Learning Curve Effect of Combined Technique Thrombectomy as First-Line Attempt for Acute Ischemic Stroke: A Single-Center Retrospective Study

OBJECTIVES

We retrospectively examined the initial experience and learning curve after the introduction of thrombectomy with the combined technique using an aspiration catheter and a stent retriever as first-line attempt for acute ischemic stroke.

METHODS

Consecutive patients undergoing thrombectomy for acute ischemic stroke at our institution between January 2020 and December 2022 were divided into 3 groups according to the year of thrombectomy. Patient characteristics and procedural, safety, and clinical outcomes were compared between the three year periods to determine predictors of favorable clinical outcome.

RESULTS

In 2020, 2021, and 2022, the numbers of patients were 74, 70, and 90, respectively, with similar patient characteristics across the three years; successful recanalization rates were 79.7%, 97.1%, and 93.3%, respectively (P < 0.01 for the first 2 years); median procedure times were 67, 43, and 32 minutes, respectively (P < 0.01 for the first 2 years and P = 0.018 for the last 2 years); first pass effect rates were 20.3%, 41.4%, and 44.4%, respectively (P < 0.01 for the first 2 years); symptomatic intracranial hemorrhage rates were 14.9%, 2.9%, and 1.1%, respectively (P = 0.018 for the first 2 years); and percentages of modified Rankin Scale score 0-2 at 90 days were 24.3%, 42.9%, and 41.1%, respectively (P = 0.022 for the first 2 years). Procedure time (P = 0.038) and successful recanalization (P = 0.041) were independent predictors of favorable clinical outcome.

CONCLUSIONS

The learning curve effect of the combined technique may be associated with better clinical outcome due to increased successful recanalization rates, shortened procedure time, and reduced symptomatic intracranial hemorrhage.

Optimal endovascular therapy technique for isolated intracranial atherothrombotic stroke-related large vessel occlusion in the acute to subacute stage

BACKGROUND AND PURPOSE

Reocclusion after treatment is a concern in endovascular therapy (EVT) for isolated intracranial atherothrombotic stroke-related large vessel occlusion (AT-LVO). However, the optimal EVT technique for AT-LVO has not yet been investigated. This study evaluated the optimal EVT technique for AT-LVO in a real-world setting.

MATERIALS AND METHODS

We conducted a historical multicenter registry study at 51 centers that enrolled patients with AT-LVO. We divided the patients into three groups based on the EVT technique: mechanical thrombectomy alone (MT-only), percutaneous transluminal angioplasty (PTA), and stent deployment (Stent). MT alone was classified into the MT-only group, PTA and MT-PTA into the PTA group, and MT-Stent, MT-PTA-Stent, PTA-Stent, and Stent-only into the Stent group. The primary outcome was the incidence of reocclusion of the treated vessels within 90 days of EVT completion.

RESULTS

We enrolled 770 patients and analyzed 509 patients. The rates in the MT-only, PTA, and Stent groups were 40.7, 44.4, and 14.9%, respectively. The incidence rate of residual stenosis >70% of final angiography was significantly higher in the MT-only group than in the PTA and Stent groups (MT-only vs. PTA vs. Stent: 34.5% vs. 26.3% vs. 13.2%, p=0.002). The reocclusion rate was significantly lower in the PTA group than in the MT-only group (adjusted hazard ratio [95% confidence interval], 0.48 [0.29-0.80]). Of the patients, 83.5% experienced reocclusion within 10 days after EVT. Alarmingly, a substantial subset (approximately 62.0%) of patients underwent reocclusion within 2 days of EVT. The incidence of modified Rankin scale scores of 0-2 90 days after EVT was not significantly different among the three groups. The incidences of symptomatic intracranial hemorrhage (ICH), any other ICH, and death were not significantly different.

CONCLUSIONS

The incidence rate of reocclusion was significantly lower in the PTA group than in the MT-only group. We found no significant difference in reocclusion rates between the Stent and MT-only groups. In Japan, GP IIb/IIIa inhibitors are not reimbursed. Therefore, PTA might be the preferred choice for AT-LVOs due to the higher reocclusion risk with MT-only. Reocclusion was likely to occur within 10 days, particularly within 2 days post-EVT.

ABBREVIATIONS

EVT = endovascular treatment; LVO = large vessel occlusion; MT = mechanical thrombectomy; PTA = percutaneous transluminal angioplasty; ICH = intracranial hemorrhage; SD = standard deviation; IQR = interquartile range; HRs = hazard ratios; BMI = body mass index; LDL = low-density lipoprotein; HDL = high-density lipoprotein; DAPT = dual antiplatelet therapy; TAPT = triple antiplatelet therapy.

