The mesenteric entry site as a potential weak point in gastrointestinal anastomoses - findings from an ex-vivo biomechanical analysis.

PURPOSE: Gastrointestinal disorders frequently necessitate surgery involving intestinal resection and anastomosis formation, potentially leading to severe complications like anastomotic leakage (AL) which is associated with increased morbidity, mortality, and adverse oncologic outcomes. While extensive research has explored the biology of anastomotic healing, there is limited understanding of the biomechanical properties of gastrointestinal anastomoses, which was aimed to be unraveled in this study. METHODS: An ex-vivo model was developed for the biomechanical analysis of 32 handsewn porcine end-to-end anastomoses, using interrupted and continuous suture techniques subjected to different flow models. While multiple cameras captured different angles of the anastomosis, comprehensive data recording of pressure, time, and temperature was performed simultaneously. Special focus was laid on monitoring time, location and pressure of anastomotic leakage (LP) and bursting pressures (BP) depending on suture techniques and flow models. RESULTS: Significant differences in LP, BP, and time intervals were observed based on the flow model but not on the suture techniques applied. Interestingly, anastomoses at the insertion site of the mesentery exhibited significantly higher rates of leakage and bursting compared to other sections of the anastomosis. CONCLUSION: The developed ex-vivo model facilitated comparable, reproducible, and user-independent biomechanical analyses. Assessing biomechanical properties of anastomoses offers an advantage in identifying technical weak points to refine surgical techniques, potentially reducing complications like AL. The results indicate that mesenteric insertion serves as a potential weak spot for AL, warranting further investigations and refinements in surgical techniques to optimize outcomes in this critical area of anastomotic procedures.

[A Case of Intestinal Obstruction Due to an Internal Hernia in the Mesenteric Defect after Laparoscopic Resection of Transverse Colon].

72-year-old man who was diagnosed with transverse colon cancer cT3N1aM0, Stage Ⅲb, and underwent laparoscopic- assisted resection of the transverse colon. Postoperatively, the patient was discharged from the hospital after 24 days due to complications such as paralytic ileus and intra-abdominal abscess caused by prolonged intestinal congestion. On postoperative day 91, the patient developed abdominal pain and vomiting at home, and was rushed to our hospital on the same day. Abdominal CT showed that an internal hernia had formed in the mesenteric defect after resection of the transverse colon, which was suspected to have caused obstruction of the small intestine. After adequate preoperative decompression of the intestinal tract, a laparoscopic surgery was performed on the 9th day. The operative findings were that the jejunum(100- 160 cm from the Treitz ligament)had strayed into the mesenteric defect of the transverse colon, resulting in an internal hernia. After the internal hernia was repaired laparoscopically, the mesenteric defect was closed with a 3-0 V-Loc(non- absorbable). The patient had a good postoperative course and was discharged home 6 days after surgery.

[A Case of Desmoid-Type Fibromatosis of the Mesentery of Small Intestine].

Desmoid-type fibromatosis is a relatively rare disease, often associated with familial adenomatous polyposis and a history of abdominal surgery. A 43-year-old male patient presented with abdominal pain and contrast-enhanced CT showed a mass in the lower abdomen. The mass was a 4×4×3 cm white, dense tumor with a wreath-like arrangement of eosinophilic spindle-shaped cells. Immunostaining showed KIT(-), CD34(-), desmin(-), ß-catenin(+), SMA(few+), and the diagnosis was desmoid-type fibrosis. Six months after surgery, there was no apparent recurrence.

Recurrent mucinous cystic neoplasm of the mesentery in a young nullipara mimicking as ovarian carcinoma.

INRODUCTION: Mucinous cystic neoplasms are rare tumors. They may originate from either ovaries, pancreas, or other intra-abdominal sites, but rarely from the mesentery. CASE HISTORY: A 22-year-old nulliparaous woman, who had undergone laparascopic bilateral cystectomy for recurrent ovarian mass, presented with pain in abdomen, backache, and menstrual irregularities. Provisionally diagnosed as ovarian carcinoma, she underwent bilateral salpingo-oophorectomy and sigmoid colectomy. However, the histopathological examination revealed mucinous cystic neoplasm of the mesentery. DISCUSSION: Thus, complete resection of the cysts with meticulous gross and histopathological examination remains the gold standard to differentiate mucinous cystic neoplasm (MCN) of the mesentery from its mimics, especially malignant counterparts, enabling clinicians to adequately manage such patients. Here, we present a case of recurrent MCN of mesentery (mesocolon), mimicking as ovarian carcinoma confirmed on histopathological examination, in a young adult.

