Seminal vesicle sparing radical cystectomy (SVS-RC) has been reported to improve short-term functional results without compromising oncological outcomes. Several series on short- to mid-term oncological and functional outcomes of sexual function–preserving cystectomy (SPC) were published in the past, showing better sexual outcomes without compromising oncological outcomes. However, the quality of evidence remains low-to-moderate and long-term data is still lacking(1,2). 
The aim of this study was to compare oncological and functional outcomes in patients after SVS vs non-SVS RC.

Oncological and functional outcomes of 470 consecutive patients after RC and orthotopic ileal reservoir, from 2000 to 2017, were evaluated. They were stratified into six groups according to nerve-sparing (NS) and SVS status as attempted during surgery: no sparing at all (n=55), unilateral NS (n=159), bilateral NS (n=132), unilateral SVS and unilateral NS (n=30), unilateral SVS and bilateral NS (n=45), and bilateral SVS (n=49), and used propensity modelling to adjust for preoperative differences. Urinary continence (UC) and erectile function recovery (EFR) were assessed preoperatively and at each follow-up visit using previously published standardised questionnaires and since 2004 with the ICIQ-UI-SF and IIEF-15 questionnaires(3).

Median follow-up among the entire cohort was 64 months. Among the six groups, our analysis showed no difference in local recurrence-free survival (p=0.173). However, progression free, cancer specific and overall survival were more favourable in patients with SVS RC (p<0.001, p=0.006 and p<0.001, respectively). Propensity scores showed good overlap in all treatment group comparisons before and after IPTW, standardized differences of pre-operative variables were below 0.1, except tumour stage and lymph node metastasis in the comparison of bilateral NS vs bilateral SVS, which was 0.165 and 0.115, respectively, indicating no meaningful differences between treatment groups. 
Our primary functional outcome was EFR in the time period from three months to five years after surgery. After IPTW, proportions of patients with EFR were higher in the SVS groups at all time points in all analyses, respectively, with pronounced earlier recovery in patients with bilateral SVS. Accumulated for the whole period this corresponds to a higher proportion of patients with EFR, OR 12.3 (95% CI 5.74 to 26.2, p<0.001) for SVS vs no-SVS, 16.8 (3.28 to 85.6, p=0.001) for bilateral SVS vs bilateral NS and 8.60 (3.68 to 20.1, p<0.001) for unilateral SVS vs unilateral NS. Importantly, patients with SVS were significantly less in need of erectile aid (PDE5 inhibitors, Alprostadil by use of MUSE or auto-injection therapy) to achieve erection and intercourse, respectively. 
Similar but less pronounced differences were seen with respect to proportions of patients with the ability for erection, in all comparisons at every time point, except for bilateral NS vs bilateral SVS three months after surgery. Erections sufficient for intercourse were more frequent in the SVS groups with an overall OR of 6.75 to 9.78 indicating that less invasive support was needed to achieve the ability of intercourse after SVS vs no-SVS.
Daytime UC was in general high from six months postoperatively onwards with slightly higher proportions in patients after SVS at every single time-point, except for bilateral NS vs bilateral SVS, where proportions were basically the same from one year on. Over the whole period, daytime UC was significantly better in the SVS groups (OR 2.64 to 5.21). With respect to night-time UC, found higher proportions after SVS in all comparisons, which did not reach statistical significance for unilateral NS vs unilateral SVS.

Our analysis yielded several important findings. Most importantly, oncological outcomes were not inferior in all degrees of SVS. Secondly, we found an earlier recovery of UC in patients with SVS compared to NS only. Likewise, SVS has a beneficial impact on early EFR which remains significantly better over a longer period of time. Having conducted a propensity score weighting, the estimation of the effect of SVS on functional and oncological outcomes is even more valid.  However, patients have to fulfill certain inclusion criteria to be considered for SVS. Therefore, a general applicability of these findings to all patients undergoing RC for bladder cancer is not possible. Hence, we believe that this technique, a careful patient selection provided, constitutes no compromise of oncological principles, even in the case of unexpected limited invasion of the urothelial carcinoma into the prostate.

In a highly selective group of patients, seminal vesicle sparing radical cystectomy is oncologically safe and results in excellent functional outcomes that are reached at an earlier timepoint after surgery and remain superior over a longer period of time.

Hernandez, V., Espinos, E. L., Dunn, J. et al.: Oncological and functional outcomes of sexual function-preserving cystectomy compared with standard radical cystectomy in men: A systematic review. Urol Oncol, 35: 539.e17, 2017.
Basiri, A., Pakmanesh, H., Tabibi, A. et al.: Overall survival and functional results of prostate-sparing cystectomy: a matched case-control study. Urol J, 9: 678, 2012.
Klovning, A., Avery, K., Sandvik, H. et al.: Comparison of two questionnaires for assessing the severity of urinary incontinence: The ICIQ-UI SF versus the incontinence severity index. Neurourol Urodyn, 28: 411, 2009.