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Introduction Pelvic arteriovenous malformation is often a source of intraoperative bleeding. Here, we report our experience with a case of ureteral cancer with pelvic arteriovenous malformation treated using laparoscopic nephroureterectomy with temporary intraoperative occlusion of the internal iliac artery. Case presentation A 75‐year‐old man presented to our hospital with asymptomatic macro‐hematuria. Contrast‐enhanced computed tomography revealed right ureteral tumor with no apparent metastases, and right pelvic arteriovenous malformation. Three months later, multiple bladder cancers were identified and the patient underwent trans‐urethral resection of bladder tumor. The pathological diagnosis was urothelial carcinoma, pTa. We performed right laparoscopic nephroureterectomy with temporary intraoperative occlusion of the internal iliac artery. There was little intraoperative bleeding, and the surgery was safely completed. The pathological diagnosis was urothelial carcinoma, pT2 + Tis. Conclusion A patient showing ureteral cancer with pelvic arteriovenous malformation was safely treated using laparoscopic nephroureterectomy with temporary occlusion of the internal iliac artery.

Purpose A consensus has been reached regarding diverting stoma (DS) construction in rectal cancer surgery to avoid reoperation related to anastomotic leakage. However, the incidence of stoma-related complications (SRCs) remains high. In this study, we examined the perioperative outcomes of DS construction in patients who underwent sphincter-preserving surgery for rectal cancer. Methods We included 400 participants who underwent radical sphincter-preserving surgery for rectal cancer between 2005 and 2017. These participants were divided into the DS (+) and DS (–) groups, and the outcomes, including postoperative complications, were compared. Results The incidence of ileus was higher in the DS (+) group than in the DS (–) group (P

Abstract Background Intensive localized therapy is promising for the treatment of rectal cancer. In Japan, chemoradiotherapy (CRT) and neoadjuvant chemotherapy (NAC) are used as preoperative treatments for this disease. Magnetic resonance imaging (MRI) is used to diagnose lateral pelvic node (LPN) metastases, but the changes in LPN findings on MRI following preoperative treatment are unclear. Furthermore, there may be patients in whom LPN dissection can be omitted after CRT/NAC. Methods Patients who underwent total mesorectal excision with LPN dissection after CRT/NAC at 13 Japanese Society for Cancer of the Colon and Rectum member institutions between 2017 and 2019 were included. Changes in the short diameter of the LPNs after CRT/NAC and the reduction rate were examined. Results A total of 101 LPNs were examined in 28 patients who received CRT and 228 in 47 patients who received NAC. Comparison of LPNs before and after CRT/NAC showed that most LPNs shrank after CRT but that the size reduction was variable after NAC. Although some LPNs with a short diameter of

Abstract Background Sarcopenia is characterized by reduced skeletal muscle volume and is a condition that is prevalent among elderly patients and associated with poor prognosis as a comorbidity in malignancies. Given the aging population over 80 years old in Japan, an understanding of malignancies, including colorectal cancer (CRC), complicated by sarcopenia is increasingly important. Therefore, the focus of this study is on a novel and practical diagnostic approach of assessment of psoas major muscle volume (PV) using 3-dimensional computed tomography (3D-CT) in diagnosis of sarcopenia in patients with CRC. Methods The subjects were 150 patients aged ≥ 80 years with CRC who underwent primary tumor resection at Juntendo University Hospital between 2004 and 2017. 3D-CT measurement of PV and conventional CT measurement of the psoas major muscle cross-sectional area (PA) were used to identify sarcopenia (group S) and non-sarcopenia (group nS) cases. Clinicopathological characteristics, operative results, postoperative complications, and prognosis were compared between these groups. Results The S:nS ratios were 15:135 for the PV method and 52:98 for the PA method. There was a strong positive correlation (r = 0.66, p

Abstract Aim The aim of this study was to clarify the significance of resection of ovarian metastases from colorectal cancer and to identify the clinicopathologic characteristics. Methods In this multicenter retrospective study, we evaluated data on ovarian metastases from colorectal cancer obtained from patients at 20 centers in Japan between 2000 and 2014. We examined the impact of resection on the prognosis of patients with ovarian metastases and examined prognostic factors. Results The study included 296 patients with ovarian metastasis. The 3‐y overall survival rate was 68.6% for solitary ovarian metastases. In all cases of this cohort, the 3‐y overall survival rates after curative resection, noncurative resection, and nonresection were 65.9%, 31.8%, and 6.1%, respectively (curative resection vs noncurative resection [P

Abstract Gastrointestinal stromal tumors (GISTs) are typically characterized by activating mutations of the KIT proto-oncogene receptor tyrosine kinase (KIT) or platelet-derived growth factor receptor alpha (PDGFRA). Recently, the neurotrophic tyrosine receptor kinase (NTRK) fusion was reported in a small subset of wild-type GIST. We examined trk IHC and NTRK gene expressions in GIST. Pan-trk immunohistochemistry (IHC) was positive in 25 (all 16 duodenal and 9 out of 16 small intestinal GISTs) of 139 cases, and all pan-trk positive cases showed diffuse and strong expression of c-kit. Interestingly, all of these cases showed only trkB but not trkA/trkC expression. Cap analysis of gene expression (CAGE) analysis identified increased number of genes whose promoters were activated in pan-trk/trkB positive GISTs. Imbalanced expression of NTRK2, which suggests the presence of NTRK2 fusion, was not observed in any of trkB positive GISTs, despite higher mRNA expression. TrkB expression was found in duodenal GISTs and more than half of small intestinal GISTs, and this subset of cases showed poor prognosis. However, there was not clear difference in clinical outcomes according to the trkB expression status in small intestinal GISTs. These findings may provide a possible hypothesis for trkB overexpression contributing to the tumorigenesis and aggressive clinical outcome in GISTs of duodenal origin.

Objectives: There are many surgical options for the treatment of rectal prolapse. To date, the efficacy of mesh-free laparoscopic suture rectopexy remains unclear due to the limited number of reports. This study aimed to evaluate the safety and efficacy of laparoscopic suture rectopexy. Methods: This observational cohort study is a retrospective cross-sectional analysis of a continuously maintained database. All patients underwent laparoscopic suture rectopexy for rectal prolapse between April 2012 and March 2018. The primary outcomes measured were recurrence rates and complications of laparoscopic suture rectopexy. Results: A total of 268 patients (29 male and 239 female) underwent laparoscopic suture rectopexy. Their mean age was 77 (19-95) years, and the mean prolapse length was 6.4 (3.5-20) cm. One patient suffered an intraabdominal abscess. Spondylitis developed in another patient following surgery. The median follow-up period was 45 (12-82) months. A total of 22 patients (8.2%) developed recurrence. The average time to recurrence was 15.6 (1-44) months. Multivariate analysis revealed a significant correlation between recurrence and prolapse length >7.0 cm (OR: 1.26, 95% CI: 1.38-1.42, P < 0.01). Conclusions: Laparoscopic suture rectopexy for complete rectal prolapse is a minimally invasive and safe procedure that may lead to lower recurrence rates.