A case of seatbelt-induced mesenteric injury and delayed colon ischemia after a car accident.

Trauma is the sixth leading cause of death globally and the leading cause of morbidity and mortality in young patients. Blunt bowel and mesenteric injuries are rare, occuring in only 1-5% of blunt abdominal traumas, and are associated with high morbidity and mortality. In this report, we present a case of a patient with sigmoid colon perforation due to ischemia caused by mesenteric injury, who was admitted to the hospital with abdominal pain two days after a car accident. A twenty-one-year-old man was admitted to the emergency department with abdominal pain and vomiting, having been involved in a car accident as a driver two days prior. Computed tomogra-phy revealed free air in the abdomen, originating from the perforation of the sigmoid colon wall, and free fluid in the pelvic area. The patient underwent immediate laparotomy. Exploration revealed a rupture in the sigmoid mesocolon, causing ischemia and perforation. Additionally, there was a rupture in the mesentery of the terminal ileum close to the ileocecal valve, but without ischemia. Partial sig-moid colon and ileal resections were performed, followed by colocolic anastomosis and double-barrel ileostomy. He was discharged in good health after a 20-day hospital stay. Thorough clinical examination and radiological evaluation can aid in detecting visceral injuries in trauma patients. Early recognition and repair of intestinal damage can prevent severe complications.

Peritonectomy and resection of mesentery during Visceral-Peritoneal Debulking (VPD) in patients with stage IIIC-IV ovarian cancer: A phase I-II trial.

OBJECTIVE: To describe the surgical technique, assess feasibility, efficacy, and safety of peritonectomy and/or resection of mesentery (P-Rme) during Visceral-Peritoneal Debulking (VPD) in patients with stage IIIC-IV ovarian cancer (OC). METHODS: In April 2009 we registered a protocol study on the safety and feasibility of P-Rme. In the period April 2009-December 2022, 687 patients with FIGO stage IIIC-IV ovarian cancer underwent VPD. One hundred and twenty-nine patients (18.7%) had extensive disease on the mesentery and underwent P-Rme. Feasibility was assessed as the number of procedures completed. Efficacy was measured as the rate of Complete Resection (CR). Safety was defined by the intra- and post-operative morbidity rate specifically associated with these procedures. RESULTS: In all patients P-Rme was successfully completed. P-me was performed in 82 patients and R-me in 47, both procedures in 23 patients. CR was achieved in all 129 patients with an efficacy of 100%. Intra-operatively 5 patients out of 129 experienced small bowel loop surgical devascularization. They required small bowel resection and anastomosis. The procedure specific morbidity was 3.8%. No post-operative complication was related to P-Rme. At 64 months median follow-up, survival outcomes in the study group were similar to patients in the control group. CONCLUSION: Overall, almost 20% of the VPD patients needed P-Rme to obtain a CR. P-Rme was a safe and effective step during VPD. The rate of CR in the study group was 100% achieved thanks to the addition of the P-Rme. No procedure specific post-operative complications occurred but 3.8% of the patients had unplanned additional surgery related to these procedures.

Comparison between the mesenteric fixation method (MEFIX) and conventional methods at preventing the occurrence of Petersen's hernia: a study protocol for a multicenter randomized controlled trial.

