Safety of Hydrogel Spacers for Rectal Wall Protection in Patients with Prostate Cancer: A Retrospective Analysis of 200 Consecutive Cases

Objective To evaluate the safety and complications of hydrogel spacer implantation. Methods This single‐center historical cohort study retrospectively analyzed cases of hydrogel spacer implantation between October 2018 and March 2022. The survey items were the rates of possible hydrogel injection implementation, the success rate of hydrogel implantation including asymmetry, higher position, rectal wall infiltration, subcapsular injection, and other adverse events, and width created by the spacer. To investigate the learning curve, 1, 2, and 3 points were assigned to adverse event grades G1, G2, and G3, respectively. Spacer effectiveness obstruction, such as asymmetry was assigned 3 points. A Mann–Whitney U test was performed to assess statistically significant differences. Results The study included a total of 200 patients with a median (range) age of 70 (44–85) years. In 10 (5%) patients, hydrogel injection implementation was not possible. Of 190 patients who underwent hydrogel spacer placement, 168 (88%) received a satisfactory placement. The median (range) width of hydrogel spacers was 13.1 (4.4–18.7) mm. Spacer asymmetry, higher position, rectal wall infiltration, and prostate subcapsular infiltration occurred in 7 (3.7%), 5 (2.6%), 12 (6.3%), and 1 (0.5%) patients, respectively. G1 and G3 adverse events occurred in 13 (7%) and 4 (2%) patients, respectively. Practitioner #1 who performed the highest number of procedures had significantly ( p = 0.04) lower total scores in group B. Conclusion Spacer implantation yielded favorable outcomes with a high percentage of appropriate spacer implantation, and few major complications.