Vascular Structures Research Articles

Unlocking the tumor-immune microenvironment in osteosarcoma: insights into the immune landscape and mechanisms.

Osteosarcoma has a unique tumor microenvironment (TME), which is characterized as a complex microenvironment comprising of bone cells, immune cells, stromal cells, and heterogeneous vascular structures. These elements are intricately embedded in a mineralized extracellular matrix, setting it apart from other primary TMEs. In a state of normal physiological function, these cell types collaborate in a coordinated manner to maintain the homeostasis of the bone and hematopoietic systems. However, in the pathological condition, i.e., neoplastic malignancies, the tumor-immune microenvironment (TIME) has been shown to promote cancer cells proliferation, migration, apoptosis and drug resistance, as well as immune escape. The intricate and dynamic system of the TIME in osteosarcoma involves crucial roles played by various infiltrating cells, the complement system, and exosomes. This complexity is closely associated with tumor cells evading immune surveillance, experiencing uncontrolled proliferation, and facilitating metastasis. In this review, we elucidate the intricate interplay between diverse cell populations in the osteosarcoma TIME, each contributing uniquely to tumor progression. From chondroblastic and osteoblastic osteosarcoma cells to osteoclasts, stromal cells, and various myeloid and lymphoid cell subsets, the comprehensive single-cell analysis provides a detailed roadmap of the complex osteosarcoma ecosystem. Furthermore, we summarize the mutations, epigenetic mechanisms, and extracellular vesicles that dictate the immunologic landscape and modulate the TIME of osteosarcoma. The perspectives of the clinical implementation of immunotherapy and therapeutic approaches for targeting immune cells are also intensively discussed.

A novel m-xylylene-diamine/glucose based-supramolecular eutectogels with tissue clearing for three dimensional histological imaging

Hydrogel-based tissue clearing technologies have shown significant promise for deep-tissue imaging and subcellular-level optical 3D reconstruction of whole organs. This study proposes a novel approach utilizing a deep eutectic solvent (DES) formulated with glucose and m-xylylene-diamine (MXDA) to create a highly efficient tissue-clearing hydrogel system named the passive hydrogel clearing system (PHCS). PHCS achieved efficient tissue clearing through a single-step tissue gelation process. The resulting hydrogel-tissue complex exhibited thermoreversible properties, transitioning into a sol state upon heating and vice versa upon cooling. Notably, PHCS enabled media embedding, facilitating immunofluorescence histopathology. Additionally, the system demonstrated compatibility with various fluorescent probes, particularly lipophilic dyes. Our study successfully employed PHCS for the reconstruction of vascular structures within the intestine, enabling the generation of a 3D pathology model. These findings suggest that PHCS is a promising novel method for fabricating hydrogels for tissue clearing and holds great potential for application as a mounting medium for morphological imaging.

The Cervical Intervertebral Foramen: Microanatomy, Pathology, and Clinical Implications.

This is an evidence-based narrative review article. We hope to provide a primer on cervical intervertebral foramen (cIVF) anatomy for spine surgeons, interventionalists, and physiatrists who regularly treat cervical spine pathology, and encourage further exploration of this topic. This corridor for exiting cervical nerve roots is characterized by its intricate microanatomy involving ligamentous, nervous, and vascular structures. Degenerative changes such as facet hypertrophy and disc herniations alter these relationships, potentially leading to nerve root compression and cervical radiculopathy. This review synthesizes existing knowledge on the cIVF. Key imaging, cadaveric, and clinical studies serve as a foundation for this anatomic review. We explore topics such as dynamic changes that affect foraminal size and their implications for nerve root compression, the relationship of the dorsal root ganglion to the cervical foramen, and the function and clinical significance of foraminal ligaments, arteries, and veins. Changes in the cIVF are frequently the basis of cervical degenerative pathologies. A comprehensive understanding of its microanatomical structure will allow the practitioner to better treat the underlying disease process causing their symptoms and signs.

