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Taiwanese Journal of Obstetrics &... Dec 2009Since the initial description of laparoscopic myomectomy (LM) in 1979, many reports of this technique have been published worldwide. The indications for LM have grown in... (Review)
Review
Since the initial description of laparoscopic myomectomy (LM) in 1979, many reports of this technique have been published worldwide. The indications for LM have grown in line with improvements in laparoscopic techniques and instruments over the last decade. LM offers several benefits to patients but remains a challenging technical procedure that is associated with high surgical morbidity and a high incidence of blood transfusion. LM procedures include excision of the myoma(s), repair of myometrium, and removal of the myoma from the abdomen. The control of operative blood loss is crucial, especially in the case of large intramural fibroids. Different studies have found wide variations in the incidence of recurrence after LM. Ultrasound imaging and Doppler velocimetry can be used to assess uterine scars after LM. Uterine rupture during pregnancy is a serious concern after LM, and all published cases report the occurrence of rupture before the start of labor. Surgical strategies are needed to overcome these problems associated with LM. Although LM is minimally invasive in terms of the wound, it remains an advanced and invasive procedure. An appropriate management strategy is required for each patient, and careful discussion and counseling regarding all the issues are necessary.
Topics: Female; Humans; Laparoscopy; Leiomyoma; Myometrium; Uterine Neoplasms
PubMed: 20045753
DOI: 10.1016/S1028-4559(09)60321-1 -
Experimental Physiology Mar 2014In this short review, we discuss how recent insights into myometrial physiology may be taken forward and translated into much-needed novel therapies for problems... (Review)
Review
In this short review, we discuss how recent insights into myometrial physiology may be taken forward and translated into much-needed novel therapies for problems associated with labour. We consider excitation-contraction coupling in the myometrium and how this relates to our understanding of the changes that occur to produce myometrial contractions and successful labour. We then discuss how this information has already been used in the development of drugs to either stimulate or relax the myometrium, to address the needs of women with either slow (dystocic) labours or threatened preterm labours, respectively. We next present the data showing how basic physiological findings pertaining to hypoxia and lactate production have been taken and translated into a tool for predicting and thus better managing difficult labours. We then highlight examples of where physiological research has started to provide mechanistic insight into clinical problems associated with labour and parturition (obesity, diabetes, advanced maternal age, postdate and twin pregnancies) and suggest how these findings could be translated into new therapies for difficult labours.
Topics: Adult; Diabetes, Gestational; Female; Humans; Maternal Age; Myometrium; Pregnancy; Signal Transduction; Translational Research, Biomedical; Uterine Contraction
PubMed: 24317408
DOI: 10.1113/expphysiol.2013.076216 -
Scientific Reports Nov 2022Pre-labour uterine contractions, occurring throughout pregnancy, are an important phenomenon involving the placenta in addition to the myometrium. They alter the uterine...
Pre-labour uterine contractions, occurring throughout pregnancy, are an important phenomenon involving the placenta in addition to the myometrium. They alter the uterine environment and thus potentially the blood supply to the fetus and may thus provide crucial insights into the processes of labour. Assessment in-vivo is however restricted due to their unpredictability and the inaccessible nature of the utero-placental compartment. While clinical cardiotocography (CTG) only allows global, pressure-based assessment, functional magnetic resonance imaging (MRI) provides an opportunity to study contractile activity and its effects on the placenta and the fetus in-vivo. This study aims to provide both descriptive and quantitative structural and functional MR assessments of pre-labour contractions in the human uterus. A total of 226 MRI scans (18-41 weeks gestation) from ongoing research studies were analysed, focusing on free-breathing dynamic quantitative whole uterus dynamic T2* maps. These provide an indirect measure of tissue properties such as oxygenation. 22 contractile events were noted visually and both descriptive and quantitative analysis of the myometrial and placental changes including volumetric and T2* variations were undertaken. Processing and analysis was successfully performed, qualitative analysis shows distinct and highly dynamic contraction related characteristics including; alterations in the thickness of the low T2* in the placental bed and other myometrial areas, high intensity vessel-like structures in the myometrium, low-intensity vessel structures within the placental parenchyma and close to the chorionic plate. Quantitative evaluation shows a significant negative correlation between T2* in both contractile and not-contractile regions with gestational age (p < 0.05) as well as a significant reduction in T2* during contractions. The T2* values in the myometrium were however not correlated to gestational age (p > 0.5). The quantitative and qualitative description of uterine pre-labour contractions including dynamic changes and key characteristics aims to contribute to the sparsely available in-vivo information and to provide an in-vivo tool to study this important phenomenon. Further work is required to analyse the origins of these subclinical contractions, their effects in high-risk pregnancies and their ability to determine the likelihood of a successful labour. Assessing T2* distribution as a marker for placental oxygenation could thus potentially complement clinically used cardiotocography measurements in the future.
