In 2024, the second edition of the Japan Society of Coloproctology (JSCP) Practice Guidelines for Fecal Incontinence was published in Japan, followed by the release of this English version. This marks the first major revision in 7 years since the publication of the first edition. The second edition was completed over a span of 3 years, and its overview and key features are summarized below. This guideline begins with a clinical flowchart outlining the general diagnostic and therapeutic approach. A notable update is the inclusion of insertable anal and vaginal continence devices, which are now considered a form of conservative therapy under clinical research frameworks. In Chapter I-B (Epidemiology), the prevalence of anal incontinence was newly reported: among a Japanese population with an average age of 35 years, 15.5% of men and 42.7% of women were affected. In Chapter II (Diagnosis), the utility of a bowel diary for patient assessment is discussed for the first time. The guideline also provides a detailed description of the evaluation method for digital rectal examination. Additionally, a new section was added addressing incontinence-associated dermatitis (IAD), including its risks and methods of assessment. In Chapter III (Diagnostic Testing), the guideline expands upon previously established diagnostic tests by newly including detailed descriptions of ultrasound techniques-specifically, endoanal ultrasound, transperineal ultrasound, and transvaginal ultrasound. Chapter IV (Treatment) outlines conservative treatment strategies, including dietary guidance, bowel habit instruction, and care for fecal incontinence. Pharmacologic therapies are presented with itemized explanations by drug type. Pelvic floor muscle training, biofeedback therapy, and transanal irrigation are classified under "specialized conservative therapies" and discussed in detail. For surgical treatment, a new Clinical Question (CQ) addresses postpartum fecal incontinence. It recommends early referral to a specialized center when a sphincter injury is present to be repaired, whereas observation for one year may be appropriate when no injury is identified. Another new CQ discusses the mode of delivery in subsequent pregnancies following obstetric anal sphincter injuries (OASIS), emphasizing the need to evaluate fecal incontinence severity, anal sphincter function, and its integrity before making clinical decisions. Stoma creation is described in detail as one of the surgical treatment options, including its implications for improved postoperative quality of life. For the first time, regenerative therapy for the anal sphincter is introduced as a novel surgical option, reporting promising long-term outcomes from trials involving the transplantation of autologous cultured myoblasts into the external anal sphincter. Finally, Chapter V addresses special clinical scenarios in detail, including fecal incontinence associated with neurological and spinal disorders, dementia, frailty, and bedridden elderly patients.
The number of patients with inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), continues to increase in many countries and regions. With recent rapid advances in medical therapies targeting intestinal inflammation, the number of patients with long-term disease duration is also increasing. It is well-recognized that longstanding IBD carries an increased risk of developing gastrointestinal (GI) neoplasia, particularly colorectal cancer. However, compared to sporadic GI tumors, IBD-associated GI tumors are relatively rare, and even among specialists in GI diseases, opportunities to encounter such cases remain limited. In light of this situation, the Japanese Society for Cancer of the Colon and Rectum (JSCCR), in collaboration with the Japanese Inflammatory Bowel Disease Research Group (funded by the Japan Sciences Research Grant for Research on Intractable Diseases affiliated with the Ministry of Health, Labour, and Welfare) launched the Guideline Development Committee for IBD-associated Gastrointestinal Tumors in 2021, with the aim of establishing clinical practice guidelines to support the diagnosis and management of these tumors. The committee-comprising experts in gastroenterology, surgery, pathology, guideline development, and literature review-conducted extensive discussions and successfully published the first Japanese edition of the guidelines in July 2024. We believe that the current edition provides the best possible guidance based on presently available knowledge. Furthermore, the guideline development process highlighted several key issues to be addressed in future research and clinical practice. We are pleased to present here the English version of the JSCCR Guidelines 2024 for the Clinical Practice of IBD-associated Intestinal Neoplasia.
