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Emerging Topics in Life Sciences Sep 2020The mesentery is the organ in which all abdominal digestive organs develop, and which maintains these in systemic continuity in adulthood. Interest in the mesentery was... (Review)
Review
The mesentery is the organ in which all abdominal digestive organs develop, and which maintains these in systemic continuity in adulthood. Interest in the mesentery was rekindled by advancements of Heald and Hohenberger in colorectal surgery. Conventional descriptions hold there are multiple mesenteries centrally connected to the posterior midline. Recent advances first demonstrated that, distal to the duodenojejunal flexure, the mesentery is a continuous collection of tissues. This observation explained how the small and large intestines are centrally connected, and the anatomy of the associated peritoneal landscape. In turn it prompted recategorisation of the mesentery as an organ. Subsequent work demonstrated the mesentery remains continuous throughout development, and that abdominal digestive organs (i.e. liver, spleen, intestine and pancreas) develop either on, or in it. This relationship is retained into adulthood when abdominal digestive organs are directly connected to the mesentery (i.e. they are 'mesenteric' in embryological origin and anatomical position). Recognition of mesenteric continuity identified the mesenteric model of abdominal anatomy according to which all abdominal abdomino-pelvic organs are organised into either a mesenteric or a non-mesenteric domain. This model explains the positional anatomy of all abdominal digestive organs, and associated vasculature. Moreover, it explains the peritoneal landscape and enables differentiation of peritoneum from the mesentery. Increased scientific focus on the mesentery has identified multiple vital or specialised functions. These vary across time and in anatomical location. The following review demonstrates how recent advances related to the mesentery are re-orientating the study of human biology in general and, by extension, clinical practice.
Topics: Animals; Digestive System; Duodenum; Embryonic Development; Humans; Mesentery; Peritoneum; Tomography, X-Ray Computed
PubMed: 32539112
DOI: 10.1042/ETLS20200006 -
Communications Biology Aug 2021The position of abdominal organs, and mechanisms by which these are centrally connected, are currently described in peritoneal terms. As part of the peritoneal model of...
The position of abdominal organs, and mechanisms by which these are centrally connected, are currently described in peritoneal terms. As part of the peritoneal model of abdominal anatomy, there are multiple mesenteries. Recent findings point to an alternative model in which digestive organs are connected to a single mesentery. Given that direct evidence of this is currently lacking, we investigated the development and shape of the entire mesentery. Here we confirm that, within the abdomen, there is one mesentery in which all abdominal digestive organs develop and remain connected to. We show that all abdominopelvic organs are organised into two, discrete anatomical domains, the mesenteric and non-mesenteric domain. A similar organisation occurs across a range of animal species. The findings clarify the anatomical foundation of the abdomen; at the foundation level, the abdomen comprises a visceral (i.e. mesenteric) and somatic (i.e. musculoskeletal) frame. The organisation at that level is a fundamental order that explains the positional anatomy of all abdominopelvic organs, vasculature and peritoneum. Collectively, the findings provide a novel start point from which to systemically characterise the abdomen and its contents.
Topics: Humans; Mesentery; Peritoneum
PubMed: 34408242
DOI: 10.1038/s42003-021-02496-1 -
Clinical Obstetrics and Gynecology Jun 2020This chapter reviews issues which complicate surgery in obese pregnant patients. Maternal obesity is prevalent in the United States and is associated with numerous... (Review)
Review
This chapter reviews issues which complicate surgery in obese pregnant patients. Maternal obesity is prevalent in the United States and is associated with numerous adverse health outcomes. When surgery is indicated during pregnancy, the presence of maternal obesity increases surgical risks for both the fetus and mother. Specific risks are identified and strategies to avoid them are evaluated. The prognosis and management of pregnant women who have undergone bariatric surgery is also discussed, and practical guidelines for obstetric management of these patients are presented.
Topics: Abdominal Cavity; Bariatric Surgery; Comorbidity; Female; Humans; Obesity, Maternal; Postoperative Complications; Pregnancy; Pregnancy Complications; Risk Adjustment; Risk Assessment; Surgical Procedures, Operative
PubMed: 32224705
DOI: 10.1097/GRF.0000000000000530 -
Journal of Minimally Invasive Gynecology Mar 2021Entry into the abdomen during operative laparoscopy is a source of some controversy regarding the safest and most useful method. The objective of this review is to... (Review)
Review
OBJECTIVE
Entry into the abdomen during operative laparoscopy is a source of some controversy regarding the safest and most useful method. The objective of this review is to describe, compare, and contrast the most popular entry techniques.
DATA SOURCES
Data were collected from the historical starting point until present day from English language journal articles and book chapters.
