Hidatidosis mesentérica y hepática en la costa caribe colombiana. Reporte de caso / Mesenteric and hepatic hydatid disease on the Colombian Caribbean coast. Case report

Introducción. La hidatidosis o equinococosis es una zoonosis parasitaria que se adquiere al ingerir huevos de cestodos del género Echinococcus. El diagnóstico clínico raramente se hace en sitios no endémicos. La mayoría de los pacientes se encuentran asintomáticos y los hallazgos incidentales en los estudios de imágenes o en procedimientos quirúrgicos permiten la sospecha diagnóstica. Caso clínico. Paciente masculino de 70 años, residente en área rural del municipio de Puerto Libertador, departamento de Córdoba, Colombia, quien consultó por masa abdominal en epigastrio y mesogastrio, parcialmente móvil e indolora. Resultados. En cirugía se identificaron lesiones quísticas mesentérica y hepática. Después de la cirugía y mediante estudios de inmunohistoquímica, se confirmó el diagnóstico de quiste hidatídico. El paciente tuvo una evolución satisfactoria. Conclusión. La hidatidosis quística mesentérica y hepática sintomática es una enfermedad rara en sitios no endémicos, donde la cirugía constituye un pilar fundamental en el diagnóstico y tratamiento, sumado al manejo médico farmacológico.

Introduction. Hydatidosis or echinococcosis is a parasitic zoonosis that is acquired by ingesting eggs of cestodes of the genus Echinococcus. Clinical diagnosis is rarely made in non-endemic sites. Most patients are asymptomatic and incidental findings on imaging studies or surgical procedures allow for diagnostic suspicion. Clinical case. A 70-year-old male patient, resident in a rural area of the municipality of Puerto Libertador, department of Córdoba, Colombia, who consulted for an abdominal mass in the epigastrium and mesogastrium, partially mobile and painless. Results. In surgery, mesenteric and hepatic cystic lesions were identified. After surgery and through immunohistochemistry studies, the diagnosis of hydatid cyst was confirmed. The patient had a satisfactory evolution. Conclusion. Symptomatic mesenteric and hepatic cystic hydatidosis is a rare disease in non-endemic sites, where surgery constitutes a fundamental pillar in the diagnosis and treatment in addition to pharmacological medical management.

Teratoma mesentérico maduro en una mujer adulta: reporte de caso y revisión de la literatura / Mature mesenteric teratoma in an adult women: Case report and literature

Introducción. Los teratomas son neoplasias que surgen a partir de células germinales pluripotenciales y derivan de dos o más capas de células. Se clasifican en tumores maduros, que contienen tejidos bien diferenciados, o inmaduros, que contienen estructuras inmaduras y embrionarias. Su localización más frecuente son las gónadas; la ubicación mesentérica es infrecuente y se han descrito aproximadamente 40 casos en la literatura mundial. Dentro del abordaje diagnóstico y terapéutico, se emplea la tomografía computarizada y la resonancia magnética nuclear para caracterizar la lesión, evaluar la extensión intraabdominal y la relación con otras estructuras. El diagnóstico debe confirmarse mediante el examen histopatológico. Caso clínico. Paciente femenina de 56 años, con antecedente de carcinoma ductal infiltrante de mama izquierda en remisión, en estudios de seguimiento con hallazgo incidental en tomografía de abdomen de lesión abdominopélvica dependiente del mesenterio, contornos lisos y nivel grasa-líquido. Estudios de extensión con marcadores tumorales negativos. Resultados. Por la alta sospecha clínica e imagenológica de teratoma, fue llevada a resección quirúrgica de la lesión. El examen histopatológico confirmó el diagnóstico de teratoma quístico maduro del mesenterio. Conclusión. El teratoma mesentérico es una entidad clínica rara, que debe ser considerado como uno de los diagnósticos diferenciales de una masa abdominal con efecto compresivo. El diagnóstico se basa principalmente en el examen clínico y los hallazgos imagenológicos. La escisión quirúrgica temprana es el pilar del tratamiento; el abordaje laparoscópico o abierto depende de las características clínicas y la experiencia del cirujano.

