Variaciones anatómicas en la vascularización del colon derecho y su implicancia en la escisión completa del mesocolon con linfadenectomía D3. Estudio de corte transversal / Anatomical variations in right colon vascularization: its implication in complete mesocolic excision with D3 lymphadenectomy. A cross-sectional study

Introducción: La escisión completa del mesocolon con linfadenectomía D3 (CME-D3) mejora los resultados de los pacientes operados por cáncer del colon. Reconocer adecuadamente la anatomía vascular es fundamental para evitar complicaciones. Objetivo: El objetivo primario fue determinar la prevalencia de las variaciones anatómicas de la arteria mesentérica superior (AMS) y sus ramas en relación a la vena mesentérica superior (VMS). El objetivo secundario fue evaluar la asociación entre las distintas variantes anatómicas y el sexo y la etnia de lo pacientes. Diseño: Estudio de corte transversal. Material y métodos: Se incluyeron 225 pacientes con cáncer del colon derecho diagnosticados entre enero 2017 y diciembre de 2020. Dos radiólogos independientes describieron la anatomía vascular observada en las tomografías computadas. Según la relación de las ramas de la AMS con la VMS, la población fue dividida en 2 grupos y subdividida en 6 (1a-c, 2a-c). Resultados: La arteria ileocólica fue constante, transcurriendo en el 58,7% de los casos por la cara posterior de la VMS. La arteria cólica derecha, presente en el 39,6% de los pacientes, cruzó la VMS por su cara anterior en el 95,5% de los casos. La variante de subgrupo más frecuente fue la 2a seguida por la 1a (36,4 y 24%, respectivamente). No se encontró asociación entre las variantes anatómicas y el sexo u origen étnico. Conclusión: Las variaciones anatómicas de la AMS y sus ramas son frecuentes y no presentan un patrón predominante. No hubo asociación entre las mismas y el sexo u origen étnico en nuestra cohorte. El reconocimiento preoperatorio de estas variantes mediante angiotomografía resulta útil para evitar lesiones vasculares durante la CME-D3. (AU)

Background: Complete mesocolic excision with D3 lymphadenectomy (CME-D3) improves the outcomes of patients operated on for colon cancer. Proper recognition of vascular anatomy is essential to avoid complications. Aim: Primary outcome was to determine the prevalence of anatomical variations of the superior mesenteric artery (SMA) and its branches in relation to the superior mesenteric vein (SMV). Secondary outcome was to evaluate the association between these anatomical variations and sex and ethnicity of the patients. Design: Cross-sectional study. Material and methods: Two hundred twenty-fivepatients with right colon cancer diagnosed between January 2017 and December 2020 were included. Two independent radiologists described the vascular anatomy of computed tomography scans. The population was divided into 2 groups and subdivided into 6 groups (1a-c, 2a-c), according to the relationship of the SMA and its branches with the SMV. Results: The ileocolic artery was constant, crossing the SMV posteriorly in 58.7% of the cases. The right colic artery, present in 39.6% of the patients, crossed the SMV on its anterior aspect in 95.5% of the cases. The most frequent subgroup variant was 2a followed by 1a (36.4 and 24%, respectively). No association was found between anatomical variants and gender or ethnic origin. Conclusions: The anatomical variations of the SMA and its branches are common, with no predominant pattern. There was no association between anatomical variations and gender or ethnic origin in our cohort. Preoperative evaluation of these variations by computed tomography angi-ography is useful to avoid vascular injuries during CME-D3. (AU)

Anatomical classification of and laparoscopic surgery for left-sided colorectal cancer with persistent descending mesocolon / 中华胃肠外科杂志