Immunoglobulin G4-related disease manifesting as peripheral neuropathy: A rare clinical symptom due to rare autoimmune disease

Background

Nervous system involvement in immunoglobulin G4-related disease (IgG4-RD) has been rarely reported.

Case Description

We describe an unusual case of IgG4-RD manifested as paresthesia in the right lower extremity. A 51-year-old male presented with paresthesia in the right S1-S3 regions. A neurological examination revealed peripheral neuropathy. Blood examination results were normal, barring slightly elevated IgG levels. Initial magnetic resonance imaging of the swollen right S1 and S2 nerve roots revealed lymphoma, schwannoma, and sarcoidosis. However, following the biopsy, the pathological findings were not typical of these diseases. Abdominal computed tomography revealed perirenal lesions, and IgG4-RD was suspected. The patient had a serum IgG4 level of 724 mg/dL. Additional pathological evaluations of the swollen S1 nerve revealed findings that corresponded to the diagnostic criteria for IgG4-RD. Oral steroid therapy was initiated, which improved paresthesia, and the swollen S1 nerve root gradually shrank.

Conclusion

This report highlights a rare case of IgG4-RD involving nerve roots that neurosurgeons should consider.

Factors related to vessel displacement due to stent retriever retraction: An in vitro study

BACKGROUND

Thrombectomy with a stent retriever (SR) may lead to intracranial hemorrhage due to vessel displacement. We aimed to explore factors related to vessel displacement using an in vitro vessel model.

METHODS

A vessel model mimicking two-dimensional left internal carotid angiography findings was used in this study. Six SR types (Solitaire 3 × 40, 4 × 40, and 6 × 40; Embotrap 5 × 37; Trevo 4 × 41; and Tron 4 × 40) were fully deployed in the M2 ascending, M2 bend, or M1 horizontal portion. Subsequently, the SR was retracted, and the vessel displacement, maximum SR retraction force, and angle of the M2 bend portion were measured. A total of 180 SR retraction experiments were conducted using 6 SR types at 3 deployment positions with 10 repetitions each.

RESULTS

The mean maximum distance of vessel displacement for Embotrap Ⅲ 5 × 37 (6.4 ± 3.5 mm, n = 30) was significantly longer than that for the other five SR types (p = 0.029 for Solitaire 6 × 40 and p < 0.001 for the others, respectively). Vessel displacement was significantly longer in the M2 ascending portion group (5.4 ± 3.0 mm, n = 60) than in the M2 bend portion group (3.3 ± 1.6 mm, n = 60) (p < 0.001) and it was significantly longer in the M2 bend portion group than in the M1 horizontal portion group (1.1 ± 0.7 mm, n = 60) (p < 0.001). A positive correlation existed between the mean maximum SR retraction force or mean angle of the M2 bend portion due to SR retraction (i.e., vessel straightening) and the mean maximum distance of vessel displacement (r = 0.90, p < 0.001; r = 0.90, p < 0.001, respectively).

CONCLUSIONS

Vessel displacement varied with the SR type, size, and deployment position. Moreover, vessel displacement correlated with the SR retraction force or vessel straightening of the M2 bend portion.

Aortogenic calcified cerebral embolism diagnosed with an embolus retrieved by thrombectomy: illustrative case

BACKGROUND

Calcified cerebral embolism has been reported as a cause of acute cerebral infarction, but an aortogenic origin has rarely been identified as the embolic source. The authors describe a case of aortogenic calcified cerebral embolism in a patient with other embolic sources.

OBSERVATIONS

In a patient with cerebral infarction and atrial fibrillation, a white hard embolus was retrieved by mechanical thrombectomy. Pathological analysis of the embolus revealed that it was mostly calcified, with some foam cells and giant cells. The macroscopic and pathological findings allowed the authors to finally diagnose an aortogenic calcified cerebral embolism.

LESSONS

Even in patients with cardiogenic embolic sources, it is possible to identify a complex aortic atheroma with calcification as the embolic source, based on the macroscopic and pathological findings of the embolus retrieved by mechanical thrombectomy.

Assessment of maxillary sinus fluid volume for postmortem diagnosis of drowning

INTRODUCTION

Drowning is a comprehensive and exclusive diagnosis at autopsy. Autopsy findings such as pleural effusion and waterlogged lungs contribute to the diagnosis. Herein, we aim to reveal the practical usefulness and postmortem changes of the maxillary sinus fluid volume to diagnose drowning.

METHODS

We evaluated 52 drowning and 59 nondrowning cases. The maxillary sinus fluid volume was measured using a computed tomography (CT) scan, and pleural effusion volume and lung weight were manually measured at autopsy. The utility of these three indices for diagnosing drowning and its postmortem changes was evaluated.

