Strangulated bowel obstruction caused by an ileo-ileal knot: a rare case report.

BACKGROUND: Intestinal knot formation is a condition wherein two segments of the intestine are knotted together; however, reports of small-intestinal ileo-ileal knot formation are rare. CASE PRESENTATION: The patient was a 62-year-old Asian male with a history of endoscopic colorectal adenoma resection and a spontaneous pneumothorax. The patient had no history of a laparotomy. He consulted his local doctor with the chief complaint of abdominal pain and was admitted to our hospital with suspicion of an acute abdomen. The abdomen had muscular guarding with tenderness and rebound tenderness. Contrast-enhanced computed tomography (CT) showed torsion of the mesentery of the small intestine with poor contrast filling. The patient was referred to our department with strangulated bowel obstruction and underwent an emergency laparotomy. Intraoperative findings revealed that two segments of the ileum were wrapped around each other to form a knot, and the strangulated small bowel was necrotic. After the release of the knot, partial resection of the small intestine was performed from 220 cm distal to the ligament of Treitz to 80 cm proximal to the cecum. The patient had a good postoperative course and was discharged on the 11th postoperative day. CONCLUSION: Ileo-ileal knots should be considered as part of the differential diagnosis when treating strangulated bowel obstruction.

Three-dimensional analysis of perineural invasion in extrahepatic cholangiocarcinoma using tissue clearing.

Perineural invasion (PNI) is a characteristic invasion pattern of distal cholangiocarcinoma (DCC). Conventional histopathologic examination is a challenging approach to analyze the spatial relationship between cancer and neural tissue in full-thickness bile duct specimens. Therefore, we used a tissue clearing method to examine PNI in DCC with three-dimensional (3D) structural analysis. The immunolabeling-enabled 3D imaging of solvent-cleared organs method was performed to examine 20 DCC specimens from five patients and 8 non-neoplastic bile duct specimens from two controls. The bile duct epithelium and neural tissue were labeled with CK19 and S100 antibodies, respectively. Two-dimensional hematoxylin/eosin staining revealed only PNI around thick nerve fibers in the deep layer of the bile duct, whereas PNI was not identified in the superficial layer. 3D analysis revealed that the parts of DCC closer to the mucosa exhibited more nerves than the normal bile duct. The nerve fibers were continuously branched and connected with thick nerve fibers in the deep layer of the bile duct. DCC formed a tubular structure invading from the epithelium and extending around thin nerve fibers in the superficial layer. DCC exhibited continuous infiltration around the thick nerve fibers in the deep layer. This is the first study using a tissue clearing method to examine the PNI of DCC, providing new insights into the underlying mechanisms.

[Short Term and Long Term Outcomes of Robotic Surgery in Sphincter Function Preserving Surgery for Lower Rectal Cancer].

BACKGROUND: Surgical and oncological outcomes of lower rectal cancer remain unsatisfactory. We investigated the short term and long term outcomes of robotic surgery for sphincter function-preserving surgery(SPS)for lower rectal cancer. METHOD: 433 lower rectal cancer patients who underwent SPS at our institution from January 2000 to July 2021 were included, excluding Stage Ⅳ cases and patients with multiple cancers. There were 288 cases of laparotomy, 81 cases of laparoscopic surgery, and 64 cases of robotic surgery; we abbreviated the group names as: OP, LAP, and R, respectively. We retrospectively reviewed the anastomotic leakage rate and prognosis of these groups. RESULTS: The anastomotic leakage rate was 23.6% in the OP group, 17.3% in the LAP group, and 6.3% in the R group, with a significant difference between the OP group and the R group. The 3-year recurrence free survival rate was 86.7% in the LAP group and 95.6% in the R group. Although there was no significant difference, the prognosis tended to be better in the R group. Local recurrence was observed in 3 patients in the LAP group and 1 patient in the R group. CONCLUSION: In SPS for advanced lower rectal cancer, robotic surgery may contribute to a reduction in anastomotic leakage.

Use of time­density curves of dynamic contrast­enhanced computed tomography for determination of the histological therapeutic effects of neoadjuvant chemotherapy for pancreatic ductal adenocarcinoma.

