Cholangiopancreatography in cats: a post-mortem comparison of MRI with fluoroscopy, corrosion casting and histopathology.

In human medicine, magnetic resonance cholangiopancreatography (MRCP) is a valuable diagnostic tool for hepatobiliary and pancreatic diseases. In veterinary medicine, however, data evaluating the diagnostic value of MRCP are limited. The primary objectives of this prospective, observational, analytical investigation were to assess whether MRCP reliably visualizes the biliary tract and pancreatic ducts in cats without and with related disorders, and whether MRCP images and measurements of the ducts agree with those of fluoroscopic retrograde cholangiopancreatography (FRCP), corrosion casting and histopathology. A secondary objective was to provide MRCP reference diameters for bile ducts, GB, and pancreatic ducts. Donated bodies of 12 euthanized adult cats underwent MRCP, FRCP, and autopsy with corrosion casting of the biliary tract and pancreatic ducts using vinyl polysiloxane. Diameters of the biliary ducts, gallbladder (GB), and pancreatic ducts were measured using MRCP, FRCP, corrosion casts and histopathologic slides. There was an agreement between MRCP and FRCP in measuring diameters of the GB body, GB neck, cystic duct, and common bile duct (CBD) at papilla. Strong positive correlations existed between MRCP and corrosion casting for measuring GB body and neck, cystic duct, and CBD at the extrahepatic ducts' junction. In contrast to the reference methods, post-mortem MRCP did not visualize right and left extrahepatic ducts, and pancreatic ducts in most cats. Based on this study, MRCP with 1.5 Tesla can be regarded as a contributory method to improve the assessment of feline biliary tract and pancreatic ducts when their diameter is >1 mm.

Non-linear shrinkage of Batson's #17 resin during vascular corrosion casting.

Many studies of cardiovascular function require a realistic representation of vascular geometry. Corrosion casting has been used to acquire such geometries for many decades. However, the fidelity with which this method reproduces vascular anatomy has not been completely determined. Here we report on the non-linear shrinkage characteristics and exothermic properties of Batson's #17, a widely used casting resin, in model systems and in aortas of rats and rabbits. The setting process was captured using high-resolution photography. Shrinkage ranged from 3.4 ± 1.5% of the diameter in 1 ml plastic syringes (inner diameter 4.8 mm) to 19.6 ± 5.6% in the aorta of rats (diameter 1.5-2.6 mm). In addition, aortic curvature and branching angles changed during setting. These effects should be determined and corrected in studies of vascular geometry where high accuracy is required.

A Method to Visualize and Quantify the Intraosseous Arteries of the Femoral Head by Vascular Corrosion Casting.

OBJECTIVE: To describe a method to display the three-dimensional distribution of intraosseous arteries in the femoral head by vascular corrosion casting. METHODS: An experimental study was done to expose the intraosseous arteries of the femoral head by a microperfusion corrosion method between January 2021 and May 2021. Specimens were 23 swine femoral heads (12 female specimens and 11 male specimens, where age of swine ranged from 8 to 12 months, and the weight was approximately 150 kg). The femoral heads were microperfused with the vascular casting resin through retinacular arteries, and the bone of the femoral head was dissolved with 50% sodium hydroxide and 10% hydrochloric acid and rinsed under the microscope until the vessel casts were completely exposed. The distribution and anastomosis of the arteries in the femoral head were observed under direct vision and microscopy. The diameter of the artery in the femoral head was measured at 0.5 cm after its entry into the bone of the femoral head with a microscale under the microscope. The number of internal arteries with diameter ≥0.05 mm was counted. The number and diameter of the main trunk of the epiphyseal arteries in the femoral head between male and female swine were compared. RESULTS: The vascular casting specimen of the swine femoral head was successfully produced by using epoxy resin as a casting agent, and the three-dimensional intraosseous vascular structures were clearly visible. The number of epiphyseal arteries in male and female swine was 8.55 ± 2.15 and 8.83 ± 2.15 (t = -0.31, p = 0.38), respectively. The diameters of the superior epiphyseal arteries in male and female swine were 0.35 ± 0.09 and 0.31 ± 0.08 mm (t = 1.03, p = 0.16), the diameters of the inferior epiphyseal arteries were 0.47 ± 0.05 and 0.49 ± 0.09 mm (t = -0.57, p = 0.29), and the diameters of the anterior epiphyseal arteries were 0.34 ± 0.08 and 0.33 ± 0.13 mm (t = 0.32, p = 0.37). There was no significant difference in the number and diameter of the main trunk of intraosseous arteries between male and female swine (p > 0.05). The main trunk of intraosseous arteries formed an anastomosis in the center of the femoral head. Among 23 swine femoral head samples, three types of intraosseous anastomosis were observed, including 13 (57%) posterior superior-posterior inferior, seven (30%) posterior inferior-anterior, and three (13%) uniform intraosseous anastomosis. CONCLUSION: The microperfusion corrosion method can produce the vascular casting specimen of swine femoral head revealing the three-dimensional structure of the intraosseous artery, which clearly shows the origin, course and branches, and diameter, as well as the anastomosis, of nutrient arteries in the femoral head. This method provides a simple and rapid technique for quantifying and visualizing intraosseous arteries.

