. Based on the study of 56 preserved specimens, we observed three distinct arrangements in the branching pattern of the brachiocephalic artery. The most common pattern (52% of the examined specimens) was that in which the brachiocephalic artery was divided into two branches, the left common carotid artery and a common branch for the right subclavian artery and the right common carotid artery. The frequency of occurrence of each variation type was independent of the gender and body size. The internal iliac arteries originated caudal to the point at which the external iliac arteries branched off from the abdominal aorta. However, the portion of the abdominal aorta between the external and internal iliac arteries varied greatly in length and was not significantly correlated with its width, nor with body size or gender. This study is the first to report and quantify the occurrence of such variations in North American cats. Given the anatomical similarity between the cat and other felids, the results of this study can be applied to other species, including endangered species.     

Anatomical Variations of the Blood Vascular System in Veterinary Medicine: The Internal Iliac Artery of the Dog — Part Three

The aim of this study was to analyse and describe the variability of the umbilical artery. Two hundred and thirty‐two pelvic halves from 116 adult dogs were examined. To study the permeability of the umbilical artery, ten adult dogs, nine newborns and thirteen foetuses between 35 and 50 days of gestation were also used. In relation to the origin of the umbilical artery, six anatomical variations were found. From which five involved a cranial (n = 4) or caudal (n = 1) relocation of its origin, and in one case (n = 1), the umbilical artery arose from the median sacral artery. In eight cases, the umbilical artery gave off the prostatic (n = 1) or vaginal (n = 7) arteries. The permeability of the umbilical artery was the most significant anatomical variation: permeability was detected in 45% (106 of 232 pelvic halves) of all cases, from which 36 were males and 70 females. Interestingly, an equal vascular permeability in both hemipelvises was found for 82% of the dogs, thus additional data related to such feature of the umbilical artery was also recorded. In accordance with the statistical study, the main anatomical variations described showed significant values for gender, side of the body, size and profile variables.     

Arterial distribution to the pelvic cavity and pelvic limb in the pampas deer (Ozotoceros bezoarticus,Linnaeus 1758)

This research is a study about the arterial vascularization of pelvic cavity and pelvic limb in pampas deer. For this study, 25 dead animals were used. The vascularization of the organs was investigated using a latex injection technique. Two animals were injected in the common carotid artery with contrast to cardiac angiography, and then, radiographs were taken. The aorta showed the two external iliac arteries, and after a short course, the aorta ended in two internal iliac arteries. The median sacral artery was originated from the dorsal surface cranially to the emergence of the internal iliac arteries. The last one gave off parietal (iliolumbar, cranial and caudal gluteal arteries) and visceral (umbilical and internal pudendal arteries) branches. The external iliac artery gave as first branch the deep circumflex iliac artery which was divided into a cranial and a caudal branch. After a short distance from the external iliac artery, the femoral and deep femoral arteries were originated. The deep femoral artery gave origin to the pudendoepigastric trunk and to the medial femoral circumflex artery. Based on the arterial distribution of the pelvic cavity and pelvic limb in the pampas deer, it is concluded that the internal iliac artery has a pattern of intermediate development. In reference to the distribution of the external iliac artery and its branches, the pattern of development is the cranial tibial type.     

Direct cutaneous arterial supply to the tail in dogs.

Cutaneous arterial blood supply to the tail was evaluated in 12 dogs. Subtraction radiography of internal iliac artery and distal aorta angiography in 3 of these dogs was used to determine arterial blood supply to the tail from the median sacral and lateral caudal arteries. Dissection of the tail in 8 canine cadavers revealed bilateral subcutaneous location of lateral caudal arteries following tail amputation. An axial pattern flap based on the lateral caudal arteries contributed to the reconstruction of a large caudodorsal cutaneous defect in a dog. An axial pattern flap based on the lateral caudal arteries following tail amputation may be indicated to aid reconstruction of large caudodorsal cutaneous defects of the trunk in dogs.     

Anatomical anomalies and variations of main thoracic vessels in dogs: a computed tomography study

IntroductionThere is scarce information about the prevalence of anomalies and anatomical variations of the main great thoracic vessels in dogs, particularly in dogs without congenital heart disease.AnimalsThe study included 878 privately owned dogs.Material and methodsComputerized tomography (CT) thoracic studies carried out between 2011 and 2014 for a variety of reasons were reviewed. The prevalence of anomalies and anatomical variations of the aorta and vena cava, the arterial branches of the aortic arch and the main branches of the intrathoracic veins in dogs with no evidence of congenital heart disease was evaluated. Poor-quality CTs, CTs with thoracic pathology that impaired visualization or those of young dogs with clinical evidence or suspicion of congenital cardiac disease were excluded.ResultsEight hundred two CT studies were analysed. Eight dogs (1%) showed an anatomic anomaly. The most common anomaly was an aberrant retroesophageal right subclavian artery (n = 7, 0.8%). One dog showed a dilated azygos vein secondary to an interrupted vena cava. Three types of branching of the common carotid arteries were observed: both arteries arising at the same point (type I: n = 506/742; 68.2%), separated (type II: n = 212/742; 28.6%) or from a common trunk (type III: n = 24/742; 3.2%).ConclusionsMajor anatomical variations or anomalies of the main great thoracic vessels in dogs without congenital cardiac disease were rare. An aberrant retroesophageal right subclavian artery was the most common anomaly found. Three slight variations of common carotid artery branching were identified. These findings might be of relevance for surgical or catheterization procedures.     

