Many researched revealed that the mechanism of post-prostatectomy incontinence. There is impairment of various muscles and nerves surrounding the urethral sphincter, rectum and bladder neck. These injuries make a delayed recovery from postoperative incontinence. Therefore, it could be hypothesized that contractile urethral length was a good tool to identify the saving of the muscle and nerve structure surround the urethra. We evaluated the correlation between calculated contractile urethral length using cystography and the duration of postoperative incontinence in patients undergoing radical prostatectomy.

The subjects of this study were 98 men who underwent radical prostatectomy. We measured the urethral movement between relaxing and contracting the pelvic muscle at the time of removing the urethral catheter using cystography (CG). Protocol for radiologic procedures. 10% Diluted contrast media was instilled into the bladder under gravity until a sensation of fullness was reported. Sequencing films were taken every 10 seconds during the procedure to identify Urethro-vesical anastomosis (UVA) leakage. After patients reported a full bladder, an anterior-posterior view and both oblique views of the bladder were obtained. Next, patients were instructed to contract the pelvic muscle, such as when performing a Kegel exercise, to identify the movement of the bladder neck, which was recorded by radiography. After the drainage of contrast media containing fluid from the bladder, a post-drainage view of the bladder was obtained. During the CG, cystography measured bladder neck ascendable vertical length (BNAL) was defined as the vertical length of contrast filled bladder apex between relaxing pelvic muscles and contracting them. If the patient did not effectively contract pelvic muscles in the first trial, after teaching the exercise of contracting pelvic muscle, and then tried to do the second time. The urinary leakage was asked in visiting the office every week until postoperative day 14 and was asked every month until postoperative months 3. And then was asked every 3 months afterward. Recovering urinary incontinence was defined as a pad-free condition for daily living without anxiety.

The median length of the urethral movement during CG was 0.5 cm (range 0–1.5 cm). MEG group revealed parameters such as Number of patients (n=42), Median age (62 ± 5.3 yrs), Median prostate volume (46 ± 17.9cc), Median initial total IPSS (9 ± 2.1), median initial QoL (3 ± 1.2), Median initial Qmax  (15.3 ± 6.7 ml/s), BN opening(%) -Narrow (12.5), Moderate (62.5) and wide (25), NBV saving (54 %), Median length of urethral movement (0.9 ± 0.6 cm) and Mean time to recovery (0.5 ± 0.1 months).
LEG group revealed parameters such as Number of patients (n=56), Median age (69 ± 4.4 yrs), Median prostate volume (44 ± 14.9cc), Median initial total IPSS (14 ± 7.9), median initial QoL (4 ± 1.7), Median initial Qmax  (14.7 ± 5.6 ml/s), BN opening(%) - Moderate (88.2) and wide (11.8), NBV saving (62.5 %), Median length of urethral movement (0.2 ± 0.1 cm) and Mean time to recovery (2.4 ± 1.2 months)

The median length of the urethral movement during CG was 0.5 cm (range 0–1.5 cm). There was no significant correlation between preoperative patient characteristics and duration of urinary incontinence. We used ROC analysis to decide the optimal cut-off value of the urethral movement for predicting postoperative recovery of urinary continence. The cut-off value of 0.6 cm gave the best accuracy in ROC analysis. The area under the ROC curve, sensitivity and specificity were 0.703, 0.583 and 0.863, respectively. 
Patients were classified into two groups according to the length of the urethral movement. There were 29 patients with the urethral movement of 0.6 cm or more in a more elevating group (MEG), and 38 patients with a movement of less than 0.6 cm in a less elevating group (LEG). The median lengths of the urethral movement were 0.2 cm in MEG and 0.9 cm in LEG. Four of the 24 patients in the LEG showed no urethral movement. When we compared the time to recovery of urinary incontinence in both groups, the meantime to the recovery of urinary incontinence in MEG was 0.5 month and in LEG were 2.4 months, respectively. MEG was significantly shorter than LEG. Spearman’s correlation analysis revealed an inverse correlation between the length of the urethral movement and the urinary incontinence volume rate on day 7 after urethral catheter removal (r = -0.488, p < 0.001). There was also a significant difference in recovering the incontinence between two groups until post-operative 10 months.

In this study, we objectively measured the length of the urethral movement. Based on the optimal cut-off value of 0.6cm, the more elevated group showed a fast recovery from postoperative incontinence than the others. In clinical practice, these results can help to estimate the period of restoring the urinary incontinence and describe the prognosis of postoperative incontinence to applicable patients. In conclusion, this study suggests that bladder neck ascending movement on cystogram is significantly associated with early recovery from post-prostatectomy incontinence. This may be easy to proceed and also useful for predicting the course of incontinence. There were a few limitations to this study. We calculated the duration of incontinence using the patient’s memory about sustained urinary incontinence at visiting the clinic.