Branch Vessels Research Articles

Assessing boundary conditions in CFD for transvalvular pressure gradient calculation in cardiac hemodynamics

Abstract Background Computational fluid dynamics (CFD), which has the advantages of providing detailed pressure distribution, has been widely used for cardiac function assessment and heart disease diagnosis. However, the results are usually influenced by the boundary conditions. Particularly, the transvalvular pressure gradient, which serves as a crucial indicator for mitral stenosis and the efficacy of mitral valve surgery, can easily be miscalculated. Here, we assess the effects of widely used boundary conditions on the transvalvular pressure gradient computed based on the Bernoulli equation and the line probe, respectively. Purpose This study aims to determine the effects of boundary conditions on the transvalvular pressure gradient in CFD. Methods We constructed cardiac models including left atrium, left ventricle, aorta from CT and mitral valve from transesophageal echocardiography data (Figure 1). The intraventricular flow fields were computed using CFD tool with four different boundary conditions (BC) at the same cardiac output. BC1 involved specifying the total flow rate of the aorta, with zero pressure at the entrance of the pulmonary veins. BC2 maintained equal flow rates at the entrances of the pulmonary veins. BC3 followed Murray's law, where the flow rate ratio in the pulmonary veins is proportional to the 1.5 power of the area ratio. BC4 followed Poiseuille's law, where the flow rate ratio is proportional to the square of the area ratio. The results encompassed the mean transvalvular pressure gradient and peak transvalvular pressure gradient obtained through the Bernoulli equation and the line probe methods, respectively. Results Figures 2(A-D) present the contours of transvalvular pressure under peak flow velocity conditions and the isosurfaces of vorticity within the ventricle. The results show that the pressure within the atrium is notably lower in the BC2, leading to a 63% underestimation in the mean transvalvular pressure gradient and a 22.9% deviation in the peak transvalvular pressure gradient (Figure 2 F). The transvalvular pressure gradient for BC1, BC3, and BC4 do not exceed 10%. The results reveal that the pressure distribution and vorticity within the ventricle are consistent, primarily due to the influence of the mitral valve. Conclusion When evaluating transvalvular pressure gradient using CFD, it is crucial to specify appropriate boundary conditions. Using inappropriate boundary conditions may lead to underestimation of the transvalvular pressure gradient, thereby affecting further diagnostic decisions. In research studies, it is recommended to allocate flow in different branch vessels according to Murray's law, where the flow in different branch vessels is proportional to the 1.5 power of the vessel cross-sectional area.Modelling flow chartTransvalvular pressure gradient

Side branch preservation using tip detection-antegrade dissection reentry after failed subintimal tracking and reentry in chronic total occlusion: a case report

Abstract Background Techniques for treating difficult chronic total occlusions (CTO) have evolved with the discovery of the tip detection-antegrade dissection reentry (TDADR) guided by intravascular ultrasound (IVUS). This case demonstrates TDADR as a viable bailout in failed subintimal tracking and reentry (STAR) technique. Case Summary A 78-year-old man with stable angina on optimal medical therapy had exertional angina pectoris secondary to a residual CTO lesion of the left circumflex coronary (LCX) artery. PCI was performed for a mid-LCX CTO with a blunt proximal stump where the dissection plane expanded along the main vessel and side branch 2. Due to lack of promising collaterals for the retrograde approach, STAR successfully recanalized side branch 1. As main vessel failed to be recanalized, we proceeded with an AnteOwl IVUS-guided TDADR, intending guidewire penetration into the true lumen from the middle of the dissection plane at the main vessel, proximal to side branch 2 origin. Accurate wiring was achieved, and a guidewire was placed on side branch 2 for protection. After stent placement in the main vessel and kissing inflation, cutting balloon dilatation was performed to create reentries for the STAR-induced extended main vessel hematoma. The procedure resulted in complete revascularization of main vessel and side branches. At 12-month follow-up, no further angina was reported, and coronary computed tomography (CT) showed patent side branches with no significant in-stent restenosis. Discussion Imaging-based TDADR method was effective in our present case despite failed subintimal tracking and reentry technique. Limited IVUS and operator availability may become a barrier in implementing TDADR.