ObjectiveThe aim of the study is to discuss the efficacy of live vs. remote cadaver surgical training (CST) for minimally invasive surgery (MIS).MethodsA cohort of 30 interns in their first and second years of training were divided into three groups: live observers (n = 12), live participants (n = 6), and remote observers: (n = 12). The interns had the opportunity to either observe or actively participate in two different surgical procedures, namely, laparoscopic lower anterior resection, performed by a colorectal surgical team, and laparoscopic fundoplication, performed by a pediatric surgical team. The procedures were conducted either at a base center or at a remote center affiliated with the institute. Some of the interns interacted directly with the surgical teams at the base center, and others interacted indirectly with the surgical teams from the remote center. All interns were administered questionnaires before and after completion of the CST in order to assess their understanding of various aspects related to the operating room layout/instruments (called “design”), accessing the surgical field (called “field”), understanding of anatomic relations (called “anatomy”), their skill of dissection (called “dissection”), ability to resolve procedural/technical problems (called “troubleshooting”), and their skill in planning surgery (called “planning”) according to their confidence to operate using the following scale: 1 = not confident to operate independently; 4 = confident to operate with a more senior trainee; 7 = confident to operate with a peer; and 10 = confident to operate with a less experienced trainee. A p

Cowden syndrome is characterized by several clinical features related to tumorous lesions primarily consisting of systemic hamartomas. The mutation of a tumor suppressor gene, the PTEN gene, is etiologically involved. As gastrointestinal lesions, polyps of all digestive tracts involving the esophagus to rectum develop. In patients with Cowden syndrome, the risk of colorectal cancer may increase. However, the characteristics of colorectal cancer in these patients remain to be clarified and sufficient findings regarding chemotherapy have not been obtained. A 39-year-old man was treated with a colonic stent for colitis obstructive due to circumferential transverse colon carcinoma. After decompression, elective extended laparoscopic right hemicolectomy was performed. Preoperative systemic detailed examination revealed characteristic dermal/mucosal findings, polyposis of the upper digestive tract, and a thyroid tumor. On PTEN gene sequencing, a mutation was detected at codon 130 of exon 5, leading to a diagnosis of Cowden syndrome. Postoperative adjuvant chemotherapy was performed for 6 months, but recurrent peritoneal dissemination was observed 1 month after its completion. FOLFOXIRI + bevacizumab therapy was started. Transiently, a partial response was achieved in peritoneally disseminated nodes according to the RECIST. There was no increase in the volume of cancerous ascites. However, an increase in the volume of ascites and local relapse were noted at the completion of the tenth course. The regimen was switched to FOLFIRI + panitumumab, but peritoneal dissemination exacerbated and the patient died 18 months after surgery.

Abstract Aim In Japan, we have not been able to validate the results of laparoscopic surgery for locally advanced rectal cancer using the universal index “circumferential resection margin (CRM).” Previously, we established a semi‐opened circular specimen processing method and validated its feasibility. In the PRODUCT trial, we aimed to assess CRM in patients with locally advanced rectal cancer who underwent laparoscopic rectal resection. Methods This was a multicenter, prospective, observational study. Eligible patients had histologically confirmed rectal adenocarcinoma located at or below 12 cm above the anal verge with clinical stage II or III and were scheduled for laparoscopic or robotic surgery. The primary endpoint was pathological CRM. CRM ≤1 mm was defined as positive. Results A total of 303 patients operated on between August 2018 and January 2020 were included in the primary analysis. The number of patients with clinical stage II and III was 139 and 164, respectively. Upfront surgery was performed for 213 patients and neoadjuvant therapy for 90 patients. The median CRM was 4.0 mm (IQR, 2.1‐8.0 mm), and CRM was positive in 26 cases (8.6%). Univariate and multivariate analyses demonstrated that a predicted CRM from the mesorectal fascia of ≤1 mm on MRI was the significant factor for positive CRM (P = .0012 and P = .0045, respectively). Conclusion This study showed the quality of laparoscopic rectal resection based on the CRM in Japan. Preoperative MRI is recommended for locally advanced rectal cancer to prevent CRM positivity.

Abstract Anal canal cancer (ACC) has been reported to be an uncommon cancer in Japan, as in the USA, Europe, and Australia. This retrospective multi‐institutional study was conducted to clarify the characteristics of ACC in Japan. First, the histological ACC type cases treated between 1991 and 2015 were collected. A detailed analysis of the characteristics of anal canal squamous cell carcinoma (SCC) cases was then conducted. The results of the histological types revealed that of the 1781 ACC cases, 435 cases (24.4%) including seven cases of adenosquamous cell carcinomas were SCC and 1260 cases (70.7%) were adenocarcinoma. However, the most common histological type reported in the USA, Europe, and Australia is SCC. Most ACC cases are adenocarcinomas and there is a low incidence of SCC in Japan which is different from the above‐mentioned countries. Moreover, we reclassified T4 into the following two groups based on tumor size: T4a (tumor diameter of 5 cm or less) and T4b (tumor diameter of more than 5 cm). The results of the TNM classification of SCC revealed that the hazard ratio (HR) to T1 of T2, T3, T4a, and T4b was 2.45, 2.28, 2.89, and 4.97, respectively. As T4b cases had a worse prognosis than T4a cases, we propose that T4 for anal canal SCC in Japan be subclassified into T4a and T4b.

Abstract We report a case in which analysis of copy number variation revealed local recurrence of submucosal invasive colorectal cancer after curative endoscopic submucosal dissection (ESD). An 86‐year‐old man with a history of abdominoperineal resection of the rectum for rectal cancer underwent resection with ESD for early‐stage sigmoid cancer 5 cm away from the stoma opening. At the same time, ileocecal resection was performed for advanced cecal cancer. Twelve months after ESD, advanced cancer occurred in the area of the ESD lesion. It was unclear if the cancer was a local recurrence after ESD, implantation of cecal cancer, or a new lesion. Copy number variation analysis performed for the three lesions revealed that the new lesion originated from residual tumor cells from ESD and was unlikely to be cecal cancer.

