Técnicas Anatômicas de Preparação de Vísceras Secas e de Angioarquitetura para Visualização da Ramificação da Artéria Mesentérica Cranial em Cães e Gatos Techniques for Anatomical Preparation of Dried Viscera and Angioarchitecture of Cranial Mesenteric Artery Branching of Dogs and Cats

Background: The study of the arterial vascularization of the abdominal cavity viscera is essential on the process of learning anatomy. For authors, various anatomical techniques can be used for the preservation of structures, allowing the exploration and visualization of the organs shape in many different ways. Among the techniques there is the angioarchitecture of viscera, with or without the utilization of formaldehyde. The aim of this paper is to describe a technique for anatomical preparation of the intestines (small and large) of dogs and cats using dried viscera and angioarchitecture, to facilitate the study and visualization of the cranial and caudal mesenteric arteries branching. Materials, Methods & Results: Twenty pieces of intestine of dogs and two of cats were used. The intestine was removed from the duodenum to the cranial portion of the rectum, the root of the mesentery was sectioned as well as the cranial and caudal mesenteric arteries. The part was washed, then the caudal and cranial mesenteric and pancreaticoduodenal arteries were ligated, latex was injected in the cranial mesenteric artery and the sample remained immersed in a 10% acetic acid aqueous solution. The cranial portion of the rectum was ligated and, through a cannula into the duodenum, air was insufflated until the viscera were distended. Following that, the part was positioned and fixed, exposed to continuous ventilation until complete drying and sprayed with turpentine, insect repellent and varnish. After thirty days, the samples were conditioned, fifteen in a glass cabinet and seven, isolated, in closed boxes, with a significant difference between the types of conditioning regarding the proliferation of fungi and insect invasion. After four months of preparation it was possible to observe that the distension each viscera had changed. Discussion: There are few standardized protocols regarding the preparation of dried viscera angioarchitecture, more particularly, of intestines. Latex is more effective for the display of structures with larger calibers and, in addition, this material does not retract and does not alter the vessel walls, being moderately resistant and elastic when solidified. For these reasons it was the chosen material for the development of this project. Regarding the technique of dry viscera preparation of the digestive system, it is indicated to isolate the segments of intestine removing the mesentery, but in this study it was maintained, preserving the organ anatomy. The latex injection technique can be performed in several ways due to the large number of vessels to be cannulated. In this study, the cranial mesenteric artery was cannulated after removal of the viscera from the abdominal cavity and without any difficulty. Preparation of the part proceeded, keeping the intestinal segments united, facilitating the visualization of vessels. Samples maintained separately in boxes had its aspect better preserved than those who remained in a larger space. Authors report that viscera with excessive fat should be treated with carbon tetrachloride or a similar solvent in order to prevent deterioration. In this research 30% of the preparations had their final aspect impaired, even with the use of turpentine. According to the findings it is possible to conclude that the technique of angioarchitectonic molding of dry intestines of dogs and cats is feasible, has low cost and allows excellent visualization of arterial branching and easy handling. It features also some technical advantages such as reducing the weight of the parts, avoiding the use of tanks of formaldehyde and allowing its use for a virtually unlimited period.