[Re-thinking of "pelvirectal space"].

Before the "mesorectal" theory was proposed, the traditional anatomy believed that the "pelvirectal space" belonged to the anal canal and perirectal space, which was independent of the rectal structure, located on both sides of the rectum, above the levator ani, and below the peritoneal reflexion, and was composed of a large amount of fatty tissue filling. With the development of the theory of membrane anatomy and the clarification of the concept of "rectal mesentery", combined with the author's clinical experience, we found that the above-mentioned fat is actually the fat within the mesorectum, as well as the fat tissue of lateral lymph nodes (LLN) such as the internal iliac lymph nodes (No.263) and obturator lymph nodes (No.283) on both sides of the rectal mesentery, rather than the so-called fat tissue within the interstitial space. Therefore, the author believes that the pelvirectal space does not exist. In the anatomical location equivalent to the pelvic rectal space, there is the "superior levator ani space" based on the membrane anatomy theory. From the pelvirectal space to the superior levator anal space, it reflects our further understanding of the anatomy of the rectal mesentery.

[Chinese expert consensus on definition and terminology of colon and rectum: mesentery, fascia, and space (2023 edition)].

Anatomy is the foundation of surgery. However, traditional anatomical concepts based on autopsy are no longer sufficient to guide the development of modern surgery. With the advancement of histology and embryology and application of high-resolution laparoscopic technology, surgical anatomy has gradually developed. Meanwhile, some important concepts and terms used to guide surgery have emerged, including: mesentery, fascia, and space. The confusing, controversial, and even inaccurate definitions and anatomical terms related to colorectal surgery seriously affect academic communication and the training of young surgeons. Therefore, the Chinese Society of Colorectal Surgeons, the Chinese Society of Colorectal Surgery, National Health Commission Capacity Building and Continuing Education Center, and China Sexology Association of Colorectal Functional Surgery organized colorectal surgeons to make consensus on the definition and terminology of mesentery, fascia, and space related to colon and rectum, to promote surgeons' understanding of modern anatomy related to colorectal surgery and promote academic communication.

Chinese expert consensus on definition and terminology of colon and rectum: mesentery, fascia, and space (2023 edition) / 中华胃肠外科杂志

Anatomy is the foundation of surgery. However, traditional anatomical concepts based on autopsy are no longer sufficient to guide the development of modern surgery. With the advancement of histology and embryology and application of high-resolution laparoscopic technology, surgical anatomy has gradually developed. Meanwhile, some important concepts and terms used to guide surgery have emerged, including: mesentery, fascia, and space. The confusing, controversial, and even inaccurate definitions and anatomical terms related to colorectal surgery seriously affect academic communication and the training of young surgeons. Therefore, the Chinese Society of Colorectal Surgeons, the Chinese Society of Colorectal Surgery, National Health Commission Capacity Building and Continuing Education Center, and China Sexology Association of Colorectal Functional Surgery organized colorectal surgeons to make consensus on the definition and terminology of mesentery, fascia, and space related to colon and rectum, to promote surgeons' understanding of modern anatomy related to colorectal surgery and promote academic communication.

[Study on mesentary margin in supply vessel-oriented radical resection of colorectal cancer].

The concept of radical surgery has experienced from vascular anatomy guidance, lymph node dissection guidance to en-bloc resection guidance. At present, the mesentery guided surgery has developed to a new level of understanding. There are many classical theories on the understanding of the mesentery, from "the mesentery is a wrapped composite structure" to "the mesentery is an organ" and then to "the generalized mesentery theory", but they do not clearly put forward the boundary mark of the mesentery. On the basis of various membrane anatomy theories at home and abroad, we summarized and defined three boundaries of mesenteric excision in radical resection of colorectal cancer. The lateral boundary of the mesentery is the intestinal resection boundary and its mesentery oriented by supplyvessel, the bottom boundary is the mesentery bed, and the central boundary is the degree of lymph node radical resection. Through the detailed description of the mesentery excision, it is helpful to accurately define the mesenteric margin in different stages of radical resection of tumors.

Update on the mesentery: structure, function, and role in disease.