The present study aimed to investigate the histological changes caused by neoadjuvant chemotherapy (NAC) for pancreatic ductal adenocarcinoma (PDAC), and to demonstrate the use of time­density curves (TDCs) of dynamic contrast­enhanced computed tomography (CECT) for determination of the histological therapeutic effects of NAC for PDAC. A total of 96 patients with PDAC were examined; 46 underwent NAC (NAC group) and 50 did not undergo NAC (non­NAC group). Based on histological therapeutic effect and using the area of residual tumor (ART) grading system, the NAC group was divided into low­responders and high­responders. Histological analysis was used to evaluate the densities of cancer cells, cancer­associated fibroblasts (CAFs), microvessels and stromal collagen fibers in the NAC and non­NAC groups. Radiological analysis was used to evaluate the TDCs of three slopes of the NAC group, namely slopes between the non­contrast and arterial phases (δ1 and δ1'), between the arterial and portal phases (δ2 and δ2'), and between the portal and equilibrium phases (δ3 and δ3'). δ1­Î´3 were before NAC, whereas δ1'­Î´3' were after NAC. Changes in δ1, δ2 and δ3 before and after NAC were denoted as δδ1 (=δ1'­Î´1), δδ2 (=δ2'­Î´2) and δδ3 (=δ3'­Î´3). ART grading system, histological examination and radiological examination data were also statistically analyzed. Histological examination revealed a significant decrease in cancer cells and CAFs, and a significant increase in stromal collagen fibers due to NAC (P<0.01). Radiological examination revealed that δ1' was significantly higher than δ1 in low­responders (P<0.05), whereas δ2' was significantly lower than δ2 in high­responders (P<0.01). δδ2 was significantly lower and δδ3 was significantly higher in high­responders than in low­responders (P<0.01 and P<0.05, respectively). Receiver operating characteristic curve showed that δδ2 and δδ3 were effective indicators of the histological therapeutic effect of NAC. In conclusion, the TDC of dynamic CECT may be useful for determining the histological therapeutic effect of NAC for PDAC.

[A Case of Double Cancer of Squamous Cell Carcinoma of the Rectum and Adenocarcinoma of the Sigmoid Colon].

A 72-year-old male was transported to our hospital with complaints of heart palpitations and dyspnea since a month earlier and was immobile. Blood examination showed severe anemia, and colonoscopy revealed circumferential tumors in the rectum and the sigmoid colon. Histopathologic examination revealed the tumors as squamous cell carcinoma of the rectum and adenocarcinoma of the sigmoid colon. Therefore, they were diagnosed as double colorectal cancers. CT and MRI showed that rectal cancer invaded the seminal vesicles and the prostate; therefore, the patient underwent neoadjuvant chemoradiotherapy(oral capecitabine and concomitant radiation therapy: a total dose of 50.4 Gy/28 Fr)followed by total pelvic exenteration. Subsequent specimen pathology revealed a tumor regression grading of Grade 2 for the rectal and sigmoid colon cancers, and both were staged as ypT3N0M0, ypStage Ⅱa. Herein, we report a rare case of double cancer of adenocarcinoma of the sigmoid colon and squamous cell carcinoma of the rectum with a literature review.

[Treatment Strategy for Stage â £ Rectal Cancer Considering Local Treatment Outcomes].

We investigated 36 patients with Stage Ⅳ rectal cancer who underwent primary resection in our department between November 2015 and June 2020. Tumor localization was upper in 20 cases and lower in 16 cases. Six patients had the cT4b stage at initial diagnosis, and lateral lymph node metastases were detected in 6 cases. Preoperative treatment consisted of doublet chemotherapy in 20 cases, in combination with bevacizumab in 17 cases. Surgery for distant metastases was performed in 21 patients, and the final results were curative(Cur B)in 20 patients and palliative(Cur C)in 16 patients. Perioperative mortality was observed only in Cur C patients(5.6%). The local R1 resection rates in Cur B and Cur C patients were 10.0% and 18.8%, respectively, and the corresponding local RM≤1 mm rates were 55.0% and 43.8%. Additionally, the local recurrence rates were 25.0% and 0%, and the 3-year OS rates were 80.9% and 25.5%, respectively, in Cur B and Cur C patients. In Cur B, the local RM≤1 mm rates in the preoperative and non-preoperative treatment groups were 38.5% and 85.7%, respectively, and the corresponding local R1 resection rates were 7.7% and 14.3%. Additionally, the 3-year local recurrence-free survival rates were 68.2% and 66.7% and the 3-year OS rates were 82.1% and 80.0%, respectively, in the preoperative and non-preoperative treatment groups. We determined that preoperative chemotherapy alone is not sufficient for the local treatment of Stage Ⅳ rectal cancer, and concomitant preoperative radiotherapy should be considered. The prognosis of patients with Cur C is poor, and surgery-related deaths have been observed, which can be a problem for the palliative resection strategy.

