Surgical Management of Vascular Malformations of the Upper Extremity: A 12-Year Retrospective Cohort Study.

INTRODUCTION: Vascular malformations (VMs) typically appear at birth and grow commensurately with patients. They can vary broadly in vessel type and tissue involvement, and upper extremity (UE) VMs can pose unique functional and aesthetic challenges in children. Given the advent of operative and nonoperative technologies like sclerotherapy and medications, a contemporary review of the surgical management of UE VMs is warranted. METHODS: We performed a retrospective review of all patients who had surgical management of VMs from 2010 to 2021 at The Children's Hospital of Philadelphia. Demographics, lesion characteristics, treatment (including preceding nonsurgical therapies), complications, and final outcomes were recorded. Operative notes were reviewed for date of operation, depth of excision, type of closure, and current procedural terminology code. RESULTS: Sixty-seven patients with 88 procedures were studied. Average patient age was 5.8 years, with 64% White and 67% male. Venous (34%) and lymphatic (19%) malformations were most common, and anatomic locations were most frequently on the hand (33%) and forearm (25%). The average lesion diameter was 4.2 cm, although this varied by location (eg, 2.9 cm, hand; 11.1 cm, chest wall). Fifty-eight patients (87%) underwent surgical excision as their index procedure, and 9 had sclerotherapy before surgery. Thirty-nine patients (60%) had subcutaneous excisions, and the remainder required subfascial or intramuscular excisions. Nearly all excisions were closed primarily (97%). Of the 53 patients with documented follow-up, 32 patients (60%) had complete resolution of their lesion as of their final visit. Thirty of these 32 patients with no clinical evidence of residual VM had only 1 surgery for excision. CONCLUSION: Upper extremity VMs were composed of diverse conditions with varying vessel types, size, depth, and anatomic sites. Surgical excision of VMs of the UE was safe and effective. A majority of VMs were fully excised after 1 procedure and frequently closed primarily with relatively low complication rates. Future work should investigate decision-making and outcomes of all treatment options of VMs of the UE for optimal functionality and aesthetics.

Is Venous Thromboembolism Prophylaxis Needed in Patients Undergoing Knee Arthroscopy? A Prospective Observational Study.

BACKGROUND: Although rare, deep vein thrombosis is a potentially life-threatening complication of knee arthroscopy. There are scanty literature analysing deep vein thrombosis after arthroscopy in Nepal. This study aimed to identify the prevalence of deep vein thrombosis in patients undergoing knee arthroscopy without chemoprophylaxis postoperatively at 2 weeks and 6 weeks, respectively. The study also aimed to estimate the risk of deep vein thrombosis in these patients by using Caprini Risk Assessment Model. METHODS: This prospective observational study was conducted at AKB center, B and B Hospital, Gwarko, Lalitpur, over a period of 16 months. All patients who underwent arthroscopy knee surgeries fulfilling the inclusion criteria were included in the study. The primary outcome measure was the prevalence of deep vein thrombosis as diagnosed by compression color-coded ultrasonography of the popliteal vein and calf vein at 2 weeks and 6 weeks postoperatively. The secondary outcome measure was the prevalence of deep vein thrombosis in the risk groups according to Caprini Risk Assessment Model. RESULTS: Out of 612 patients who underwent arthroscopic knee surgeries during the study period, 2 patients (0.33%) developed deep vein thrombosis at 6 weeks follow-up as diagnosed with ultrasonography of the popliteal and calf veins. The prevalence rate in high-risk group was 0.33% (1 in 307) and in very high-risk group was 5.88% (1 in 17). CONCLUSIONS: There was a low prevalence of deep vein thrombosis without chemoprophylaxis following knee arthroscopy in our study. There was higher prevalence of deep vein thrombosis in very high-risk group patients, so close monitoring of such patients during follow-up is recommended.

Resection of a retroperitoneal lumbar vein aneurysm: A case report.

We present a rare case involving a 54-year-old man with a history of pancreatitis who developed a retroperitoneal lumbar vein aneurysm that was initially misidentified as a pancreatic pseudocyst. Subsequent imaging revealed an enlarged mass and retroperitoneal perforation. Despite initial hesitation, the patient eventually underwent radical surgery that enabled the successful removal of the mass, which was near the inferior vena cava. Pathological examination confirmed varicose veins, and the final diagnosis was lumbar vein aneurysm in the retroperitoneum. The patient's postoperative recovery was uneventful, with no symptoms or recurrence observed on 6-month follow-up imaging. We investigated a potential link between pancreatitis and recurrent bleeding due to weakened venous walls. The findings from this case underscore the rarity of venous aneurysms and the diagnostic and treatment challenges due to the limited number of cases; furthermore, they emphasize that surgery should be carefully considered based on the lesion location and associated risks.