Polysaccharides from Ostrea rivularis alleviate type II diabetes induced-retinopathy and VGEF165-induced angiogenesis via PI3K/AKT signaling pathway

The purpose of this study was to investigate the role of polysaccharides from Ostrea rivularis Gloud (ORPs) in the progression of diabetic retinopathy (DR) and its anti-angiogenic effect on endothelial cell. Transgenic db/db mice with DR model were used to evaluate the protective effect of ORPs on retinal damage. It was found that ORPs could down-regulated levels of random blood glucose and fasting insulin, and further ameliorate retinal structure abnormalities as well as vascular network structure. Moreover, ORPs could reduce the expression of VEGF in retinal tissue and lessen pathological angiogenesis, thus slowing the progression of DR. In vitro, the proliferation, migration and tube formation of VGEF165-induced EA.hy926 cells were inhibited with ORPs administration. Furthermore, the expression of related proteins in the PI3K/AKT pathway and angiogenesis related factors were improved after ORPs intervention. Overall, these findings suggested that ORPs could effectively control the development of DR, and inhibit VGEF165-induced EA.hy926 cells proliferation, migration and tube formation, which effects might work through blocking the activation of PI3K/AKT signaling pathway.

Microvascular flow imaging of fibroids: A prospective pilot study.

Imaging fibroid vascularity may predict fibroid growth and aid to determine most appropriate therapy. Microvascular (MV) flow imaging is relatively new and is able to detect slow flow in small vessels. Data on feasibility, reproducibility, and reliability of MV-flow imaging in fibroids is lacking. The purpose of our study was to determine the reproducibility of MV-flow imaging and to explore this technique for clinical practice for assessing blood flow in fibroids. Thirty patients with one or multiple fibroids (diameter 1.5-12.0 cm) were prospectively included. Transvaginal ultrasound scanning was performed in B-mode, 2D MV-Flow™, 2D and 3D power Doppler mode (HERA W10, Samsung) by two experienced gynecologists at a tertiary care clinic from February to December 2021. The primary outcome was intra- and interobserver agreement of the vascular index (VI) and color score (CS). The following parameters: '2D MV-flow VI', '3DPD VI', '2D MV-flow CS' and '2DPD CS' were measured offline in the center, pseudocapsule, and entire fibroid. Secondary offline outcomes for exploring 2D MV-flow for clinical practice, included (1) ability to discern vascular structures, (2) assessing the degree of vascularity via CS and calculating a VI, and (3) determining penetration depth of the ultrasound signal in both power Doppler and MV-flow imaging. All scans of the 30 included patients were of sufficient quality to analyze. Inter- and intra-observer correlations of all studied parameters were good to excellent, both for 2D MV-flow and 2D power Doppler (intercorrelation coefficient 0.992-0.996). Using 2D MV-flow different vascular structures were visible in detail, in contrary to using 2D and 3D power Doppler. In significantly more fibroids central flow could be visualized using 2D MV-flow (63%) than with 2D power Doppler (13%,p = 0.001). Finally, penetration of the ultrasound signal was deeper using 2D MV-flow (3.92 cm) than with 2D power Doppler (2.95 cm, p = 0.001). Using 2D MV-flow imaging for determining vascularity is highly reproducible. It has potential added value for clinical practice as it depicts detailed vascular structures and the degree of vascularity, especially in the center of the fibroid.

Exploring arterial anatomy of the internal capsule: an analysis of the deep vascular structures and related white matter pathways.

The internal capsule is supplied by perforators originating from the internal carotid artery, middle cerebral artery, anterior choroidal artery and anterior cerebral artery. The aim of this study is to examine the vascular anatomy of the internal capsule, along with its related white matter anatomy, in order to prevent potential risks and complications during surgical interventions. Twenty injected hemispheres prepared according to the Klingler method were dissected. Dissections were photographed at each stage. The findings obtained from the dissections were illustrated to make them more understandable. Additionally, the origins of the arteries involved in the vascularization of the internal capsule, their distances to bifurcations, and variations in supplying territories have been thoroughly examined. The insular cortex and the branches of the middle cerebral artery on the insula and operculum were observed. Following decortication of the insular cortex, the extreme capsule, claustrum, external capsule, putamen and globus pallidus structures were exposed. The internal capsule is shown together with the lenticulostriate arteries running on the anterior, genu and posterior limbs. Perforators supplying the internal capsule originated from the middle cerebral artery, anterior cerebral artery, internal carotid artery and anterior choroidal artery. The internal capsule's vascular supply varied, with the medial lenticulostriate arteries (MLA) and lateral lenticulostriate arteries (LLA) being the primary arteries. The anterior limb was most often supplied by the MLA, while the LLA and anterior choroidal artery dominated the genu and posterior limb. The recurrent artery of Heubner originated mostly from the A2 segment. The distance from the ICA bifurcation to the origin of the first LLA on M1 is 9.55 ± 2.32mm, and to the first MLA on A1 is 5.35 ± 1.84mm. MLA branching from A1 and proximal A2 ranged from 5 to 9, while LLA originating from the MCA ranged from 7 to 12. This study provides comprehensive understanding of the arterial supply to the internal capsule by combining white matter dissection. The insights gained from this study can help surgeons plan and execute procedures including oncological, psychosurgical, and vascular more accurately and safely. The illustrations derived from the dissections serve as valuable educational material for young neurosurgeons and other medical professionals.