Endothelialitis, Microischemia, and Intussusceptive Angiogenesis in COVID-19.

COVID-19 has been associated with a range of illness severity-from minimal symptoms to life-threatening multisystem organ failure. The severe forms of COVID-19 appear to be associated with an angiocentric or vascular phase of the disease. In studying autopsy patients succumbing to COVID-19, we found alveolar capillary microthrombi were 9 times more common in COVID-19 than in comparable patients with influenza. Corrosion casting of the COVID-19 microcirculation has revealed microvascular distortion, enhanced bronchial circulation, and striking increases in intussusceptive angiogenesis. In patients with severe COVID-19, endothelial cells commonly demonstrate significant ultrastructural injury. High-resolution imaging suggests that microcirculation perturbations are linked to ischemic changes in microanatomic compartments of the lung (secondary lobules). NanoString profiling of these regions has confirmed a transcriptional signature compatible with microischemia. We conclude that irreversible tissue ischemia provides an explanation for the cystic and fibrotic changes associated with long-haul COVID-19 symptoms.

Spatial architecture of biliary tree in mammals: Fractal and Euclidean geometric features.

The study of the fractal architecture of various organs and structures expanded the possibilities for determining the ranges of their functioning and structural arrangement, which, as a result, was reflected in the development of new approaches to diagnostics and therapeutic impacts. The architecture of the excretory duct systems, similar to the hemo- and lymph- circulatory beds and the bronchial tree, is considered fractal. At the same time, information about hitherto unknown structures of the biliary tree continues to appear in the literature. We aimed to study the features of the spatial geometry of the biliary tree and assess the significance of both its fractal and Euclidean characteristics for the development of approaches that facilitate comprehensive description of intrahepatic biliary tract architecture. We investigated the architecture of the biliary trees of six men, seven male canines, and seven male Wistar rats using the corrosion casting method. Corrosion casts were prepared by injecting solidifying latexes into the bile ducts. The preparations were studied using a light stereomicroscope and a scanning electron microscope. Biliary tree branching is of various types. In addition, the correlation between variations in the caliber and length of the bile ducts and their order is not significant. Therefore, the biliary tree should not be considered as a classical fractal and it consists of the main modules, represented by the network of the bile canaliculi (first nonfractal module) and a biliary tree with a fractal branching (second module) that drains the bile canaliculi mesh and the additional modules represented by the mucosal biliary glands (in mammals with the gallbladder) or the periportal biliary plexus (in mammals without a gallbladder) and the aberrant biliary ducts. Such a configuration of the biliary bed should optimally ensure the smooth implementation of the physiological function of the liver, as well as its adaptation to different pathologies accompanied by biliary hypertension. It also might be considered in the diagnosis and assessment of ductular reaction, biliary regeneration, and/or carcinogenesis.

