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International Journal of General... 2022Situs inversus totalis is a rare congenital abnormality characterized by a mirror-image transposition of both the abdominal and the thoracic organs. While this anomaly... (Review)
Review
Situs inversus totalis is a rare congenital abnormality characterized by a mirror-image transposition of both the abdominal and the thoracic organs. While this anomaly is known since the ancient times, practicing doctors do not have much experience with it. Laterality is established early in development, and any failure in that process might lead to a wide variety of disorders which may be partial or complete. describes the normal anatomy, is the complete reversal, and is used for any other abnormality of left-right development. Sidedness is regulated by genes: over 100 genes have been linked to laterality defects. Frequency of situs inversus is 1:10,000 and is more frequent in males: 1.5:1. Advanced imaging modalities can be used to assess fine anatomical details, which play a crucial role in these cases to plan radiologic or surgical interventions. Percutaneous biliary procedures, portal vein embolization are really challenging procedures in SIT patients due to the mirror effect. As most surgeons are right-handed, SIT operations can cause difficulties: handling the instruments with their left hand or the pedals with their left foot can be uncomfortable Organ, especially liver transplantation represents an extraordinary surgical challenge. Solutions to overcome the anatomic differences include the use of segment or reduced size graft with rotation, modified piggy-back technique, side to-side caval anastomosis, and vascular conduit. Because of its rarity and special nature, surgical patients with situs inversus may require more flexibility and creativity from the surgical team.
PubMed: 35264880
DOI: 10.2147/IJGM.S295444 -
Cell Apr 2015Breathing is essential for survival and under precise neural control. The vagus nerve is a major conduit between lung and brain required for normal respiration. Here, we...
Breathing is essential for survival and under precise neural control. The vagus nerve is a major conduit between lung and brain required for normal respiration. Here, we identify two populations of mouse vagus nerve afferents (P2ry1, Npy2r), each a few hundred neurons, that exert powerful and opposing effects on breathing. Genetically guided anatomical mapping revealed that these neurons densely innervate the lung and send long-range projections to different brainstem targets. Npy2r neurons are largely slow-conducting C fibers, while P2ry1 neurons are largely fast-conducting A fibers that contact pulmonary endocrine cells (neuroepithelial bodies). Optogenetic stimulation of P2ry1 neurons acutely silences respiration, trapping animals in exhalation, while stimulating Npy2r neurons causes rapid, shallow breathing. Activating P2ry1 neurons did not impact heart rate or gastric pressure, other autonomic functions under vagal control. Thus, the vagus nerve contains intermingled sensory neurons constituting genetically definable labeled lines with different anatomical connections and physiological roles.
Topics: Animals; Brain Stem; Lung; Mice; Receptors, G-Protein-Coupled; Respiration; Sensory Receptor Cells; Vagus Nerve
PubMed: 25892222
DOI: 10.1016/j.cell.2015.03.022 -
Journal of Vascular Surgery Mar 2015Peripheral arterial disease (PAD) continues to grow in global prevalence and consumes an increasing amount of resources in the United States health care system. Overall... (Review)
Review
Peripheral arterial disease (PAD) continues to grow in global prevalence and consumes an increasing amount of resources in the United States health care system. Overall rates of intervention for PAD have been rising steadily in recent years. Changing demographics, evolution of technologies, and an expanding database of outcomes studies are primary forces influencing clinical decision making in PAD. The management of PAD is multidisciplinary, involving primary care physicians and vascular specialists with varying expertise in diagnostic and treatment modalities. PAD represents a broad spectrum of disease from asymptomatic through severe limb ischemia. The Society for Vascular Surgery Lower Extremity Practice Guidelines committee reviewed the evidence supporting clinical care in the treatment of asymptomatic PAD and intermittent claudication (IC). The committee made specific practice recommendations using the GRADE (Grades of Recommendation Assessment, Development and Evaluation) system. There are limited Level I data available for many of the critical questions in the field, demonstrating the urgent need for comparative effectiveness research in PAD. Emphasis is placed on risk factor modification, medical therapies, and broader use of exercise programs to improve cardiovascular health and functional performance. Screening for PAD appears of unproven benefit at present. Revascularization for IC is an appropriate therapy for selected patients with disabling symptoms, after a careful risk-benefit analysis. Treatment should be individualized based on comorbid conditions, degree of functional impairment, and anatomic factors. Invasive treatments for IC should provide predictable functional improvements with reasonable durability. A minimum threshold of a >50% likelihood of sustained efficacy for at least 2 years is suggested as a benchmark. Anatomic patency (freedom from restenosis) is considered a prerequisite for sustained efficacy of revascularization in IC. Endovascular approaches are favored for most candidates with aortoiliac disease and for selected patients with femoropopliteal disease in whom anatomic durability is expected to meet this minimum threshold. Conversely, caution is warranted in the use of interventions for IC in anatomic settings where durability is limited (extensive calcification, small-caliber arteries, diffuse infrainguinal disease, poor runoff). Surgical bypass may be a preferred strategy in good-risk patients with these disease patterns or in those with prior endovascular failures. Common femoral artery disease should be treated surgically, and saphenous vein is the preferred conduit for infrainguinal bypass grafting. Patients who undergo invasive treatments for IC should be monitored regularly in a surveillance program to record subjective improvements, assess risk factors, optimize compliance with cardioprotective medications, and monitor hemodynamic and patency status.