Colorectal cancer is the most common malignant disease in Japan. This study aimed to publish data on colorectal cancer cases registered in 2024, focusing on patients who received initial treatment in 2016. Participating facilities of the Japanese Society for Cancer of the Colon and Rectum (JSCCR) registered cases treated in 2016 according to the 8th edition of the Japanese Classification of Colorectal Carcinoma. Data submitted to the National Registration Committee in 2024 were analyzed. A total of 12,825 cases were analyzed. Of these, 1,091 patients underwent endoscopic treatment, 756 underwent additional surgical resection after endoscopic treatment, and 10,806 underwent surgical treatment. Notably, among patients treated endoscopically, the proportion of endoscopic submucosal dissection (ESD) cases increased from 10.1% in 2010 to 25.5% in 2016. This report describes the characteristics, treatment methods, and outcomes of colorectal cancer patients receiving initial treatment in 2016 at JSCCR-affiliated facilities. Notably, the proportion of cases with ESD among all endoscopic procedures increased by more than twofold between 2010 and 2016. These data are expected to be useful for patients to better understand their disease and for healthcare professionals when explaining colorectal cancer and its treatments to patients.
We herein report a rare case of granulocyte colony-stimulating factor (G-CSF)-producing adenosquamous carcinoma of the ascending colon. An 80-year-old man was admitted to our hospital complaining of constipation and hypophagia. His medical history over the past nine years included chronic obstructive pulmonary disease, arteriosclerosis obliterans, and acute limb ischemia. He had no history of inflammatory bowel disease or other gastrointestinal conditions. Colonoscopy and contrast-enhanced computed tomography revealed a tumor in the ascending colon. Biopsies were obtained from five different areas of the lesion, all of which showed histological features consistent with squamous cell carcinoma. Notably, despite the absence of clinical signs of infection, the white blood cell count (WBC) and C-reactive protein (CRP) levels were elevated. Given these findings, a G-CSF-producing tumor was suspected. Subsequent measurement of serum G-CSF levels confirmed this elevation. Based on these findings, we initially suspected G-CSF-producing squamous cell carcinoma of the ascending colon, and proceeded with radical surgical resection. However, the final pathological examination revealed that the tumor contained a minor adenocarcinomatous component (approximately 1%), leading to a definitive diagnosis of adenosquamous carcinoma. We herein review the relevant literature and describe the diagnostic considerations, surgical management, and postoperative course of this rare case.
The number of reports of robotic surgery for colorectal cancer, including reports of simultaneous surgery involving multiple organs, has increased in recent years. We report a case of simultaneous robotic surgery for a giant uterine fibroid and rectal cancer. The patient 45-year-old woman was diagnosed with rectal cancer and a giant uterine fibroid measuring 18 cm in maximum diameter. The uterine fibroid was oriented toward the cervix and was approached from both sides, and the broad ligament of the uterus was cut off using a vessel sealer. The cervix was dissected from the side of the abdominal cavity using monopolar curved scissors. The GelPOINT Access Platform™ was attached to the vagina, and the laparoscopic camera was inserted into the vagina to confirm the resection site. The border between the uterus and rectum was confirmed from both the abdominal cavity and vaginal sides, and simple total hysterectomy was safely performed. The rectum was dissected below the peritoneal reflection. The excised uterine specimen measured 18×13×5 cm long. The patient underwent robotic surgery for a giant uterine fibroid and rectal cancer. It is important to plan and simulate the surgery beforehand as well as select the site for trocar placement.
