Distal Branches Research Articles

Investigating the impact of APOE4 genotype on the association between cerebral blood flow and haematological properties in mid‐life adults

AbstractBackgroundCarriership of the apolipoprotein ε4 (APOE4) allele confers a heightened risk for the development of Alzheimer’s disease (AD). Cerebral blood flow (CBF) is decreased in prodromal and established AD, however findings in the preclinical stage are mixed, with some studies reporting increases. CBF can be impacted by many factors including the haematocrit. We investigated in a cohort at risk of developing AD how haematological variables relate to CBF and if this relationship is differentially moderated by APOE4.Method375 participants from the PREVENT‐Dementia study underwent arterial spin labelling (ASL) and structural 3Tesla MRI. ASL data were analysed using BASIL/FSL and structural scans with SPM12. CBF maps were corrected for partial volume effects. A vascular territory mask with nine territories, the middle, proximal and distal branches of the anterior, middle and posterior cerebral arteries (ACA, MCA, PCA) was used for region‐of‐interest analysis and registered to the native ASL space. Regional gray matter (GM) CBF values were harmonised using COMBAT. Linear regression was used to examine differences between APOE4 carriers and non‐carriers controlling for age, sex and years of education. Associations between haematological properties and CBF were examined with Pearson’s correlations. Differential relationships between CBF, haematocrit, and measures of red blood cell size and shape (distribution width (RDW) and mean corpuscular volume (MCV)) were investigated by including interaction terms of APOE4 and haematological variables in the models.ResultAPOE4 carriers had significantly higher CBF in the proximal MCA (t = 2.54, p = 0.01). Across all subjects, RDW and MCV were not associated with GM CBF, though several significant interactions were observed between APOE4 and RDW in predicting CBF (Figure 1). Haematocrit was associated with GM CBF (ρ = ‐0.19, p < 0.01). No significant interactions were seen between APOE4 and haematocrit or MCV in predicting CBF.ConclusionThe variability of the size and shapes of erythrocytes was differentially associated with CBF between APOE4 carriers and non‐carriers suggesting a different response to morphological erythrocyte alterations. This could further relate to underlying factors such as inflammation, which is associated with a higher RDW. Such associations should be examined in further studies.

Investigating the impact of APOE4 genotype on the association between cerebral blood flow and haematological properties in mid‐life adults

AbstractBackgroundCarriership of the apolipoprotein ε4 (APOE4) allele confers a heightened risk for the development of Alzheimer’s disease (AD). Cerebral blood flow (CBF) is decreased in prodromal and established AD, however findings in the preclinical stage are mixed, with some studies reporting increases. CBF can be impacted by many factors including the haematocrit. We investigated in a cohort at risk of developing AD how haematological variables relate to CBF and if this relationship is differentially moderated by APOE4.Method375 participants from the PREVENT‐Dementia study underwent arterial spin labelling (ASL) and structural 3Tesla MRI. ASL data were analysed using BASIL/FSL and structural scans with SPM12. CBF maps were corrected for partial volume effects. A vascular territory mask with nine territories, the middle, proximal and distal branches of the anterior, middle and posterior cerebral arteries (ACA, MCA, PCA) was used for region‐of‐interest analysis and registered to the native ASL space. Regional gray matter (GM) CBF values were harmonised using COMBAT. Linear regression was used to examine differences between APOE4 carriers and non‐carriers controlling for age, sex and years of education. Associations between haematological properties and CBF were examined with Pearson’s correlations. Differential relationships between CBF, haematocrit, and measures of red blood cell size and shape (distribution width (RDW) and mean corpuscular volume (MCV)) were investigated by including interaction terms of APOE4 and haematological variables in the models.ResultAPOE4 carriers had significantly higher CBF in the proximal MCA (t = 2.54, p = 0.01). Across all subjects, RDW and MCV were not associated with GM CBF, though several significant interactions were observed between APOE4 and RDW in predicting CBF (Figure 1). Haematocrit was associated with GM CBF (ρ = ‐0.19, p < 0.01). No significant interactions were seen between APOE4 and haematocrit or MCV in predicting CBF.ConclusionThe variability of the size and shapes of erythrocytes was differentially associated with CBF between APOE4 carriers and non‐carriers suggesting a different response to morphological erythrocyte alterations. This could further relate to underlying factors such as inflammation, which is associated with a higher RDW. Such associations should be examined in further studies.