Simulation and Experimental Study on Heat Transfer Performance of Bionic Structure-Based Battery Liquid Cooling Plate

This study presents a bionic structure-based liquid cooling plate designed to address the heat generation characteristics of prismatic lithium-ion batteries. The size of the lithium-ion battery is 148 mm × 26 mm × 97 mm, the positive pole size is 20 mm × 20 mm × 3 mm, and the negative pole size is 22 mm × 20 mm × 3 mm. Experimental testing of the Li-ion battery’s heat generation model parameters, in conjunction with bionic structure and micro-channel features, has led to the development of this innovative cooling system. The traditional bionic liquid cooling plate’s structure is often singular; however, the flow path of the liquid cooling plate designed in this paper is based on the combination of the distribution of human blood vessel branches and the structure of insect wing veins. The external dimension of the liquid cooling plate is 152 mm × 100 mm × 6 mm (length × width × height). Utilizing numerical simulation and thermodynamic principles, we analyzed the heat transfer efficacy of the bionic liquid cooling module for power batteries. Specifically, we investigated the impact of varying coolant flow rates and the contact radius between flow channels on the thermal performance of the bionic battery modules. Our findings indicate that a liquid flow rate of 0.6 m/s achieves a stable maximum surface temperature and temperature differential across the bionic battery liquid cooling module, with a relatively low overall system power consumption, suggesting room for further enhancement of heat transfer performance. By augmenting the contact radius between flow channels, we observed an initial increase in the maximum surface temperature, temperature differential, and inlet–outlet pressure differential at a flow rate of 0.2 m/s. However, at flow rates equal to or exceeding 0.4 m/s, these parameters stabilized across different design Scenarios. Notably, the pump power consumption remained consistent across various scenarios and flow rates. This study’s outcomes offer valuable insights for the development of liquid-cooled battery thermal management systems that are energy-efficient and offer superior heat transfer capabilities.

A flexible generative algorithm for growing in silico placentas.

The placenta is crucial for a successful pregnancy, facilitating oxygen exchange and nutrient transport between mother and fetus. Complications like fetal growth restriction and pre-eclampsia are linked to placental vascular structure abnormalities, highlighting the need for early detection of placental health issues. Computational modelling offers insights into how vascular architecture correlates with flow and oxygenation in both healthy and dysfunctional placentas. These models use synthetic networks to represent the multiscale feto-placental vasculature, but current methods lack direct control over key morphological parameters like branching angles, essential for predicting placental dysfunction. We introduce a novel generative algorithm for creating in silico placentas, allowing user-controlled customisation of feto-placental vasculatures, both as individual components (placental shape, chorionic vessels, placentone) and as a complete structure. The algorithm is physiologically underpinned, following branching laws (i.e. Murray's Law), and is defined by four key morphometric statistics: vessel diameter, vessel length, branching angle and asymmetry. Our algorithm produces structures consistent with in vivo measurements and ex vivo observations. Our sensitivity analysis highlights how vessel length variations and branching angles play a pivotal role in defining the architecture of the placental vascular network. Moreover, our approach is stochastic in nature, yielding vascular structures with different topological metrics when imposing the same input settings. Unlike previous volume-filling algorithms, our approach allows direct control over key morphological parameters, generating vascular structures that closely resemble real vascular densities and allowing for the investigation of the impact of morphological parameters on placental function in upcoming studies.

