Robot-Assisted Radical Prostatectomy (RARP) represents the principal cause of male stress Urinary Incontinence (UI), but a post-operative non-invasive and objective test is still lacking (1). The principal pathophysiologic mechanism underlying UI is urethral closure pressure lower than the bladder one, therefore implying the pathological inability to retain urine. However the surgically-induced modifications on the continence mechanisms is still not completely understood, particularly in the neuro-urological relationship between internal and external sphincteric system (2). Considering the neuro-vascular support to the interdependent striated and smooth muscles of pelvic floor system, we recently proposed Uroflow Stop Test (UST) with surface Electromyography (EMG) (3). 
Aims: We provided two new clinical parameters: the Neurologic Latency Time (NLT) and the Urologic Latency Time (ULT) by analyzing the beginning of EMG signal activation during UST-EMG test. Principal outcome was to evaluate their variation during one year follow-up, and ULT ability in predicting UI.

We conduct a prospective observational study in a high-volume tertiary care institute starting from January 2018 until January 2020 on patients with clinically localized Prostate Cancer (PCa) underwent full nerve sparing RARP. 60 patients were enrolled. We obtained written informed consent from every participant before enrollment and surgery. 
All patients performed PFMT within the first and the third month after surgery. The PFMT program was organized in two parts: a hospital and a home program. Every patient received a pelvic floor exercise leaflet, in which was encouraged to perform three times a day these exercises at home: elevation of the hip, then relaxing muscles while lowering  and PFMs contraction as previously reported, during inspiration and expiration, respectively.
In the hospital PFMT program, leaded by physicians, the patients was invited to attend eight one-to-one sessions held by the same continence- specialized urology nurse over two months. A combination of different types of exercises including PFMs contraction – targeting both slow and fast-twitch muscle fibers - coupled with the subjective feeling of squeezing and lifting of the muscular-fascial planes of the pelvic area. We use an internal anal biofeedback, and patient was instructed to graphically display PFMs performances. 
They completed two questionnaire at 1-, 3-, 6- and 12-months after surgery: 5-item of the EPIC-26 questionnaireand the International Consultation on Incontinence Questionnaire-Urinary Incontinence short form (ICIQ-UI Short Form), comprising a question about everyday QoL [15].
The Kruskal-Wallis One Way Analysis was used at each visit to investigate if and how these parameters differed between continent and incontinent patients. Finally, to evaluate the diagnostic ability of 1-month post-surgery ULT to diagnose the presence of post-operative urinary incontinence, we examined the Area Under Curve (AUC) together with the optimal cut-off values were computed. We set a p-value of 0.05 both intra- and inter-group.

The mean time to PFMT was 31.08 (range: 30-35) days. Overall IPSS, NLT and ULT had similar trends: progressive decrease until the six month after surgery to plateau thereafter. When considering the two group of patients, IPSS and NLT were significantly higher in the incontinent group only one month after surgery, while ULT became similar between the two groups 6 months after surgery (Figure 1). The best cut-off of 1-month ULT values that maximized the Youden function at 12-months resulted 3.13 second (Figure 2).

In our cohort of patients, ULT was more informative than NLT, this remaining within the pre-surgical values, in spite of the statistical significance, which could be justified by our full-nerve sparing technique. When the coohort was split according to UI, an interesting behaviour occurred. We provide the first post-operative urological evaluation at 1 month to spare clinical disturbing elements, immediately after catheter removal. After 3 months, the ULT still remained higher, while the NLT did not. The improvement of ULT stopped within six months, therefore  confirming the recovery from the neuropraxia to aid UI recovery.

We have introduced for the first time two new specific parameters that may account for the nerve integrity and for the urethral closure system. We have shown, that only in the first month after surgery incontinency was associated to deficit in both neurological and urological times, while the urologic time kept its discriminatory role for the whole first trimester after surgery, therefore confirming the recovery from neuropraxia to aid UI recovery.
The easy application of our test may help to monitor the post-operative continence recovery . ULT may help rehabilitation specialists in evaluate the ongoing results of PFMs rehabilitation after RARP.

Alesha Sayner, Irmina Nahon, Pelvic Floor Muscle Training in Radical Prostatectomy and Recent Understanding of the Male Continence Mechanism: A Review, Seminars in Oncology Nursing,  Volume 36, Issue 4, 2020,
Hunter KF, Moore KN, Glazener CMA. Conservative management for postprostatectomy urinary incontinence. Cochrane database Syst Rev 2007; 2: CD001843
Boni A, Cochetti G, Del Zingaro M, Paladini A, Turco M, Rossi de Vermandois JA, Mearini E: Uroflow stop test with electromyography: a novel index of urinary continence recovery after RARP. International urology and nephrology 2019.