Accelerating neovascularization and kidney tissue formation with a 3D vascular scaffold capturing native vascular structure.

Establishing an adequate vascularization of three-dimensional (3D) bioengineered tissues remains a critical challenge. We previously fabricated a vascular scaffold using the vascular corrosion casting technique, which provides a similar 3D geometry of native kidney vasculature. In this study, we functionalized the collagen vascular scaffold with a controlled release of vascular endothelial growth factor (VEGF vascular scaffold) to further promote vascularization. The VEGF vascular scaffold showed improved angiogenic capability in 2-dimensional (2D) and 3D in vitro settings. Implantation of the VEGF vascular scaffold seeded with human renal cells into a rat kidney demonstrated enhanced implant vascularization and reduced apoptosis of implanted human renal cells. Hybrid renal tubule-like structures composed of implanted human and migrated host renal cells were formed. This work highlights the critical role of early vascularization of the geometrically mimetic vascular scaffold using the VEGF incorporated vascular scaffold in reducing apoptosis of implanted cells as well as the formation of renal tissue structures.

Analysis of spinal cord blood supply combining vascular corrosion casting and fluorescence microsphere technique: A feasibility study in an aortic surgical large animal model.

INTRODUCTION: Spinal cord ischemia after cardiovascular interventions continues to be a devastating problem in modern surgery. The role of intraspinal vascular networks and anterior radiculomedullary arteries (ARMA) in preventing spinal cord ischemia is poorly understood. MATERIALS AND METHODS: Landrace pigs (n = 30, 35.1 ± 3.9 kg) underwent a lateral thoracotomy. Fluorescent microspheres were injected into the left atrium and a reference sample was aspirated from the descending aorta. Repeated measurements of spinal cord and renal cortical blood flow from the left and right kidneys with three different microsphere colors in five pigs were taken to validate reproducibility. Spinal cord blood flow to the upper thoracic (T1-T4), mid-thoracic (T5-T8), lower thoracic (T9-T13), and lumbar (L1-L3) levels were determined. After euthanasia, we carried out selective vascular corrosion cast and counted the left and right ARMAs from levels T1-T13. RESULTS: Blood flow analysis of the left and right kidneys revealed a strong correlation (r = .94, p < .001). We detected more left than right ARMAs, with the highest prevalence at T4 (p < .05). The mean number of ARMAs was 8 ± 2. Their number in the upper thoracic region ranged from 2 to 7 (mean of 5 ± 1), while in the lower thoracic region they ranged from 0 to 5 (mean of 3 ± 1 [p < .001]). CONCLUSIONS: This study shows that combining fluorescence microsphere technique and vascular corrosion cast is well suited for assessing the blood flow and visualizing the arteries at the same time.

Historical anatomy of hepatic segmentation: about 250 livers corrosions by Rapp (1953) and Couinaud (1953) in the Conservatory of Anatomy in Montpellier.

Two "surgeons-anatomists" Rapp in Montpellier and Couinaud in Paris at the same period (1953) given precise anatomy useful for the hepatic surgery and to the tremendous upheavals of radiological investigations. Actually, the fundamental anatomy of liver is classic with 8 segments with autonomous territories having a vascular afferent pedicle and a venous and biliary efferent drainage. These autonomous territories supported the surgical approach of the liver with the possibility of resecting a hepatic territory in a carcinological perspective well saving quite vascularized parenchyma. It will be in the future history about liver morphology to specify the contribution of these two "surgeons-anatomists". Actually it will be possible to look in the "Conservatory of Anatomy" in Montpellier these original livers corrosions.

On the characterization of functionally graded biomaterial primed through a novel plaster mold casting process.