Effects of triple pelvic osteotomy on anatomic structures of the pelvic region in the dog

Triple pelvic osteotomy has been used in dogs to maintain normal form and anatomical function of the hip in canine hip dysplasia. Pelves subjected to triple pelvic osteotomy undergo several architectural changes of different magnitudes. The aim of this study was to determine the positional changes of the anatomical structure of the pelvis after unilateral triple pelvic osteotomy in five mongrel dogs. Atrophy of the middle gluteal muscle, reduction in tension of the external and internal obturator muscles, compression on the caudal gluteal vein and entrapment of the sciatic nerve at the level of the ilial body were the most remarkable findings in the study. From an anatomical standpoint, it is suggested that the lateral rotation of the acetabulum should be kept minimal to guarantee least alterations in the normal anatomic architecture of the pelvic region.     

Gross anatomy of the portal vein and hepatic artery ramifications in dogs: corrosion cast study

The anatomical variations of the portal vein and the hepatic artery ramifications were analysed on liver corrosion casts in 20 dogs as a possible aid in the surgical management of the organ. The portal vein ramified similarly in all dogs. It divided into the smaller right portal branch from which vessels for the caudate process and both right lobes arose and the substantial left portal branch, which supplied the remaining liver portions and in 12 cases also the dorsal part of the right lateral lobe. Right lateral, right medial and left branches are the major arteries originating from the hepatic artery; however, their origin and course varied among individual animals. In 10 livers, the right lateral and the left branches originated from the hepatic artery, while the right medial branch arose from the left branch and usually supplied the right medial lobe solely. In nine livers, the right medial branch arose directly from the hepatic artery and supplied quadrate lobe and gallbladder as well, while in one liver the common artery, which subsequently divided into lobar branches, branched away from the hepatic artery. An additional branch for the caudate process, originating directly from the hepatic artery, was observed in 10 livers. Certain liver portions received the arterial blood from two major branches, which was particularly characteristic for the right medial lobe (six livers) and caudate process (10 livers). The course of the major arterial branches was also variable, although they proceeded in close anatomical relationship with the portal vein branches. The left arterial branch accompanied the left portal branch on its dorsal aspect (15 cases) or crossed it from the caudal aspect (five cases). The right lateral branch crossed the initial parts of the left and right portal branches either from cranial (12 cases) or caudal aspects (eight cases), while the right medial branch always crossed the left portal branch from its caudal aspect.     

Anatomical variation of arterial supply to the rabbit spleen

The rabbit, which is widely used as an experimental animal and is also popular as a companion animal, has a flat and elongated spleen with the longitudinal hilus running along its visceral surface. The spleen receives via the hilus an arterial supply that is essential for splenic nutrition and normal functioning. However, the distribution and variation of the arteries to the spleen have not been studied in detail. This study investigated anatomical variations of splenic arterial supply in 33 New Zealand White rabbits with a colored latex injection into arteries. We also examined whether the length of the spleen correlated with the number of the splenic branches of the splenic artery. The splenic artery always arose as the first independent branch of the celiac artery and ran along the splenic hilus to usually provide 6 (range, 3 to 10) splenic branches to the spleen. There was a moderate correlation (R=0.6) between the number of splenic branches and the longitudinal length of the spleen. The splenic branches often arose as a trunk or trunks in common with short gastric arteries. The number of common trunk(s) was usually 1 (range, 0 to 4). The data showed that the pattern and number of arterial branches to the spleen varied according to the individual animal, suggesting that such variations should be considered when performing experimental and veterinary surgical treatments in rabbits.     

