title: Intermediate veins in swine (Sus scrofa domestica) kidney: authors' own anatomical classification.
abstract: BACKGROUND
  The use of domestic swine as an experimental animal is increasing steadily. Swine organs are the best animal model for urological experiments. The aim of the study was to evaluate the course and size of intermediate veins in a swine kidney. The research results were compared with the results obtained from studies on venous vascularisation of human kidneys. The knowledge of the above-mentioned vessels is important both in human and veterinary medicine and will enable researchers to compare and notice differences between human and swine organs.
  
  
  METHODS
  The study was conducted on 94 kidneys, 47 right ones and 47 left ones, taken from adult domestic swines (Sus scrofa domestica). The kidneys were prepared and corrosion casts were made.
  
  
  RESULTS
  The average lumen diameter of secondary intermediate veins was 7.96 mm. The average diameter of the primary intermediate veins directly inserted in the renal vein (type A) and primary intermediate veins inserted in the secondary intermediate veins (type B) amounted to 6.7 mm and 4.75 mm, respectively. The average length of primary intermediate veins of type A was 21.91 mm. Secondary intermediate veins were shorter - on average 19.83 mm. Primary intermediate veins of type B were on average 12.91 mm long.
  
  
  CONCLUSIONS
  Intermediate veins are formed in the area of vascular anastomoses on the level of renal papillae. The following veins can be distinguished: primary intermediate veins of type A and type B, as well as secondary intermediate veins. Secondary intermediate veins and primary intermediate veins of type A run only on the ventral side of the renal pelvis. Only the primary intermediate veins of type B can run on the dorsal side. From the anatomy point of view, intermediate veins of swine kidneys are very similar to equivalent vessels in human kidneys as regards their run and anastomoses.
authors.affiliation: Department of Normal and Clinical Anatomy, Interfaculty Chair of Anatomy and Histology, Medical University of Lodz, Poland. jacek.szymanski1@umed.lodz.pl.
authors.forename: J
authors.initials: J
authors.lastname: Szymański
authors.forename: M
authors.initials: M
authors.lastname: Polguj
authors.forename: M
authors.initials: M
authors.lastname: Topol
authors.forename: P
authors.initials: P
authors.lastname: Oszukowski