Objective: To investigate anatomical morphology and classification of persistent descending mesocolon (PDM) in patients with left-sided colorectal cancer, as well as the safety of laparoscopic radical surgery for these patients. Methods: This is a descriptive study of case series. Relevant clinical data of 995 patients with left colon and rectal cancer who had undergone radical surgery in Fujian Medical University Union Hospital from July 2021 to September 2022 were extracted from the colorectal surgery database of our institution and retrospectively analyzed. Twenty-four (2.4%) were identified as PDM and their imaging data and intra-operative videos were reviewed. We determined the distribution and morphology of the descending colon and mesocolon, and evaluated the feasibility and complications of laparoscopic surgery. We classified PDM according to its anatomical characteristics as follows: Type 0: PDM combined with malrotation of the midgut or persistent ascending mesocolon; Type 1: unfixed mesocolon at the junction between transverse and descending colon; Type 2: PDM with descending colon shifted medially (Type 2A) or to the right side (Type 2B) of the abdominal aorta at the level of the origin of the inferior mesentery artery (IMA); and Type 3: the mesocolon of the descending-sigmoid junction unfixed and the descending colon shifted medially and caudally to the origin of IMA. Results: The diagnosis of PDM was determined based on preoperative imaging findings in 9 of the 24 patients (37.5%) with left-sided colorectal cancer, while the remaining diagnoses were made during intraoperative assessment. Among 24 patients, 22 were male and 2 were female. The mean age was (63±9) years. We classified PDM as follows: Type 0 accounted for 4.2% (1/24); Type 1 for 8.3% (2/24); Types 2A and 2B for 37.5% (9/24) and 25.0% (6/24), respectively; and Type 3 accounted for 25.0% (6/24). All patients with PDM had adhesions of the mesocolon that required adhesiolysis. Additionally, 20 (83.3%) of them had adhesions between the mesentery of the ileum and colon. Twelve patients (50.0%) required mobilization of the splenic flexure. The inferior mesenteric artery branches had a common trunk in 14 patients (58.3%). Twenty-four patients underwent D3 surgery without conversion to laparotomy; the origin of the IMA being preserved in 22 (91.7%) of them. Proximal colon ischemia occurred intraoperatively in two patients (8.3%) who had undergone high ligation at the origin of the IMA. One of these patients had a juxta-anal low rectal cancer and underwent intersphincteric abdominoperineal resection because of poor preoperative anal function. Laparoscopic subtotal colectomy was considered necessary for the other patient. The duration of surgery was (260±100) minutes and the median estimated blood loss was 50 (20-200) mL. The median number of No. 253 lymph nodes harvested was 3 (0-20), and one patient (4.2%) had No.253 nodal metastases. The median postoperative hospital stay was 8 (4-23) days, and the incidence of complications 16.7% (4/24). There were no instances of postoperative colon ischemia or necrosis observed. One patient (4.2%) with stage IIA rectal cancer developed Grade B (Clavien-Dindo III) anastomotic leak and underwent elective ileostomy. The other complications were Grade I-II. Conclusions: PDM is frequently associated with mesenteric adhesions. Our proposed classification can assist surgeons in identifying the descending colon and mesocolon during adhesion lysis in laparoscopic surgery. It is crucial to protect the colorectal blood supply at the resection margin to minimize the need for unplanned extended colectomy, the Hartmann procedure, or permanent stomas.

Membrane anatomy in right colon cancer: definition and identification of mesocolic completeness / 中华胃肠外科杂志

Complete mesocolic excision (CME) and D3 resection of right colon cancer have been widely implemented, but the definition and identification of the completeness of the mesentery have not been fully agreed, especially the dorsal and medial borders. In this paper, we proposed the dorsal fascia of the colonic mesentery as the dorsal border of the mesocolon and the line connecting the roots of the ileocolic artery and the middle colic artery (ICA-MCA line) as the medial border of the CME by systematically studying the relationship between the mesentery and the mesenteric bed from the theory of membrane anatomy, combined with surgical experience and in-depth review of ontogenetic anatomy. We also proposed the visible "superior mesenteric vein notch" and "middle colic artery triangle" on surgical specimens as identifiers of mesocolic completeness.