To retrospectively evaluate the clinical features, perioperative findings, and long-term outcomes of patients who underwent bowel resection for intestinal endometriosis, and to clarify diagnostic and therapeutic challenges with the goal of supporting optimal surgical strategies that minimize recurrence while preserving function. Twenty-one patients who underwent bowel resection for intestinal endometriosis from 2002 to 2022 were evaluated regarding clinicopathological findings and short and long-term outcomes. The median age was 38 years. All patients had gastrointestinal symptoms. Colonoscopy confirmed endometriosis histologically in only 1 patient (7.1%). Lesions were identified in the sigmoid colon to the upper rectum in 17 patients, some of which were accompanied by obliteration of the pouch of Douglas. Low anterior resection was performed in 15 of these patients, and temporary stomas were created in 4 patients. Gynecologic procedures were performed in 9 patients. Histopathology showed invasion into the submucosal and muscular layers. Early complications (Clavien-Dindo ≥2) occurred in 2 patients (anastomotic leak and ileus), while late complications included anastomotic stenosis, bowel stricture, and rectovaginal fistula (1 patient each). Only one recurrence (4.8%) was observed during a median follow-up of 2,088 days. Spontaneous pregnancy was achieved in 2 patients. This study highlights the clinical significance of bowel resection for intestinal endometriosis, suggesting the importance of comprehensive evaluation to improve diagnostic accuracy, the utility of collaboration with gynecology, and the potential for recurrence reduction and functional preservation through appropriate resection margins. These findings may contribute to the development of future treatment strategies for this condition.
This study investigated the incidence of colostomy, aiming to identify its risk factors following chemoradiotherapy (CRT) for squamous cell carcinoma of the anus (SCCA) in a large Asian cohort, and to clarify the prognostic significance of a complete response (CR). While CRT is the standard of care for SCCA, the risk of colostomy remains a major concern due to its potential impact on a patient's quality of life. Prior studies focused mainly on Western populations, and data from Asian cohorts are limited. We conducted a retrospective multicenter study of 246 patients with SCCA who underwent CRT at 47 Japanese Society for Cancer of the Colon and Rectum (JSCCR)-affiliated institutions-the largest Asian cohort analyzed to date. Colostomy incidence, colostomy-free survival (CFS), and associated risk factors were assessed. Consistent with earlier Western reports, the 5-year cumulative colostomy incidence was 20.4% and the CFS rate was 65.9%. Multivariable analysis identified tumor size >50 mm (HR 9.619, P=0.0026) and male sex (HR 5.170, P<0.0001) as independent predictors of colostomy. Failure to achieve CR was strongly associated with higher colostomy risk (HR 3.732, P<0.0001), and local recurrence after CR further increased this risk (HR 16.302, P<0.0001). In this largest Asian cohort to date of patients with SCCA treated with CRT, tumor size, male sex, and abscence of CR emerged as key predictors of colostomy. Early identification of high-risk patients and achieving CR are essential for improving anal preservation and guiding individualized treatment strategies.
Primary colorectal choriocarcinoma is extremely rare with only 35 cases described in the literature during over 40 years. The neoplasm is characterized by biphasic tumor growth composed of adenocarcinomatous and choriocarcinomatous differentiation. Diagnostic elusiveness, aggressive nature and lack of established treatment make the prognosis extremely poor, and most patients die during the first year after diagnosis. We present a 66-year-old man with a primary choriocarcinoma of the transverse colon presenting with peritoneal metastasis and acute colonic obstruction. The patient was treated with systemic three-drug chemotherapy (mFOLFOXIRI: 5-fluorouracil/leucovorin + oxaliplatin + irinotecan) in combination with bevacizumab, a highly active regimen for metastatic colorectal adenocarcinoma. Tumor shrinkage was accompanied by a decrease of mononucleated trophoblast-like carcinoma cells in an endoscopic biopsy during the treatment, and the symptoms of disease were relieved within a quite short period of therapy, though rapid regrowth associated with serum beta human chorionic gonadotropin escalation occurred following discontinuation of therapy. The patient died 8 months after the initial diagnosis. Although our patient survived longer than the median survival period documented in the literature, further cases will need to be examined in the future to establish whether this antitumor treatment is effective to prolong survival.
