Site Of Stenosis Research Articles

Tumor mass in the lung with superior vena cava syndrome

Group of symptoms due to vena cava superior obstruction is named superior vena cava syndrome. A 65-year-old female, long-standing smoker was presented with a two-week history of dry cough and facial swelling. The patient noticed a palpable mass on the right side of the neck. Computer tomography scan with contrast showed extensive, irregular, non-homogenous consolidation in the right upper lobe, involving the right hilus, surrounding the aortic arch, supra aortic branches and pleural effusion at the right side of the body. Also, ultrasound examination of supra clavicular space showed enlarged pathologic hypoehogenic lymph node without an echogenic hilum. Ultrasound guided fine needle biopsy of lymph node was performed, and cytopathology findings showed metastatic lesion from primary microcellular lung cancer, IIIC stadium, cT4N3M0. Venous angioplasty was performed showing stenosis in the superior vena cava. After balloon dilatation, the stent was placed at the site of stenosis. The patient received chemio- and radiotherapy and survival time was seven months. Superior vena cava syndrome is an urgent clinical condition, and lung cancer is the leading cause of this syndrome. Computer tomography imaging findings and endovascular stent placement are important for detection and management of the superior vena cava thrombosis.

Savremeni tretman pacijenata sa karotidnom stenozom

Narrowing of the carotid arteries, carotid stenosis, (CS) is a frequent manifestation of atherosclerosis. It can be associated with other diseases of peripheral blood vessels, stenotic occlusive or aneurysmal, but also coronary arteries. Almost 15% of ischemic strokes are caused by this disease, which shares common risk factors with other atherosclerotic manifestations (age, male gender, hypertension, diabetes, smoking). The disease is progressive and with progression comes the progression of the degree of stenosis, the volume and morphological characteristics of the plaque. As these features progress, they increase the risk of clinical manifestations. Ischemic stroke, transient ischemic attack or transient blindness in the ipsilateral eye (amaurosis fugax) are the only clinical manifestations that can be directly related to carotid stenosis. Ischemic changes in the brain parenchyma, which can be seen on magnetic resonance imaging or computed tomography, are also associated with carotid stenosis. All the mentioned parameters are taken into account when making decisions about further treatment. Available drug therapy includes antiplatelet and statin therapy with control of risk factors (body weight correction, smoking cessation) and associated diseases (hypertension, diabetes, etc.). Invasive treatment includes carotid endarterectomy (CEA) as vascular or carotid stenting (CAS) as endovascular treatment. KEA is performed under local or general anesthesia, increasingly under local anesthesia, and after accessing the carotid arteries through a cervicotomy, they are clamped, the flow is interrupted, and after the artery is opened, plaque removal and endarterectomy are performed. In addition to the anesthesiological management of the patient and the performance of the surgical technique, the monitoring of cerebral perfusion during clamping is an important technical detail in these operations. KAS is performed through a percutaneous transfemoral approach under local anesthesia when a stent is implanted in the carotid artery at the site of the carotid stenosis. To perform this procedure, adequate access is required in terms of the quality of the femoral and iliac blood vessels, i.e. the aortic arch. KAS was introduced into practice much later, and in the last 20 years, there has been a significant improvement both in terms of performance and technology with the development of modern stents and the materials used in their installation. A special contribution to this technique was the introduction of embolization protection. KAS is a complementary method to CEA and an individual approach to the patient enables the choice of method, taking into account the advantages and disadvantages of one and the other method. When it comes to symptomatic patients, CEA certainly has a significantly greater advantage and when the use of CAS should be avoided. Complications of both methods are general, local and neurological, with the latter being the most important. Current recommendations state that performing these procedures is beneficial for the patient if the risk of neurological complications is less than 3% in asymptomatic patients, or less than 6% in symptomatic patients. At the Clinic for Vascular and Univascular Surgery of the Clinical Center of Serbia, in the last fifteen years, almost 9.000 procedures have been performed due to carotid stenosis, of which about 10% (960) were CAS. We opt for this method in patients who are at cardiorespiratory risk for CEA or in whom access to the carotid bifurcation is difficult. All, the CEA procedures are performed under conditions of the cervical block. The improvement of patient stratification and the use of artificial intelligence should in the future help doctors decide on the method of examination and treatment of these patients.