Impact on hemodynamics in carotid arteries with carotid webs at different locations: A Numerical Study Integrating Thrombus Growth Model

ObjectiveCarotid webs (CWs), lesions in the carotid arteries, are gaining research interest due to the unclear link to ischemic stroke. Similarity to atherosclerosis in lesion location adds the complexity. The main purpose of study is to investigate the hemodynamic effects of CWs at different locations in carotid arteries. MethodsThree types of models with CWs were reconstructed from the CTA dataset of 8 healthy carotid arteries (Models A: CWs at the common carotid artery; B: at the origin of internal carotid artery; C: at the carotid sinus). Wall shear stress (WSS)-based parameters, including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT), and endothelial cell activation potential (ECAP) were analyzed. A thrombus growth model was also incorporated to assess long-term thrombus formation across different carotid webs locations. ResultsModels A exhibited helical flow, whereas models B and C showed disturbed flow in the carotid sinus. Recirculation in Models A and B was mainly downstream of CWs, while Models C had both upstream and downstream recirculation. In addition, models A had higher overall TAWSS levels, with the smallest region of TAWSS < 0.4 pa (7.78 ± 8.35%). In contrast, Models C had larger areas with TAWSS < 0.4 pa, RRT > 100, and ECAP > 1.5, accounting for 14.18 ± 5.28%, 1.51 ± 1.17%, and 10.36 ± 4.10%, respectively. Noting that thrombus volume was highest in Models C (7.20 ± 3.95%). ConclusionsNumerical simulations indicate that: 1) CWs have less hemodynamic impact when located in the CCA, but may increase flow resistance leading to distal branch ischemia; 2) CWs contribute to thrombus formation, primarily downstream in the common carotid artery and internal carotid artery origin, and both upstream and downstream in the sinus; 3) CWs at the origin of the ICA are more likely to result in disturbed blood flow patterns and thrombus aggregation than the other two locations, which may increase the risk of ischemic stroke in distal cerebral arteries.

SURG-30. CLINICAL CONSIDERATIONS, APPROACH SELECTION, AND OUTCOMES ASSOCIATED WITH TREATMENT STRATEGIES FOR FALCOTENTORIAL MENINGIOMAS: SYSTEMATIC REVIEW AND META-ANALYSIS OF THE CURRENT EVIDENCE

Abstract INTRODUCTION Meningiomas at the falcotentorial (FT) junction are rare, as they account for only 0.3%-1.1% of all intracranial meningiomas. Clinical management of FT meningiomas can be challenging. METHODS The authors queried three databases per PRISMA guidelines to identify all studies reporting indications for surgical resection of FT meningioma. RESULTS Thirty studies reporting 224 FT patients met pre-specified inclusion criteria. Patients diagnosed with FT meningioma demonstrated a predilection for headache on initial examination (p = 0.030).Headache was the mostly commonly reported symptom, present more often than visual disturbance (RR 2.28 [1.59, 3.26], I2=0%, P &amp;lt; 0.00001), ataxia or imbalance (RR 0.21 [0.08, 0.35], I2= 0%, P = 0.002), and cognitive disturbance (RR 0.34 [0.20, 0.47], I2 = 12%, P &amp;lt; 0.00001). An overwhelming majority of lesions (n = 97, 80.2%) were benign, WHO Grade I. The primary arterial feeders supplying the FT lesions were reported in 13 studies; most commonly, these arterial feeders included the distal branches of the ICA (n = 29), ECA (n = 25), and vertebrobasilar vasculature (n = 35). Visual deficits (n = 32, 14.3%) were the most common postoperative complication.Bassiouni classification of the tumors was reported in 10 studies, with 27 (31.8%) classified as type I, 16 (18.8%) as type II, 37 (43.5%) as type III, and five (5.9%) as type IV FT meningiomas.Simpson Grade I resection (n = 76, 43.7%) was achieved in slightly less than half of cases. Cases involving multi-stage resections appeared to confer greater risk (RR 1.42 [0.72, 2.80], I2=0%, P = 0.31) for STR (failure to achieve GTR or Simpson Grade I resection). CONCLUSION The primary objective when treating FT meningiomas is to achieve gross total resection (GTR) or Simpson Grade 1 resection. Grade 2 resection is also regarded as a good outcome for these lesions. This goal should be pursued while minimizing cerebellar retraction and protecting vital vascular structures, such as the Galenic venous system.