RESULTS

The maxillary sinus fluid volume was significantly higher in drowning cases than in other external causes and cardiovascular death cases. Receiver operating characteristic curve analysis revealed that a total maxillary sinus fluid volume >1.04 mL more usefully indicated drowning (odds ratio, 8.19) than a total pleural effusion volume >175 mL (odds ratio, 7.23) and a total lung weight >829 g (odds ratio, 2.29). The combination of maxillary sinus fluid volume and pleural effusion volume more effectively predicted drowning than one index alone. Moreover, the maxillary sinus fluid volume was less influenced by the postmortem interval than the other two indices up to a week after death.

CONCLUSION

Maxillary sinus fluid volume can be more useful than pleural effusion volume and lung weight with higher sensitivity and odds ratio for diagnosing drowning.

IMPLICATIONS FOR PRACTICE

Fluid accumulation in both the maxillary sinuses strongly predicts drowning in the postmortem imaging.

A case of immunoglobulin G4-related retroperitoneal fibrosis and hypophysitis with antecedent respiratory disease followed by spontaneous remission and recurrence

A 65-year-old man presented with apparent bronchopneumonia. After treatment with antibiotics, he showed eosinophilia. Computed tomography (CT) imaging revealed bilateral consolidation, ground-glass opacities with nodular consolidations, and pleural effusion. Lung biopsy showed organising pneumonia with lymphoplasmacytic infiltration in the alveolar septa and in the thickened pleura and interlobular septa. All pulmonary abnormalities spontaneously went into remission within 12 months. At 73 years old, a follow-up CT scan revealed small nodules in both lungs and the review of the head CT scan showed thickening of the pituitary stalk in studying prolonged headache. Two years later, he visited the hospital complaining of severe oedema on the lower extremities with high serum immunoglobulin (Ig)G4 186 mg/dl. A whole-body CT scan showed retroperitoneal mass surrounding aortic bifurcation and compressing inferior vena cava, pituitary stalk thickening and gland swelling, and enlarged pulmonary nodules. Anterior pituitary stimulation tests showed central hypothyroidism, central hypogonadism, and adult growth hormone deficiency with partial primary hypoadrenocorticism. Retroperitoneal mass biopsy showed storiform fibrosis and obliterative phlebitis with marked lymphoplasmacytic infiltration with moderate IgG4-positivity. Immunostaining of the former lung specimen revealed dense interstitial infiltration of IgG4-positive cells. These findings indicated metachronous development of IgG4-related disease in lung, hypophysis, and retroperitoneum, according to the recent comprehensive diagnostic criteria of IgG4-related disease. Glucocorticoid therapy ameliorated oedema, on the other hand, unmasked partial diabetes insipidus at the initial dose of the treatment. Hypothyroidism and retroperitoneal mass regressed at 6 months of the treatment. This case warns us that long-term follow-up from prodromal to remission is necessary for the treatment of IgG4-related disease.

Factors for failure of ultrasound-guided compression repair for femoral pseudoaneurysms after neuroendovascular therapy

OBJECTIVE

Pseudoaneurysms are a serious complication of neuroendovascular therapy with femoral artery puncture, for which ultrasound-guided compression repair (UGCR) is often the first choice of radical therapy. We sought to retrospectively investigate the factors for failure of UGCR for pseudoaneurysm at the femoral artery puncture site.

METHODS

Among patients undergoing neuroendovascular therapy with femoral artery puncture at our hospital between January 2018 and April 2021, those who received a diagnosis of pseudoaneurysm and underwent UGCR were enrolled. They were classified into two groups according to whether UGCR was successful (UGCR group) or was converted to surgical repair (SR group). Patient and procedural characteristics were compared between the two groups.

RESULTS

During the study period, 577 patients underwent neuroendovascular therapy with femoral artery puncture, 10 of whom (1.7%) received a diagnosis of pseudoaneurysm and underwent UGCR. There were seven patients in the UGCR group and three patients in the SR group. The sheath diameter tended to be larger in the SR group than in the UGCR group (p = 0.16). The modified Rankin scale score when a diagnosis of pseudoaneurysm was made was significantly lower in the SR group than in the UGCR group (1 [0-2] vs. 3 [2-5], p = 0.037).

CONCLUSIONS

Physical activity may be associated with failure of UGCR. In patients with high physical activity, the use of sedatives and analgesics to keep them at rest during puncture site compression after UGCR may lead to successful UGCR.