The current work presents a novel plaster mold casting (PMC) process for fabricating functionally graded biodegradable materials (FGBMs) for orthopedics applications. According to the proposed route, the plaster molds were first prepared by using a hybrid and variable mixture of Plaster of Paris (PoP) and hydroxyapatite (HAP). Upon drying, molten magnesium (Mg) alloy was poured in the mold cavity and allowed to solidify. Various experiments have been conducted as per Taguchi based design of experimentation to study the effect of PoPX/HAP proportion, mixing time, and baking times on mechanical, corrosion, and cytocompatibility performances of the resulting FGBM. It has been revealed by the scanning electron microscopy (SEM) that uniform layers of HAP particles were developed on the prepared specimens, revealed the novelty of the route. The mechanical properties, in case of surface hardness and impact strength, the optimum results were obtained with PoP(x = 90% by wt.) and HAP(y = 10% by wt.). Further, the corrosion investigations highlighted that the sample prepared with PoP(x = 70% by wt.) and HAP(y = 30% by wt.) proportion possessed excellent corrosion resistance. Moreover, the cytocompatibility analysis revealed that all the developed FGBM are substantially bioactive and promoted cell adhesion, proliferation, differentiation, and various other cytoplasmic activities. However, in this case, FGBM with PoP(x = 70% by wt.) and HAP(y = 30% by wt.) proportion was found superior. The overall results of the present work supported the developed FGBM components and involved the PMC route as a potential candidate for various orthopedics fabrications.

Kidney regeneration with biomimetic vascular scaffolds based on vascular corrosion casts.

We have developed a biomimetic renal vascular scaffold based on a vascular corrosion casting technique. This study evaluated the feasibility of using this novel biomimetic scaffold for kidney regeneration in a rat kidney cortical defect model. Vascular corrosion casts were prepared from normal rat kidneys by perfusion with 10% polycaprolactone (PCL) solution, followed by tissue digestion. The corrosion PCL cast was coated with collagen, and PCL was removed from within the collagen coating, leaving only a hollow collagen-based biomimetic vascular scaffold. The fabricated scaffolds were pre-vascularized with MS1 endothelial cell coating, incorporated into 3D renal constructs, and subsequently implanted either with or without human renal cells in the renal cortex of nude rats. The implanted collagen-based vascular scaffold was easily identified and integrated into native kidney tissue. The biomimetic vascular scaffold coated with endothelial cells (MS1) showed significantly enhanced vascularization, as compared to the uncoated scaffold and hydrogel only groups (P < 0.001). Along with the improved vascularization effects, the MS1-coated scaffolds showed a significant renal cell infiltration from the neighboring host tissue, as compared to the other groups (P < 0.05). Moreover, addition of human renal cells to the MS1-coated scaffold resulted in further enhancement of vascularization and tubular structure regeneration within the implanted constructs. The biomimetic collagen vascular scaffolds coated with endothelial cells are able to enhance vascularization and facilitate the formation of renal tubules after 14 days when combined with human renal cells. This study shows the feasibility of bioengineering vascularized functional renal tissues for kidney regeneration. STATEMENT OF SIGNIFICANCE: Vascularization is one of the major hurdles affecting the survival and integration of implanted three-dimensional tissue constructs in vivo. A novel, biomimetic, collagen-based vascular scaffold that is structurally identical to native kidney tissue was developed and tested. This biomimetic vascularized scaffold system facilitates the development of new vessels and renal cell viability in vivo when implanted in a partial renal defect. The use of this scaffold system could address the challenges associated with vascularization, and may be an ideal treatment strategy for partial augmentation of renal function in patients with chronic kidney disease.

