An enlarged median lobe (ML) presents a technical challenge during robotic prostatectomy (RP) and its potential effects on outcomes are not well known. If known, the impact of a potentially larger bladder neck on continence as well as the impact of preoperative chronic outlet obstruction on postoperative urinary symptoms might aid in patient counseling. We assessed the impact of intraoperatively identified median lobes (ML) on urinary function.

We reviewed our prospective database of 1899 RPs performed between July 2013- July 2019. International Prostate Symptoms Scores (I-PSS) were assessed preoperatively and at one, three, and six months postoperatively. In addition, a functional urinary survey was obtained regarding postoperative frequency, nocturia, urgency and continence at the same time points. Continence was defined as the use of 0-1 pads daily. We compared patients with ML and without ML (NoML). Bladder-neck sparing was routinely performed to avoid reconstructions regardless of ML whenever possible.

Of 663 patients who completed I-PSS at all time points, 202 (30%) had ML. There were no significant differences in demographics, PSA or clinical stage between ML and NoML patients. Only two ML and one NoML patients required bladder neck reconstruction. There was no immediate or long-term difference in continence rates between groups (Figure 1). Baseline mean I-PSS was higher in ML patients and showed more improvement 6 months postoperatively (-5.5 versus -3.6, p<0.05) (Figure 2). Voiding symptoms significantly decreased in both groups at all time points. However, mean sub-score for storage symptoms (items 2, 4 and 7 of I-PSS) was higher in NoML patients with mild symptoms (I-PSS 1-7) at each postoperative time point. Mean pre-operative frequency was higher in the ML group (6.9 episodes/24hs versus 7.6 episodes/24hs, p= 0.02) rising to 8.2 episodes/24hs in ML and 8.8 episodes/24hs in No ML group at one month postoperatively (p=0.07). The rate of patients with urgency decreased 5% in ML and 6% in NoML at 6 months following RP. Differences in I-PSS between groups resolved by 6 months postoperatively (6 vs 6.5, p=0.638).  Overall, there were no correlations between prostate volume and I-PSS at any postoperative time point.

Patients with ML appear to benefit more in terms of postoperative urinary function initially. RP has higher impact on voiding rather than storage symptoms in both groups. Prostate volume was not related to symptom severity.

ML enlargement does not have an increased risk of incontinence and has only a short-term effect on urinary function after RP.