Nomogram-based geometric and hemodynamic parameters for predicting the growth of small untreated intracranial aneurysms.

Previous studies have shown that the growth status of intracranial aneurysms (IAs) predisposes to rupture. This study aimed to construct a nomogram for predicting the growth of small IAs based on geometric and hemodynamic parameters. We retrospectively collected the baseline and follow-up angiographic images (CTA/ MRA) of 96 small untreated saccular IAs, created patient-specific vascular models and performed computational fluid dynamics (CFD) simulations. Geometric and hemodynamic parameters were calculated. A stepwise Cox proportional hazards regression analysis was employed to construct a nomogram. IAs were stratified into low-, intermediate-, and high-risk groups based on the total points from the nomogram. Receiver operating characteristic (ROC) analysis, calibration curves, decision curve analysis (DCA) and Kaplan-Meier curves were evaluated for internal validation. In total, 30 untreated saccular IAs were grown (31.3%; 95%CI 21.8%-40.7%). The PHASES, ELAPSS, and UIATS performed poorly in distinguishing growth status. Hypertension (hazard ratio [HR] 4.26, 95%CI 1.61-11.28; P = 0.004), nonsphericity index (95%CI 4.10-25.26; P = 0.003), max relative residence time (HR 1.01, 95%CI 1.00-1.01; P = 0.032) were independently related to the growth status. A nomogram was constructed with the above predictors and achieved a satisfactory prediction in the validation cohort. The log-rank test showed significant discrimination among the Kaplan-Meier curves of different risk groups in the training and validation cohorts. A nomogram consisting of geometric and hemodynamic parameters presented an accurate prediction for the growth status of small IAs and achieved risk stratification. It showed higher predictive efficacy than the assessment tools.

Application of high-resolution magnetic resonance vessel wall image in the treatment of M1 segment stenosis of middle cerebral artery.

OBJECTIVE: To investigate the application of high-resolution magnetic resonance vessel wall image (HRMR-VWI) in treating middle cerebral artery (MCA) M1 segment stenosis. METHODS: We retrospectively analyzed preoperative clinical data, imaging data, preoperative evaluation, stent procedure, and postoperative complications in 35 patients with atherosclerotic stenosis of the MCA M1 segment. And the 30-day postoperative mortality and disability and the 12-month restenosis were followed up. RESULTS: There were 21 males and 14 females, with a median age of 55 and a median duration of 1 month from onset to stenting. DSA confirmed that the stenosis locates in the M1 segment, with a stenosis degree of (75.00 ± 17.15) %, a stenosis length of (4.34 ± 1.51) mm, and a blood vessel diameter of (2.25 ± 0.42) mm. After the operation, there was 1 case of death after a craniotomy to remove hematoma + decompression due to reperfusion hemorrhage. There were two technical complications during the procedure (1 case of asymptomatic occlusion of the A1 segment due to the covering of stent at the initial part of A1, 1 case of intraparenchymal hematoma in the temporal lobe due to penetrating distal small blood vessel with guide wire). CONCLUSION: HRMR-VWI is of great value in observing plaques' location, morphology, and stability. It can improve the safety and effectiveness of stenting treatment of MCA M1 segment stenosis.

Hybrid Surgery for Revascularization of Chronic Occlusion of Internal Carotid Artery.

OBJECTIVE: The aim of this study was to conclude the safety and effectiveness of hybrid surgery for revascularization of chronic occlusion of internal carotid artery (COICA). METHODS: A total of 56 COCIA patients underwent hybrid surgery (carotid endarterectomy+carotid artery stenting) from September 2017 to September 2021 in our department. The clinical material and radiology data (preoperation and postoperation) were retrospectively analyzed to conclude the safety and effectiveness of hybrid surgery for revascularization of COICA. RESULTS: All 56 patients underwent hybrid surgery got revascularization successfully (with a successful rate of 100%) and improved intracranial blood flow. The computed tomography perfusion results indicate that the postoperative cerebral blood flow perfusion of the patient is significantly improved compared with before surgery. In 1 patient, postoperative brain magnetic resonance imaging within 24 hours showed spotted fresh infarction with head magnetic resonance imaging, without any clinical symptoms; 3 patients developing symptoms of ipsilateral neural-functional defect (hypoglossal nerve, superior laryngeal nerve, and mandibular branch of facial nerve, respectively), 2 weeks later the symptoms were disappeared. Imaging study at 3 and 6 months during the follow-up showed no abnormalities. CONCLUSION: Hybrid surgery is safe and effective for revascularization of COICA.

