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Abstract We developed a novel clamping device for laparoscopic surgery, free from conventional pinch structure, capable of uniformly occluding any ductal organ. This study aimed to evaluate performance of the new clamper compared to the pinch-type clamper. The new clamper consists of two metal bars with ties at each end, which enables parallel clamping. A resected porcine stomach was used, with an infusion tube at the anal end to increase intra-luminal pressure. The oral side of the stomach was clamped with either the new clamper or the pinch-type clamper, and their performances were evaluated in qualitative and semi-quantitative manner. Qualitative evaluation involved imaging the clamping site at intra-gastric pressures from 0 to 15 mmHg using microfocus computed tomography. The new clamper showed no gap even under increased intra-luminal pressure, while the pinch-type clamper showed a gap on the distal side. Quantitative evaluation measured bursting pressure under continuous air insufflation. Air leakages were observed in the new clamper at higher intra-luminal pressures than in the pinch-type clamper (46.1 mmHg vs. 13.6 mmHg, P

Abstract Background Local recurrence is common after curative resections of rectal cancer. Surgical resection is considered a primary curative treatment option for patients with locally recurrent rectal cancer (LRRC). LRRC often requires a combined resection of other organs, especially in the case of posterior recurrence, which requires a combined resection of the sacrum, making the surgery highly invasive. Venous thromboembolism (VTE) is one of the lethal complications in the postoperative period, particularly in the field of pelvic surgery. We found no reports regarding the risks of postoperative VTE in surgery for LRRC, a typical highly invasive procedure in the field of colorectal surgery. This study aims to evaluate the risk of postoperative VTE in surgery for LRRC patients. Methods From April 2010 to March 2022, a total of 166 patients underwent surgery for LRRC in the pelvic region at our institutions. Clinicopathological background and VTE incidence were compared retrospectively. Results Among the 166 patients included in the study, 55 patients (33.1%) needed sacral resection. Pharmacological prophylaxis for prevention of VTE was performed in 121 patients (73.3%), and the incidence of VTE was 9.09% (5/55 patients) among those who underwent surgery for LRRC with sacral resection, while it was 1.8% (2/111 patients) in those without sacral resection. In univariate analysis, the combination with sacral resection was identified as a risk factor for VTE in surgery for LRRC (p = 0.047). Conclusions This study demonstrates that surgery for LRRC combined with sacral resection could be a significant risk factor for VTE.

Abstract Background Anorectal fistula cancer is often diagnosed in an advanced state, and radical resection is difficult when invasion of the pelvic wall is observed. In addition, there is currently no clear evidence for perioperative treatment of locally advanced cases. We report a case of anorectal fistula cancer with widespread infiltration diagnosed during the course of Crohn’s disease, which was curatively resected after preoperative chemoradiotherapy. Case presentation A 49-year-old man who had been diagnosed with Crohn’s disease (ileocolonic type) at the age of 25 and was found to have an anorectal fistula and perianal abscess at the age of 44 was referred to our department with complaints of abdominal pain and diarrhea. Computed tomography (CT) showed anal stenosis due to a pelvic mass. Pathological analysis of a biopsy taken under general anesthesia indicated mucinous carcinoma. Magnetic resonance imaging (MRI) revealed infiltration into the prostate, seminal vesicles, levator ani muscle, and left internal obturator muscle, and the patient was diagnosed with cT4N0M0 cStage IIIB anorectal fistula cancer (UICC TNM classification 8th edition). After performing a laparoscopic sigmoid colostomy, chemoradiation therapy (capecitabine + oxaliplatin, 50.4 Gy/28fr) was initiated. The patient then underwent laparoscopic total pelvic exenteration, colonic conduit diversion, extensive perineal resection, and reconstruction using bilateral gluteus maximus flaps and a right rectus abdominis musculocutaneous flap. The pathological diagnosis was mucinous adenocarcinoma, pT4, and all margins were negative. No recurrence was evident 6 months after the operation without adjuvant chemotherapy. Conclusion We described a case of curative resection after preoperative chemoradiotherapy for anorectal fistula cancer with extensive invasion that was diagnosed during the course of Crohn’s disease.An accumulation of cases is needed to determine the usefulness of preoperative chemoradiation therapy for local control of anorectal fistula cancer associated with Crohn’s disease.

