Investigating The Mechanism Underlying Urinary Continence Using Dynamic-MRI After Retzius-sparing Robot-assisted Radical Prostatectomy

Retzius-sparing robot-assisted radical prostatectomy (RS-RARP) has been reported to exhibit better postoperative urinary continence compared to conventional RARP (C-RARP) via the anterior approach, but the reasons behind this are unknown. The early postoperative urinary incontinence and anatomical differences were compared between 51 cases each of C-RARP and RS-RARP, which were selected via propensity score matching. Dynamic-MRI was performed before and after surgery to investigate the pelvic anatomical changes under abdominal pressure. The median urine loss ratio in the early postoperative period was 11.0% and 1.0% for C-RARP and RS-RARP, respectively. Postoperative MRI revealed the anterior bladder wall after RS-RARP was fixed in a high position compared to C-RARP. Dynamic-MRI after C-RARP showed cephalocaudal compression of the bladder during abdominal pressure caused expansion of the membranous urethra and the urine flowed out. In RS-RARP cases, the rectum moved forward during abdominal pressure to compress the membranous urethra by closing it from behind, as was observed preoperatively. This was the first study using dynamic-MRI which revealed the importance of a high attachment of the anterior bladder wall for the urethral closure mechanism during abdominal pressure. RS-RARP, which can completely preserve this mechanism, was the least likely to cause stress urinary incontinence.

Transperineal ultrasound as a reliable tool in the assessment of membranous urethra length in radical prostatectomy patients

To evaluate the usefulness of transperineal ultrasound (TPUS) as a method of membranous urethra length (MUL) measurement and investigate whether preoperative (MULpre) and postoperative (MULpost) would be associated with the degree and time of urinary continence recovery after laparoscopic radical prostatectomy (LRP). 84 patients who underwent LRP between January 2017 and December 2018 were selected for final analysis. All patients had preoperative and postoperative measurement of MUL in TPUS. Urinary continence was defined as no pad or a safety pad. Recovery of continence was assessed at 1, 3, 6 and 12 months after catheter removal. We prospectively analyzed correlation of MULpre, MULpost and a percent change in membranous urethral length (MULratio) with the urinary continence status. 69 (82%) patients regained continence in the follow-up of 12 months. MULpre, MULpost and MULratio assessed in TPUS were larger in subgroups of patients who regained continence earlier and in the entire continent group. Spearman rank test showed strong correlations between MULpost and MULratio (R—0.6 and R—0.56, respectively, p < 0.0001) with the time to continence recovery in the cumulative 12 months follow-up. TPUS allowed a reliable measurement of MUL before and after LRP. MULpre, MULpost as well as MULratio are related with time to regain continence and recovery rate after LRP. Sparing longest possible sphincteric urethra, with respect to oncological outcomes is a key factor in recovering continence after prostate cancer surgery.

Chlamydia pecorum Infection in the Male Reproductive System of Koalas (Phascolarctos cinereus)

Chlamydiosis is the most documented and serious disease of koalas, characterized by ocular, urinary, and reproductive lesions. Since little attention has been paid to the pathological effects of this infection in the male reproductive system, we aimed to determine the incidence and severity of reproductive pathology associated with chlamydial infection in male koalas submitted to koala hospitals in southeast Queensland. The entire reproductive tract from 62 sexually mature male koalas not suitable for rehabilitation was evaluated and 677 tissue samples were collected for histology, immunohistochemistry (IHC), and real-time polymerase chain reaction (qPCR). Lymphoplasmacytic inflammation was observed in 178 of 677 (26.3%) tissue samples from the upper and lower reproductive tract, mainly in the prostatic, penile, and membranous urethra. IHC was positive for the chlamydial antigen in 19 of 451 normal samples (4.2%) and 46 of 178 samples with inflammation (25.8%), located within the cytoplasm of epithelial cells of the epididymis, vas deferens, prostate, bulbourethral glands, and the prostatic membranous and penile urethra. Chlamydia pecorum was detected via qPCR in 319 of 451 normal samples (70.7%) and 159 of 178 samples with inflammation (89.3%), with the highest incidence in the penile urethra, prostate, membranous urethra, and bulbourethral glands. This study suggests that Chlamydia infection in the male reproductive tract is more widespread than originally thought. Furthermore, the male reproductive tract might be a reservoir for persistent chlamydial infections in koalas, with important implications for prophylactic strategies and epidemiology.

MODERN METHODS OF TREATING DISEASES OF THE BULBO-MEMBRANOUS PART OF URETHRA

Strictures of the bulbous-membranous urethra are a common cause of obstructive urination disorder. Modern trends in the development of medicine lead to a wider application of endoscopic method, a more frequent cause of iatrogenic injury of the urethra. At present, conservative, endourologic and reconstructive methods of care are used to treat urethral strictures. There are several conservative, endourological and reconstructive methods for treating patients with urethral stricture. Conservative methods include interventions that do not involve the destruction of urethral stricture or its reconstruction, such as stenting, blind dilatation, and recanalization of the urethra. Performing blind dilatation strictures of the bulbo-membranous urethra is not recommended because of the high risk of false path formation and low efficiency. Endourological operations refer to surgical methods of care and suggest the natural restoration of urethral tissues after the destruction of stricture. Because of the low effectiveness of correction of strictures of the posterior urethra (more than 90 % of relapses in five years), this method is a variant of temporary or palliative care. Currently, two approaches to the reconstruction of the bulbo-membranous urethra are used: anastomotic and replacement operations. Anastomotic surgery involves excision of the affected area and juxtaposition of healthy urethral tissues without tension. Replacement plastic allows to restore patency of the urethra by increasing the diameter of the lumen due to the implantation of various grafts. The article shows that, based on international clinical studies, the most effective method of reconstructing the bulbomembranous urethra is reconstructive surgical methods.

The Structure of Urethral Epithelium in Merinos Lambs

The aim of this study was to investigate by histological techniques the structure of urethral epithelium in lambs. In this study, we harvested several fragments (prostatic, membranous and cavernous) from urethra from 5 merino’s lambs of 3 months old. The first anatomical segment, the prostatic urethra, is lined by a urinary epithelium. The intermediary layer of this epithelium is formed of 5-6 rows of oval cells. The second segment of urethra has the same type of epithelium but the intermediary layer is formed of 6-7 rows of oval cells. In the last anatomical segment, the penile urethra, the epithelium is the same, but the intermediary layer has 3-4 rows of oval cells. In lambs, the urethra is lined by urinary epithelium. The urethral epithelium does not have the same thickness in all segments. The thinner epithelium it is in the cavernous urethra, the ticker is the membranous urethra.