Dietary Iron Restriction Protects against Aneurysm Rupture in a Mouse Model of Intracranial Aneurysm.

INTRODUCTION: Iron accumulation in vessel walls induces oxidative stress and inflammation, which can cause cerebrovascular damage, vascular wall degeneration, and intracranial aneurysmal formation, growth, and rupture. Subarachnoid hemorrhage from intracranial aneurysm rupture results in significant morbidity and mortality. This study used a mouse model of intracranial aneurysm to evaluate the effect of dietary iron restriction on aneurysm formation and rupture. METHODS: Intracranial aneurysms were induced using deoxycorticosterone acetate-salt-induced hypertension and a single injection of elastase into the cerebrospinal fluid of the basal cistern. Mice were fed an iron-restricted diet (n = 23) or a normal diet (n = 25). Aneurysm rupture was detected by neurological symptoms, while the presence of intracranial aneurysm with subarachnoid hemorrhage was confirmed by post-mortem examination. RESULTS: The aneurysmal rupture rate was significantly lower in iron-restricted diet mice (37%) compared with normal diet mice (76%; p < 0.05). Serum oxidative stress, iron accumulation, macrophage infiltration, and 8-hydroxy-2'-deoxyguanosine in the vascular wall were lower in iron-restricted diet mice (p < 0.01). The areas of iron positivity were similar to the areas of CD68 positivity and 8-hydroxy-2'-deoxyguanosine in both normal diet and iron-restricted diet mouse aneurysms. CONCLUSIONS: These findings suggest that iron is involved in intracranial aneurysm rupture via vascular inflammation and oxidative stress. Dietary iron restriction may have a promising role in preventing intracranial aneurysm rupture.

Flow diversion of ruptured intracranial aneurysms: a single-center study with a standardized antithrombotic treatment protocol.

BACKGROUND: The use of antithrombotic medication following acute flow diversion for a ruptured intracranial aneurysm (IA) is challenging with no current guidelines. We investigated the incidence of treatment-related complications and patient outcomes after flow diversion for a ruptured IA before and after the implementation of a standardized antithrombotic medication protocol. METHODS: We conducted a single-center retrospective study including consecutive patients treated for acutely ruptured IAs with flow diversion during 2015-2023. We divided the patients into two groups: those treated before the implementation of the protocol (pre-protocol) and those treated after the implementation of the protocol (post-protocol). The primary outcomes were hemorrhagic and ischemic complications. A secondary outcome was clinical outcome using the modified Ranking Scale (mRS). RESULTS: Totally 39 patients with 40 ruptured IAs were treated with flow diversion (69% pre-protocol, 31% post-protocol). The patient mean age was 55 years, 62% were female, 63% of aneurysms were in the posterior circulation, 92% of aneurysms were non-saccular, and 44% were in poor grade on admission. Treatment differences included the use of glycoprotein IIb/IIIa inhibitors (pre-group 48% vs. post-group 100%), and the use of early dual antiplatelets (pre-group 44% vs. 92% post-group). The incidence of ischemic complications was 37% and 42% and the incidence of hemorrhagic complications was 30% and 33% in the pre- and post-groups, respectively, with no between-group differences. There were three (11%) aneurysm re-ruptures in the pre-group and none in the post-group. There were no differences in mortality or mRS 0-2 between the groups at 6 months. CONCLUSION: We found no major differences in the incidence of ischemic or hemorrhagic complications after the implementation of a standardized antithrombotic protocol for acute flow diversion for ruptured IAs. There is an urgent need for more evidence-based guidelines to optimize antithrombotic treatment after flow diversion in the setting of subarachnoid hemorrhage.

Fecal calprotectin is a novel biomarker to predict the clinical outcomes of patients with ruptured intracranial aneurysm.