Arterial supply of the penis in agoutis (Dasyprocta prymnolpha, Wagler, 1831)

The arterial vascularization of agoutis’ penis (Dasyprocta prymnolopha) were analysed using ten male adults from ‘Núcleo de Estudos e Preservação de Animais Silvestres da Universidade Federal do Piauí’ (FUFPI/IBAMA n° 02/99). Among the total number of specimens, six animals had natural death and were members of the research collection of the Laboratory of Anatomy, and four were killed after anaesthesia. Stained bi‐centrifugated‐Cis‐I‐4 latex was injected in arterial vessels responsible for penis vascularization throughout the abdominal portion of aorta. The samples were fixed in 10% formaldehyde solution and arteries were dissected. The penile artery is originated as a branch of internal pudendal artery. At the level of ischiatic arch, the penile artery project two branches, the penile dorsal and the deep arteries; those arteries irrigates the penile dorsal surface and the corpus cavernosum penis. The penile dorsal arteries have an independent course up to the glans penis. Based on the conditions of this work a remarkable similarity regarding the distribution of vessels destined to the agouti penis when compared to other domestic, wild and lagomorph rodents as rabbits.     

The Hindlimb Arterial Vessels in Lowland paca (Cuniculus paca,Linnaeus 1766)

This study aims to describe the origin and distribution of the hindlimb arterial vessels. Five adult lowland pacas (Cuniculus paca) were used. Stained and diluted latex was injected, caudally to the aorta. After fixation in 10% paraformaldehyde for 72 h, we dissected to visualize and identify the vessels. It was found out that the vascularization of the hindlimb in lowland paca derives from the terminal branch of the abdominal aorta. The common iliac artery divides into external iliac and internal iliac. The external iliac artery emits the deep iliac circumflex artery, the pudendal epigastric trunk, the deep femoral artery; the femoral artery originates the saphenous artery, it bifurcates into cranial and caudal saphenous arteries. Immediately after the knee joint, the femoral artery is called popliteal artery, which divides into tibial cranial and tibial caudal arteries at the level of the crural inter‐osseous space. The origin and distribution of arteries in the hindlimb of lowland paca resembles that in other wild rodents, as well as in the domestic mammals.     

Arterial Vascularization and Morphological Characteristics of Adrenal Glands in the Pampas Deer (Ozotoceros bezoarticus,Linnaeus 1758)

This research presents morphological characteristics of adrenal glands and a demonstration of arterial vascularization in the Pampas deer, which is considered to be in extreme danger of extinction. A total of ten deer constituted the material of the study. Vascularization of organs was investigated by using latex injection technique. Left adrenal glands were basically supplied by coeliac, cranial mesenteric, renal and lumbal arteries. The arterial vascularization of the left adrenal glands was very complex in comparison with right adrenal glands. In two examples, branch of the lumbal artery was divided into phrenic caudal artery and cranial adrenal artery. In six examples, it was observed that the caudomedial and ventral regions of the left adrenal glands were also supplied by thinner branches that stemmed from second left lumbal artery. Besides, coeliac and cranial mesenteric arteries also gave off shorter branches supplying the cranial region of the left adrenal glands in five examples. It was determined that two branches originated from abdominal aorta directly for supplying left adrenal glands in only two examples. In four examples, two caudal adrenal arteries stemmed separately from left renal artery in a short distance. Arterial vascularization of right adrenal glands was more constant and supplied by lumbal and renal arteries. The adrenal glands were generally oval or round shaped. In only two examples, left adrenal glands were ‘V‐’ or heart‐shaped. There was no significant difference (P > 0.05) in sizes between right and left adrenal glands.     

COMPUTED TOMOGRAPHY ANGIOGRAPHY FOR EVALUATION OF PULMONARY EMBOLISM IN AN EXPERIMENTAL MODEL AND HEARTWORM INFESTED DOGS

This study was performed to characterize pulmonary embolism with computed tomography pulmonary angiography in experimental pulmonary embolism and heartworm infected dogs. In the experimental group, there were pulmonary changes after pulmonary embolism induction as follows: hypoattenuating round filling defects in pulmonary arteries, arterial dilations with straight and abrupt cut‐off appearances in the pulmonary embolism regions, pulmonary infarctions, a cavity formation and spontaneous pneumothorax, and emboli migration. In the heartworm‐infected group, three out of eight dogs developed pulmonary embolism, especially in the right caudal arteries. Arterial dilations with typical tortuosity were also identified, mainly in the right caudal arteries in five dogs. Computed tomography pulmonary angiography can be an important imaging modality in the diagnosis of pulmonary embolism and the evaluation of pulmonary arterial and parenchymal changes in dogs.     

Arteries of the Carotid Body in Rats

The arterial blood supply of 40 carotid bodies in 20 Wistar rats of both sexes, aged 10-12 weeks (250-350 g), was examined by light microscopy. The carotid bodies of all rats were supplied by only one carotid body artery. The average diameter of the carotid body arteries was 40 microns. This artery arose either from the external carotid artery (97.5%) or the occipital artery (2.5%). There was an intimal cushion at the origin of the carotid body artery. The carotid body artery, after reaching the caudal pole of the carotid body, divided into the first-order branch. In the carotid body, the paranchyma was divided into the second-order branch. The carotid body artery was of the muscular type.     