Abstract Background The efficacy of adjuvant chemotherapy for high-risk stage II colon cancer (CC) has not been well established. We compared the effects of surgery with and without oral uracil and tegafur plus leucovorin (UFT/LV) in patients with high-risk stage II CC, adjusting for potential risk factors. Methods We enrolled patients with histologically confirmed stage II colon adenocarcinoma with at least one of the following conditions: T4 disease, perforation/penetration, poorly differentiated adenocarcinoma/mucinous carcinoma, or

Intestinal endometriosis is a benign disease characterized by ectopic growth of the endometrium and causes extensive fibrosis and adhesions in response to repeated episodes of bleeding and inflammation with the menstrual cycle. We encountered a rare case of intestinal endometriosis that caused complete rectal obstruction in a 34-year-old woman undergoing infertility treatment. Colonoscopy showed rectal stenosis and obstruction but no evidence of a tumor. Bowel obstruction due to endometriosis was diagnosed based on the history and imaging findings. Transanal decompression was performed. Subsequent laparoscopic surgery revealed severe inflammation around both ovaries and a tumor-like rectal stenosis. Similar findings were obtained in the transverse colon and terminal ileum. We performed laparoscopic low anterior resection, partial transverse colon resection, ileocecal resection, bilateral cystectomy, and left salpingectomy. Infertility treatment was restarted and resulted in a successful term pregnancy. The patient remains well. Laparoscopic surgery, which has the advantage of being minimally invasive, allows for early postoperative recovery and discharge in patients with endometriosis; furthermore, the uterus and adnexa can be preserved due to the magnifying effect of the laparoscope. In this case, it was possible to resume infertility treatment. Intestinal endometriosis is a rare cause of bowel obstruction, but should be kept in mind if intestinal obstruction occurs during infertility treatment. Laparoscopic surgery may be useful for multiple endometriotic lesions and serve as a bridge to infertility treatment.

Background: Anti-epidermal growth factor receptor (EGFR) therapy has been identified to prolong the survival of metastatic colorectal cancer (mCRC) patients without RAS mutations. However, its efficacy is not always consistent for these patients. Genomic profiles of primary tumors and metastases are not always concordant; thus, chemotherapeutic agents can alter the tumor molecular profile. This molecular heterogeneity may explain resistance to anti-EGFR therapy. Liquid biopsy using circulating tumor DNA (ctDNA) is a novel, non-invasive diagnostic tool that can accommodate this molecular heterogeneity, providing a comprehensive, real-time view of the molecular landscape. In this study, we evaluated the predictive value of genomic mutations in ctDNA for primary and acquired resistance to anti-EGFR therapy. Methods/Design: This study is a prospective, multicenter, observational study of mCRC patients with wild-type tissue RAS treated with cytotoxic agents and anti-EGFR antibodies as first-line therapy. Genomic mutations, including RAS, BRAF, PIK3CA, and EGFR in ctDNA, are assessed via Droplet Digital PCR before starting chemotherapy and every 3 months thereafter until disease progression. The target sample size is estimated to be 100. The primary endpoint is the response rate in patients without RAS mutation in their blood sample before starting chemotherapy. Discussion: This study will clarify the predictive value of baseline RAS mutation in ctDNA for responses to anti-EGFR therapy; the frequency of emerging RAS, BRAF, PIK3CA, and EGFR mutations in ctDNA; and the association with secondary resistance to anti-EGFR therapy in first-line therapy for wild-type tissue RAS mCRC patients.

Abstract Background The American Society of Surgery and American Society for Surgical Infections issued guidelines for surgical site infections (SSIs) in December 2016. These guidelines recommend a purse-string suture (PSS) for stoma closure as it facilitates granulation and enables open wound drainage. This study investigated the effect of using negative pressure wound therapy (NPWT) along with standard PSS and aimed to determine the optimal period of NPWT use. Methods The patients were divided into three groups as follows: Group A, postoperative wound management alone with gauze exchange as the representative of conventional PSS; Group B, the performed management was similar to that of Group A plus NPWT for 1 week; and Group C, the performed management was similar to that of Group A plus NPWT for 2 weeks. Regarding objective measures, the wound reduction rate was the primary outcome, and the incidence of SSIs, length of hospital stay, and wound healing duration were the secondary outcomes. Results In total, 30 patients (male: 18, female: 12) were enrolled. The average age was 63 (range: 43–84) years. The wound reduction rate was significantly higher in Group B than in Group A on postoperative days (PODs) 7 (66.1 vs. 48.4%, p = 0.049) and 10 (78.6 vs. 58.2%, p = 0.011), whereas no significant difference was observed on POD 14. Compared with Group A, Group C (POD 7: 65.9%, POD 10: 69.2%) showed an increase in the wound reduction rate on POD 7, although the difference was not significant (p = 0.075). SSIs were observed in Groups B (n = 2) and C (n = 2) (20%) but not in Group A (0%). Conclusions The most effective duration of NPWT use for ileostomy closure with PSS in terms of the maximum wound reduction rate was from PODs 3 to 10. However, NPWT did not shorten the wound healing duration. NPWT may reduce the wound size but should be used with precautions for SSIs. The small sample size (30 cases), the use of only one type of NPWT system, and the fact that wound assessment was subjective and not blinded were the limitations of this study. Further studies are needed to confirm our findings. Trial registration: UMIN Clinical Trials Registry; UMIN000032174 (10/04/2018).

Learning is a crucial basis for biological systems to adapt to environments. Environments include various states or episodes, and episode-dependent learning is essential in adaptation to such complex situations. Here, we developed a model for learning a two-target search task used in primate physiological experiments. In the task, the agent is required to gaze one of the four presented light spots. Two neighboring spots are served as the correct target alternately, and the correct target pair is switched after a certain number of consecutive successes. In order for the agent to obtain rewards with a high probability, it is necessary to make decisions based on the actions and results of the previous two trials. Our previous work achieved this by using a dynamic state space. However, to learn a task that includes events such as fixation to the initial central spot, the model framework should be extended. For this purpose, here we propose a “history-in-episode architecture.” Specifically, we divide states into episodes and histories, and actions are selected based on the histories within each episode. When we compared the proposed model including the dynamic state space with the conventional SARSA method in the two-target search task, the former performed close to the theoretical optimum, while the latter never achieved target-pair switch because it had to re-learn each correct target each time. The reinforcement learning model including the proposed history-in-episode architecture and dynamic state scape enables episode-dependent learning and provides a basis for highly adaptable learning systems to complex environments.

