Search Results (10)

The azygos vein is a vessel that drains deoxygenated blood from the posterior wall of the thorax and upper abdomen into the superior vena cava. It can vary morphologically in both adults and fetuses in origin, termination, diameter, course, and tributaries, especially the hemiazygos vein and accessory hemiazygos vein, which, together with the azygos vein, form the azygos venous system. The main aim of this review is to summarize the current state of knowledge regarding the azygos vein. Another aim is to present the morphological variations of the azygos vein and their clinical significance. This information may be useful to clinicians, especially surgeons. This review also provides an overview of the embryological development of the azygos venous system and the consequences of its developmental errors, as well as their relationship to certain clinical cases and pathologies. Full article

Background/Objectives: Intracranial arteriovenous malformations (AVMs) exhibit a complex vasculature characterized by a locally occurring tangled nidus connecting the arterial and venous system bypassing the capillary network. Clinically available imaging modalities may not give sufficient spatial or temporal resolution. Adequate 3D models of large vascular areas and a detailed blood flow analysis of the nidus including the surrounding vessels are not available yet. Methods: Three representative AVM cases containing multimodal image data (3D rotational angiography, magnetic resonance angiography, magnetic resonance venography, and phase-contrast quantitative magnetic resonance imaging) are investigated. Image segmentation results in partial 3D models of the different vascular segments, which are merged into large-scale neurovascular models. Subsequently, image-based blood flow simulations are conducted based on the segmented models using patient-specific flow measurements as boundary conditions. Results: The segmentation results provide comprehensive 3D models of the overall arteriovenous morphology including realistic nidus vessels. The qualitative results of the hemodynamic simulations show realistic flow behavior in the complex vasculature. Feeding arteries exhibit increased wall shear stress (WSS) and higher flow velocities in two cases compared to contralateral vessels. In addition, feeding arteries are exposed to higher overall WSS with increased value variation between individual vessels (20.1 Pa ± 17.3 Pa) compared to the draining veins having a 62% lower WSS (8.9 Pa ± 5.9 Pa). Blood flow distribution is dragged towards the dominating circulation side feeding the nidus for all the cases quantified by the volume flow direction changes in the posterior communicating arteries. Conclusions: This multimodal study demonstrates the feasibility of the presented workflow to acquire detailed blood flow predictions in large-scale AVM models based on complex image data. The hemodynamic models serve as a base for endovascular treatment modeling influencing flow patterns in distally located vasculatures. Full article

Background: The characteristics of hemodynamic coherence in healthy states and disease remain unknown. Capillary tortuosity is a morphologic variant of microcirculatory vessels, but its effects have generally not been considered in the assessment of tissue perfusion and oxygenation. We investigated the role of sublingual capillary tortuosity in the hemodynamic coherence of anesthetized adult individuals with steady-state physiology (ASA 1) and patients with septic shock requiring emergency abdominal surgery (ASA 4E and 5E). Methods: Sublingual macro and microcirculatory variables, oxygen transport, metabolic parameters, and the capillary tortuosity score (CTS) were assessed. Results: Mean (SD) CTS was 0.55 (0.76) and 3.31 (0.86) in the steady-state and septic shock group, respectively (p < 0.001). In patients with septic shock, CTS was significantly associated with alveolar-to-arterial oxygen gradient (r = 0.658, p = 0.015) and oxygen debt (r = −0.769, p = 0.002). Significant differences were also observed in Consensus Proportion of Perfused Vessels (PPV; p < 0.001), Consensus PPV (small) (p < 0.001), Microvascular Flow Index (p < 0.001), vessel diameter (p < 0.001) and length (p < 0.001), wall shear stress (p < 0.001), lactate (p < 0.001), oxygen extraction ratio (p = 0.001), arterial oxygen content (p < 0.001), venous oxygen content (p < 0.001), oxygen delivery (p < 0.001), oxygen consumption (p < 0.001), and oxygen debt (p = 0.002) between the two groups. Conclusions: Sublingual tortuosity was essentially absent in individuals with steady-state physiology. In contrast, it was significantly increased and associated with Alveolar-to-arterial oxygen gradient and oxygen debt in critically ill patients with septic shock. Full article

