Objective: To retrospectively review the treatment of patients with colonic diverticular bleeding in our institution, and to evaluate clinical characteristics of patients who underwent surgical treatment.

Methods: A total of 194 patients with colonic diverticular bleeding from January 2010 to April 2020 were enrolled in this study.

Results: Seven (4%) patients underwent surgical treatment. Of these, five had endoscopic treatment followed by surgery, and two had endoscopic and interventional radiology treatment followed by surgery. All patients required blood transfusions to treat hemodynamic shock. Bleeding was in the ascending colon and right hemicolectomy was performed in all patients. One female developed re-bleeding post-operatively three times every three years, and was treated non-operatively. She had multiple diverticula in both the right and left colons, and was taking anticoagulants.

Conclusion: Patients with colonic diverticular bleeding were treated according to the treatment guidelines. Although some patients were in poor condition, their post-operative course was uneventful. While subtotal colectomy is recommended for patients whose bleeding source is unknown in the guidelines, treatment decisions including the range of excision must be made individually depending on the patient's condition (age, activities and comorbidities).

Objective: This study aimed to validate surgical outcomes of robot-assisted rectal surgery for highly difficult cases.

Methods: Highly difficult cases who underwent robot-assisted or laparoscopic rectal surgery between June 2019 and October 2020 were included in this retrospective study. Surgical outcomes including patient characteristics, perioperative outcomes and pathological findings were compared between the robotic and laparoscopic groups. The highly difficult cases were defined as all low rectal cancer or middle rectal cancer with any of the following characteristics: male gender, BMI ≥ 25 kg/m² and tumor size ≥ 5 cm.

Results: A total of 50 patients were enrolled: 24 cases in the robotic group and 26 cases in the laparoscopic group. In the robotic group, blood loss was less (p = 0.007) and postoperative stay was shorter (p = 0.024). There were no statistically significant differences in operating time, conversion rate, postoperative complications or pathological findings between the two groups.

Conclusion: These results suggest that robot-assisted rectal surgery for highly difficult cases has several benefits in terms of surgical outcomes.

A 36-year-old man was found to have a submucosal tumor 15 mm in size in the lower rectum by colonoscopy performed for blood in stool, and was diagnosed as NET G1 by biopsy. Abdominal enhanced CT revealed swelling of the left closed lymph node, but it was calcified by CT, and SUVmax was less than 2 on PET-CT, and diffusion restriction was not observed on MRI. So, we performed robot-assisted abdominoperineal rectal resection (D3LD0). The pathological diagnosis was NET G2, pStage ⅢB, and he was treated by adjuvant chemotherapy with capecitabine. Seven months after surgery, CT revealed an increase in the left closed lymph node. Somatostatin receptor scintigraphy revealed abnormal accumulation in the left closed lymph node, and it was diagnosed as metastasis and was resected. The pathological diagnosis was NET metastasis. Twelve cases of lateral lymph node metastasis of NET have been reported, all of which were diagnosed by CT, PET and MRI. We report a case in which somatostatin receptor scintigraphy was useful for diagnosing metastasis.

The case was a 62-year-old man with the chief complaint of abdominal pain. Blood biochemical examination revealed anemia and an inflammatory reaction, and abdominal findings revealed a mass in the right abdomen. Abdominal CT showed a huge 14 cm-sized mesenteric hematoma in the lower right abdomen, and urgent endovascular treatment was performed to stop bleeding due to suspicion of ruptured aneurysm in the mesentery. After hemostasis, fasting and antibacterial drugs improved the inflammatory findings, but when oral intake was started, abdominal pain and fever reappeared and the inflammatory response increased again. Abdominal CT showed hematoma infection, so surgery was performed. On laparotomy, the hematoma was blackish and had a foul odor, and the patient was diagnosed with hematoma infection. Although the hematoma was removed as much as possible, right hemicolectomy was performed to control infection. The culture result was Porphyromonas gingivalis, which is a common causative agent of periodontal disease. Abdominal visceral aneurysms, especially ileocolic aneurysms, are rare, and there are only eight cases reported in the past. Although IVR is considered to be a useful treatment for aneurysm rupture in the literature, surgery is required once infection occurs.

Fish bones account for a large proportion of foreign bodies in the gastrointestinal tract in Japan, and surgical intervention is often required in case of gastrointestinal perforation. Here we report a case of sigmoid colon perforation by a fish bone. The case was an 86-year-old female. She was admitted to our hospital with a chief complaint of abdominal pain, diarrhea and vomiting. CT examination revealed a linear foreign body with high-density signal at the sigmoid colon, and we diagnosed sigmoid colon perforation caused by it. Intraoperative findings revealed perforation of the sigmoid colon and abscess, so we performed drainage of the abscess cavity and ileostomy in addition to excision and anastomosis of the perforation. There are 38 reports of colon perforation due to fish bones in Japan, including the present case, which are more common in males, and the perforation sites tend to be in the transverse colon and sigmoid colon. About 90% of cases in which abscess or ascites was suspected by preoperative CT examination required surgical treatment. Artificial anus creation tends to be performed in elderly patients, patients with panperitonitis before surgery, and patients with ascites or abscess on preoperative CT examination or intraoperative findings.