Prevalence and prognosis of acute ischemic stroke coexisting with unruptured intracranial aneurysms.

Objectives: The prevalence of unruptured intracranial aneurysms (UIAs) in the acute ischemic stroke (AIS) cohort is probably higher than in the general population. This study investigated the prevalence of UIAs in AIS patients and the management risk and prognosis when treating AIS. Methods: From January 2020 to January 2023, we conducted a single-center retrospective study at Tianjin Huanhu Hospital. Each patient underwent both brain MRI and MRA/CTA to diagnose AIS and UIAs. Clinical, radiologic, and therapeutic data during hospitalization and prognosis were analyzed. Propensity-score matching (PSM) was performed to evaluate the risk of in-hospital adverse events, unfavorable outcomes at discharge when receiving post-stroke treatment and stroke recurrence. Results: In all, 2,181 AIS patients were included, of whom 270 had UIAs (12.4%; 95%CI 11.0-13.8%). From the unmatched and matched cohort, the incidence of in-hospital adverse events and unfavorable outcomes at discharge in patients with UIAs were not significantly different; the risk of stroke recurrence was significantly higher in patients with UIAs than in those without (unmatched: aHR, 1.71 [1.08-2.70]; matched: aHR, 2.55 [1.16-5.58]). Multivariable Cox regression models showed that aneurysm size and the presence of homoregional infarction associated with higher risk of recurrence (unmatched: aHR, 1.31 [1.21-1.41] and aHR, 3.50 [1.52-8.10]; matched: aHR, 1.28 [1.18-1.40]; p < 0.001 and aHR, 3.71 [1.12-12.34]). Conclusion: The UIAs may not increase the risk of in-hospital adverse events and unfavorable outcomes at discharge in receiving post-stroke treatment, but it may associated with a high risk of stroke recurrence.

Analysis of risk factors of pituitary neoplasms invading the sphenoidal sinus.

High-resolution computed tomography (HR-CT) can more effectively discern the relationship between pituitary neoplasms (PNs) and neighboring anatomical structures. Moreover, pathological features can facilitate a more accurate determination of the growth pattern of PNs. Consequently, integrating imaging and pathological data might enhance our predictive capability regarding the growth patterns of PNs and aid in the formulation of surgical plans. We compared HR-CT images of 54 patients and 52 volunteers. Using ITK-SNAP software, we segmented and reconstructed the anatomical features of the sphenoidal sinus (SS) and calculated its volume. A comparative analysis of the invasive attributes of the 54 PNs was carried out based on clinical features and pathological data. The average volume of the SS in the volunteer group was 11.05 (8.10) mL, significantly larger than that of the PNs group at 7.45 (4.88) mL (P = .005). The postsellar type was the most common pneumatization type, and a significantly higher proportion in the PNs group exhibited a depressed saddle base (83.3%). A notable male predominance was observed for SS invasion in the PNs group (72.7%), with the Ki-67 antigen and maximum diameter significantly higher (P < .05), showing a positive correlation. The optimal cutoff points for Ki-67 antigen and the maximum diameter of PNs were 3.25% (AUC = 0.754, Sensitivity 54.5%, Specificity 90.6%) and 24.5 mm (AUC = 0.854, Sensitivity 86.4%, Specificity 78.1%), respectively. The type of pneumatization and the morphology of the sellar-floor serve as anatomical foundations for SS invasion. Factors such as the Ki-67 antigen, the maximum diameter of PNs, and high-risk sub-types constitute risk factors for PNs invasion into the SS. These insights are of significant utility for clinicians in crafting treatment strategies for PNs.

Clinical characteristics of spontaneous intracranial basal ganglia hemorrhage and risk factors for hematoma expansion in the plateaus of China.