A 78-year-old woman was diagnosed with lower rectal cancer extending to the dentate line. She underwent preoperative chemoradiotherapy, which resulted in tumor shrinkage and clinical complete response (cCR), leading to the implementation of the "Watch and Wait" strategy. At the 21-month surveillance mark, pruritus and erythematous lesions appeared around her anus, which were histologically diagnosed as secondary Paget disease with invasion based on biopsy specimens. Because the primary lesion maintained cCR, local excision of the skin lesion was performed, and negative resection margins were confirmed by pathological examination. At the 4-year postoperative follow-up, neither local recurrence nor distant metastases were observed. This case suggests that although the primary focus disappeared entirely with the use of chemoradiotherapy, microscopic perianal secondary Paget disease hidden outside the radiation field became apparent during surveillance. As total neoadjuvant therapy (TNT) becomes more widespread, the frequency of cCR is expected to increase. During the "Watch and Wait" period, vigilant observation of the perianal skin as well as the rectal region should be performed.
Colonic self-expandable metallic stents (SEMSs) are widely used for preoperative decompression in obstructive colorectal cancer (CRC) patients undergoing total colonoscopy (TCS). However, the factors influencing the success of TCS and the risk of perforation remain unclear. This study aimed to identify key determinants of successful TCS after SEMS placement. We retrospectively analyzed the clinical data of 48 patients who underwent placement of an 18 mm diameter colorectal SEMS as a bridge to surgery (BTS) at a single center between November 2017 and November 2023. Clinical success was defined as successful TCS regardless of endoscopist or scope change. Patients were divided into successful and unsuccessful TCS groups. The effects of tumor (location, stenosis, depth, and peritoneal dissemination) and procedural variables (timing of TCS, stent size, colonoscope type, and performing endoscopist) were analyzed. The mean patient age was 72 years, and 71% were male. The clinical success rate of TCS was 77% (37/48). Univariate analysis revealed that tumor invasion depth (T4) was significantly associated with TCS failure (odds ratio [OR]: 0.23, P=0.0427). Smaller-diameter colonoscopes were correlated with higher success rates. Synchronous cancers were detected in 10% of the cases. The tumor invasion depth impacts the success of TCS. Smaller-diameter scopes may improve outcomes, particularly with deeper tumor invasion.
Hemorrhoids manifest with a range of symptoms and severities, prompting the development of various conservative, interventional, and surgical treatments. Selecting the most suitable treatment for each case is challenging, especially with the continuous evolution of new methods. This review aims to advance hemorrhoid treatment and research by exploring recent developments over the last five years. Conservative approaches have focused on isolating active ingredients from traditional herbal remedies to create new products and understand their mechanisms. In office-based treatments, advanced devices such as modified rubber band ligation and polymer clips with stronger binding forces have been introduced. Polidocanol in foam form has shown promise in sclerotherapy, while infrared coagulation is being replaced by alternative energy-based methods. Additionally, endoscopic office treatments and embolization of hemorrhoidal vessels via angiography are increasingly used as safer options for patients with high surgical risks or bleeding issues. Stapled hemorrhoidopexy has shifted to partial resection instead of complete circular resection, and hemorrhoidal artery ligation techniques have been reported to be effective when combined with stapled hemorrhoidopexy or excisional hemorrhoidectomy in severe cases. Evidence is growing that hemorrhoidal artery ligation remains effective even without Doppler guidance. With ongoing research into various methods, there is a need for scientific comparison and evaluation of their advantages and disadvantages, standardization of indicators and treatment protocols, and cost-effectiveness considerations. Surgeons should offer well-informed options and explanations to patients, based on a comprehensive understanding of available treatments.
