Effect of Daikenchuto (TJ-100) on gastrointestinal symptoms following laparoscopic colectomy in patients with colon cancer: study protocol for a randomized controlled trial

BACKGROUND: Postoperative paralytic ileus can be a difficult complication for both surgeons and patients. Causes and treatments have been discussed for more than two centuries, but have not yet been fully resolved. Daikenchuto (TJ-100, DKT) is a traditional Japanese herbal medicine. Recently, some beneficial mechanisms of DKT to relieve paralytic ileus have been reported. DKT can suppress inflammation, increase intestinal blood flow, and accelerate bowel movements. Therefore, we have designed a randomized controlled trial to investigate the effects of DKT on postoperative gastrointestinal symptoms following laparoscopic colectomy in patients with left-sided colon cancer at a single institution. METHODS/DESIGN: As primary endpoints, the following outcomes will be evaluated: (i) grade of abdominal pain determined using the numeric rating scale (NRS), (ii) grade of abdominal distention determined using the NRS, and (iii) quality of life determined using the Gastrointestinal Quality Life Index (GIQLI). As secondary endpoints, the following will be evaluated: (i) postoperative nutritional status (Onodera’s Prognostic Nutritional Index (PNI) and the Controlling Nutritional Status score (CONUT score)), (ii) duration to initial flatus, (iii) duration to initial defecation, (iv) bowel gas volume, (v) character of stool (Bristol Stool Form Scale), (vi) defecation frequency per day, (vii) postoperative complications (Clavien-Dindo classification), (viii) length of postoperative hospital stay, and (ix) metabolites in the stool and blood. This trial is an open-label study, and needs to include 40 patients (20 patients per group) and is expected to span 2 years. DISCUSSION: To our knowledge, this is the first randomized controlled trial to investigate the effects of DKT on postoperative subjective outcomes (i.e., postoperative quality of life) following laparoscopic colectomy as primary endpoints. Exploratory metabolomics analysis of metabolites in stool and blood will be conducted in this trial, which previously has only been performed in a few human studies. The study aims to guide a future full-scale pragmatic randomized trial to assess the overall effectiveness of DKT to improve the postoperative quality of life following laparoscopic colectomy. TRIAL REGISTRATION: UMIN-CTR (Japan), UMIN000023318. Registered on 25 July 2016. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13063-017-2307-7) contains supplementary material, which is available to authorized users.