title: Volume calculation of rats' organs and its application in the validation of the volume relation between the abdominal cavity and the hernial sac in incisional hernias with "loss of abdominal domain".
abstract: BACKGROUND
  The calculation of the volume ratio between the hernia sac and the abdominal cavity of incisional hernias is based on tomographic sections as well as the mathematical formula of the volume of the ellipsoid, which allows determining whether this is a giant hernia or there is a "loss of domain". As the images used are not exact geometric figures, the study of the volume of two solid organs of Wistar rats was performed to validate these calculations.
  
  
  OBJECTIVE
  To correlate two methods for determining the volume of the kidney and spleen of rats, comparing a direct method of observation of the volume with the mathematical calculation of this value.
  
  
  METHODS
  The volume of left kidney, geometrically more regular, and spleen, with its peculiar shape, of ten animals was established in cubic centimeters after complete immersion in water with the aid of a beaker graduated in millimeters. These values ​​were compared with those obtained by calculating the same volume with a specific mathematical formula: V = 4/3 × π × (r1 x r2 x r3). Data were compared and statistically analyzed by Student's t test.
  
  
  RESULTS
  Although the average volume obtained was higher through the direct method (1.13 cm3 for the left kidney and 0.71 cm3 for the spleen) than the values ​​calculated with the mathematical formula (0.81 cm3 and 0.54 cm3), there were no statistically significant differences between the values ​​found for the two organs (p>0.05).
  
  
  CONCLUSIONS
  There was adequate correlation between the direct calculation of the volume of the kidney and spleen with the result of mathematical calculation of these values ​​in the animals' studies.
authors.affiliation: Universidade Nove de Julho, São Paulo, SP, Brazil.
authors.forename: Luz Marina Gonçalves de
authors.initials: LM
authors.lastname: Araújo
authors.affiliation: Universidade Nove de Julho, São Paulo, SP, Brazil.
authors.forename: Leonardo Carvalho
authors.initials: LC
authors.lastname: Serigiolle
authors.affiliation: Universidade Nove de Julho, São Paulo, SP, Brazil.
authors.forename: Helbert Minuncio Pereira
authors.initials: HM
authors.lastname: Gomes
authors.affiliation: Universidade Nove de Julho, São Paulo, SP, Brazil.
authors.forename: Daren Athiê Boy
authors.initials: DA
authors.lastname: Rodrigues
authors.affiliation: Universidade Nove de Julho, São Paulo, SP, Brazil.
authors.forename: Carolina Marques
authors.initials: CM
authors.lastname: Lopes
authors.affiliation: Universidade Nove de Julho, São Paulo, SP, Brazil.
authors.forename: Pedro Luiz Squilacci
authors.initials: PL
authors.lastname: Leme
mesh_terms: D034841:Abdominal Cavity; D000818:Animals; D006555:Hernia, Ventral / Q000473:pathology*; D007668:Kidney / Q000473:pathology*; D055641:Mathematical Concepts; D009929:Organ Size; D051381:Rats; D017208:Rats, Wistar; D013154:Spleen / Q000473:pathology*