Impact of methotrexate on humoral and cellular immune responses to SARS-CoV-2 mRNA vaccine in patients with rheumatoid arthritis

The aim of this study was to longitudinally evaluate the undetermined impact of methotrexate (MTX) on the cumulative immunogenicity elicited by three doses of SARS-CoV-2 mRNA vaccination in patients with rheumatoid arthritis (RA). We prospectively evaluated vaccine-induced immune responses following the first dose, 1 and 6 months after the second dose, and 1 month after the third dose of BNT162b2 or mRNA-1273 in 144 SARS-CoV-2 naïve participants (70 patients with RA, 29 disease controls without immunosuppressive conditions, and 45 healthy controls). Humoral immune responses were assessed by quantifying anti-spike IgG antibody titers and the capacity of circulating antibodies to neutralize the ancestral SARS-CoV-2 strain and the Alpha, Delta, and Omicron variants. Vaccine-induced T-cell responses were measured using an interferon-gamma release assay. At 1 and 6 months after the second dose, anti-spike titers were highest in healthy controls, followed by disease controls and patients with RA. Multivariate analyses revealed that MTX treatment was significantly associated with a decrease in anti-spike titers, neutralizing activity, and SARS-CoV-2-specific interferon-gamma levels. Furthermore, MTX dose per body weight was negatively correlated with these two indices of humoral immune response. The third vaccine dose boosted anti-spike titers, especially in patients receiving MTX, while sera from these patients neutralized the Omicron variant far less robustly than those from healthy controls. In conclusion, MTX attenuated immunogenicity following two doses of SARS-CoV-2 mRNA vaccine in patients with RA, particularly resulting in dose-dependent suppression of the humoral immune response. Furthermore, MTX deteriorated the neutralizing activity against the Omicron variant, even after the third immunization.

Solvent-assisted synthesis of Ag2Se and Ag2S nanoparticles on carbon fabric for enhanced thermoelectric performance

The challenge of developing low-cost, highly flexible, and high-performance thermoelectric (TE) materials persists due to the low thermoelectric efficiency of conducting polymers and the inflexibility of inorganic materials. In this study, we successfully integrated Ag2Se and Ag2S with highly conductive carbon fabric (CF) to produce a flexible thermoelectric material. A facile one-step solvothermal method was employed to synthesize the Ag2Se-CF and Ag2S-CF, which were then subjected to X-ray analysis to confine the phase formation of Ag2Se and Ag2S on the carbon fabric. The analysis revealed that Ag2Se and Ag2S nanoparticles were tightly packed on the surface of carbon fabric, and compositional analysis confirmed the interaction between the material and carbon fabric. The thermoelectric properties of Ag2Se-CF and Ag2S-CF were significantly altered due to carrier concentration and mobility variations, resulting in a low power factor of 6.7 μW/mK2 for Ag2Se-CF and a high-power factor of 24 μW/mK2 at 373 K for Ag2S-CF. The growth of Ag2Se-CF and Ag2S-CF on carbon fabric led to an enhancement in their thermoelectric properties. Further, TE legs were fabricated using the Ag2Se-CF (p-type) and Ag2S-CF (n-type), and the fabricated legs exhibited an output voltage of ∼20 mV to ∼86.65 mV at a temperature gradient (ΔT) of 3-8 K. This work represents a cutting-edge approach to the fabrication of high-performance, wearable thermoelectric devices.

Anterior condylar arteriovenous fistula mainly fed by peripheral branches of the bilateral internal maxillary arteries: illustrative case

BACKGROUND

The main feeding artery of an anterior condylar arteriovenous fistula (AC-AVF) is the ascending pharyngeal artery and rarely the internal maxillary artery.

OBSERVATIONS

A 58-year-old male with a history of sinusitis since adolescence presented with a 5-year history of bilateral pulsatile tinnitus and a 2-month history of right ocular symptoms. Angiography showed that the peripheral branches of the bilateral internal maxillary arteries were the main feeding arteries of the AC-AVF and that they gathered in the clivus with a relatively large shunted pouch in the left jugular tubercle. Shunt flow drained to the right external jugular vein via the right superior ophthalmic vein. A sheath was placed in the right external jugular vein, and a small distal access catheter was guided to the right superior ophthalmic vein to allow the microcatheter to reach the shunted pouch. Selective angiography of the contralateral sphenopalatine artery allowed us to confirm the gathering site of the feeding arteries and the shunted pouch and archive the complete occlusion.

LESSONS

Selective angiography of the contralateral sphenopalatine artery may be useful to confirm the gathering site of the peripheral branches of the bilateral internal maxillary arteries in an AC-AVF.