Abstract Background Expansion of the indication for liver resection and new regimens for systemic chemotherapy have improved postoperative outcomes for synchronous colorectal liver metastases (CRLM). However, such cases can still have a high recurrence rate, even after curative resection. Therefore, there is a need for postoperative adjuvant chemotherapy (POAC) after liver resection in patients with CRLM. There are few studies of the efficacy of POAC with an oxaliplatin-based regimen after simultaneous resection for colorectal cancer and CRLM with curative intent. The goal of the study was to compare POAC with oxaliplatin-based and fluoropyrimidine regimens using propensity score (PS) matching analysis. Methods The subjects were 94 patients who received POAC after simultaneous resection for colorectal cancer and synchronous CRLM, and were enrolled retrospectively. The patients were placed in a L-OHP (+) group (POAC with an oxaliplatin-based regimen, n = 47) and a L-OHP (−) group (POAC with a fluoropyrimidine regimen, n = 47). Recurrence-free (RFS), cancer-specific (CSS), unresectable recurrence-free (URRFS), remnant liver recurrence-free (RLRFS), and extrahepatic recurrence-free (EHRFS) survival were analyzed. Results Before PS matching, the L-OHP (+) and (−) groups had no significant differences in RFS, CSS, URRFS, RLRFS, and EHRFS. Univariate analysis indicated significant differences in age, preoperative serum CEA (≤ 30.0 ng/mL/ > 30.0 ng/mL), differentiation of primary tumor (differentiated/undifferentiated), T classification (T1–3/T4), number of hepatic lesions and maximum diameter of the hepatic lesion between the L-OHP (+) and (−) groups. After PS matching using these confounders, RFS was significantly better among patients in the L-OHP (+) group compared with the L-OHP (−) group (HR 0.40, 95% CI 0.17–0.96, p = 0.04). In addition, there was a trend towards better RLRFS among patients in the L-OHP (+) group compared with the L-OHP (−) group (HR 0.42, 95% CI 0.17–1.02, p = 0.055). However, there were no significant differences in CSS, URRFS and EHRFS between the L-OHP (+) and (−) groups. Conclusions PS matching analysis demonstrated the efficacy of POAC with an oxaliplatin-based regimen in RFS and RLRFS.

Abstract Background Urothelial carcinoma arises from transitional cells in the urothelial tract. In advanced cases, it can metastasize locally to surrounding organs or distally to organs such as the lungs, bones, or liver. Here we describe a case of rectal metastasis from urothelial carcinoma treated with multiple sessions of transurethral resection of bladder tumor (TURBT). Case presentation A 72-year-old woman presented to our department with abdominal bloating andobstructed defecation. She had undergone two sessions of TURBT for early urothelial carcinoma in another hospital at 64 and 65 months ago, respectively. Cystoscopy at 3 months after the second TURBT session had indicated disease recurrence, and thus, she had been referred to our hospital for further examination, followed by TURBT for the third time at 59 months ago and for the fourth time at 48 months ago; thereafter, she had been followed up with cystoscopy every 6 months without any recurrence. However, she returned to our hospital, complaining of difficult defecation. Subsequent colonoscopy demonstrated an obstructive tumor in the rectum, which was pathologically diagnosed as metastatic urothelial carcinoma of the bladder. Laparoscopic examination revealed two small areas of peritoneal dissemination in the pelvis. A sigmoid colostomy was performed without rectal tumor resection. She has been receiving chemotherapy and is still alive 10 months after surgery. Conclusions Rectal metastasis is a rare site of metastasis for urothelial carcinomas. It is important to consider the possibility of annular rectal constriction caused by infiltrating or metastasizing urothelial carcinoma when managing patients with urothelial carcinoma and with difficult defecation.

Abstract Aim Appendicitis is divided into two categories: complicated appendicitis (CA) and uncomplicated appendicitis (UA). In pediatric patients with CA, the use of interval appendectomy (IA), which is non‐operative management followed by elective surgery, has decreased the number of postoperative complications. Before discussing the merit of IA for adult patients, we need to clarify whether the frequency and seriousness of the complication rate after emergency surgery is higher for CA than for UA. Methods This retrospective cohort study included adult patients who underwent appendectomy and who were registered in the National Clinical Database (NCD) from 2014 to 2016. Patients with CA who underwent emergency appendectomy comprised the CA group. Patients with UA comprised the UA group. Patients with chronic or recurrent appendicitis who underwent elective appendectomy comprised the elective appendectomy (EA) group. Primary outcomes were all morbidity, serious morbidity, and mortality within 30 days after appendectomy. Results We included 109 256 patients in the study: 14 798 CA, 86 876 UA, and 7582 EA patients. Compared with the UA group, the rates of all morbidity, serious morbidity, and mortality were significantly higher in the CA group. All morbidity, serious morbidity, and mortality rates were significantly lower in the EA group than in the other two groups. Conclusions We confirmed that emergency surgery for CA places the patient at relatively higher risk. We also showed that the risk associated with EA is significantly lower than that for the other methods.

An 81-year-old man was brought to our hospital due to a suspicion of left incarcerated femoral hernia. He was previously diagnosed with incarcerated left groin hernia and was treated using the mesh plug method 1 month back at another hospital. Abdominal computed tomography scan revealed small bowel obstruction, incarcerated bowel, and compression of the left femoral vein. Thus, the patient was diagnosed with incarcerated femoral hernia. An emergency laparoscopic surgery was then performed, and we found that the small bowel was incarcerated into the let femoral ring and was necrotic. However, there was no recurrence of left inguinal hernia. The small necrotic bowel was resected and the femoral ring was repaired. The patient was discharged 8 days after the surgery, and there was no recurrence of femoral hernia after 1 year.

Well-differentiated papillary mesothelioma (WDPM) is an uncommon mesothelial neoplasm, which is generally regarded as benign or indolent in terms of its clinical behavior. However, details about WDPM have remained relatively unknown. Therefore, in this study, we examined six incidentally detected cases of WDPM of the peritoneum. All six cases were surgically excised, without any additional therapeutic measures. None of the cases showed recurrence. All six cases presented single lesions and the tumor sizes ranged from 2 to 10 mm. Histologically, all six cases exhibited papillary proliferation of cytologically bland mesothelial cells with a fibroconnective tissue core. One of the cases (Case 6) presented small invasive foci in the stalk. The tumor cells were immunohistochemically positive for mesothelial markers and negative for GLUT-1, p53, and CD146. The Ki-67 labeling index of the tumor cells was lower than 5% at the hot spots. All samples were BAP1-positive. None of the samples presented p16 homozygous deletion, as assessed by fluorescence in situ hybridization (FISH). None of the patients deceased due to WDPM. However, in Case 3, death occurred due to pancreatic cancer. The results of this study indicate the importance of analyzing immunohistochemical markers and p16 status to diagnose WDPM accurately.

The lateral prefrontal cortex (LFPC) plays a crucial role in executive function by adaptively storing behavior-relevant information as working memory. Neural mechanisms associated with local field potentials (LFPs) may underlie the adaptive properties of the LFPC. Here, we analyzed how LFPs recorded from the monkey LFPC are modulated by the crucial factors of a shape manipulation task. In this task, the test shape is transformed by manipulating a lever to match the size and orientation of the sample shape. The subject is required to temporarily memorize the rules such as the arm-movement-manipulation relationship and the sample shape to generate the sequential behavior of operations. In the present study, we focused on task variables about shape and rules, and examined among which aspects distinguish the ventral and dorsal sides of the LFPC. We found that the transformed shape in the sample period strongly affected the theta and delta waves in the delay period on the ventral side, while the arm-manipulation assignment influenced the gamma components on the dorsal side. These findings suggest that area- and frequency-selective LFP modulations are involved in dynamically recruiting different behavior-relevant information in the LFPC.