BACKGROUND: Intracranial aneurysm (IA) is a common cerebrovascular disease and the leading cause of spontaneous subarachnoid hemorrhage. Recent evidence suggests that gut microbiota is involved in the pathophysiological process of IA through the gut-brain axis. However, the role of gut inflammation in the development of IA has yet to be clarified. Our study aimed to investigate whether fecal calprotectin (FC) level, a sensitive marker of gut inflammation, is correlated with the development of IA and the prognosis of patients with ruptured IA (RIA). METHODS: 182 patients were collected from January 2022 to January 2023, including 151 patients with IA and 31 healthy individuals. 151 IA patients included 109 patients with unruptured IA (UIA) and 42 patients with RIA. The FC level was measured by enzyme-linked immunosorbent assay. Other detailed information was obtained from an electronic medical record system. RESULTS: Compared with healthy controls, the FC levels in patients with IA were increased (P < 0.0001). Patients with RIA had significantly higher FC levels than UIA patients (P < 0.0001). Moreover, the FC level in RIA patients with unfavorable outcomes was higher than in RIA patients with favorable outcomes. Logistic regression analysis showed that the elevated FC level was an independent risk factor for a 3-month poor prognosis in patients with RIA (OR=1.005, 95% CI = 1.000 -1.009, P = 0.044). CONCLUSION: Fecal calprotectin level is significantly elevated in IA patients, especially those with RIA. FC is a novel biomarker of 3-month poor outcomes in RIA patients.

Rapidly Growing and Ruptured Great Saphenous Vein Aneurysm in a Liver Transplant Patient.

Venous aneurysms are rare vascular malformations that can lead to significant clinical complications, including thrombosis, pulmonary embolism, rupture, and even fatal outcomes when not promptly and adequately managed. This case report presents a liver transplant patient under immunosuppressive therapy who developed a rapidly progressing great saphenous vein aneurysm, ultimately requiring urgent surgical intervention due to acute bleeding from the ruptured aneurysm. Immunosuppression emerges as a potential key factor in the formation and rapid growth of the aneurysm, with the pathophysiological mechanism potentially involving increased expression of specific matrix metalloproteinases. Further research is warranted to gain a better understanding of the role of immunosuppression in the development of venous aneurysms.

Heightened activation of embryonic megakaryocytes causes aneurysms in the developing brain of mice lacking podoplanin.

During early embryonic development in mammals, including humans and mice, megakaryocytes (Mks) first originate from primitive hematopoiesis in the yolk sac. These embryonic Mks (eMks) circulate in the vasculature with unclear function. Herein, we report that podoplanin (PDPN), the ligand of C-type lectin-like receptor (CLEC-2) on Mks/platelets, is temporarily expressed in neural tissue during midgestation in mice. Loss of PDPN or CLEC-2 resulted in aneurysms and spontaneous hemorrhage, specifically in the lower diencephalon during midgestation. Surprisingly, more eMks/platelets had enhanced granule release and localized to the lower diencephalon in mutant mouse embryos than in wild-type littermates before hemorrhage. We found that PDPN counteracted the collagen-1-induced secretion of angiopoietin-1 from fetal Mks, which coincided with enhanced TIE-2 activation in aneurysm-like sprouts of PDPN-deficient embryos. Blocking platelet activation prevented the PDPN-deficient embryo from developing vascular defects. Our data reveal a new role for PDPN in regulating eMk function during midgestation.

A shift from open to endovascular repair in the treatment of ruptured middle cerebral artery aneurysms: a single institution experience.