Here we report a case of locally advanced rectal cancer with vaginal invasion, which was successfully resected via laparoscopic surgery using intraoperative indocyanine green (ICG) navigation to determine the vaginal cut line. Based on preoperative examinations, an 81-year-old female was diagnosed with locally advanced rectal cancer with vaginal invasion. After preoperative chemoradiotherapy, the lesion was judged to be resectable. During surgery, the gynecologist transvaginally injected ICG into the vaginal submucosa to determine the caudal margin of the vaginal invasion, and laparoscopically dissected under the near-infrared image of the stained area. Pathological analysis of the resection specimen revealed negative resection margins. One year after surgery, there has been no recurrence.

Abstract Background Metastatic testicular cancer is rare. In particular, primary colorectal cancer rarely metastasizes to the testes. This study reports a case of testicular metastasis recurrence 9 years after the resection of a primary colorectal cancer and a simultaneous metastatic lung tumour. Case presentation A 69-year-old man underwent a laparoscopic left hemicolectomy for descending colon cancer. Preoperative computed tomography revealed a solitary left lung mass. Postoperative chemotherapy reduced the size of the lung mass, and 6 months after the primary resection, the patient underwent a left upper segmentectomy. Based on the pathological examination, he was diagnosed with pulmonary metastasis from colorectal cancer. After four courses of adjuvant chemotherapy, the patient was recurrence-free. However, 9 years and 6 months after the primary resection, he complained of discomfort in his left testicle. Physical examination revealed a left testicular mass. Since a malignancy was not excluded via imaging, left testicular resection was performed to confirm the diagnosis. The pathological diagnosis was testicular metastasis from colorectal cancer. The patient was followed up without medication, and remained healthy, without recurrence, 11 months postoperatively. Conclusions It is important to follow up with testicular metastasis in mind, although it is rare.

Abstract Approximately 10% of patients with colorectal cancer with submucosal invasion have lymph node metastasis. Pathological risk factors for lymph node metastasis have varying sensitivities and specificities. To predict the risk of lymph node metastasis, the identification of new risk factors is vital. Tumor-infiltrating T cells have been reported to improve the prognosis of many solid tumors. Therefore, the purpose of this study was to examine the relationship between lymph node metastasis and tumor-infiltrating T cells in patients with colorectal cancer with submucosal invasion. We examined CD8+ tumor-infiltrating T cells level as a risk factor for lymph node metastasis in patients with colorectal cancer with submucosal invasion. Using immunohistochemical staining, we identified CD8 + T cells in surgically resected specimens from 98 patients with SM-CRC. We showed that low CD8+ tumor-infiltrating T cells levels are positively correlated with lymph node metastasis. Furthermore, by combining the number of CD8+ tumor-infiltrating T cell and the number of CD103+ tumor-infiltrating T cells, the results showed a high positive predictive value for lymph node metastasis in cases with low numbers of both types of tumor-infiltrating T cells and a high negative predictive value in cases with high numbers of both types of tumor-infiltrating T cells.

Abstract Background The standard treatment for locally advanced rectal cancer (LARC) is preoperative chemoradiotherapy (CRT) followed by surgery and adjuvant chemotherapy. However, it has been suggested that intensification of neoadjuvant treatment with polychemotherapy in addition to CRT instead of as an adjuvant chemotherapy is better tolerated and associated with a higher pathological complete response (pCR) rate. This concept is known as total neoadjuvant therapy (TNT). Recently, the addition of immunotherapy to preoperative CRT has been reported to be useful in LARC patients with mismatch-repair-deficiency and high levels of microsatellite instability (MSI-H), but there are no reports showing the therapeutic effect of nivolumab in combination with TNT. Case presentation A 23-year-old man had frequent diarrhea. Preoperative examination revealed two adenocarcinomas in the rectum. His maternal grandmother had a rectal cancer patient who developed the disease at age 70s. The larger tumor was located at the peritoneal reflection, and its anterior border close to the prostate (