White Embolus-induced Basilar Artery Occlusion Due to Pulmonary Vein Invasion of a Metastasis of a Malignant Melanoma

An 80-year-old woman presented with impaired consciousness after malignant melanoma resection. Magnetic resonance angiography showed basilar artery occlusion, which was subjected to mechanical thrombectomy for recanalization. A pathological analysis of the retrieved embolus revealed that it was derived from a metastasis of malignant melanoma. Contrast-enhanced chest computed tomography showed multiple pulmonary metastases, one of which was in the right upper lobe and invaded the pulmonary vein. To our knowledge, this is the first case of white embolus-induced cerebral embolism due to pulmonary vein invasion of a metastasis of a pathologically diagnosed malignant melanoma.

Artificial placenta technology: History, potential and perception

As presently conceptualised, the artificial placenta (AP) is an experimental life support platform for extremely preterm infants (i.e. 400-600 g; 21-23+6 weeks of gestation) born at the border of viability. It is based around the oxygenation of the periviable fetus using gas-exchangers connected to the fetal vasculature. In this system, the lung remains fluid-filled and the fetus remains in a quiescent state. The AP has been in development for some sixty years. Over this time, animal experimental models have evolved iteratively from employing external pump-driven systems used to support comparatively mature fetuses (generally goats or sheep) to platforms driven by the fetal heart and used successfully to maintain extremely premature fetuses weighing around 600 g. Simultaneously, sizable advances in neonatal and obstetric care mean that the nature of a potential candidate patient for this therapy, and thus the threshold success level for justifying its adoption, have both changed markedly since this approach was first conceived. Five landmark breakthroughs have occurred over the developmental history of the AP: i) the first human studies reported in the 1950's; ii) foundation animal studies reported in the 1960's; iii) the first extended use of AP technology combined with fetal pulmonary resuscitation reported in the 1990s; iv) the development of AP systems powered by the fetal heart reported in the 2000's; and v) the adaption of this technology to maintain extremely preterm fetuses (i.e. 500-600 g body weight) reported in the 2010's. Using this framework, the present paper will provide a review of the developmental history of this long-running experimental system and up-to-date assessment of the published field today. With the apparent acceleration of AP technology towards clinical application, there has been an increase in the attention paid to the field, along with some inaccurate commentary regarding its potential application and merits. Additionally, this paper will address several misrepresentations regarding the potential application of AP technology that serve to distract from the significant potential of this approach to greatly improve outcomes for extremely preterm infants born at or close to the present border of viability.

Endovascular therapy for acute intracranial large vessel occlusion due to atherothrombosis: Multicenter historical registry

BACKGROUND

Atherothrombotic stroke-related large vessel occlusion (AT-LVO) is caused by two etiologies, the intracranial artery occlusion due to in situ occlusion (intracranial group) or due to embolism from cervical carotid occlusion or stenosis (tandem group). The prognosis and reocclusion rate of each etiology after endovascular therapy (EVT) is unclear.

METHODS

We conducted a historical multicenter registry study at 51 Japanese centers to compare the prognoses of AT-LVO between two etiologies. The primary outcome was the incidence of recurrent ischemic stroke or reocclusion of the treated vessels within 90 days after EVT. Each of the primary outcome means the incidence of recurrent ischemic stroke and reocclusion of the treated vessels within 90 days after EVT.

RESULTS

We analyzed 582 patients (338 in the intracranial group and 244 in the tandem group). Patients in the intracranial group were younger (mean 71.9 vs 74.5, p=0.003), more of them were female and fewer of them were current smokers than those in the tandem group. In the tandem group, the patients' National Institutes of Health Stroke Scale score on admission was higher (13 vs 15, p=0.006), onset to puncture time was shorter (299 [145-631] vs 232 [144-459] minutes, p=0.03) and Alberta Stroke Program Early CT Score (ASPECTS) was lower (8 [7-9] vs 8 [6-9], p=0.0002). The primary outcome was higher in the intracranial group (22.5% vs 8.2%, p<0.0001). However, any ICH and death were not significantly different in the two groups.

CONCLUSIONS

The incidence of recurrent ischemic stroke or reocclusion after EVT for AT-LVO was higher in the intracranial group.

Parent artery occlusion for cerebral infarction after spontaneous recanalization in traumatic vertebral artery: A case report

Background

There is no established treatment strategy for traumatic vertebral artery occlusion that does not require cervical spine repair surgery.

Case Description

A 49-year-old man was brought to our hospital with traffic trauma. Fractures were observed in the left lateral mass and transverse process of Atlas and the left vertebral artery was occluded at the level of the foramen transversum of Atlas. No acute cerebral infarction was observed. Because the cervical spinal cord was not compressed by the fracture, no repair surgery was performed. Continuous intravenous heparin and oral aspirin were started for traumatic vertebral artery occlusion. Thereafter, the left vertebral artery spontaneously recanalized, but no cerebral infarction was observed. The patient was discharged home on day 16 of injury. Four days later, however, he was brought to our hospital with nausea and lightheadedness. Acute cerebral infarction was observed in the left posterior inferior cerebellar artery territory and a thrombus in the left vertebral artery V4 segment. Parent artery occlusion was performed to prevent further cerebral infarction due to distal embolization of the thrombus. No further cerebral infarction occurred after the operation and the patient was discharged home with a modified Rankin scale score of 1.

