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Seminars in Cell & Developmental Biology Aug 2019The peritoneum is a large serous membrane with both epithelial and mesenchymal features, and is essential for maintaining an intra-abdominal homeostatic equilibrium. The... (Review)
Review
The peritoneum is a large serous membrane with both epithelial and mesenchymal features, and is essential for maintaining an intra-abdominal homeostatic equilibrium. The peritoneum plays a central role in the pathogenesis of a number of disorders. Pathological processes affecting the peritoneum such as inflammation and carcinomatosis can have serious clinical consequences, but the pathophysiology of these conditions is poorly understood. Understanding peritoneal embryology, anatomy and physiology is crucial to comprehend pathophysiological mechanisms and to devise a new focus for research. The vascular response to pathological processes appears to be of considerable importance, since the peritoneal vasculature plays a pivotal role in most associated diseases. Therefore, this review summarizes currently available literature with special emphasis on the development, anatomy and function of the peritoneal vasculature. Pathological processes are described to illustrate physiological and pathophysiological characteristics of the peritoneum.
Topics: Humans; Peritoneum
PubMed: 30253239
DOI: 10.1016/j.semcdb.2018.09.007 -
Biomolecules Dec 2021Formation of peritoneal adhesions (PA) is one of the major complications following intra-abdominal surgery. It is primarily caused by activation of the mesothelial layer... (Review)
Review
Formation of peritoneal adhesions (PA) is one of the major complications following intra-abdominal surgery. It is primarily caused by activation of the mesothelial layer and underlying tissues in the peritoneal membrane resulting in the transition of mesothelial cells (MCs) and fibroblasts to a pro-fibrotic phenotype. Pro-fibrotic transition of MCs-mesothelial-to-mesenchymal transition (MMT), and fibroblasts activation to myofibroblasts are interconnected to changes in cellular metabolism and culminate in the deposition of extracellular matrix (ECM) in the form of fibrotic tissue between injured sides in the abdominal cavity. However, ECM is not only a mechanical scaffold of the newly synthetized tissue but reciprocally affects fibrosis development. Hyaluronan (HA), an important component of ECM, is a non-sulfated glycosaminoglycan consisting of N-acetyl-D-glucosamine (GlcNAc) and D-glucuronic acid (GlcUA) that can affect the majority of processes involved in PA formation. This review considers the role of endogenously produced HA in the context of different fibrosis-related pathologies and its overlap in the development of PA.
Topics: Epithelium; Fibroblasts; Hyaluronic Acid; Myofibroblasts; Peritoneum
PubMed: 35053193
DOI: 10.3390/biom12010045 -
Clinical and Experimental Immunology Dec 2023Peritonitis and the resulting peritoneal injuries are common problems that prevent long-term peritoneal dialysis (PD) therapy in patients with end-stage kidney diseases....
Peritonitis and the resulting peritoneal injuries are common problems that prevent long-term peritoneal dialysis (PD) therapy in patients with end-stage kidney diseases. Previously, we have analyzed the relationship between the complement system and progression of peritoneal injuries associated with PD, particularly focusing on the early activation pathways and effects of the anaphylatoxins. We here utilized a novel mAb 2H2 that blocks assembly of the membrane attack complex (MAC) to investigate roles of the complement terminal pathway in PD-associated peritoneal injury. We intraperitoneally injected mAb 2H2 anti-C5b-7 (2.5 or 5 mg/rat) once or twice over the five-day course of the experiment to investigate the effects of inhibiting formation of MAC in a fungal rat peritonitis model caused by repeated intraperitoneal administration of zymosan after methylglyoxal pretreatment (Zy/MGO model). Rats were sacrificed on day 5 and macroscopic changes in both parietal and visceral peritoneum evaluated. Peritoneal thickness, the abundance of fibrinogen and complement C3 and MAC deposition in tissue and accumulation of inflammatory cells were pathologically assessed. The results showed that mAb 2H2, but not isotype control mAb, reduced peritoneal thickness and accumulation of inflammatory cells in a dose and frequency-dependent manner in the Zy/MGO model. These effects were accompanied by decreased C3, MAC, and fibrinogen deposition in peritoneum. In conclusion, in the rat Zy/MGO model, complement terminal pathway activation and MAC formation substantially contributed to development of peritoneal injuries, suggesting that MAC-targeted therapies might be effective in preventing development of peritoneal injuries in humans.