A decade's review for membrane anatomy: the setting,events in it, order formed by primary fascia and serous membrane / 中华胃肠外科杂志

The successful report of total mesorectal excision (TME)/complete mesocolic excision (CME) has encouraged people to apply this concept beyond colorectal surgery. However, the negative results of the JCOG1001 trial denied the effect of complete resection of the "mesogastrium" including the greater omentum on the oncological survival of gastric cancer patients. People even believe that the mesentery is unique in the intestine, because they have a vague understanding of the structure of the mesentery. The discovery of proximal segment of the dorsal mesogastrium (PSDM) proved that the greater omentum is not the mesogastrium, and further revised the structure (definition) of the mesentery and revealed its container characteristics, i.e. the mesentery is an envelope-like structure, which is formed by the primary fascia (and serosa) that enclose the tissue/organ/system and its feeding structures, leading to and suspended on the posterior wall of the body. Breakdown of this structure leads to the simultaneous reduction of surgical and oncological effects of surgery. People quickly realized the universality of this structure and causality which cannot be matched by the existing theories of organ anatomy and vascular anatomy, so a new theory and surgical map- membrane anatomy began to form, which led to radical surgery upgraded from histological en bloc resection to anatomic en bloc resection.

A new insights of mesorectum / 中华胃肠外科杂志

Total mesorectal excision (TME) represents the gold standard for radical resection in rectal cancer. The development in radiology and laparoscopic surgical equipment and the advancement in technology have led to a deepened understanding of the mesorectum and its surrounding structures. Both the accuracy of preoperative staging and the preciseness of the planes of TME surgical dissection have been enhanced. The postoperative local recurrence rate is reduced and the long-term survival of rectal cancer patients is improved. The preservation of the pelvic autonomic nervous system maintains the patient's urinary and sexual functions to the greatest extent possible, which in turn improves the patient's postoperative quality of life. A thorough understanding of the anatomy of the mesorectum and its surrounding structures is a prerequisite for successful TME. Herein, we review the basic concepts and the anatomy of the mesorectum in the current literature. Some important clinical issues are also discussed systematically in terms of imaging, surgery, and pathology.

Medial border of D3 lymphadenectomy for right colon cancer / 中华胃肠外科杂志

The extent of D3 lymphadenectomy for right colon cancer, especially the medial border of central lymph node dissection remains controversial. D3 lymphadenectomy and complete mesocolon excision (CME) are two standard procedures for locally advanced right colon carcinoma. D3 lymphadenectomy determines the medial border according to the distribution of the lymph nodes. The mainstream medial border should be the left side of superior mesenteric vein (SMV) according to the definition of D3, but there are also some reports that regards the left side of superior mesenteric artery (SMA) as the medial border. In contrast, the CME procedure emphasizes the beginning of the colonic mesentery and the left side of SMA should be considered as the medial border. Combined with the anatomical basis, oncological efficacy and technical feasibility of D3 lymph node dissection, we think that it is safe and feasible to take the left side of SMA as the medial boundary of D3 lymph node dissection. This procedure not only takes into account the integrity of mesangial and regional lymph node dissection, but also dissects more distant lymph nodes at risk of metastasis. It has its anatomical basis and potential oncological advantages. However, at present, this technical concept is still in the exploratory stage in practice, and the related clinical evidence is not sufficient.

Anatomical observation of the right retroperitoneal fascia and its clinical significance in complete mesocolic excision for right colon cancer / 中华胃肠外科杂志