Background. Teratomas are neoplasms that arise from pluripotent germ cells, derived from two or more layers of germ cells. They are classified as mature tumors (cystic or solid), which contain well-differentiated tissues, or as immature tumors, which contain immature and embryonic structures. Its most frequent location is the female and male gonads; the mesenteric location is rare and approximately 40 cases have been described in the world literature. Within the diagnostic and therapeutic approach, computed tomography and magnetic resonance imaging are used to characterize the lesion, assess intra-abdominal extension and the relationship with other structures. The diagnosis must be confirmed by histopathological examination. Clinical case. A 56-year-old female patient with a history of infiltrating ductal carcinoma of the left breast in remission. In follow-up studies, incidental abdominal tomography finding of an abdominopelvic lesion dependent on the mesentery at the level of the mesogastrium, smooth contours with fat-liquid level. Extension studies with negative tumor markers. Results. Due to high clinical and imaging suspicion of teratoma, the patient was taken to resection of the lesion. Histopathological examination confirmed the diagnosis of mature cystic teratoma of the mesentery. Conclusion. Mesenteric teratoma is a rare clinical entity and is considered one of the differential diagnoses of an abdominal mass with a compressive effect. Diagnosis is mainly based on clinical examination and imaging findings. Early surgical excision is the mainstay of treatment; laparoscopic or open approach depends on the clinical characteristics and the experience of the surgeon.

Development of membrane anatomy theory in gastric cancer surgery / 中华胃肠外科杂志

In the past decade, the concept of membrane anatomy has been gradually applied in gastric cancer surgery. Based on this theory, D2 lymphadenectomy plus complete mesogastric excision (D2+CME) has been proposed, which has been demonstrated to significantly reduce intraoperative bleeding and intraperitoneal free cancer cells during surgery, decrease surgical complications, and improve survival. These results indicate that membrane anatomy is feasible and efficacious in gastric cancer surgery. In this review, we will describe the important contents of membrane anatomy, including "Metastasis V"(2013, 2015), proximal segmentation of dorsal mesogastrium (2015), D2+CME procedure (2016), "cancer leak"(2018), and surgical outcomes of D2+CME (2022).

Landmark vessel in membrane anatomy-based colorectal surgery / 中华胃肠外科杂志

The theory of membrane anatomy has been widely used in the field of colorectal surgery. The key point to perform high quality total mesorectal excision (TME) and complete mesocolic excision (CME) is to identify the correct anatomical plane. Intraoperative identification of the various fasciae and fascial spaces is the key to accessing the correct surgical plane and surgical success. The landmark vessels refer to the small vessels that originate from the original peritoneum on the surface of the abdominal viscera during embryonic development and are produced by the fusion of the fascial space. From the point of view of embryonic development, the abdominopelvic fascial structure is a continuous unit, and the landmark vessels on its surface do not change morphologically with the fusion of fasciae and have a specific pattern. Drawing on previous literature and clinical surgical observations, we believe that tiny vessels could be used to identify various fused fasciae and anatomical planes. This is a specific example of membrane anatomical surgery.

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.

Application of membrane anatomy in hepatopancreatobiliary and splenic surgery / 中华外科杂志

Understanding of a variety of membranous structures throughout the body,such as the fascia,the serous membrane,is of great importance to surgeons. This is especially valuable in abdominal surgery. With the rise of membrane theory in recent years,membrane anatomy has been widely recognized in the treatment of abdominal tumors,especially of gastrointestinal tumors. In clinical practice. The appropriate choice of intramembranous or extramembranous anatomy is appropriate to achieve precision surgery. Based on the current research results,this article described the application of membrane anatomy in the field of hepatobiliary surgery,pancreatic surgery,and splenic surgery,with the aim of blazed the path from modest beginnings.

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.

Desmoid-type fibromatosis of the mesentery: a clinicopatho-logical and genetic analysis of 9 cases / 浙江大学学报·医学版

Nine cases of mesenteric desmoid-type fibromatosis were diagnosed and treated in Taizhou Hospital, Wenzhou Medical University between January 2010 and May 2022, including 2 females and 7 males, aged 16 to 59 years. The lesions were in the mesentery of small intestine with 7 cases, ileocecal junction with 1 cases and transverse colon with 1 case. The tumors had an unclear boundary and no envelope, the section was solid, gray and tough. The mean maximum diameter was (10.7±8.5) cm (range 3.5-33.0 cm). Microscopically, fusiform fibroblasts and myofibroblasts were parallel, bunched or staggered, buried in a large amount of extracellular collagen. The cell morphology was relatively consistent, without obvious atypia, and mitosis was rare. Immunohistochemistry showed that the tumor cells were positive for vimentin (9/9), β-catenin (9/9), while smooth muscle actin (5/9) stains were focally positive. Ki-67 proliferation index was 1%-10%. Cytokeratin Pan, S-100, STAT6, CD117, DOG1, CD34, desmin and anaplastic lymphoma kinase stains were negative. Genetic analysis showed that there were 7 cases of c.121G>A(p.Thr41Ala) mutation of CTNNB1 gene, 1 case of c.121G>A(p.Thr41Ala) and 1 case of c.134C>T(p.Ser45Phe) double mutation, and 1 case of wild type. Tumors were surgically resected in all 9 cases. Eight cases had no recurrence or metastasis, 1 case had recurrence 6 months later, and no recurrence or metastasis after additional surgical resection.