Background and purpose: The clinical features of intracranial cerebral hemorrhage (ICH) and the risk factors for hematoma expansion (HE) have been extensively studied. However, few studies have been performed in patients who live on a plateau. The natural habituation and genetic adaptation have resulted in differences in disease characteristics. The purpose of this study was to investigate the differences and consistency of clinical and imaging characteristics of patients in the plateaus of China compared with the plains, and to analyze the risk factors for HE of intracranial hemorrhage in the plateau patients. Methods: From January 2020 to August 2022, we undertook a retrospective analysis of 479 patients with first-episode spontaneous intracranial basal ganglia hemorrhage in Tianjin and Xining City. The clinical and radiologic data during hospitalization were analyzed. Univariate and multivariate logistic regression analyzes were used to assess the risk factors for HE. Results: HE occurred in 31 plateau (36.0%) and 53 plain (24.2%) ICH patients, and HE was more likely to occur in the plateau patients compared with the plain (p = 0.037). The NCCT images of plateau patients also showed heterogeneity of hematoma imaging signs, and the incidence of blend signs (23.3% vs. 11.0%, p = 0.043) and black hole signs (24.4% vs. 13.2%, p = 0.018) was significantly higher than in the plain. Baseline hematoma volume, black hole sign, island sign, blend sign, and PLT and HB level were associated with HE in the plateau. Baseline hematoma volume and the heterogeneity of hematoma imaging signs were independent predictors of HE in both the plain and plateau. Conclusion: Compared with the plain, ICH patients in the plateau were more prone to HE. The patients showed the same heterogeneous signs on the NCCT images as in the plain, and also had predictive value for HE.

Emergent Management of Tandem Occlusions in Anterior Circulation Stroke: A Single-Centre Experience.

OBJECTIVE: For anterior circulation tandem occlusions, the optimal management strategy for extracranial carotid lesions is controversial. We aimed to compare the efficacy and safety of acute stenting (AS) with balloon angioplasty (BA) only. METHODS: Clinical data were collected from 98 patients with anterior circulation tandem occlusion who underwent endovascular treatment at our center. Of these patients, 64 and 34 were assigned to the AS and BA groups, respectively. The clinical characteristics and outcome data of the 2 groups were analyzed and compared. RESULTS: The proportion of patients with good outcomes was 59.2%. The AS group had a higher rate of successful recanalization (98.4% vs. 82.4%, P = 0.007) and a lower rate of occlusion of the responsible vessel at 90 days (14.1% vs. 32.4%, P = 0.039) than the BA group. The AS group was also significantly better than the BA group in terms of good outcomes (67.2% vs. 44.1%, P = 0.027), but there was no significant difference between the 2 groups in terms of 90-day mortality (6.3% vs. 8.8%, P = 0.691) and asymptomatic intracranial hemorrhage (6.3% vs. 5.9%, P = 1.000). Lower baseline National Institutes of Health Stroke Scale scores were associated with good outcomes (P < 0.001), and the presence of symptomatic intracranial hemorrhage was associated with 90-day mortality (P = 0.003). CONCLUSIONS: Acute stent placement in patients with acute ischemic stroke due to anterior circulation tandem occlusion may have a better outcome than BA alone, and the safety of both approaches is comparable.

A clinical application study of a stent placement assessment.

BACKGROUND: Atherosclerotic acute carotid occlusion is a specific type of stroke, and controversy exists regarding the surgical strategy, that is, whether an internal carotid artery stent should be placed immediately after opening the occluded vessel. There is no objective evaluation system for this procedure. In a previous study, we summarized an evaluation decision system Emergent Carotid Artery Stent placement decision Evaluation System (ECASES) for emergency stent placement. STUDY DESIGN: This is a prospective, single-center, randomized controlled trial. Patients with acute ischemic stroke caused by atherosclerotic carotid artery occlusion confirmed by imaging (computed tomography/magnetic resonance angiography/digital subtraction angiography) will be randomly divided into the study and control groups, with 101 patients in each group. The study group will undergo surgery according to the ECASES system and the control group will undergo surgery according to the operator's experience. The postoperative outcomes of the 2 groups will be compared. STUDY OUTCOMES: Primary outcome: Neurological functional status (modified Rankin Scale and National Institutes of Health Stroke Scale scores) of patients 90 days postoperatively. Secondary outcomes: neurological function changes, hemorrhage events, cerebral edema, postoperative modified treatment in cerebral infarction grade, new cerebral infarction, and reocclusion of responsible vessels. DISCUSSION: Currently, no prospective controlled data exist regarding the efficacy and safety of carotid stenting in the acute phase. Previously, we had developed an ECASES stent placement system for acute carotid artery occlusion. The present study will evaluate the efficacy and safety of ECASES in a randomized, double-blind prospective study and clarify its guiding significance in acute atherosclerotic carotid artery occlusion surgery.

Case Report: Trigeminocardiac Reflex in Endovascular Recanalization of Intracranial Internal Carotid Artery Occlusion.

