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Objective. Vagus nerve stimulation (VNS), which involves a surgical procedure to place electrodes directly on the vagus nerve (VN), is approved clinically for the treatment of epilepsy, depression, and to facilitate rehabilitation in stroke. VNS at surgically implanted electrodes is often limited by activation of motor nerve fibers near and within the VN that cause neck muscle contraction. In this study we investigated endovascular VNS that may allow activation of the VN at locations where the motor nerve fibers are not localized.Approach. We used endovascular electrodes within the nearby internal jugular vein (IJV) to electrically stimulate the VN while recording VN compound action potentials (CAPs) and neck muscle motor evoked potentials (MEPs) in an acute intraoperative swine experiment.Main Results. We show that the stimulation electrode position within the IJV is critical for efficient activation of the VN. We also demonstrate use of fluoroscopy (cone beam CT mode) and ultrasound to determine the position of the endovascular stimulation electrode with respect to the VN and IJV. At the most effective endovascular stimulation locations tested, thresholds for VN activation were several times higher than direct stimulation of the nerve using a cuff electrode; however, this work demonstrates the feasibility of VNS with endovascular electrodes and provides tools to optimize endovascular electrode positions for VNS.Significance. This work lays the foundation to develop endovascular VNS strategies to stimulate at VN locations that would be otherwise too invasive and at VN locations where structures such as motor nerve fibers do not exist.

Abstract Background Papillary thyroid carcinoma (PTC), being the most common thyroid malignancy, is a slow-growing tumor and is usually limited to the thyroid. Extra thyroid extension is uncommon; besides, invasion to the vasculature seems to be extremely rare and usually indicates aggressive nature of the disease. Case presentation We present a case of a 40-year-old lady who referred with a palpable neck mass a month after total thyroidectomy which its histopathologic examination revealed follicular variant of PTC; the same variant as prior thyroidectomy. Preoperative ultrasonography failed to comment on the intravascular component of the mass. Surgical procedure confirmed a mass attaching and infiltrating to the internal jugular vein, which turned out to be persistent disease. Conclusions Awareness of this entity is important for surgeons, oncologists and radiologist as it can influence patient management.

Background: Papillary thyroid carcinoma (PTC), being the most common thyroid malignancy, is a slow-growing tumor and is usually limited to the thyroid. Extra thyroid extension is uncommon; besides, invasion to the vasculature seems to be extremely rare and usually indicates aggressive nature of the disease. Case presentation: We present a case of a 40-year-old lady who referred with a palpable neck mass a month after total thyroidectomy which its histopathologic examination revealed follicular variant of PTC; the same variant as prior thyroidectomy. Preoperative ultrasonography failed to comment on the intravascular component of the mass. Surgical procedure confirmed a mass attaching and infiltrating to the internal jugular vein, which turned out to be persistent disease. Conclusions: Awareness of this entity is important for surgeons, oncologists and radiologist as it can influence patient management. [ABSTRACT FROM AUTHOR]

Intravascular lymphomas are rare disease conditions that exhibit neoplastic lymphoid cells that are confined mainly to the lumens of small capillaries and medium-sized vessels. The majority of the intravascular lymphomas are of B-cell origin, but they can include NK/T-cell and CD30+ immunophenotypes. In the histologic differential diagnosis are benign proliferations such as intralymphatic histiocytosis and intravascular atypical CD30+ T-cell proliferation. In this review, we discuss the clinical, histopathologic, and molecular findings of intravascular B-cell lymphoma, intravascular NK/T-cell lymphoma, intralymphatic histiocytosis, and benign atypical intravascular CD30+ T-cell proliferation. [ABSTRACT FROM AUTHOR]

