The sub-peritoneal arterial plexus of Sir William Turner

The potential mechanisms underlying the modulating effect of perirenal adipose tissue on hypertension: Physical compression, paracrine, and neurogenic regulation

Hypertension, a prevalent global cardiovascular disease, affects approximately 45.4 % of adults worldwide. Despite advances in therapy, hypertension continues to pose a significant health risk due to inadequate management. It has been established that excessive adiposity contributes majorly to hypertension, accounting for 65 to 75 % of primary cases. Fat depots can be categorised into subcutaneous and visceral adipose tissue based on anatomical and physiological characteristics. The metabolic impact and the risk of hypertension are determined more significantly by visceral fat. Perirenal adipose tissue (PRAT), a viscera enveloping the kidney, is known for its superior vascularisation and abundant innervation. Although traditionally deemed as a mechanical support tissue, recent studies have indicated its contributing potential to hypertension. Hypertensive patients tend to have increased PRAT thickness compared to those without, and there is a positive correlation between PRAT thickness and elevated systolic blood pressure. This review encapsulates the anatomical characteristics and biogenesis of PRAT. We provide an overview of the potential mechanisms where PRAT may modulate blood pressure, including physical compression, paracrine effects, and neurogenic regulation. PRAT has become a promising target for hypertension management, and continuous effort is required to further explore the underlying mechanisms.

HISTOLOGIC AND MORPHOLOGIC CHARACTER OF PEDIATRIC ABDOMINAL AORTIC DEVELOPMENTAL COARCTATION AND HYPOPLASIA

OBJECTIVES

Abdominal aortic coarctation and hypoplasia are uncommon diseases, recognized most often in pediatric-aged individuals. Comprehensive studies regarding the pathologic spectrum of these aortopathies are nonexistent. This investigation was undertaken to better define the histologic and morphologic character of abdominal aortic narrowings affecting children and assess its potential relevance to contemporary clinical practice.

METHODS

Aortic specimens obtained during open operations in children being treated for symptomatic, noninflammatory abdominal aortic narrowings at the University of Michigan were subjected to histologic study following hematoxylin-eosin, Movat, Verhoeff Van Gieson, and Masson's trichrome preparations. Microscopic findings were correlated with the anatomic aortic images. In addition, a detailed review was completed of all prior reports in the English literature that included images depicting the histologic character of noninflammatory abdominal aortic narrowings in children.

RESULTS

Among a series of 67 pediatric-aged individuals undergoing open surgical interventions for abdominal aortic narrowings, eight children ranging in age from 9 months to 18 years, had adequate aortic tissue available for study. The loci of the specimens paralleled the anatomic sites of segmental coarctations observed in the entire series, with involvement of the suprarenal abdominal aorta (3), intrarenal aorta (2), and infrarenal aorta (1). Diffusely hypoplastic abdominal aortas (2) included one case of a de facto aortic duplication, represented by a channel that paralleled the narrow native aorta and gave origin to celiac artery branches, as well as the superior mesenteric and renal arteries. Concentric or eccentric intimal fibroplasia was observed in every aorta, often with internal elastic fragmentation and duplication (4). Media abnormalities included elastic tissue disorganization (3), and focal medial fibrosis (1). Organizing luminal thrombus occurred in two infants. Coexistent ostial stenoses of the celiac, superior mesenteric, or renal arteries were observed in all but the only child who having an infrarenal aortic coarctation. Neurofibromatosis-1 affected one child whose histologic findings were indistinguishable from those of the other children. Review of prior published histologic images of abdominal aortic coarctation and hypoplasia affecting children from other centers revealed a total of 14 separate reports, each limited to single case photomicrographs of which 11 exhibited intimal fibroplasia.

CONCLUSIONS

Intimal fibroplasia is a common accompaniment of developmental abdominal aortic coarctation and hypoplasia. It is posited that intimal fibroplasia, that is likely progressive in instances of abnormal shear stresses in these diminutive vessels, may contribute to less salutary outcomes following endovascular and certain open reconstructions of pediatric abdominal aortic narrowings.

