Open Access

ARTICLE

Anatomical and histological equivalence of the human, canine, and bull vas deferens

Dean E. Leocadio¹, Allen R. Kunselman², Timothy Cooper³, Jairo H. Barrantes⁴, J.C. Trussell¹

1 Department of Urology, State University of New York at Upstate, Syracuse, New York, USA
2 Health Evaluation Sciences, Milton S. Hershey Medical Center, Hershey, Pennsylvania, USA
3 Department of Comparative Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania, USA
4 Department of Pulmonary and Critical Medicine, Wayne State University, Detroit, Michigan, USA
Address correspondence to Dr. JC Trussell, Department of Urology, State University of New York at Upstate, 750 East Adams Street, Syracuse, NY 13210 USA

Canadian Journal of Urology 2011, 18(3), 5699-5704.

Abstract

Introduction: Several animal models have been used for in vitro experimentation and surgical training exercises involving the vas deferens. The canine model is currently considered the standard for both in vivo and ex vivo studies. However, due to increasing costs associated with canine experimentation and in accordance with the principles of refine, reduce, and replace, a novel model that is cost-effective and easily obtainable is desired. We compared the morphology of the bull vas deferens with that of the human and canine vas deferens.
Materials and methods: Bilateral vas deferens tissue from human (n = 6), canine (n = 6), and bull (n = 5) specimens were compared. Outer diameter (OD), inner diameter (ID), and microscopic measurements of the luminal mucosa and muscularis were determined from each sample. Histological comparisons were performed by a single pathologist. Data were analyzed using Two One-Sided Tests (TOST) Analysis of Equivalence.
Results: According to TOST statistical analysis, the vassal inner diameter was equivalent across all three species. Microscopic measurements also showed equivalence in both mucosal thickness (human-canine and human-bull) and muscularis thickness (canine-bull). Histologically, all three species demonstrated similar characteristics.
Conclusions: The vas deferens of the human, canine, and bull are morphologically and histologically comparable. It is reasonable to conclude that the bull vas deferens can be substituted for the human vas in both in vitro testing and microscopic vasovasostomy simulation exercises. Bull vas specimens are cost-effective, provide ample tissue length, and are readily available.

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