[A Case of Descending Colon and Rectal Cancer with Acute Myeloid Leukemia Performed Robot‒Assisted Hartmann's Procedure].

The case is a 68‒year‒old male, who had been diagnosed with acute myeloid leukemia(AML)prior to rectal cancer surgery, was referred to our hospital for treatment in July 2019. We planned to treat the AML first, and then the colorectal cancer. After completion of 1 course of CAG therapy(cytarabine, aclarubicin, G‒CSF), his white blood cell count increased sufficiently, so he underwent a robot‒assisted Hartmann operation in October. A second course of CAG therapy was started 15 days postoperatively. However, he was then diagnosed with exacerbation of the AML; remission induction therapy (daunorubicin, cytarabine)was started in November. In December, he developed a fever and abdominal pain, and on CT scan, it was discovered that an abscess had formed around the rectal resection site. Myelosuppression from AML led to prolonged sepsis; and by January 2020, the sepsis was systemic. His actual cause of death was given as circulatory failure. We report this, because only a few cases on the treatment of overlapping AML and colorectal cancers can be found in the literature.

[Short-Term Results of Robot-Assisted Surgery in Patients Undergoing Neoadjuvant Chemotherapy for Rectal Cancer].

The advantages of robot-assisted surgery include: stable deployment of the robotic arm that enables excellent radical cure characteristics and preservation of function; the ability to perform precise surgery even in patients in whom performing laparoscopic surgery is difficult, such as those with pelvic or bulky tumors. However, there have been some reports on such issues as an increase in the incidence of postoperative complications and an increase in postoperative hospital stay in patients who underwent neoadjuvant chemotherapy(NAC); thus, we summarized and are reporting the short-term results of our experience in patients seen in our department to date. A total of 76 patients with rectal cancer who underwent robot-assisted surgery, and short-term postoperative results were compared between patients who underwent neoadjuvant chemotherapy (NAC group)and those who did not undergo neoadjuvant chemotherapy(non-NAC group). Of the 76 patients, 59 (77.6%)were male and 17(22.4%)were female, and 27(35.5%)in the NAC group. In the comparisons between the NAC and non-NAC groups, although the difference in operative time(523.5 vs 317.5 minutes, p<0.01)was significant, there were no significant differences in any of blood loss(59 vs 20g, p=0.22), postoperative hospital stay(14 vs 13 days: p=0.07), and onset of complications that were Clavien-Dindo Grade Ⅲa or higher(2 vs 1 patients, p=0.82). Robot- assisted surgery after NAC for rectal cancer was considered to be safe and very useful.

Short-term outcomes of robotic-assisted laparoscopic versus laparoscopic lateral lymph node dissection for advanced lower rectal cancer.

BACKGROUND: Therapeutic strategies to suppress local recurrence, including lateral lymph node metastasis, are important to improve the curability of rectal cancer. The aim of the present study was to clarify the advantages of robotic-assisted laparoscopic lateral lymph node dissection (RALLD), comparing its short-term outcomes with those of laparoscopic lateral lymph node dissection (LLLD). There are some retrospective reports comparing RALLD or LLLD and open lateral lymph node dissection (OLLD), but few reports comparing RALLD and LLND to each other. METHODS: From November 2014 to August 2020, we compared the short-term outcomes in 40 patients who underwent RALLD and 55 patients who underwent LLLD. RESULTS: The total operative time was significantly longer in the RALLD group than in the LLLD group (p < 0.001). However, lateral dissection time was not significantly different between the groups (p = 0.661). The postoperative hospital time was shorter in the RALLD group than in the LLLD group (p < 0.048). No significant differences were identified in the rates of postoperative bleeding, incisional surgical site infection (SSI), organ/space SSI, urinary disfunction, urinary infection, or small bowel obstruction between the groups. However, anastomotic leakage was significantly lower in the RALLD group than in the LLLD group (p = 0.031). CONCLUSIONS: The short-term outcomes of RALLD indicate it is feasible, and RALLD may be a useful modality for lower rectal cancer.