Over the past 5 years, systematic investigation of the mesenteric organ has expanded and shown that the mesentery is the organ in and on which all abdominal digestive organs develop and remain connected to. In turn, this observation has clarified the anatomical foundation of the abdomen and the fundamental order at that level. Findings related to the shape and development of the mesentery have illuminated its function, advancing our understanding of the pathobiology, diagnosis, and treatment of several abdominal and systemic diseases. Inclusion of the mesentery in surgical resections alters the course of benign and malignant diseases. Mesenteric-based scoring systems can enhance the radiological interpretation of abdominal disease. Emerging findings reconcile observations across scientific and clinical fields and have been assimilated into reference curricula and practice guidelines. This Review summarises the developmental, anatomical, and clinical advances made since the mesentery was redesignated as an organ in 2016.

The development and structure of the mesentery.

The position of abdominal organs, and mechanisms by which these are centrally connected, are currently described in peritoneal terms. As part of the peritoneal model of abdominal anatomy, there are multiple mesenteries. Recent findings point to an alternative model in which digestive organs are connected to a single mesentery. Given that direct evidence of this is currently lacking, we investigated the development and shape of the entire mesentery. Here we confirm that, within the abdomen, there is one mesentery in which all abdominal digestive organs develop and remain connected to. We show that all abdominopelvic organs are organised into two, discrete anatomical domains, the mesenteric and non-mesenteric domain. A similar organisation occurs across a range of animal species. The findings clarify the anatomical foundation of the abdomen; at the foundation level, the abdomen comprises a visceral (i.e. mesenteric) and somatic (i.e. musculoskeletal) frame. The organisation at that level is a fundamental order that explains the positional anatomy of all abdominopelvic organs, vasculature and peritoneum. Collectively, the findings provide a novel start point from which to systemically characterise the abdomen and its contents.

Surgical Anatomy of the Rectovaginal Space: Does a Standalone Rectovaginal Septum or Denonvilliers Fascia Exist in Women?

BACKGROUND: Below the anterior peritoneal reflection, the anterior rectal wall and mesorectum are separated from the posterior vaginal wall by a virtual rectovaginal space. In this space, the description of a specific and independent rectovaginal septum as a female counterpart of Denonvilliers fascia has been the subject of debate over the years. OBJECTIVE: The aim of this study is to perform an accurate anatomical study of the rectovaginal area in a cadaveric simulation model of total mesorectal excision to evaluate the possible structures and the dissection planes contained within the rectovaginal space. DESIGN AND SETTING: This is a cadaveric study performed at the University of Valencia. PATIENTS: The pelvises of 25 formalin-preserved female cadavers were dissected. All the included specimens were sectioned in a midsagittal plane, at the level of the middle axis of the anal canal. MAIN OUTCOME MEASURES: Careful and detailed dissection was performed to visualize the anatomical structures and potential dissection planes during anterior mesorectal dissection in cadavers. Histological sections were made of the posterior vaginal wall. RESULTS: The rectovaginal space contains loose areolar tissue that allows an easy dissection plane distally. A distinct and independent rectovaginal fascia or septum is not present. The existence of 3 layers fused together in the posterior vaginal wall can be identified more or less precisely because of their different coloration. The histological study confirms this macroscopic arrangement of the posterior vaginal wall in 3 layers: the mucosa, the muscular, and the adventitia. An independent rectovaginal septum can be generated only with a splitting of the adventitia. LIMITATIONS: The cadaveric pelvic specimens of the oldest donors might have had age-related degeneration. CONCLUSIONS: The present anatomical study has shown only a plane of loose areolar tissue between the rectal and vaginal wall. We can conclude that there is no independent fascia or septum in the rectovaginal space. See Video Abstract at http://links.lww.com/DCR/B456. ANATOMÍA QUIRÚRGICA DEL ESPACIO RECTOVAGINAL: ¿EXISTE UN TABIQUE RECTOVAGINAL INDEPENDIENTE O UNA FASCIA DE DENONVILLIERS EN LAS MUJERES: Debajo del reflejo peritoneal anterior, la pared rectal anterior y el mesorrecto están separados de la pared vaginal posterior por un espacio rectovaginal virtual. En este espacio, la descripción de un tabique rectovaginal independiente específico como contraparte femenina de la fascia de Denonvilliers ha sido objeto de debate a lo largo de los años.Realizar un estudio anatómico preciso del área rectovaginal en un modelo de simulación cadavérica de escisión mesorrectal total, con el fin de evaluar las posibles estructuras y los planos de disección contenidos en el espacio rectovaginal.estudio cadavérico realizado en la Universidad de Valencia.Se disecaron las pelvis de 25 cadáveres femeninos conservados en formalina. Todas las muestras incluidas fueron seccionadas en un plano medio sagital, a la altura del eje medio del canal anal.Se llevó a cabo una disección cuidadosa y detallada para visualizar las estructuras anatómicas y los posibles planos de disección durante la disección mesorrectal anterior en cadáveres. Se realizaron cortes histológicos de la pared vaginal posterior.El espacio rectovaginal contiene tejido areolar laxo que permite un plano de disección fácil distalmente. No hay fascia o tabique rectovaginal distinto e independiente. La existencia de tres capas fusionadas en la pared vaginal posterior puede identificarse con mayor o menor precisión debido a su diferente coloración. El estudio histológico confirma esta disposición macroscópica de la pared vaginal posterior en tres capas: la mucosa, la muscular y la adventicia. Un tabique rectovaginal independiente solo se puede generar con una división de la adventicia.Las muestras pélvicas de cadáveres de los donantes más antiguos pueden haber tenido degeneración relacionada con la edad.El estudio anatómico actual solo ha mostrado un plano de tejido areolar laxo entre la pared rectal y vaginal. Podemos concluir que no hay fascia o tabique independiente en el espacio rectovaginal. Consulte Video Resumen en http://links.lww.com/DCR/B456. (Traducción-Dr. Adrian Ortega).