Background: Operative hysteroscopy intravascular absorption syndrome is a little-known disease traditionally caused by the use of a hypo-osmolar distension fluid during hysteroscopic surgery. Symptoms of OHIA syndrome include pulmonary and cerebral edema, hyponatremia, and metabolic acidosis. Preventive measures include the use of a bipolar current, NaCl 0.9 ​%, and limiting positive fluid balance to 1000 ml. Case report: This paper describes the curious case of a middle-aged patient who presented to our emergency department with eye congestion, anasarca, and pulmonary edema following hysteroscopy, despite using NaCl 0.9 ​% as a distension fluid. Only a few cases have been reported in the literature, and it appears that the use of glycine instead of NaCl 0.9 ​% does not lead to the same complications. To better handle these situations, this article provides treatment suggestions and preventive measures through a literature review to help physicians to rapidly detect and manage this potentially life-threatening syndrome.Why Should an Emergency Physician Be Aware of This ? - OHIA syndrome can be life-threatening and may manifest with various complications, requiring different management approaches and complementary examinations depending on the distension fluid used by the surgeon. Physicians should be knowledgeable about this lesser-known syndrome in order to effectively prevent, diagnose, and treat it.

Background: Myopericytomas are rare tumors originating from perivascular myoid cells, with overlapping features of glomus tumors and myofibromas. Case Report: We present a case of intravascular myopericytoma, a rare variant of myopericytomas, with a mass located in the neck. This case is accompanied by a review of the relevant literature discussing its histomorphological and immunohistochemical features. In histopathology, this tumor is characterized by spindle or epithelioid cells that surround the vessels in a concentric pattern. Conclusion: While these tumors most commonly occur in extremities, they are rarely seen in the head, neck, and trunk. Even though they are generally considered benign, it's important to note that cases showing increased mitotic activity, recurrence, and metastasis have been reported. [ABSTRACT FROM AUTHOR]

Introduction: The mainstay of endovascular treatment in peripheral arterial disease is digital subtraction angiography with an iodinated contrast. In patients with a known contrast allergy, the current most commonly used alternative is to perform carbon dioxide angiography. Operator experience and availability of carbon dioxide (CO2) angiography delivery systems are, however, limited. Intravascular ultrasound is now commonly used in combination with fluoroscopy in peripheral venous interventions and in coronary arterial disease and we propose that this also provides a safe and effective alternative option to guide endovascular intervention in patients with a known contrast allergy. Case report: We present a case describing the use of intravascular ultrasound and fluoroscopy to guide endovascular treatment of a critical left common iliac artery stenosis in a patient with known anaphylaxis to iodinated contrast. Discussion: Intravascular ultrasound is fast becoming the gold standard treatment option in peripheral venous interventions; however, the use in peripheral arterial disease is limited. We believe this is the first case that reports the use of predominantly intravascular ultrasound in endovascular peripheral arterial intervention with a contrast adjunct. Conclusion: We have demonstrated that intravascular ultrasound is a safe and effective alternative or adjunct to iodinated contrast for arterial angiography and stenting in the setting of patient contra-indications. [ABSTRACT FROM AUTHOR]

BackgroundSevere injury initiates a complex physiologic response encompassing multiple systems and varies phenotypically between patients. Trauma-induced coagulopathy may be an early warning of a poorly coordinated response at the molecular level, including a deleterious immunologic response and worsening of shock states. The onset of trauma-induced coagulopathy (TIC) may be subtle however. In previous work, we identified an early warning sign of coagulopathy from the admission thromboelastogram, called the MAR ratio. We hypothesized that a low MAR ratio would be associated with specific derangements in the inflammatory response.MethodsIn this prospective, observational study, 88 blunt trauma patients admitted to the intensive care unit (ICU) were identified. Concentrations of inflammatory mediators were recorded serially over the course of a week and the MAR ratio was calculated from the admission thromboelastogram. Correlation analysis was used to assess the relationship between MAR and inflammatory mediators. Dynamic network analysis was used to assess coordination of immunologic response.ResultsSeventy-nine percent of patients were male and mean age was 37 years (SD 12). The mean ISS was 30.2 (SD 12) and mortality was 7.2%. CRITICAL patients (MAR ratio ≤14.2) had statistically higher shock volumes at three time points in the first day compared to NORMAL patients (MAR ratio >14.2). CRITICAL patients had significant differences in IL-6 (P=0.0065), IL-8 (P=0.0115), IL-10 (P=0.0316) and MCP-1 (P=0.0039) concentrations compared to NORMAL. Differences in degree of expression and discoordination of immune response continued in CRITICAL patients throughout the first day.ConclusionsThe admission MAR ratio may be the earliest warning signal of a pathologic inflammatory response associated with hypoperfusion and TIC. A low MAR ratio is an early indication of complicated dysfunction of multiple molecular processes following trauma.

