Hypothesis / aims of study
Few studies have focused on details of quality of life (QOL) after robot-assisted radical prostatectomy (RARP). Nerve-sparing (NS) radical prostatectomy reportedly contributes not only to the recovery of erectile function but also to improvement of urinary incontinence [1, 2]. However, there is a relative paucity of data on the impact of the NS procedure on lower urinary tract symptoms (LUTS) except for urinary incontinence, especially in the context of RARP. The present study aimed to investigate the impact of RARP on QOL and of the NS procedure on erectile function and LUTS, including urinary incontinence, after RARP.
Study design, materials and methods
A prospective, clinical cohort, observational study was conducted on 306 consecutive patients who underwent RARP at our institution between October 2010 and June 2016. NS techniques were performed according to the four grades of posterolateral prostatic resection: grade 1, intrafascial; grade 2, interfascial; grade 3, extrafascial; and grade 4, wide dissection. NS was defined as NS grade 1 or 2, partial NS was defined as NS grade 3, and non-NS was defined as NS grade 4. The Medical Outcomes Study 8-Item Short Form (SF-8), Expanded Prostate Cancer Index Composite (EPIC), International Prostate Symptom Score (IPSS), IPSS subscore including voiding and storage, Overactive Bladder Symptom Score (OABSS), and urinary incontinence were assessed preoperatively (2 days before RARP) and at 1, 3, 6, 9, 12, 18, and 24 months postoperatively. Postoperative urinary incontinence was assessed at scheduled visits 1, 3, 6, 9, 12, 18, and 24 months after RARP. Patients who used no pads were considered to be urinary continent, and those who used ≥1 security liner pads per day were considered to be urinary incontinent. Postoperative recovery of erectile function was defined as an EPIC-Question 18 score of ≥2 in patients with a preoperative EPIC-Question 18 score of ≥2.
Median age at surgery was 65 (range, 48–76) years, and median prostate volume was 29.0 mL (range, 10–109.2). At 1 month postoperatively, all scores were found to have decreased significantly (Fig. 1). However, bodily pain, general health, vitality, role emotional, mental health (MH), and mental component summary (MCS) scores improved within 3 months. Moreover, physical functioning (PF), social functioning (SF), and physical component summary scores improved within 6 months. In the incontinence groups, PF, role physical (RP), MH, and MCS scores were significantly lower than those in the continence group at 24 months postoperatively. Across the five NS groups, as the procedure became more nerve-sparing, the recovery rate of erection became significantly higher. Postoperative effects on erection in the bilateral and unilateral NS groups were significantly superior to those in the other NS groups. A strong association was found between the degree of neurovascular plate preservation and urinary continence. The NS procedure did not affect improvement of the IPSS total score, IPSS voiding subscore, IPSS storage subscore, and OABSS total score after RARP (Fig. 2).
Interpretation of results
A recent review showed that when performing non-NS surgeries, somatic and autonomic nerves are at risk of damage due to wide excision at the level of the seminal vesicles or the periprostatic dissection or at the level of the apex, where convergence occurs and the nerves are within a few millimeters of the dissection plane and suture bites . The somatic and autonomic nerves travel within the layers of the fascia of the levator ani and could sustain injury if the resection plane is sufficiently wide. Therefore, the NS procedure may lead to early improvement of urinary incontinence after RARP.
The health-related QOL (HRQOL) decreased immediately after RARP, but improved to preoperative levels within a few months. Postoperative urinary continence appears to have a favorable effect on health-related QOL following RARP, especially for the mental component. The NS procedure contributes not only to recovery of erectile function but also to improvement of urinary incontinence, even though the NS procedure in RARP did not ameliorate LUTS except for urinary incontinence. Therefore, if possible, the NS procedure is recommended from the viewpoint of early improvement of urinary incontinence after RARP.