Circuit analogy unveiled the haemodynamic effects of the posterior cross vein in the wing vein networks.

We investigated the wing vein network topology in fruit flies and observed that the posterior cross vein (PCV) disrupts the symmetry of the entire network. The fluidic engineering function of this vein's disposition remains unexplored although the wing vein network is known to transport blood. We examined the fluid mechanical effects of the PCV's disposition on this blood-transporting network through numerical simulations involving the removal and rearrangement of the vein, avoiding impractical physical manipulation. We characterised the geometry of each wing membrane cell, a portion of the wing membrane surrounded by a group of veins, by determining the ratio of its surface area to the contact area with the veins. We considered this ratio in association with the flow velocities of seeping water from the blood within the veins to the membrane and evaporating water from the membrane, based on the mass conservation law. We observed that the division of a membrane cell by the PCV maximises the ratio of the areas in the divided cell on the wing-tip side by virtually shifting this vein's connections in our geometric membrane model. We derived blood flow rate and pressure loss within the venous network from their geometry, using an analogy of the venous network with a circuit consisting of hydraulic resistors based on Kirchhoff and Ohm's laws. The overall pressure loss in the network decreased by 20% with the presence of the PCV functioning as a paralleled hydraulic resistor. By contrast, any other cross-vein computationally arranged on another membrane cell as the PCV's substitution did not exhibit a larger reduction in the pressure loss. Overall, our numerical analyses, leveraging geometry and a circuit analogy, highlighted the effects of the PCV's presence and position on the blood-transporting vein network.

Parenchymal cues define Vegfa-driven venous angiogenesis by activating a sprouting competent venous endothelial subtype.

Formation of organo-typical vascular networks requires cross-talk between differentiating parenchymal cells and developing blood vessels. Here we identify a Vegfa driven venous sprouting process involving parenchymal to vein cross-talk regulating venous endothelial Vegfa signaling strength and subsequent formation of a specialized angiogenic cell, prefabricated with an intact lumen and pericyte coverage, termed L-Tip cell. L-Tip cell selection in the venous domain requires genetic interaction between vascular Aplnra and Kdrl in a subset of venous endothelial cells and exposure to parenchymal derived Vegfa and Apelin. Parenchymal Esm1 controls the spatial positioning of venous sprouting by fine-tuning local Vegfa availability. These findings may provide a conceptual framework for understanding how Vegfa generates organo-typical vascular networks based on the selection of competent endothelial cells, induced via spatio-temporal control of endothelial Kdrl signaling strength involving multiple parenchymal derived cues generated in a tissue dependent metabolic context.

The impact of vascular margin invasion on local recurrence after pancreatoduodenectomy in pancreatic adenocarcinoma.

PURPOSE: Pancreatic ductal adenocarcinoma (PADC) still has nowadays a very impaired long-term survival. Most studies are focused on overall survival; however, local recurrence occurs about up to 50% of cases and seems to be highly related with margin resection status. We aim to analyze the impact of vascular resection margins on local recurrence (LR) and to assess its impact on overall and disease-free survival. METHODS: Eighty out of 191 patients who underwent pancreatoduodenectomy in a university hospital between 2006 and 2021 with PDAC diagnosis were analyzed and vascular margin status specifically addressed. Univariate and multivariate were performed. Time to LR was compared by using the Kaplan-Meier method and prognostic factors assessed using Cox regression hazards model. RESULTS: LR appeared in 10 (50%) of the overall R1 resections in the venous margin and 9 (60%) in the arterial one. Time to LR was significantly shorter when any margin was overall affected (23.2 vs 44.7 months, p = 0.01) and specifically in the arterial margin involvement (13.7 vs 32.1 months, p = 0.009). Overall R1 resections (HR 2.61, p = 0.013) and a positive arterial margin (HR 2.84, p = 0.012) were associated with local recurrence on univariate analysis, whereas arterial positive margin remained significant on multivariate analysis (HR 2.70, p = 0.031). CONCLUSIONS: Arterial margin invasion is correlated in our cohort with local recurrence. Given the limited ability to modify this margin intraoperatively, preoperative therapies should be considered to improve local margin clearance.