BackgroundUnretrievable foreign bodies are associated with high morbidity and mortality. While the majority of reported cases involve the venous circulation, intra-arterial foreign body displacement have the potential to migrate more distally with a higher risk for dissection and hemorrhagic complications during retrieval. As the number of intravascular procedures continues to increase, there is also likely to be a concomittant increase in the number of retrieval procedures, particular for fractured catheters and sheaths. Although snaring is frequently the traditional, 'go-to' method for retrieval, there are inherent risks of further dislodgement or fracture.Case reportWe describe a case that involves retrieval of a fractured sheath that originated in the common femoral artery but migrated into the popliteal artery. Different retrieval approaches were employed, however ultimately balloon assisted, over-the-wire retrieval was the successful approach.ConclusionsWe anticipate that over-the-wire, inline-retrieval approaches will continue to grow in popularity and use, particularly with respect to manipulation within the arterial circulation.

Intravascular lymphomatosis (IVL) is a rare type of B-cell non-Hodgkin lymphoma (BCNHL), which can mimic many other diseases. Fever, neurological symptoms, and skin findings are the most frequent clinical findings. Intravascular lymphomatosis may be associated with genetic factors and infection with human immunodeficiency virus (HIV), human herpesvirus 8 (HHV-8), human T-lymphotropic virus 1 (HTLV1), Epstein-Barr virus (EBV), and hepatitis B virus (HBV). A 50-year-old man was hospitalized with recalcitrant hyponatremia of unknown cause. He had also telangiectatic, indurated, slightly erythematous plaques on his trunk for the last 10 days. His past medical history was unremarkable, although he was a carrier of hepatitis B. Multiple skin biopsies were performed and were considered to be diagnostic of IVL. The hyponatremia was unresponsive to water restriction and hypertonic solution support but it resolved with B cell directed chemotherapy. A final diagnosis was made as syndrome of inappropriate antidiuretic hormone (SIADH) in the setting of IVL. This case had a relatively early diagnosis with just 10-days of skin lesions. Intravascular lymphomatosis is a very rare disease and is usually difficult to diagnose. An even more uncommon presentation is IVL complicated by a paraneoplastic syndrome. There are prior reported cases of SIADH in the setting of IVL. However, this case underscores the importance of evaluating patients with SIADH for potential IVL.

Recent research pointed out that the degree of inflammation in the adventitia could correlate with the severity of atherosclerotic plaques. Intravascular photoacoustic endoscopy can provide the information of arterial morphology and plaque composition, and even detecting the inflammation. However, most reported work used a noncoaxial configuration for the photoacoustic catheter design, which formed a limited light‐sound overlap area for imaging so as to miss the adventitia information. Here we developed a novel 0.9 mm‐diameter intravascular photoacoustic catheter with coaxial excitation and detection to resolve the aforementioned issue. A miniature hollow ultrasound transducer with a 0.18 mm‐diameter orifice in the center was successfully fabricated. To show the significance and merits of our design, phantom and ex vivo imaging experiments were conducted on both coaxial and noncoaxial catheters for comparison. The results demonstrated that the coaxial catheter exhibited much better photoacoustic/ultrasound imaging performance from the intima to the adventitia. [ABSTRACT FROM AUTHOR]

Intravascular lymphomas are rare disease conditions that exhibit neoplastic lymphoid cells that are confined mainly to the lumens of small capillaries and medium-sized vessels. The majority of the intravascular lymphomas are of B-cell origin, but they can include NK/T-cell and CD30+ immunophenotypes. In the histologic differential diagnosis are benign proliferations such as intralymphatic histiocytosis and intravascular atypical CD30+ T-cell proliferation. In this review, we discuss the clinical, histopathologic, and molecular findings of intravascular B-cell lymphoma, intravascular NK/T-cell lymphoma, intralymphatic histiocytosis, and benign atypical intravascular CD30+ T-cell proliferation.