Endovascular evaluation of intracranial atherosclerotic stenosis in a sample of Egyptian patients presented with ischemic stroke

Background and aim Intracranial atherosclerosis is an important etiology of ischemic stroke and is associated with multiple vascular risk factors. Endovascular evaluation is used for assessing patterns and distributions of intracranial atherosclerotic stenosis in a sample of Egyptian patients presented with ischemic stroke. Patients and methods A total of 50 patients with ischemic stroke or transient ischemic attack were included. Assessment of the state of cerebral vessels before the procedure was done by duplex ultrasound, magnetic resonance angiography, and/or computed tomography angiography to confirm any stenosis in intracranial vessels. Neurological assessment was done before and after the procedure using the National Institutes of Health Stroke Scale score. Digital subtraction angiography was done to evaluate the degrees and patterns of stenosis. Results A total of 50 participants (29 males and 21 females) were included. Their ages ranged from 30 to 78 years. The major risk factors were dyslipidemia (62.0%), hypertension (60.0%), diabetes mellitus (54.0%), smoking (48.0%), and atrial fibrillation (22.0%). The procedure was performed on 50 patients. A total of 39 (78.0%) patients had angiographic findings of vessel stenosis in either extracranial or intracranial vessels or both. In those 39 patients, 32 (64.0%) patients had arterial stenosis, and seven (14.0%) patients were found to have total occlusion. A total of 18 (36.0%) patients had angiographic findings of intracranial atherosclerotic stenosis. Of these 18 patients, 14 (28.0%) patients had arterial stenosis, and four (8.0%) patients were found to have total occlusion. The most common site of intracranial stenosis was middle cerebral artery (33.3%). Conclusion Endovascular evaluation of patients with ischemic stroke is yielding, informative, safe, and easy to be done.

Are There Prognostic Factors for Failure of Surgical Treatment of Post-Traumatic Posterior Ureteral Stenosis? About 30 Cases and Review of the Literature

Introduction: The management of post-traumatic stenosis of the posterior urethra is divided between early endoscopic realignment and delayed surgery. In the latter case, several techniques are used taking into account several factors. Our objective was therefore to investigate the possible prognostic factors of failure of this surgical management. Material and Methods: We conducted a retrospective study from January 2006 to December 2017 on patients admitted to the Urology Department of the Mohammed 6 University Hospital of Marrakech for management of post-traumatic posterior urethral stenosis. The parameters studied were age, medical and surgical history, causes, characteristics of the stenosis (location, number, length), associated lesions, surgical technique used, and evolution. The descriptive analysis consisted of calculation of absolute and relative frequencies for the qualitative variables, and of position and dispersion parameters for the quantitative variables (mean, standard deviation). In bivariate analysis, the comparison of categorical variables used Pearson’s Chi-square statistical test and Fisher’s test if necessary. The significance threshold was set at p < 0.05. Results: A total of 30 cases were selected. The age of our patients varied between 18 and 68 years, with an average of 38.33 years (16 - 80 years); the most affected age group was between 20 and 39 years. The mode of revelation of urethral damage was dominated by acute retention of urine present in 76% of patients, followed by dysuria (33%). The stenosis extended over 21.91 mm on average (14 - 40 mm). It was accompanied by bone involvement in 15 patients (53.3%). Erectile dysfunction was present in 23 patients (23%). Terminal urethrogram was the main surgical technique used, followed by internal urethrotomy (60% and 30% respectively). 15 patients had a recurrence, with an average of 1-second operation. Statistical analysis of the different factors studied showed no correlation with the occurrence of recurrence after surgical treatment. Conclusion: The medium and long term results of anastomotic repair of the posterior urethra do not seem to depend on the lesion parameters of the stenosis (site, number, extent, presence of associated bony lesions or erectile disorders).

Percutaneous Transluminal Angioplasty of Dysfunctional Hemodialysis Vascular Access: Can Careful Selection of Patients Improve the Outcomes?