Objective: To investigate the anatomic characteristics of the right retroperitoneal fascia and its surgical implementation while performing complete mesocolic excision (CME) for right colon cancer. Methods: A descriptive study was carried out. (1) Clinicopathological data and surgical videos of 17 non-consecutive patients undergoing laparoscopic right hemicolectomy (extended right hemicolectomy) with CME for right colon cancer at Department of Colorectal Surgery of Union Hospital, Fujian Medical University between January 2020 and October 2020 were retrospectively collected. The construction of right retroperitoneal fascia was observed from caudal dorsal direction and caudal ventral direction. (2) Three postoperative specimens from 3 cases undergoing laparoscopic right hemicolectomy with CME for right colon cancer in June 2020 were prospectively included to observe anatomy and examine histology. (3) Five abdominal cadaver specimens from the Department of Anatomy of Fujian Medical University were enrolled, including 3 males and 2 females. Anatomical observation and histological studies were performed from the cranial approach and the caudal dorsal approach. Masson staining was used to examine the histology. Results: (1) Surgical video observation: The typical structure of right retroperitoneal fascia could be observed in all the 17 patients. The fascia was a rigid barrier between the posterior space of the ascending colon and the anterior pancreaticoduodenal space behind the transverse colon. The right retroperitoneal fascia should be sharply cut to communicate between the two spaces to avoid entering the right mesocolon by mistake. The severed ventral stump of the right retroperitoneal fascia ran along the dorsal side of the right hemicolon to the lateral side, and the dorsal stump covered the level of the duodenum caudally, and continued to move downward, covering the surface of Gerota's fascia. (2) Observation of 3 surgical specimens: The dorsal side of the right mesocolon was smooth and intact, which could be anchored in the corresponding area of the lateral edge of the duodenum. The ventral stump of the right retroperitoneal fascia could be seen, which attached to the dorsal side of the right mesocolon semi-circularly. Masson staining observation: The ventral stump of the right retroperitoneal fascia ran cephalad, fused with the dorsal side of the right mesocolon tightly and curled. The caudal side of confluence and the dorsal side of the right mesocolon presented a bilobed structure. (3) Anatomy of 5 cadaveric specimens: The right retroperitoneal fascia was a thin fascia structure, which was a rigid barrier between the anterior pancreaticoduodenal space behind the transverse colon and the posterior space of the ascending colon. The ventral stump of the right retroperitoneal fascia (including the dorsal side of the right mesocolon), the dorsal stump of the right retroperitoneal fascia (including part of the duodenal wall) and the dorsal side of the right mesocolon were retrieved for histological examination. The ventral stump of the right retroperitoneal fascia fused with the dorsal side of the right mesocolon by the cephalic side, and the dorsal side of the right hemi-mesocolon on the fusion level by caudal side gradually separated into a double-layer loose fascial structure. The dorsal stump of the right retroperitoneal fascia covered the surface of the duodenum level, moved on from the ventral side to the surface of the prerenal fascia, and continued to the caudal side. Conclusions: The right retroperitoneal fascia is a rigid barrier between the anterior pancreaticoduodenal space behind the transverse colon and the posterior space of the ascending colon. The Toldt fascia formed by fusion with the dorsal lobe of the right colon travels to the edge of the descending and horizontal part of the duodenum and separates again. The right retroperitoneal fascia is attached to the edge of the duodenum, reversing and running on the surface of the prerenal fascia, while the dorsal lobe of the right colon runs in front of the pancreas and duodenum, and shifts to the pancreaticoduodenal fascia. During the operation, this fascia should be identified and cut to penetrate the anterior pancreaticoduodenal space behind the transverse colon and the posterior ascending colon space, which helps to ensure the integrity of the dorsal side of the right hemi-mesocolon.

Anatomical observation of the left parietal peritoneum and its clinical significance in left retro-mesocolic space dissection / 中华胃肠外科杂志