Background: Intravascular imaging with either intravascular ultrasound (IVUS) or optical coherence tomography (OCT) during percutaneous coronary intervention (PCI) is associated with improved outcomes, but these techniques have previously been underutilized in the real world. We aimed to examine the change in utilization of intravascular imaging-guided PCI over the past decade in the United States and assess the association between intravascular imaging and clinical outcomes following PCI for myocardial infarction (MI). Methods: We surveyed the National Inpatient Sample from 2008 to 2019 to calculate the number of PCIs for MI guided by IVUS or OCT. Temporal trends were analyzed using Cochran-Armitage trend test or simple linear regression for categorical or continuous outcomes, respectively. Multivariable logistic regression was used to compare outcomes following PCI with and without intravascular imaging. Results: A total of 2,881,746 PCIs were performed for MI. The number of IVUS-guided PCIs increased by 309.9 % from 6,180 in 2008 to 25,330 in 2019 (P-trend

Recent advances in medical imaging include integrating photoacoustic and optoacoustic techniques with conventional imaging modalities. The developments in the latter have led to the use of optics combined with the conventional ultrasound technique for imaging intravascular tissues and applied to different areas of the human body. Conventional ultrasound is a skin contact-based method used for imaging. It does not expose patients to harmful radiation compared to other techniques such as Computerised Tomography (CT) and Magnetic Resonance Imaging (MRI) scans. On the other hand, optical Ultrasound (OpUS) provides a new way of viewing internal organs of the human body by using skin and an eye-safe laser range. OpUS is mostly used for binary measurements since they do not require to be resolved at a much higher resolution but can be used to check for intravascular imaging. Various signal processing techniques and reconstruction methodologies exist for Photo-Acoustic Imaging, and their applicability in bioimaging is explored in this paper. [ABSTRACT FROM AUTHOR]

Intravascular photoacoustic imaging has been developed to evaluate the possibility of plaque rupture in atherosclerosis by high spatial resolution imaging of lipid. However, the detection sensitivity and spatial resolution are compromised by the poor focusing caused by a multimode fiber. In this work, we report an intravascular photoacoustic catheter with mode self-cleaning in a graded-index fiber to improve the beam quality and the sensitivity for lipid detection. Compared with the higher-order modes in a step-index multimode fiber, the lower-order modes generated by the self-cleaning effect in the graded-index fiber greatly enhanced the photoacoustic spatial resolution and detection sensitivity. The dominant ringing artifact caused by laser absorption of the ultrasound transducer was further reduced by using stripe suppression. A lipid plaque mimicking phantom was imaged for evaluation. Lipid particles with a small diameter of 75.7 µm were clearly observed.

The significance of basal cell carcinoma (BCC) invading the intravascular space is unknown. We report a case of an infiltrative BCC on the scalp that showed evidence of both intravascular and perineural invasion. The tumor locally recurred in the bone marrow space 4.5 years following the initial procedure. Since recurrence and metastasis of BCC can be delayed for many years, we recommend long term follow-up for tumors showing aggressive features.

Intravascular photoacoustic (IVPA) imaging is a promising modality for quantitative assessment of lipid‐laden atherosclerotic plaques. Yet, survival IVPA imaging of the same plaque in the same animal is not demonstrated. Here, using a sheathed IVUS/PA catheter of 0.9 mm in diameter, we demonstrate MRI‐guided survival IVPA imaging of same plaque in an aorta of a well‐established rabbit model mimicking atherosclerosis in human patients. The IVUS/PA results were confirmed by histology. These advances open the opportunity to evaluate the effectiveness of a therapy that aims to reduce the size of atherosclerotic plaques and demonstrates the potential of translating the IVPA catheter into clinic for detection of lipid‐rich plaques that are at high risk for thrombosis. [ABSTRACT FROM AUTHOR]