METHODS OF STUDY SELECTION
Descriptive accounts dating back to the start of laparoscopy in the 1970s and spanning to present day well-designed randomized controlled trials and Cochrane reviews were compiled to evaluate the evidence for the effectiveness and safety of abdominal entry techniques.
TABULATION, INTEGRATION, AND RESULTS
The most common sites of entry are the umbilicus and the left upper quadrant. Between the Veress needle, direct trocar insertion, and open entry there is no high-quality evidence to suggest that any of these offers a universal safety advantage. The Veress needle is still the most used among gynecologists and facilitates primary trocar placement. Direct trocar entry under laparoscopic visualization may be underused, is faster, and may result in fewer failed entries. Open (Hasson) entry can be more technically challenging, but may be best for patients with suspected intra-abdominal adhesions.
CONCLUSION
Surgeon comfort is critical in choosing the entry site, method, and equipment. Surgeon familiarity with entry-failure troubleshooting, possible complications, and management is essential because major entry complications are rare in modern laparoscopy but critical because the essential steps of recognition and management can be lifesaving.
Topics: Abdomen; Abdominal Cavity; Female; Gynecologic Surgical Procedures; History, 20th Century; History, 21st Century; Humans; Laparoscopy; Needles; Postoperative Complications; Surgical Instruments; Umbilicus
PubMed: 32712324
DOI: 10.1016/j.jmig.2020.07.010 -
Biomolecules May 2021Post-surgical adhesions are internal scar tissue and a major health and economic burden. Adhesions affect and involve the peritoneal lining of the abdominal cavity,... (Review)
Review
Post-surgical adhesions are internal scar tissue and a major health and economic burden. Adhesions affect and involve the peritoneal lining of the abdominal cavity, which consists of a continuous mesothelial covering of the cavity wall and majority of internal organs. Our understanding of the full pathophysiology of adhesion formation is limited by the fact that the mechanisms regulating normal serosal repair and regeneration of the mesothelial layer are still being elucidated. Emerging evidence suggests that mesothelial cells do not simply form a passive barrier but perform a wide range of important regulatory functions including maintaining a healthy peritoneal homeostasis as well as orchestrating events leading to normal repair or pathological outcomes following injury. Here, we summarise recent advances in our understanding of serosal repair and adhesion formation with an emphasis on molecular mechanisms and novel gene expression signatures associated with these processes. We discuss changes in mesothelial biomolecular marker expression during peritoneal development, which may help, in part, to explain findings in adults from lineage tracing studies using experimental adhesion models. Lastly, we highlight examples of where local tissue specialisation may determine a particular response of peritoneal cells to injury.
Topics: Gene Expression Regulation, Developmental; Gene Regulatory Networks; Genetic Markers; Humans; Peritoneum; Tissue Adhesions
PubMed: 34063089
DOI: 10.3390/biom11050692 -
Radiographics : a Review Publication of... 2020Intra-abdominal calcifications are common. Multiple pathologic processes manifest within the abdomen and pelvis in association with calcifications, which can be benign,... (Review)
Review
Intra-abdominal calcifications are common. Multiple pathologic processes manifest within the abdomen and pelvis in association with calcifications, which can be benign, premalignant, or malignant. Although calcium deposition in the abdomen can occur secondary to various mechanisms, the most common cau se is cellular injury that leads to dystrophic calcifications. The authors provide a summary of various common and uncommon calcifications in the abdomen and pelvis, primarily using location to illuminate diagnostic significance. Six broad categories of calcifications in the abdomen and pelvis are recognized: mesenteric, peritoneal, retroperitoneal, organ-based, vascular, and musculoskeletal. In addition to site, the various patterns and morphology of calcifications encountered in various conditions can be helpful for diagnosis, especially those depicted on radiographs. For example, some patterns diagnostic for various conditions include round or oval stones in the biliary or urothelial tracts, curvilinear calcifications associated with cysts or neoplasms, and sheetlike calcifications along peritoneal surfaces in the setting of chronic peritoneal dialysis or metastatic disease. Organ encrustation with calcium may be a premalignant finding (eg, porcelain gallbladder). In addition, the development of calcium after initiation of treatment can be used as an indicator of response in conditions such as tuberculosis, lymphoma, and hydatid disease. As calcifications are almost invariably detected at imaging, it is imperative for radiologists to be aware of their diagnostic implications and use the presence of calcification in an organ, mass, or other anatomic location for problem solving. RSNA, 2020.
Topics: Abdominal Cavity; Abdominal Neoplasms; Calcinosis; Diagnosis, Differential; Humans; Pelvis
PubMed: 32302263
DOI: 10.1148/rg.2020190152 -
Clinical Anatomy (New York, N.Y.) May 2022The precaecocolic fascia, previously known as Jackson's membrane, is a variable vascular peritoneal fold between the ascending colon and the right posterolateral...