Cerebral Venous Sinus Thrombosis as an Initial Presentation of Nephrotic Syndrome: A Case Report.

Cerebral sinovenous thrombosis (CSVT) encompasses a spectrum of disorders involving thrombosis of the cerebral venous system. As shown by previous epidemiological studies, the prevalence of cerebral sinovenous thrombosis is 4-7 cases per million people. Nephrotic syndrome was very rarely associated with thrombosis cerebral veins or sinuses. Hypercoagulability and thrombotic complications in nephrotic syndrome are most commonly seen in deep veins of the lower extremities and renal veins. Our case highlights a unique scenario in which cerebral sinovenous thrombosis was the initial presentation of nephrotic syndrome in a patient that was not an important past medical or surgical problem. The patient was brought to the emergency department with severe headache, vomiting, altered mental status, and generalized body swelling. Laboratory results showed proteinuria, hypoalbuminemia and hyperlipidemia. Non-contrast brain CT demonstrated hemorrhagic venous infarct associated with vasogenic edema. A subsequent brain MR venogram demonstrated occlusion of superior sagittal and right transverse sinuses. She was managed with low molecular weight heparin and intervenous corticosteroids then shifted to rivaroxaban and oral steroids, respectively, which resulted in massive clinical improvement and resolution of thrombus.

A Vascular Feature Detection and Matching Method Based on Dual-Branch Fusion and Structure Enhancement.

How to obtain internal cavity features and perform image matching is a great challenge for laparoscopic 3D reconstruction. This paper proposes a method for detecting and associating vascular features based on dual-branch weighted fusion vascular structure enhancement. Our proposed method is divided into three stages, including analyzing various types of minimally invasive surgery (MIS) images and designing a universal preprocessing framework to make our method generalized. We propose a Gaussian weighted fusion vascular structure enhancement algorithm using the dual-branch Frangi measure and MFAT (multiscale fractional anisotropic tensor) to address the structural measurement differences and uneven responses between venous vessels and microvessels, providing effective structural information for vascular feature extraction. We extract vascular features through dual-circle detection based on branch point characteristics, and introduce NMS (non-maximum suppression) to reduce feature point redundancy. We also calculate the ZSSD (zero sum of squared differences) and perform feature matching on the neighboring blocks of feature points extracted from the front and back frames. The experimental results show that the proposed method has an average accuracy and repeatability score of 0.7149 and 0.5612 in the Vivo data set, respectively. By evaluating the quantity, repeatability, and accuracy of feature detection, our method has more advantages and robustness than the existing methods.

Inferior vena cava reconstruction with non-fascial autologous peritoneum: Retrospective study and literature review.

BACKGROUND: Inferior vena cava (IVC) resection is essential for complete (R0) excision of some malignancies. However, the optimal material for IVC reconstruction remains unclear. Our objective is to demonstrate the efficacy, safety, and advantages of using Non-Fascial Autologous Peritoneum (NFAP) for IVC reconstruction. To conduct a literature review of surgical strategies for tumors involving the IVC. METHODS: We reviewed all IVC reconstructions performed at our institution between 2015 and 2023. Preoperative, operative, postoperative, and follow-up data were collected and analyzed. RESULTS: A total of 33 consecutive IVC reconstructions were identified: seven direct sutures, eight venous homografts (VH), and 18 NFAP. With regard to NFAP, eight tubular (mean length, 12.5 cm) and 10 patch (mean length, 7.9 cm) IVC reconstructions were performed. Resection was R0 in 89% of the cases. Two patients had Clavien-Dindo grade I complications, 2 grade II, 2 grade III and 2 grade V complications. The only graft-related complication was a case of early partial thrombosis, which was conservatively treated. At a mean follow-up of 25.9 months, graft patency was 100%. There were seven recurrences and six deaths. Mean overall survival (OS) was 23.4 months and mean disease-free survival (DFS) was 14.4 months. According to our results, no statistically significant differences were found between NFAP and VH. CONCLUSIONS: NFAP is a safe and effective alternative for partial or complete IVC reconstruction and has many advantages over other techniques, including its lack of cost, wide and ready availability, extreme handiness, and versatility. Further comparative studies are required to determine the optimal technique for IVC reconstruction.

Anatomy and anatomical variations of adrenal veins and its application to adrenal venous sampling.