Hemangiolinfangioma mesentérico: reporte de un caso / Mesenteric hemangiolymphangioma: case report

El hemangiolinfangioma es un tipo muy raro de malformación del sistema vascular, caracterizado histológicamente por la presencia de vasos venosos y linfáticos dilatados quísticamente, cuyas células endoteliales de revestimiento son positivas para marcadores de inmunohistoquímica como CD31, CD34 y D2-40. El compromiso extenso retroperitoneal y del tracto gastrointestinal es infrecuente. Se presenta el caso de una paciente femenina de 24 años con antecedente de dolor pélvico crónico, con exacerbación de síntomas. El diagnóstico imagenológico mostró una masa retroperitoneal multiquística. Se hizo hemicolectomía derecha y resección de la masa, encontrándose que dicha lesión estaba íntimamente adherida al mesenterio con compromiso extenso del tracto gastrointestinal, y cuyo estudio histopatológico reveló un hemangiolinfangioma, con mejoría clínica posterior a la resección quirúrgica. Aportamos a la literatura mundial, la caracterización de los hallazgos clínicos, imagenológicos e histopatológicos de este tipo de malformaciones

Hemangiolymphangioma is a very rare type of malformation of the vascular system, characterized histologically by the presence of cystically dilated venous and lymphatic vessels, whose lining endothelial cells are positive for immunohistochemical markers such as CD31, CD34 and D2-40. Extensive retroperitoneal and gastrointestinal tract involvement is uncommon. We present the case of a 24-yearold female patient with a history of chronic pelvic pain with exacerbation of symptoms. The imaging diagnosis revealed a multicystic retroperitoneal mass. A right hemicolectomy and resection of the mass was performed, finding that the lesion was intimately adherent to the mesentery with extensive involvement of the gastrointestinal tract, and whose histopathological study revealed a hemangiolymphangioma, with clinical improvement after surgical resection. We contribute to the world literature with the characterization of the clinical, imaging and histopathological findings of this type of malformations

Inducible co-stimulatory molecules participate in mesenteric vascular endothelial-mesenchymal transition and sclerosis of mesenteric vessels in spontaneously hypertensive rats / 南方医科大学学报

OBJECTIVE@#To investigate the correlation of inducible co-stimulatory molecules (ICOS) with mesenteric vascular endothelial- mesenchymal transition (EndMT) and sclerosis in spontaneously hypertensive rats (SHR).@*METHODS@#Twenty 4-week-old WKY rats and 20 SHRs of the same strain were both randomly divided into 4 groups for observation at 4, 6, 10 and 30 weeks of age. ICOS expression frequency in rat spleen CD4+T cells was analyzed using flow cytometry, and the expressions of ICOS, VE-cad, α-SMA and Col3 mRNA in rat mesentery were detected by RT-PCR. The distributions of ICOS, IL-17A and TGF-β in rat mesentery were detected by immunohistochemistry. The levels of IL-17A and TGF-β in rat plasma were measured using ELISA. The morphological changes of rat mesenteric vessels were observed with Masson staining. Spearman or Pearson correlation analyses were used to evaluate the correlation between ICOS expression and the expressions of the markers of vascular EndMT and sclerosis.@*RESULTS@#Compared with the control WKY rats, the SHRs began to show significantly increased systolic blood pressure and ICOS expression frequency on CD4+T cells at 6 weeks of age (P < 0.05). In the SHRs, the mRNA and protein expressions of ICOS, α-SMA, Col3, IL-17A and TGF-β in the mesentery were significantly higher than those in control group (P < 0.05), while the mRNA and protein expressions of VE-cad started to reduce significantly at 10 weeks of age (P < 0.05). The plasma levels of IL-17A and TGF-β were significantly increased in SHRs since 6 weeks of age (P < 0.05) with progressive worsening of mesenteric vascular sclerosis (P < 0.05). ICOS mRNA and protein expression levels in the mesenteric tissues of SHRs began to show positive correlations with α-SMA and Col3 expression levels and the severity of vascular sclerosis at 6 weeks of age (P < 0.05) and a negative correlation with VE-cad expression level at 10 weeks (P < 0.05).@*CONCLUSION@#ICOS play an important pathogenic role in EndMT and sclerosis of mesenteric vessels in essential hypertension by mediating related immune responses.