Variant Arterial Supply of the Descending Colon by the Coeliac Trunk: A Case Report

Background and Objectives: Knowledge of arterial variations of the intestines is of great importance in visceral surgery and interventional radiology. Materials and Methods: An unusual variation in the blood supply of the descending colon was observed in a Caucasian female body donor. Results: In this case, the left colic artery that regularly derives from the inferior mesenteric artery supplying the descending colon was instead a branch of the common hepatic artery. Conclusions: Here, we describe the very rare case of an aberrant left colic artery arising from the common hepatic artery in a dissection study.

Perirenal Adipose Tissue-Current Knowledge and Future Opportunities

The perirenal adipose tissue (PRAT), a component of visceral adipose tissue, has been recently recognized as an important factor that contributes to the maintenance of the cardiovascular system and kidney homeostasis. PRAT is a complex microenvironment consisting of a mixture of white adipocytes and dormant and active brown adipocytes, associated with predipocytes, sympathetic nerve endings, vascular structures, and different types of inflammatory cells. In this review, we summarize the current knowledge about PRAT and discuss its role as a major contributing factor in the pathogenesis of hypertension, obesity, chronic renal diseases, and involvement in tumor progression. The new perspectives of PRAT as an endocrine organ and recent knowledge regarding the possible activation of dormant brown adipocytes are nowadays considered as new areas of research in obesity, in close correlation with renal and cardiovascular pathology. Supplementary PRAT complex intervention in tumor progression may reveal new pathways involved in carcinogenesis and, implicitly, may identify additional targets for tailored cancer therapy.

Coronary Collateral Flow Index Is Correlated With the Palmar Collateral Flow Index: Indicating Systemic Collateral Coherence in Individual Patients-Brief Report

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Perirenal Adipose Tissue Inflammation: Novel Insights Linking Metabolic Dysfunction to Renal Diseases

A healthy adipose tissue (AT) is indispensable to human wellbeing. Among other roles, it contributes to energy homeostasis and provides insulation for internal organs. Adipocytes were previously thought to be a passive store of excess calories, however this view evolved to include an endocrine role. Adipose tissue was shown to synthesize and secrete adipokines that are pertinent to glucose and lipid homeostasis, as well as inflammation. Importantly, the obesity-induced adipose tissue expansion stimulates a plethora of signals capable of triggering an inflammatory response. These inflammatory manifestations of obese AT have been linked to insulin resistance, metabolic syndrome, and type 2 diabetes, and proposed to evoke obesity-induced comorbidities including cardiovascular diseases (CVDs). A growing body of evidence suggests that metabolic disorders, characterized by AT inflammation and accumulation around organs may eventually induce organ dysfunction through a direct local mechanism. Interestingly, perirenal adipose tissue (PRAT), surrounding the kidney, influences renal function and metabolism. In this regard, PRAT emerged as an independent risk factor for chronic kidney disease (CKD) and is even correlated with CVD. Here, we review the available evidence on the impact of PRAT alteration in different metabolic states on the renal and cardiovascular function. We present a broad overview of novel insights linking cardiovascular derangements and CKD with a focus on metabolic disorders affecting PRAT. We also argue that the confluence among these pathways may open several perspectives for future pharmacological therapies against CKD and CVD possibly by modulating PRAT immunometabolism.

Perirenal fat thickness measured with computed tomography is a reliable estimate of perirenal fat mass

Deposition of perirenal adipose tissue has been associated with adverse renal and cardiovascular events. We compared various methods to measure perirenal adipose tissue using computerized tomography (CT)-scan and performed correlations with anthropometric measures associated with renal and cardiovascular events. Voluntary overweight and obese subjects undergoing a CT-scan for diagnostic purposes were included in the study. Perirenal adipose tissue volume, adipose tissue area of the renal sinus and perirenal fat thickness were manually measured bilaterally. The intra- and inter-observer coefficient correlations and the correlation between the diverse measures of renal adipose tissue, subcutaneous (SC-)fat and anthropometrics measures were analyzed using Pearson's correlation tests. The forty included patients (24 men, 16 women) had a mean age of 57.6 ± 18.1 years and a mean body mass index of 28.9 ± 2.9 kg/m². Despite comparable waist circumference, women had a greater SC-fat thickness compared to men, and therefore a smaller amount of visceral fat, as well as smaller perirenal fat volumes. Perirenal fat thickness was better correlated with perirenal fat volume than adipose area of the renal sinus (p <0.02). The adipose area of the renal sinus did not correlate with any anthropometric measures. In women, perirenal fat volume and thickness showed a negative correlation with SC-fat thickness and no correlation with waist circumference. In men, perirenal fat volume and thickness showed a positive correlation with waist circumference and no correlation with subcutaneous fat thickness. In conclusion, perirenal fat thickness measured with CT-scan at the level of the renal veins is a simple and reliable estimate of perirenal fat volume, that correlated negatively with SC-fat in women and positively with waist circumference in men. The adipose area of the renal sinus did not correlate with any anthropometric measure.