There is no consensus on the significance of peritoneal lavage cytology for the prognosis of patients with colorectal cancer. In this prospective multicenter study, we aimed to determine whether positive peritoneal lavage cytology results predict poor patient outcomes and to clarify if the appropriate timing of cytology is before or after tumor resection. Patients diagnosed with pathological stage II or III colorectal cancer between 2013 and 2017 were enrolled in this study. Peritoneal lavage cytology was performed twice, before and after the tumor resection, and the results were analyzed to determine their effect on prognosis and peritoneal recurrence. We analyzed 1378 patients, and 54 (3.9%) had positive cytology results. Furthermore, 30 patients were positive before tumor resection, 13 after tumor resection, and 11 for both markers. The 5-year relapse-free survival rates (5yRFS) with positive and negative cytology before tumor resection in patients with pStage II were 44.4 and 81.7%, respectively (p=0.0014). The 5-year overall survival rates (5yOS) were 57.1 and 91.6%, respectively (p=0.0046). In Stage III, the 5yRFS and 5yOS between patients with positive and negative cytology did not differ. Patients with positive and negative cytology before tumor resection in pStage II had peritoneal recurrence rates of 11.1 and 1.66%, respectively (p=0.034). These rates were 12.5 and 2.51%, respectively, in patients with pStage III (p=0.011). A positive cytology result before tumor resection is a prognostic factor in Stage II colorectal cancer and is instrumental in predicting peritoneal recurrence in Stages II and III colorectal cancer.
Familial adenomatous polyposis (FAP) is an inherited disorder characterized by multiple colorectal polyposis and is frequently associated with a variety of extracolonic lesions. However, neoplastic lesions of the biliary tract system, excluding those of the ampulla of Vater, are extremely rare in FAP, and the impact of APC alterations on their tumorigenesis remains unclear. We aimed to clarify the relationship between germline variants and somatic variants in the APC gene in biliary tract neoplasms (BTNs) of FAP patients. A total of 115 genetically confirmed FAP cases treated at our department between 1997 and 2024 were investigated regarding development of BTNs. APC gene analysis was performed in the BTNs. Of 115 FAP cases, three developed BTNs. Case 1 was a 69-year-old female who underwent subtotal stomach-preserving pancreaticoduodenectomy for duodenal and middle bile duct carcinoma. Case 2 was a 67-year-old female who underwent pancreaticoduodenectomy for gastric, duodenal, and upper bile duct carcinoma. Case 3 was a 47-year-old male who underwent pancreas-sparing total duodenectomy with cholecystectomy for Spigelman Stage IV duodenal polyposis and gallbladder polyposis. In addition to germline pathogenic variants, somatic pathogenic variants of APC were identified in all the BTNs. These findings suggest that the APC two-hit theory may underlie the tumorigenesis of these rare BTNs, consistent with the pathogenic process observed in colonic and other extracolonic lesions in patients with FAP.
Solitary fibrous tumors (SFTs) are rare spindle cell neoplasms of mesenchymal origin, most commonly originating from the pleura. The discovery of the NAB2-STAT6 gene fusion has enabled more accurate diagnosis, particularly in extrapleural locations. We report a rare case of a 50-year-old woman presenting with localized abdominal pain, who showed a 46-mm heterogeneous mass in the left abdomen on contrast-enhanced CT; laparoscopic exploration identified a pedunculated tumor arising from the jejunal mesentery, located 50 cm distal to the ligament of Treitz. Segmental resection of 15 cm of the jejunum with the associated mesentery was performed. The tumor measured 55 × 45 × 30 mm and was confined to the mesentery, with no invasion of the bowel wall. Histopathological examination revealed proliferation of spindle cells within a collagenous stroma, and immunohistochemistry confirmed strong nuclear STAT6 and cytoplasmic CD34 positivity, while c-Kit, DOG1, Desmin, and S-100 were negative, establishing the diagnosis of SFT. The patient's abdominal pain resolved completely following resection. This case highlights the diagnostic challenges of mesenteric SFTs and underscores the importance of complete surgical resection with intact borders and immunohistochemical analysis in securing an accurate diagnosis and favorable outcome.
