Data registries lack a definitive classification system that distinguishes different locations of colon cancer from one another.To establish an international consensus on the definition of primary colon cancer segment locations.Between December 2022 and June 2023, the Delphi survey study was conducted to seek opinions from relevant international experts and eventually develop a consensus definition of each colon cancer segment.Three-round online-based Delphi survey study.The online survey included 17 questions. In the first 2 rounds, participating experts were asked to rank each statement on a scale of 1 (least relevant) to 9 (most relevant). Consensus statements and definitions were revised according to the results for statements obtaining a consensus score of 7 to 9. During the third round and online meeting, definitions and statements that reached a moderate or high consensus (above 4 for more than 70% of participants) were included.The primary goal of our project was focused on precisely localizing the specific segment affected by primary colon cancer rather than identifying surgical treatment or type of resection needed for a particular segment.The first round included 331 experts; 301 (91%) completed the second round and 295 (98%) completed the final round. Experts strongly supported the use of a "10-cm rule" to describe colon cancer sites at the flexures and anatomical landmarks for other segments. Regarding the definition of rectosigmoid cancer, experts from United States and Europe reached a high consensus that the term rectosigmoid as a colon cancer location must be abolished in contrast to experts from Asia. The description of overlapping segments of cancers achieved a consensus of 64%.Subjective decisions are based on individual expert clinical experience.This Delphi survey, the first internationally conducted consensus study, achieved a remarkable level of consensus among a panel of global experts. Ambiguity still exists regarding overlapping lesions. See Video Abstract.ANTECEDENTES:Las bases de datos carecen de un sistema de clasificación definitivo que distinga las diferentes localizaciones del cáncer de colon.OBJETIVO:Establecer un consenso internacional sobre la definición de las localizaciones de los segmentos del cáncer de colon priamrio.DISEÑO:Entre diciembre de 2022 y junio de 2023, se realizó un estudio Delphi para recabar la opinión de expertos internacionales relevantes y, finalmente, desarrollar una definición consensuada de cada segmento del cáncer de colon.ESCENARIO:Estudio Delphi en línea de 3 rondas.INTERVENCIONES:La encuesta en línea incluyó 17 preguntas. En las dos primeras rondas, se pidió a los expertos participantes que calificaran cada afirmación en una escala del 1 al 9 (9 es la más relevante). Las afirmaciones y definiciones de consenso se revisaron según los resultados, obteniendo una puntuación de consenso de 7 a 9. Durante la tercera ronda y la reunión en línea, se incluyeron las definiciones y afirmaciones que alcanzaron un consenso moderado o alto (superior a 4 en más del 70 % de los participantes).MEDIDA PRINCIPALES DE RESULTADOS:El objetivo principal de nuestro proyecto se centró en localizar con precisión el segmento específico afectado por el cáncer de colon primario, en lugar de identificar el tratamiento quirúrgico o el tipo de resección necesario para un segmento en particular.RESULTADOS:La primera ronda incluyó a 331 expertos, 301 (91%) completaron la segunda ronda y 295 (98%) completaron la ronda final. Los expertos apoyaron firmemente el uso de una "regla de 10 cm" para describir las localizaciones del cáncer de colon en las flexuras y puntos de referencia anatómicos para otros segmentos. En cuanto a la definición de cáncer rectosigmoideo, expertos de América y Europa alcanzaron un alto consenso en la necesidad de abolir el término "rectosigmoide" como localización del cáncer de colon, a diferencia de los expertos de Asia. La descripción de los cánceres en segmentos que se superponen a alcanzó un consenso del 64%.LIMITACIONES:Las decisiones subjetivas se basan en la experiencia clínica individual de cada experto.CONCLUSIONES:Esta encuesta Delphi, el primer estudio de consenso realizado a nivel internacional, alcanzó un notable nivel de consenso entre un panel de expertos globales. Todavía existe ambigüedad en cuanto a las lesiones superpuestas. (Traducción-Dr. Jorge Silva Velazco ).Copyright © The ASCRS 2025.

Colorectal cancer (CRC) is a common malignant tumor of the digestive system, characterized by a high incidence and mortality rate. This study aimed to investigate the epidemiological characteristics of CRC between 1990 and 2021.

Five cases are described where minute foci of adenocarcinoma have been demonstrated in the mesorectum several centimetres distal to the apparent lower edge of a rectal cancer. In 2 of these there was no other evidence of lymphatic spread of the tumour. In orthodox anterior resection much of this tissue remains in the pelvis, and it is suggested that these foci might lead to suture-line or pelvic recurrence. Total excision of the mesorectum has, therefore, been carried out as a part of over 100 consecutive anterior resections. Fifty of these, which were classified as ‘curative’ or ‘conceivably curative’ operations, have now been followed for over 2 years with no pelvic or staple-line recurrence.

