Morphology and anatomic-surgical segmentation of the spleen of Pecari tajacu Linnaeus, 1758

Abstract

The spleen is a secondary lymphoid organ with importance in clinical surgery. Due this and the lack of data in the literature, the current paper analyzes the organ´s morphology and segmentation in collared peccaries. Twenty animals were used at the Center for the Multiplication of Wild Animals of the Universidade Federal Rural do Semi-Ãrido, Mossoró RN Brazil. The spleen was removed with the splenic pedicle preserved, identifying the lineal artery and vein. Fragments from four spleens were harvested to be examined under light microscopy. They were fixed in a paraformaldehyde solution 4% and buffered with sodium phosphate 0.1M, pH 7.4. Routine histological techniques were performed: the spleens were dehydrated in increasing ethanol concentrations; diaphanized in xylol; soaked in paraffin; 7µm cuts were obtained and stained by hematoxylin-eosin or Gomori trichrome technique. The intraparenchemal vascularization of sixteen spleens were analyzed by latex or vinilite acetate perfusal of the lineal artery and vein and the organ fixed, respectively, in a water solution of formaldehyde 10% or immersed in a solution of sulfuric acid 30%. The collared peccary´s spleen had a tongue-like shape. Under the microscope, the spleen featured an intermediary type, with a great amount of white pulp, a predominance of red pulp and few trabeculae. The spleen´s segments had three different regions, namely dorsal, middle and ventral, in irrigation terms with a possible surgical removal of the dorsal region. Knowledge on the angio-architecture and segmentation of the spleen will be a contribution for surgical procedures in wild species, having a great relevance when partial splenectomy is required.