PURPOSE: Middle cerebral aneurysms were underrepresented in the two largest trials (BRAT and ISAT) for the treatment of ruptured intracranial aneurysms. Recent institutional series addressing the choice between endovascular or open repair for this subset of aneurysms are few and have not yielded a definitive conclusion. We compare clinical outcomes of patients presenting with acute subarachnoid hemorrhage from ruptured middle cerebral artery aneurysms undergoing either open or endovascular repair. METHODS: We conducted a retrospective review of 138 consecutive patients with ruptured middle cerebral artery aneurysms admitted into our institution from January 2008 to March 2019 to compare endovascular and open surgical outcomes. RESULTS: Of the ruptured middle cerebral artery aneurysms, 57 underwent endovascular repair while 81 were treated with open surgery. Over the study period, there was a notable shift in practice toward more frequent endovascular treatment of ruptured MCA aneurysms (31% in 2008 vs. 91% in 2018). At discharge (49.1% vs 29.6%; p = .002) and at 6 months (84.3% vs 58.6%; p = 0.003), patients who underwent endovascular repair had a higher proportion of patients with good clinical outcomes (mRS 0-2) compared to those undergoing open surgery. Long-term follow-up data (endovascular 54.9 ± 37.9 months vs clipping 18.6 ± 13.4 months) showed no difference in rebleeding (1.8% vs 3.7%, p = 0.642) and retreatment (5.3% vs 3.7%, p = 0.691) in both groups. CONCLUSION: Our series suggests equipoise in the treatment of ruptured middle cerebral artery aneurysms and demonstrates endovascular repair as a potentially feasible treatment strategy. Future randomized trials could clarify the roles of these treatment modalities.

Supraorbital eyebrow approach and pterional approach in surgical treatment of ruptured and unruptured aneurysms: a propensity score-matched analysis.

The aim of this study is to reveal efficacy and efficiency of the supraorbital eyebrow approach (SEA) in clipping ruptured and unruptured aneurysms where both SEA and pterional approach (PA) are considered feasible by comparing SEA and PA using propensity score matching. A total of 229 patients who underwent surgical clipping of an aneurysm from 2013 to 2022 and met inclusion criteria were recruited in the study. A study group of 67 patients treated via the SEA and a comparison group of 162 patients treated via the PA were formed. Then, the subgroups of 66 patients each, with balanced incoming factors, were analyzed using the propensity score technique. The safety and efficacy endpoints were compared. Successful clipping was achieved in all cases of both groups. There were no patients in the SEA group who required conversion to the standard craniotomy. There were no procedure-related deaths in this series. No patient experienced early or late rebleeding in either group. Mean blood loss volume in the SEA group was lower than in the PA group by approximately 77.5 ml (p < 0.001). There were favorable differences in the SEA group regarding postoperative neurological deficit (p = 0.016), postoperative epileptic seizure rate (p = 0.013), ischemic and hemorrhagic complications (p = 0.028 and 0.0009, respectively), and outcomes (p < 0.001). Patients' satisfaction with cosmetic results measured by the visual analog scale was rated highly in both groups (p = 0.081). For patients where SEA provides adequate exposure, it results in safety and cosmetic outcomes not inferior to the PA.

A nomogram to predict the risk of bleeding after discharge from stent-assisted ruptured aneurysm embolization in a Chinese population.

The occurrence of bleeding events after stent-assisted embolization of a ruptured artery requiring continuous double antiplatelet therapy may seriously affect the prognosis of this group of patients. A nomogram can provide a personalized, more accurate risk estimate based on predictors. We, therefore, developed a nomogram to predict the probability of bleeding events in patients with stent-assisted ruptured aneurysm embolization. We performed a single-center retrospective analysis of data collected from patients undergoing stent-assisted ruptured aneurysm embolization between January 2018 and December 2021. Forward stepwise logistic regression was performed to identify independent predictors of adverse events of bleeding after stent-assisted embolization and to establish nomograms. Discrimination and calibration of this model were performed using the area under the ROC curve (AUC-ROC) and the calibration plot. The model is internally validated by using resampling (1000 replicates). A total of 131 patients were identified, and a total of 118 patients met the study criteria. The predictors included in the nomogram were body mass index (BMI), AAi, and MA-ADP. The model showed good resolving power with a ROC area of 0.893 (95% CI: 0.834 ~ 0.952) for this model with good calibration. The nomogram can be used to individualize, visualize, and accurately predict the risk probability of bleeding events after stent-assisted embolization of ruptured aneurysms.

Efficacy and safety of flow diverter combined with coil embolization and evidence-based antithrombotic regimen in the treatment of ruptured aneurysms.