Topics: Humans; Rats; Animals; Peritoneum; Magnesium Oxide; Rats, Sprague-Dawley; Peritonitis; Complement Activation; Complement Membrane Attack Complex; Fibrinogen
PubMed: 37549240
DOI: 10.1093/cei/uxad088 -
Seminars in Nuclear Medicine Sep 2020The peritoneum is the largest and most complex serous membrane in the human body. The peritoneal membrane is composed of a layer of mesothelium supported by a thin layer... (Review)
Review
The peritoneum is the largest and most complex serous membrane in the human body. The peritoneal membrane is composed of a layer of mesothelium supported by a thin layer of connective tissue. The peritoneum is one continuous sheet, forming two layers and a potential space between them - the peritoneal cavity- which is subdivided into multiple communicating spaces containing small amount of serous fluid that facilitates frictionless movement of mobile intraabdominal viscera. Peritoneum also contributes to fluid exchange mechanism and plays a role in immune response. The peritoneum is subject to many neoplastic and non-neoplastic processes including infections, trauma, developmental and inflammatory processes. Different Nuclear Medicine imaging techniques can be used to diagnose peritoneal diseases, most of these techniques can be customized depending on the clinical scenario and expected findings. Peritoneal scintigraphy can detect abnormal peritoneal communication or compartmentalization. Several nuclear medicine techniques can help characterize intraperitoneal fluid collections and differentiate sterile from infected fluid. PET imaging plays an important role in imaging of different neoplastic and non-neoplastic peritoneal pathologies. Nuclear radiologists need to be familiar with peritoneal anatomy and pathology to interpret peritoneal findings in dedicated peritoneal nuclear medicine imaging studies, as part of more general nuclear medicine scans, or on CT or MRI component of hybrid imaging studies. The purpose of this article is to review the normal peritoneal anatomy, various pathologic processes involving the peritoneum, and different nuclear medicine and hybrid imaging techniques that can help detect, characterize, and follow up peritoneal pathology.
Topics: Humans; Nuclear Medicine; Peritoneum
PubMed: 32768005
DOI: 10.1053/j.semnuclmed.2020.04.005 -
The Journal of Maternal-fetal &... Dec 2023To demonstrate the surgical and morbidity differences between upper and lower parametrial placenta invasion (PPI).
OBJECTIVE
To demonstrate the surgical and morbidity differences between upper and lower parametrial placenta invasion (PPI).
MATERIALS AND METHODS
Forty patients with placenta accreta spectrum (PAS) into the parametrium underwent surgery between 2015 and 2020. Based on the peritoneal reflection, the study compared two types of parametrial placental invasion (PPI), upper or lower. Surgical approach to PAS follows a conservative-resective method. Before delivery, surgical staging by pelvic fascia dissection established a final diagnosis of placental invasion. In upper PPI cases, the team attempted to repair the uterus after resecting all invaded tissues or performing a hysterectomy. In cases of lower PPI, experts performed a hysterectomy in all cases. The team only used proximal vascular (aortic occlusion) control in cases of lower PPI. Surgical dissection for lower PPI started finding the ureter in the pararectal space, ligating all the tissues (placenta and newly formed vessels) to create a tunnel to release the ureter from the placenta and placenta suppletory vessels. Overall, at least three pieces of the invaded area were sent for histological analysis.