Objective: To investigate the anatomic characteristics of the left parietal peritoneum and its surgical implementation while dissecting in left retro-mesocolic space. Methods: A descriptive case series research methods was used. (1) surgical videos of 35 patients who underwent laparoscopic radical resection (complete mobilization of splenic flexure) of colorectal cancer in Union Hospital of Fujian Medical University between January 2018 and December 2018 were reviewed; (2) four specimens after radical resection of rectal cancer performing in June 2020 were prospectively enrolled and reviewed; (3) five specimens of left parietal peritoneum from 5 cadaveric abdomen (3 males and 2 females) were enrolled and reviewed as well; Tissues of 3 unseparated regions, namely the root of the inferior mesenteric artery (IMA), the medial region and the lateral region (including kidney tissue), from above the 5 cadaveric abdominal specimens were selected to perform Masson staining and histopathological examination. Results: (1) Surgical video observation: "Staggered layer phenomenon" and typical left parietal peritoneum was found in 77.1% (27/35) of patients when the left retro-mesocolic space was separated from the lateral and central approaches. The left parietal peritoneum presented as a rigid fascia barrier between the lateral and central approaches, which was a translucent dense connective tissue fascia. After the splenic flexure were completely mobilized, the left parietal peritoneum stump continued to the cephalic side. (2) Observation of 4 surgical specimens: The dorsal side of the left mesocolon specimen was studied, and the left parietal peritoneum stump edge was identified. The outside of the stump edge was the left hemicolon dorsal layer, which was continuously downward to the rectal fascia propria. (3) Cadaveric abdominal specimens: The left retro-mesocolic space was separated through lateral and central approaches, and the rigid fascia barrier, essentially the left parietal peritoneum and Gerota fascia, was encountered. Cross-section view showed that the left parietal peritoneum could be further detached from the dorsal layer of the left mesocolon from the outside, but could not be further detached from the inside out. (4) Histological examination: There was no obvious fascia structure in the IMA root region, while outside the IMA root region, the left bundle of inferior mesenteric plexus penetrating Gerota fascia was observed. There were 4 layers of fascias in the medial region, including the ventral layer of the left mesocolon, the dorsal layer of the left mesocolon, left parietal peritoneum and Gerota fascia. Small vessels were observed between the dorsal layer of the left mesocolon and the left parietal peritoneum. In lateral region, renal tissue and renal fascia were observed. Three layers of fascia structures were observed clearly under high power field, including the dorsal layer of the left mesocolon, left parietal peritoneum, and Gerota fascia. Conclusions: The left parietal peritoneum is the anatomical basis of the "staggered layer phenomenon" from the lateral or central approaches during the separation of left retro-mesocolic space. The small vessels in the dissection plane are the anatomical basis of intraoperative microbleeding, which need pre-coagulation. The central part of Gerota fascia is penetrated by the branches of the inferior mesenteric plexus, which results in a relatively dense surgical plane. Thus, during the dissection through the central approach, it is easy to involve in wrong surgical plane by deeper dissection.

Radical surgery for colon cancer guided by membrane anatomy theory / 中华胃肠外科杂志

Like other solid tumors, colon cancer surgery has undergone a century-old journey from lumpectomy to organ resection and then to lymphadenectomy. From the Toldt fascia to complete mesenteric resection, and from local resection to D3 radical treatment, local recurrence rates have been reduced, but remain a nuisance to surgeons and patients. Based on the theory of membrane anatomy, radical surgery for colon cancer will focus more on removing the mesocolon from the mesentery bed while maintaining the integrity of the posterior fascia to avoid the occurrence of "fifth metastasis" as much as possible. Thanks to the membrane anatomy theory, its strong reproducibility and replicability, a new phase of colorectal surgery is on the horizon.

Holistic view of surgery based on membrane anatomy for gastrointestinal tumor / 中华胃肠外科杂志

The mesentery is a continuous unity and the operation of digestive carcinoma is the process of mesenteric resection. This paper attempts to simplify the formation process of all kinds of fusion fascia in the process of digestive tract embryogenesis, and to illuminate the continuity of fusion fascia with a holistic concept. This is helpful for beginners to reversely dissect the fusion fascia and maintain the correct surgical plane during operation, and to achieve the purpose of complete mesenteric resection.

Risk factors and prevention measures of anastomotic leak after right hemicolectomy for cancer / 中华胃肠外科杂志

The incidence of anastomotic leak after right hemicolectomy for cancer is relatively low, but it may be misjudged. In recent years, the results of some multi-center or nationwide registration studies in Europe have shown that the incidence of anastomotic leak is significantly higher than that of eastern countries. The reasons of these differences may be the different nature of the studies, the lack of rigor in diagnostic criteria or diagnostic methods, the difference in the level of specialization of hospitals or surgeons, and so on. Timely treatment of preoperative comorbidities, reasonable selection of preoperative bowel preparation and anastomotic technique/method might reduce the occurrence of anastomotic leak. The current evidence shows complete mesocolic excision (CME) does not increase the risk of anastomotic leak. The clinical features of ileo-colic anastomotic leak are different from those of rectal surgery. The mild cases can be treated conservatively, and the severe cases are suggested to receive timely diverting ileostomy.