Morphological speculation of the MHPD and related clinical projections.

OBJECTIVE: The concept of mesopancreas has been brought into focus nowadays. Studies on membrane morphology of pancreas are clinically significant in determining an ideal surgical route for a "holy plane". In this paper, we aimed to observe the structure of the peripancreatic membranes and its interactions with adjacent tissues; tentatively put forward the proposition of mesohepatopancreaticoduodenum (MHPD) and explore in depth in surgical local resection. METHODS: 33 cadavers were examined in the experiment, including 30 for gross anatomy and 3 for histological observation after transection. The histological characteristics of the membrane covering the pancreas were proved by Masson and Bielschowsky silver staining and further explored in clinical application and testified in a surgical scenario. All above were carried out through traditional procedures. RESULTS: The anterior surface membrane of the pancreas was intact and the posterior portion expanding to the pancreaticoduodenum enclosed the surface of the duodenum and the pancreatic head, which could be easily isolated from the posterior abdominal wall. The posterior surface membrane around the body and tail wrapped the pancreatic parenchyma, which created a soft-tissue window for the posterior abdominal wall. Then, dense connective tissue adhesions were detected between the celiac artery and the superior mesenteric artery. CONCLUSIONS: The embryonic origin of the mesopancreas and the surgical procedures were reviewed and inspected based on the proposition of MHPD and above results. We hope that this study could stir up our interest in the advancement of imaging diagnoses and minimally invasive surgical treatment of pancreas.

[Intraoperative anatomical observation of mesentery morphology of colonic splenic flexure].

Objective: At present, surgeons do not know enough about the mesenteric morphology of the colonic splenic flexure, resulting in many problems in the complete mesenteric resection of cancer around the splenic flexure. In this study, the morphology of the mesentery during the mobilization of the colonic splenic flexure was continuously observed in vivo, and from the embryological point of view, the unique mesenteric morphology of the colonic splenic flexure was reconstructed in three dimensions to help surgeons further understand the mesangial structure of the region. Methods: A total of 9 patients with left colon cancer who underwent laparoscopic radical resection with splenic flexure mobilization by the same group of surgeons in Union Hospital of Fujian Medical University from January 2018 to June 2019 were enrolled. The splenic flexure was mobilized using a "three-way approach" strategy based on a middle-lateral approach. During the process of splenic flexure mobilization, the morphology of the transverse mesocolon and descending mesocolon were observed and reconstructed from the embryological point of view. The lower margin of the pancreas was set as the axis, and 4 pictures for each patient (section 1-section 4) were taken during middle-lateral mobilization. Results: The median operation time of the splenic flexure mobilization procedure was 31 (12-55) minutes, and the median bleeding volume was 5 (2-30) ml. One patient suffered from lower splenic vessel injury during the operation and the bleeding was stopped successfully after hemostasis with an ultrasound scalpel. The transverse mesocolon root was observed in all 9 (100%) patients, locating under pancreas, whose inner side was more obvious and tough, and the structure gradually disappeared in the tail of the pancreatic body, replaced by smooth inter-transitional mesocolon and dorsal lobes of the descending colon. The mesenteric morphology of the splenic flexure was reconstructed by intraoperative observation. The transverse mesocolon was continuous with a fan-shaped descending mesocolon. During the embryonic stage, the medial part (section 1-section 2) of the transverse mesocolon and the descending mesocolon were pulled and folded by the superior mesenteric artery (SMA). Then, the transverse mesocolon root was formed by compression of the pancreas on the folding area of the transverse mesocolon and the descending mesocolon. The lateral side of the transverse mesocolon root (section 3-section 4) was distant from the mechanical traction of the SMA, and the corresponding folding area was not compressed by the tail of the pancreas. The posterior mesangial lobe of the transverse mesocolon and the descending mesocolon were continuous with each other, forming a smooth lobe. This smooth lobe laid flat on the corresponding membrane bed composed of the tail of pancreas, Gerota's fascia and inferior pole of the spleen. Conclusions: From an embryological point of view, this study reconstructs the mesenteric morphology of the splenic flexure and proposes a transverse mesocolon root structure that can be observed consistently intraopertively. Cutting the transverse mesocolon root at the level of Gerota's fascia can ensure the complete resection of the mesentery of the transverse colon.

