Utilization of a Peritoneal Interposition Flap to Prevent Symptomatic Lymphoceles after Robotic Radical Prostatectomy and Bilateral Pelvic Lymph Node Dissection

Introduction: The peritoneal interposition flap (PIF) has been shown to prevent postoperative symptomatic lymphocele (SL) formation after robot-assisted radical prostatectomy (RARP) and pelvic lymph node dissection (PLND). The PIF inhibits the mobilized bladder from resealing over its lateral dissection planes, which overly the lymphadenectomy beds. This creates a window for lymphatic fluid to drain into the peritoneal cavity where it can be absorbed. Herein, we externally validate its utility in preventing postoperative SL formation and assess its effect on postoperative urinary function. Materials and Methods: We retrospectively reviewed all consecutive patients who underwent RARP with bilateral PLND by a single surgeon between July 2016 and September 2019. All patients who underwent surgery before August 8, 2018 did not receive the PIF, while those who underwent surgery after August 8, 2018 received the PIF. Our PIF technique involves fixing the peritoneum overlying the lateral dome of the bladder to the ipsilateral, anterior-lateral surface of the bladder using a barbed absorbable suture. Continuous and categorical variables were compared between the two groups using independent t-tests and chi-square tests, respectively; p < 0.05 was considered significant. Results: Of 318 total patients, 201 did not undergo the PIF and 117 underwent the PIF. With regard to postoperative complications, patients undergoing the PIF had a lower incidence of SL compared with those not undergoing the PIF (0.0% vs 6.0%, p = 0.007). There was no difference in 30-day postoperative nonlymphocele complications (Clavien >2) between both groups (p = 0.800). With regard to urinary function, there was no difference in the rate of 3-month postoperative continence (p = 0.624), preoperative American Urological Association Symptom Score (AUASS) (p = 0.898), and postoperative AUASS (p = 0.470) between both groups. Conclusion: Utilization of a PIF may minimize the risk of SL formation after RARP and PLND without increasing the risk of non-SL-related complications. This technique does not adversely affect postoperative urinary function.