Similarities and differences between D3 lymphadenectomy and complete mesocolic excision of right hemicolonectomy / 中华胃肠外科杂志

D3 lymphadenectomy and complete mesocolic excision (CME) for colon cancer, which have been introduced to China for more than 10 years, are two major surgical principles worldwide. However, there are still many different opinions and misunderstandings about the core principles of D3 and CME, especially the similarities and differences between them. However, few articles have been published to discuss these issues specifically. Domestic scholars' understandings about D3 lymphadenectomy and CME for right hemicolectomy are quite different. Two different concepts including "D3/CME" and "D3+CME" have become mainstream views. The former equate D3 with CME and the latter seems to regard them as totally different principles. There is no consensus on which one is more reasonable. Therefore, this article aims to discuss the similarities and differences between D3 and CME for right hemicolectomy in perspectives of the theoretical background, surgical principles, extent of surgery and oncological outcomes. We believed that D3 and CME do not belong to the same concept, and that the scope of CME surgery for right-sided colon cancer is greater than and includes the scope of D3 surgery, and that D3 and CME are not complementary.

Intraoperative anatomical observation of mesentery morphology of colonic splenic flexure / 中华胃肠外科杂志

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.

Is total mesocolon excision necessary? A systematic review / Excisão total do mesocolon é necessário? Uma revisão sistemática

ABSTRACT Complete mesocolon excision is an alternative in the treatment of neoplasias. The open technique was initially described for the procedure; however, it has some limitations. In this scenario, videolaparoscopic surgery is a minimally invasive alternative; however, its use in complete mesocolon excision is controversial. This study aimed to evaluate the results of videolaparoscopic complete mesocolon excision. A systematic review of the literature was performed for this study. Nine articles were selected, comprising 860 patients. The surgical results demonstrate the quality of the videolaparoscopic technique, which presents low morbidity and mortality and high survival rates after five years. Videolaparoscopy is a safe and effective method for complete mesocolon excision.

RESUMO A excisão completa do mesocolon constitui-se como alternativa para o tratamento de neoplasias. A técnica aberta foi descrita inicialmente para a realização do procedimento, no entanto apresenta algumas limitações. Nesse cenário a cirurgia por videolaparoscopia apresenta-se como alternativa minimamente invasiva, no entanto sua empregabilidade para a excisão completa do mesocolon é motivo de controvérsia. O objetivo deste trabalho é estudar os resultados oriundos da cirurgia por videolaparoscopia aplicada à excisão completa do mesocolon. A revisão sistemática da literatura foi utilizada para a realização deste estudo. Nove artigos científicos foram selecionados, compreendendo 860 pacientes. Os resultados cirúrgicos demonstram a qualidade da técnica por videolaparoscopia, que apresenta baixa morbidade e mortalidade e com altas taxas de sobrevivência após cinco anos. A videolaparoscopia aplicada à excisão completa do mesocolon apresenta qualidade que possibilita a realização da excisão completa do mesocolon de forma segura e eficaz.

Internal hernia through mesocolon defect after left laparoscopic colectomy / Hérnia interna pelo defeito mesocólico após colectomia esquerda laparoscópica

ABSTRACT Introduction: The development of internal hernias due to the mesocolon defect after laparoscopic colectomy is a rare complication with only 39 cases described. There are controversies whether the closure of the defect of the mesocolon after resection of the colon could prevent the development of this complication. Objective: To describe a case of intestinal obstruction due to internal hernia through the mesocolon defect after laparoscopic rectosigmoidectomy and to perform a literature review. Case report: A 59-year-old woman was hospitalized for laparoscopic rectosigmoidectomy due to an adenocarcinoma located in the rectosigmoid junction. She underwent a rectosigmoidectomy by laparoscopy, with an extracorporeal mechanical anastomosis, without closure of the mesocolon defect. In the fifth postoperative day the patient presented an intestinal obstruction due to an internal hernia through the mesocolon defect confirmed by computerized tomography. During the exploratory laparotomy approximately 120 cm jejunum was identified through the mesocolon defect. The reduction of herniated small bowel was done without the need of intestinal resection. The mesocolon defect was corrected by continuous suture. After the reoperation, the patient presented a favorable recovery being discharged on the fifth day. Conclusion: Intestinal obstruction due to internal hernia after laparoscopic rectosigmoidectomy is a rare postoperative complication that can be avoided by the adequate closure of the mesocolon defect.