Topics: Female; Pregnancy; Humans; Myometrium; Placenta; Uterine Contraction; Labor, Obstetric; Uterus
PubMed: 36329074
DOI: 10.1038/s41598-022-22008-3 -
International Journal of Environmental... Nov 2021Classically, the diagnosis of adenomyosis relied on histological examination of uteri following hysterectomy and classifications focused on the depth of endometrial... (Review)
Review
Classically, the diagnosis of adenomyosis relied on histological examination of uteri following hysterectomy and classifications focused on the depth of endometrial invasion within the myometrium. There remain uncertainties around the cut-off point for the histological diagnosis. Imaging-based diagnosis enables recognition of the condition in women not undergoing surgery and facilitates the assessment of the extent of adenomyosis within the whole uterus, as well as of affections of the uterovesical pouch and of the pouch of Douglas. In this article, we explore the diagnostic uncertainties, the need to produce a classification of the condition and the challenges towards that goal. A distinction should be drawn between disease mapping and a classification that may link histological or image-based features with clinical characteristics, or with pathophysiology. An agreed system for reporting adenomyotic lesions may enable comparisons of research studies and thus contribute towards an informed classification. To this aim, we outline the features of the condition and explore the characteristics that are considered when producing a taxonomy. These include the latest proposal for subdivision of adenomyosis into an internal and an external variant. We also explore the uncertainties linked to classifying involvement of the uterovesical pouch, the pouch of Douglas and lesions in the outer myometrium. The limitations of currently available evidence suggest that agreement on a hypothesis to underpin a classification is unlikely at present. Therefore, current efforts will probably remain focused on disease mapping.
Topics: Adenomyosis; Endometriosis; Endometrium; Female; Humans; Hysterectomy; Myometrium; Uterus
PubMed: 34886111
DOI: 10.3390/ijerph182312386 -
Trends in Endocrinology and Metabolism:... Jul 2018Progesterone acts through the progesterone receptor to direct physiological adaption of the uterus in preparation and completion of pregnancy. Genome-wide transcriptome... (Review)
Review
Progesterone acts through the progesterone receptor to direct physiological adaption of the uterus in preparation and completion of pregnancy. Genome-wide transcriptome and cistrome analyses have uncovered new members and novel modifiers of the progesterone signaling pathway. Genetically engineered mice allow functional assessment of newly identified genes in vivo and provide insights on the impact of progesterone receptor-dependent molecular mechanisms on pregnancy at the organ system level. Progesterone receptor isoforms collectively mediate progesterone signaling via their distinct and common downstream target genes, which makes the stoichiometry of isoforms relevant in modifying the progesterone activity. This review discusses recent advances on the discovery of the progesterone receptor network, with special focus on the endometrium at early pregnancy and myometrium during parturition.
Topics: Animals; Female; Humans; Myometrium; Parturition; Pregnancy; Receptors, Progesterone; Signal Transduction
PubMed: 29705365
DOI: 10.1016/j.tem.2018.04.001 -
Biology of Reproduction Dec 2014Tissue-specific (or somatic) stem cells constitute a subset of cells residing in normal adult tissues. By undergoing asymmetric division, they retain their ability to... (Review)
Review
Tissue-specific (or somatic) stem cells constitute a subset of cells residing in normal adult tissues. By undergoing asymmetric division, they retain their ability to self-renew while producing daughter cells that go on to differentiate and play a role in tissue regeneration and repair. The human uterus consists primarily of endometrium and myometrium (the smooth muscle layer) that rapidly enlarges through its tremendous regenerative and remodeling capacity to accommodate the developing fetus. Such uterine enlargement and remodeling can take place repeatedly and cyclically over the course of a woman's reproductive life. These unique properties of the uterus suggest the existence of endometrial and myometrial stem cell systems. In addition, like somatic cells, tumor stem cells or tumor-initiating cells, a subset of cells within a tumor, retain the ability to reconstitute tumors. Uterine smooth muscle cells are thought to be the origin of leiomyomas that are the most common type of gynecologic tumor. Recent work has identified, isolated, and characterized putative stem/progenitor cells in the myometrium and in leiomyomas. Here, we review current studies of myometrial and leiomyoma stem/progenitor cells and provide a new paradigm for understanding myometrial physiology and pathology and how these cells might contribute to uterine remodeling during pregnancy and the formation of leiomyomas. The role of the WNT/CTNNB1 pathway in the pathogenesis of leiomyoma is also discussed.