Background: The trigeminocardiac reflex (TCR) is a unique brainstem reflex that manifests as sudden negative hemodynamic changes. Although rare, TCR may develop during interventional neuroradiology procedures. Intracranial internal carotid artery occlusion (ICAO) is a cause or risk factor of ischemic stroke. Endovascular recanalization is an effective treatment for intracranial ICAO. The occurrence of TCR during the endovascular treatment of intracranial ICAO has not been reported previously. Methods: We identified and reviewed four intracranial ICAO cases who suffered a sudden negative hemodynamic change during endovascular therapy at our hospital between March 2019 and December 2020. Results: There were five sudden heart rate and/or blood pressure drops in the four cases; all occurred just after contrast agents were injected. Some angioarchitectural characteristics were common among the four cases. First, the intracranial internal carotid artery distal to the ophthalmic artery was occluded, leaving the ophthalmic artery as the only outflow tract. Second, there were obstructive factors proximal to the end of the guiding catheter, including a vasospasm or dilated balloon. This type of angioarchitecture with a limited outflow tract creates a "blind alley." The five negative hemodynamic events all recovered: two spontaneously and three after drug administration. Postoperatively, two of the four patients developed ocular symptoms. Conclusions: Intracranial ICAOs may produce a distinctive angioarchitecture, such as a blind alley, that predisposes patients to TCR. Surgeons should pay special attention to the possibility of TCR during the endovascular recanalization of intracranial ICAO. Low-pressure contrast injections should be attempted, and anticholinergics should be ready for use.

The application and perspective of hyperbaric oxygen therapy in acute ischemic stroke: From the bench to a starter?

Stroke has become a significant cause of death and disability globally. Along with the transition of the world's aging population, the incidence of acute ischemic stroke is increasing year by year. Even with effective treatment modalities, patients are not guaranteed to have a good prognosis. The treatment model combining intravenous thrombolysis/endovascular therapy and neuroprotection is gradually being recognized. After the clinical translation of pharmacological neuroprotective agents failed, non-pharmacological physical neuroprotective agents have rekindled hope. We performed a literature review using the National Center for Biotechnology Information (NCBI) PubMed database for studies that focused on the application of hyperbaric oxygen therapy in acute ischemic stroke. In this review, we present the history and mechanisms of hyperbaric oxygen therapy, focusing on the current status, outcomes, current challenges, perspective, safety, and complications of the application of hyperbaric oxygen in animal experiments and human clinical trials. Hyperbaric oxygen therapy, a non-pharmacological treatment, can improve the oxygenation level at the ischemic lesions in increased dissolved oxygen and oxygen diffusion radius to achieve salvage of neurological function, giving a new meaning to acute ischemic stroke.

Mechanism of Stat1 in the neuronal Ca2+ overload after intracerebral hemorrhage via the H3K27ac/Trpm7 axis.

Intracerebral hemorrhage (ICH) is classified as a subtype of stroke and calcium (Ca2+) overload is a catalyst for ICH. This study explored the mechanisms of Stat1 (signal transducer and activator of transcription 1) in the neuronal Ca2+ overload after ICH. ICH mouse models and in vitro cell models were established. Stat1 and transient receptor potential melastatin 7 (Trpm7) were detected upregulated in ICH models. Afterward, the mice were infected with the lentivirus containing sh-Stat1, and HT22 cells were treated with si-Stat1 and the lentivirus containing pcDNA3.1-Trpm7. The neurological functional impairment, histopathological damage, and Nissl bodies in mice were all measured. HT22 cell viability and apoptosis were identified. The levels of Ca2+, Trpm7 mRNA, H3K27 acetylation (H3K27ac), CaMKII-α, and p-Stat1 protein in the tissues and cells were determined. We found that silencing Stat1 alleviated ICH damage and repressed the neuronal Ca2+ overload after ICH. H3K27ac enrichment in the Trpm7 promoter region was examined and we found that p-Stat1 accelerated Trpm7 transcription via promoting H3K27ac in the Trpm7 promoter region. Besides, Trpm7 overexpression increased Ca2+ overload and aggravated ICH. Overall, p-Stat1 promoted Trpm7 transcription and further aggravated the Ca2+ overload after ICH.NEW & NOTEWORTHY We found Stat1 promotes Trpm7 transcription by promoting H3K27 acetylation and thus promotes calcium overload of neurons after intracerebral hemorrhage.

Anterior Circulation Acute Ischemic Stroke in the Plateau of China: Risk Factors and Clinical Characteristics.