Introduction:Our study aimed to evaluate the role of endovascular intervention in salvaging hemodialysis access in patients of end-stage renal disease with specific attention to features that may predict a poor outcome. We also evaluated the role of ultrasonography (USG) in the management of these patients.Methods:Forty-two patients with dysfunctional hemodialysis arteriovenous fistulas (AVF) were taken up for percutaneous transluminal angioplasty (PTA) with or without stent placement. All patients underwent a pre- and postprocedural USG Doppler to assess parameters such as mean flow, mean peak systolic velocity, and vessel diameter. Technical and clinical success rates were calculated, and characteristics causing increased failure rates (long-segment and multisite stenosis and diabetes) were noted.Results:The most common sites of stenosis were the anastomotic and perianastomotic sites (n = 27, 63%) on the venous side followed by distal venous drainage site (23%) and central venous stenosis (14%). The technical and clinical success rates were 98% and 92%, respectively. Three- and 6-month patency rates were 83% and 71%, respectively. Common characteristics in patients with failure (primary or secondary) were diabetes, increased age, increased length of stenosis (>2cm) and multisite stenosis. USG Doppler parameters showed a significant improvement post-PTA (P < 0.001) indicating clinical success. No major complication was noted in our study.Conclusion:PTA is successful for dysfunctional hemodialysis access. Careful selection of patients can improve the success rates and decrease economic burden in a resource-constrained country like ours. USG Doppler is essential in the assessment of iatrogenic hemodialysis AVFs.

Calcitonin gene related peptide modified mesenchymal stem cells reduce restenosis after carotid balloon injury in rats

This work aimed to investigate the effects of calcitonin gene-related peptide (CGRP)-modified mesenchymal stem cells (MSCs) on vascular stenosis in carotid balloon-injured rats. The CGRP gene labeled with EGFP was transfected into bone marrow MSCs, and CGRP protein expression in MSCs was confirmed by immunofluorescence assays. A rat carotid balloon injury model was established using a surgical method. CGRP-modified MSCs were orthotopically transplanted into the injured area of the rats. At 28 days after cell transplantation, EGFP and CD31 expression was detected by immunofluorescence staining. Hematoxylin-eosin (H&E) staining was used to detect the intima/media area of the injured carotid artery stenosis site, and the expression of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemistry. MSCs from rat bone marrow positively expressed CD29 and negatively expressed CD45. In vivo immunofluorescence staining showed that EGFP expression was significantly increased at the vascular injury site of rats transplanted with MSC_CGRP compared with the control group on the 28th day after cell transplantation and that the damaged vessels exhibited continuous CD31 expression. H&E staining showed that the vascular intimal proliferation area of rats transplanted with MSC_CGRP was significantly reduced compared with that of other groups. Furthermore, the immunohistochemistry results showed that PCNA expression in the endothelium of the MSC_CGRP group was lower than that of the other groups. Therefore, MSCs transfected with the CGRP gene can express the CGRP protein, and the implantation of CGRP-modified MSCs at the damaged site after carotid balloon-induced injury can reduce the neointimal area.

Flow volume measured by duplex ultrasound in native arteriovenous fistula for hemodialysis: a case report

Background : Native arteriovenous fistula (AVF) is the vascular access of choice for hemodialysis patients. AVF lasts longer than artificial grafts or central venous catheters. In addition, AVF has fewer complications than other vascular accesses. The use of Doppler ultrasound is used to facilitate fistula construction (vascular mapping) including AVF maturation to see if AVF can be used.&#x0D; Doppler ultrasound monitoring for maturation of AV fistulas should be monitored sonographically until the fistula is ready for use, especially when maturation is slow and in patients whose veins cannot easily be assessed by physical examination alone (eg because of obesity). The AVF DUS flow volume measurement may be the only imaging tool that can be used to monitor a fistula even during its maturation. Even so, DUS should always be done before AVF is used for the first time. This examination provides baseline data on vascular access, which can be useful in subsequent tests performed to evaluate functional problems.&#x0D; Case report : A man, 52 years old who has done AV Fitula two weeks ago. Currently patients are using a double lumen catheter (CDL) for routine hemodialysis. One day the patient had his CDL removed. Even though the patient feels thrill in the AV fistula, the nephrorologist still doubts whether the AV fistula is ripe and can be used. For this reason, a Duplex Ultrasound is performed to assess the diameter, velocity flow, PSV and TAMV .By positioning the sample volume in the presumed stenosis site, the Doppler velocity test detects a systolic peak velocity.&#x0D; Conclusion: Color flow Doppler imaging should be used as a tool to screen for areas of high velocity and to aid in the optimal placement of the pulsed Doppler sample volume. The pulsed Doppler sample volume should be set at the smallest size possible to detect discrete changes in blood flow meanwhile doppler ultrasound should be use in monitoring for maturation of AV fistulas

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Extracranial Cerebrovascular System.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Extracranial Cerebrovascular System.

