Introduction: The aim of the present study was to compare the appearance of the normal male puborectalis using transrectal ultrasound with anatomy examinations to enhance the understanding of the relationship of the prostate to the adjacent pelvic floor. This information may help prevent damage to the puborectalis during transperineal ultrasound-guided biopsies and interventional therapies.
Methods: Ten formalin-fixed cadavers were dissected to examine the appearance and structure of the puborectalis and its relationship with the peripheral organs. The puborectalis was also observed in a fresh male cadaver using transrectal ultrasound. In the fresh male cadaver, the puborectalis was located using transrectal sonography, the muscle was confirmed by anatomy, and the thickness was measured.
Results: The ultrasonographic observations of the location of the puborectalis were confirmed by anatomy for the fresh cadaver. Bilateral, symmetrical, hypoechoic strips were observed beside the prostate in cross-section, and strip fibers were observed in the longitudinal section. The right and left puborectalis thickness measurements were 6.1 and 6.2 mm, respectively, in the sonographic image, and the measurements were 5.85 and 5.89 mm, respectively, in the formalin-fixed fresh cadaver.
Conclusions: Transrectal ultrasound provides a new imaging method to observe the male puborectalis, establishing a foundation for recognizing pelvic floor abnormalities with ultrasonography in the future.