Anatomia topográfica e ultrassonográfica do fígado, vesícula biliar, esplenopâncreas e rins da cobra-do-milho (Pantherophis guttatus)

Abstract

The present study aimed to describe the topographic and ultrasonographic anatomy of the liver, gallbladder, splenopancreas and kidneys of the corn snake (Pantherophis guttatus), in order to obtain a guide for ultrasonographic scanning and to standardize the echographic aspects of these organs in terms of number, dimensions, contours, shape, echogenicity and ecotexture. Five clinically healthy animals of the species P. guttatus and a cadaver of the same species without macroscopic alterations indicative of disease were used. The cadaver was submitted to anatomical dissection and after locating the organs of interest, the topography of each was identified by measuring the percentage of body length they occupied in the snake's coelomic cavity. The ultrasonographic examination was carried out in the other animals with scanning in the craniocaudal direction and, based on the previously obtained topographic indicators, the organs were located and evaluated. In anatomical dissection, the location of the liver, gallbladder, splenopancreas and right and left kidneys was easily identified and measured based on the percentage of body length they occupied, being located between 22.0 and 37.7%, 49.6 and 51, 9%, 51.1 and 53.5%, 73.1 and 81.1% and 76.3 and 82.6% respectively. Organs were easily identified by ultrasonographic examination in all animals with the obtained topographic indicators. The liver showed a fusiform and unilobed shape, regular and well-defined contours delimited by a thin hyperechogenic capsule, homogeneous hypoechogenic parenchyma with the presence of a central hepatic vein. The gallbladder showed a fusiform shape, regular and well-defined contours delimited by a thin hyperechogenic wall, repletion with homogeneous anechogenic content and non-visible vessels. The splenopancreas showed a fusiform and unilobed shape, regular and well-defined contours by a thin hyperechogenic capsule, homogeneous echogenic parenchyma and non-visible vessels. The left and right kidneys showed a fusiform and multilobulated shape with regular contours defined by an echogenic capsule. There was a strong correlation between the independent variables length, maximum body circumference and animal weight with the dimensions of each organ. Also, high coefficients of determination for linear regression were obtained from the correlations. Through indices obtained by dividing the independent variables by organ size, it was possible to determine confidence intervals to interpret the normality of organ size in this animal species. The location of coelomic organs based on percentage of body length acts as an effective ultrasound scanning guide in P. guttatus snakes. In adult corn snakes, the liver, gallbladder, splenopancreas, and kidneys can be adequately evaluated by ultrasound.