Quiste mesentérico gigante como simulador de ascitis: reporte de un caso y revisión de la literatura / Giant mesenteric cyst mimicking ascites: a case report and review of the literature

Introducción. Los quistes mesentéricos son tumores poco frecuentes y usualmente benignos, que se diagnostican principalmente en la edad pediátrica, de manera incidental.Caso clínico. Se presenta el caso de una paciente de cuatro años de edad, con dificultad para acceso a servicio de salud por localización de su vivienda, quien cursa con un cuadro clínico de dos años de evolución de distensión abdominal progresiva, interpretada y manejada como ascitis. Se realizó una tomografía de abdomen en la que se documentó una lesión quística gigante, por lo que fue llevada a resección por laparotomía, con confirmación histopatológica de un quiste mesentérico. Discusión. Los quistes mesentéricos pueden tener cualquier localización en el mesenterio del tracto gastrointestinal. Su principal etiología es la proliferación anormal y benigna de tejido linfático mesentérico. Las manifestaciones clínicas van desde la ausencia de síntomas hasta el abdomen agudo. Dentro de los síntomas abdominales no agudos se encuentran masa abdominal indolora, dolor abdominal, distensión abdominal y signos clínicos que simulan ascitis. La resección completa del quiste mesentérico es considerada el tratamiento de elección; el abordaje laparoscópico o abierto dependerá de las características clínicas de cada paciente y la experiencia del cirujano tratante. Conclusión. Es importante que los cirujanos conozcan las principales características y el manejo de esta entidad, que una vez presente, puede simular un síndrome ascítico.

Introduction. Mesenteric cysts are rare and usually benign tumors, which are diagnosed incidentally, mainly in children.Clinical case. We present the case of a 4-year-old patient, with difficulty accessing health services due to the location of her home, who has a 2-year history of progressive abdominal distension, interpreted and managed as ascites. An abdominal tomography was performed in which a giant cystic lesion was documented. She underwent resection by laparotomy, with histopathological confirmation of a mesenteric cyst. Discussion. Mesenteric cysts can have any location in the mesentery of the gastrointestinal tract. Its main etiology is the abnormal and benign proliferation of mesenteric lymphatic tissue. Clinical manifestations range from the absence of symptoms to an acute abdomen. Non-acute abdominal symptoms include a painless abdominal mass, abdominal pain, abdominal distension, and clinical signs that mimic ascites. Complete resection of the mesenteric cyst is considered the treatment of choice; laparoscopic or open approach will depend on the clinical characteristics of each patient and the experience of the treating surgeon. Conclusion. It is important for surgeons to know the main characteristics and management of this entity, which once present, can mimic an ascites syndrome

Location of inferior mesentery artery ligation in rectal cancer surgery: how to make decisions based on available evidence / 中华胃肠外科杂志

There are still controversies as to the location of ligating the inferior mesenteric artery and the central lymph node dissection during rectal cancer surgery. The reason is that the level of evidence in this area is low. Existing studies are mostly retrospective, analyses or small-sample randomized controlled trials. These results showed no significant differences between high-ligation and low-ligation, in terms of anastomotic leakage and other short-term postoperative complications. Low-ligation seems better for the recovery of postoperative genitourinary function. Due to the low rate of central lymph node metastasis and many other confounding factors that affect the survival rate, it is difficult to conclude the survival benefits of ligation site or central node dissection. It is necessary to carry out some targeted, well-designed, large-scale randomized controlled trials to explain the related issues of inferior mesenteric artery ligation site and extent of central lymphadenectomy.

Mesenteric lengthening in pouch surgery: review of surgical techniques

Described for the first time in themedical literature in 1978 by Parks and Nicholls, total proctocolectomy with ileal-pouch anal anastomosis (IPAA) is nowadays the procedure of choice for patients with ulcerative colitis inwhom themedical therapy has, a selected group of patients with Crohń s disease, and for patients with familial adenomatous polyposis. Despite the advances in medical treatment regarding inflammatory bowel disease, up to 30% of patients still require surgery, and restorative proctocolectomy and IPAA are the mainstay of the surgical treatment. It is considered a demanding and technically-challenging procedure, with the main challenge being the performance of a tension-free IPAA; the main reason for failure of the tension-free anastomosis is a shortened mesentery. With particular attention to detail, sufficient length can be achieved to enable a safe anastomosis in most patients. Herein, we describe the available techniques to lengthen the mesentery of the ileal pouch to perform an easyto- reach tension-free anastomosis. (AU)

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.