Abstract Background Endosalpingiosis in the lymph nodes of the mesocolon is very rare. We reported a case with appendiceal endometriosis who had endosalpingiosis in the lymph nodes of the mesocolon that was found during laparoscopic ileocecal resection. Case presentation The patient was a 44-year-old woman who had visited a physician for fever, bloody stool, and abdominal pain 1 year earlier. She was diagnosed with ulcerative colitis on colonoscopy, and symptoms improved with oral treatment. A colonoscopy performed 2 months after diagnosis detected a hard, 20-mm submucosal tumor (SMT) in the cecum. On abdominal contrast CT, an intensely stained mass, including a low-density region, was observed in the cecum. A boring biopsy was performed after mucosal resection of the cecal SMT at our hospital, but diagnosis could not be made. Since the possibility of a malignant lesion could not be ruled out, laparoscopic ileocecal resection was performed. In the resected specimen, a 29 × 27 × 21-mm mass was present in the appendicular root. On histopathological examination, appendiceal endometriosis and endosalpingiosis in the lymph nodes around the ileocolic artery were observed. The postoperative course was favorable, and the patient was discharged 7 days after surgery. Conclusion Differentiation of endosalpingiosis in lymph nodes in the mesocolon from lymph node metastasis of adenocarcinoma is important in patients with an abdominal mass.

Abstract Background Robotic surgery for rectal cancer, which is now performed worldwide, can be associated with elevated creatine kinase levels postoperatively. In this study, we compared postoperative complications between patients undergoing robotic surgery and laparoscopic surgery. Methods We identified 66 consecutive patients who underwent curative resection for rectal cancer at Juntendo University Hospital between January 2016 and February 2019. Patients were divided into a conventional laparoscopic surgery (CLS) group (n = 38) and a robotic-assisted laparoscopic surgery (RALS) group (n = 28) before comparing various clinicodemographic factors between the groups. Results Patient age and gender, surgical approach (CLS/RALS), pathological T factor, pathological stage, duration of postoperative hospital stay, and postoperative complications were not significantly different between the RALS and CLS groups. However, the operation time was significantly longer in the RALS group (407 min) than in the CLS group (295 min; p

The real world is essentially an indefinite environment in which the probability space, i. e., what can happen, cannot be specified in advance. Conventional reinforcement learning models that learn under uncertain conditions are given the state space as prior knowledge. Here, we developed a reinforcement learning model with a dynamic state space and tested it on a two-target search task previously used for monkeys. In the task, two out of four neighboring spots were alternately correct, and the valid pair was switched after consecutive correct trials in the exploitation phase. The agent was required to find a new pair during the exploration phase, but it could not obtain the maximum reward by referring only to the single previous one trial; it needed to select an action based on the two previous trials. To adapt to this task structure without prior knowledge, the model expanded its state space so that it referred to more than one trial as the previous state, based on two explicit criteria for appropriateness of state expansion: experience saturation and decision uniqueness of action selection. The model not only performed comparably to the ideal model given prior knowledge of the task structure, but also performed well on a task that was not envisioned when the models were developed. Moreover, it learned how to search rationally without falling into the exploration–exploitation trade-off. For constructing a learning model that can adapt to an indefinite environment, the method of expanding the state space based on experience saturation and decision uniqueness of action selection used by our model is promising.

Enterocolic lymphocytic phlebitis is phlebitis of unknown etiology in which lymphocytes affect veins without arteries and shows evidence of systemic vasculitis in the intestinal wall and mesentery, mainly in the small intestine and colon. Although patients present with a variety of gastrointestinal symptoms and findings like those of inflammatory bowel disease or ischemic bowel disease, there are no specific findings for enterocolic lymphocytic phlebitis. As a result, a diagnosis tends to be made after surgery. There are few case reports of enterocolic lymphocytic phlebitis, and the impact of chronic courses and immunosuppressive drugs on enterocolic lymphocytic phlebitis is not well known. A 47-year-old man was treated with infliximab and steroids for unexplained ulceration and narrowing of the ileocecal area, which was suspected to be inflammatory bowel disease with atypical findings. Lymphocytic phlebitis was noted in the surgical specimen, and enterocolic lymphocytic phlebitis was diagnosed. No recurrence of enterocolic lymphocytic phlebitis was observed postoperatively. This disease should also be considered among patients with inflammatory bowel disease-like lesions that do not respond to infliximab or steroids.

Huge accessory spleen (AS) is a rare condition difficult to diagnose. We recently treated a Japanese woman with a progressive huge AS. She had a history of aortic valve replacement for aortic stenosis 1 month prior. At that time, a 4-cm AS had been detected by the preoperative computed tomography (CT). This mass was a progressive tumor which grew to 7 cm over the course of 3 months. Thus, we performed surgery with a preoperative diagnosis of huge AS by CT and positron emission tomography. A laparoscopic resection was performed considering the risk of torsion, spontaneous rupture, or hemorrhage. The final pathological diagnosis was AS. This is the first reported case in the English literature of progressive AS with no symptoms at the initial presentation that was treated with laparoscopic resection.

Inflammatory fibroid polyp (IFP) is a rare and benign tumor of the gastrointestinal (GI) tract that harbors PDGFRA mutations. PDGFRA alterations are also found in subsets of other GI tract mesenchymal tumors, such as KIT-negative gastrointestinal stromal tumors and inflammatory myofibroblastic tumors. We report a case of ileal IFP with uncommon histological features. A 71-year-old woman was referred to our hospital with abdominal pain. She was diagnosed with intestinal intussusception. Laparoscopic surgery was performed and the ileum was resected by 50 cm. Microscopically, tumor cells with round nuclei and prominent nucleoli proliferating within the collagenous fibrous stroma were observed. Some spindle-shaped cells and lymphoplasmacytic infiltrations were also observed, and eosinophils were scattered throughout the lesion. Lymphovascular structures of various sizes were prominent in the stroma. Immunohistochemistry revealed PDGFRA overexpression but did not show positive staining for CD34. The tumor had a heterozygous deletion of five amino acids in exon 12 (del 1696-1710, Δ566-570) of PDGFRA. Based on these findings, a diagnosis of IFP was made. The patient remains alive without any evidence of recurrence.