Abstract 093: Carotid Stump Syndrome: an Insidious Source of Recurrent Ischemic Strokes

Introduction Carotid stump syndrome (CSS) is a paradoxical phenomenon that occurs when there are repeated ischemic events in the carotid vascular territory despite demonstrated occlusion of the ipsilateral internal carotid artery (ICA). It is thought to be caused by turbulent blood flow in the patent stump of the occluded ICA creating microemboli which reach the brain through anastomotic channels and retrograde flow. We present a case of recurrent infarctions in setting of known ipsilateral ICA occlusion, who was diagnosed with carotid stump syndrome. Methods A male veteran in his 60s with a medical history of DVTs on apixaban, PVD, and ischemic stroke with residual right‐sided weakness, presented with worsening right‐sided weakness and difficulty with ambulation. Two months prior to the presentation he was diagnosed with acute infarcts in left frontal, parietal, and temporal lobes due to thromboembolism from left ICA occlusion. On presentation his neurological exam revealed right‐sided hemiparesis. MRI brain showed multiple acute and chronic cortical and subcortical infarcts in the left frontotemporoparietal lobes and lack of flow void in the left distal ICA. To further evaluate the dynamics of blood flow patient underwent a cerebral angiogram which confirmed the diagnosis of complete occlusion of left ICA and demonstrated reconstitution of the intracranial ICA through retrograde filling via the ophthalmic artery and anastomotic branches with the internal maxillary artery (IMax). For secondary prevention he was started on statin and aspirin while his home Apixaban was continued. Surgical and endovascular treatment approaches were discussed but the patient declined any intervention. In his four months follow up clinic visit he had no further concerns of recurrent strokes or new symptoms. Results Carotid stump syndrome is a rare cause of cerebral and retinal ischemia; however, it must be considered in patients with recurrent ischemic strokes and chronic ipsilateral ICA occlusion. Due to the patent proximal, or perhaps in some cases distal, carotid stump, there’s turbulent flow and hence the thrombus formation can occur. Hemodynamic and embolic factors attribute towards the microembolization from the proximal carotid stump through the external carotid artery (ECA), into the facial artery and IMax and their distal branches which anastomose with the ophthalmic artery, causing the emboli to end up in the major branches of the carotid terminus. If a distal stump is symptomatic, then the microemboli can readily end up in the distal ICA branches. In addition to medical management with DAPT or anticoagulation and high intensity statin, our literature review supports endovascular or surgical interventions due to reportedly good outcomes. Interventional approaches may include ECA‐ICA stenting with a covered stent or stent‐assisted coil embolization of the proximal stump. Surgical procedures include an endarterectomy on the ipsilateral ECA or contralateral ICA to increase collateral circulation. ECA‐ICA bypass is another option. Conclusion Carotid stump syndrome is a rare and underrecognized cause of recurrent ischemic strokes, though it is a potentially treatable entity. The therapeutic goals include medical management along with endovascular or surgical treatment whenever possible.

Abstract 139: Super Distal Access using the Vecta46 Intermediate Catheter in Embolization of the MMA for cSDH

Introduction There is increasing literature to support the efficacy of middle meningeal artery (MMA) embolization in the treatment of chronic subdural hematomas (cSDH). Techniques for optimal embolization of the MMA are yet to be elucidated. We hypothesized utilization of a novel 046” intermediate catheter within the proximal MMA trunk carry procedural advantages for multiple pedicle embolizations and ease of navigation to distal MMA vasculature. Methods We retrospectively reviewed and analyzed a prospectively maintained IRB‐approved database of the senior authors. Results Twenty‐one (21) consecutive cases of Vecta46 utilization with MMA embolization were identified (2023), in patients 69±13 years (range 49‐83 years), 4 (19%) women. Four (19%) patients were on antiplatelet/anticoagulants. At presentation, recurrent cSDH in 9 patients (43%) were previously managed with burr holes (n=2, 22%), craniotomy (n=3, 33%), or without drainage (n=4, 44%). Average admission cSDH thickness was 8.8±1.6mm, midline shift of 3±0.7mm. Access was performed through a 5‐ or 6‐French arteriotomy. Both anterior and posterior MMA branches were embolized in 16 (76%) cases, and adjunctive coiling of the proximal MMA trunk was performed in all cases. Vecta46 was successfully placed in the proximal MMA trunk in all cases. There were no vessel irregularities, vasospasm, or dissection noted along the course of the MMA Vecta46 placement. No immediate procedural complications were noted and all cases achieved complete distal MMA occlusion. Figure 1: (A) Ophthalmic (black) and petrous (white) collaterals off the anterior and posterior MMA branches, respectively. (B) Contralateral (green) and falx (orange) penetration of the MMA branches. (C) Proximal coiling of the anterior and posterior MMA branches (black). Conclusion The Vecta46 intermediate catheter is a powerful tool for MMA embolization that allows the safe and effective placement of an intermediate catheter in the proximal MMA trunk. This allows for simple catheter exchange for multiple liquid embolic pedicle embolizations and significant support for navigating microcatheters to distal MMA branches.