Contrast-enhanced ultrasonography for evaluation of the blood perfusion of sciatic nerves in healthy dogs

Blood supply to the peripheral nerves is essential for fulfilling their structural and functional requirements. This prospective, experimental, exploratory study aimed to assess the feasibility of contrast-enhanced ultrasonography (CEUS) for evaluating blood perfusion of the sciatic nerve in normal dogs. Contrast-enhanced ultrasonography examinations were performed on the bilateral sciatic nerves after bolus injection of Sonazoid™ (0.015 mL/kg) in 12 healthy Beagles for 150 s. Then, qualitative assessment of the wash-in timing, degree and enhancement patterns, and quantitative measurement of the peak intensity and time to peak intensity were performed from the sciatic nerve. The results were compared to those obtained from the adductor muscle around the nerve and caudal gluteal artery. After contrast agent injection, the sciatic nerve was enhanced at approximately 13–14 s, immediately after wash-in of the caudal gluteal artery. The peak intensity of the sciatic nerve was significantly lower than that of the caudal gluteal artery and higher than that of the adductor muscle. The time to peak intensity was significantly slower than that of the caudal gluteal artery; but was not significantly different from that of the adductor muscle. There were no significant differences in the peak intensity and time to peak intensity between the left and right sciatic nerves. These results demonstrate the feasibility of CEUS to assess blood perfusion of the sciatic nerve in healthy dogs qualitatively and quantitatively. This result from healthy dogs could serve as a reference for further studies that evaluate the sciatic nerve under pathological conditions.     

Investigation and clinical application of a novel axial pattern flap for nasal and facial reconstruction in the dog

OBJECTIVE: To describe the vascular supply to a facial skin flap based at the commissure of the lip in the dog and report on its use in four dogs. STUDY DESIGN: Experimental and prospective clinical study. Animals Five canine cadavers and four client-owned dogs. METHODS: In the cadavers, the ventral aspect of the zygomatic arch, the ventral margin of the caudal mandible and the wing of the atlas were marked as anatomical boundaries of a skin flap that was elevated from the subcutaneous tissues to the level of the medial canthus of the eye. Methylene blue dye and barium sulphate solution were independently infused through a common carotid (three dogs) or facial artery (two dogs) catheter. Distribution of dye throughout the harvested skin was assessed subjectively. After contrast infusion the flap was excised and radiographed. The technique was used to reconstruct large facial or nasal defects in four dogs after tumour or skin lesion excision. RESULTS: Cadaver dissections and contrast studies clearly demonstrated three direct cutaneous arteries, the superior and inferior labial arteries and the angularis oris artery, arborising within the base of the flap. A separate direct cutaneous branch of the angularis oris artery was identified. An arterial plexus was identified within the distal flap, within which this artery communicates with the transverse facial artery and a cutaneous branch of the masseteric artery. Dye infusion caused discolouration of the elevated skin and vasculature within the flap. The flap survived in all clinical cases with marginal distal necrosis in one dog. CONCLUSIONS: The complex facial flap described is perfused by three direct cutaneous arteries and functions reliably in clinical cases.     

Validation of noninvasive blood pressure equipment: which peripheral artery is best for comparison studies in dogs?

Objectives

1) To determine which peripheral artery commonly used for invasive arterial blood pressure (IBP) monitoring yields the least bias when compared with noninvasive blood pressure (NIBP) values obtained at the antebrachium of the dog, and 2) to identify and describe differences in systolic (SAP), mean (MAP) and diastolic arterial pressures (DAP) among different anatomical locations.

A systematic study of brain base arteries in the wild boar (Sus scrofa scrofa)

This study aimed at describing and systematizing the arteries of the base of the brain of the wild boar (Sus scrofa scrofa). Thirty-three heads were used, of which 30 were injected with latex, and three with acrylic dental resin through the common carotid arteries. The brain carotid artery arose from the rostral epidural rete mirabile, and divided into a rostral and a caudal branch. The rostral branch gave off the middle cerebral artery and then continued as rostral cerebral artery. The latter branched into lateral rhinal, internal ethmoidal and medial rhinal arteries. The rostral cerebral artery joined its contralateral homologue, becoming the single rostral inter-hemispheric artery. The caudal branch emitted the caudal cerebral artery and the tectal arteries, and then fused with the branch of the opposite antimere, joining the basilar artery. The rostral cerebellar arteries derived from this point. The basilar artery originated from the anastomosis between the arteries derived from the caudal epidural rete mirabile of each antimere. The basilar artery extended rostrally, giving off as main collateral branch the caudal cerebellar artery. The basilar artery presented a significant decrease in diameter before joining the caudal branches of the brain carotid arteries. The cerebral arterial circle was rostrally and caudally closed.