Abstract Background Despite advances in medical treatments, most patients with Crohn's disease (CD) will still require surgery, with 20%‐50% needing redo surgery within 10 years after the primary procedure. There is no consensus on the application of laparoscopic redo surgery for recurrent CD. Methods This study included 107 patients with CD who underwent surgery from 2012 to 2020 at Osaka University Hospital. All procedures were laparoscopic. Patients were grouped based on whether the surgery was redo or primary for evaluation of the safety and feasibility of laparoscopic redo surgery. Results The study included 40 patients undergoing redo surgery and 67 having primary surgery. The median age at the time of the procedure was higher for those undergoing redo surgery (43 years vs 34 years, P

Abstract Background Stoma outlet obstruction (SOO) is much more common after total proctocolectomy (TPC) and ileal‐pouch anal anastomosis (IPAA) for ulcerative colitis (UC) compared to after rectal surgery for cancer. Few prior reports have evaluated anatomical risk factors for SOO. In this study we aimed to clarify the risk factors for SOO after IPAA, focusing on the anatomical perspective. Methods This study included 68 UC patients who underwent IPAA with diverting ileostomy. These cases were analyzed based on clinicopathological factors and computed tomography (CT)‐based anatomical factors. Results SOO was identified in 18 patients (26.5%). We compared this SOO group with the non‐SOO group. The two groups significantly differed in sex distribution, and patients in the SOO group tended to have a longer postoperative hospital stay. Regarding surgery‐related factors, patients who underwent two‐stage surgery and experienced high‐output syndrome tended to develop SOO. Analysis of anatomical risk factors revealed that SOO was more common in patients with a longer distance between the root of their superior mesenteric artery and the bottom of the external anal sphincter (rSMA‐bEAS). This tendency remained significant even with adjustment for patient height. In multivariate analyses, adjusted rSMA‐bEAS (>191.0 mm/m) and male sex were independent risk factors associated with SOO. Conclusion A long rSMA‐bEAS distance suggests that the mesentery is likely to be under tension. In such cases, surgeons should endeavor to avoid tension in the mesentery as much as possible.

The novel coronavirus disease 2019 (COVID-19) caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread at a very fast rate, overwhelming and disrupting healthcare systems around the world since its outbreak in December 2019 in China. As of October 2021, the total number of COVID-19 cases exceeds 240,000,000, and the total number of deaths is close to 5,000,000. In the situation of widespread SARS-CoV-2 infection, restrictions on the medical system due to shifts in medical care to accommodate the pandemic will occur, and its impact on surgical and endoscopic treatment for colorectal cancer is inevitable. Therefore, it is necessary to satisfy all of the following requirements: patient safety, prevention of exposure of healthcare workers including surgeons, prevention of nosocomial infection, and a decision on how to treat the primary disease. Surgical triage is also required, based on comprehensive consideration of the patient's condition, the severity of the disease, the SARS-CoV-2 infection situation in the region, and the medical supply system at each facility, including medical resources, human resources, and the availability of medical equipment. Understanding the diagnostic and treatment environment that the COVID-19 pandemic has dramatically changed is important in providing appropriate surgical care to patients who require surgery while taking utmost care to prevent the spread of COVID-19.