RESUMO Introdução: O desenvolvimento de hérnias internas pelo defeito mesocólico após a realização de colectomia laparoscópica é uma complicação rara com apenas 39 casos descritos. Existem controvérsias se fechamento do defeito após a ressecção do cólon preveniria o desenvolvimento desta complicação. Objetivo: Descrever um caso de obstrução intestinal por hérnia interna pelo defeito mesocólico, após retossigmoidectomia laparoscópica e revisar a literatura relacionada ao tema. Relato do caso: Mulher, 59 anos foi internada para realizar ressecção cirúrgica de adenocarcinoma localizado na junção retossigmoideana. Foi submetida à retossigmoidectomia laparoscópica, com confecção de anastomose mecânica extracorpórea. O defeito mesocólico não foi corrigido no final do procedimento. No quinto dia de pós-operatório, a doente apresentou quadro de obstrução intestinal cuja tomografia computadorizada identificou presença de hérnia interna pelo defeito do mesocólon. Na laparotomia exploradora identificou-se que aproximadamente 120 cm de alças jejunais estavam herniadas através do defeito mesocólico. Realizou-se a redução do intestino delgado herniado sem necessidade de ressecção intestinal. O defeito foi corrigido por sutura contínua. Após a reoperação a doente apresentou evolução favorável recebendo alta no quinto dia. Conclusão: Obstrução intestinal após retossigmoidectomia laparoscópica consequente à formação de hérnia interna é complicação pós-operatória rara, com alta mortalidade, que pode ser evitada pelo fechamento criterioso do defeito do mesocólico.

Ischemic Necrosis Caused by Retroanastomotic Hernia after Subtotal Gastrectomy / 대한소화기학회지

After gastrojejunostomy, a small space can occur between the jejunum at the anastomosis site, the transverse mesocolon, and retroperitoneum, which may cause an intestinal hernia. This report presents a rare case of intestinal ischemic necrosis caused by retroanastomotic hernia after subtotal gastrectomy. A 56-year-old male was admitted to Kangwon National University Hospital with melena, abdominal pain, and nausea. His only relevant medical history was gastrectomy due to stomach cancer. Endoscopic findings revealed subtotal gastrectomy with Billroth-II reconstruction and a bluish edematous mucosal change with necrotic tissue in afferent and efferent loops including the anastomosis site. Abdominopelvic CT showed strangulation of proximal small bowel loops due to mesenteric torsion and thickening of the wall of the gastric remnant. Emergency laparotomy was performed. Surgical findings revealed the internal hernia through the defect behind the anastomosis site with strangulation of the jejunum between 20 cm below the Treitz ligament and the proximal ileum. Roux-en-Y anastomosis was performed, and he was discharged without complication. Retroanastomotic hernia, also called Petersen's space hernia, is a rare complication after gastric surgery, cannot be easily recognized, and leads to strangulation.

A single center retrospective study on surgical efficacy of T3NxM0 middle-low rectal cancer without neoadjuvant therapy / 中华胃肠外科杂志