Association of neurologic signs with high-field MRI findings in 100 dogs with osseous-associated cervical spondylomyelopathy.

Although osseous-associated cervical spondylomyelopathy (OA-CSM) findings have been well described using magnetic resonance imaging (MRI), there are no large-scale published studies on the associations between dog size, age, high-field MRI and neurologic findings. Using a retrospective, observational study design, we aimed to investigate an association between neurologic and high-field MRI characteristics in OA-CSM. Records were reviewed for dogs diagnosed with OA-CSM using high-field MRI. One-hundred dogs were included: 73/100 (73%) were giant breeds, 27/100 (27%) large breeds. Mean and median ages were, respectively, 3.1 and 2 years (0.3-9.75 years), with 2.6 and 2 years for giant-breed; and 4.4 and 4 years for large-breed dogs. The majority of dogs were male (75%) with chronic presentation (89%), more than one site of spinal cord compression (78%) and foraminal stenosis (91%). Dogs with multiples sites of spinal cord compression were more likely to have severe spinal cord compression (p<0.001), severe foraminal stenosis (p<0.001) and ligamentum flavum/soft tissue proliferation (p=0.03) than those with a single compressive site. There was a weak correlation between neurologic grade and severity of spinal cord compression (r=0.27; p=0.007), number of affected sites (r=0.24; p=0.0183) and spinal cord T2W hyperintensity (r=0.24; p=0.0152). Intervertebral disc degeneration was seen in 80% of dogs. Age did not appear to have a prominent role in the manifestation of OA-CSM. This study showed that OA-CSM affects a sizeable proportion of young large-breed, in addition to giant-breed dogs.

Treatment of an Unyielding Central Vein Stenosis using Valvuloplasty Balloon in a Young Female Presenting with Ineffective Hemodialysis

Abstract Percutaneous balloon venoplasty is widely employed for the management of central vein stenosis (CVS), a condition frequently encountered in patients on maintenance hemodialysis (MHD). The hypertrophied and fibrotic venous stenotic lesions often pose a challenge for interventionists, due to resistance to dilatation and high-elastic recoil. We report here successful utilization of mitral valvuloplasty balloon for percutaneous treatment of an unyielding brachiocephalic vein stenosis. Repeated failure of conventionally used peripheral balloon dilatation catheter prompted the use of a mitral valvuloplasty balloon that could exert higher radial pressure while preventing melon-seeding and hence successfully achieve stenosis dilatation. The mitral valvuloplasty balloon can be effectively and safely used for lesions resistant to repeated dilatations by conventional peripheral balloons. Rheological stress on central veins from ipsilateral arteriovenous fistula (AVF) may result in development of stenotic lesions, even in the absence of prior venous catheterization of the affected vein; therefore, in the presence of relevant symptoms, this diagnosis should not be excluded on the basis of absence of prior direct trauma at the stenosis site.

Subtypes, Risk Factors and Site of Stenosis of Ischaemic Stroke in a University Hospital in Bangladesh

Stoke is the second most common cause of death and the most common cause of adult disability. To plan an efficient evaluation and treatment of an individual patient with ischaemic stroke, the clinician should be familiar with the subtyping of ischaemic stroke patients and the risk factors analysis of different aetiology. Eight hundred seventy-seven (877) patients have been selected for this cross-sectional study conducted in a university hospital of Bangladesh from 2014 to 2018, to whom brain imaging [Computed Tomography (CT)/ Magnetic Resonance Imaging (MRI)], vascular imaging [Magnetic Resonance Angiogram (MRA), Digital Subtraction Angiogram (DSA)], ECG and echocardiography have been done. We did subtyping according to TOAST criteria. The mean age of patients was 60.5 ± 11 years. Most patients (29.33%) belonged to the age group 51 – 60, where 70.47% of subjects were male and 29.53% were female. In this study, 43.87% of patients were in the large artery atherosclerosis group, 23.83.% in the small vessel occlusion group, 8.46% in the cardiac embolism group, 19.30% in the undetermined aetiology group and 4.54% in other determined aetiology. Among risk factors hypertension, diabetes mellitus, dyslipidaemia was present in 58.15%, 38.42%, and 38.88% of patients, respectively. In ischaemic stroke patients, large artery atherosclerosis was the most common subtype and hypertension was significant in this group. Extracranial stenosis was more common in ischaemic stroke.

