The location of the neck of the bladder after robot-assisted radical prostatectomy (RARP) correlates with continence rates in patients and could help predict which men are most at risk of prolonged incontinence after surgery.

Research has shown that having a higher bladder neck to pubic symphysis ratio (BNPS)—calculated by dividing the distance between the bladder neck and pubic symphysis by the total height of the pubic symphysis—is associated with an increased probability of incontinence following RARP at both 3 months and 12 months follow-up duration.

Olgin et al. retrospectively assessed 215 patients who underwent RARP and received a postoperative cystogram at a single centre. Information retrieved from the cystogram was used to calculate the BNPS ratios for each patient. At 3 months follow-up duration, 70.7% of patients were continent and these men had a mean BNPS of 0.39, whilst 29.3% were incontinent and these patients had a mean BNPS of 0.49 (P = 0.010). 12 months after surgery, 45 of the 63 men who were incontinent at 3 months had regained continence. These patients had a mean BNPS of 0.44 compared with 0.60 for those who remained incontinent (P = 0.038). For patients with the highest BNPS, the odds ratio for having incontinence was 2.75 (P = 0.008) 3 months after surgery and 8.33 (P = 0.006) after a follow-up duration of 12 months.

These findings suggest that postoperative cystograms and the BNPS ratio could help identify patients at risk of incontinence after RARP, and assist in managing patient expectations and continuing care.