Conclusion

In cases of traumatic vertebral artery occlusion without an occlusive mechanism, parent artery occlusion may be considered in terms of recanalization risk, regardless of the need for repair surgery.

Factors related to white thrombi in acute ischemic stroke in cancer patients

OBJECTIVES

Thrombi in cerebral large vessel occlusion associated with active cancer are often fibrin and platelet-rich white thrombi. However, evaluating the thrombus composition in a short time before thrombectomy is often ineffective. We sought to determine factors related to white thrombi in acute ischemic stroke due to large vessel occlusion in cancer patients.

METHODS

Consecutive cancer patients undergoing thrombectomy for acute ischemic stroke due to large vessel occlusion between January 2018 and May 2022 were retrospectively reviewed. The patients were classified into white thrombus and red thrombus groups on the basis of the pathological findings of retrieved thrombi. Patient characteristics and laboratory findings were compared between the two groups.

RESULTS

There were 12 patients in the white thrombus group and 11 patients in the red thrombus group. Active cancer was significantly more in the white thrombus group than in the red thrombus group (91.7% vs. 36.3%, p = 0.0094). Internal carotid artery occlusion was significantly less in the white thrombus group than in the red thrombus group (0% vs. 36.4%, p = 0.037). Among laboratory findings, D-dimer levels were an independent factor associated with white thrombi (odds ratio 8.97 [95% confidence interval 1.71-368.99], p < 0.0001). The cutoff value of D-dimer levels for predicting white thrombi was 3.5 μg/mL (83.3% sensitivity and 100% specificity).

CONCLUSIONS

In acute ischemic stroke in cancer patients, active cancer, no internal carotid artery occlusion, and higher D-dimer levels (≥3.5 μg/mL) may be associated with occlusion with fibrin and platelet-rich white thrombi.

Atrial fibrillation activation patterns predict freedom from arrhythmias after catheter ablation: utility of ExTRa mapping™

Background

Mechanisms underlying atrial fibrillation (AF) are widely complex and vary tremendously among individuals.

Objectives

This retrospective study aimed to investigate the association between AF activation patterns and clinical outcomes post-ablation.

Methods

Fifty-five AF patients (64.0 ± 12.9 years; 41 men; 17 paroxysmal) underwent bi-atrial endocardial driver mapping during AF pre-ablation with a real-time phase mapping system (ExTRa Mapping). The nonpassively activated ratio (%NP) of meandering rotors and multiple wavelets relative to the recording time was evaluated in 26 atrial segments [15 in the left atrium (LA) and 11 in the right atrium]. Irrespective of the mapping results, all patients underwent standard AF ablation via cryoballoons and/or radiofrequency catheters.

Results

In a median follow-up interval of 27(14-30) months, 69.1% of patients were free from recurrent arrhythmias and antiarrhythmic drugs at one year post-procedure. Patients with recurrent AF were more likely to have non-paroxysmal AF, a significantly larger LA size, and higher LA maximal %NP(LAmax%NP) and LA anterior wall %NP(LAAW%NP) than those without recurrent AF. A multivariate Cox regression analysis showed that both an LAmax%NP (hazard ratio [HR] = 1.075; 95% confidence interval [CI] = 1.02-1.14, p = 0.012) and LAAW%NP (HR = 1.061; 95% CI = 1.01-1.11, p = 0.013) were independent predictors of atrial arrhythmia recurrence. The optimal cutoff points for the LAmax%NP and LAAW%NP for predicting AF recurrence were 64.5% and 60.0%, respectively. A Kaplan-Meier analysis demonstrated that both an LAmax%NP > 64.5% (p = 0.0062) and LAAW%NP > 60.0% (p = 0.014) were associated with more frequent AF recurrences.

Conclusion

Baseline AF activation pattern mapping may aid in predicting freedom from arrhythmias after standard AF ablation procedures.

Disconnection of a stent retriever's pushwire caught by an accordion-like deformed aspiration catheter during mechanical thrombectomy: illustrative case

BACKGROUND

In mechanical thrombectomy for acute large vessel occlusion, a combined technique of using both a stent retriever and an aspiration catheter has been widely used. The authors report a case in which a stent retriever's pushwire and a microcatheter were caught and disconnected by an accordion-like deformed aspiration catheter.