Microvascular anatomy of olfactory and accessory olfactory (vomeronasal) organs in adult Xenopus laevis: scanning electron microscopy of vascular corrosion casts / Anatomía microvascular de órganos olfatorios y accesorios (vomeronasal) en adultos Xenopus laevis: microscopía electrónica de barrido de moldes de corrosión vascular

Microvascular anatomy and histomorphology of olfactory and vomeronasal organs in adult Xenopus laevis Daudin were studied by scanning electron microscopy of vascular corrosion casts and paraplast embedded stained serial tissue sections. Results show that the arterial supply is bilaterally by terminal arterioles of the medial branch of the nasal artery and by the palatal artery. Arterioles give rise to a capillary meshwork characteristic for respiratory surfaces in principal chambers and in dorsal and caudal areas of middle chambers. Anterior and inferior areas of the middle chambers own a distinctly different capillary network with conspicuous short capillary loops. Loops have a dilated tip and extend in acute angles towards the chamber lumen. The vomeronasal organ (VNO) locates beneath the olfactory organ. It has a medial to lateral extension and attaches with its caudal circumference to the medial nasal glands. Its capillary bed displays rectangular meshes which preferentially orientate along the long axis of the VNO. Locally, capillaries form short hairpin-like or strongly twisted loops with dilated tips which point towards the lumen of the VNO. These capillaries slow-down blood velocity and may lead to an increased exchange of oxygen, nutrients and water-borne odorants in the middle chambers and of pheromones in the VNO. In the latter vascular structures are present which might serve as a vascular pump.

Se estudiaron la anatomía microvascular e histomorfología de los órganos olfatorios y vomeronasales de Xenopus laevis Daudin adultos, mediante microscopía electrónica de barrido de moldes de corrosión vascular y secciones de tejido seriadas, teñidas e incluídas en paraplast. Los resultados muestran que el suministro arterial es bilateral por arteriolas terminales de la rama medial de la arteria nasal y por la arteria palatina. Las arteriolas dan lugar a un lecho capilar característico de las superficies respiratorias en las cámaras principales y en las áreas dorsal y caudal de las cámaras intermedias. Las áreas anterior e inferior de las cámaras centrales poseen una red capilar significativamente diferente con llamativos bucles capilares cortos. Los bucles tienen una punta dilatada y se extienden en ángulos agudos hacia la luz de la cámara. El órgano vomeronasal (VNO) se ubica debajo del órgano olfatorio. Se extiende de medial a lateral y se une con su circunferencia caudal a las glándulas nasales mediales. El lecho capilar muestra mallas rectangulares que se orientan preferentemente a lo largo del eje longitudinal del VNO. Localmente, los capilares forman bucles cortos en forma de horquilla o fuertemente retorcidos con puntas dilatadas que apuntan hacia la luz del VNO. Estos capilares ralentizan la velocidad de la sangre y pueden conducir a un mayor intercambio de oxígeno, nutrientes y odorizantes, a base de agua en las cámaras intermedias y de feromonas, en el VNO. En este último, están presentes estructuras vasculares que podrían servir como una bomba vascular.

Vascular architecture in free flaps: Analysis of vessel morphology and morphometry in murine free flaps.

The aim of this study was to analyze the development of vascular architecture as well as vascular morphometry and morphology of anastomosed microvascular free flaps. Free pectoral skin flaps were raised in 25 rats and anastomosed to the femoral vessels in the groin region. CD31 immunohistology was performed after 3, 7 and 12 d (each 5 animals each) to analyze microvessel density (MVD), microvessel area (MVA) and microvessel size (MVS). Microvascular corrosion casting was performed after 7 and 12 d (5 animals each) to analyze vessel diameter (VD), intervascular distance (IVD), interbranching distance (IBD), and branching angle (BA). Further on, sprout and pillar density as hallmarks of sprouting and intussusceptive angiogenesis were analyzed. Pectoral skin isles from the contralateral side served as controls. A significantly increased MVD was found after 7 and 12 d (p each <0.001). MVA was significantly increased after 3, 7 and 12 d (p each <0.001) and a significantly increased MVS was analyzed after 3 and 7 d (p each <0.001). VD and IVD were significantly increased after 7 and 12 d (p each <0.001). For IBD, a significantly increase was measured after 7 d (p < 0.001). For IBA, sprout and pillar density, no significant differences were found (p each ≥0.05). Significant changes in the vascular architecture of free flaps after successful microvascular anastomosis were seen. Since there was no evidence for sprout and pillar formation within the free flaps, the increased MVD and flap revascularization might be induced by the receiving site.