P524 Endoscopic dilations of intestinal stenosis in Crohn’s disease

Abstract Background The occurrence of intestinal stenosis is a common and potentially serious complication of Crohn’s disease (CD). These strictures represent 20% of the surgical indications in CD. Endoscopic dilation is an alternative to surgery for endoscopically accessible stenosis. The aim of this study is to evaluate the effectiveness of endoscopic balloon dilation (EBD) in CD intestinal stenosis. Methods This retrospective, descriptive study realized between January 2015 and October 2020, included CD patients diagnosed at least 6 months before and complicated with symptomatic intestinal stenosis (abdominal pain, bloating, nausea and vomiting). Anorectal strictures were excluded. All patients had a cross-sectional imaging before intestinal dilation to determine the characteristics of the stenosis and exclude abscess and fistula tract near the stenosis which constitute a contraindication of EBD. All patients underwent an EBD during a colonoscopy under sedation by propofol. The short-term success of EBD has been established on both technical (passage of the endoscope across the site of stenosis after dilation) and clinical level (relief of intestinal obstructive symptoms). The long-term efficacy was defined by no need for surgery within 6 months after dilation. Results Twelve patients (6 males and 6 females), with an average age of 32 years +/-7.7, were included. The average interval between onset of CD and the onset of intestinal stricture was 8 years. Eight patients had a history of bowel resection. The stenosis was located at the terminal ileum or ileocaecal valve in 4 cases, ileocolic anastomosis in 8 cases. The stenosis was ulcerated in 9 cases, inflammatory in 5 cases and polypoid in 3 cases. All patients were on medical treatment corticosteroids, Azathioprine and / or Anti TNF. We performed 18 EBD, divided into several sessions depending on the degree of stenosis (1 EBD, 2 EBD and 3 EBD in respectively 11, 3 and 2 patients). Two patients required surgery for persisting symptoms. Technical success was obtained in 11 patients (92% of cases). Clinical success, defined by a disappearance of clinical symptoms with an HBI score of less than 4, was obtained in 9 patients (75% of cases). The mean follow-up after dilation was 23 months (range from 8 to 42 months). No major complications were observed in this study. Conclusion EBD is an effective therapeutic technique relatively safe for intestinal CD stenosis, allowing to delay or better, to avoid surgical treatment when the stenosis is well selected (stenosis&amp;lt;4cm, single, anastomotic, non-angled, and without adjacent abscess or fistula).

Direct CT Venography in ESRD Patients: Technical Experience and Findings

Objective: The aims of this study were to describe direct computed tomography venography (CTV) for upper limb venous system evaluation and to report on findings in end-stage renal disease (ESRD) patients.Materials and Methods: Direct CTV was performed using a 64-multidetector computed tomography (MDCT) scanner with simultaneous injection of diluted iodinated contrast (IC); 1:4 at both elbows and 2-phase scanning namely, the direct venous, and the arterial phases. The findings in ESRD patients evaluated between November 2013 and March 2019 were retrospectively reviewed.Results: Forty CTV examinations (600 venous segments) were performed and the volume of IC used per patient was 38 mL. Number of lesions found in a patient ranged from 1 to 6 and the majority had 1 to 3 lesions (30/38 patients). Stenosis and thrombosis were the two most common findings (112/600) and were equally prevalent. The three most common sites of steno-occlusive complications were the brachiocephalic vein (29 lesions), the internal jugular vein (25 lesions), and the subclavian vein (16 lesions). The most common site of stenosis was the brachiocephalic vein (18 lesions), whereas the most common site of thrombosis was the internal jugular vein (20 lesions). No venous aneurysms or ruptures were found. IC extravasation at the site of injection occurred in one arm in one patient.Conclusion: Direct CTV has the advantage of requiring lower IC volume while maintaining direct visualization of the venous system similar to conventional venography.

