Segmental histomorphometry of the porcine ureter for use as a vascular xenograft

Purpose:  To histologically quantify the different tissues that make up the porcine ureter, (epithelial, connective, and muscular tissue) in the three segments labelled: cranial, middle and caudal, in order to identify the segment most compatible for use as a vascular graft.

Methods:  Fifteen porcine ureters were collected, divided into the three segments, and the samples were stained with hematoxylin and eosin, picrosirius red and Weigert’s resorcin-fuchsin. The immunohistochemistry technique was applied for alpha-smooth muscle actin. Collagen fibers, muscle, epithelium, and elastic fibers tissue were quantified, in the entire ureter, and divided into hemispheres, comparing the different segments.

Results:  When comparing hemisphere segments, significant differences were observed (p < 0.01) for collagen and muscle tissue, with the cranial segment presenting the greatest amount of these components when compared to the middle and caudal. No significant difference was observed between the segments when comparing the entire ureters.

Conclusions:  After comparing the segments by hemisphere, the cranial segment presented a slight advantage for use as a vascular graft due to presenting greater collagen fiber content.

Key words
Heterografts; Ureter; Collagen; Immunohistochemistry