Background and Purpose: Acute ischemic stroke has a high incidence in the plateau of China. It has unique characteristics compared to the plains, and the specific relationship with altitude has not yet been appreciated. This study aimed to investigate the specificity of the plateau's anterior circulation acute ischemic stroke in China. Methods: To retrospectively collect clinical data of patients with first-episode acute ischemic stroke in the anterior circulation in Tianjin and Xining city. The differences in clinical presentation, laboratory, and imaging examinations were compared. Results: Patients at high altitudes showed a significant trend toward lower age (61.0 ± 10.2 vs. 64.8 ± 8.1, P = 0.010) and had a history of dyslipidemia, higher levels of inflammatory markers, erythrocytosis, and alcohol abuse. The main manifestations were higher diastolic blood pressure (85.5 ± 14.0 mmHg vs. 76.8 ± 11.6 mmHg, P < 0.001), triglycerides [2.0 (1.8) mmol/L vs. 1.3 (0.9) mmol/L, P < 0.001], CRP [4.7 (4.4) mg/L vs. 2.1 (1.9) mg/L, P < 0.001], homocysteine levels [14.5 (11.7) µmol/L vs. 11.2 (5.2) µmol/L, P < 0.001]; larger infarct volume [3.5 (4.8) cm3 vs. 9.0 (6.9) cm3, P < 0.001] and worse prognosis. Patients at high altitudes had higher atherosclerotic indexes in cIMT and plaque than those in plains. Conclusions: The natural habituation and genetic adaptation of people to the particular geo-climatic environment of the plateau have resulted in significant differences in disease characteristics. Patients with the anterior circulation acute ischemic stroke in the plateau show more unfavorable clinical manifestations and prognosis. This study provides a preliminary interpretation of the effects of altitude and suggests developing preventive and therapeutic protocol measures that are more appropriate for the plateau of China.

Emergency bedside evacuation of a subset of large postoperative epidural hematomas after neurosurgical procedures.

Postoperative epidural hematoma (POEDH) is a known complication after neurosurgical procedures. Large POEDHs are life-threatening and require emergency evacuation, and open surgery is the mainstay of treatment. Most of POEDHs are hyperdense on computed tomography (CT). We herein report a subset of POEDHs requiring evacuation, which presented with isodense features on CT. The presenting symptoms of patients were severe headache accompanied by nausea and vomiting as well as unilateral limb weakness (n = 1) and consciousness disorder (n = 4). The Glasgow coma score of the patients was 8.4 ±â€Š3.5. All patients underwent emergency bedside burr hole evacuation through a tube, rather than open surgery. The meantime for the bedside procedures is 6.0 ±â€Š1.5 minutes. All 5 POEDHs were proven liquid and evacuated successfully. All patients recovered quickly with good outcomes. We concluded that the isodensity of the POEDHs on CT represent their liquid nature. Bedside burr hole evacuation through a tube may be a recommendable method for this subset of POEDHs requiring evacuation. Thus, an open surgery and general anesthesia may be avoided.

Duplicated middle cerebral artery origin with an aneurysm.

RATIONALE: Middle cerebral artery (MCA) anomalies are relatively rare and often related to aneurysms. Familiarity with these anomalies is important in resolving problems that arise in the complex angioarchitecture. Reports often describe that aneurysms that are related to accessory or duplicated MCA are often located at its origin. PATIENT CONCERNS: A 59-year-old man presented with a headache for 10 days, without nausea and vomiting. The physical examination was negative. DIAGNOSIS: A computed tomography (CT) scan revealed an intracerebral hematoma in the deep right frontal lobe, near the caudate nucleus. Digital subtraction angiography (DSA) revealed an anomalous duplicated origin of the right MCA, with occlusion of the main MCA trunk as well as twisting and dilation of the accessory MCA trunk. A wide-necked aneurysm was located at a sharp curve of the tortuous accessory MCA trunk. A ruptured aneurysm related to a duplicated MCA origin was diagnosed. INTERVENTIONS: Open surgery was rejected by the patient; hence, palliative endovascular coil embolization of the larger daughter sac was performed. OUTCOMES: The postoperative course was uneventful. There was no rebleeding at 8-months follow-up. LESSONS: MCA anomalies are relatively rare and often related to aneurysms. It is important to be familiar with these anomalies as related lesions often manifest within a complex angioarchitecture. Aneurysms at the trunk of an anomalous MCA are a rare entity and open surgery may be recommended.

