**5. Future direction of medical application of bioabsorbable nonwoven fabric spacers**

Adhesions after surgery might lead to serious complications [34, 35]. In the pelvic and abdominal sites, these complications might lead to small-bowel obstruction, infertility, chronic pelvic pain, and difficulty with further surgical access. Therefore, regarding spacer placement, it is necessary to minimize adhesions between the spacer and surrounding organs. In our preclinical study, the efficacy and the safety of a bioabsorbable spacer composed of PGA sutures were investigated in several animal models [19]. The PGA nonwoven fabric spacer exhibited excellent properties, no toxic effects in the animals, and negligible adhesion forma‐ tion. However, different conditions between experimental animals and clinical settings might affect outcomes, and adhesion formation may be different in the presence of malignant tumors.

Therefore, if it is necessary to improve properties of the nonwoven fabric PGA spacer, nextgeneration spacers are expected to avoid adhesion as far as possible. A promising method might be to combine an anti-adhesion material with the PGA spacer. In our recent observation using a healthy rat model, adhesion was significantly decreased, and no exceptional toxicity risk was observed compared with the control group. In the future, less-invasive methods, including endoscopic surgery, might be applied for implantation of the spacer.