VesselBoost: A Python Toolbox for Small Blood Vessel Segmentation in Human Magnetic Resonance Angiography Data

Magnetic resonance angiography (MRA) performed at ultra-high magnetic field provides a unique opportunity to study the arteries of the living human brain at the mesoscopic level. From this, we can gain new insights into the brain’s blood supply and vascular disease affecting small vessels. However, for quantitative characterization and precise representation of human angioarchitecture to, for example, inform blood-flow simulations, detailed segmentations of the smallest vessels are required. Given the success of deep learning-based methods in many segmentation tasks, we explore their application to high-resolution MRA data and address the difficulty of obtaining large data sets of correctly and comprehensively labelled data. We introduce VesselBoost, a vessel segmentation toolbox, which utilizes deep learning and imperfect training labels for accurate vasculature segmentation. To enhance the segmentation models’ robustness and accuracy, VesselBoost employs an innovative data augmentation technique, which captures the resemblance of vascular structures across scales by zooming in or out on input image patches—virtually creating diverse scale vascular data. This approach enables detailed vascular segmentation and ensures the model’s ability to generalize across various scales of vascular structures.

When Undergoing Thoracic CT (Computerized Tomography) Angiographies for Congenital Heart Diseases, Is It Possible to Identify Coronary Artery Anomalies?

The aim of this study was to evaluate the coronary arteries in patients undergoing thoracic CT angiography for congenital heart disease, to determine the frequency of detection of coronary artery anomalies in congenital heart diseases, and to determine which type of anomaly is more common in which disease. In our investigation, a 128-detector multidetector computed tomography machine was used to perform thorax CT angiography. The acquisition parameters were set to 80-100 kVp based on the patient's age and mAs that the device automatically determined based on the patient's weight. During the examination, an intravenous (IV) nonionic contrast material dose of 1-1.5 mL/kg was employed. An automated injector was used to inject contrast material at a rate of 1.5-2 mL/s. In the axial plane, 2.5 mm sections were extracted, and they were rebuilt with 0.625 mm section thickness. Between October 2022 and May 2024, 132 patients who were diagnosed with congenital heart disease by echocardiography and underwent Thorax CT angiography in our department were retrospectively evaluated. Of the evaluated patients, 32 were excluded with exclusion criteria such as patients being younger than 3 months, older than 18 years, insufficient contrast enhancement in imaging and contrast-enhanced imaging, thin vascular structure, and motion and contrast artifacts; the remaining 100 patients were included in this study. The age range of these patients was 3 months to 18 years (mean age 4.4 years). In congenital heart diseases, attention to the coronary arteries on thoracic CT angiography examination in the presence of possible coronary anomalies may provide useful information.

MPCCN: A Symmetry-Based Multi-Scale Position-Aware Cyclic Convolutional Network for Retinal Vessel Segmentation

In medical image analysis, precise retinal vessel segmentation is crucial for diagnosing and managing ocular diseases as the retinal vascular network reflects numerous health indicators. Despite decades of development, challenges such as intricate textures, vascular ruptures, and undetected areas persist, particularly in accurately segmenting small vessels and addressing low contrast in imaging. This study introduces a novel segmentation approach called MPCCN that combines position-aware cyclic convolution (PCC) with multi-scale resolution input to tackle these challenges. By integrating standard convolution with PCC, MPCCN effectively captures both global and local features. A multi-scale input module enhances feature extraction, while a weighted-shared residual and guided attention module minimizes background noise and emphasizes vascular structures. Our approach achieves sensitivity values of 98.87%, 99.17%, and 98.88%; specificity values of 98.93%, 97.25%, and 99.20%; accuracy scores of 97.38%, 97.85%, and 97.75%; and AUC values of 98.90%, 99.15%, and 99.05% on the DRIVE, STARE, and CHASE_DB1 datasets, respectively. In addition, it records F1 scores of 90.93%, 91.00%, and 90.55%. Experimental results demonstrate that our method outperforms existing techniques, especially in detecting small vessels.