Operative Times and Outcomes of Complex Endovascular Repairs of Thoracoabdominal Aneurysms

IntroductionOwing to the significant morbidity and mortality of open thoracoabdominal aortic aneurysm surgery, complex endovascular repairs (eTAAA) have become increasingly common, but still carry substantial risk. These repairs require large bore access, with resultant pelvic and lower extremity ischemia. We therefore hypothesized that operative timing would be associated with outcomes, as efficient surgery would limit the ischemic time as well as anesthesia time. MethodsWe studied all eTAAA repairs (Crawford Types 1-3, 5) incorporating at least one branch vessel from 2014 to 2021 in the Vascular Quality Initiative, and categorized them into quartiles of total operating time. To account for variations in case complexity and intraoperative events, we performed a sub-analysis stratifying each surgeon by their median operating time. Multilevel logistic regression was employed to compare perioperative outcomes including mortality, thoracoabdominal life altering events (TALE:composite of perioperative death, stroke, permanent paralysis and/or dialysis), spinal cord ischemia (SCI), acute kidney injury (AKI), major adverse cardiac events (MACE), myocardial infarction, and dialysis. ResultsThere were 2,925 eTAAA repairs during the study period. Procedure times ranged from <204 minutes in the first quartile to >365 minutes in the fourth. Longer cases more commonly involved older patients who were more often female, and higher rates of prior stroke, and preoperative anemia. They involved larger, more extensive aneurysms, with higher rates of prior aortic surgery, and more commonly employed PMEGs or parallel grafting to incorporate more branch vessels. In addition, they were less often staged procedures, and used more spinal drains, femoral cutdowns, and upper extremity access. Operating time decreased as experience increased. In adjusted analyses, the odds of mortality and every morbidity studied increased stepwise with operating time, with 4 to 13-fold higher odds in the highest quartiles. Spinal cord ischemia had the strongest association with procedure times, with seven-fold higher odds (OR 7.2 [2.9-17.9], P<.001) of any SCI in the highest quartile compared to the lowest, and 13-fold higher odds of permanent SCI (OR 13.1 [3.9-44.7], P<.001). These results were consistent when surgeons were grouped into quartiles by their median operating times. Medium-term mortality was also higher in the upper quartile of operating time (HR 2.7 [1.4-5.1], P=.002). ConclusionLonger operating times for complex eTAAA repairs were associated with markedly higher rates of morbidity and mortality, especially spinal cord ischemia. These results emphasize the importance of expeditious repairs by experienced teams.

Laparoscopic Transabdominal Needle-free Emergency Cerclage in the Early Second Trimester of Pregnancy after Failed Transvaginal Cerclage: Two Case Reports and a Review of the Literature.

The aim of the study was to describe the preventive option and safety of laparoscopic transabdominal emergency cerclage in pregnant women with advanced cervical shortening after failed vaginal cerclage or in whom vaginal cerclage is no longer possible. Laparoscopic isthmo-cervical emergency cerclage was carried out in two patients at 13+0 and 15+5 weeks of gestation (GW) respectively. Both patients had cervical shortening and it was no longer possible to expose the cervix after conization or re-conization. The attempts to carry out transvaginal cerclage were unsuccessful. The technical aspects, feasibility, safety, and pregnancy outcomes after laparoscopic transabdominal cerclage are presented here, based on two case reports. The cerclages were placed after blunt dissection of the uterine vessels and careful introduction of a KELLY forceps through the avascular space between the ascending and descending branches of the uterine vessels without using a needle. The operating times were 93 and 134 minutes (min), respectively. The estimated blood loss during the procedure was less than 50ml and neither perioperative nor postoperative complications occurred. The subsequent course of both pregnancies was uneventful and fetal development in both cases was normal. In the first case, the baby was delivered by secondary cesarean section following premature rupture of membranes in week 35+4 of gestation. The baby had a birthweight of 2786g, APGAR scores of 8/9/10 and an umbilical cord arterial pH of 7.36. In the second case, delivery was by primary cesarean section in week 39+5 of gestation. The infant had a birth weight of 4160g, APGAR scores of 5/9/10 and an umbilical cord arterial pH of 7.20. Laparoscopic transabdominal cerclage is a safe and effective treatment option, even early in the second trimester of pregnancy, for patients in whom transvaginal cerclage is no longer possible due to anatomical factors. The method is technically very feasible and is associated with positive obstetric outcomes. The overall risk of perioperative complications is within acceptable limits.

Incidentally detected noninfectious thoracic aortitis: A clinical approach.