[Reappraisal of the lateral rectal structure].

Colorectal surgeons have focused on the lateral structure of rectum for a long time and lateral ligament is the common term to depict this structure. A better understanding of lateral rectal structure could be beneficial to performing the total mesorectum excision (TME) procedure and protecting patients' urinary, sexual and defecation function. The main controversies focus on two aspects: (1) Does the lateral ligament exist? (2) What dose it contain? Does the middle rectal artery exist? Up to now, anatomic studies have failed to reach consensus on the lateral rectal structure. However, surgeons do find the lateral rectal ligament during surgery and it may be the pathway for lateral lymph node metastasis in rectal cancer. The lateral rectal structure contains the middle rectal artery, nerve branches, lymphatics and adipose fibrous tissue around them. We summarize our clinical experience and conclude that the middle rectal artery appears in lateral ligament constantly but some of them are too small to be easily observed. Therefore, regarding the perspective of membrane anatomy, embryology and surgery, this structure may be more appropriate to be called the "lateral mesorectum". We propose this new term based on the previous literature and our own experience for the readers' reference.

Variations in Laminar Arrangements of the Mesocolon and Retropancreatic Fascia: a Histological Study Using Human Fetuses Near Term.

OBJECTIVE: The embryonic mesentery of the ascending and descending colons as well as the pancreas disappears due to peritoneal fusion, but there might be no or few photographic demonstrations of the intermediate morphologies during the process. The aims of this study were to characterize the morphological relationship of the interface between the renal fascia and peritoneum. METHODS: Fourteen late-stage fetuses with crown rump lengths (CRLs) of 250-325 mm (gestational age: 30-38 weeks) were histologically examined. RESULTS: The renal fascia, a thick or thin layer consisting of densely-distributed abundant fibers, was consistently separated from the renal capsule by a perirenal space containing fat. The transverse colon carried a typical mesocolon histologically different from the renal fascia. The ascending and descending mesocolons were irregularly divided into multiple laminae and the colic external longitudinal muscle appeared to directly contact the renal fascia. There was a spectrum of variations from multiple laminae to a single thick fascia between the pancreatic body and the left kidney or adrenal. CONCLUSIONS: A fascial development after retroperitoneal fusion of the mesentery showed great individual and site-dependent differences in proportion of 1) a complete fusion with the renal fascia and 2) a multilaminar structure including the remnant peritoneum. These variations masked the likely stage-dependent change.

[Rise and mix of membrane anatomy].

Membrane anatomy is the anatomy of mesentery in broad sense and its beds, which was merged from clinical results of surgical practice, optic observation and traditional theories contradiction or omission. Membrane anatomy is not only a plane, but also a body or bloc which is surrounded by fascia and serous membrane. It is not only fascia, but also a channel or pathway, in which the life event occurred. It is not only mesentery anatomy, but included mesentery beds, on which the mesentery was lied, even buried in. Following the new version of this anatomy map, surgical hazard during operation and postoperative oncological recurrence will be decreased simultaneously. And, following the definition of the mesentery in broad sense, new mesenteries will be discovered under macro surgery, which will optimize surgical operation and get better surgical and oncological results.

[Are various theoretical models of membrane anatomy mutually exclusive or inclusive?]