Topics: Adult; Animals; Disease Models, Animal; Female; Humans; Leiomyoma; Myometrium; Neoplastic Stem Cells; Organ Specificity; Pregnancy; Stem Cells; Uterine Neoplasms
PubMed: 25376230
DOI: 10.1095/biolreprod.114.123794 -
Experimental Biology and Medicine... May 2021The myometrium is the smooth muscle layer of the uterus that generates the contractions that drive processes such as menstruation and childbirth. Aberrant contractions... (Review)
Review
The myometrium is the smooth muscle layer of the uterus that generates the contractions that drive processes such as menstruation and childbirth. Aberrant contractions of the myometrium can result in preterm birth, insufficient progression of labor, or other difficulties that can lead to maternal or fetal complications or even death. To investigate the underlying mechanisms of these conditions, the most common model systems have conventionally been animal models and human tissue strips, which have limitations mostly related to relevance and scalability, respectively. Myometrial smooth muscle cells have also been isolated from patient biopsies and cultured as a more controlled experimental system. However, approaches have focused primarily on measuring the effects of biochemical stimuli and neglected biomechanical stimuli, despite the extensive evidence indicating that remodeling of tissue rigidity or excessive strain is associated with uterine disorders. In this review, we first describe the existing approaches for modeling human myometrium with animal models and human tissue strips and compare their advantages and disadvantages. Next, we introduce existing techniques and assays for assessing contractility and summarize their applications in elucidating the role of biochemical or biomechanical stimuli on human myometrium. Finally, we conclude by proposing the translation of "organ on chip" approaches to myometrial smooth muscle cells as new paradigms for establishing their fundamental mechanobiology and to serve as next-generation platforms for drug development.
Topics: Animals; Biophysical Phenomena; Female; Humans; In Vitro Techniques; Models, Animal; Models, Biological; Myocytes, Smooth Muscle; Myometrium
PubMed: 33554648
DOI: 10.1177/1535370221989259 -
Tissue Engineering. Part A Oct 2013Neo-myometrium was created by culturing isolated myocytes into decellularized rat and human myometrial scaffolds. The dual purpose of the uterus is to accommodate the...
Neo-myometrium was created by culturing isolated myocytes into decellularized rat and human myometrial scaffolds. The dual purpose of the uterus is to accommodate the growing fetus, and then expel the fetus at term by phasically contracting it. The first function requires physical robustness as well as the ability to expand and remodel. Congenital anomalies or previous surgeries can mechanically compromise the uterus and lead to major complications in pregnancy. The second function utilizes multiple interactions of complex physiological mechanisms that have yet to be fully elucidated, and this knowledge gap contributes to the continuation of serious complications of pregnancy. To address both problems, we reconstructed myometrium from isolated myocytes and scaffold. From both rat and human myometrium, myocytes were isolated using collagenase digestion, and scaffolds were isolated using ethanol/ trypsin protocols. The number of myocytes was amplified using monolayer culture, and then, the myocytes were cultured back into the scaffolds. We called this engineered tissue neo-myometrium, with allo-neo-myometrium being made from components of the same species, and xeno-neo-myometrium from across species. By artificially creating defects in rat scaffold, allo-neo-myometrium was created that demonstrated rapid scaffold remodeling. Xeno-neo myometrium (human myocytes/rat scaffold) was created and demonstrated myocytes occurring in bundles 500 μm deep in the scaffold. These experiments provide proof of principle that modest numbers of myocytes can be amplified and used to create a larger volume of engineered tissue, which may be useful for semi-autologous transplantation to repair structural defects of the human uterus. In isometric contractility experiments, coordinated contractions were observed in xeno-neo-myometrium (human myocytes, rat scaffold), but not allo-neo-myometrium (human myocytes, human scaffold).
Topics: Animals; Female; Humans; Muscle Cells; Myometrium; Pregnancy; Rats; Tissue Engineering; Tissue Scaffolds
PubMed: 23560472
DOI: 10.1089/ten.TEA.2012.0549 -
Women's Health (London, England) Aug 2015Several lines of recent evidence suggest that pelvic innervation is altered in endometriosis-affected women, and there is a strong presumption that nerve fibers... (Review)
Review
Several lines of recent evidence suggest that pelvic innervation is altered in endometriosis-affected women, and there is a strong presumption that nerve fibers demonstrated in eutopic endometrium (of women with endometriosis) and in endometriotic lesions play roles in the generation of chronic pelvic pain. The recent observation of sensory C, sensory A-delta, sympathetic and parasympathetic nerve fibers in the functional layer of endometrium of most women affected by endometriosis, but not demonstrated in most women who do not have endometriosis, was a surprise. Nerve fiber densities were also greatly increased in myometrium of women with endometriosis and in endometriotic lesions compared with normal peritoneum. Chronic pelvic pain is complex, and endometriosis is only one condition which contributes to this pain. The relationship between the presence of certain nerve fibers and the potential for local pain generation requires much future research. This paper reviews current knowledge concerning nerve fibers in endometrium, myometrium and endometriotic lesions, and discusses avenues of research that may improve our knowledge and lead to enriched understanding and management of endometriotic pain symptoms.
Topics: Adult; Endometriosis; Endometrium; Female; Humans; Myometrium; Nerve Fibers; Pelvic Pain; Women's Health
PubMed: 26314611
DOI: 10.2217/whe.15.47 -
Fertility and Sterility Mar 2023
Topics: Female; Humans; Adenomyosis; Ultrasonography; Myometrium
PubMed: 36621709
DOI: 10.1016/j.fertnstert.2022.12.043