Noninfectious aortitis is occasionally detected incidentally, either on imaging or on histopathologic review after open thoracic aortic surgery. It can present as a clinically asymptomatic, seemingly focal lesion, as diffuse inflammation throughout several aortic segments but sparing the branch vessels, or as a manifestation of a widespread systemic condition. Treatment differs based on etiology, so once identified, all patients with aortitis need a thorough evaluation, laboratory tests, complete large-vessel imaging, and a referral to a vasculitis expert. All patients with aortitis are at high risk of future vascular complications and should be followed with serial clinical evaluations and imaging.

Vascular Biomarkers for Pulmonary Nodule Malignancy: Arteries vs. Veins.

This study aims to investigate the association between the arteries and veins surrounding a pulmonary nodule and its malignancy. A dataset of 146 subjects from a LDCT lung cancer screening program was used in this study. AI algorithms were used to automatically segment and quantify nodules and their surrounding macro-vasculature. The macro-vasculature was differentiated into arteries and veins. Vessel branch count, volume, and tortuosity were quantified for arteries and veins at different distances from the nodule surface. Univariate and multivariate logistic regression (LR) analyses were performed, with a special emphasis on the nodules with diameters ranging from 8 to 20 mm. ROC-AUC was used to assess the performance based on the k-fold cross-validation method. Average feature importance was evaluated in several machine learning models. The LR models using macro-vasculature features achieved an AUC of 0.78 (95% CI: 0.71-0.86) for all nodules and an AUC of 0.67 (95% CI: 0.54-0.80) for nodules between 8-20 mm. Models including macro-vasculature features, demographics, and CT-derived nodule features yielded an AUC of 0.91 (95% CI: 0.87-0.96) for all nodules and an AUC of 0.82 (95% CI: 0.71-0.92) for nodules between 8-20 mm. In terms of feature importance, arteries within 5.0 mm from the nodule surface were the highest-ranked among macro-vasculature features and retained their significance even with the inclusion of demographics and CT-derived nodule features. Arteries within 5.0 mm from the nodule surface emerged as a potential biomarker for effectively discriminating between malignant and benign nodules.

Modeling Hemodynamics in Three-Dimensional, Biomimetic, Branched, Microfluidic, Vascular Networks.

Neovascularization has been extensively studied because of its significant role in both physiological processes and diseases. The significance of vascular microfluidic platforms lies in its essential role in recreating an in vitro environment capable of supporting cellular and tissue systems through the process of neovascularization. Biomechanical properties in a tissue engineered system use fluid flow and transport properties to recapitulate physiological systems. This enables mimicry of organ systems which can further personalized and regenerative medicine. Thus, fluid hemodynamics can be used to study these flow patterns and create a system that mimics real physiological pathways and processes. The establishment of stable flow pathways encourages endothelial cells (ECs) ECs to undergo neovascularization. Specifically, the shear stress applied in capillary beds generates the increased proliferation and differentiation of ECs to build larger microcirculatory beds. Here, we describe a mathematical model that uses branching patterns and vessel morphology to predict hemodynamic parameters in capillary beds. A retinal capillary bed is used as one-use case of our model to show how the mathematical framework can be used to determine hemodynamic parameters for any microfluidic system. In doing so, this tool can be altered to be used to supplement emerging research areas in neovascularization.

Retinal Imaging-Based Oculomics: Artificial Intelligence as a Tool in the Diagnosis of Cardiovascular and Metabolic Diseases.