Arterial and microvascular supply of cerebral hemispheres in the nude mouse revealed using corrosion casting and scanning electron microscopy.

Morphological analyses of cerebral vascularization are not only important for the characterization of the anatomical and physiological relationships between vascular and nervous tissue, but also required to understand structural modifications that occur in many pathological conditions affecting the brain. The aim of this study was to generate a three-dimensional vascular map of the cerebral hemispheres in the nude mouse brain, a widely used animal model for studying tumour biology. We used the corrosion casting (CC) technique to isolate blood vessels from 30 nude mouse brains. All casts were analysed using scanning electron microscopy (SEM), which generated quantitative data regarding vessel length and diameter as well as inter-vascular and inter-branching distances. We identified three different topographical regions: (i) the cortical region, characterized by a superficial wide sheet of vessels giving rise to terminal perforant vessels that penetrate the grey matter; (ii) the inner part of the grey matter, in which dense capillary nets form many flake-like structures extending towards the grey-white matter boundary, where perforant vessels finally change direction and form a well-defined vascular sheet; and (iii) the white matter layer, characterized by a more disorganized vascular architecture. In this study, we demonstrate the accuracy of the CC-SEM method in revealing the 3D-topographical organization of the vascular network of the normal nude mouse brain. These baseline data will serve as a reference for future anatomical investigations of pathological alterations, such as tumour infiltrations, using the nude mouse model.

Pancreaticoduodenal arterial arcades: Their dominance and variations-their potential clinical relevance.

The complex arterial system makes pancreatic interventions technically challenging for surgeons, and interventional radiologists. The arterial variants may alter tumor resecability, and cause complications in arterial embolization. International data on pancreatic blood supply are variable; therefore, we aimed to determine the frequency of variants of pancreaticoduodenal (PD) arterial arcades. Arteries of human abdominal organ complexes (50) were injected with resin mixture, and then corroded. CT scans and three-dimensional reconstructions were made; diameters of arcades were measured. Two PD arcades were found in 58%, three arcades in 30%, one arcade in three cases, four arcade in one specimen, and five arcades in two cases. In the casts with two arches the average diameter was 1.472 ± 0.432 mm on the anterior and 1.383 ± 0.343 mm on the posterior arch. Assessing the dominance of the PD arcades, the anterior arch proved to be dominant in 52% of the cases, and in 35% the posterior one by the criterion of 25% cross-section difference. It is advised to analyze the variations and dominance on a CT/MR-angiography before local chemotherapy. Furthermore, to reveal the arterial variations, a preoperative CT/MR-angiography would provide faster recuperation and better postoperative life quality. Clin. Anat. 31:544-550, 2018. © 2018 Wiley Periodicals, Inc.

Corrosion casting, a known technique for the study and teaching of vascular and duct structure in anatomy / Inyección corrosión, una técnica conocida para el estudio y enseñanza de ductos y estructuras vasculares en anatomía

Teaching and learning anatomy, as a process, has changed. Fresh cadavers were once used as a tool for the student to approach the human body in order to overcome theoretical knowledge and gain applied expertise. Today, techniques such as corrosion casting are known to be a more effective way of achieving optimal results with the students. This paper examines a method to apply this technique to an organ using different polymers. The concentrations for acrylic, epoxy resin, polyester resin, and room temperature vulcanization (RTV) silicone are described, as well as the corresponding diameter of the duct to be injected with each one. A variety of specimens obtained using this technique, their qualities and characteristics are presented. The results of using these procedures while involving the students, showed increased sense of responsibility, dedication and awareness, which led them to take the class more seriously and enjoy the process of learning. Additionally, the specimens left by the students will help future classes reduce the number of specimens needed.

