Urinary catheterization of male rabbits: a new technique and a review of urogenital anatomy

Abstract

Rabbits are widely used as an animal model for urologic research studies in which urinary bladder catheterization is required. However, standard manual retrograde urinary catheterization proved to be difficult to perform on anesthetized male rabbits in a research study, with frequent misplacement of the catheter into the vesicular gland. Attempts to reposition the catheter into the bladder after initial entry into the vesicular gland frequently failed and resulted in exclusion of the animal from the study. We assessed the normal anatomy of the lower urinary tract of male rabbits to determine the cause of catheterization misdirection into the vesicular gland and to develop a more reliable technique for urinary bladder catheterization. A modified 'digital (finger) pressure' catheterization technique was developed for successful urinary catheterization of male rabbits. Retrospective statistical analysis of 45 rabbits used for urinary catheterization studies showed improvement in the success rate of catheterization by using the digital pressure technique over the standard method of retrograde urinary catheter insertion. In addition, we here review the relevant gross and histologic anatomy of the urogenital tract of male rabbits.

Figure 1.

Schematic demonstration of the digital (finger) pressure technique of urinary catheterization of male rabbits. Arrows indicate the point of pressure application. (A) Lateral view. (B) Ventral view.

Figure 2.

CT images demonstrating misplacement of the catheter into the VG and corrected placement by using digital pressure technique. (A) Axial CT section showing the position of the urethra under the pubic symphysis (arrow). (B) Sagittal section demonstrating misplacement of the catheter tip into the VG (arrow). (C) Sagittal and (D) coronal images demonstrating correct placement of the catheter tip within the urinary bladder of the same rabbit by using digital pressure technique (arrows).

Figure 3.

Photographs of male rabbit urogenital tract. (A) Lateral view. (B) Dorsal view. Anatomic structures: a, urinary bladder; b, vesicular gland; c, proprostate; d, prostate; e, paraprostate; f, bulbourethral gland; g, urethra; h, deferent duct.

Figure 4.

(A) Urethra, colliculus seminalis, and the neck of urinary bladder. (B) Misplacement of catheter into the Vesicular gland. a, urethral lumen; b, colliculus seminalis and opening of ejaculator duct; c, the neck of urinary bladder; d, catheter.

Figure 5.

(A) Vesicular gland. a, mucosa with glands; b, submucosa; c, tunica muscularis; d, adventitia. (B) Vesicular gland near the ejaculator duct. a, mucosal epithelium; b, thick wall of loose connective tissue with bundles of smooth muscle fibers. Hematoxylin and eosin stain. Magnification, 200×.