We report two cases of filiform polyposis associated with ulcerative colitis that underwent surgery.

Case 1. A 25-year-old man was undergoing treatment for ulcerative colitis for one year. Anemia and malnutrition persisted, and shortness of breath during physical activity was gradually observed. Therefore, he was admitted to our hospital urgently. Colonoscopy revealed extensive inflammatory polyposis from the cecum to the transverse colon and sigmoid colon. Due to impaired passage and no improvement by medical treatment, a total colectomy was performed.

Case 2. A 54-year-old woman had repeated relapses and remissions during 13 years of treatment for ulcerative colitis. She was admitted to our hospital with abdominal pain, diarrhea, and bloody stools. Colonoscopy revealed intestinal stenosis due to extensive inflammatory polyposis from the cecum to the transverse colon. Since medical treatment did not result in improvement, and complications of dysplasia and adenocarcinoma could not be ruled out, subtotal colectomy was performed. Pathology revealed fibrovascular cores in both cases, and the diagnosis was filiform polyposis.

The patient was a 19-year-old male. He had inserted a pencil transanally at home, and it became difficult to remove, but he did not have any symptoms. The following day, however, he had lower abdominal pain and bloody stool, so he went to his local doctor. Abdominal X-ray and CT showed a rod-shaped structure in the sigmoid colon and upper rectum. Manual removal through the anus was difficult, so the structure was removed endoscopically. The patient was discharged from the hospital on the fourth postoperative day without any abdominal symptom exacerbation.

Secondary perineal hernia after rectal amputation is a rare complication. We herein report the case of an obese patient with secondary perineal hernia after laparoscopic rectal amputation for rectal cancer, because it was predicted that a large load would be applied to the perineum during work as a farmer, in which fixation was devised and reliable repair was performed, with a review of the literature. The case was a 63-year-old man, height 170 cm, weight 91 kg, BMI 31.49. Laparoscopic repair was performed 37 days after the first surgery. An oval mesh with an anti-adhesive agent was formed into a bowl shape and placed on the pelvic floor. Mesh tape was sewn onto the front two points and the rear two points of the mesh, and the mesh tape was sutured and fixed to the Cooper's ligaments and promontory of sacrum on both sides so that it could withstand the weight sufficiently. No recurrence was observed for 15 months after the operation. This procedure is considered to be effective to avoid postoperative recurrence in cases where a large load is applied to the pelvic floor.

A 70-year-old man was admitted to another hospital for left hydronephrosis, but his back pain worsened and he was referred to our hospital. As a result of further examination, a diagnosis of sigmoid colon cancer, metastatic liver tumor (lateral segment) and primary left ureteral tumor was made. Since stenosis of sigmoid colon cancer was imminent, hepatectomy was scheduled in the second phase. First, retroperitoneal left nephrectomy and laparoscopic high anterior resection (D3) were performed. The postoperative course was uneventful and he was discharged on the 13th postoperative day. The postoperative pathology revealed that the ureteral cancer was not a primary tumor but a metastatic tumor from colon cancer. Postoperative CT examination showed an enlarged lymph node near the resected left kidney, and metastasis or residual tumor could not be ruled out. Therefore, PET-CT was performed, and showed sacral bone metastasis at the S4-5 level. Since metastatic ureteral tumors have a poor prognosis with a high rate of distant metastasis, he was introduced to our Cancer Treatment Center for the purpose of multidisciplinary treatment and is currently being treated.

Colonoscopy revealed cancer in the sigmoid colon of a 53-year-old woman, and the biopsy result was moderately differentiated adenocarcinoma. Abdominal computed tomography and magnetic resonance imaging revealed swelling of the lymph nodes and bilateral ovaries and irregular nodules in the right inguinal region. A tumor of the sigmoid colon cancer with abdominal wall metastasis of the inguinal region and ovarian metastasis was diagnosed. Sigmoidectomy was conducted and followed by D3 lymph node dissection, bilateral ovariectomy, and right inguinal tumor resection. During the operation, a mass was found in the inguinal canal, and it was deemed to be a round ligament tumor. Pathological examination revealed that both the ovarian and uterine cord tumors were metastases of the sigmoid colon cancer. Following postoperative adjuvant chemotherapy, multiple recurrences were observed in the left inguinal canal and pelvis 19 months after the operation, and the patient is currently undergoing chemotherapy. Round ligament metastasis of colorectal cancer is rare. A lymphatic route from around the uterus to the inguinal canal along the round ligament has been reported, which might have caused metastasis in this case. In colorectal cancer with ovarian metastasis, it is necessary to consider the possibility of inguinal round ligament metastasis.