Background/Aims Sclerotherapy with aluminum potassium sulfate and tannic acid (ALTA) has a potent effect on internal hemorrhoids. In this retrospective study, we compared the effects of endoscopic ALTA therapy and standard ALTA therapy. Methods We investigated patients who underwent treatment for internal hemorrhoids at our institution between 2014 and 2016. They were divided into a standard ALTA group (n=33, treated using proctoscopy) and an endoscopic ALTA group (n=48). We compared the clinical findings between the 2 groups. Results There were no intergroup differences in background factors. The mean ALTA dose was 21.9±7.2 mL and 17.8±3.4 mL in the standard and endoscopic ALTA groups, respectively (p

Background: Treatment with TAS-102 has significantly improved the progression-free survival (PFS) and overall survival (OS) of patients with metastatic colorectal cancer (mCRC). Reportedly, the combination of TAS-102 plus bevacizumab extends the median PFS. The present study aimed to confirm the efficacy and safety of TAS-102 plus bevacizumab (biweekly administration) as third-line chemotherapy for patients with mCRC. Methods/Design: This is a single-arm, open-label, prospective, nonrandomized, multicenter phase II trial conducted in Japan. With a threshold and expected PFS of 2.1 and 3.5 months, respectively, the simulation results showed a sample size of 42 with α = 0.05 (both sides) for 90% power, based on the One-Arm Binomial test using the SWOG statistical tool. If the estimated dropout is 7%-8%, the target sample size is estimated to be 45. The TAS-CC4 study regimen comprised 28-day cycles with biweekly oral administration of TAS-102 (35 mg/m2 twice daily on days 1-5 and 15-19 of every 28-day cycle) and bevacizumab (5.0 mg/kg on days 1 and 15). The primary end point is the PFS; secondary end points include response rate (RR), OS, grade 3 neutropenia, and genetic alterations (KRAS/BRAF mutations) in the circulating cell-free DNA. Discussion: The present study can contribute to the determination of the effective dosing interval of TAS-102 and bevacizumab in patients with mCRC and is thought to lead to prophylaxis of neutropenia and prolongation of the treatment period.

Munchausen syndrome is a rare type of mental disorder in which the patient fakes illness to gain attention and sympathy. Patients may lie about symptoms, make themselves appear sick, or make themselves purposely unwell. We describe a case of repeated enterocutaneous fistula in Munchausen syndrome. A 53-year-old Japanese male was admitted to our hospital for the treatment of a high-flow enterocutaneous fistula. Surgery was performed two times, but the fistula recurred each time. Chopsticks with blood on them were coincidentally detected in the trash in the patient’s room. It was revealed that the enterocutaneous fistula was caused by self-mutilation. A psychiatrist was consulted, and the patient was diagnosed with Munchausen syndrome. The psychiatrist initiated treatment and the patient admitted the self-harm. His prolonged wound site was closed and he was able to be discharged. There has been no recurrence of the self-harm as of this writing, 3 years later. The treatment of Munchausen syndrome is difficult and early detection is important.

Pigmented breast cancer in the skin caused by nonneoplastic melanocytes of epidermal origin is a rare condition of metastasis from breast cancer, but the pathogenesis of this phenomenon is almost unknown. In this report, we describe a case of breast cancer metastasis in the skin with prominent hyperkeratotic pigmentation caused by nonneoplastic melanocyte colonization. Immunohistochemical staining revealed that the metastatic tumor cells produced IL-23, which is reported not only to induce IL-17 but also to inhibit cell apoptosis in breast cancer cells, which affects tumor progression. In addition to IL-23, substantial numbers of IL-17-producing cells were detected at the peritumoral area, suggesting that IL-17 might induce not only melanogenesis but also keratinocyte proliferation and tumorigenesis. Our report suggests possible mechanisms of hyperkeratotic pigmentation of breast cancer metastasis in the skin.

Superior mesenteric artery syndrome (SMAS) is a relatively rare disease that involves bowel obstruction symptoms, such as vomiting and gastric distension, owing to the compression of the third portion of the duodenum from the front by the superior mesenteric artery (SMA) and from the rear by the abdominal aorta and the spine. SMAS is diagnosed on the basis of an upper gastrointestinal examination series indicating the obstruction of the third portion of the duodenum or a computed tomography scan indicating the narrowing of the branch angle between the aorta and the SMA (i.e., the aorta-SMA angle). Here, we report the case of a 78-year-old woman diagnosed with SMAS after a laparoscopic right hemicolectomy for cecal cancer, whose condition was improved by enteral nutritional therapy. We used her controlling nutritional status (CONUT) score as a nutrition assessment and noted the changes in the aorta-SMA angle over the course of the disease. This patient appeared to develop SMAS, on the basis of a worsened CONUT score and a decreased aorta-SMA angle, owing to the inflammation resulting from the intraoperative dissection of the tissues around the SMA and prolonged postoperative fasting. After the initiation of enteral nutritional therapy, the patient exhibited body weight gain and an improved aorta-SMA angle and CONUT score. Hence, assessment of the aorta-SMA angle and CONUT score is an important preoperative consideration.

Objectives: Temporary ileostomy is used to decrease morbidity from anastomotic leakages (ALs). However, ileostomies are associated with complications (i.e., stoma-related complications; SRCs), ileus due to stenosis, dehydration, and the need for a second operation. Here we retrospectively evaluated the impact of SRCs on the treatment of rectal cancer. Methods: We identified 180 consecutive patients who underwent curative resection for rectal cancer at Juntendo University Hospital between January 2006 and December 2014. We divided the patients into groups with and without defunctioning stoma (DS), and we compared the patient age and gender, tumor location, approach (laparotomy/laparoscopy), surgical procedure, distance of the tumor from the margin of the anus, T factor, stage, duration of postoperative hospital stay, and postoperative complications between these groups. Univariate and multivariate analyses were performed to determine the risk factors for postoperative hospital stay. Results: The symptomatic leakage rate in the DS group (n = 92) was not significantly different from that of the non-DS group (n = 88; p = 0.29). However, Grade 4 AL occurred significantly less frequently in the DS group (0%) than in the non-DS group (5.7%; p = 0.02). SRCs occurred in 14 DS-group patients (15.2%). The multivariate analysis demonstrated that both AL (odds ratio [OR] 9.24; confidence interval [CI] 4.91-19.4) and SRC (OR 1.84; CI 1.03-3.54) were independently predictive of short-term outcomes. Conclusions: The benefit of a DS is balanced against the risk of leakage and SRCs at rectal resection. Surgeons should focus on not only the consequences of AL, but also SRC risk.