El proceso de aprendizaje y enseñanza en anatomía ha cambiado recientemente, el cadáver fue la primera herramienta que permitía al estudiante una aproximación practica al cuerpo humano, facilitando que este se sobrepusiera al conocimiento teórico adquirido en el aula, y desarrollara experticia aplicada. Hoy en día, técnicas como la inyección corrosión son conocidas por lograr mejores resultados con los estudiantes. Este trabajo presenta un método para aplicar esta técnica a un órgano, mediante el uso de diferentes polímeros. Las concentraciones adecuadas de acrílico, resina epoxica, resina poliéster, y silicona RTV (room temperature vulcanization) son descritas, así como el diámetro sugerido para el uso de cada polímero. Se presenta una variedad de especímenes obtenidos mediante esta técnica, así como sus cualidades y características. Al integrar a los estudiantes en el proceso de creación de los especímenes, estos demuestran mayor sentido de responsabilidad, dedicación y autoconciencia, generando mayor compromiso, y entusiasmo con la clase y el proceso de aprendizaje. Adicionalmente, los especímenes producidos por ellos, serán de gran utilidad para clases a futuro.

Impact of platelet rich plasma and adipose stem cells on lymphangiogenesis in a murine tail lymphedema model.

BACKGROUND: Lymphedema is an underdiagnosed pathology which in industrialized countries mainly affects cancer patients that underwent lymph node dissection and/or radiation. Currently no effective therapy is available so that patients' life quality is compromised by swellings of the concerned body region. This unfortunate condition is associated with body imbalance and subsequent osteochondral deformations and impaired function as well as with an increased risk of potentially life threatening soft tissue infections. METHODS: The effects of PRP and ASC on angiogenesis (anti-CD31 staining), microcirculation (Laser Doppler Imaging), lymphangiogenesis (anti-LYVE1 staining), microvascular architecture (corrosion casting) and wound healing (digital planimetry) are studied in a murine tail lymphedema model. RESULTS: Wounds treated by PRP and ASC healed faster and showed a significantly increased epithelialization mainly from the proximal wound margin. The application of PRP induced a significantly increased lymphangiogenesis while the application of ASC did not induce any significant change in this regard. CONCLUSIONS: PRP and ASC affect lymphangiogenesis and lymphedema development and might represent a promising approach to improve regeneration of lymphatic vessels, restore disrupted lymphatic circulation and treat or prevent lymphedema alone or in combination with currently available lymphedema therapies.

Extrahepatic arteries of the human liver - anatomical variants and surgical relevancies.

The purpose of our study was to investigate the anatomical variations of the extrahepatic arterial structures of the liver with particular attention to rare variations and their potential impact on liver surgery. A total of 50 human abdominal organ complexes were used to prepare corrosion casts. A multicomponent resin mixture was injected into the abdominal aorta. The portal vein was injected with a different colored resin in 16 cases. Digestion of soft tissues was achieved using cc. KOH solution at 60-65 °C. Extrahepatic arterial variations were classified according to Michels. All specimens underwent 3D volumetric CT reconstruction. Normal anatomy was seen in 42% of cases, and variants were seen in the other 58%. No Michels type VI or X variations were present; however, in 18% of cases the extrahepatic arterial anatomy did not fit into Michels' classification. We report four new extrahepatic arterial variations. In contrast to the available data, normal anatomy was found much less frequently, whereas the prevalence of unclassified arterial variations was higher. We detected four previously unknown variations. Our data may contribute to the reduction of complications during surgical and radiological interventions in the upper abdomen.

Automation of Pressure Control Improves Whole Porcine Heart Decellularization.