RESULTS
Forty patients with PPI were included, 13 in the upper parametrium and 27 in the lower parametrium. MRI indicated PPI in 33/40 patients; in three, the diagnosis was presumed by ultrasound or medical background. The intrasurgical staging categorizes 13 cases of PPI performed and finds diagnosis in seven undetected cases. The expertise team completed a total hysterectomy in 2/13 upper PPI cases and all lower PPI cases (27/27). Hysterectomies in the upper PPI group were performed by extensive damage of the lateral uterine wall or with a tube compromise. Ureteral injury ensued in six cases, corresponding to cases without catheterization or incomplete ureteral identification. All aortic vascular proximal control (aortic balloon, internal aortic compression, or aortic loop) was efficient for controlling bleeding; in contrast, ligature of the internal iliac artery resulted in a useless procedure, resulting in uncontrollable bleeding and maternal death (2/27). All patients had antecedents of placental removal, abortion, curettage after a cesarean section, or repeated D&C.
CONCLUSIONS
Lower PAS parametrial involvement is uncommon but associated with elevated maternal morbidity. Upper and lower PPI has different surgical risks and technical approaches; consequently, an accurate diagnosis is needed. The clinical background of manual placental removal, abortion, and curettage after a cesarean or repeated D&C could be ideally studied to diagnose a possible PPI. For patients with high-risk antecedents or unsure ultrasound, a T2 weight MRI is always recommended. Performing comprehensive surgical staging in PAS allows the efficient diagnosis of PPI before using some procedures.
Topics: Pregnancy; Humans; Female; Placenta Accreta; Cesarean Section; Peritoneum; Placenta; Hysterectomy; Retrospective Studies; Morbidity
PubMed: 36966802
DOI: 10.1080/14767058.2023.2183764 -
Journal of Gynecology Obstetrics and... Sep 2021Lateral parametrium endometriosis (LPE) can be associated with infiltration of ureters and hypogastric plexus, causing severe painful symptoms and functional impairment,...
OBJECTIVE
Lateral parametrium endometriosis (LPE) can be associated with infiltration of ureters and hypogastric plexus, causing severe painful symptoms and functional impairment, and requiring complex and extensive surgery. The aim of this study was to evaluate the presentation of LPE lesions at transvaginal ultrasound, identifying sonographic features for disease recognition and mapping.
METHODS
This was a retrospective case-series of women with sonographic suspect of LPE confirmed at surgical exploration. We carried out a descriptive analysis of the ultrasound patterns of presentation and compared the features of the lesions according to their location cranially or caudally to the uterine artery.
RESULTS
Our population included 23 women, with a total of 26 parametrial lesions: all of them were hypoechoic, with absence of vascularization. Lesions lying above the uterine artery presented more frequently as ill-defined nodules (78.6 %, p < 0.01) and were associated with ipsilateral reduced or absent ovarian mobility (92.9 %, p < 0.01); the ones located below the uterine artery appeared more frequently as fan-shaped lesions with retraction of the surrounding tissues (83.3 %). Ureteral involvement was observed at surgery in 43.5 % of cases. In all patients, deep infiltrating endometriosis of the posterior compartment was observed: the utero-sacral ligaments were the most common location affected concurrently.
CONCLUSIONS
LPE may present at transvaginal sonography as hypoechoic, not vascularized lesions, most frequently with a nodular or with a fan-shaped appearance, respectively cranially or caudally to the uterine artery. Reduced ovarian sliding and ureteral involvement are commonly associated.
Topics: Adult; Endometriosis; Female; Humans; Italy; Peritoneum; Retrospective Studies; Statistics, Nonparametric; Ultrasonography
PubMed: 33737251
DOI: 10.1016/j.jogoh.2021.102116 -
Clinical Radiology Nov 2017Radiology reports of diffuse peritoneal disease should address key findings pertinent to the management of these patients. The reporting of radiology findings in... (Review)
Review
Radiology reports of diffuse peritoneal disease should address key findings pertinent to the management of these patients. The reporting of radiology findings in patients with peritoneal malignancy is currently variable and poorly standardised. Using the acronym "PAUSE" we emphasise the key imaging features that a radiology report should include in a patient with peritoneal malignancy, focussing on the key elements determining feasibility and likely prognosis of surgery and potential benefits from cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The term "PAUSE" incorporates the following: P, primary tumour and peritoneal carcinomatosis index (PCI) as estimated by imaging; A, ascites and abdominal wall involvement; U, unfavourable sites of involvement; S, small bowel and mesenteric disease; E, extra peritoneal metastases. Thus, "PAUSE" has the potential to standardise radiology reporting in this field.