Preoperative chemotherapy increases resectability in patients with resectable colorectal liver metastasis who undergo curative hepatectomy; however, there is no consensus regarding patient selection. The aim of this study was to identify high-risk patients with synchronous colorectal liver metastasis and compare the outcomes of preoperative chemotherapy with those of upfront surgery. This multi-institutional, retrospective study enrolled patients who underwent their first liver resection for synchronous colorectal liver metastasis from January 2010 to July 2019. We retrospectively studied the clinicopathological features and prognoses of synchronous colorectal liver metastasis subjected to curative liver resection. Surgical outcomes were compared between the preoperative chemotherapy and upfront surgery groups. We analyzed 215 patients categorized into the preoperative chemotherapy (n=111) and upfront surgery (n=104) groups. The distribution of primary colorectal cancer locations significantly differed, and the preoperative chemotherapy group had more and larger tumors than did the upfront surgery group. There were no significant between-group differences in recurrence-free survival and overall survival. Primary lymph node metastasis ≥N2, tumor burden score >5, positive carbohydrate antigen 19-9 on treatment, and the Kirsten rat sarcoma viral oncogene homolog mutation were independent risk factors for recurrence-free survival. The recurrence-free survival rate was significantly higher in the preoperative chemotheapy group than in the upfront surgery group for patients with ≥2 risk factors. Our study suggests new criteria for identifying high-risk patients with synchronous colorectal liver metastasis and shows that preoperative chemotherapy may be an effective option for high-risk patients with ≥2 risk factors.
This study aimed to evaluate short-term outcomes of sacral neuromodulation (SNM) for fecal incontinence (FI) in a Japanese clinical setting, and to assess the predictive value of response during the test stimulation phase. We retrospectively evaluated patients with FI who underwent SNM between 2014 and 2024. Patients proceeded to permanent implantation following a 2-week test stimulation. Primary outcomes included changes in weekly FI episodes, Cleveland Clinic Florida Fecal Incontinence Score (CCFIS), Fecal Incontinence Severity Index (FISI), and Japanese Fecal Incontinence Quality of Life Scale (JFIQL). Anorectal manometry data were also assessed. A receiver operating characteristic (ROC) curve was constructed to investigate the predictive utility of test-phase response. Of 34 patients, 32 (94.1%) proceeded to implantation. Two subsequently required explantation, and 30 completed the 12-month follow-up. At 12 months, median weekly FI episodes decreased from 7.5 to 3.0, CCFIS from 15.0 to 9.0, and FISI from 36.5 to 22.5; JFIQL improved from 2.02 to 2.53 (all p < 0.05). A ≥50% reduction in FI episodes was achieved in 20 of 30 patients (66.7%). Maximum squeezing pressure significantly increased from 90.0 to 107.0 mmHg (p = 0.013), while maximum resting pressure did not change significantly. ROC analysis yielded an area under the curve (AUC) of 0.663, identifying a 36.4% reduction in FI episodes during the test phase. SNM demonstrated favorable short-term outcomes in Japanese patients with FI, including improved continence, quality of life, and anal sphincter function. Early partial response during the test phase may serve as a useful predictor of sustained benefit.
Postoperative clinical recurrence is common in patients with Crohn's disease (CD) despite intestinal resection. Although histopathological findings at resection margins suggestively influence recurrence, their prognostic value remains unclear. This study evaluated the pathological features of the intestinal resection margins in CD and assess their utility in predicting postoperative clinical recurrence. This retrospective, single-centre cohort study included 224 patients with CD who underwent intestinal resection without visible residual disease at the Tokyo Yamate Medical Center between January 2019 and December 2021. The patients were followed up until July 2024. The histological features at the resection margins, including plexitis, positive margins, granulomas, and lymphoid follicles, were graded using standardised systems. Associations between these histopathological findings, preoperative clinical characteristics, and clinical recurrence were analysed using univariate and multivariate methods; survival analyses used the Kaplan-Meier method and Cox proportional hazards models. Severe plexitis at the proximal margin was found in 60.3% of cases and was not associated with preoperative clinical factors or distance from macroscopic lesions. Cox regression identified severe plexitis (hazard ratio [HR]: 1.64, 95% confidence interval [CI]: 1.11-2.44, p=0.013) and lack of prophylactic treatment (HR: 1.64, 95% CI: 1.14-2.35, p=0.007) as independent predictors of clinical recurrence. A stepwise relationship was observed between plexitis severity and recurrence risk. Severe plexitis at the proximal margin is an independent histopathological predictor of CD postoperative clinical recurrence and is unaffected by preoperative factors or resection length, serving as an objective and valuable marker for postoperative risk stratification.