The precaecocolic fascia, previously known as Jackson's membrane, is a variable vascular peritoneal fold between the ascending colon and the right posterolateral abdominal wall. First described in 1913, it was originally thought to be of developmental or inflammatory origin and associated with abdominal pain. This investigation aimed to review its frequency, form and structure and look for evidence of association with malformation of the bowel, or previous inflammation. 26 dissecting room cadavers were studied to identify the precaecocolic fascia, any malrotation of the colon or signs of previous inflammation: adhesions, surgical scars, or absence of the appendix. Its structure was examined histologically and latex injections were used to trace the arteries. Membranes comparable with previous descriptions of the precaecocolic fascia occurred in 12 of 26 abdomens. They varied in form and size from long and translucent to short, thick, and opaque. In structure, the fascia resembled a fold of peritoneum containing a thickened fibrous lamina. Large thin-walled arteries in the fascia crossed the arteries in the wall of the colon at the point of attachment. No significant association with colonic malrotation or markers of previous inflammation were found. Attention should be paid to the definition of the precaecocolic fascia and "membrane" seems a more appropriate term than "fascia". It is one of a recognized group of peritoneal folds/bands, doubtful in origin but unlikely to be post-inflammatory. It may modify colonic mobility or complicate colonic operations.
Topics: Colon; Colon, Ascending; Fascia; Humans; Inflammation; Peritoneum
PubMed: 34535937
DOI: 10.1002/ca.23787 -
The Lancet. Gastroenterology &... Jan 2022Over the past 5 years, systematic investigation of the mesenteric organ has expanded and shown that the mesentery is the organ in and on which all abdominal digestive... (Review)
Review
Over the past 5 years, systematic investigation of the mesenteric organ has expanded and shown that the mesentery is the organ in and on which all abdominal digestive organs develop and remain connected to. In turn, this observation has clarified the anatomical foundation of the abdomen and the fundamental order at that level. Findings related to the shape and development of the mesentery have illuminated its function, advancing our understanding of the pathobiology, diagnosis, and treatment of several abdominal and systemic diseases. Inclusion of the mesentery in surgical resections alters the course of benign and malignant diseases. Mesenteric-based scoring systems can enhance the radiological interpretation of abdominal disease. Emerging findings reconcile observations across scientific and clinical fields and have been assimilated into reference curricula and practice guidelines. This Review summarises the developmental, anatomical, and clinical advances made since the mesentery was redesignated as an organ in 2016.
Topics: Gastrointestinal Diseases; Gastrointestinal Tract; Humans; Lymphatic Metastasis; Mesentery
PubMed: 34822760
DOI: 10.1016/S2468-1253(21)00179-5 -
American Journal of Surgery Jun 2022
Topics: Abdomen; Abdominal Cavity; Chest Pain; Humans
PubMed: 34809909
DOI: 10.1016/j.amjsurg.2021.11.009 -
Radiographics : a Review Publication of... 2020Venous thromboembolism (VTE), which includes deep venous thrombosis and pulmonary embolism, is a significant cause of morbidity and mortality. In recent decades, US, CT,... (Review)
Review
Venous thromboembolism (VTE), which includes deep venous thrombosis and pulmonary embolism, is a significant cause of morbidity and mortality. In recent decades, US, CT, and MRI have surpassed catheter-based angiography as the imaging examinations of choice for evaluation of vascular structures and identification of thrombus owing to their ready availability, noninvasive nature, and, in the cases of US and MRI, lack of exposure to ionizing radiation. As a result, VTE and associated complications are commonly identified in day-to-day radiologic practice across a variety of clinical settings. A wide range of hereditary and acquired conditions can increase the risk for development of venous thrombosis, and many patients with these conditions may undergo imaging for unrelated reasons, leading to the incidental detection of VTE or one of the associated complications. Although the development of VTE may be an isolated occurrence, the imaging findings, in conjunction with the clinical history and vascular risk factors, may indicate a predisposing condition or underlying diagnosis. Furthermore, awareness of the many clinical conditions that result in an increased risk of venous thrombosis may aid in detection of thrombus and any concomitant complications. For these reasons, it is important that practicing radiologists be familiar with the multimodality imaging findings of thrombosis, understand the spectrum of diseases that contribute to the development of thrombosis, and recognize the potential complications of hypercoagulable states and venous thrombosis. RSNA, 2020.
Topics: Abdominal Cavity; Humans; Pelvis; Thrombophilia; Venous Thrombosis
PubMed: 32330086
DOI: 10.1148/rg.2020190097