The theory of membrane anatomy is now widely accepted due to the observation of fine anatomical structure with the help of laparoscopic magnifying effect. From the perspective of systematic anatomy, the mesentery is considered as an integral organ in the theory of mesenteric anatomy. Interfascial anatomy belongs to regional anatomy, which focuses on the guiding significance of fascial space for operation. The theory of membrane anatomy belongs to surgical anatomy or applied anatomy, which emphasizes the anatomy of membrane and mesangial bed, and reveals the existence of 'metastasis V' in the mesentery. It is considered that the essence of membrane anatomy operation is to prevent cancer leakage. Various theories of membrane anatomy seek common ground while reserving differences, complement each other, and upgrade iteratively. They help to explain the structure and function of membrane from different perspectives and they are of great benefit to improve the quality of operations. Thus, they should be treated in an eclectic manner.

[Scientific interpretation of membrane anatomy theory and standardized application of membrane anatomy terms].

There has been an upsurge of the theory of membrane anatomy in China, but it is still in the initial stage of establishing preliminary framework. The concept of fasciae in membrane anatomy actually refers to the fasciae constituting the particular plane or the 'holy plane'. Therefore, the membrane anatomy can't simply be defined as the anatomical relationship among fascia. The application of the membrane anatomy is also not just to pursue the avascular plane in the surgical field. Nowadays, nonstandard anatomical terms and diversification of views impede the development of the theory of the membrane anatomy. Fasciae occur in embryonic stage, undergo a series of changes in rotation and fusion, and lose the original features, which bring difficulties in understanding the anatomy of fasciae. In this paper, we restore the origin and continuity of fasciae related to the colorectal surgery by cadaveric study, surgical observation and literature review. Taking the TME for example, we also discuss the core content about the fasciae and plane related to 'mesenteric envelope' and complete mesorectal excision. From the perspective of the fasciae integrity, we illustrate the definitions of important anatomical structure and standardized the terminology of fasciae. To study the origin and architecture of fasciae in the view of embryology, integrity and continuity will contribute to establish the standard theoretical system of membrane anatomy.

[Application of membrane anatomy in key technologies during gastric cancer surgery: guidance and compromise].

Different from classical surgical anatomy which only pays attention to the morphology and structure of human organs, modern membrane anatomy focuses on not only the relationship between morphology and structure, but also the biological behavior characteristics of tumors. Membrane antomy is a theoretical system with interpretation on both the structural and disease function, so it has been accepted by more and more gastrointestinal surgeons. However, the theoretical system of gastric membrane anatomy is not mature yet. The stomach and its mesentery have undergone complex rotation and fusion in the process of embryonic development, so that surgeons have different understandings of the gastric membrane anatomy. Therefore, it is easy to cause various confusion and misunderstanding, resulting in deviations between the theory of membrane anatomy and the practice of surgery. In the present study, the mesentery of the stomach is divided into different regions, and the embryonic development process is traced back. The application and compromise encountered in the radical gastrectomy of gastric cancer will be expounded according to the membrane anatomy theory combined with the author's experience of operation.

[Mesogastrium theory of D2 lymphadenectomy for advanced gastric cancer: cogitation and skills].

D2 lymphadenectomy combined with complete mesentery excision (CME) for advanced gastric cancer in recent years was a hotspot issue in China, while its safety and effectiveness have been proved. According to the Membrane anatomy of the stomach, both surgical approach and mesogastrium interval is particularly important in Laparoscopic radical gastrectomy. We summarized and shared the following clinical experience for medical colleagues. (1) Lymph nodes of right abdominal aorta-No.7,8,9,12-should be resection as an indivisible whole. This integrity tissue above the portal vein was supposed to the end of the dorsal mesentery of stomach and the continuation of Gerota fascia. (2) No.10 (splenic hilar lymph nodes) lymphadenectomy: The surgical approach enters the Gerota fascia between the left gastric artery(LGA) and the left alongside the splenic artery. When the extent of lymphadenectomy performed to cardia and upper margin of the spleen, then the ultrasonic scalpel should excise the lymph node along the splenic artery to the splenic hilum. (3) Esophagogastric junctional cancer: There is no consensus over the type of resection and the extent of lymphadenectomy that could be a standard of care for this category.While we recommended that paraesophageal lymph node dissection and digestive tract reconstruction should be completed in 3D laparoscopy vision. (4) Infracardiac bursa(ICB): Intentional entry into the ICB provides surgeons with a landmark to identify the location of the pleura, and inferior vena cava. (5)The application of endoscopic aspirator with flushing and electrocautery. The CME concept of gastric cancer emphasizes the membrane anatomy theory rather than the regional lymph node. The precision and homogeneity of the D2 procedure therapy of gastric cancer depend on complete mesentery excision, standard the surgical process, or approach. Only in this way can we find the avascular gaps easily and perfectly cover the extent of lymph node dissection required for the D2 procedure.