Cardiovascular diseases (CVDs) are a major cause of mortality globally, emphasizing the need for early detection and effective risk assessment to improve patient outcomes. Advances in oculomics, which utilize the relationship between retinal microvascular changes and systemic vascular health, offer a promising non-invasive approach to assessing CVD risk. Retinal fundus imaging and optical coherence tomography/angiography (OCT/OCTA) provides critical information for early diagnosis, with retinal vascular parameters such as vessel caliber, tortuosity, and branching patterns identified as key biomarkers. Given the large volume of data generated during routine eye exams, there is a growing need for automated tools to aid in diagnosis and risk prediction. The study demonstrates that AI-driven analysis of retinal images can accurately predict cardiovascular risk factors, cardiovascular events, and metabolic diseases, surpassing traditional diagnostic methods in some cases. These models achieved area under the curve (AUC) values ranging from 0.71 to 0.87, sensitivity between 71% and 89%, and specificity between 40% and 70%, surpassing traditional diagnostic methods in some cases. This approach highlights the potential of retinal imaging as a key component in personalized medicine, enabling more precise risk assessment and earlier intervention. It not only aids in detecting vascular abnormalities that may precede cardiovascular events but also offers a scalable, non-invasive, and cost-effective solution for widespread screening. However, the article also emphasizes the need for further research to standardize imaging protocols and validate the clinical utility of these biomarkers across different populations. By integrating oculomics into routine clinical practice, healthcare providers could significantly enhance early detection and management of systemic diseases, ultimately improving patient outcomes. Fundus image analysis thus represents a valuable tool in the future of precision medicine and cardiovascular health management.

Analysis and comparison of retinal vascular parameters under different glucose metabolic status based on deep learning.

To develop a deep learning-based model for automatic retinal vascular segmentation, analyzing and comparing parameters under diverse glucose metabolic status (normal, prediabetes, diabetes) and to assess the potential of artificial intelligence (AI) in image segmentation and retinal vascular parameters for predicting prediabetes and diabetes. Retinal fundus photos from 200 normal individuals, 200 prediabetic patients, and 200 diabetic patients (600 eyes in total) were used. The U-Net network served as the foundational architecture for retinal artery-vein segmentation. An automatic segmentation and evaluation system for retinal vascular parameters was trained, encompassing 26 parameters. Significant differences were found in retinal vascular parameters across normal, prediabetes, and diabetes groups, including artery diameter (P=0.008), fractal dimension (P=0.000), vein curvature (P=0.003), C-zone artery branching vessel count (P=0.049), C-zone vein branching vessel count (P=0.041), artery branching angle (P=0.005), vein branching angle (P=0.001), artery angle asymmetry degree (P=0.003), vessel length density (P=0.000), and vessel area density (P=0.000), totaling 10 parameters. The deep learning-based model facilitates retinal vascular parameter identification and quantification, revealing significant differences. These parameters exhibit potential as biomarkers for prediabetes and diabetes.

A Hessian-Based Deep Learning Preprocessing Method for Coronary Angiography Image Analysis

Leveraging its high accuracy and stability, deep-learning-based coronary artery detection technology has been extensively utilized in diagnosing coronary artery diseases. However, traditional algorithms for localizing coronary stenosis often fall short when detecting stenosis in branch vessels, which can pose significant health risks due to factors like imaging angles and uneven contrast agent distribution. To tackle these challenges, we propose a preprocessing method that integrates Hessian-based vascular enhancement and image fusion as prerequisites for deep learning. This approach enhances fuzzy features in coronary angiography images, thereby increasing the neural network’s sensitivity to stenosis characteristics. We assessed the effectiveness of this method using the latest deep learning networks, such as YOLOv10, YOLOv9, and RT-DETR, across various evaluation metrics. Our results show that our method improves AP50 accuracy by 4.84% and 5.07% on RT-DETR R101 and YOLOv10-X, respectively, compared to images without special pre-processing. Furthermore, our analysis of different imaging angles on stenosis localization detection indicates that the left coronary artery zero is the most suitable for detecting stenosis with a AP50(%) value of 90.5. The experimental results have revealed that the proposed method is effective as a preprocessing technique for deep-learning-based coronary angiography image processing and enhances the model’s ability to identify stenosis in small blood vessels.