PURPOSE: Our aim was to study the anatomy of the left and right main adrenal veins (LAV and RAV) and to identify their anatomical variations in order to see the practical application of these findings to adrenal venous sampling (AVS). METHODS: Our work is based on dissection of 80 adrenal glands from fresh corpses in the forensic medicine department. We studied the number, the drainage, the direction and the level of termination of the main adrenal veins. RESULTS: The average length of the LAV was 21 mm. It ended in 100% of cases at the upper edge of the left renal vein with a mean connection angle of 70° and after an anastomosis with the lower phrenic vein in 36 cases(90%). The average length of the RAV was 9 mm. It ended in 100% of cases at the level of the retro hepatic inferior vena cava (IVC) mainly on its posterior face in 21 cases (53%) and on its right lateral border in 18 cases (45%). The mean angle of the RAV in relation to the vertical axis of the IVC was 40°, with extremes ranging from 15° to 90°. CONCLUSIONS: AVS seems to be easier on the left than on the right side because of the greater length of the adrenal vein (21 mm vs. 9 mm) and a greater angle of connection (70° with the left renal vein vs. 40° with the IVC), which explains the lower success rate of cannulation and the more frequent occurrence of blood sample contamination on the right side.

Whole-lesion assessment of volume and signal changes after sclerotherapy of extremity venous malformations.

PURPOSE: To investigate quantitative changes in MRI signal intensity (SI) and lesion volume that indicate treatment response and correlate these changes with clinical outcomes after percutaneous sclerotherapy (PS) of extremity venous malformations (VMs). METHODS: VMs were segmented manually on pre- and post-treatment T2-weighted MRI using 3D Slicer to assess changes in lesion volume and SI. Clinical outcomes were scored on a 7-point Likert scale according to patient perception of symptom improvement; treatment response (success or failure) was determined accordingly. RESULTS: Eighty-one patients with VMs underwent 125 PS sessions. Treatment success occurred in 77 patients (95 %). Mean (±SD) changes were -7.9 ± 24 cm3 in lesion volume and -123 ± 162 in SI (both, P <.001). Mean reduction in lesion volume was greater in the success group (-9.4 ± 24 cm3) than in the failure group (21 ± 20 cm3) (P =.006). Overall, lesion volume correlated with treatment response (ρ = -0.3, P =.004). On subgroup analysis, volume change correlated with clinical outcomes in children (ρ = -0.3, P =.03), in sodium tetradecyl sulfate-treated lesions (ρ = -0.5, P =.02), and in foot lesions (ρ = -0.6, P =.04). SI change correlated with clinical outcomes in VMs treated in 1 PS session (ρ = -0.3, P =.01) and in bleomycin-treated lesions (ρ = -0.4, P =.04). CONCLUSIONS: Change in lesion volume is a reliable indicator of treatment response. Lesion volume and SI correlate with clinical outcomes in specific subgroups.

Venous-plexus-associated lymphoid hubs support meningeal humoral immunity.

There is increasing interest in how immune cells in the meninges-the membranes that surround the brain and spinal cord-contribute to homeostasis and disease in the central nervous system1,2. The outer layer of the meninges, the dura mater, has recently been described to contain both innate and adaptive immune cells, and functions as a site for B cell development3-6. Here we identify organized lymphoid structures that protect fenestrated vasculature in the dura mater. The most elaborate of these dural-associated lymphoid tissues (DALT) surrounded the rostral-rhinal confluence of the sinuses and included lymphatic vessels. We termed this structure, which interfaces with the skull bone marrow and a comparable venous plexus at the skull base, the rostral-rhinal venolymphatic hub. Immune aggregates were present in DALT during homeostasis and expanded with age or after challenge with systemic or nasal antigens. DALT contain germinal centre B cells and support the generation of somatically mutated, antibody-producing cells in response to a nasal pathogen challenge. Inhibition of lymphocyte entry into the rostral-rhinal hub at the time of nasal viral challenge abrogated the generation of germinal centre B cells and class-switched plasma cells, as did perturbation of B-T cell interactions. These data demonstrate a lymphoid structure around vasculature in the dura mater that can sample antigens and rapidly support humoral immune responses after local pathogen challenge.

An interactive simulator to deepen the understanding of Guyton's venous return curve.

