The distribution of the jejunal arteries in the cat

Vascularization of the gastrointestinal tract of the bottlenose dolphin (Tursiops truncatus, Montagu 1821)

Odontocetes primarily rely on fish, cephalopods, and crustaceans as their main source of nutrition. In the digestive system, their polygastric complex exhibits similarities to that of their closest terrestrial relatives such as cows, sheep, and giraffes, while the entero-colic tract shares similarities with terrestrial carnivores. The morphology, caliber, and structure of the odontocete intestine are relatively constant, and, since there is no caecum, a distinction between the small and large intestine and their respective subdivisions is difficult. To address this issue, we used the intestinal vascularization pattern, specifically the course and branching of the celiac artery (CA) and the cranial and caudal mesenteric arteries (CrMA and CdMA). A series of pictures and dissections of 10 bottlenose dolphins (Tursiops truncatus) were analyzed. Additionally, we performed a cast by injecting colored polyurethane foam in both arteries and veins to measure the caliber of the arteries and clarify their monopodial or dichotomous branching. Our results showed the presence of multiple duodenal arteries (DAs) detaching from the CA. The CrMA gave origin to multiple jejunal arteries, an ileocolic artery (ICA), and, in six cases, a CdMA. In four specimens, the CdMA directly originated from the abdominal aorta. The ICA gave rise to the mesenteric ileal branches (MIB) and mesenteric anti-ileal branches and the right colic arteries (RCA) and the middle colic arteries. From the CdMA originated the left colic and cranial rectal arteries (LCA and CrRA). The measurements revealed a mixed monopodial and dichotomous branching scheme. The analysis of the arteries and their branching gave us an instrument, based on comparative anatomy, to distinguish between the different intestinal compartments. We used the midpoint of anastomoses between MIB and RCA to indicate the border between the small and the large intestine, and the midpoint of anastomoses between LCA and CrRA, to tell the colon from the rectum. This pattern suggested an elongation of the duodenum and a shortening of the colic tract that is still present in this species. These findings might be related to the crucial need to possess a long duodenal tract to digest prey ingested whole without chewing. A short aboral part is also functional to avoid gas-producing colic fermentation. The rare origin of the CdMA on the CrMA might instead be a consequence of the cranial thrust of the abdominopelvic organs related to the loss of the pelvic girdle that occurred during the evolution of cetaceans.

Endoscopic and surgical treatment of non-neoplastic proximal duodenal ulceration in dogs, and anatomical study of proximal duodenal vascularisation

OBJECTIVES

Proximal duodenal ulceration is often characterised by continuous bleeding, and treatment is challenging. The aims of this study were to investigate the role of vascularisation in proximal duodenal ulceration and describe clinical aspects, endoscopic features and treatment in dogs.

MATERIAL AND METHODS

Polyurethane foam casts of gastroduodenal vessels were obtained from five dogs which had died from disorders unrelated to the digestive system. In addition, 12 dogs having proximal duodenal ulcers diagnosed by endoscopic examination were enrolled in a treatment trial. After the endoscopic diagnosis of a duodenal ulcer, all the dogs were treated medically and, in the absence of resolution, were subsequently treated by endoscopic electrocauterisation or by surgery.

RESULTS

A submucosal vascular network was evident in all the casts, with a prominent venous plexus seen exclusively in the first half inch of the duodenum. In clinical cases, on endoscopic examination, the duodenal ulcer was located at the proximal part of the duodenum, involving the mesenteric portion of the wall. The dogs not responding to medical treatment (6/12) were treated with endoscopic electrocauterisation, surgical coagulation or resection of the proximal duodenal portion. All the dogs survived until discharge, and the median survival time following discharge was 107.5 days.

CLINICAL SIGNIFICANCE

Based on the anatomical details highlighted in this study, the continuous bleeding observed in our patients may have been due to the prominent venous plexus evidenced at the level of the proximal duodenum. Surgical and endoscopic treatments in six patients resolved the ulcer bleeding with no recurrences noted during follow-up.