The use of laparoscopic surgery is widespread worldwide and is becoming the standard procedure. Postoperative adhesion, which is one of the typical postoperative complications, is considered to be less likely to occur compared with open surgery. However, once complications, such as small bowel obstruction or chronic abdominal pain, occur due to adhesion, the minimal invasiveness can be greatly impaired, and it can also become costly from a medical economics perspective. In the past, anti-adhesion absorption barrier films have been used to prevent adhesion, but there are many cases in which laparoscopic techniques are required, depending on the site of intraperitoneal attachment. Herein, we report a device that can easily attach an absorbent barrier preparation.

A 76-year-old male underwent endoscopic mucosal resection for a stage T1 tumour of the sigmoid colon. We performed laparoscopic sigmoidectomy through 5 ports using needlescopic instruments. The resected specimen was extracted from the abdominal cavity transanally. After attaching an anvil to the sigmoidal stump, the rectal stump was reclosed using an endoscopic linear stapler, and then, colorectal anastomosis was conducted using the double stapling technique. Performing transanal specimen extraction using needlescopic forceps improves aesthetic outcomes and reduces post-operative pain and the risk of abdominal incisional hernias. This method is an easy to introduce a form of reduced-port surgery because of its feasibility and conventional port arrangement. Hence, we consider that it is an option for minimally invasive surgery.

Here, we report a case of repeated laparoscopic resection of extra-regional lymph node metastases in a patient after laparoscopic surgery for rectal cancer. A 72-year-old woman was diagnosed with upper rectal cancer and underwent laparoscopic low anterior resection and D3 dissection. The pathological stage was considered as T3, N2b, M0, Stage IIIC. Six months after the operation, positron emission tomography-computed tomography (PET-CT) showed fluorodeoxyglucose (FDG) accumulation in the infra-renal para-aortic lymph nodes (PALNs). Systemic chemotherapy was administered; however, chemotherapy was discontinued due to hemoptysis related to her pulmonary disease. Therefore, we performed laparoscopic PALN resection. Pathologically, one lymph node was diagnosed with a metastasis. Three months after the second operation, PET-CT identified FDG accumulation in the left lateral pelvic lymph nodes (LPLNs) and a PALN. Laparoscopic LPLN dissection and PALN resection through minilaparotomy were performed. Pathologically, lymph node metastases were diagnosed in both fields. Sixteen months after the 3rd operation, there is no recurrence.

The mitral valve morphology in patients with pectus excavatum (PE) has not been fully investigated. Thirty-five patients with PE, 46 normal controls, and patients with hypertrophic cardiomyopathy (HCM) who underwent 2 leaflet length measurements of Carpentier classification P2 and A2 using a transthoracic echocardiography were retrospectively investigated. The coaptation lengths and depths, papillary muscle tethering length, and mitral annular diameters were also measured. The P2 and A2 lengths were separately compared between 2 groups: older than 16 years and 16 years or younger. Furthermore, the correlations between actual P2 or A2 lengths and Haller computed tomography index, an index of chest deformity, were investigated in patients with PE exclusively. Among subjects older than 16 years, patients with PE had significantly shorter P2, longer A2, shorter copatation depth, and longer papillary muscle tethering length compared with normal controls. Similarly, patients with PE had significantly shorter P2 and shorter coaptation depth even compared with patients with HCM, while no significant difference was found in A2 length and papillary muscle tethering length. The same tendency was noted between 4 normal controls and 7 age- and sex-matched patients with PE ≤ 16 years old. No significant difference regarding A2/P2 ratio was found between patients with PE older and younger than 16 years. No significant correlation between the Haller computed tomography index and actual mitral leaflet lengths in patients with PE older than 16 years was noted; the same was observed for A2/P2 in all patients with PE. In conclusion, the characteristic features of the shorter posterior mitral leaflet, the longer anterior mitral leaflet, the shorter coaptation depth, and the longer papillary muscle tethering length in patients with PE was demonstrated. This finding might provide a clue regarding the etiology of mitral valve prolapse in PE at its possible earliest form.

Purpose. The goal of this retrospective study was to identify prognostic factors associated with mortality after surgery for colorectal perforation among patients with connective tissue disease (CTD) and to review postoperative outcomes based on these prognostic factors. Methods. The subjects were 105 patients (CTD group: n=26, 24.8%; non-CTD group: n=79, 75.2%) who underwent surgery for colorectal perforation at our department. Cases with iatrogenic perforation due to colonoscopic examination were excluded from the study. We retrospectively investigated perioperative clinicopathological factors in patients undergoing surgery for colorectal perforation. Results. There were 7 patients (6.7%) who died within 28 days after surgery in all patients. In multivariate analysis, CTD and fecal peritonitis emerged as significant independent prognostic factors (p=0.005, odds ratio=12.39; p=0.04, odds ratio=7.10, respectively). There were 5 patients (19.2%) who died within 28 days after surgery in the CTD group. In multivariate analysis, fecal peritonitis emerged as a significant independent prognostic factor in the CTD group (p=0.03, odds ratio=31.96). The cumulative survival curve in the CTD group was significantly worse than that in the non-CTD group (p=0.006). An analysis based on the presence of fecal peritonitis indicated no significant difference in cumulative survival curves for patients without fecal peritonitis in the CTD and non-CTD groups (p=0.55) but a significant difference in these curves for patients with fecal peritonitis in the two groups (p

An amendment to this paper has been published and can be accessed via the original article.

A 73-year-old male underwent transurethral resection of a bladder tumor in August 2010 and April 2011. Pathological examination revealed urothelial carcinoma. After the surgery, chemotherapy and intravesical Bacillus Calmette-Guerin instillation were performed. In September 2014, he once again underwent transurethral resection of the bladder tumor for recurrence, and was again diagnosed with urothelial carcinoma, pT2, by pathological examination. After neoadjuvant chemotherapy, radical cystectomy for tumor recurrence was performed. Pathological examination at this time revealed small cell carcinoma, pT3N0. It is rare for urothelial carcinoma to change to small cell carcinoma, and the mechanism and cause of this change are still unknown. In this case report, we discuss what causes small cell carcinoma of the urinary bladder and review the literature regarding its origin.

Generally, lesions of rectal neuroendocrine tumors (NETs) 10 mm or smaller are less malignant and are indicated for endoscopic therapy. However, the vertical margin may remain positive after conventional endoscopic mucosal resection (EMR) because NETs develop in a way similar to submucosal tumors (SMTs). The usefulness of EMR with a ligation device, which is modified EMR, and endoscopic submucosal dissection (ESD) was reported, but no standard treatment has been established. We encountered 2 patients in whom rectal NETs were completely resected by combined dissection and resection of the circular muscle layer using the ESD technique. Case 1 was an 8-mm NET of the lower rectum. Case 2 was NET of the lower rectum treated with additional resection for a positive vertical margin after EMR. In both cases, the circular muscle layer was dissected applying the conventional ESD technique, followed by en bloc resection while conserving the longitudinal muscle layer. No problems occurred in the postoperative course in either case. Rectal NETs are observed in the lower rectum in many cases, and it is less likely that intestinal perforation by endoscopic therapy causes peritonitis. The method employed in these cases, namely combined dissection and resection of the circular muscle layer using the ESD technique, can be performed relatively safely, and it is possible to ensure negativity of the vertical margin. In addition, it may also be useful for additional treatment of cases with a positive vertical margin after EMR.