BACKGROUND: Petersen's hernia, which occurs after Billroth-II (B-II) or Roux-en-Y (REY) anastomosis, can be reduced by defect closure. This study aims to compare the incidence of bowel obstruction above Clavien-Dindo classification grade III due to Petersen's hernia between the mesenteric fixation method and the conventional methods after laparoscopic or robotic gastrectomy. METHODS: This study was designed as prospective, single-blind, non-inferiority randomized controlled multicenter trial in Korea. Patients with histologically diagnosed gastric cancer of clinical stages I, II, or III who underwent B-II or REY anastomosis after laparoscopic or robotic gastrectomy are enrolled in this study. Participants who meet the inclusion criteria are randomly assigned to two groups: a CLOSURE group that underwent conventional Petersen's defect closure method and a MEFIX group that underwent the mesenteric fixation method. The primary endpoint is the number of patients who underwent surgery for bowel obstruction caused by Petersen's hernia within 3 years after laparoscopic or robotic gastrectomy. DISCUSSION: This trial is expected to provide high-level evidence showing that the MEFIX method can quickly and easily close Petersen's defect without increased postoperative complications compared to the conventional method. TRIAL REGISTRATION: ClinicalTrials.gov NCT05105360. Registered on November 3, 2021.

Safety & feasibility of targeted mesenteric approaches with Kono-S anastomosis and extended mesenteric excision in ileocolic resection and anastomosis in Crohn's disease.

BACKGROUND: The mesentery has recently been implicated in the pathophysiology of Crohn's disease (CD), and several techniques have been developed to target the mesentery to reduce its influence on recurrence. We aimed to describe short-term safety and feasibility after these approaches. METHODS: This is a comparative, retrospective, single-center cohort study of consecutive CD patients undergoing primary or redo ileocolic resection from 2015 to 2022 with Kono-S anastomosis (KSA), extended mesenteric excision (EME) only, or both: mesenteric excision and exclusion (MEE). RESULTS: 186 patients underwent KSA (n â€‹= â€‹74), EME (n â€‹= â€‹66), or MEE (n â€‹= â€‹46). The groups had comparable baseline characteristics. The MEE group operative time was longer (median: 187 vs. KSA 170, EME 152 â€‹min, p â€‹< â€‹0.01). Postoperatively, the groups had similar lengths of stay (median 4 days), readmissions (9.1 â€‹%), major postoperative complications (6.5 â€‹%), and anastomotic leaks (1.1 â€‹%). CONCLUSION: Targeting the mesentery with novel surgical approaches for ileocolic Crohn's disease was safe and feasible for short-term follow-up.

[A Case of Desmoid Fibromatosis of the Small Intestinal Mesentery Institutions].

The patient was a 27-year-old man. He was referred to our hospital because he was aware of a mass in his abdomen. An abdominal ultrasound showed a 70-mm mass lesion. Enhanced computed tomography showed a 70-mm mass with well- defined margins and heterogeneous internal enhancement near the proximal jejunum. The patient was diagnosed with a suspected primary submucosal tumor of the duodenum or small intestine, and surgery was planned to diagnose and treat the tumor. The tumor was located in the upper jejunal mesentery, and tumor resection and partial small bowel resection were performed. Histopathological examination revealed proliferation of spindle-shaped cells without karyomitosis, and mixed collagen fibers in the tissue. Immunohistochemistry showed ß-catenin(+), SMA(+), AE1/AE3(-), KIT(-), CD34(-), and S-100(-). Based on these findings, we diagnosed primary desmoid fibromatosis of the small intestinal mesentery. In this report, we describe a case of primary desmoid fibromatosis of the small intestinal mesentery with a review of the literature.

[Small bowel volvulus due to a giant mesenteric lipoma]. / Zavorot tonkoi kishki, obuslovlennyi gigantskoi lipomoi bryzheiki.

Mesenteric lipomas are very rare. They are asymptomatic in most cases, but some patients can develop certain complications such as small bowel volvulus and acute small bowel obstruction. We report a 78-year-old patient with giant mesenteric lipoma complicated by jejunum volvulus and acute small bowel obstruction. The patient underwent laparotomy, en-bloc resection of small bowel, mesentery and lipoma followed by side-to-side anastomosis.

[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.

[A decade's review for membrane anatomy: the setting,events in it, order formed by primary fascia and serous membrane].

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.

[Landmark vessel in membrane anatomy-based colorectal surgery].

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.

[Development of membrane anatomy theory in gastric cancer surgery].

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).

[Application of membrane anatomy in hepatopancreatobiliary and splenic surgery].

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.