Topics: Asymptomatic Diseases; Endovascular Procedures; Humans; Intermittent Claudication; Lower Extremity; Patient Selection; Peripheral Arterial Disease; Risk Factors; Severity of Illness Index; Treatment Outcome; Vascular Patency; Vascular Surgical Procedures
PubMed: 25638515
DOI: 10.1016/j.jvs.2014.12.009 -
Vascular Cell 2014A decline in the function of the microvasculature occurs with ageing. An impairment of endothelial properties represents a main aspect of age-related microvascular... (Review)
Review
A decline in the function of the microvasculature occurs with ageing. An impairment of endothelial properties represents a main aspect of age-related microvascular alterations. Endothelial dysfunction manifests itself through a reduced angiogenic capacity, an aberrant expression of adhesion molecules and an impaired vasodilatory function. Increased expression of adhesion molecules amplifies the interaction with circulating factors and inflammatory cells. The latter occurs in both conduit arteries and resistance arterioles. Age-related impaired function also associates with phenotypic alterations of microvascular cells, such as endothelial cells, smooth muscle cells and pericytes. Age-related morphological changes are in most of cases organ-specific and include microvascular wall thickening and collagen deposition that affect the basement membrane, with the consequent perivascular fibrosis. Data from experimental models indicate that decreased nitric oxide (NO) bioavailability, caused by impaired eNOS activity and NO inactivation, is one of the causes responsible for age-related microvascular endothelial dysfunction. Consequently, vasodilatory responses decline with age in coronary, skeletal, cerebral and vascular beds. Several therapeutic attempts have been suggested to improve microvascular function in age-related end-organ failure, and include the classic anti-atherosclerotic and anti-ischemic treatments, and also new innovative strategies. Change of life style, antioxidant regimens and anti-inflammatory treatments gave the most promising results. Research efforts should persist to fully elucidate the biomolecular basis of age-related microvascular dysfunction in order to better support new therapeutic strategies aimed to improve quality of life and to reduce morbidity and mortality among the elderly patients.
PubMed: 25243060
DOI: 10.1186/2045-824X-6-19 -
Diagnostic and Interventional Imaging Feb 2022Postoperative imaging plays a key role in the identification of complications after Ivor-Lewis esophagectomy (ILE). Careful analysis of imaging examinations can help... (Review)
Review
Postoperative imaging plays a key role in the identification of complications after Ivor-Lewis esophagectomy (ILE). Careful analysis of imaging examinations can help identify the cause of the presenting symptoms and the mechanism of the complication. The complex surgical procedure used in ILE results in anatomical changes that make imaging interpretation challenging for many radiologists. The purpose of this review was to make radiologists more familiar with the imaging findings of normal anatomical changes and those of complications following ILE to enable accurate evaluation of patients with an altered postoperative course. Anastomotic leak, gastric conduit necrosis and pleuropulmonary complications are the most serious complications after ILE. Computed tomography used in conjunction with oral administration of contrast material is the preferred diagnostic tool, although it conveys limited sensitivity for the diagnosis of anastomotic fistula. In combination with early endoscopic assessment, it can also help early recognition of complications and appropriate therapeutic management.