[Concept of membrane anatomy in laparoscopic sleeve gastrectomy procedure].

Membrane anatomy refers to the fascia and/or serosa enveloping the organs and their blood vessels and hanging on the posterior wall of the body cavity, which emphasizes the entirety and integrity of the membrane during operation. The concept can also be applied to most surgical operations. This article mainly expounds the application of the concept of membrane anatomy in the process of laparoscopic sleeve gastrectomy, which is embodied in the key steps of separating the greater omentum, mobilizing the fundus, mobilizing the posterior wall of the stomach, cutting the greater curvature of the stomach, reinforcing the staple line of the stomach, and suturing the greater omentum with staple line, in order to make the laparoscopic sleeve gastrectomy more accurate and precise with less bleeding, fewer complications and faster postoperative recovery.

[Thinking of the application of membrane anatomy in gastric cancer surgery after neoadjuvant therapy].

The standard treatment for advanced gastric cancer remains surgery-based comprehensive treatment. The D2 radical surgery has made outstanding contributions to the standarlization of gastric cancer surgery, which has improved patients' prognosis and quality of life. In recent years, neoadjuvant chemotherapy has achieved a certain effect on the treatment of advanced gastric cancer. With the continuous development of the concept of membrane anatomy in gastric cancer surgery, new surgical challenges have also been raised. For patients after neoadjuvant therapy, there is heated controversy in the possibility of completing radical gastrectomy with membrane anatomical concept for gastric cancer. We believe that if neoadjuvant therapy pushes mesenteric cancer cell back into the mesentery, theoretically membrane anatomy combined with neoadjuvant therapy is beneficial to the treatment efficacy of advanced gastric cancer. However, membrane anatomy has two important problems when combined with neoadjuvant therapy: (1) After neoadjuvant chemotherapy, there are varying degrees of edema around the stomach tissue, which will affect the visualization of anatomic planes. In addition, because the patients' coagulation function is damaged to a certain extent, it is difficult to avoid bleeding or minimize bleeding during the operation. Therefore, it is still controversial whether the patients with gastric cancer after neoadjuvant chemotherapy can undergo radical gastrectomy with membrane anatomy. (2) For patients with complete pathological remission, whether to obtain the maximum rate of pathological remission through intensive neoadjuvant therapy, or to obtain the survival benefit of patients with membrane anatomy surgery in clinic is still controversial. Faced with these confusions, multi-center clinical researches on the application of membrane anatomy surgery after neoadjuvant therapy is the only solution.

[Total mesorectal excision with preservation of Denonvilliers' fascia (iTME) based on membrane anatomy].

Total mesorectal excision (TME) has been advocated as the golden standard of mid-low rectal cancer surgery for nearly 30 years. However, the complication of postoperative urinary and sexual dysfunctions due to intraoperative nerve injury has yet to be improved. Based on the concept of membrane anatomy, we carried out a systematic study on the important membrane anatomical structure anterior to the rectum--Denonvilliers' fascia. From multiple aspects including anatomy, physiology, histochemistry and surgical practice, we verified the importance of Denonvilliers' fascia for TME surgery in prevention of intraoperative nerve injury and postoperative urogenital dysfunction. Moreover, based on anatomical study of the surgical marker line of Denonvilliers' fascia (Wei's line) and surgical plane, we proved that total mesorectal excision with preservation of Denonvilliers' fascia (iTME) was feasible and practical. Therefore, we conducted a large multicentric randomized controlled trial (RCT). The mid-term result demonstrated that compared with traditional TME surgery, iTME was more effective in reducing the incidence of postoperative urinary and sexual dysfunctions in male patients with mid-low rectal cancer, without sacrifice of short-term tumor radical outcome. We believe that the final RCT result of iTME, based on membrane anatomy, will provide solid evidence for the update of concepts of rectal cancer surgery.