Whole heart decellularization combined with patient-specific cells may prove to be an extremely valuable approach to engineer new hearts. Mild detergents are commonly used in the decellularization process, but are known to denature and solubilize key proteins and growth factors and can therefore be destructive to the extracellular matrix (ECM) during the decellularization process. In this study, the decellularization of porcine hearts was accomplished in 24 h with only 6 h of sodium dodecyl sulfate exposure and 98% DNA removal. Automatically controlling the pressure during decellularization reduced the detergent exposure time while still completely removing immunogenic cell debris. Stimulation of macrophages was greatly reduced when comparing native tissue samples to the processed ECM. Complete cell removal was confirmed by analysis of DNA content. General collagen and elastin preservation was demonstrated. Glycosaminoglycans and collagen quantification both showed no significant differences in content after decellularization. The compression elastic modulus of the ECM after decellularization was lower than native at low strains, but there was no significant difference at high strains. Polyurethane casts of the vasculature of native and decellularized hearts demonstrated that the microvasculature network was preserved after decellularization. A static blood thrombosis assay using bovine blood was also developed. Finally, the recellularization potential of the ECM samples was demonstrated by reseeding cardiac fibroblasts and endothelial cells on the myocardium and endocardium samples.

Renal Extracellular Matrix Scaffolds From Discarded Kidneys Maintain Glomerular Morphometry and Vascular Resilience and Retains Critical Growth Factors.

BACKGROUND: Extracellular matrix (ECM) scaffolds, obtained through detergent-based decellularization of native kidneys, represent the most promising platform for investigations aiming at manufacturing kidneys for transplant purposes. We previously showed that decellularization of the human kidney yields renal ECM scaffolds (hrECMs) that maintain their basic molecular components, are cytocompatible, stimulate angiogenesis, and show an intact innate vasculature. However, evidence that the decellularization preserves glomerular morphometric characteristics, physiological parameters (pressures and resistances of the vasculature bed), and biological properties of the renal ECM, including retention of important growth factors (GFs), is still missing. METHODS: To address these issues, we studied the morphometry and resilience of hrECMs' native vasculature with resin casting at electronic microscopy and pulse-wave measurements, respectively. Moreover, we determined the fate of 40 critical GFs post decellularization with a glass chip-based multiplex enzyme-linked immunosorbent assay array and in vitro immunofluorescence. RESULTS: Our method preserves the 3-dimensional conformation of the native glomerulus. Resin casting and pulse-wave measurements, showed that hrECMs preserves the microvascular morphology and morphometry, and physiological function. Moreover, GFs including vascular endothelial growth factor and its receptors are retained within the matrices. CONCLUSIONS: Our results indicate that discarded human kidneys are a suitable source of renal scaffolds because they maintain a well-preserved structure and function of the vasculature, as well as GFs that are fundamental to achieve a satisfying recellularization of the scaffold in vivo due to their angiogenic properties.

Canine intrahepatic vasculature: is a functional anatomic model relevant to the dog?

OBJECTIVE: To clarify canine intrahepatic portal and hepatic venous system anatomy using corrosion casting and advanced imaging and to devise a novel functional anatomic model of the canine liver to investigate whether this could help guide the planning and surgical procedure of partial hepatic lobectomy and interventional radiological procedures. STUDY DESIGN: Prospective experimental study. ANIMALS: Adult Greyhound cadavers (n = 8). METHODS: Portal and hepatic vein corrosion casts of healthy livers were assessed using computed tomography (CT). RESULTS: The hepatic lobes have a consistent hilar hepatic and portal vein supply with some variation in the number of intrahepatic branches. For all specimens, 3 surgically resectable areas were identified in the left lateral lobe and 2 surgically resectable areas were identified in the right medial lobe as defined by a functional anatomic model. CONCLUSIONS: CT of detailed acrylic casts allowed complex intrahepatic vascular relationships to be investigated and compared with previous studies. Improving understanding of the intrahepatic vascular supply facilitates interpretation of advanced images in clinical patients, the planning and performance of surgical procedures, and may facilitate interventional vascular procedures, such as intravenous embolization of portosystemic shunts. Functional division of the canine liver similar to human models is possible. The left lateral and right medial lobes can be consistently divided into surgically resectable functional areas and partial lobectomies can be performed following a functional model; further study in clinically affected animals would be required to investigate the relevance of this functional model in the dog.