Background: Despite advancements in coronary artery bypass grafting (CABG), the optimal choice of graft material remains a subject of investigation. This study aimed to comprehensively analyze the morphological characteristics of varicose veins, exploring their potential utilization in CABG compared to healthy veins. Methods: The study included 178 patients, categorized into two groups based on healthy and varicose veins. Morphological parameters, including maximum venous diameter, wall thickness, and specific changes in tunica intima (TI), tunica media (TM), and tunica adventitia (TA), were analyzed through microscopic evaluation. Results: Varicose veins exhibited a significantly larger maximum venous diameter (p = 0.0001) and increased wall thickness (p = 0.0001) compared to healthy veins. Although varicose veins showed thickening in TI and TM, the differences were not statistically significant. Notably, disorganized smooth muscle bundles were more prevalent in varicose veins (p = 0.001), suggesting potential wall weakness. The absence of vasa vasorum in TA was significantly higher in varicose veins (p = 0.050), influencing vascularization considerations. Conclusions: The comparative morphological microscopic analysis of the specimens of healthy and varicose veins reveals significant differences between the groups, which make the conclusion of this study to plead for avoiding the use of varicose veins as a graft. Full article

Background: We present a case series of Neuroendocrine Carcinoma of the Urinary Bladder (NECB) to analyse their radiologic appearance on CT, find a “Radiomic signature”, and review the current literature. Methods: 14 CT cases of NECB were reviewed and compared with a control group of 42 patients with high-grade non-neuroendocrine bladder neoplasm for the following parameters: ring enhancement; implantation site; dimensions; density; margins; central necrosis; calcifications; number of lesions; wall thickness; depth of invasion in the soft tissue; invasion of fat tissue; invasion of adjacent organs; lymph-node involvement; abdominal organ metastasis. To extract radiomic features, volumes of interest of bladder lesions were manually delineated on the portal-venous phase. The radiomic features of the two groups were identified and compared. Results: Statistical differences among NECB and control group were found in the prevalence of male sex (100% vs. 69.0%), hydronephrosis (71.4% vs. 33.3%), mean density of the mass (51.01 ± 15.48 vs. 76.27 ± 22.26 HU); product of the maximum diameters on the axial plane (38.1 ± 59.3 vs. 14.44 ± 12.98 cm2) in the control group, trigonal region involvement (78.57% vs. 19.05%). About the radiomic features, Student’s t-test showed significant correlation for the variables: “DependenceNonUniformity” (p: 0.048), “JointAverage” (p: 0.013), “LargeAreaLowGrayLevelEmphasis” (p: 0.014), “Maximum2DDiameterColumn” (p: 0.04), “Maximum 2DDiameterSlice” (p: 0.007), “MeanAbsoluteDeviation” (p: 0.021), “BoundingBoxA” (p: 0.022) and “CenterOfMassB” (p: 0.007). Conclusions: There is a typical pattern (male patient, large mass, trigonal area involvement) of NECB presentation on contrast-enhanced CT. Certain morphological characteristics and encouraging results about Radiomic features can help define the diagnosis. Full article