OBJECTIVE: The use of a flow diverter (FD) in the treatment of ruptured aneurysms is limited due to the increased risk of perioperative ischemia and hemorrhagic complications. Adjunctive coil embolization and an evidence-based antithrombotic regimen may improve therapeutic safety, although evidence from relevant clinical research is limited. The authors' aim was to further assess the perioperative safety and long-term efficacy of this strategy. METHODS: Data on patients with FD insertion and coil embolization were collected retrospectively at two centers. The perioperative antithrombotic regimen consists of intraoperative tirofiban and continues for 24 hours postoperatively, with the initiation of an orally administered dual-antiplatelet regimen 4 hours prior to tirofiban cessation, rather than purposeful preoperative antiplatelet therapy. Perioperative cerebral ischemia and hemorrhagic complications and long-term aneurysm occlusion rates were recorded to evaluate the safety and efficacy of the procedure, respectively. RESULTS: In total, 67 cases were screened and 41 cases were ultimately included in this study. A total of 2 cases (4.9%) of perioperative cerebral hemorrhagic events occurred, 1 of which (2.4%) was attributable to rerupture of the aneurysm. Cerebral ischemic events were reported in 3 patients, including 1 with cortical thromboembolism and 2 with perforator occlusion of the basilar artery. A median 8-month follow-up was attained in 25 patients (61.0%), with a 92% complete or near-complete occlusion rate. CONCLUSIONS: FD insertion combined with coil embolization is a potentially safe and effective therapeutic strategy for ruptured aneurysms when accompanied with perioperative evidence-based antithrombotic therapy.

Duplicated fetal posterior cerebral artery in a patient with a ruptured fetal posterior cerebral artery aneurysm: a cerebrovascular variant.

BACKGROUND: The most common neurovascular variant is the fetal posterior cerebral artery (FPCA), in which the P1 branch is absent or hypoplastic, and the majority of P2 supply is derived from the anterior circulation. While there are reports of hyperplastic anterior choroidal arteries (AChA) with supply to the temporo-occipital and calcarine regions, no reports of a duplicated FPCA exist. METHODS: This case report describes a patient with a ruptured right FPCA aneurysm. Digital subtraction angiogram (DSA) revealed an artery with origin distal to the FPCA associated with the aneurysm. This was not consistent with a typical AChA. The FPCA associated with the aneurysm had the typical origin, course, and supply of a FPCA. The distal FPCA had a similar course of a typical FPCA with significant supply to the typical PCA territory. The patient underwent successful clipping of the aneurysm, and the duplicated FPCA was identified during the craniotomy. RESULTS: The features of this duplicate FPCA, which has not been previously described, are discussed in comparison to another variant, the hyperplastic, anomalous AChA. The artery described in this report does not fit the typical criteria of this AChA variant. Therefore, the authors outline this variant as a duplicated FPCA. CONCLUSION: Recognition of variant cerebrovascular anatomy is vital to neurosurgeons and interventional neuroradiology specialists. FPCA aneurysms require special management considerations and are often more challenging to treat. This report discusses a duplicated FPCA. To our knowledge, this is the first description of this variant. A duplicated FPCA carries important management considerations in the management of neurovascular pathology.

[Unruptured Intracranial Aneurysm:Indications and Outcomes].

Since most unruptured intracranial aneurysms(UIA)are asymptomatic, it is important to determine treatment indications. The purpose of UIA treatment is to prevent rupture and relieve the patient's mental burden. Therefore, building a good relationship between doctors and patients is a major premise for one of the indications for surgical treatments. In addition, long-term follow-up of patients is necessary because endovascular treatment has the possibility of recurrence and retreatment. Since endovascular treatment is "possible" and "suitable" is different, it is necessary to determine the treatment policy from a radical point of view.

Clinical features of tuberculous pseudoaneurysm and risk factors for mortality.