OBSERVATIONS

A 74-year-old man underwent mechanical thrombectomy for a left M1 occlusion. A stent retriever was deployed from the left M2 to the left distal M1, and an aspiration catheter was advanced to the left distal M1. When the stent retriever and microcatheter were pulled into the aspiration catheter at the distal M1 without releasing the deflection, traction resistance of the stent retriever occurred, and the aspiration catheter contracted and deformed like an accordion distal to the tip of the guiding catheter. The stent retriever's pushwire and the microcatheter were caught and disconnected.

LESSONS

When a stent retriever is pulled into a flexible aspiration catheter in a case with vascular tortuosity, it may be caught by an accordion-like deformed aspiration catheter and disconnected. It is necessary to release the deflection of the aspiration catheter once traction resistance of the stent retriever and deflection of the aspiration catheter occur.

Cavernous sinus dural arteriovenous fistula embolized through an occluded superior petrosal sinus: illustrative case

BACKGROUND

Transvenous embolization for cavernous sinus (CS) dural arteriovenous fistulas (CS-DAVFs) with limitations of the major access routes to the CS is challenging.

OBSERVATIONS

A 74-year-old woman presented with left-sided conjunctival injection and exophthalmos. Cerebral angiography showed a left CS-DAVF draining into the left uncal vein and superior ophthalmic vein, with the fistulous point located in the posterosuperior compartment of the left CS. The left inferior petrosal sinus and internal jugular vein were occluded, and no drainage route from the left superior ophthalmic vein was seen. The anterior segment of the left superior petrosal sinus (SPS) was occluded, but the posterior segment was not. Microangiography from the posterior segment of the left SPS showed a beak-like orifice in the anterior segment of the left SPS toward the left CS. A micro-guidewire was guided through the beak-like orifice, and the microcatheter was advanced into the left CS. The left CS was packed and the DAVF was occluded.

LESSONS

Transvenous embolization through an occluded SPS may be an option in the endovascular treatment of CS-DAVFs. Penetration along the beak-like orifice of the occluded SPS visualized by venography at the blind end of the SPS may be useful in reaching the CS via the SPS.

De novo expansion formation in the outer curvature of the internal carotid artery after flow diverter deployment for an infectious cavernous carotid aneurysm: illustrative case

BACKGROUND

Infectious aneurysms very rarely occur in the cavernous carotid artery. Recently, treatment by flow diverter implantation with preservation of the parent artery has been the treatment of choice.

OBSERVATIONS

A 64-year-old woman presented with stenosis at the C5 segment of the left internal carotid artery (ICA), followed by ocular symptoms within 2 weeks, with a de novo aneurysm in the left cavernous carotid artery and wall irregularity with stenosis from the C2 to C5 segments of the left ICA. Antimicrobial therapy was given for 6 weeks, and a Pipeline Flex Shield was implanted. Angiography 6 months after treatment showed complete obliteration of the infectious aneurysm and improvement of the stenosis. However, de novo expansions were formed in the outer curvature of C3 and C4 segments of the ICA where the Pipeline device had been deployed.

LESSONS

Aneurysms that develop rapidly and show shape changes over time, accompanied by fever and inflammation, may be associated with an infection. Because of the fragility in the irregular wall of the parent vessel associated with infectious aneurysms, de novo expansion may form in the outer curvature of the parent vessel after flow diverter placement; thus, careful follow-up is necessary.

Intraoperative identification of the lateral spinal artery in a case of craniocervical junction dural arteriovenous fistula surgically obliterated

BACKGROUND

The formation of a dural arteriovenous fistula (DAVF) at the craniocervical junction is rare. Such a fistula can be fed by the branches of the vertebral and external carotid arteries. The lateral spinal artery can branch from the vertebral artery. The feeders of a DAVF at the craniocervical junction are often diagnosed on preoperative angiography, and there is little reported evidence on the intraoperative diagnosis of the lateral spinal artery.

CASE DESCRIPTION

An 84-year-old man presented with motor weakness and sensory disturbance of the lower extremities. Edematous changes in the medulla oblongata and cervical spinal cord were observed on magnetic resonance imaging. Cerebral angiography revealed a DAVF fed by a branch of the vertebral artery, with a shunting point located in the dura of the right condyle; the main drain was the anterior spinal vein. The DAVF drain was surgically obliterated to prevent hemorrhagic events and improve neurological symptoms. Intraoperatively, an artery branching from the feeder of the DAVF was identified and preserved. The patient had a good postoperative course, and the neurological symptoms were ameliorated. Follow-up cerebral angiography revealed proximal branching of the lateral spinal artery from the feeding artery of the DAVF.

