The anorectum is a region with a very complex structure, and surgery for benign or malignant disease of the anorectum is impossible without accurate anatomical knowledge. The conjoined longitudinal muscle consists of smooth muscle from the longitudinal muscle of the rectum and the striate muscle from the levator ani and helps maintain continence; the rectourethralis muscle is connected directly to the conjoined longitudinal muscle at the top of the external anal sphincter. Preserving the rectourethralis muscle without damage to the carvernous nerve or veins passing through it when the abdominoperineal resection is implemented is important. The mesorectal fascia is a multi-layered membrane that surrounds the mesorectum. Because the autonomic nerves also pass between the mesorectal fascia and the parietal fascia, a sharp pelvic dissection must be made along the anatomic fascial plane. With the development of pelvic structure anatomy, we can understand better how we can remove the tumor and the surrounding metastatic lymph nodes without damaging the neural structure. However, because the anorectal anatomy is not yet fully understood, we hope that additional studies of anatomy will enable anorectal surgery to be performed based on complete anatomical knowledge.

BackgroundAlthough perioperative chemotherapy has been the standard treatment for colorectal cancer with resectable liver metastases (CRLM), studies that have compared neoadjuvant chemotherapy (NAC) and upfront surgery, especially in the setting of synchronous metastases are rare.MethodsWe compared perioperative outcomes, overall survival (OS) and overall survival after recurrence (rOS) in a retrospective study of 281 total and 104 propensity score‐matched (PSM) patients who underwent curative resection, with or without NAC, for synchronous CRLM, from 2006 to 2017. A Cox regression model was developed for OS.ResultsAfter PSM, 52 NAC and 52 upfront surgery patients with similar baseline characteristics were compared. Postoperative morbidity, mortality, and 5‐year OS rate (NAC: 78.9%, surgery: 64.0%; p = 0.102) were similar between groups; however, the NAC group had better rOS (NAC: 67.3%, surgery: 31.5%; p = 0.049). Initial cancer stage (T4, N1–2), poorly differentiated histology, and >1 hepatic metastases were independent predictors of worse OS. Based on these factors, patients were divided into low‐risk (≤1 risk factor, n = 115) and high‐risk (≥2 risk factors, n = 166) groups. For high‐risk patients, NAC yielded better OS than upfront surgery (NAC: 74.5%, surgery: 53.2%; p = 0.024).ConclusionsAlthough NAC and upfront surgery‐treated patients had similar perioperative outcomes and OS, better postrecurrence survival was shown in patients with NAC. In addition, NAC may benefit patients with worse prognoses; therefore, physicians should consider patient disease risk before initiating treatment to identify patients who are most likely to benefit from chemotherapy.

Purpose: Desmoid tumors are locally aggressive tumors with no known potential for metastasis. They tend to recur even after complete excision. Sometimes it is not easy to differentiate between intra-abdominal desmoid and tumor recurrence, especially after gastrointestinal (GI) tumor resection. The current study aims to review the characteristics, management, and outcomes of patients with intra-abdominal desmoid tumor post GI resection. Methods: During the period between 2007 and 2018, after a retrospective review of patients' clinical data, 10 patients were finally included. Medical records were screened for demographic, clinical, pathological data, management strategy, postoperative morbidity, mortality, recurrence rate and follow-up. Results: The study comprised 10 patients (8 males). The median age was 53.5 years (range, 35-68 years). Two patients diagnosed as familial adenomatous polyposis (FAP). All the patients underwent previous GI resection: three (30%) for colon cancer, three (30%) gastrectomy, two (20%) total proctocolectomy with ileal pouch-anal anastomosis (TPC+IPAA) for FAP, one (10%) low anterior resection (three rectal cancers) and one (10%) distal pancreatectomy. The tumor was found to be in bowel mesentery in eight cases (80%). The median tumor size was 5.3 cm (range, 2.6-19.0 cm). Six patients (60%) underwent open resection, while four patients (40%) underwent laparoscopic surgery. Complications occurred in five cases (50%) and ranged from Clavien-Dindo (II-III). The median follow-up period was 16.5 months (1.5-136.0 months) with recurrence in one case (10%). Pathology came out to be desmoid tumor fibromatosis in all cases. Conclusion: When a mass develops after surgical resection for abdominal GI malignancy and tends to be large in size, located in the bowel mesentery and away from previous primary tumor site, most probably it is desmoid rather than tumor recurrence.