In microvascular head and neck reconstruction, various factors such as diabetes, alcohol consumption, and preoperative radiation hold a risk for flap loss. The primary objective of this study was to examine the vessel morphology of both recipient and donor vessels and to identify predictors for changes in the diameters of H.E.-stained specimens associated with flap loss in a prospective setting. Artery and vein samples (N = 191) were collected from patients (N = 100), with sampling from the recipient vessels in the neck area and the donor vessels prior to anastomosis. External vessel diameter transverse (ED), inner vessel diameter transverse (ID), thickness vessel intima (TI), thickness vessel media (TM), thickness vessel wall (TVW), and intima-media ratio (IMR) for the recipient (R) and transplant site (T) in arteries (A) and veins (V) were evaluated using H.E. staining. Flap loss (3%) was associated with increased ARED (<italic>p</italic> = 0.004) and ARID (<italic>p</italic> = 0.004). Preoperative radiotherapy led to a significant reduction in the outer diameter of the recipient vein in the neck (<italic>p</italic> = 0.018). Alcohol consumption (<italic>p</italic> = 0.05), previous thrombosis (<italic>p</italic> = 0.007), and diabetes (<italic>p</italic> = 0.002) were associated with an increase in the total thickness of venous recipient veins in the neck. Diabetes was also found to be associated with dilation of the venous media in the neck vessels (<italic>p</italic> = 0.007). The presence of cardiovascular disease (CVD) was associated with reduced intimal thickness (<italic>p</italic> = 0.016) and increased total venous vessel wall thickness (<italic>p</italic> = 0.017) at the transplant site. Revision surgeries were linked to increased internal and external diameters of the graft artery (<italic>p</italic> = 0.04 and <italic>p</italic> = 0.003, respectively), while patients with flap loss showed significantly increased artery diameters (<italic>p</italic> = 0.004). At the transplant site, alcohol influenced the enlargement of arm artery diameters (<italic>p</italic> = 0.03) and the intima&#x2013;media ratio in the radial forearm flap (<italic>p</italic> = 0.013). In the anterolateral thigh, CVD significantly increased the intimal thickness and the intima&#x2013;media ratio of the graft artery (<italic>p</italic> = 0.01 and <italic>p</italic> = 0.02, respectively). Patients with myocardial infarction displayed increased thickness in the <italic>A. thyroidea</italic> and artery media (<italic>p</italic> = 0.003). Facial arteries exhibited larger total vessel diameters in patients with CVD (<italic>p</italic> = 0.03), while facial arteries in patients with previous thrombosis had larger diameters and thicker media (<italic>p</italic> = 0.01). The presence of diabetes was associated with a reduced intima&#x2013;media ratio (<italic>p</italic> &lt; 0.001). Although the presence of diabetes, irradiation, and cardiovascular disease causes changes in vessel thickness in connecting vessels, these alterations did not adversely affect the overall success of the flap. Full article

Vascular graft maturation is associated with blood flow characteristics, such as velocity, pressure, vorticity, and wall shear stress (WSS). Many studies examined these factors separately. We aimed to examine the remodeling of arterio-venous fistulas (AVFs) and loop-shaped venous interposition grafts, together with 3D flow simulation. Thirty male Wistar rats were randomly and equally divided into sham-operated, AVF, and loop-shaped venous graft (Loop) groups, using the femoral and superficial inferior epigastric vessels for anastomoses. Five weeks after surgery, the vessels were removed for histological evaluation, or plastic castings were made and scanned for 3D flow simulation. Remodeling of AVF and looped grafts was complete in 5 weeks. Histology showed heterogeneous morphology depending on the distribution of intraluminal pressure and WSS. In the Loop group, an asymmetrical WSS distribution coincided with the intima hyperplasia spots. The tunica media was enlarged only when both pressure and WSS were high. The 3D flow simulation correlated with the histological findings, identifying “hotspots” for intimal hyperplasia formation, suggesting a predictive value. These observations can be useful for microvascular research and for quality control in microsurgical training. Full article