OBJECTIVES: The objective of this study was to determine the clinical features of tuberculous aneurysms and risk factors for mortality. METHODS: We reviewed all case reports of tuberculous aneurysms in the English literature from January 2000 to December 2020. The clinical features and possible risk factors for mortality were recorded and analyzed. RESULTS: In total, 174 cases of tuberculous aneurysms were identified. The morbidity of men was more than twice that of women. Male patients (51.47 ± 20.67 years) were older than female patients (39.52 ± 20.23 years; P < .05). The rupture rate in women (69.2%) was higher than that in men (48.8%). Tuberculosis (TB)-induced aneurysms often spontaneously ruptured 1.41 to 3.01 months after the onset of TB symptoms without any treatment, and Bacillus Calmette-Guerin (BCG)-induced aneurysms often spontaneously ruptured 10.51 to 26.49 months after BCG administration. The morbidity of large artery aneurysms was nearly twice that of middle artery aneurysms. However, middle artery aneurysms were more likely to rupture (75.4%) than large artery aneurysms (43.5%; P < .05). The rupture rate of BCG-induced aneurysms (37.0%) was lower than that of TB-induced aneurysms, regardless of whether there was a TB history (56.7%) or not (57.7%). Symptoms of TB occurred in 63.2% of patients, but only 8.6% of patients had both symptoms of TB and aneurysmal mass effects. Pain was the most common atypical clinical manifestation (50.0%). The Cox proportional hazards regression analysis and Kaplan-Meier estimator showed that rupture and no combined therapy were risk factors for mortality. CONCLUSIONS: Tuberculous aneurysms seemingly shared the same demographic characteristics as common aneurysms. The clinical features of TB-induced aneurysms were different from those of BCG-induced aneurysms in terms of the aneurysm location and rupture rate. Tuberculous aneurysms may occur at any site of the cardiovascular system with a preponderance for large arteries. The changeable clinical manifestations were important index for diagnosis, but focusing only on clinical manifestations may lead to a missed diagnosis. The combination of anti-TB medications and surgery before aneurysm rupture may provide the best prognosis.

Intraoperative rupture of intracerebral aneurysm immediately after meningioma resection: a case report.

BACKGROUND: Meningiomas and unruptured cerebral aneurysms (UCAs) rarely coexist. However, the treatment strategy remains to be fully elucidated. This report is a first report that UCA related to the tumor feeder intraoperatively ruptured when the meningioma was resected. CASE PRESENTATION: Herein, we present a case of meningioma coexisting with contralateral UCA related to a tumor feeder. Immediately after the meningioma was resected, intraoperative acute brain swelling due to rupture of the contralateral aneurysm appeared. The swollen brain protruding into the epidural space was resected, following contralateral ruptured aneurysm was performed by endovascular surgery. Intensive neurological treatment was administered and the patient gradually recovered. CONCLUSION: This report highlights the possibility of intraoperative UCA rupture related to the tumor feeder when the meningioma is resected.

Intentional Bilateral Renal Artery Coverage During Ruptured Endovascular Paraanastomotic Pseudoaneurysm Repair.

The development of a paraanastomotic pseudoaneurysm is a serious complication after open prosthetic reconstruction of the aorta for occlusive or aneurysmal disease. Open repair of these lesions has previously been associated with high rates of morbidity and mortality. Endovascular repair may provide suitable treatment for proximal paraanastomotic aortic bypass graft pseudoaneurysms in patients who are poor candidates for open surgery. Bilateral renal artery coverage may be necessary to achieve adequate fixation and seal during life-threatening emergency cases of pseudoaneurysm rupture. Due to the infrequency of reported cases, the consequences of bilateral renal artery occlusion during these complex procedures are poorly understood. We present a case of a proximal paraanastomotic aortobifemoral bypass pseudoaneurysm rupture that was managed using endovascular repair with intentional coverage of both renal arteries. We also review the contemporary literature on endovascular management of paraanastomotic aneurysms and discuss the role of bilateral renal artery coverage in treating select patients with complex ruptured aortic pathology.

Intra-procedural complications, success rate, and need for retreatment of endovascular treatments in anterior communicating artery aneurysms: a systematic review and meta-analysis.