Mean circulatory filling pressure, venous return curve, and Guyton's graphical analysis are basic concepts in cardiovascular physiology. However, some medical students may not know how to view and interpret or understand them adequately. To deepen students' understanding of the graphical analysis, in place of having to perform live animal experiments, we developed an interactive cardiovascular simulator, as a self-learning tool, as a web application. The minimum closed-loop model consisted of a ventricle, an artery, resistance, and a vein, excluding venous resistance. The simulator consists of three modules: setting (parameters and simulation modes), calculation, and presentation. In the setting module, the user can interactively customize model parameters, compliances, resistance, Emax of the ventricular contractility, total blood volume, and unstressed volume. The hemodynamics are calculated in three phases: filling (late diastole), ejection (systole), and flow (early diastole). In response to the user's settings, the simulator graphically presents the hemodynamics: the pressure-volume relations of the artery, vein, and ventricle, the venous return curves, and the stroke volume curves. The mean filling pressure is calculated at approximately 7 mmHg at the initial setting. The venous return curves, linear and concave, are dependent on the venous compliance. The hemodynamic equilibrium point is marked on the crossing point of venous return curve and the stroke volume curve. Users can interactively do discovery learning, and try and confirm their interests and get their questions answered about hemodynamic concepts by using the simulator.

[Advances in the use of neuromuscular electrical stimulation in the prevention of venous thromboembolism].

Pharmacologic prophylaxis is the most commonly used prophylaxis for venous thromboembolism (VTE), but the pharmacologic prophylaxis is limited in patients at high risk of bleeding. Mechanical prophylaxis alone or in combination is an important method of VTE prophylaxis in patients at high risk of bleeding, but the current mainstream mechanical prophylaxis, which includes graded compression stockings, intermittent inflatable compression pumps and plantar venous compression pumps, has some limitations, leading to discomfort for patients wearing them due to the large contact area, and even affecting ability to perform daily activities. Many clinical studies have found that NMES combined with pharmacological prophylaxis has better efficacy and safety than pharmacological prophylaxis alone in preventing VTE in medical and surgical patients, and the preventive effect of NMES alone is not inferior to other mechanical prophylaxis. Besides, it also has the advantages of ease of wear and patient compliance. Currently, clinicians have limited experience and knowledge of NMES. We aimed to present the rationale, progress in clinical research and future perspective of NMES in VTE prophylaxis.

Friction injury of the central vein caused by catheter for hemodialysis: an in vitro study.

Vascular injury such as central venous stenosis (CVS) is a common complication in hemodialysis patients with central venous catheters (CVCs), yet the impact of the microstructure and partial physic characteristics of catheter surface on the chronic injury of central vein has not been elucidated. In this study, the microscopic morphology of tips and bodies of six different brands of polyurethane CVCs was observed and their roughness was assessed. Subsequently, an in vitro model was established to measure the coefficients of friction (COF) between CVCs (tips and bodies) and the vena cava intima of Japanese rabbits under the same condition in a linear reciprocating mode, and changes in the intima of vessels after friction were observed. The study found that there was a significant variation in surface roughness among different brands of CVCs (tips P < 0.001, bodies P = 0.02), and the COF was positively correlated with the catheter surface roughness (tips P = 0.005, R = 0.945, bodies P = 0.01, R = 0.909). Besides, the endovascular roughness increased after friction. These findings suggest that the high roughness surface of CVCs may cause chronic mechanical friction injury to the central venous intima, which is one of the potential factors leading to CVS or occlusion. This provides a breakthrough for reducing complications, improving patient prognosis, and advancing catheter surface lubrication technology.

Differential Pacing Maneuver From the Vein of Marshall.