Edge morphology attention mechanism and optimal geometric matching connection model for vascular segmentation

Over the past decades, medical image segmentation methods have been intensively developed, but there are still a number of unsolved challenging problems in vascular image segmentation, including broken vessels, insufficient vessel branches, and missing small vessels. In order to optimize the topology and accuracy of segmented vessels, we propose a novel Edge Morphology Attention Network (EMA-Net) for the segmentation of vessel-like structures, and an Optimal Geometric Matching Connection (OGMC) model to connect the broken vessel fragments. The EMA-Net has an edge attention module that is able to improve segmented performances of edges and small branches by morphology operation extracting boundary voxels on multi-scales. The OGMC model uses the geometry concept of curve touching to filter out fragmented vessel endpoints, and then employs minimal surfaces to determine the optimal connection order between blood vessels. Finally, we adopt geodesics to repair missing vessels under a Riemannian metric. Our method achieves superior or competitive results compared to state-of-the-art methods on four datasets of 3D vascular segmentation tasks, both effectively reducing vessel broken and increasing vessel branch richness, yielding blood vessels with more precise topological structures.

Embedding Biomimetic Vascular Networks via Coaxial Sacrificial Writing into Functional Tissue.

Printing human tissues and organs replete with biomimetic vascular networks is of growing interest. While it is possible to embed perfusable channels within acellular and densely cellular matrices, they do not currently possess the biomimetic architectures found in native vessels. Here, coaxialsacrificial writing into functional tissues (co-SWIFT) is developed, an embedded bioprinting method capable of generating hierarchically branching, multilayered vascular networks within both granular hydrogel and densely cellular matrices. Coaxial printheads are designed with an extended core-shell configuration to facilitate robust core-core and shell-shell interconnections between printed branching vessels during embedded bioprinting. Using optimized core-shell ink combinations, biomimetic vessels composed of a smooth muscle cell-laden shell that surrounds perfusable lumens are coaxially printed into granular matrices composed of: 1) transparent alginate microparticles, 2) sacrificial microparticle-laden collagen, or 3) cardiac spheroids derived from human induced pluripotent stem cells. Biomimetic blood vessels that exhibit good barrier function are produced by seeding these interconnected lumens with a confluent layer of endothelial cells. Importantly, it is found that co-SWIFT cardiac tissues mature under perfusion, beat synchronously, and exhibit a cardio-effective drug response in vitro. This advance opens new avenues for the scalable biomanufacturing of vascularized organ-specific tissues for drug testing, disease modeling, and therapeutic use.

Repeating ultrastructural motifs provide insight into the organization of the octopus arm nervous system

The peripheral nervous system of the octopus is among the most complex of any animal. In each arm, hundreds of serial ganglia form a central core of nervous tissue processing sensory input, issuing motor commands, and exchanging information with the central brain.1,2,3,4,5 In addition to the central cord, there are two other types of neural elements: fine intramuscular nerve cords (INCs)6,7 and small sucker ganglia at the base of each sucker.2,6,8,9 Connections between these different elements and the structural organization of the arm nervous system remain poorly understood, despite decades of interest and a more recent explosion of studies of the cephalopod nervous system.8,10,11,12,13,14,15 Here, we use serial blockface electron microscopy to reconstruct large volumes of an arm from Octopus bocki at the base and toward the tip, mapping connections between the various neural elements and their relationship to the muscle and skin. We show that the ganglia follow an alternating mirror-image pattern along the arm, where the left or right-sided location of successive suckers determines ganglionic orientation. We also describe previously unrecognized patterns in (1) continuity of oblique connectives between the INCs that encircle the arm; (2) repeatable structures of the major blood vessel branches and nerve connectives within each ganglion; (3) clustering of rare, unusually large neurons within the cell body layers; and (4) division of the cortex into repeating columns. These new findings from the first 3DEM reconstruction of the arm should greatly facilitate future studies of octopus neurobiology, particularly sensori-motor integration and arm control.

