SpaceOAR hydrogel present 32 weeks after instillation prevents neobladder creation in patient undergoing robot-assisted laparoscopic radical cystoprostatectomy

Abstract

Background: The injection of hydrogel in between the anterior rectal wall and prostate protects the rectum from the radiation field in men undergoing radiotherapy for prostate cancer. Multicenter prospective trials have demonstrated safety of the material, and that liquefication and reabsorption of the material occur roughly 12 weeks after injection. Other studies have noted the presence of the hydrogel up to 24 weeks after injection and documented significant complications with its use. In this study we discuss a patient in whom hydrogel was discovered in the anterior rectal wall who was undergoing radical cystoprostatectomy 32 weeks after injection, and how this precluded creation of a neobladder. Case Presentation: A 64-year-old Caucasian man with a history of diabetes mellitus and hypertension was diagnosed with unfavorable intermediate risk prostate cancer. He underwent injection of hydrogel followed by radiotherapy. He subsequently developed hematuria and carcinoma in situ and high grade T1 nonmuscle invasive bladder cancer were diagnosed. Thirty-two weeks later, he underwent robot-assisted radical cystoprostatectomy. The patient was originally planned for neobladder creation but intraoperative findings of persistent hydrogel in between rectum and prostate precluded this reconstruction and necessitated construction of an ileal conduit. Conclusion: Urologists should be aware of the fact that SpaceOAR hydrogel can persist beyond the expected 12- to 24-week dissolution period. In a patient who requires a radical cystectomy, the persistent presence of that gel may preclude the creation of a neobladder. Preoperative imaging to identify persistence vs dissolution of the gel would facilitate better preoperative patient counseling.