Double microcatheter technique for coil embolization of small aneurysms with unfavorable configurations: A comparative study of the aneurysms that are ≤3 mm or >3 mm.

INTRODUCTION: The endovascular coiling of small ruptured aneurysms with difficult geometries presents a significant treatment challenge. We report our initial experience and the technical details of dual microcatheter coil embolizations that were applied in these difficult lesions. METHOD AND RESULTS: Eighty-five small aneurysms (<7 mm) that exhibited difficult configurations, such as a wide neck or an important branch vessel arising from the fundus, were successfully treated using a dual microcatheter technique. The packing attenuation, adverse events during the procedures, and angiographic occlusions from 21 very small aneurysm (≤3 mm) were recorded and compared with our coiling results of 64 small aneurysms (>3 mm, <7 mm). There were no significant differences in intraprocedural ruptures or procedure-related thromboembolisms between the two groups. At the last post-procedure clinical follow-up, a good clinical outcome (an modified Rankin Scale (mRS) of 0-2) was observed in 18 of the patients (85.7%). The recanalization rates at follow-up were significantly lower in the very small aneurysm group compared to the small aneurysm group (p < 0.05) and the mean packing density in the very small aneurysm group was significantly higher compared to the small aneurysm group (35.2% vs 24.8%, p < 0.05). CONCLUSION: The dual technique was feasible, safe, and effective for coil embolization of aneurysms with difficult configurations and, in particular, it provided an alternative option for treating very small aneurysms.

The combinational use of dual microcatheter technique and new hypersoft helical coil for endovascular treatment of tiny intracranial aneurysm with difficult geometry.

The endovascular coiling of very small ruptured aneurysms with difficult geometry presents a significant treatment challenge because of potential dangerous complications, such as intraprocedural ruptures. We report our initial experience with the use of a dual microcatheter technique, combined with new hypersoft helical coils, for the treatment of these difficult lesions. Fourteen very small aneurysms with a maximum diameter of ≤3 mm that presented difficult configurations, such as a wide neck or an important branch vessel arising from the fundus, were identified using digital subtraction angiography. These lesions were successfully treated using a dual microcatheter technique and new hypersoft helical coils. There were no intraprocedural ruptures or procedure-related thromboembolisms. Complete or near-complete occlusions were achieved in all of the lesions. A Raymond score of RS 1 was achieved in eight of the aneurysms (57.1%) and an RS 2 was achieved in six of the aneurysms (42.9%). The mean packing density was 35.5%. At the last post-procedure clinical follow-up, a good clinical outcome (a modified Rankin scale score of 0-2) was observed in 11 of the patients (91.7%). The result of angiographic follow up in 11 cases showed two recanalized aneurysms. The use of the dual microcatheter technique and new hypersoft helical coil allowed for stable coil framing and good packing in geometrically difficult tiny aneurysms and presented a low rate of adverse events related to the procedure. The technique provided an efficient strategy for treating very small aneurysms with difficult configurations and high risks.

Endovascular coiling of small intracranial aneurysms using a very soft bare platinum coil: A comparison of the packing performance of new and old HyperSoft® helical coils.

AIMS: Soft and small coils are known to be appropriate for the treatment of small aneurysms. The purpose of this study was to determine whether the new HyperSoft® helical coil, which is softer and smaller than its predecessors, has any effect on the packing performance in a matched-pair study with an old HyperSoft® helical coil. MATERIALS AND METHODS: Thirty-six consecutive patients harboring 43 cerebral aneurysms treated with new HyperSofts were included in this study. Forty-one aneurysms treated with old HyperSofts were identified from our database as matched controls based on similar volumes and locations. Packing attenuation, adverse events during the procedures, and angiographic occlusions were observed and compared between the two groups. RESULTS: The mean packing density was significantly higher in the new HyperSoft® group compared to the control group (35.5% vs. 26.9%), and a larger proportion of the aneurysms embolized with the 1.5 mm size coil, which has higher packing density. There was no difference in immediate and midterm angiographic outcomes. There was no difference in the rate of intraprocedural perforation, but there was no intraprocedural rupture related to the 1.5 mm coil. CONCLUSIONS: The use of new HyperSoft® helical coils allows higher packing density comparable with the old technology. New HyperSoft® coils, especially those with 1.5 mm loop diameter, can be expected to fill smaller residual spaces in small aneurysms and may be helpful in preventing recanalization.