Advanced visualization of aortic dissection anatomy and hemodynamics

Aortic dissection is a life-threatening cardiovascular disease constituted by the delamination of the aortic wall. Due to the weakened structure of the false lumen, the aorta often dilates over time, which can – after certain diameter thresholds are reached – increase the risk of fatal aortic rupture. The identification of patients with a high risk of late adverse events is an ongoing clinical challenge, further complicated by the complex dissection anatomy and the wide variety among patients. Moreover, patient-specific risk stratification depends not only on morphological, but also on hemodynamic factors, which can be derived from computer simulations or 4D flow magnetic resonance imaging (MRI). However, comprehensible visualizations that depict the complex anatomical and functional information in a single view are yet to be developed. These visualization tools will assist clinical research and decision-making by facilitating a comprehensive understanding of the aortic state. For that purpose, we identified several visualization tasks and requirements in close collaboration with cardiovascular imaging scientists and radiologists. We displayed true and false lumen hemodynamics using pathlines as well as surface hemodynamics on the dissection flap and the inner vessel wall. Pathlines indicate antegrade and retrograde flow, blood flow through fenestrations, and branch vessel supply. Dissection-specific hemodynamic measures, such as interluminal pressure difference and flap compliance, provide further insight of the blood flow throughout the cardiac cycle. Finally, we evaluated our visualization techniques with cardiothoracic and vascular surgeons in two separate virtual sessions.

Exploring the potential of two Pseudomonas species to produce vincristine from vinblastine via biotransformation

A biotransformation pair consisting of vinblastine: vincristine present in the Catharanthus roseus plant is of immense pharmacological significance. In this study, we successfully transformed vinblastine into vincristine outside the plant using Pseudomonas aeruginosa 8485 and Pseudomonas fluorescens 2421 and evaluated the antiangiogenic potential of thus produced vincristine through the CAM assay. The toxicity assay showed that both Pseudomonas spp. can tolerate varying concentrations (25–100 µl of 1 mg/ml) of vinblastine. The biotransformation was performed in a liquid nutrient broth medium containing vinblastine (25–100 µl), and Pseudomonas spp. inoculums (50–150 µl) by incubating at 30 °C and 37 °C, respectively for 8 days. The process was optimized for substrate and culture concentrations, pH, temperature, and rotation speed (rpm) for the highest conversion. Analysis using LC–MS/MS confirmed the presence of vincristine as a product of the vinblastine biotransformation by two Pseudomonas spp. P. fluorescens 2421 showed a faster conversion rate with 95% of vinblastine transformed within 24 h than P. aeruginosa 8485, which demonstrated a conversion rate of 92% on the 8th day. From LC–MS/MS analysis, the optimal conditions for the reaction were determined as vinblastine (25 µl), microbial inoculums (150 µl or 200 × 106 and 210 × 106 CFU/ml), pH 7.4, rotation speed of 180 rpm, and temperatures of 30 °C and 37 °C with incubation time of 8 days. The vincristine produced exhibited potent antiangiogenic activity in the CAM assay reducing the thickness and branching of blood vessels in a dose-dependent manner. The study concludes that both Pseudomonas spp. showed promise for vincristine production from vinblastine, without compromising its antiangiogenic properties.

Scalp Reconstruction With Free Tissue Transfer Using Descending Branch of Lateral Circumflex Femoral Vessels as Interposition Graft.

Despite the rich blood supply to the scalp, postoperative skin necrosis at the surgical site sometimes occurs, and unresolved defects often present a significant challenge for the surgeon. When planning a free flap for scalp reconstruction, distant anastomoses may be necessary if local recipient vessels are unavailable due to previous surgery. This study presents the authors' treatment strategy, which includes extending the pedicle length with arteriovenous bundle interposition grafts. Two patients who experienced surgical wound necrosis after bypass surgery for moyamoya disease underwent reconstruction for skin and soft tissue coverage. To evaluate the altered anatomical structures after the previous surgery, three-dimensional computed tomography angiography was performed, and preoperative photos were taken to accurately measure the expected defect. The surgical strategy was designed to accommodate their unique conditions, utilizing an arteriovenous interposition graft, which included 2 stages of microvascular anastomoses, for pedicle lengthening. The procedure successfully bridged the gap between distant recipient vessels and the extensive defect, and the wounds healed without major complications such as venous congestion or total flap loss. Both patients were satisfied with the surgical outcomes. Arteriovenous bundle interposition grafts can be a useful option for patients with complex scalp defects who lack local recipient vessels. The use of an anterolateral thigh flap with artery-to-artery anastomosis, utilizing the lateral circumflex femoral artery from the opposite side in this study, offers many advantages compared with traditional pedicle lengthening tools utilizing vein-to-artery anastomosis.

