Transperineal ultrasound evaluation of pelvic floor muscle function in male patients with constipation.

Objective: To investigate the application of transperineal ultrasound for assessing pelvic floor muscle (PFM) function in male patients with constipation and to evaluate its clinical value.

Methods: The study included 32 male patients with constipation and 32 healthy controls, all of whom underwent transperineal ultrasound examinations. Measured parameters included the anorectal angle (ARA), levator plate angle (LPA), excursions of the ARA and LPA, and displacements of the bulb of the penis (BP), mid-urethra (MU), urethra-vesical junction (UVJ), and anorectal junction (ARJ) at rest, during maximal voluntary contraction (MVC), and during maximal Valsalva maneuver. Reliability was evaluated in 20 healthy controls using intraclass correlation coefficients (ICCs) and Bland-Altman analysis.

Results: (1) The ICCs for each parameter measured by both the same and different observers were above 0.84, indicating high repeatability. At least 90% of the measurements by the same and different observers fell within the 95% confidence interval (CI). (2) At rest, the ARA in patients with constipation was significantly larger than in healthy men (P < 0.05). During MVC, LPA, the ARA excursion, LPA excursion, BP displacement, UVJ displacement, and ARJ displacement in constipation patients were also significantly larger than in healthy men (P < 0.05). Furthermore, BP displacement, UVJ displacement, and ARA excursion during maximal Valsalva maneuver in constipation patients were significantly larger than in healthy men (P < 0.05). (3) Receiver operating characteristic curve analysis revealed that the following indicators demonstrated area under the curve (AUC) values exceeding 0.75: ARA excursion of MVC, ARA excursion of maximal Valsalva maneuver, resting ARA, and ARJ displacement of MVC, with AUC values of 0.782, 0.778, 0.770, and 0.765, respectively. No significant differences in diagnostic performance were found among these indicators (P > 0.05).

Conclusion:  Transperineal ultrasound is a reliable and practical technique for assessing the morphology and function of male PFMs. Parameters such as ARA excursion during MVC, ARA excursion during maximal Valsalva maneuver, resting ARA, and ARJ displacement during MVC are valuable for diagnosing PFM dysfunction in constipated patients.