Surgical Anatomy of the Gastrointestinal Tract in Cats

In cats, the gastrointestinal tract is one of the regions in which surgical procedures are most frequently performed by veterinary surgeons; therefore, knowledge of the surgical anatomy of the feline gastrointestinal tract is of high importance. The main surgical procedures performed include gastrotomy, gastrectomy, enterotomy, and enterectomy, as well as procedures in the liver and pancreas. There are also anatomical differences between dogs and cats, increasing the need for deep knowledge of the anatomy treated in the different surgical approaches. The aim of the present review is to describe in detail the anatomy of the gastrointestinal tract in cats highlighting the anatomical regions of significant importance in different surgical procedures.

Arterial branching pattern of the cranial mesenteric artery in the degu (Octodon degus)

BACKGROUND

The cranial mesenteric artery exhibits a species-specific ramification pattern that adapts to the morphology of the intestinal tract. The degu is a strictly herbivorous rodent with a well-developed large intestine with a spiral loop in the ascending colon; therefore, the cranial mesenteric artery likely demonstrates a degu-specific ramification pattern. Thus, we traced the cranial mesenteric artery to establish the detailed ramification pattern of the branches.

METHODS

Eighteen male degus were injected with 0.3-0.8 ml of a latex mixture and water at a 1:1 ratio in conjunction with red acrylic paint coloring using a catheter inserted into the thoracic aorta. The cranial mesenteric artery was traced using a surgical microscope and photographed using a digital camera.

RESULTS

The arteries emerging from the cranial mesenteric artery exhibited frequent variations in number, distribution area, anastomosis pattern, and branching order. In the most frequent cases (22%), the cranial mesenteric artery sequentially gave rise to caudal pancreaticoduodenal, middle colic, right colic, jejunal, and ileocolic arteries. The right and middle colic arteries exhibited four different ramification patterns. In the most common cases (67%), the middle and right colic arteries emerged independently from the cranial mesenteric artery. The former was distributed to the transverse and descending colon, whereas the latter sent branches to the spiral loop of the ascending colon.

CONCLUSIONS

The complex ramification pattern of the right colic artery in the degu may be an adaptation to the characteristic running pattern of the ascending colon. Thus, we present the first comprehensive report of the arterial branching pattern of the cranial mesenteric artery in the degu.

Novel combination method of wide-range serial sectioning and 3D reconstruction visualizing both macro-level dynamics and micro-level interactions in an attempt to analyze the female pelvic floor

The present report presents details of the method for combining wide-range serial sectioning and 3D reconstruction using an adult cadaver. For several decades, anatomists have utilized a variety of non-destructive three-dimensional (3D) visualization methods to complement gross anatomical analysis methods. These include vascular casting for the visualization of vascular morphology and micro-CT for the visualization of bone morphology. However, these conventional methods are restricted by the properties and sizes of the target structures. Here, we introduce a method to conduct 3D reconstruction based on wide-range serial histological sections from adult cadavers, which overcomes previous restrictions. An attempt at 3D visualization of the female pelvic floor muscles provides a detailed description of the procedure. Supplemental video and 3D PDF files allow multifaceted observation of 3D images. Wide-range serial sectioning visualizes morphology beyond the scope of conventional methods, while 3D reconstruction enables non-destructive 3D visualization of any structure that can be observed on a histological section, including skeletal muscle, smooth muscle, ligaments, cartilage, connective tissue, blood vessels, nerves, lymph nodes, and glands. The novel combination of both methods is instrumental in meso-anatomy, a discipline intermediate between macro-anatomy and micro-anatomy.

Description of the arterial supply and venous drainage of the abdominal viscera in the puma (Puma concolor) (Linnaeus, 1771)

Detailed descriptions of the abdominal vasculature have not been reported on Puma concolor; thus, herein we provided a thorough description. Our findings include the following: a celiac artery branching into the hepatic and gastrolienal arteries, and this latter further branched into the left gastric, the left gastroepiploic, the lienal and three more arteries that supplied the greater omentum. We also found a cystic artery that derived from the right gastroduodenal artery; a right gastric artery that derived from the right hepatic artery; and an antimesenteric ileal artery that derived from the lateral cecal artery. The right gastric vein did not form the gastroduodenal vein as in other species, but it drained directly into the portal vein. Also, a middle pancreaticoduodenal vein was identified as the last branch of the cranial mesenteric vein. Finally, the left caudal phrenic vein drained into the left renal vein. The abdominal blood supply described herein corresponds to a single individual; further reviews are desirable to corroborate our observations and to detect potential intraspecific anatomical variations.