Lymphatic endothelial cell-specific NRAS p.Q61R mutant embryos show abnormal lymphatic vessel morphogenesis.

Generalized lymphatic anomaly (GLA) and kaposiform lymphangiomatosis (KLA) are rare congenital disorders that arise through anomalous embryogenesis of the lymphatic system. A somatic activating NRAS p.Q61R variant has been recently detected in GLA and KLA tissues, suggesting that the NRAS p.Q61R variant plays an important role in the development of these diseases. To address this role, we studied the effect of the NRAS p.Q61R variant in lymphatic endothelial cells (LECs) on the structure of the lymphatics during embryonic and postnatal lymphangiogenesis applying inducible, LEC-specific NRAS p.Q61R variant in mice. Lox-stop-Lox NrasQ61R mice were crossed with Prox1-CreERT2 mice expressing tamoxifen-inducible Cre recombinase specifically in LECs. Whole-mount immunostaining of embryonic back skin using an antibody against the LEC surface marker VEGFR3 showed considerably greater lymphatic vessel width in LEC-specific NRAS p.Q61R mutant embryos than in littermate controls. These mutant embryos also showed a significant reduction in the number of lymphatic vessel branches. Furthermore, immunofluorescence staining of whole-mount embryonic back skin using an antibody against the LEC-specific nuclear marker Prox1 showed a large increase in the number of LECs in LEC-specific NRAS p.Q61R mutants. In contrast, postnatal induction of the NRAS p.Q61R variant in LECs did not cause abnormal lymphatic vessel morphogenesis. These results suggest that the NRAS p.Q61R variant in LECs plays a role in development of lymphatic anomalies. While this model does not directly reflect the human pathology of GLA and KLA, there are overlapping features, suggesting that further study of this model may help in studying GLA and KLA mechanisms.

Clinical observation of three-dimensional reconstruction in thoracoscopic segmental pneumonectomy.

Accurately identifying the branches of pulmonary segmental vessels and bronchi, as well as adjacent structures, and determining the spatial location of lesions within pulmonary segments, are major challenges for thoracic surgeons. The application of three-dimensional reconstruction technology holds promise in addressing this issue. To evaluate the clinical value of three-dimensional reconstruction in thoracoscopic segmental surgery. Seventy-seven patients who underwent thoracoscopic segmental surgery combined with three-dimensional reconstruction at our hospital from January 1, 2020, to August 31, 2023, were retrospectively analyzed. Preoperative chest enhanced CT scans were conducted, and MIMICS software aided in reconstructing DICOM format original data for patients with pulmonary nodules to facilitate intraoperative nodule localization. Accurate segmental pneumonectomy was performed by comparing preoperative anatomical identification of target segmental arteries, veins, and bronchi, with surgical details and postoperative outcomes recorded, including intraoperative pulmonary resection distribution, operation time, blood loss, chest tube drainage, extubation time, hospital stay, and complications. Following preoperative three-dimensional reconstruction, successful segmental lung surgeries were performed, predominantly with single segmental resection (92.2%), and a minority with combined segmentectomy (7.8%). Median operation time was 130225 minutes, with intraoperative blood loss at 70100 mL and postoperative chest tube drainage at 347 mL (159690mL). Median extubation time and hospital stay were 4 days and 7 days, respectively. Complications within the 3-month follow-up affected 11.7% of cases, including persistent pulmonary leakage (7.1%), pulmonary infection (4.3%), atelectasis (4.3%), and pleural effusion (1.4%), with no fatalities. Preoperative 3D reconstruction can help the operator to perform safe, efficient and accurate thoracoscopic segmental pneumonectomy, which is worth popularizing in clinic.