Tissue sealing sheets may improve post-RP function

San Francisco-Erectile function after robot-assisted laparoscopic prostatectomy (RARP) may be better in patients who are treated with fibrin tissue sealing sheets, according to interim results from a randomized controlled trial conducted in Japan.

Investigators reported at the 2018 AUA annual meeting in San Francisco that definitive data with longer follow-up periods are needed to confirm the findings, but they may suggest a useful therapeutic approach to improve erectile dysfunction (ED) after nerve-sparing RARP.

“In the patients who had bilateral nerve-sparing surgery, the recovery rates of erectile function at 12 months after radical prostatectomy were 52% in the sheet group and 40% in the control group,” said lead study investigator Shinichi Yamashita, MD, who is with the Tohoku University Graduate School of Medicine in Sendai.

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Recovery rates for ED following RP remain unsatisfactory, he said, even with nerve-sparing RARP. Recently in Japan, a tissue sealing sheet (TachoSil) has been used to prevent intraoperative bleeding in RP. The product is a collagen sponge that is coated on one side with human coagulation factors fibrinogen and thrombin. Upon contact with blood or other fluids, the coagulation factors react to form a fibrin clot and prevent re-bleeding or effusion, said Dr. Yamashita, who presented the study findings at the meeting.

In the U.S., TachoSil is currently indicated “for use with manual compression in adult and pediatric patients as an adjunct to hemostasis in cardiovascular and hepatic surgery, when control of bleeding by standard surgical techniques (such as suture, ligature or cautery) is ineffective or impractical,” according to manufacturer Baxter Healthcare Corp.

Dr. Yamashita said the team previously found that the tissue sealing sheet attenuated postoperative inflammatory changes and improved erectile function following cavernous nerve dissection in a rat model of nerve-sparing RP.

In the current investigation, the authors examined the efficacy of tissue sealing sheets for erectile function after nerve-sparing RARP in a large group of men. A total of 142 patients with prostate cancer were randomized between January 2014 and March 2017 for nerve-sparing RARP with or without the tissue sealing sheets.

In this study, men with severe ED were excluded. In the treatment arm, the spared neurovascular bundles were covered with the tissue sealing sheets immediately after removal of the prostate. The authors evaluated erectile function preoperatively and at 1-, 3-, 6-, and 12-month periods after RARP using the Expanded Prostate Cancer Index Composite questionnaire.

Dr. Yamashita said 72 men (median age, 65 years) underwent RARP with the tissue sealing sheets. There were 46 men (64%) who had bilateral and 26 men (36%) who had unilateral nerve-sparing procedures in the sheet group. In the control group, 46 men (66%) had bilateral and 24 (34%) had unilateral nerve-sparing procedures. The study demonstrated no significant differences between the groups in operating times and estimated blood loss.

In the sheet group, the recovery rate of erectile function was 14% at 1 month, 20% at 3 months, 31% at 6 months, and 47% at 12 months. That compared to 24% (1 month), 28% (3 months), 31% (6 months), and 36% (12 months) in the control group.

“The recovery rates of erectile function after RARP in the patients with the tissue sealing sheets were better than those without the sheets,” Dr. Yamashita said. “Definitive data with longer follow-up periods are needed to confirm the tissue sealant sheet affects erectile function over time.”

Next: View findings as exploratoryView findings as exploratory

John P. Mulhall, MD, director of the male sexual and reproductive medicine program at Memorial Sloan Kettering Medical Center, New York, said there were six surgeons in this current series and that is something that has to be considered. He said these findings must be viewed as exploratory.

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“The other concerns are that they used a fairly unique scoring system for recovery. They were looking at percentage from baseline score. What they didn’t present and what they need to present in their paper would be the minimally clinically important difference in that score,” Dr. Mulhall told Urology Times. “They are to be congratulated because it is a randomized trial, which is very difficult to do. We look forward to seeing 24-month data.”

Ahmad Majzoub, MD, who attended the presentation, said more research is needed but he expects the product to be widely adopted.

“I believe it is a very sound procedure and a sound technique to do. Using some sort of method or technique to preserve the function of these nerves would definitely help improve outcomes,” said Dr. Majzoub, associate consultant in urology at Hamad Medical Corp., Doha, Qatar.

The study was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science.