A rare combined variation of left renal vasculature in a human cadaver: embryological basis and clinical significance.

Classically, a single renal artery supplies, and a single renal vein drains each kidney. The morphology and variations in the renal vascular structures are of great importance when performing any type of renal surgery. The present case describes a rare combination of renal vasculature variation in a formalin-fixed, Chinese male cadaver. In this case, the left kidney is drained by a main renal vein (MRV) and an inferior renal vein (IRV), the latter might be the remnant of the left dorsal renal vein during the embryonic period. Two sets of renal arteries are present in this case, possibly due to persistent mesonephric arteries during embryonic development. Describing such anatomical variations is not only of academic interest but also important to help radiologists with the correct interpretation of image examinations and for surgeons to be prepared in advance.

Perspective or Spectacle? Teaching thoracic aortic anatomy in a mixed reality assisted educational approach– a two-armed randomized pilot study

PurposeAnatomical understanding is an important basis for medical teaching, especially in a surgical context. The interpretation of complex vascular structures via two-dimensional visualization can yet be difficult, particularly for students. The objective of this study was to investigate the feasibility of an MxR-assisted educational approach in vascular surgery undergraduate education, comparing an MxR-based teaching-intervention with CT-based material for learning and understanding the vascular morphology of the thoracic aorta.MethodsIn a prospective randomized controlled trial learning success and diagnostic skills following an MxR- vs. a CT-based intervention was investigated in 120 thoracic aortic visualizations. Secondary outcomes were motivation, system-usability as well as workload/satisfaction. Motivational factors and training-experience were also assessed. Twelve students (7 females; mean age: 23 years) were randomized into two groups undergoing educational intervention with MxR or CT.ResultsEvaluation of learning success showed a mean improvement of 1.17 points (max.score: 10; 95%CI: 0.36–1.97). The MxR-group has improved by a mean of 1.33 [95% CI: 0.16–2.51], against 1.0 points [95% CI: -0.71- 2.71] in the CT-group. Regarding diagnostic skills, both groups performed equally (CT-group: 58.25 ± 7.86 vs. MxR-group:58.5 ± 6.60; max. score 92.0). 11/12 participants were convinced that MxR facilitated learning of vascular morphologies. The usability of the MxR-system was rated positively, and the perceived workload was low.ConclusionMxR-systems can be a valuable addition to vascular surgery education. Further evaluation of the technology in larger teaching situations are required. Especially regarding the acquisition of practical skills, the use of MxR-systems offers interesting application possibilities in surgical education.

Case Report: Unveiling an anomalous diaphragmatic paraganglioma mimicking a hepatic tumor

Abstract Paragangliomas are rare neuroendocrine tumors, often associated with catecholamine secretion. These tumors can arise in various locations, with the majority found in the abdomen and pelvis, while a smaller percentage occurs in the thorax and head and neck regions. Diaphragmatic paragangliomas are exceedingly rare, with only two documented cases in the literature. This report details a case of a primary diaphragmatic paraganglioma in a 59-year-old patient presenting with unexplained weight loss, tremors, and diaphoresis. Imaging studies revealed a mass in the right lobe of the liver, later identified as a diaphragmatic paraganglioma during surgery. The case underscores the importance of preoperative catecholamine assessment and careful surgical planning due to the risks associated with tumor manipulation. Complete surgical resection, although challenging, remains the definitive treatment, especially in hypervascular tumors located near major vascular structures.