Abstract 191: Simulating Intracranial Stenosis: A Methodological Approach In An In‐Vitro Neurovascular Model

Introduction Intracranial atherosclerotic disease (ICAD) induces the luminal narrowing of an intracranial vessel and represents one of the major causes of ischemic strokes [1, 2, 3, 4]. In vitro 3D printed models have gained popularity in the stroke research field as they are morphologically accurate and offer the possibility to simulate clinical scenarios for training purposes or device testing. Despite being a challenge for interventionalists, to date, clinically accurate ICAD in vitro models have not been developed. We aimed to develop a 3D printed ICAD model including realistic features to provide an optimal simulation phantom for research and training purposes. Methods Stereolithography 3D printing technique was used to create a resin neurovascular model based on vascular anatomies extracted from anonymized CTA images. The phantom includes the aortic arch, all supraoptic cervical arteries and a complete circle of Willis up to the M2‐MCA, A2‐ACA and P2‐PCA segments. 3% sodium alginate solution was cast into a stenosis mold and crosslinked in a 40% calcium chloride. The deformable gel constituted an 8mm long replaceable stenotic segment at the level of M1‐MCA simulating an atherosclerotic plaque with a 0.5mm internal diameter. A flow sensor (ME‐8PXL, Transonic) was used to measure the lesion flow rate before and after endovascular treatment was performed under fluoroscopy. Results The baseline angiographic run showed an irregular 80% stenosis at the level of M1‐MCA that generated a substantial delay of contrast arrival to the distal branches. After angioplasty (Gateway PTA Balloon Catheter 3.5x20mm, Boston Scientific) and stenting (Wingspan 2.5mmx15mm, Stryker) were performed the residual stenosis was &lt;10% (Figure 1). An initial stenosis flow rate was registered with a value of 8.5 ± 5.33 mL/min. Following the completion of the endovascular procedure, the flow sensor detected a post‐procedural stenosis flow rate of 160 ± 3.45 mL/min. Conclusion The developed ICAD model is anatomically accurate and offers realistic physiological and procedural features. The phantom represents an ideal tool for training purposes and a platform to test different devices for the endovascular treatment of ICAD. The methodology and materials could be applied to simulate stenotic lesions at different levels in the cervical and intracranial arteries.

Abstract 104: Fetal Posterior Cerebral Artery (PCA) Occlusion from Occluded Cavernous ICA Stent

Introduction Posterior Cerebral Artery (PCA) is a medium vessel occlusion (MVO) which is 5‐10% of all acute ischemic events. Safety and efficacy of mechanical thrombectomy in posterior circulation MVO is unclear compared to medical treatment only (1). There is concern that fragility of distal, smaller vessels may have an increased risk of procedural complications (e.g., arterial dissection and or perforations). More people are getting flow divertors over the years and rate of flow diverter of ICA occlusion is 0.05%‐0.08% (2). Here we present a case of embolic fetal PCA stroke with ICA stent occlusion. Methods We report a case of fetal origin posterior cerebral artery occlusion from ICA with literature search of Pubmed. Results 77 years old female with left cavernous‐ICA stent presented from a rehab facility with complaints of word finding difficulty, confusion, right hemiparesis, right sided neglect, and visual disturbance. In the emergency department (ED), her NIHSS was 28. ED presentation was 2.5 hrs after the last known well (LKW). Of note, patient had a with left cavernous‐ICA stent placement a month before the presentation and was noncompliant to antiplatelets. CT head was negative for intracranial bleeding and ASPECT score was 7. CT angiography head and neck was obtained, showing new complete interval occlusion of the intracranial extradural left ICA with reconstitution of distal branches through anterior communicating artery. Patient received IV thrombolytics, intubated for airway protection and was transferred to a comprehensive stroke center for possible mechanical thrombectomy. Time of the arrival was approximately 6 hours after the LKW, reexamination was hindered by the sedation and intubation but was concerning for possible PCA occlusion rather than ICA occlusion. As the localization of ischemic area was unclear, CT perfusion (CTP) was obtained. CTP showed 27 ml penumbra without core infarct in left PCA territory. As fetal origin of left PCA from ICA is occluded, without ability to access through occluded stent, noted risk of left ICA complications with attempts to recanalize stent for noted PCA hypoperfusion outweigh the benefits. With the exam improvement post thrombolytics administration and small penumbra, mechanical thrombectomy was not indicated. Conclusion In acute large vessel occlusion, utility of CT perfusion (CTP) usually recommended after 6 hours from last well known. In this case, patient presented within the 6 hours but the reexamination post thrombolytics was not localizing to suggest large vessel occlusion (LVO) and the territory at risk was unclear. We described a left intracranial ICA flow diversion occlusion without anterior circulation ischemia and left PCA ischemia demonstrated. In this case, CTP was employed to differentiate the territory at risk for triage to appropriate intervention, to differentiate the LVO vs MVO.