Sir William Turner (1832-1916) - Lancastrian, anatomist and champion of the Victorian era

Sir William Turner, a Lancastrian, was renowned as a scientist, anatomist and a great reformer of medical education. His students became anatomists at various international institutions, which consequently shaped the future of anatomy as a subject matter both in the United Kingdom and in South Africa. Although Turner's accomplishments have been documented, little is known about the details that determined his career path and the individuals that shaped his future. Here the authors aim to highlight some aspects of Turner's academic achievements and his personal life as well as how he crossed paths with other great minds of the Victorian era including Richard Owen, Charles Darwin, James Paget and Joseph Lister.

A brief etymology of the collateral circulation

It is well known that the protective capacity of the collateral circulation falls short in many individuals with ischemic disease of the heart, brain, and lower extremities. In the past 15 years, opportunities created by molecular and genetic tools, together with disappointing outcomes in many angiogenic trials, have led to a significant increase in the number of studies that focus on: understanding the basic biology of the collateral circulation; identifying the mechanisms that limit the collateral circulation's capacity in many individuals; devising methods to measure collateral extent, which has been found to vary widely among individuals; and developing treatments to increase collateral blood flow in obstructive disease. Unfortunately, accompanying this increase in reports has been a proliferation of vague terms used to describe the disposition and behavior of this unique circulation, as well as the increasing misuse of well-ensconced ones by new (and old) students of collateral circulation. With this in mind, we provide a brief glossary of readily understandable terms to denote the formation, adaptive growth, and maladaptive rarefaction of collateral circulation. We also propose terminology for several newly discovered processes that occur in the collateral circulation. Finally, we include terms used to describe vessels that are sometimes confused with collaterals, as well as terms describing processes active in the general arterial-venous circulation when ischemic conditions engage the collateral circulation. We hope this brief review will help unify the terminology used in collateral research.

Anterior retroperitoneal rami: until now unnamed direct branches of the abdominal aorta

The aim of the study was to gain a thorough knowledge of the topography and distribution of until now officially unnamed minute direct branches from abdominal aorta, stemming from its ventral and lateral aspects, supplying surrounding tissue, and to comprise it to the existing studies. The study was performed in fixed cadaverous material collected from India ink injections of abdominal aorta samples with large surrounding retroperitoneal tissue. The 25 samples were dissected under magnifying binocular glass, followed by graphic reconstruction; statistical analysis, and the study was preceded with detailed review of branches from abdominal aorta. For systematization of the segmental anatomy of the abdominal aorta and infrarenal segment of inferior vena cava, we defined three levels in this area. The retroperitoneal branches were most frequently situated simultaneously within all three predefined levels according to renal and inferior mesenteric arteries origin. There were 18% of retroperitoneal branches within Level 1, 39% within Level 2 and 43% within Level 3. They were branches not only from the abdominal aorta, but also from the testicular/ovarian artery, common iliac artery and in one case from the right accessory renal artery. Paired arrangement was recorded mainly cranially to the origin of inferior mesenteric artery, unpaired branches were more frequently found caudally. In conclusion, due to the terminological disunity of these arteries in the clinical literature and total absence in the anatomical literature, we propose to denominate them as anterior retroperitoneal branches of abdominal aorta (rami retroperitoneales anteriores aortae abdominalis).

Single ectopic main right renal artery originating from the coeliac axis

We present a rare case of an ectopic main right renal artery originating as part of the coeliac axis. Renal arteries are usually paired vessels which originate directly from the aorta to supply each kidney. Variations in their origin and numbers have been reported by many authors. However, there has only been one previous report of a left main renal artery arising from the coeliac axis in the medical literature, in 1980, seen during angiography. We believe we have the first CT angiographic evidence of such anatomy. This important aberrant anatomy must be noted not only for its rarity but also for its implications in the field of transplant surgery and interventional radiology. There will be more similar reports as non-invasive imaging is being used ever more frequently.