Traumatic lateral spondyloptosis and lateraloptosis with partial improvement through posterior surgical approach: a review based on a case report

Introduction. Spondyloptosis or grade V of spondylolisthesis, spinal injury that involve 100 % mobilization of the vertebral body, is rare to find. Lateraloptosis, displacement of vertebral bodies, is even more rare a catastrophic.The aim of this study to introduce readers to this rare form of traumatic lumbar spine injury as well as to review current available therapeutic approaches.Case report. A 22-year-old male was admitted to the emergency room due to a fall from a moving truck. Physical examination revealed neurological deficit in the lower extremities, with muscle strength 0/5, and an ASIA B classification. Computed tomography study showed a complete lateroloptosis at the L3 –L4 level. The patient is admitted to the operating room for surgical treatment through a posterior approach. Successful arthrodesis and spinal alignment are achieved. Immediate postoperative period, showed no complications and the patient’s neurological function in the lower extremities was classified as ASIA C. In the posterior follow-up, the patient maintains the motor neurological function and recover the autonomic control of bladder function. With mild disability according to the Barthel Index of 90 points.Discussion. of the traumatic spinal injuries, spondyloptosis is the most infrequent and occurs secondary to high-energy mechanisms. It presents an incidence of complete neurological deficit in 80 % of patients. The objectives in surgical treatment are decompression of neurovascular structures, reduction of fracture dislocation to improve alignment in the sagittal and coronal plane, and instrumentation that allows stability. The posterior surgical approach offers advantages over the anterior approach. In the posterior approach, the facet joints can be manipulated more safely, decompress the nerve roots and the dural sac more easily, as well as less operating time and greater care of vascular structures such as the iliac vessels.Conclusion. Complex traumatic spinal injuries are associated with irreversible neurological damage. Achieving spinal stability and alignment allows optimizing physical therapy and rehabilitation for greater recovery. Severe spinal injuries, especially lateroptosis, are difficult to treat by surgical approach, however, the main objective is vertebral stabilization to allow physical therapy and early rehabilitation.

Nephronsparing surgery for retroperitoneal sarcomas

Objective: to clarify the indications for the use of nephron-sparing technologies in surgical treatment of patients with retroperitoneal sarcomas. Material and Methods. The study included 64 patients with primary retroperitoneal sarcomas with kidney and renal pedicle invasion, who underwent surgical treatment in the Thoracic-abdominal Department of the P.A. Herzen Moscow Oncology Research Institute from 2010 to 2021. Twenty-one patients underwent nephrectomies, and 43 patients underwent nephron-sparing surgery. The morphological profile of sarcomas, age and gender of the patients, feasibility of using nephron-sparing technologies, postoperative complications, and long-term outcomes in patients of both groups were analyzed. Results. Forty-three patients with primary retroperitoneal sarcomas with invasion of the renal parenchyma, ureter, and renal pedicle underwent nephron-sparing surgery (precision mobilization of the kidney, ureter and vascular structures of the kidney from tumor tissue, kidney resection, ureteral stenting, resection of the renal vein orifices, resection of the ureters, and kidney autotransplantation). Postoperative complications were observed in 19.0 % of nephrectomy group patients (4 pts: II, IIIB, IV and V types according to Clavien–Dindo) and in 30.2 % of nephron-sparing group patients (15 pts: types II – 8, IIIA – 1, IIIB – 3, IV – 1). No statistical differences in the relapse-free period and survival time between two groups were observed. The 1-, 3- and 5-year survival rates were 84.1 %, 65.9 %, and 51.4 %, respectively. Multifactorial analysis showed that mortality increased significantly in patients over 64 years of age and was associated with both disease recurrence and concomitant pathology (p=0.009). There was also a trend toward decreased survival in patients with leiomyosarcoma (p=0.066). Conclusion. In retroperitoneal sarcomas, tumor resection with preservation of organs and structures not directly invaded by the tumor is the optimal surgical strategy. Nephron-sparing technologies do not worsen both immediate and long-term treatment outcomes. For leiomyosarcoma, tumor resection with nephrectomy is the most suitable approach.

Mechanisms underlying age-associated exacerbation of pulmonary veno-occlusive disease.

Pulmonary veno-occlusive disease (PVOD) is a rare but severe form of pulmonary hypertension characterized by the obstruction of pulmonary arteries and veins, causing increased pulmonary artery pressure and leading to right ventricular (RV) heart failure. PVOD is often resistant to conventional pulmonary arterial hypertension (PAH) treatments and has a poor prognosis, with a median survival time of 2-3 years after diagnosis. We previously showed that the administration of a chemotherapy agent mitomycin C (MMC) in rats mediates PVOD through the activation of the eukaryotic initiation factor 2 (eIF2) kinase protein kinase R (PKR) and the integrated stress response (ISR), resulting in the impairment of vascular endothelial junctional structure and barrier function. Here, we demonstrate that aged rats over 1 year exhibit more severe vascular remodeling and RV hypertrophy than young adult rats following MMC treatment. This is attributed to an age-associated elevation of basal ISR activity and depletion of protein phosphatase 1, leading to prolonged eIF2 phosphorylation and sustained ISR activation. Pharmacological blockade of PKR or ISR mitigates PVOD phenotypes in both age groups, suggesting that targeting the PKR/ISR axis could be a potential therapeutic strategy for PVOD.