The albumin-bilirubin (ALBI) score and colon inflammatory index (CII) are new sensitive scoring systems for several cancers. However, their clinical significance in colorectal cancer remains unclear. This study investigated the significance of ALBI score and CII for prognosis after colorectal cancer surgery. The present study analyzed data from patients who underwent curative resection for colorectal cancer. We investigated the association between preoperative ALBI score, CII, and disease-free and overall survival following surgery. Univariate and multivariate analyses were conducted to identify independent risk factors for poor prognosis in patients with colorectal cancer. A total of 234 patients were included in the present study. Kaplan-Meier analysis demonstrated that patients with higher ALBI scores and poor CII had significantly worse disease-free and overall survival. In multivariate analysis, ALBI score ≥ -2.45 (P = 0.002), CII poor (P < 0.001), and pathological N1-3 stage (P = 0.017) were independent predictors of disease-free survival. Similarly, ALBI score ≥ -2.45 (P < 0.001 ), CII poor (P = 0.003), and pathological N1-3 stage (P = 0.015) were independent predictors of overall survival. ALBI score and CII were strong predictors of poor prognosis in patients who underwent curative resection for colorectal cancer, emphasizing their potential utility in clinical practice. Incorporating these markers into routine clinical practice may enhance individualized treatment strategies and postoperative surveillance.
Sarcopenia is generally defined based on the age-related muscle mass and weakness. However, it has been reported that patients with Crohn's disease, who develop severe inflammation of the gastrointestinal tract, are more likely to develop sarcopenia. We retrospectively investigated the effect of the iliopsoas muscle area, which is an indicator of sarcopenia, on postoperative complications in patients with Crohn's disease. We included 98 patients with Crohn's disease who underwent surgery in our department between January 2016 and December 2021, and performed retrospectively analyzed. The psoas muscle index (PMI) was calculated as the average of the left and right iliopsoas muscles (L3, cm2) / height2. We divided patients into the low PMI (men <2.33 cm2/m2, women <1.85 cm2/m2) and normal PMI groups and compared their preoperative and intraoperative factors and postoperative outcomes. The median age of the 98 patients was 37.0 (17-77) years. Complications were noted in 40 patients (40.8%), including 10 (10.2%) with anastomotic leakage. There were 26 (26.5%) patients with a low PMI. The incidence of all postoperative complications, grade ≥2 complications, anastomotic leakage and surgical site infection (SSI) were significantly higher in the low-PMI group than in the normal-PMI group. According to a multivariate analysis, low PMI (p=0.04) was only independent predictor for grade 2 or above postoperative complications. A low PMI is associated with postoperative complications, especially anastomotic leakage, in patients with Crohn's disease.
Robot-assisted surgery has rapidly expanded worldwide. The hinotori™ Surgical System (hinotori), the first domestically developed robotic platform in Japan, has recently been introduced in colorectal surgery. This study aimed to evaluate the clinical outcomes of colorectal procedures performed using the hinotori. A single-center retrospective observational study was conducted on consecutive patients who underwent robot-assisted colorectal surgery with the hinotori at Kyoto University Hospital between August 2023 and November 2025. Patient demographics, operative details, and short-term outcomes were analyzed separately for colon and rectal cancer. A total of 94 patients were included: 53 with colon cancer and 41 with rectal cancer. In the colon cancer group, the median operative time was 255 minutes, and one patient (1.9%) developed a Clavien-Dindo grade II complication; no grade ≥III events occurred. In the rectal cancer group, the median operative time was 327 minutes, and one patient (2.4%) experienced a grade II complication; no grade ≥III complications occurred. No conversions to open surgery and no reoperations within 30 days were observed. The median postoperative hospital stay was 10 days for colon cancer and 12 days for rectal cancer. Robot-assisted colorectal surgery using the hinotori was safe and feasible. This largest case series to date provides data supporting its feasibility and safety.