In recent years, intracranial aneurysms have been widely treated with endovascular methods. The anterior communicating artery (Acom) is the most common site of intracranial aneurysms. Despite its effectiveness, endovascular interventions can be associated with various intra-procedural and post-procedural complications. A systematic review of the literature was performed through PubMed, Embase, Scopus, and Web of Sciences databases up to March 18, 2022. The pooled rates of intra-procedural complications, mortality, procedure-related morbidities, the immediate and late aneurysm occlusion, and also the necessity for retreatment were calculated by applying random-effects models. A total of 41 articles with 4583 patients were included in the meta-analysis. The pooled rate of overall intra-procedural complications was 9.6% (95% CI: 7.7 to 11.8%). The initial rupture status and also type of EVT procedure did not affect the overall complication rate. The pooled rate of intra-procedural thrombosis, aneurysm rupture, coil prolapse, and early aneurysm rebleeding were 6.1% (95% CI: 4.5 to 8.2%); 4.2% (95% CI: 3.4 to 5.2%), 4.7% (95% CI: 3.2 to 6.7%), and 2.2% (95% CI: 1.5 to 3.2%), respectively. Our analysis showed that intra-procedural mortality occurred in 1.7% (95% CI: 1.1 to 2.5%) and procedure-related permanent morbidities in 3.3% (95% CI: 2.3 to 4.7%) of patients. Endovascular methods achieved complete and near to complete aneurysm occlusion (Raymond-Roy occlusion classification 1 and 2) in 89.2% (95% CI: 86.4 to 92.5%) of cases post-procedure, and 9.5% (95% CI: 7.3 to 12.4%) of patients needed retreatment due to recanalization in follow-ups. Endovascular treatment can serve as an acceptable method for Acom aneurysms. However, improved endovascular treatment equipment and new techniques provide more satisfactory outcomes for complicated cases.

A propensity score-matched study on the short-term outcome of ruptured blood blister-like aneurysm treated by microsurgery or endovascular surgery: a single-center study of 155 cases.

Treating blood blister-like aneurysms (BBA) is a major neurosurgical challenge. Whether endovascular repair serves as a better strategy than microsurgery remains controversial. We aim to perform a propensity score-matched (PSM) retrospective study to analyze the short-term outcome in BBA patients who received microsurgery and endovascular treatment. One hundred fifty-five eligible patients with internal carotid artery BBA were retrospectively collected with demographic and angiographic baseline in a single center. Three-month outcome and adverse events were set as outcome endpoints. PSM was used to match the microsurgery and endovascular group. Matching effect was evaluated by distribution variation analysis and love plot. The outcome of neurosurgery and endovascular treatment was then compared before and after PSM. Better WFNS levels (p = .017) and modified Fisher grade (p = .027) were noted in endovascular group before matching. Other baseline including angiographic features were comparable between two groups. Before matching, the 3-month outcome of endovascular repair surgery was more favorable than microsurgery (p < .0001). The occurrence of adverse events was also higher in the microsurgery group (p = .0079). In PSM-adjusted groups, the superior outcome effect of endovascular treatment still existed but with a reduced significance (p = .004). Similar trend was also observed in the adverse event rate (p = .038). Fatality rate was comparable between two adjusted groups regardless of PSM adjustment. Endovascular surgery of BBAs exhibits overall more favorable short-term outcome regardless of PSM matching. Microsurgery does not cause a higher fatality rate, hence it could be considered a salvage plan for those high-grade BBA patients.

The prognosis and treatment effectiveness of de novo aneurysm formation after radiation therapy for brain tumor.

