Peritoneal Flap in Robot-Assisted Radical Prostatectomy

Background: Lymphocele is the most common complication arising after pelvic lymph node dissection (PLND) in the setting of robot-assisted radical prostatectomy (RARP). The only data available until now on the utility of a peritoneal flap to prevent lymphocele were retrospectively acquired. Methods: A randomized, controlled, multi-center trial with blinded assessment of endpoints was carried out on 232 patients with prostate cancer who underwent RARP with PLND. The patients in the intervention group were given a peritoneal flap; in the control group, surgery was performed without this modification. The two joint primary endpoints were the rates of symptomatic lymphocele during the same hospitalization as the operative procedure (iT1) and within 90 days of surgery (iT2). The secondary endpoints were lymphocele volume, the need for treatment of lymphocele, complications requiring an intervention, and the degree of postoperative stress incontinence. German Clinical Trials Register number: DRKS00011115. Results: The data were evaluated in an intention-to-treat analysis, which, in this trial, was identical to an as-treated analysis. 108 patients (46.6%) were allotted to the intervention group. There were no statistically significant intergroup differences with respect to any clinical or histopathological criteria. A median of 16 lymph nodes were removed (interquartile range, 11-21). A symptomatic lymphocele arose in 1.3% (iT1) and 9.1% (iT2) of the patients, without any statistically significant difference between the two trial groups (p = 0.599 and p = 0.820, respectively). Nor did the groups differ significantly with respect to lymphocele volume (p = 0.670 on hospital discharge [T1], p = 0.650 90 days after surgery [T2]) or the type and frequency of need for subsequent surgical intervention (p = 0.535; iT2). 81.5% of all patients (n = 189) had no complications at all in the first three months after surgery. Nor were there any intergroup differences at 90 days with respect to the degree of stress urinary incontinence (p = 0.306) or complications (p = 0.486). Conclusion: A peritoneal flap after RARP was not found to influence the rate of postoperative lymphocele, whether asymptomatic or requiring treatment.