Exploration of the theoretical system of membrane anatomy in colorectal surgery / 中华胃肠外科杂志

Despite the concept of membrane anatomy has been widely used in minimally invasive colorectal surgery, the definition of membrane anatomy and the establishment of membrane plane remain controversial. Therefore, it is difficult to establish a unified theoretical system of membrane anatomy. Through embryological studies and anatomical findings on the integrity and continuity of membranes, we try to discuss the theoretical system of membrane anatomy in colorectal surgery from three aspects: membrane anatomical system, membrane anatomical elements and membrane anatomical mechanism. The establishment of a unified theoretical system of membrane anatomy will not only contribute to the standardization operative procedures, but also to the establishment of uniform surgical standards for colorectal cancer.

Application of posterior gastric mesentery in laparoscopic gastric surgery / 中华胃肠外科杂志

The posterior gastric mesentery is one of the six mesenteries of the stomach in the membrane anatomy theory. It locates in the upper area of the pancreas, surrounds the posterior gastric vessels, and is adjacent to the short gastric mesentery by the left side, and is adjacent to the left gastric mesentery by the right side, which fixes the fundus body to the posterior abdominal wall of the upper area of pancreas. Due to its anatomical structure, in complete mesentery excision (CME)+D2 surgery, it is a surgical approach to deal with gastric mesentery in the upper area of pancreas; the second step of the "Huang's three-step method" corresponds to the posterior gastric mesentery in the theory of membrane anatomy. In the surgery of benign diseases of the stomach, laparoscopic sleeve gastrectomy (LSG) and laparoscopic Nissen fundoplication, if the short gastric vessels are difficult to be exposed and safely divided, we can dissect the posterior gastric mesentery firstly, and then hoist the fundus of the stomach in order to help dissection of the short gastric vessels. The membrane anatomy theory, as a frontier theory, provides us the new surgical perspectives and paths in gastric surgery.

Demonstration and significance on proximal segment of dorsal mesogastrium / 中华胃肠外科杂志

In radical gastrectomy, D2 systemic lymphadenectomy, which includes complete resection of the bursa sac and omentum, and D2 extended lymphadenectomy outside the bursa sac, is a standard procedure accepted by gastrointestinal surgeons generally. However, a series of clinical trials showed that both D2 extended lymphadenectomy and bursectomy could not improve oncologic benefit, but increase surgical risk. These findings showed a lot of conflicts in gastric cancer surgery, gastrointestinal surgery, even in oncological surgery. It was demonstrated that bursa sac and greater omentum were neither mesogastrium nor the proximal segment of dorsal mesogastrium (PSDM), which has been identified recently. Local physiological structures (such as blood vessels and lymphatic nodes) and pathological events (such as lymph nodes metastasis and metastasis V) only occur in mesentery in broad sense (i.e. PSDM). Broken PSDM during radical gastrectomy can result in cancer cell leakage into the operational field. Therefore, complete PSDM excision in the D2 field (D2+CME) is suggested as a better procedure for local advanced gastric cancer, which can get benefits not only in surgical hazard, but also in oncologic result. The results of PSDM research could lead to three changes: (1) resolving some long standing problems in gastric cancer surgery, gastrointestinal surgery, and even oncologic surgery; (2) opening an new era for finding and utilizing extra-intestinal mesentery in broad sense; (3) formulating the theory of membrane anatomy which may update, iterate and upgrade related information of classical anatomy, pathology, surgery and oncology.

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.

Scientific paradigm of membrane anatomy / 中华胃肠外科杂志

Anatomical plane and fascia have been described in medical behaviors for hundreds of years since the appearance of anatomy and operation. Generally, these descriptions can be sorted into three theories, i.e. plane surgery, fascia theory and mesentery anatomy. However, these theories are difficult to satisfy the scientific paradigm that includes consistency in description, independence in validation, potential to solve practical problems, and the interaction of the above-mentioned theries. Recently, membrane anatomy was proposed as the anatomy of mesentery and its beds in broad sense. Behind it lies fascia membrane/serous membrane structure, as well as inherent life events and general order. Mesentery in broad sense is described as the fascia membrane/serous membrane in serous cavity, which envelops and suspends the organ/tissue and its feeding structures to the posterior wall of the body. Anatomy is the setting/structure, in which life events/functions occur. In the research and discussion of membrane anatomy, abiding by the scientific paradigm and upholding the scientific spirit are the only way to obtain reliable knowledge and the criterion for in-depth scientific research.

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.