The incidence of inflammatory bowel disease (IBD) is increasing worldwide. It is reported that TGF-β/Smad signal pathway is inactivated in patients with Crohn’s disease by overexpression of Smad 7. With expectation of multiple molecular targeting by microRNAs (miRNAs), we currently attempted to identify certain miRNAs that activate TGF-β/Smad signal pathway and aimed to prove in vivo therapeutic efficacy in mouse model. Through Smad binding element (SBE) reporter assays, we focused on miR-497a-5p. This miRNA is common between mouse and human species and enhanced the activity of TGF-β/Smad signal pathway, decreased Smad 7 and/or increased phosphorylated Smad 3 expression in non-tumor cell line HEK293, colorectal cancer cell line HCT116 and mouse macrophage J774a.1 cells. MiR-497a-5p also suppressed the production of inflammatory cytokines TNF-α, IL-12p40, a subunit of IL-23, and IL-6 when J774a.1 cells were stimulated by lipopolysaccharides (LPS). In a long-term therapeutic model for mouse dextran sodium sulfate (DSS)-induced colitis, systemic delivery of miR-497a-5p load on super carbonate apatite (sCA) nanoparticle as a vehicle restored epithelial structure of the colonic mucosa and suppressed bowel inflammation compared with negative control miRNA treatment. Our data suggest that sCA-miR-497a-5p may potentially have a therapeutic ability against IBD although further investigation is essential.

Postoperative complications related to anastomosis, including postoperative anastomotic bleeding and anastomotic leakage, remain a serious issue. The effect of anastomotic devices on suture complications during intestinal anastomosis remains unclear. The present study examined the utility of automated anastomotic devices for reducing anastomotic complication risks. A retrospective cohort study of colorectal cancer surgeries in which an anastomosis device was used at Osaka University Hospital (Suita, Japan) between January 2018 and December 2022 was conducted. Cases of emergency surgery, inflammatory bowel disease and simultaneous surgery for other cancers were excluded. Experienced gastrointestinal surgeons performed manual anastomosis using the ETHICON Circular Stapler CDH or EEA Circular Stapler, and automatic anastomosis using the ECHELON CIRCULAR Powered Stapler, with no observed operator bias. Additionally, a meta-analysis that included other study results was performed. The outcomes included postoperative complications, mainly anastomotic leakage. The study included 414 patients: 231 in the manual circular stapler group and 183 in the powered circular stapler (PCS) group. Although this retrospective study found no statistically significant association between the anastomotic device used and anastomotic complications, an increased risk ratio was observed in the manual group compared with the automatic group when restricted to elderly patients. Similarly, a meta-analysis found a significantly higher anastomotic complication risk in the manual group compared with the automatic group (random-effects model; odds ratio, 0.376; 95% confidence interval, 0.232-0.610; P<0.0001). The findings of the present study suggested that a PCS is useful for reducing the anastomotic complication risk in patients undergoing colorectal cancer surgery. [ABSTRACT FROM AUTHOR]

Background/Aim: Transanal endoscopic local excision requires fine operation in a very narrow space in the rectum. We report a case in which the use of surgical instruments with a multi-jointed structure allowed safe resection of a lesion with a stable field of view, resulting in preservation of postoperative function. Case Report: The patient was a 49-year-old man who had a rectal neuroendocrine tumor (NET) (G1) with erosive changes in the lower rectum. Preoperative imaging showed no evidence of surrounding lymph node or distant metastasis; thus, we performed a transanal endoscopic local excision of the tumor. After positioning the patient under general anesthesia and securing the field of view in the intra-rectal cavity, the flexion of the surgical instruments with a multi-jointed structure was used to secure the operating space to not interfere with the camera and the surgeon’s right hand. The operating field was developed, and the tumor was incised by stable traction. After the excision, the needle was advanced in the direction of the intestinal axis using the multi-jointed holder, and continuous suturing was performed. The patient has no recurrence without any defecation disorder. Conclusion: The use of multijointed surgical instruments in transanal endoscopic excision of rectal tumors can provide a stable operative field and preserve postoperative function. The advanced flexibility of these instruments allows precise manipulation in the narrow rectal space, resulting in successful tumor resection with minimal invasiveness and no postoperative complications. These findings suggest that multi-jointed instruments are valuable for enhancing the safety and efficacy of minimally invasive rectal surgery. [ABSTRACT FROM AUTHOR]

