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Updated: Oct 2, 2025
A Novel Surgical Technique in a Sheep Model for Suburethral Graft Implantation
Published on: June 20, 2025
Comparison of Morphological and Histological Characteristics of Human and Sheep: Sheep as a Potential Model for
Ilaha Isali1, Ahmad Osama Khalifa2, Subba Shankar3
1Department of Urology, Case Western Reserve University, Cleveland, Ohio, USA, ixi22@case.edu.
Introduction:
The sheep was evaluated as a potential model for preclinical evaluation of urethral slings in vivo based on: (1) anatomical measurements of the sheep vagina and (2) histological tissue integration and host response to polypropylene (PP) slings.
Methods:
Eight female, multiparous sheep were utilized. Three of 8 animals underwent surgery mimicking human tension-free vaginal tape protocols for midurethral slings and were euthanized at 6 months. The following measurements were obtained: vaginal length, maximum vaginal width with retraction, symphysis pubis length, and distance from the pubic bone to incision. Explanted sling samples from sheep and human were stained with hematoxylin and eosin for host reaction assessment.
Results:
Geometric measurements were similar between humans and sheep. Sheep vaginal anatomy allowed sling placement similar to procedures in human surgeries, and all sheep recovered without problems. Comparative histology between the sheep and human indicated similar host reaction and collagen deposition around implants, confirming suitability of the sheep model for biomaterial response assessment.
Conclusion:
Sheep vaginal length is comparable to humans. Tissue integration and host response to PP slings showed chronic inflammation with rich collagen deposition around the material in both sheep and human specimens, highlighting the sheep as a potential animal model for preclinical testing of midurethral slings.
