HIBISCUS trial (hernia incidence with continuous barbed vs interrupted suturing in colorectal surgery with small incisions): a contemporary study protocol for a multicenter randomized controlled trial.

[BACKGROUND] Incisional hernia is the most common long-term complication after abdominal surgery, including minimally invasive colorectal procedures. In Japan, fascial closure of small midline incisions is generally performed using interrupted suturing, but high-quality evidence comparing continuous barbed suturing with interrupted suturing is limited. Continuous closure may reduce the risk of incisional hernia; however, robust randomized data in laparoscopic and robot-assisted colorectal surgery are lacking. This study aims to determine whether continuous barbed suturing is superior to conventional interrupted suturing in preventing incisional hernia after minimally invasive colorectal cancer surgery.

[METHODS] The HIBISCUS trial is a multicenter, prospective, open-label, randomized controlled study comparing continuous barbed suturing with interrupted monofilament suturing for fascial closure of mini-laparotomy incisions. Eligible adults with colorectal cancer undergoing elective laparoscopic or robot-assisted resection will be randomized 1:1 to continuous closure using a barbed absorbable suture (STRATAFIX Symmetric PDS Plus; bite width of 5 mm and stitch spacing of 5 mm) or interrupted closure using a monofilament absorbable suture (PDS Plus; bite width of 8 mm and stitch spacing of 8 mm). Only board-certified surgeons who complete a standardized pre-trial suturing competency assessment will be allowed to participate. The primary endpoint is the incidence of incisional hernia within 18 months after surgery, assessed mainly by scheduled abdominal CT imaging, with clinical examination as complementary. Secondary endpoints include fascial closure time, postoperative wound complications (including surgical site infection (SSI)), postoperative wound pain, and reoperation or readmission. All CT images will be independently reviewed by two blinded specialists. Based on power calculations, 422 patients will be enrolled.

[DISCUSSION] This trial will be the first randomized study to directly compare continuous barbed suturing with conventional interrupted suturing for small midline incisions in minimally invasive colorectal surgery. By standardizing suturing parameters and requiring surgeon competency verification, the HIBISCUS trial is designed to yield high-quality evidence on optimal fascial closure technique. The results are expected to influence clinical practice, inform guideline development, and contribute to the global standardization of abdominal wall closure practices.

[TRIAL REGISTRATION] This study is registered in the Japan Registry of Clinical Trials (jRCT1040250129). Registration date: November 21, 2025.