MLKL regulates Cx43 ubiquitinational degradation and mediates neuronal necroptosis in ipsilateral thalamus after focal cortical infarction

Necroptosis is known to play an important role in the pathophysiology of cerebral ischemia; however, its role in the occurrence of secondary thalamic injury after focal cerebral infarction and the mechanism about how mixed lineage kinase domain-like (MLKL) executes necroptosis in this pathophysiology are still unclear. In this study, Sprague-Dawley rats were subjected to distal branch of middle cerebral artery occlusion (dMCAO). The expression of MLKL, connexin 43 (Cx43) and Von Hippel-Lindau (VHL) in vitro and in vivo were assessed by Western blot. Bioinformatic methods were used to predict the potential binding sites where MLKL interacted with Cx43, and the ubiquitination degradation of Cx43 regulated by VHL. The interactions among MLKL, Cx43, VHL, and Ubiquitin were assessed by immunoprecipitation. Dye uptake assay were used to examine the Cx43 hemichannels. Intracellular Ca2+ concentration was measured using Fluo-4 AM. Overexpression and site-directed mutagenesis studies were used to study the mechanisms by which MLKL regulates Cx43 ubiquitinational degradation to mediate neuronal necroptosis. We found that MLKL and Cx43 were upregulated in the ventral posterolateral nucleus (VPN) of the ipsilateral thalamus after dMCAO. In the in vitro experiments MLKL and Cx43 were upregulated after TSZ-mediated necroptosis in SH-SY5Y cells. The interaction between MLKL and Cx43 inhibited the K48-linked ubiquitination of Cx43 in necroptotic SH-SY5Y cells. VHL is an E3 ubiquitin ligase for Cx43, and MLKL competes with VHL for binding to Cx43. Interaction of MLKL Ser454 with Cx43 can trigger the opening of Cx43 hemichannels, causing increased intracellular Ca2+, and cell necroptosis. This innovative study at animal models, cellular, and molecular levels is anticipated to clarify the roles of MLKL and Cx43 in thalamic damage after focal cortical infarction. Our findings may help identify novel targets for neurological recovery after cortical infarction.

Incorporation of internal iliac arteries as target vessels during physician-modified fenestrated branched endovascular repair of pararenal abdominal aortic aneurysm with concomitant bilateral short common iliac artery aneurysms

This report describes an alternative endovascular approach to iliac branch devices for treatment of an abdominal aortic aneurysm with concomitant bilateral short common iliac aneurysms. The short distance between the renal arteries and internal iliac artery origins made the addition of distal iliac branch devices to the proximal fenestrated stent graft challenging. We elected to perform physician-modified fenestrated branched endovascular repair, using four fenestrations for the visceral and renal arteries and an additional two directional branches for the bilateral internal iliac arteries. The patient recovered uneventfully, and the 24-month follow-up imaging shows successful aneurysm exclusion with patent internal iliac artery branches.

Effect of Bronchial Blood Flow on Respiratory Heat Exchange: A Mathematical Analysis for Infectious Diseases

Abstract The present study aims to mathematically analyze the role of bronchial blood flow on heat transfer in respiratory infections. In general, the exchange of heat transfer in various infectious diseases like COVID-19 caused by SARS-CoV-2 has adversely affected respiration by reducing the physiological efficiency of the human respiratory tract. The mechanism of heat exchange through airway walls with the bronchial blood circulation still needs to be thoroughly studied for infectious diseases. In this article, a three-dimensional (3D) spatio-temporal theoretical model is developed to estimate the possible role of bronchial blood on heat exchange during breathing. The local description of the model is presented in a comprehensive and consistent dimensionless framework to explicitly state the actual physiological background. The global description is framed by a multicompartment-based approach, and the algorithm is solved using an advanced numerical scheme to ensure computational tractability. The numerical study elucidates the role of inhalation air temperature, breathing cycles, blood perfusion rate, and mucosal hydration. The outcomes of the algorithm estimate the parameters of the isothermal saturation boundary (ISB), which is defined as the position in the respiratory tract where the temperature of inhaled air comes in equilibrium with the body core saturation temperature. The derived results help to understand the pathophysiological threshold limits and recommend the values to evaluate respiratory distress. With the variations of inspiratory flow conditions, it is observed that the ISB position shifts to the distal branches with the increment in inhalation temperature, breathing rate and virus infection, and decrement in blood perfusion rate. The two antiparallel effects are observed: inhalation of cold air transmits the viral infection, and inhalation of warm air produces thermal injury. However, both can be well controlled by suitable ventilation rates. The observed threshold values may be helpful in clinical trials to correlate the anatomic configuration with pathophysiology.