Accelerating healing at high altitudes: Oxygen and bFGF delivery through nanoparticle-loaded gel dressings

High altitude environment is mainly characterized by low oxygen. Due to persistent hypoxia, nonhealing wounds are common in high-altitude areas. Moreover, Basic fibroblast growth factor (bFGF) is a versatile biologically active substance that has crucial impact on wound healing. Given the limited availability of atmospheric oxygen and reduced blood oxygen saturation in high-altitude area, and the challenge that arises from direct oxygen and bFGF delivery to wounds through the traumatized vascular structure, it necessitates an innovative solution for local and permeable delivery of oxygen and bFGF. In this study, we present a strategy that involves revamping traditional gel-based wound dressings through the incorporation of nanoparticles encapsulating oxygen and bFGF, engineered to facilitate the localized delivery of dissolved oxygen and bFGF to wound surfaces. The prospective evaluation of this delivery technique's therapeutic impacts on epithelial, endothelial and fibroblasts cells can be materialized. Further experiment corroborated these effects on a high-altitude wounds' murine model. Given its biocompatibility, efficacy, and utility, we posit that NOB-Gel exhibits remarkable translational potential for managing and hastening the healing process of an array of clinical wounds, more so for wounds inflicted at high altitudes.

Serjania piscatoria (Paullinieae, Sapindaceae) as a symbol of vascular variants polymorphism

Abstract Serjania is the only genus of the Paullinieae tribe that exhibits all patterns of vascular variants and includes S. piscatoria which shows a complex vascular structure that has intrigued botanists for centuries. Here, we analysed the stem development of S. piscatoria in an evolutionary context. We studied four individuals using standardized anatomical techniques and employed DNA sequencing to determine the species’ phylogenetic position. Additionally, we explored the evolution of stem developmental diversity using stochastic character mapping of the categories and patterns of vascular variants. We find that disparate ontogenetic processes determine the stem development in S. piscatoria, which results in vascular variants derived from procambial variants, cambial variants, and ectopic cambia. This diversity underscores the developmental lability of vascular meristems, making the species' vascular system structurally diverse and polymorphic. The complex vascular system observed in S. piscatoria evolved within a lineage composed of species with compound stems. These findings provide evidence for the intricate and labile evolutionary history of stem vasculature in Serjania, and the value of studying vascular variants to unravel the patterns and processes shaping plant diversity.

Proximal Fibulectomy for Giant Cell Tumours: What Works!

Giant cell tumor of bone (GCTB) is the most common primary tumor of proximal fibula. Because of its close proximity to vascular structures, common peroneal nerve (CPN) and attachment of lateral collateral ligament (LCL), proximal fibulectomy poses unique challenges. We analyzed oncological and functional outcome of patients who underwent proximal fibulectomy for GCTB of proximal fibula. Between January 2006 and December 2020, 23 patients underwent proximal fibulectomy for GCTB of proximal fibula, four were recurrent tumors. Mean resection length was 9cm (5 to 15cm). The LCL and biceps tendon were not reconstructed in 22 cases. The common peroneal nerve was sacrificed in seven patients including three recurrent cases. Functional status was assessed using the Musculoskeletal Tumour Society (MSTS) scoring system. There were two vascular complications and one infection. With 4 patients lost to follow up, mean follow up was 90months (12 to 197). No patient had local or distant recurrence. Mean MSTS score was 26 (21 to 30). Eleven of 23 patients (48%) had loss of common peroneal nerve function with poorer functional outcome. No patient had symptoms suggestive of knee instability. Proximal fibulectomy is oncologically safe. Reconstruction of the LCL attachment is not mandatory and patients do not have symptomatic knee instability. Functional outcomes are compromised after sacrifice of common peroneal nerve and may be potentially improved with tendon transfers at index surgery.

3D Vessel Segmentation With Limited Guidance of 2D Structure-Agnostic Vessel Annotations.