BACKGROUND: Bidirectional mitral isthmus (MI) block is conventionally verified by differential pacing from the coronary sinus (CS) and its sequence change. This study aimed to evaluate the ability of differential pacing from the vein of Marshall (VOM) to detect epicardial MI connections. METHODS: Radiofrequency and VOM ethanol MI ablation were performed with a VOM electrode catheter inserted to the septal side of the ablation line. MI block was verified using conventional CS pacing. To perform differential VOM pacing analysis, initial pacing was delivered from a distal VOM bipole closer to the block line, and then from a proximal VOM bipole. The intervals from pacing stimulus during different VOM pacing sites to the electrogram recorded through the CS catheter on the opposite side of the line were compared. When the interval during distal VOM pacing was longer than that during proximal VOM pacing, it indicated a VOM connection block; however, if the former interval was shorter, the connection through the VOM was considered persistent. RESULTS: Overall, 50 patients were evaluated. According to CS pacing, MI ablation was incomplete in 9 patients, in whom the analysis indicated persistent VOM connection. Among 41 patients with complete MI block, confirmed by CS finding, in 30 (73%) patients, the interval during distal VOM pacing was longer than that during proximal VOM pacing by 11±5 ms. However, in 11 patients (27%) the former interval was revealed to be shorter than the latter by 16±8 ms, indicating residual VOM connection. Conduction time across the line was significantly shorter in 11 patients than in the other 30 (166±21 versus 197±36 ms; P<0.01). Ten successful reevaluated analyses after VOM ethanol and further radiofrequency ablation of the connection indicated VOM block achievement. CONCLUSIONS: Differential VOM pacing maneuver reflects the VOM conduction status. This maneuver can uncover residual epicardial connections that are missing with CS pacing.

Impact of static foot disorders on the conservative treatment success in chronic venous disease patients without wounds.

OBJECTIVE: Chronic venous disease (CVD) and static foot disorders (SFDs) are prevalent conditions that commonly cause lower extremity pain. These conditions share common factors such as age and weight in their etiology. This study aimed to investigate the impact of SFDs on the treatment response of patients undergoing conservative treatment for CVD without wounds. MATERIALS AND METHODS: A retrospective evaluation was conducted on 328 patients (60 males, 268 females) with CVD. Parameters including age, gender, affected side, body mass index, Visual Analog Scale (VAS), Clinical-Etiological-Anatomical-Pathophysiological (CEAP) classification, and revised Venous Clinical Severity Score (rVCSS) were considered for evaluation. Radiological measurements of calcaneal pitch angle (CPA) were analyzed as a determinant of SFDs. RESULTS: VAS and rVCSS of the patients were evaluated before and after conservative treatment of CVD without concomitant treatment of SFDs. The presence of SFDs was associated with decreased treatment success (P < .001). Among different types of SFDs, the pes cavus group exhibited the lowest change in VAS and rVCSS scores before and after conservative CVD treatment. In contrast, the normal group demonstrated the highest improvement. Patients with a normal foot medial arch consistently achieved the best treatment outcomes compared with patients with other SFDs. CONCLUSIONS: In conclusion, SFDs affect outcomes of conservative treatment of CVD in CEAP 0 to 3 patients, with the efficacy of treatment dependent upon the severity of SFDs.

European and US guidelines on acute DVT management.

Acute deep venous thrombosis (DVT) is a common health problem, affecting millions of patients in Europe and the United States annually. Europe and US national clinical practice guidelines are formulated by evaluation of the available scientific evidence, with expert opinion to create pragmatic guidance for the optimal patient management, representing the best available knowledge at the time of publication, and providing the best evidence-based recommendations for vascular patient care and venous pathologies. We here focus on the novel recommendations proposed by European and US guidelines for acute DVT, denoting main differences between the two panels. This review gives vascular surgeons the opportunity to identify the key points of the two largest Vascular Committees guidelines, in order to use them and offer their best individualized treatment approach to the specific patient's anatomy, lesion, and history.

Identification of direct connections between the dura and the brain.

The arachnoid barrier delineates the border between the central nervous system and dura mater. Although the arachnoid barrier creates a partition, communication between the central nervous system and the dura mater is crucial for waste clearance and immune surveillance1,2. How the arachnoid barrier balances separation and communication is poorly understood. Here, using transcriptomic data, we developed transgenic mice to examine specific anatomical structures that function as routes across the arachnoid barrier. Bridging veins create discontinuities where they cross the arachnoid barrier, forming structures that we termed arachnoid cuff exit (ACE) points. The openings that ACE points create allow the exchange of fluids and molecules between the subarachnoid space and the dura, enabling the drainage of cerebrospinal fluid and limited entry of molecules from the dura to the subarachnoid space. In healthy human volunteers, magnetic resonance imaging tracers transit along bridging veins in a similar manner to access the subarachnoid space. Notably, in neuroinflammatory conditions such as experimental autoimmune encephalomyelitis, ACE points also enable cellular trafficking, representing a route for immune cells to directly enter the subarachnoid space from the dura mater. Collectively, our results indicate that ACE points are a critical part of the anatomy of neuroimmune communication in both mice and humans that link the central nervous system with the dura and its immunological diversity and waste clearance systems.