Background Aesthetic physicians rely on certain anecdotal beliefs regarding the safe practice of filler injections. These include a presumed safety advantage of bolus injection after a negative aspiration. Objectives The authors sought to review and summarize the published literature on inadvertent intravascular injection of hyaluronic acid and to investigate whether the technique of aspiration confers any safety to the practitioner and the patient. Methods Pertinent literature was analyzed and the current understanding of the safety of negative and positive aspiration outlined. Results The available studies demonstrate that aspiration cannot be relied on and should not be employed as a safety measure. It is safer to adopt injection techniques that avoid injecting an intravascular volume with embolic potential than utilize an unreliable test to permit a risky injection. Conclusions To prevent intravascular injection, understanding "injection anatomy" and injection plane and techniques such as slow, low-pressure injection are important safety measures. Assurance of safety when delivering a bolus after negative aspiration does not appear to be borne out by the available literature. If there is any doubt about the sensitivity or reliability of a negative aspiration, there is no role for its utilization. Achieving a positive aspiration would just defer the risk to the next injection location where a negative aspiration would then be relied on. Level of Evidence: 4 [ABSTRACT FROM AUTHOR]

Myopericytoma is a rare vessel wall tumor, a subtype of hemangiopericytoma that usually develops subcutaneously. Intravascular myopericytoma is a rarer subtype, with only few cases reported in the literature and even fewer with imaging modalities included. We report the case of a 36-year-old man who was referred to our institution with a painless, palpable mass in the right arm and was evaluated with MRI, grey-scale and Doppler-mode ultrasound. Tumor histopathology and imaging characteristics are presented together with the role that each imaging modality played in the management of the patient. [ABSTRACT FROM AUTHOR]

Lymphoid and haematopoietic neoplasms are rare in cetaceans. This report describes intravascular lymphoma in an adult common dolphin that presented with neurological signs prior to stranding. Intravascular lymphoma is a rare neoplasm previously recorded in humans, dogs, a cat and a horse. The condition is characterized by intravascular neoplastic lymphocytic proliferation, the sequelae of which are dependent on the organ affected. Key pathological findings in this case included multifocal cerebrocortical malacia secondary to vascular occlusion associated with intravascular neoplastic lymphocytic proliferation. Immunohistochemistry supported a T-cell phenotype similar to that observed in dogs. The neurological presentation was consistent with that seen in other species in which the central nervous system is involved. The aetiology and pathogenesis have not been established in other species and although no further investigations were made in this common dolphin, this report adds to the short list of species affected by this rare neoplasm., Competing Interests: Declaration of competing interests The authors declared no conflicts of interest in relation to the research, authorship or publication of this article., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Intravascular leiomyomatosis is a rare entity defined by benign smooth uterine muscle cells that typically originate from the uterus with the potential to spread into veins possibly up to the heart. The diagnosis for patients presenting with cardiac symptoms may be difficult and imaging often interpreted as thrombus or atrial myxoma.

Abstract Intravascular photoacoustic (IVPA) imaging is a promising modality for quantitative assessment of lipid‐laden atherosclerotic plaques. Yet, survival IVPA imaging of the same plaque in the same animal is not demonstrated. Here, using a sheathed IVUS/PA catheter of 0.9 mm in diameter, we demonstrate MRI‐guided survival IVPA imaging of same plaque in an aorta of a well‐established rabbit model mimicking atherosclerosis in human patients. The IVUS/PA results were confirmed by histology. These advances open the opportunity to evaluate the effectiveness of a therapy that aims to reduce the size of atherosclerotic plaques and demonstrates the potential of translating the IVPA catheter into clinic for detection of lipid‐rich plaques that are at high risk for thrombosis.