Delineating 3D blood vessels of various anatomical structures is essential for clinical diagnosis and treatment, however, is challenging due to complex structure variations and varied imaging conditions. Although recent supervised deep learning models have demonstrated their superior capacity in automatic 3D vessel segmentation, the reliance on expensive 3D manual annotations and limited capacity for annotation reuse among different vascular structures hinder their clinical applications. To avoid the repetitive and costly annotating process for each vascular structure and make full use of existing annotations, this paper proposes a novel 3D shape-guided local discrimination (3D-SLD) model for 3D vascular segmentation under limited guidance from public 2D vessel annotations. The primary hypothesis is that 3D vessels are composed of semantically similar voxels and often exhibit tree-shaped morphology. Accordingly, the 3D region discrimination loss is firstly proposed to learn the discriminative representation measuring voxel-wise similarities and cluster semantically consistent voxels to form the candidate 3D vascular segmentation in unlabeled images. Secondly, the shape distribution from existing 2D structure-agnostic vessel annotations is introduced to guide the 3D vessels with the tree-shaped morphology by the adversarial shape constraint loss. Thirdly, to enhance training stability and prediction credibility, the highlighting-reviewing-summarizing (HRS) mechanism is proposed. This mechanism involves summarizing historical models to maintain temporal consistency and identifying credible pseudo labels as reliable supervision signals. Only guided by public 2D coronary artery annotations, our method achieves results comparable to SOTA barely-supervised methods in 3D cerebrovascular segmentation, and the best DSC in 3D hepatic vessel segmentation, demonstrating the effectiveness of our method.

Vascular responsiveness to low-dose dexamethasone in extremely premature infants: negative influence of fetal growth restriction.

Dexamethasone is frequently prescribed for preterm infants to wean from respiratory support and/or to facilitate extubation. This pre-/postintervention prospective study ascertained the impact on clinical (respiratory support) and echocardiographic parameters after dexamethasone therapy in preterm fetal growth restriction (FGR) infants compared with appropriate for gestational age (AGA) infants. Echocardiography was performed within 24 h before the start and after completion of 10-day therapy. Parameters assessed included those reflecting pulmonary vascular resistance and right ventricular output. Seventeen FGR infants (birth gestation and birth weight, 25.2 ± 1.1 wk and 497 ± 92 g, respectively) were compared with 22 AGA infants (gestation and birth weight, 24.5 ± 0.8 and 663 ± 100 g, respectively). Baseline respiratory severity score (mean airway pressure × fractional inspired oxygen) was comparable between the groups, (median [interquartile range] FGR, 10 [6, 13] vs. AGA, 8 ± 2.8, P = 0.08). Pre-dexamethasone parameters of pulmonary vascular resistance (FGR, 0.19 ± 0.03 vs. AGA, 0.2 ± 0.03, P = 0.16) and right ventricular output (FGR, 171 ± 20 vs. 174 ± 17 mL/kg/min, P = 0.6) were statistically comparable. At post-dexamethasone assessments, the decrease in the respiratory severity score was significantly greater in AGA infants (median [interquartile range] FGR, 10 [6, 13] to 9 [2.6, 13.5], P = 0.009 vs. AGA, 8 ± 2.8 to 3 ± 1, P < 0.0001). Improvement in measures of pulmonary vascular resistance (ratio of time to peak velocity to right ventricular ejection time) was greater in AGA infants (FGR, 0.19 ± 0.03 to 0.2 ± 0.03, P = 0.13 vs. AGA 0.2 ± 0.03 to 0.25 ± 0.03, P < 0.0001). The improvement in right ventricular output was significantly greater in AGA infants (171 ± 20 to 190 ± 21, P = 0.014 vs. 174 ± 17 to 203 ± 22, P < 0.0001). This highlights differential cardiorespiratory responsiveness to dexamethasone in extremely preterm FGR infants, which may reflect the in utero maladaptive state.NEW & NOTEWORTHY Dexamethasone (DEX) is frequently used in preterm infants dependent on ventilator support. Differences in vascular structure and function that may have developed prenatally arising from the chronic intrauterine hypoxemia in FGR infants may adversely affect responsiveness. The clinical efficacy of DEX was significantly less in FGR (birth weight < 10th centile) infants, compared with appropriate for gestational age (AGA) infants. Echocardiography showed significantly less improvement in pulmonary vascular resistance in FGR, compared with AGA infants.