[Metachronous Gastric Intramural Metastasis following Esophageal Cancer ESD-A Case Study].

We report a case of metachronous gastric intramural metastasis following esophageal cancer endoscopic submucosal dissection( ESD). The patient was an 80s man who was referred to the department of gastroenterology of our hospital for earlystage esophageal cancer by a local physician. ESD was performed for a lesion(Lt, 0-Ⅱa+Ⅱc, cT1N0M0, StageⅠ)located 35- 38 cm from the incisors. Pathologic diagnosis revealed that the lesion was a 2.5×2.0 cm-sized, pSM2, 506 mm, well-differentiated squamous cell carcinoma, ly+, v-, pHM0, pVM0. The patient was indicated for additional treatment, but because the patient requested not to undergo operative treatment, radiation therapy, or chemotherapy, strict follow-upwas performed. Upper endoscopy performed 1 year after ESD revealed the presence of a submucosal tumor(diameter of 5 cm)accompanied by ulceration in the gastric cardia, and biopsy findings led to the diagnosis of squamous cell carcinoma. The patient was referred to our department for operative treatment, and considering the possibility of primary squamous cell carcinoma of the stomach, we performed total gastrectomy(D2 dissection, Roux-en-Y)and cholecystectomy. The pathologic diagnosis was well-differentiated squamous cell carcinoma, ly1, v0, SE, N1. Because esophageal cancer and the tissue type were consistent and the primary locus of the tumor was the submucosal layer, the patient was diagnosed with esophageal cancer with gastric intramural metastasis. We report a rare case of metachronous gastric intramural metastasis of esophageal cancer along with a review of the literature.

[A Case of Advanced Gastric Cancer with Peritoneal Dissemination after Gastrectomy Effectively Treated with Combination Chemotherapy of Ramucirumab and Paclitaxel].

The REGARD and RAINBOW trials revealed the effectiveness of ramucirumab(RAM)for advanced gastric cancer patients who had been previously treated with chemotherapy. In the latest Japanese gastric cancer treatment guidelines, PAM plus paclitaxel(PTX)was positioned as a second-line chemotherapy for advanced gastric cancer. We report a case of advanced gastric cancer with peritoneal dissemination after gastrectomy effectively treated with RAM plus PTX. A 66-year-old woman underwent total gastrectomy with D2 lymph node dissection, splenectomy, and distal pancreatectomy. The pathological diagnosis was poorly differentiated adenocarcinoma, pT4b(pancreas), N3b, P1, CY1, Stage Ⅳ. She was treated with postoperative chemotherapy of S-1 plus cisplatin. However, 5 months after surgery, computed tomography(CT)showed ascites and recurrence of peritoneal dissemination. Cytological examination showed adenocarcinoma cells in the ascites. She was treated with combination chemotherapy of RAM and PTX as second line chemotherapy. After 1 course of this therapy, CT revealed complete disappearance of ascites and significant reduction in the size of the peritoneal dissemination. The patient survived without progression for 8 months after the recurrence was detected.

[Outcomes of Total Mesorectal Excision and Lateral Lymph Node Dissection following Neoadjuvant Chemotherapy for Lower Rectal Cancer with Lateral Lymph Node Metastasis].

INTRODUCTION: Progressive lower rectal cancer with metastasis to the lateral lymph nodes has poor prognosis, requiring systemic chemotherapy. In addition, because laparoscopic lateral lymph node dissection(LLND)in positive cases of metastasis to the lateral lymph nodes is difficult, it has not been commonly used. Here, we report the treatment results of neoadjuvant chemotherapy(NAC)and subsequent laparoscopic total mesorectal excision(TME)plus LLND in cases of lower rectal cancer with metastasis to the lateral lymph nodes. SUBJECTS AND METHODS: The subjects were 4 patients with metastasis to the lateral lymph nodes who underwent LLND after NAC. The surgical outcomes were investigated retrospectively. RESULTS: The mean surgical time was 398 minutes, and the mean bleeding amount was 150 g. In total, 33.5 lymph nodes were dissected, including 15.3 lateral lymph nodes. There was no switch to laparotomy, and no postoperative complications of Grade Ⅲ or higher according to the Clavien-Dindo classification were observed. CONCLUSION: Laparoscopic TME plus LLND after NAC is considered safe and useful as radical surgery for positive cases of metastasis to the lymph nodes.