Radiation therapy is a well-established, minimally invasive method of treating brain tumors. In recent years, the number of post-radiotherapy patients has increased, and delayed side effects are evident. De novo aneurysm formation after radiation often manifests as fatal subarachnoid hemorrhage (SAH), resulting in severe clinical outcomes. Nevertheless, the prognosis and therapeutic efficacy of radiation-induced aneurysms (RIAs) remain unclear. Using the PubMed database from 1980 to 2021, we screened 45 articles (53 individual cases) on RIAs; approximately 70% of RIAs were diagnosed after rupture. Of 38 ruptured RIAs, 12 (31.6%) had modified Rankin scale (mRS) 5-6. On the other hand, all unruptured RIAs (15 cases) recovered without neurological deficits (p = 0.012). Ten of the 39 ruptured RIAs were treated surgically, and 22 were treated endovascularly. There was no significant difference in mRS between treatment modalities (p = 0.393), but conservative therapy was significantly related to unfavorable outcomes (p = 0.025). To improve clinical outcomes, RIAs need to be diagnosed before rupture. Surgeons should be aware of de novo aneurysm formation in patients long after radiation therapy.

Pipeline flow diversion with adjunctive coil embolization for internal carotid artery aneurysms following an intradural component: results in 46 consecutive aneurysms from a Japanese single-center experience.

In the treatment of an intracranial aneurysm with the flow diverter, the combined use of coil embolization can help promote subsequent progressive thrombosis within the aneurysm sac and reduce the risk of delayed aneurysm rupture. This study retrospectively reviewed outcomes of patients who had undergone the Pipeline Embolization Device (PED) with adjunctive coil embolization (PED/coil) at a single center to determine its safety and efficiency. Patients with internal carotid artery aneurysms following an intradural component were selected for PED/coil between 2015 and 2020. All patients were premedicated with dual antiplatelet therapy of aspirin plus clopidogrel or prasugrel. A minimal number of PEDs were deployed, with coils inserted using a stent-jail technique, avoiding dense packing. A total of 46 aneurysms (43 patients; median dome size, 11.6 mm; median neck width, 6.3 mm) were treated with PED/coil. The median volume embolization ratio was 14.8%. The degree of angiographic filling at the 6-month and latest angiography showed complete occlusion in 60.5% (26/43) and 70.5% (31/44), respectively. Small (< 10 mm) aneurysms achieved a higher complete occlusion rate in the early period; a lower cumulative incidence of aneurysm occlusion was observed in large and giant (≥ 10 mm) aneurysms (P = .024). The median clinical follow-up was 22 months, and no aneurysm ruptures occurred. Favorable clinical outcomes were achieved, with permanent neurological morbidity of 4.7% and no mortality. PED/coil demonstrated a high angiographic occlusion rate at an early stage. Loosely packed coils are sufficient to obliterate aneurysms effectively.

Initial experience in the microsurgical treatment of ruptured brain aneurysms in the endovascular era: characteristics and safety of the learning curve in the first 300 consecutively treated patients.

PURPOSE: Currently, there is an increasing tendency to refer only complex aneurysms for microsurgery. The formation of new neurosurgeons dedicated to open vascular neurosurgery becomes challenging in a situation in which complex aneurysms must be dealt with early in the career, raising questions about the safety of the learning curve. METHODS: We analyzed the characteristics and surgical results of the first 300 consecutively treated patients after subarachnoid hemorrhage by a single neurosurgeon. The incidence of surgical complications and clinical outcomes during the learning curve were analyzed, looking for critical periods regarding patient safety. Microsurgical operative times were also studied. RESULTS: A high frequency of wide-necked aneurysms was observed (70.3%), and, as a result, large (> 10 mm), MCA and paraclinoid aneurysms were overrepresented. A statistically significant correlation between surgical experience and clinical outcomes was observed, with progressive surgical experience resulting in a lower incidence of unfavorable outcomes. We also observed a higher frequency of major surgical complications, unfavorable clinical outcomes, and lower complete occlusion rates among the first 40 patients. Microsurgical operative times progressively and significantly decreased during the learning curve. CONCLUSIONS: We observed a high prevalence of wide-necked aneurysms. Young neurosurgeons must be trained and prepared to deal with these aneurysms early in their careers. Although we observed a decrease in unfavorable results with cumulative surgical experience, the first 40 cases were associated with higher rates of major surgical complications, worse clinical outcomes, and lower complete occlusion rates, indicating that this period may be more critical to patient safety.