Topics: Anastomotic Leak; Esophageal Neoplasms; Esophagectomy; Humans; Postoperative Complications; Retrospective Studies
PubMed: 34654670
DOI: 10.1016/j.diii.2021.09.003 -
Indian Journal of Thoracic and... Jan 2021Patients with transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction are managed by various techniques.... (Review)
Review
Patients with transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction are managed by various techniques. Traditional techniques include intracardiac baffling with a right ventricle to pulmonary artery conduit (Rastelli procedure) and the "reparation a l'etage ventriculaire" (REV) procedure. However, other techniques such as aortic root translocation (Bex-Nikaidoh procedure), pulmonary root translocation, and double root translocation are equivalent or in fact provide better results than the traditional techniques. In this review we will have a detailed discussion about aortic root translocation which allows a more normal and anatomically aligned left ventricular outflow tract. However, the operation is technically demanding, and coronary translocation remains one of the major challenges for successful root translocation.
PubMed: 33603284
DOI: 10.1007/s12055-020-00956-7 -
Tomography (Ann Arbor, Mich.) Jun 2023The skull base provides a platform for supporting the brain while serving as a conduit for major neurovascular structures. In addition to malignant lesions originating... (Review)
Review
The skull base provides a platform for supporting the brain while serving as a conduit for major neurovascular structures. In addition to malignant lesions originating in the skull base, there are many benign entities and developmental variants that may simulate disease. Therefore, a basic understanding of the relevant embryology is essential. Lesions centered in the skull base can extend to the adjacent intracranial and extracranial compartments; conversely, the skull base can be secondarily involved by primary extracranial and intracranial disease. CT and MRI are the mainstay imaging methods and are complementary in the evaluation of skull base lesions. Advances in cross-sectional imaging have been crucial in the management of patients with skull base pathology, as this represents a complex anatomical area that is hidden from direct clinical exam. Furthermore, the clinician must rely on imaging studies for therapy planning and to monitor treatment response. It is crucial to have a thorough understanding of skull base anatomy and its various pathologies, as well as to recognize the appearance of treatment-related changes. In this review, we aim to describe skull base tumors and tumor-like lesions in an anatomical compartmental approach and present imaging methods that aid in diagnosis, management, and follow-up.
Topics: Humans; Skull Base Neoplasms; Diagnostic Imaging; Brain
PubMed: 37489465
DOI: 10.3390/tomography9040097 -
American Journal of Botany Apr 2021Gymnosperm taxa are incredibly diverse in many traits, including taxa with evergreen or deciduous leaves; broad, compound, needle-like or scale-like leaves; trees,... (Review)
Review
Gymnosperm taxa are incredibly diverse in many traits, including taxa with evergreen or deciduous leaves; broad, compound, needle-like or scale-like leaves; trees, shrubs, and lianas; and taxa with seed cones that range from fleshy to woody. Although less appreciated, xylem conduits are also diverse in structure among extant gymnosperm taxa. Within the xylem of gymnosperms, axial transport occurs predominantly via tracheids, although 10-40% of gymnosperm taxa, particularly within the Gnetophyta and Cycadophyta, also contain vessels. Gymnosperm taxa vary greatly in their inter-conduit pit structure, with different types of pit membranes and pitting arrangements. While some taxa display torus-margo bordered pits (60%), many others do not contain tori (40%), and at least some taxa without tori occur within each of the four extant phyla (Coniferophyta, Cycadophyta, Ginkgophyta, and Gnetophyta). Pit membrane types vary within families but appear relatively conserved within genera. Woody species with torus-bearing pit membranes occur in colder environments (lower mean annual temperature) compared to those without tori; but occurrence does not differ with mean annual precipitation. Detailed descriptions of pit membrane types are lacking for many species and genera, indicating a need for increased anatomical study. Increased knowledge of these traits could provide a unique experimental context in which to study the evolution of conduit networks, the hydraulic implications of conduit and pit structure, and the diverse structural and functional strategies utilized by gymnosperms. There are myriad potential study questions and research opportunities within this unique and diverse group of plants.
Topics: Cycadopsida; Tracheophyta; Trees; Water; Xylem
PubMed: 33861866
DOI: 10.1002/ajb2.1641