Intraoperative navigation during atresiaplasty for congenital aural atresia

ObjectiveThe purpose of this study was to evaluate the feasibility of intraoperative navigation (ION) using adhesive fiducials and high-resolution computed tomography (HRCT) of the temporal bone in pediatric patients undergoing atresiaplasty for congenital aural atresia (CAA). MethodsFrom June 2018 to August 2019, a retrospective review was performed on pediatric patients with unilateral or bilateral CAA who underwent atresiaplasty with or without concurrent bone anchored implant (BAI) placement. Single stage atresiaplasty was performed at a tertiary referral center with ION linked to image-guidance compatible HRCT non-contrast temporal bone images. Up to six adhesive fiducials were placed for navigation. Patient demographics were collected including Schuknecht classification type and Jahrsdoerfer score. Main outcome measures included the number of useable adhesive fiducials for navigation, navigation system registration accuracy, operative time, intraoperative complications, and postoperative outcomes including facial nerve function, surgical site infection rate, restenosis rate, and audiometric data. ResultsFive patients (3 male, 1 AU atresia, 2 AS atresia, all Schuknecht type C) with an average age of 9.2 years (range 6.8–11.8 years) underwent single sided atresiaplasty with ION. Two patients underwent concurrent BAI placement. Average Jahrsdoerfer score was 8.6 (range 7–10). Preoperative audiogram demonstrated a mean air-bone gap (ABG) of 45 dB (range 35–54 dB). The navigation system registration accuracy ranged from 0.08 to 1.80 mm (mean 1.00 mm). Mean operative time was 268 min (range 217–307 min). There were no intraoperative complications. At an average follow up of 7.2 months (range 2–15 months), postoperative facial nerve function was normal in all patients and no patients developed postoperative stenosis or surgical site infections. Four patients underwent postoperative audiogram at an average of 4 months after surgery (range 2–5 months) and all demonstrated an ABG of less than 30 dB (mean 20 dB, range 15–26 dB) with an average improvement in ABG of 23 dB (range 11–39 dB). The one patient who did not undergo postoperative pure tone audiometry underwent AzBio speech perception testing and demonstrated an improvement from 81% to 89%. ConclusionsThe use of ION in otologic surgery is uncommon. Inherent aberrant temporal bone anatomy in CAA makes this a unique population to study the value of this technology. The use of adhesive fiducials is feasible, with navigation registration accuracy and surgical outcomes comparable to those in the literature. More data is necessary regarding the impact of ION on long-term surgical and audiometric outcomes.

Evaluation of intravascular therapy for cerebral ischemic tandem stenosis

Objective: To investigate the efficacy and the safety of intravascular therapy for cerebrovascular ischemic tandem stenosis. Methods: Clinical data of 35 patients with symptomatic anterior circulation and posterior circulation tandem stenosis who received intravascular therapy for two sites of stenosis at the same time at Department of Neurosurgery of Peking University First Hospital from January 2013 to December 2018 were analyzed retrospectively. There were 27 males and 8 females,aged (65.6±9.4)years (range:47 to 81 years).There were 14 cases of anterior circulation tandem stenosis and 21 of posterior circulation tandem stenosis.The medical records were collected with emphasis on postoperative symptoms,imaging manifestations and modified Rankin scale(mRS) scores. Results: Sixty-eight stents were implants in to 35 patients,including 49 extracranial implants and 19 intracranial implants.The surgical success rate was 100%.The perioperative death rate was 0,and 1 patient(1/35,2.9%) had cerebral hemorrhage.All patients were followed up for 18 months.During 3 to 12 months after the intervention,1 case(1/35,2.9%) had stent restenosis,and 4 cases(4/35,11.4%) had persisted symptoms such as dizziness and weakness in limbs.All patients'mRS scores were ≤2. No new stroke occurred. During 12 to 18 months after the intervention,3 cases had in-stent restenosis,increasing the rate to 11.4% (4/35). The mRS scores of 32 patients(32/35,91.4%) were ≤2. Conclusion: Intravascular therapy for patients with symptomatic tandem stenosis is a feasible and safe procedure with good short-term outcomes.