Topics: Abdominal Wall; Ascites; Diagnostic Imaging; Humans; Intestine, Small; Mesentery; Peritoneal Neoplasms; Peritoneum; Severity of Illness Index
PubMed: 28778454
DOI: 10.1016/j.crad.2017.07.005 -
Journal of Immunology (Baltimore, Md. :... Aug 2022The local microenvironment shapes macrophage differentiation in each tissue. We hypothesized that in the peritoneum, local factors in addition to retinoic acid can...
The local microenvironment shapes macrophage differentiation in each tissue. We hypothesized that in the peritoneum, local factors in addition to retinoic acid can support GATA6-driven differentiation and function of peritoneal large cavity macrophages (LCMs). We found that soluble proteins produced by mesothelial cells lining the peritoneal cavity maintained GATA6 expression in cultured LCMs. Analysis of global gene expression of isolated mesothelial cells highlighted mesothelin (Msln) and its binding partner mucin 16 (Muc16) as candidate secreted ligands that potentially regulate GATA6 expression in peritoneal LCMs. Mice deficient for either of these molecules showed diminished GATA6 expression in peritoneal and pleural LCMs that was most prominent in aged mice. The more robust phenotype in older mice suggested that monocyte-derived macrophages were the target of Msln and Muc16. Cell transfer and bone marrow chimera experiments supported this hypothesis. We found that lethally irradiated Msln-/- and Muc16-/- mice reconstituted with wild-type bone marrow had lower levels of GATA6 expression in peritoneal and pleural LCMs. Similarly, during the resolution of zymosan-induced inflammation, repopulated peritoneal LCMs lacking expression of Msln or Muc16 expressed diminished GATA6. These data support a role for mesothelial cell-produced Msln and Muc16 in local macrophage differentiation within large cavity spaces such as the peritoneum. The effect appears to be most prominent on monocyte-derived macrophages that enter into this location as the host ages and also in response to infection.
Topics: Mice; Animals; Macrophages; Macrophages, Peritoneal; Peritoneal Cavity; Peritoneum; Epithelium
PubMed: 35868637
DOI: 10.4049/jimmunol.2200278 -
The British Journal of Radiology Mar 2021Pathologic involvement of the peritoneum can result from a wide variety of conditions, including both neoplastic and non-neoplastic entities. Neoplastic involvement of... (Review)
Review
Pathologic involvement of the peritoneum can result from a wide variety of conditions, including both neoplastic and non-neoplastic entities. Neoplastic involvement of the peritoneal ligaments, mesenteries, and spaces from malignant spread of epithelial cancers, termed peritoneal carcinomatosis, is frequently encountered at CT evaluation. However, a host of other more unusual benign and malignant neoplasms can manifest with peritoneal disease, including both primary and secondary peritoneal processes, many of which can closely mimic peritoneal carcinomatosis at CT. In this review, we discuss a wide array of unusual peritoneal-based neoplasms that can resemble the more common peritoneal carcinomatosis. Beyond reviewing the salient features for each of these entities, particular emphasis is placed on any specific clinical and CT imaging clues that may allow the interpreting radiologist to appropriately narrow the differential diagnosis and, in some cases, make an imaging-specific diagnosis.
Topics: Diagnosis, Differential; Humans; Peritoneal Neoplasms; Peritoneum; Tomography, X-Ray Computed
PubMed: 33353398
DOI: 10.1259/bjr.20201288 -
The British Journal of Surgery May 2023
Topics: Humans; Peritoneal Neoplasms; Peritoneum; Colorectal Neoplasms; Cytoreduction Surgical Procedures; Hyperthermia, Induced; Antineoplastic Combined Chemotherapy Protocols; Combined Modality Therapy
PubMed: 36884312
DOI: 10.1093/bjs/znad061