The internal vertebral venous plexus (IVVP) is a thin-walled, valveless venous network that is located inside the vertebral canal, communicating with the cerebral venous sinuses. The objective of this study was to perform a morphometric analysis of the IVVP, dural sac, epidural space and vertebral canal between the L1 and L7 vertebrae with contrast-enhanced computed tomography (CT). Six clinically healthy adult dogs weighing between 12 kg to 28 kg were used in the study. The CT venographic protocol consisted of a manual injection of 880 mgI/kg of contrast agent (587 mgI/kg in a bolus and 293 mgI/mL by continuous infusion). In all CT images, the dimensions of the IVVP, dural sac, and vertebral canal were collected. Dorsal reconstruction CT images showed a continuous rhomboidal morphological pattern for the IVVP. The dural sac was observed as a rounded isodense structure throughout the vertebral canal. The average area of the IVVP ranged from 0.61 to 0.74 mm² between L1 and L7 vertebrae (6.3–8.9% of the vertebral canal), and the area of the dural sac was between 1.22 and 7.42 mm² (13.8–72.2% of the vertebral canal). The area of the epidural space between L1 and L7 ranged from 2.85 to 7.78 mm² (27.8–86.2% of the vertebral canal). This CT venography protocol is a safe method that allows adequate visualization and morphometric evaluation of the IVVP and adjacent structures. Full article

Sclerotherapy is the chemical occlusion of vessels using an intravenous injection of a liquid or foamed sclerosing agent that is used in the therapy of blood and lymphatic vessels malformations in the young, and for spider veins, smaller varicose veins, hemorrhoids and hydroceles in adults. This study aimed to assess the effectiveness of mechanosclerotherapy of venous veins with a new device—Flebogrif^®—based on an animal model. The experiment was performed on nine Polish Merino sheep weighing 40–50 kilograms. The animals were anesthetized intravenously. The material was divided into three groups: two experimental (1 and 2) and control (3) group. The first experimental group was treated with the use of Flebogrif^® and a sclerosant simultaneously, while only Flebogrif^® was used in the second experimental group. Flebogrif^® was applied into the lateral saphenous vein of both pelvic limbs. The vessel wall thickness was estimated at four points of the histological image in mm (V1, V2, V3, V4). For one month, the animals were euthanized, and the occlusion rate of the treated veins and changes in the vein wall were determined. Histological slides were analyzed under a light microscope and histometry of the vein wall was performed. The Shapiro–Wilk test and the quantity of the investigated parameter groups allowed for using a non-parametric method at four points to compare thickness measurements (the Mann–Whitney test), with p < 0.05. The Mann–Whitney test indicated statistically significant differences between both experimental groups. The results obtained from morphometrical and histological analysis showed better results in the first experimental group than those of the second experimental group. Finally, statistical analysis revealed significant differences between the both the experimental group and control group in morphological analysis. The achieved results allowed us to conclude that the simultaneous use of Flebogrif^® and a sclerosant yielded better results of vein lumen reduction than the use of Flebogrif^® alone. Full article

(1) Background: Chronic venous insufficiency (CVI) is a common disorder related to functional and morphological abnormalities of the venous system. Inflammatory processes and angiogenesis alterations greatly concur to the onset of varicose vein. KYP-2047 is a selective inhibitor of prolyl oligopeptidase (POP), a serine protease involved in the release of pro-angiogenic molecules. The aim of the present study is to evaluate the capacity of KYP-2047 to influence the angiogenic and inflammatory mechanisms involved in the pathophysiology of CVI. (2) Methods: An in vivo model of CVI-induced by saphene vein ligation (SVL) and a tissue block culture study were performed. Mice were subjected to SVL followed by KYP-2047 treatment (intraperitoneal, 10 mg/kg) for 7 days. Histological analysis, Masson’s trichrome, Van Gieson staining, and mast cells evaluation were performed. Release of cytokines, nitric oxide synthase production, TGF-beta, VEGF, α-smooth muscle actin, PREP, Endoglin, and IL-8 quantification were investigated. (3) Results: KYP-2047 treatment ameliorated the histological abnormalities of the venous wall, reduced the collagen increase and modulated elastin content, lowered cytokines levels and prevented mast degranulation. Moreover, a decreased expression of TGF-beta, eNOS, VEGF, α-smooth muscle actin, IL-8, and PREP was observed in in vivo study; also a reduction in VEGF and Endoglin expression was confirmed in tissue block culture study. (4) Conclusions: For the first time, this research, highlighting the importance of POP as new target for vascular disorders, revealed the therapeutic potential of KYP-2047 as a helpful treatment for the management of CVI. Full article