THE CASE OF THE ACUTE MYOCARDIAL INFARCTION AT THE CONGENITAL ANOMALY OF THE HEART – THE MYOCARDIAL BRIDGE

Muscle bridges in the human heart are benign developmental abnormalities that can lead to acute myocardial ischemia. Muscular myocardial bridges are often found in the region of the anterior interventricular artery, while the diameter of the coronary artery before the bridge is larger than after it. The gold standard for detecting this pathology is coronary angiography, which allows visualizing the internal contours of the coronary artery. The study makes it possible to give a qualitative assessment of the site of stenosis with the determination of the cause of its occurrence. Angiographic signs of this pathology can include curvature of the segment of the affected coronary artery, uniform narrowing of the vessel lumen by more than 40% in systole and restoration of the diameter in diastole, clear signs of narrowing in at least two angiographic views, absence of vasoconstriction caused by pharmacological agents or a catheter. The aim of the study was to conduct a clinical and anatomical analysis of a case of acute myocardial infarction of type 2 caused by an anomaly in the development of the anterior interventricular artery. The analysis used data from the medical history, the results of intravital laboratory and instrumental studies, qualitative and quantitative morphological studies of the heart obtained during autopsy. The results of the study describe in detail at the macroscopic and microscopic levels the analyzed case of myocardial infarction against the background of an anomaly in the development of the anterior interventricular artery. The deceased patient has a history of comorbid pathology - myeloma. The authors suggest that an anomaly in the development of one of the branches of the left coronary artery in the form of a myocardial bridge and myeloma were pathogenic factors in the development of type 2 myocardial infarction of the anterior wall of the left ventricle. The immediate cause of death of the patient was acute left ventricular failure with pulmonary edema.

Endothelial Shear Stress and Platelet FcγRIIa Expression in Intracranial Atherosclerotic Disease.

Intracranial atherosclerotic disease (ICAD) has been characterized by the degree of arterial stenosis and downstream hypoperfusion, yet microscopic derangements of endothelial shear stress at the luminal wall may be key determinants of plaque growth, vascular remodeling and thrombosis that culminate in recurrent stroke. Platelet interactions have similarly been a principal focus of treatment, however, the mechanistic basis of anti-platelet strategies is largely extrapolated rather than directly investigated in ICAD. Platelet FcγRIIa expression has been identified as a potent risk factor in cardiovascular disease, as elevated expression markedly increases the risk of recurrent events. Differential activation of the platelet FcγRIIa receptor may also explain the variable response of individual patients to anti-platelet medications. We review existing data on endothelial shear stress and potential interactions with the platelet FcγRIIa receptor that may alter the evolving impact of ICAD, based on local pathophysiology at the site of arterial stenosis. Current methods for quantification of endothelial shear stress and platelet activation are described, including tools that may be readily adapted to the clinical realm for further understanding of ICAD.

Contribution of atherosclerotic plaque location and severity to the near-wall hemodynamics of the carotid bifurcation: an experimental study and FSI modeling.

Atherosclerosis is initiated by endothelial injury that is related to abnormal values of hemodynamic parameters such as wall shear stress (WSS), oscillatory shear index (OSI) and stress phase angle (SPA), which are more common in arterial bifurcations due to the complex structure. An experimental model of human carotid bifurcation with accurate geometrical and mechanical features was set up, and using realistic pulsatile flow rates, the inlet and outlet pressure pulses were measured for normal and stenosed models with 40% and 80% severities at common carotid (CCA), internal carotid (ICA) and external carotid (ECA) arteries. Based on the obtained experimental data, fluid-structure models were developed to obtain WSS, OSI, and SPA and evaluate pathological consequences at different locations. Mild severity had minor impact, however, inducing severe 80% stenosis in each branch led to considerable localized changes of hemodynamic parameters both in the stenosis site and other locations. This included sharp increases in WSS values accompanied by very low values close to zero before and after the peaks. Severe stenosis not only caused significant changes in the local artery, but also in other branches. OSI and SPA were less sensitive to stenosis, although high peaks were observed on bifurcation site for the stenosis at ECA. The interconnection of arteries at carotid bifurcation results in altered pressure/flow patterns in all branches when a stenosis is applied in any site. Such effect confirms pathological findings that atherosclerotic plaques are observed simultaneously in different carotid branches, although with different degrees of plaque growth and severity.