Optical coherence tomography (OCT) technology is a well-established diagnostic tool in multiple fields of medicine. Intravascular OCT has been used for more than a decade for the clinical imaging of coronary arteries, however, its use for the imaging of the human cerebrovasculature has been delayed by the challenges posed by the elevated vascular tortuosity. A novel high-frequency OCT (HF-OCT) probe designed for neurovascular use was evaluated in tortuous, ex vivo, human intracranial anatomy and, using an in vivo canine model, for the dynamic imaging of intracranial arteries and the subarachnoid trabecula (SAT). Using four cadavers, we investigated HF-OCT probe navigation and imaging performances in human anterior arterial circulation (from the M4 segment to internal carotid artery), in the posterior arterial circulation (from the P4 segment to vertebrobasilar junction) and in a broad range of venous sinuses. HF-OCT was able to gain distal access through elevated tortuosity and generate high-quality imaging data depicting vessel morphology, the vessel wall pathology (e.g., atherosclerotic disease and dissecting lesions), and the subarachnoid trabecula (SAT). Using an in vivo canine model, the HF-OCT probe was used to record stationary dynamic data in multiple intracranial vascular locations. Data showed the motion of the arteries and the SAT, including collisions between vessels, membranes, and the interaction between the SAT and the blood vessels. HF-OCT data allowed for the quantification of the dynamics of the vessels and the SAT, including vessel lateral motion with respect to the parenchyma, and collisions between large and small arteries. Results showed that the HF-OCT probe can overcome delivery obstacles in tortuous cerebrovascular anatomy and provide highquality and high-resolution imaging at multiple distal locations, including M4 and P4 segments of the anterior and posterior circulations. HF-OCT has the potential to facilitate a better understanding of fine anatomical details of the cerebrovascular and perivascular environment, neurovascular disease, and collect real time information about the dynamics of the subarachnoid space and arteries and become a valuable diagnostic tool. [ABSTRACT FROM AUTHOR]

Purpose: To report on the preliminary outcomes of mitomycin C (MMC) intravascular chemoembolization (MICE) for corneal neovascularization (NV). Methods: This is a retrospective case series of three consecutive eyes that underwent MICE for progressive corneal NV with sight threatening lipid keratopathy. A 1.0 cc syringe was partially filled with MMC (0.4 mg/mL) and attached to a 33-gauge needle used to cannulate the vessels. The MMC (0.01–0.05 ml) was injected with enough retrograde hydrostatic force to fill efferent and afferent vessels. Follow-up ranged from 4 months to 1 year. Results: Three eyes of three patients aged 59, 73 and 33 years were included. There were no intraoperative or postoperative complications associated with the MICE procedure. Patient 1 presented with progressive corneal NV and lipid keratopathy secondary to herpes zoster ophthalmicus (HZO) and a best-corrected spectacle visual acuity (BSCVA) of 20/100 Snellen. At one-year post-MICE, there was no recurrence (BSCVA was 20/20 Snellen). Patient 2 presented with idiopathic lipid keratopathy (BSCVA 20/50 Snellen). At four months post-MICE, there were no signs of recurrence (BSCVA 20/20 Snellen). Patient 3 presented with corneal NV and lipid keratopathy secondary to HZO (BSCVA 20/30 Snellen). At four months following two MICE treatments, resolution of the lipid keratopathy was noted (BSCVA 20/20 Snellen). Conclusions: Preliminary findings suggest that MICE may be an additional modality for treating progressive corneal NV with lipid keratopathy. Larger comparative studies with longer follow-up are warranted. [ABSTRACT FROM AUTHOR]

Percutaneous procedures to divert blood flow from one blood vessel to another can be performed with intravascular catheters but demand a method to align a crossing needle from one vessel to another. Fluoroscopic imaging alone is not adequate, and it is preferable to have a sensor on one catheter that detects the correct alignment of an incoming needle. This can be implemented by generating dipole electric fields from the crossing catheter which are detected by a receiving catheter in the target vessel and, thus, can calculate and display the degree of alignment, permitting the operator to rotate the crossing catheter to guarantee alignment when deploying a crossing needle. Catheters were built using this concept and evaluated in vitro. The results show that accurate alignment is achieved, and a successful crossing can be made. The concept is being further developed for further clinical evaluation. [ABSTRACT FROM AUTHOR]