Background Pouch-related complications (PRCs), such as pelvic abscesses and perianal complex fistulas, can occur after ileal pouch–anal anastomosis (IPAA) in ulcerative colitis (UC). They are often difficult to treat and require salvage surgery. We report two cases of PRC associated with fistulas. Case presentation First case: A 38-year-old man was diagnosed with UC at age 26 years. Four months after the diagnosis of UC, the patient underwent hand-assisted laparoscopic restorative proctocolectomy, IPAA, and ileostomy for acute fulminant UC. Two years after the closure of the ileostomy, the patient developed a perianal abscess and underwent ileostomy reconstruction. He was referred to our department at 35 years of age, because his symptoms did not improve despite repeated seton drainage of a complicated perineal fistula. We diagnosed PRC with a pelvic abscess and complicated pouch fistula and performed salvage surgery. This diagnosis was revised to Crohn’s disease. Second case: A 50-year-old man was diagnosed with UC at age 18 years and was administered high doses of steroids; however, his symptoms did not improve. He underwent restorative proctocolectomy, IPAA, and ileostomy at another hospital. The ileostomy was closed, and his condition stabilized thereafter. At 35 years of age, perianal pain developed, and he was diagnosed with a complicated pouch–perineal fistula. A fistula was observed near the staple line of the ileal end closure on the head side of the pouch. Reconstruction of the ileostomy and seton drainage were performed; however, his symptoms did not improve, and he was referred to our hospital. We diagnosed PRC with a pelvic abscess and a complicated pouch fistula and performed salvage surgery. The resected specimen showed strictures in two locations: at the oral site of the afferent limb (at the pouch) and at the IPAA. Both patients returned to society and are currently outpatients. Conclusions We encountered two cases of PRC after IPAA that did not improve with seton drainage or ileostomy. Pouch resection was performed after considering the patient’s quality of life and reintegration into society. [ABSTRACT FROM AUTHOR]

Background/Aim: Intestinal malrotation (IM) often remains undetected until adulthood, being discovered during testing or surgery for other comorbidities. Preoperative understanding of this anatomical abnormality is crucial. Case Report: An 80-year-old woman presented with cecal cancer. Three-dimensional computed tomography (CT) revealed that the cecum was located at the midline of the abdominal cavity, the duodenum did not cross the midline, and the ileocolic vein ran to the left. Clinically diagnosed with stage IVc cecal cancer complicated by IM, the patient underwent laparoscopic surgery. The ascending colon and cecum were not fixed to the retroperitoneum. The duodenum lacked the second, third, and fourth portions and the small bowel was distributed on the left and right sides of the abdominal cavity. Adhesions had shortened the mesentery, which were released close to their normal positions. Conclusion: Although laparoscopic surgery is superior to open surgery in terms of securing the field of view in a narrow space, providing a magnifying effect, and minimal invasiveness, it has a limited field of view and is inferior in terms of grasping the overall anatomy, which may be disadvantageous in cases of anatomical abnormalities. Colorectal cancer with IM is rare; however, the rate of preoperative diagnosis seems to be increasing thanks to improvements in diagnostic imaging, such as three-dimensional CT scans. In this study, we also reviewed 49 cases of colorectal cancer associated with IM. [ABSTRACT FROM AUTHOR]

In current clinical practice, several treatment methods, including neoadjuvant therapy, are being developed to improve overall survival or local recurrence rates for locally advanced rectal cancer. The response to neoadjuvant therapy is usually evaluated using imaging data collected before and after preoperative treatment or postsurgical pathological diagnosis. However, there is a need to accurately predict the response to preoperative treatment before treatment is administered. The present study used a deep learning network to examine colonoscopy images and construct a model to predict the response of rectal cancer to neoadjuvant chemotherapy. A total of 53 patients who underwent preoperative chemotherapy followed by radical resection for advanced rectal cancer at the Osaka University Hospital between January 2011 and August 2019 were retrospectively analyzed. A convolutional neural network model was constructed using 403 images from 43 patients as the learning set. The diagnostic accuracy of the deep learning model was evaluated using 84 images from 10 patients as the validation set. The model demonstrated a sensitivity, specificity, accuracy, positive predictive value and area under the curve of 77.6% (38/49), 62.9% (22/33), 71.4% (60/84), 74.5% (38/51) and 0.713, respectively, in predicting a poor response to neoadjuvant therapy. Overall, deep learning of colonoscopy images may contribute to an accurate prediction of the response of rectal cancer to neoadjuvant chemotherapy. [ABSTRACT FROM AUTHOR]