Phylogenetic relationships of the woodlouse flies (Diptera: Rhinophorinae) and the cluster flies (Diptera: Polleniidae).

Phylogenetic relationships within the oestroid subclades Rhinophorinae (Calliphoridae) and Polleniidae were reconstructed for the first time, applying a Sanger sequencing approach using the two protein-coding nuclear markers CAD (carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase; 1794 bp) and MCS (molybdenum cofactor sulfurase; 2078 bp). Three genera of Polleniidae and nineteen genera of Rhinophorinae were analyzed together with a selection of taxa representing the major lineages of Oestroidea (non-rhinophorine Calliphoridae, Oestridae, Sarcophagidae, Tachinidae). The selected markers provide good resolution and moderate to strong support of the distal branches, but weak support for several deeper nodes. Polleniidae (cluster flies) emerge as monophyletic and their sister-group relationship to Tachinidae is confirmed. Morinia Robineau-Desvoidy as currently circumscribed emerges as paraphyletic with regard to Melanodexia Williston, and Pollenia Robineau-Desvoidy is the sister taxon of the Morinia-Melanodexia clade. We propose a classification with two subfamilies, Moriniinae Townsend (including Morinia, Melanodexia, and Alvamaja Rognes), and Polleniinae Brauer & Bergenstamm (including Pollenia, Dexopollenia Townsend, and Xanthotryxus Aldrich). Anthracomyza Malloch and Nesodexia Villeneuve are considered as Oestroidea incertae sedis pending further study. Rhinophorinae (woodlouse flies) emerge as monophyletic and sister to a clade composed of (Ameniinae + (Ameniinae + Phumosiinae)), and a tribal classification is proposed with the subfamily divided into Rhinophorini Robineau-Desvoidy, 1863 and Phytonini Robineau-Desvoidy, 1863 (the Stevenia-group and the Phyto-group of authors, respectively). Oxytachina Brauer & Bergenstamm, 1891, stat. rev. is resurrected to contain nine Afrotropical rhinophorine species currently assigned to genus Rhinomorinia Brauer & Bergenstamm, 1891: Oxytachina approximata (Crosskey, 1977) comb. nov., O. atra (Bischof, 1904) comb. nov., O. bisetosa (Crosskey, 1977) comb. nov., O. capensis (Brauer & Bergenstamm, 1893) comb. nov., O. scutellata (Crosskey, 1977) comb. nov., O. setitibia (Crosskey, 1977) comb. nov., O. verticalis (Crosskey, 1977) comb. nov., O. vittata Brauer & Bergenstamm, 1891, and O. xanthocephala (Bezzi, 1908) comb. nov.

Approach to A Pregnant Woman with Moyamoya Syndrome

Many female patients with the moyamoya disease have normal fertility functions, including those diagnosed before they enter their childbearing years. Moya moya syndrome (MMS) is a rare cerebrovascular disorder caused by segmentary stenosis and occlusions of the small vessels around the circle of Willis and distal branches of carotid arteries. The name of “moyamoya” means “puff of smoke” in Japanese and describes the look of the tangle of tiny vessels formed to compensate for the blockage. This disorder may presented transient paresis, headache, epilepsy, dementia, aphasia, ataxia, and subarachnoid hemorrhage. Although MMS is considered a disease of unknown etiology, infectious and genetic causes have been blamed. However, there has been no comprehensive review of the management of pregnancy and delivery associated with Moyamoya disease. The purpose of this report is to describe a pregnant woman diagnosed with moyamoya disease and to review the literature on other such cases.

An aberrant right subclavian artery in a 63-year-old male cadaver.

An aberrant right subclavian artery (ARSA), also called "arteria lusoria", is described as a right subclavian artery (RSA) with a retro-oesophageal course that most frequently originates as the most distal branch of the aortic arch. The aim of the following study was to present and thoroughly describe a case of an ARSA, its course, branches, and relation to the surrounding anatomical structures and discuss the clinical significance and embryology of this variant. During routine dissection, a 63-year-old male cadaver with an abnormal variant of the RSA was found. The RSA branched off from the aortic arch as the most distal branch. Subsequently, it coursed posteriorly to the trachea and oesophagus at the level of T2 and T3. Abnormalities in the branching pattern of the RSA were also discovered, such as the right vertebral artery originating from the right common carotid artery as its first branch. This study presents a case of an ARSA, which is a rare anatomical variant of the branches of the aortic arch. The course and branching pattern of an aberrant subclavian artery is quite variable, and each variant can be associated with different possible complications. Furthermore, the ARSA is associated with other cardiovascular anomalies, such as the Kommerell's diverticulum. Therefore, knowledge about the possible variations of this anomaly may be of great importance for physicians who encounter this variant in their practice.