Arteriovenous shunt stenosis assessment based on empirical mode decomposition and 1D-convolutional neural network: Clinical trial stage

Patients suffering from end-stage renal disease usually receive dialysis therapy. The arteriovenous (AV) shunt is a vital vascular access for achieving sufficient blood flow in the vein during hemodialysis and can be either an arteriovenous fistula (AVF) or an arteriovenous graft (AVG). However, the lumens of dialysis accesses are frequently narrowed by thrombosis, resulting in stenosis at the venous anastomosis site or progression of inflow stenosis at the arterial anastomosis site. A narrowed vascular wall will produce abnormal physical stress and cause turbulent flow and high blood pressure. Hence, murmur sounds will occur around the stenotic site. The auscultation method is a noninvasive technique to detect these sounds as phonoangiograph (PAG) signals. The empirical mode decomposition (EMD) method is used to decompose intrinsic fast and slow oscillation components from PAG signals. In this study, the slow oscillation component containing key spectral energy distributions (< 100, 100–300 Hz, and > 300 Hz) will be used to identify the normal and abnormal conditions for further stenosis level assessment. After extracting key frequency-based features using EMD, 1D convolutional and pooling processes, feature patterns can be extracted from spectral patterns, which can distinguish distinct feature patterns and reduce the dimensions of feature patterns and the number of feature datasets for training the classifier. Next, a convolutional neural network-based classifier is used to assess the stenosis levels at a near venous anastomosis site. Its model can solve nonlinear mapping applications and nonlinear separable classifications, including the normal condition, AVG stenosis, and AVF stenosis. The experimental tests with cross-validation will indicate that the proposed method provides a promising result in clinical trials, including mean recall (%), mean precision (%), mean accuracy (%), and a mean F1 score of 95.35 %, 89.49 %, 86.82 %, and 0.9232, respectively, by offering an automatic procedure for AV shunt stenosis assessment without the need for manual feature extraction and classification.

Effect of Nanobubble-Based Ultrasound Imaging Technology on the Treatment of Ureteral Stenosis.

In order to explore the effect of nanobubble-based ultrasound imaging technology on the treatment of ureteral stenosis, a total of 120 patients, who were confirmed as ureteral stenosis by surgery, pathology or multiple imaging examinations at a designated hospital of the study from December 2015 to December 2018, were selected as research objects and were divided into three groups of targeted nanobubble (TN) group, blank nanobubble (BN) group and control (CT) group with 40 cases in each group. The TN group utilized the nanobubbles with a particle size of (499.52±72.87) nm as carriers to compare and analyze patients' ultrasound images for the predisposition and etiology of ureteral stenosis and the sonogram variations of hydronephrosis, renal pelvis; the BN group utilized the blank nanobubble with a particle size of (446.71±45.36) nm as carriers to perform ultrasound imaging and diagnostic analysis of ureteral stenosis; the CT group directly conducted ureteral stenosis treatment with ultrasound imaging technology. The results showed that the total coincidence rates of the targeted diagnosis for ureteral stenosis of the TN, BN and CT group were 94.38%, 87.52%, and 67.94%, respectively; the coincidence rates of different examination methods for different diagnostic parts were different and the diagnostic coincidence rates of TN group for pelvic ureteral transition area, end of ureter, and the area between pelvic ureteral transition area and end of ureter were 82.91%, 79.66%, and 75.17%, respectively; the diagnostic coincidence rates of BN group for those were 80.32%, 94.77%, respectively and 92.18% and the CT group were 58.66%, 72.14%, and 66.48%, respectively; the diagnosis coincidence rates for ureteral stenosis etiology of the TN, BN and CT group were 93.81%, 82.66% and 64.57%, respectively. Therefore, it was believed that the nanobubble-based ultrasound examination can accurately diagnose the site of ureteral stenosis through the exploration of hydronephrosis and ureteral dilatation with the advantages of simplicity, no pain, repeatable examination, and no impact on renal function, and having high clinical value for diagnosing ureteral stenosis.