Background/Aim: Recently, robotic surgery for rectal cancer has become a common minimally invasive surgery. In addition, the technology of augmented and mixed reality is applied in various living environments, including medicine. We successfully performed robotic surgery for rectal cancer with three-dimensional (3D) images as mixed reality (MR) using HoloLens2. Case Report: The patient was diagnosed with rectal cancer by colonoscopy and a positron-emission computedtomography scan, and we performed robot-assisted anterior resection. The operator used HoloLens2 and performed the surgery while visualizing 3D images of pelvic anatomy with the location of the rectal cancer as hologram. The operation was performed completely and safely, and she was discharged 11 days after surgery with no postoperative complications. Conclusion: This case presents the usefulness of a MR system offering organ visualization as hologram during surgery. [ABSTRACT FROM AUTHOR]

T cells differentiate into highly diverse subsets and display plasticity depending on the environment. Although lymphocytes are key mediators of inflammation, functional specialization of T cells in inflammatory bowel disease (IBD) has not been effectively described. Here, we performed deep profiling of T cells in the intestinal mucosa of IBD and identified a CD4+ tissue-resident memory T cell (Trm) subset that is increased in Crohn's disease (CD) showing unique inflammatory properties. Functionally and transcriptionally distinct CD4+ Trm subsets are observed in the inflamed gut mucosa, among which a CD-specific CD4+ Trm subset, expressing CD161 and CCR5 along with CD103, displays previously unrecognized pleiotropic signatures of innate and effector activities. These inflammatory features are further enhanced by their spatial proximity to gut epithelial cells. Furthermore, the CD-specific CD4+ Trm subset is the most predominant producer of type 1 inflammatory cytokines upon various stimulations among all CD4+ T cells, suggesting that the accumulation of this T cell subset is a pathological hallmark of CD. Our results provide comprehensive insights into the pathogenesis of IBD, paving the way for decoding of the molecular mechanisms underlying this disease. [ABSTRACT FROM AUTHOR]

Postoperative carcinoembryonic antigen (post-CEA) has recently been reported to be a reliable prognostic factor for colon cancer. However, most clinicians decide whether or not to conduct adjuvant chemotherapy (AC) for stage II colon cancer according to major guidelines, which do not include post-CEA in their high-risk criteria. The present study aimed to assess post-CEA in stage II colon cancer for which the significance of AC is unknown. The present study analyzed 199 consecutive patients with stage II colon cancer who underwent curative surgery between January 2007 and December 2016. The CEA value was considered high when it was =5.0 ng/ml. The prognostic value of high post-CEA values was assessed. Overall, 19 patients exhibited high post-CEA levels. Kaplan-Meier survival curve analysis demonstrated that patients with high post-CEA levels had significantly worse relapse-free survival (RFS) and overall survival (OS) than those with normal post-CEA [RFS, 63.5 (high post-CEA) vs. 88.0% (normal post-CEA), P=0.003; OS, 76.5 (high post-CEA) vs. 96.8% (normal post-CEA), P<0.001]. Multivariate analysis demonstrated that high post-CEA remained a significant independent risk factor for worse RFS [hazard ratio (HR), 3.98; P=0.006]. The same was also demonstrated for patients without AC (HR, 5.43; P=0.008). To the best of our knowledge, the present study was the first to demonstrate that high post-CEA levels may be an indicator of high-risk stage II colon cancer, even for patients without AC. These results highlight the need for a multicenter prospective study. [ABSTRACT FROM AUTHOR]