In humans, the incidence of congenital defects of the intraembryonic celom and its associated structures has increased over recent decades. Surgical treatment of abdominal and diaphragmatic malformations resulting in congenital hernia requires deep knowledge of ventral body closure and the separation of the primary body cavities during embryogenesis. The correct development of both structures requires the coordinated and fine-tuned synergy of different anlagen, including a set of molecules governing those processes. They have mainly been investigated in a range of vertebrate species (e.g., mouse, birds, and fish), but studies of embryogenesis in humans are rather rare because samples are seldom available. Therefore, we have to deal with a large body of conflicting data concerning the formation of the abdominal wall and the etiology of diaphragmatic defects. This review summarizes the current state of knowledge and focuses on the histological and molecular events leading to the establishment of the abdominal and thoracic cavities in several vertebrate species. In chronological order, we start with the onset of gastrulation, continue with the establishment of the three-dimensional body shape, and end with the partition of body cavities. We also discuss well-known human etiologies.

Recent advances in mesenteric anatomy have clarified the shape of the mesentery in adulthood. A key finding is the recognition of mesenteric continuity, which extends from the oesophagogastric junction to the mesorectal level. All abdominal digestive organs develop within, or on, the mesentery and in adulthood remain directly connected to the mesentery. Identification of mesenteric continuity has enabled division of the abdomen into two separate compartments. These are the mesenteric domain (upon which the abdominal digestive system is centered) and the non-mesenteric domain, which comprises the urogenital system, musculoskeletal frame, and great vessels. Given this anatomical endpoint differs significantly from conventional descriptions, a reappraisal of mesenteric developmental anatomy was recently performed. The following narrative review summarizes recent advances in abdominal embryology and mesenteric morphogenesis. It also examines the developmental basis for compartmentalizing the abdomen into two separate domains along mesenteric lines.

Laparoscopic complete mesocoloic excision (CME) with central vascular ligation for splenic flexure cancer is technically challenging because of its anatomical complexity. Although embryological and anatomical consideration should be helpful to perform CME in colorectal cancer surgery, such studies on the splenic flexure are lacking.The splenic flexure is located embryologically between the terminal portion of the midgut and the beginning of the hindgut, and is supplied by the superior mesenteric and inferior mesenteric arteries. The mesentery of the transverse and descending colon originally is a continuous sheet, although they rotate and partially fuse to each other during development. Our surgical strategy was excision of the transverse and descending mesocolon with ligation of the left colic artery and left branch of the middle colic artery, and extraction of the specimen in an intact package wrapped by the embryological planes.We performed laparoscopic surgery according to our surgical strategy in 17 patients with splenic flexure colon cancer. There were no conversions to open surgery or serious intraoperative complications. Two patients had pathological stage (pStage) I, 5 pStage II, 9 pStage III, and 1 pStage IV disease. No patient had recurrence except for 1 with pStage IV cancer, with a median follow-up of 16 months.Our laparoscopic CME technique is feasible for treatment of splenic flexure cancer. Knowledge of anatomy based on embryology is essential to perform this surgery.

Mesothelial, neurovascular, lymphatic, adipose and mesenchymal tissues make up the mesentery. These tissues are pathobiologically important for numerous reasons. Collectively, they form a continuous, discrete and substantive organ. Additionally, they maintain abdominal digestive organs in position and in continuity with other systems. Furthermore, as they occupy a central position, they mediate transmission of signals between the abdominal digestive system and the remainder of the body. Despite this physiologic centrality, mesenteric tissue development has received little investigatory focus. However, recent advances in our understanding of anatomy demonstrate continuity between all mesenteric tissues, thereby linking previously unrelated studies. In this review, we examine the development of mesenteric tissue in normality and in the setting of congenital abnormalities.Copyright © 2018 Elsevier Ltd. All rights reserved.

Surgery for colorectal cancer located in the splenic flexure is difficult to perform because of the complex anatomy. Recently, in addition to the middle colic artery and left colic artery (LCA), the accessory middle colic artery (AMCA) has been recognized as a feeding artery for the left‐sided colon. This study aimed to evaluate the vascular anatomy of the splenic flexure focusing on the AMCA in a large number of patients.

The aim of this study was to compare the short- and long-term outcomes of splenic flexure colectomy (SFC), left hemicolectomy (LHC) and extended left hemicolectomy (ELHC) for splenic flexure colon cancer.