CONCLUSION

A lateral spinal artery was identified intraoperatively while a DAVF at the craniocervical junction was obliterated. This suggests that preoperative imaging should be carefully reviewed, and endovascular procedures should consider such possibilities to avoid adverse ischemic outcomes.

Enhancement of thermoelectric power factor via electron energy filtering in Cu doped MoS2 on carbon fabric for wearable thermoelectric generator applications

The design and construction of state-of-the-art wearable thermoelectric materials are important for the development of self-powered wearable thermoelectric generators (WTEGs). Molybdenum disulfide (MoS₂) has been reported as a noteworthy thermoelectric (TE) material because of its large intrinsic bandgap and high carrier mobility. In this work, Cu-doped two-dimensional layered MoS₂ nanosheets were grown on carbon fabric (CF) via a hydrothermal method. The electrical conductivity, Seebeck coefficient, and power factor for the Cu-doped MoS₂ were found to increase with increasing temperature. The maximum Seebeck coefficient was obtained for a MoS₂ sample doped with 4 at% of Cu (CM4) was ∼10 μV/K at 303 K and ∼13 μV/K at 373 K. The enhancement in the Seebeck coefficient was attributed to an energy-filtering effect caused by the interfacial barrier between MoS₂ and Cu. In addition, a thermoelectric device was designed with four pairs of TE materials, where CM4 (4 at%) was used as a p-type material and Cu wire was used as an n-type material. These p- and n-type materials were connected electrically in series and thermally in parallel to generate a voltage of 190.7 μV at a temperature gradient of 8 K.

Microcatheter movement in the aneurysm due to low-profile visualized intraluminal support deployment: An in vitro study

BACKGROUND

When a microcatheter is in the aneurysm, it may move due to low-profile visualized intraluminal support (LVIS) deployment. This study was designed to determine this mechanism.

METHODS

Six silicon aneurysm models were created by combining the aneurysm location (side wall or bifurcation) and the parent vessel configuration (straight, ipsilateral bending, or contralateral bending). After adjusting the microcatheter tip position in the aneurysm by pushing or pulling, an LVIS stent was deployed to cover the aneurysm neck, and the changes in the microcatheter tip position was measured. Pushing and pulling were performed 15 times each for each model, for a total of 180 experiments.

RESULTS

In all experiments, the microcatheter tip moved with LVIS deployment. The total movement distance was 3.00±1.59 mm, which was significantly different between the push and pull groups (p = 0.049), between the three side-wall aneurysm models (p<0.0001), and between the three bifurcation aneurysm models (p<0.0001). Backward movement in the aneurysm occurred in 21% (37/180). The frequency of backward movement was significantly different between the side-wall and bifurcation aneurysm models (p = 0.0265) and between the push and pull groups (p<0.0001). The forward movement distance was significantly different between the side-wall (n = 78) and bifurcation (n = 65) aneurysm models (p<0.0001).

CONCLUSIONS

The aneurysm location, the parent vessel configuration, and adjustment of the microcatheter tip position by pushing or pulling may affect the total movement distance and forward/backward movement of the microcatheter tip due to LVIS deployment.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Low troponin I levels predict the presence of arrhythmia-induced cardiomyopathy in patients with atrial fibrillation and left ventricular systolic dysfunction

Successful atrial fibrillation (AF) ablation can improve reduced left ventricular ejection fraction (LVEF) with AF, which is defined as arrhythmia-induced cardiomyopathy (AIC). However, it is difficult to pre-procedurally predict the presence of AIC. We aimed to explore the pre-procedural predictors of AIC in patients with AF and reduced LVEF. This study included 60 patients with a reduced LVEF (LVEF < 50%; 69.1 ± 8.8 years; 45 men) who underwent successful AF ablation. Responders were defined as patients whose LVEF post-procedurally improved to the normal range (≥ 50%). Multivariate analysis revealed that the log-transformed pre-procedural troponin I (TnI) levels (odds ratio [OR] = 0.059; 95% confidence interval [CI] = 0.0052-0.42, p = 0.003) and age (OR = 0.91; 95% CI = 0.82-1.00, p = 0.044) were independent predictors of post-procedural LVEF recovery; further, low TnI levels (< 11.1 pg/ml) predicted LVEF recovery (sensitivity, 79.1%; specificity, 76.5%; positive predictive value, 89.5%; and negative predictive value, 59.1%). There were no significant differences in TnI levels between the baseline and 1 month after the procedure. However, four patients with high baseline TnI levels showed a > 50% reduction in the TnI levels post-procedurally, with three of these patients showing LVEF recovery. Low pre-procedural TnI levels can predict LVEF recovery after successful AF ablation in patients with reduced LVEF.