Endoscopic unroofing is effective for treating large colonic lipomas. However, additional endoscopic resection is occasionally required when the outcomes of initial unroofing are incomplete. The colonoscopy of an 82-year-old woman with abdominal pain revealed a yellowish lipoma of about 20 mm in the transverse colon. The mass was treated by unroofing, but a follow-up colonoscopy 5 days later revealed residual lipoma. One month later, the regenerated surface had become covered with mucosa, and the status of the lipoma had returned to that before unroofing. The colonoscopy of a 74-year-old man with abdominal pain and melena revealed a 50-mm-wide protruding lipoma in the transverse colon. The mucosa of the upper third of the lipoma was excised using an electric knife and snare, which allowed the immediate partial drainage of adipose tissue. Unroofing proceeded, but 7 days later, the unroofed surface had become coated with a white substance, and the residual lipoma required additional endoscopic resection. Colonic lipomas are often asymptomatic. However, patients with abdominal pain and hemorrhage should be treated in consideration of complete resection, but not by unroofing, which could leave a residual tumor. Drainage should be confirmed after unroofing and any residual lipoma should be treated by additional resection.

Positron emission tomography/computed tomography (PET/CT) is a credible diagnostic modality for detecting primary and metastatic malignancy. PET/CT sometimes shows false positives and negatives, which make clinical diagnosis difficult. A 42-year-old man who had undergone right upper lobectomy for lung cancer 1 year previously had PET/CT for a metastatic survey of the lung. The lung cancer was stage IB (pT2N0M0) bronchioloalveolar carcinoma. PET/CT showed massive 18F-fluorodeoxyglucose (FDG) uptake in the mesenteric lymph nodes. Because the mesentery is an unusual site of metastasis, the patient was under watchful observation. Another PET/CT after 6 months still showed FDG uptake in the same location, with a slightly increased standard uptake value. A systemic survey was performed, but it did not reveal any malignancies or inflammatory diseases. Eventually, the patient underwent probing laparoscopic surgery. For complete resection of the lymph nodes, laparoscopic ileocecal resection was performed. Histologically, the resected lymph nodes showed reactive lymphadenitis. Glucose transporter 1 immunostainings of the lung cancer and the lymph node were positive and partially positive, respectively. Although PET/CT is a powerful diagnostic modality, clinical interpretation of unusual results is difficult.

A 76-year-old woman with muscle ache, weakness of the extremities, and skin rash was diagnosed with dermatomyositis (DM). Upon the diagnosis of DM, a systemic survey of malignancy revealed an advanced carcinoma of the ascending colon. The patient underwent right hemicolectomy approximately 2 months after the onset of DM. The symptoms and signs of DM disappeared after the surgery without additional therapy. DM is an idiopathic systemic inflammatory disease characterized by muscle ache, muscle weakness, and skin rash. In some cases, DM develops as paraneoplastic syndrome, and it is assumed that 30% of DM patients have cancer. Symptoms and signs of DM can be attenuated by treatment of the malignancy, and they reappear if the malignancy recurs. It is essential to perform a systemic survey of malignancy in DM patients, and treatment of the malignancy has to precede treatment of DM.

An 81-year-old female consulted a local physician due to diarrhea. Since general fatigue and body weight loss were observed, she was admitted for detailed examination and treatment. Colonoscopy revealed a circumferential giant tumor with a maximum diameter of 10 cm in the rectum, and biopsy findings indicated villous adenoma. The tumor secreted a large amount of mucus, and a diagnosis of electrolyte depletion syndrome causing electrolyte disorders was made. We performed endoscopic submucosal dissection (ESD) as a less invasive procedure. The tumor was so big that the procedure had to be completed in two separate steps and it took 1,381 min in total. The tumor was histologically diagnosed as well-differentiated adenocarcinoma in high-grade adenoma located in the lower to upper rectum, invading into the mucosa without lymphatic or venous invasion. The stump of the resected specimen was negative for adenocarcinoma, however the horizontal stump was positive for adenoma. We administered steroid suppositories to prevent stenosis. After ESD, general fatigue and diarrhea disappeared and electrolyte disorders resolved. The patient had good clinical outcome without recurrence or stenosis.

Capsule endoscopy (CE) is commonly used for examining and diagnosing gastrointestinal disease, especially small bowel disease. Capsule retention is a well-known and significant complication of CE and requires surgical or endoscopic removal. Most reports described the retrieval of retained CE via laparotomy. We report a case of successful retrieval of the capsule using single incision laparoscopic surgery.

Intersphincteric resection (ISR) is a procedure designed to preserve anal function in cases with very low rectal cancer. We report our clinical experience with laparoscopic ISR (Lap ISR) performed using needlescopic instruments. First, a camera port is created at the umbilicus. Two 5-mm ports are then inserted at the right upper and lower quadrants. Two needlescopic forceps (Endo-Relief™ Hope Denshi Co., Chiba, Japan) are inserted at the left upper and lower quadrants. We then perform the following procedures; ligation of the inferior mesenteric artery and vein, total mesorectal excision and dissection of the intersphincteric space. After the transanal intersphincteric dissection, the specimen is extracted through the anus and a hand -sewn coloanal anastomosis is performed. The covering ileostomy is finally created at the right upper port. We performed Lap ISR using needlescopic forceps in two patients with very low rectal cancer. In both cases, we were able to perform this procedure without insertion of an additional port or to change the needlescopic forceps to conventional 5-mm forceps. Lap ISR with needlescopic instruments is a feasible procedure for minimally invasive surgery.

The patient was a 68-year-old man who was admitted to our hospital with a liver tumor. Abdominal ultrasonography and computed tomography revealed a liver tumor 30 mm in diameter. On colonoscopy, a pedunculated tumor with a central depression (20 mm in diameter) was observed in the ascending colon, and this tumor was considered to be invading deeply into the submucosal layer. Right hemicolectomy with D3 lymphadenectomy and partial hepatectomy were performed simultaneously. On histopathological examination of the resected specimen, the tumor was a well-differentiated tubular adenocarcinoma with 3,000 μm invasion of the submucosal layer. The liver tumor showed histological findings similar to those of the primary colorectal carcinoma. The pathological stage according to the 7th edition of the TNM classification was stage IV (T1N0M1). Nine months after the operation, computed tomography revealed hepatic hilar lymph node metastases and a great deal of ascites. The patient ultimately died 14 months after the operation.