The elastography of distal ulnar nerve branches in cyclists

IntroductionForced elbow flexion and pressure during bicycling result in ulnar nerve traction and pressure exerted in Guyon’s canal or the nerve’s distal branches. The compression of the nerves causes a change in their stiffness related to edema and eventually gradual fibrosis. PurposeThis study aimed to evaluate the elastography of terminal branches of the ulnar nerve in cyclists. Study DesignCross-sectional study. MethodsThirty cyclists, 32 healthy individuals, and 32 volunteers with ulnar nerve entrapment neuropathies participated in the study. Each participant underwent a nerve examination of the cubital tunnel, Guyon’s canal and the deep and superficial branches of the ulnar nerve using shear wave elastography. The cyclist group was tested before and after a 2-hour-long workout. ResultsBefore cycling workouts, the ulnar nerve stiffness in the cubital tunnel and Guyon’s canal remained below pathological estimates. Cycling workouts altered nerve stiffness in the cubital tunnel only. Notably, the stiffness of the ulnar terminal branches in cyclists was increased even before training. The mean deep branch stiffness was 50.85 ± 7.60 kPa versus 20.43 ± 5.95 kPa (p < 0.001) in the cyclist and healthy groups, respectively, and the mean superficial branch stiffness was 44 ± 12.45 kPa versus 24.55 ± 8.05 kPa (p < 0.001), respectively. Cycling contributed to a further shift in all observed values. DiscussionThese observations indicate the existence of persistent anatomical changes in the distal ulnar branches in resting cyclists that result in increased stiffness of these nerves. The severity of these changes remains, however, to be determined. ConclusionsThese data show elastography values of the ulnar terminal branches in healthy individuals and cyclists where despite lack of clinical symptoms that they seem to be elevated twice above the healthy range.

Acute Myocardial Infarction Due to Coronary Artery Embolism During Chemotherapy with mFOLFOX-6 Plus Bevacizumab for Metastatic Colon Cancer: A Case Report.

Bevacizumab, a monoclonal antibody against vascular endothelial growth factor, may be associated with arterial embolisms. We herein report a case of acute myocardial infarction caused by coronary embolism during combination chemotherapy with mFOLFOX-6 and bevacizumab in a patient with metastatic colon cancer. Thromboembolism occurred only in the distal right posterolateral branch without stenotic lesions or plaque rupture in the proximal branch of the right coronary artery. Sole thromboaspiration was successfully performed; the final angiogram demonstrated no stenosis in the right coronary artery. Bevacizumab may be associated with acute coronary syndrome in patients with coronary risk factors, despite no significant coronary narrowing.

Biomechanics of abdominal aortic aneurysm in the framework of Windkessel effect and fully-developed inflow velocity via two-way non-linear FSI

Abdominal aortic aneurysm (AAA) is a pathological condition characterised by localised dilation of the infrarenal aorta, which can be fatal if rupture occurs. Current diagnostic criteria for repair are not patient-specific, but computational modelling may help to predict the potential growth and risk of AAA rupture accurately. This paper highlights how important using the Windkessel effect and fully-developed inflow velocity framework for the biomechanical analysis of AAA is; in other words, this research investigates how different boundary conditions in modelling methods affect the ability to correctly represent the biomechanics of AAA with complex non-linear parameters using a two-way fluid–structure interaction (FSI) technique. Time-averaged wall shear stress (TAWSS) is highly sensitive to boundary conditions, so unrealistic or simplified boundary conditions can lead to very different TAWSS results. This study also revealed that the use of outflow 3-element Windkessel boundary conditions on pulsatile pressure affects the flow pattern and increases the flow recirculation period. By accounting for the Windkessel effect and preventing backflow in numerical studies of AAA, the maximum displacement found in the distal branches can also be reduced. Models assuming plug velocity profiles overestimate peak wall stress by approximately 20% compared with models using fully developed parabolic inlet velocity profiles. This study incorporated a three-layer anisotropic material model and non-Newtonian fluid properties into the simulation, providing a more realistic representation of the effect of boundary condition selection on AAA mechanics. The results summarised from the parametric study could contribute to better prediction of AAA growth and rupture risk, and have important implications for the development of improved treatment strategies for AAA patients.