OBJECTIVE@#To investigate the surgical efficacy and prognostic factors of T3NxM0 middle-low rectal cancer without neoadjuvant therapy.@*METHODS@#Clinical data of patients with middle-low rectal cancer undergoing TME surgery with T3NxM0 confirmed by postoperative pathology at Colorectal Surgery Department of Changhai Hospital from January 2008 to December 2010 were analyzed retrospectively.@*INCLUSION CRITERIA@#(1)no preoperative neoadjuvant chemoradiotherapy (nCRT); (2) complete preoperative evaluation, including medical history, preoperative colonoscopy or digital examination, blood tumor marker examination, and imaging examination; (3) distance between tumor lower margin and anal verge was ≤ 10 cm; (4) negative circumferential resection margin (CRM-). Finally, a total of 331 patients were included in this study. According to the number of metastatic lymph node confirmed by postoperative pathology, the patients were divided into N0 group without regional lymph node metastasis (190 cases) and N+ group with regional lymph node metastasis (141 cases). The perioperative conditions, local recurrence, distant metastasis and prognostic factors were analyzed.@*RESULTS@#Compared to N0 group in the perioperative data, N+ group had higher ratio of tumor deposit [29.8%(42/141) vs. 0, χ²=64.821, P0.05). The median follow-up period was 73.4 months. The merged 5-year local recurrence rate was 2.7%(9/331), 5-year distant metastasis rate was 23.3% (77/331), 5-year disease-free survival (DFS) rate was 73.4%, and 5-year overall survival (OS) rate was 77.2%. Multivariate analysis showed that lymph node metastasis (HR=3.120, 95%CI: 1.918 to 5.075, P<0.001), nerve invasion (HR=0.345, 95%CI: 0.156 to 0.760, P=0.008) and vascular invasion (HR=0.428, 95%CI: 0.189 to 0.972, P=0.043) were independent risk factors for DFS in patients with T3NxM0 rectal cancer after operation. Preoperative carcinoembryonic antigen level (HR=1.858, 95%CI:1.121 to 3.079, P=0.016), lymph node metastasis (HR=3.320, 95%CI: 1.985 to 5.553, P<0.001) and nerve invasion (HR=0.339, 95%CI: 0.156 to 0.738, P=0.006) were independent risk factors for OS in patients with T3NxM0 rectal cancer after operation.@*CONCLUSIONS@#Optimal local control rate of middle-low rectal cancer patients with T3NxM0 and CRM- can be achieved by standard TME surgery alone. For patients with preoperative elevated blood carcinoembryonic antigen level, regional lymph node metastasis, or neurovascular invasion confirmed by pathology after surgery, adjuvant chemoradiotherapy should be actively applied after surgery to improve prognosis.

Investigation on the integrity of mesorectal specimens of transanal total mesorectal excision / 中华胃肠外科杂志

Total mesorectal excision (TME) has become the gold standard for mid-low rectal cancer surgery. However, for some patients with obesity and narrow pelvis, there are great challenges in both open and laparoscopic surgery. Transanal total mesorectal excision (taTME) uses a transanal approach, in " bottom-up" direction, which reduces the difficulty of distal mesorectal excision and may improve the quality of the TME specimen. The taTME provides a direct sight of the tumor and the distal resection margin is more precise. However, whether taTME can achieve complete total mesorectal excision, especially for mid-rectal cancer, is still controversial. This study compares the quality and integrity of mesorectum among open surgery, laparoscopic surgery, and taTME surgery according to TME principles and quality evaluation criteria of TME specimen. In conclusion, the integrity of mesorectum of taTME specimens for low-rectal cancer is good. But for the mid-rectal cancer, the integrity of mesorectum of taTME specimens and long-term efficacy are still controversial and need high-level evidence support.

Topographical anatomy of the greater omentum and transverse mesocolon: a study using human fetuses / 대한해부학회지

Metastasis and dissection of infrapyloric lymph node in the colon cancer of hepatic flexure / 中华胃肠外科杂志

Colon cancer is one of the most common malignancies of the alimentary tract, and one main metastatic route is lymph node metastasis. Thorough dissections of regional lymph nodes is one of the core surgical treatment of right colon cancer. D3 lymphadenectomy and complete mesocolic excision (CME) are generally accepted surgical methods for right colon cancer, which can improve the standardization of surgery, improve the quality of tumor resection, and provide more lymph nodes dissectal. Colon cancer of hepatic flexure is likely to have metastasis of the infrapyloric lymph nodes (No.206), which are not regional lymph nodes. Lymph node dissection of No.206 group belongs to extended right hemicolectomy, which involves many vascular variations and complicated peripheral anatomical structure. The theory of fascial surgery provides surgeons with anatomic basis and a clear understanding of the anatomical structure of the infrapyloric region, which is an important theoretical basis for the thorough dissection of lymph nodes in No.206 group, and can completely remove the mass, regional lymph nodes and adipose connective tissue, so as to achieve the goal of non-bleeding surgery. Lymph nodes in No.206 group were dissected, not just the visible lymph nodes, but the entire lymph nodes and lymphatic vessels in the region, including adipose tissue. Extended right hemicolectomy requires higher surgical techniques. The survival benefits of extended right hemicolectomy are not supported by high-level evidence. It is still controversial whether the infrapyloric lymph node dissection should become routine for colon cancer of hepatic flexure. In this article, the metastasis and dissection of infrapyloric lymph node in colon cancer of hepatic flexure is elucidated.