Computational modelling of airflow in distal airways using hybrid lung model

ABSTRACT A major challenge in computational fluid dynamics (CFD) modelling of the human respiratory system is allowing for the variation of geometric scale. A methodology is proposed that enables CFD analysis from the middle through the distal airways to the alveolar level. The methodology relies on a hybrid lung geometry integrating a primary tracheobronchial tree (TBT) up to the fifth generation (section 1) and distal airway (section 2). Section 1 comprises of the middle airways reconstructed from patient CT scans. Section 2 comprises of the distal airway branching tree generated based on deterministic algorithm. The hybrid model allows the application of physiologically relevant boundary conditions in lieu of simplistic approximations used in previous studies. Two different breathing conditions are considered adapted from previous studies, representing resting and exercise activity. The predicted flow variables are assessed for numerical accuracy and validated by comparison with published experimental and numerical data.

Replacement of the distal radio-ulnar joint with asemi-constrained Scheker DRUJ prosthesis.

To describe the indications, operative technique, and long-term outcomes of patients treated with the Scheker (Aptis) distal radio-ulnar joint (DRUJ) prosthesis. The Scheker prosthesis is intended to replace the DRUJ in patients with rheumatoid, degenerative, or posttraumatic arthritis of the sigmoid notch and/or ulnar head, or in cases of gross instability of the DRUJ. Moreover, aScheker prosthesis can be used to treat failed salvage procedures, such as the Sauvé-Kapandji procedure, ulnar head resection, and ulnar head arthroplasty. Severe osteoporosis, active infection, immature skeleton, less than 14cm of the proximal ulna remaining. In supine position with the forearm in full pronation, an ulnar S‑shaped incision is made. The ulnar head is resected and the proximal part is brought to the palmar side to enable visualization of the sigmoid notch. Following preparation of the sigmoid notch and the proximal ulnar part of the radius, aradial plate is attached. When the position is verified with fluoroscopy, screw holes are drilled together with aseparate hole for the radial peg. Ametal stem is inserted in the ulnar shaft. Apolymer ball is then slid on to apolished peg on top of the ulnar stem. This polymer ball is seated in the socket of the radial plate and fixed with asmall metal cap. Radiographic images are made for confirmation of correct positioning and full pro- and supination is tested, after which the wound is closed. After 48 h of pressure bandages, patients are instructed to start with full range of motion and weight-bearing exercises under the guidance of ahand therapist. Weight-bearing is constrained to 10kg. We retrospectively assessed 50Scheker prostheses in 48patients treated between 2016 and 2021. The median age was 56years (IQR: 50-65) and 30 (60%) were female. Median follow-up was 29months (IQR: 12-48). The primary outcome was the PRWE score. The median PRWE score at the final follow-up was 23 (IQR: 4-52) for the operated side versus amedian PRWE score of 5 (IQR: 0-25) for the non-operated side (p < 0.005). Six patients had acomplication. Three patients developed extensor carpi ulnaris tendinitis with one patient requiring additional surgery. One patient developed aneuroma of the distal branch of the ulnar nerve that was surgically removed. One synovectomy was performed because of synovitis and one endoscopic ulnar release was performed because of hyperesthesia of the ulnar area. None of the prostheses had to be removed.

Subcutaneous Dorsomedial Triangle of Forearm: Surgical Anatomy and Clinical Implication.

Background The purpose of the study was to provide a practical landmark for localizing the dorsal branch of the ulnar artery and nerve, to approach for microsurgical flaps, for harvesting nerve grafts and also to avoid these nerves during insertion of wrist arthroscopy portals. Material and methods Forty adult cadaveric upper limbs (20 right and 20 left) were dissected for localizing the dorsal branches of the ulnar artery and nerve. The ramification patterns of the nerve were mapped. The wrist arthroscopy portals are located radial and ulnar to the tendon of extensor carpi ulnaris at the level of the wrist joint, and their designated names are '6R & 6U', respectively. The distance of branches of the nerve from the 6U and 6R portals for wrist arthroscopy was recorded. Results The present study has delineated asubcutaneous dorsomedial triangular area in the distal forearm. The construction of this triangle uses palpable landmarks, i.e. pisiform bone, styloid process and subcutaneous border of the ulna. The measure of the sides of the triangle uses proportion rather than absolute measurements and hence is person specific. The dorsal branches of the ulnar nerve and artery are consistently given off in the triangle's upper third and middle third, respectively. Four branching patterns have been mapped, with one dominant pattern in 67.5% of limbs. In three-fourths of cases, one branch of the dorsal branch of the ulnar nerve consistently overlies the 6U portal and hence runs a higher risk of injury. Conclusion The study suggests more practical, accurate, reliable and consistent surface landmarks for the localization of the dorsal branch of the ulnar artery and nerve for reconstructive microsurgery for distal hand defects.