Subtemporal Approach for the Treatment of Ruptured and Unruptured Distal Basilar Artery Aneurysms: Is There a Contemporary Use?

BACKGROUND AND OBJECTIVES: Distal basilar artery aneurysms (DBAs) are high-risk lesions for which endovascular treatment is preferred because of their deep location, yet indications for open clipping nonetheless remain. The subtemporal approach allows for early proximal control and direct visualization of critical posterior perforating arteries, especially for posterior-projecting aneurysms. Our objective was to describe our clinical experience with the subtemporal approach for clipping DBAs in the evolving endovascular era. METHODS: This was a retrospective, single-institution case series of patients with DBAs treated with microsurgery over a 21-year period (2002-2023). Demographic, clinical, and surgical data were collected for analysis. RESULTS: Twenty-seven patients underwent clipping of 11 ruptured and 16 unruptured DBAs with a subtemporal approach (24 female; mean age 53 years). Ten patients had expanded craniotomies for treatment of additional aneurysms. The aneurysm occlusion rate was 100%. Good neurological outcomes as defined by the modified Rankin Scale score ≤2 and Glasgow Outcome Scale score ≥4 were achieved in 21/27 patients (78%). Two patients died before hospital discharge, one from vasospasm-induced strokes and another from an intraoperative myocardial infarction. CONCLUSION: These results demonstrate that microsurgical clip ligation of DBAs using the subtemporal approach remains a viable option for complex lesions not amenable to endovascular management.

Management of Symptomatic Hemorrhage From a Developmental Venous Anomaly.

Developmental venous anomalies (DVAs) are clinically benign, low-flow vascular malformations that classically hemorrhage only when associated with a cerebral cavernous malformation. It is very rare for an isolated DVA to hemorrhage. Resection of the DVA is generally contraindicated because of the high risk of venous infarct. We present the case of a large symptomatic hemorrhage stemming from an isolated DVA. The hematoma was evacuated and the hemorrhagic portion of the DVA was resected. This case demonstrates that in rare circumstances, careful resection can successfully treat hemorrhagic DVAs.

Frailty as a predictor of poor outcomes in patients with chronic subdural hematoma (cSDH): A systematic review of literature.

Objective: In recent years, frailty has been reported to be an important predictive factor associated with worse outcomes in neurosurgical patients. The purpose of the present systematic review was to analyze the impact of frailty on outcomes of chronic subdural hematoma (cSDH) patients. Methods: We performed a systematic review of literature using the PubMed, Cochrane library, Wiley online library, and Web of Science databases following PRISMA guidelines of studies evaluating the effect of frailty on outcomes of cSDH published until January 31, 2023. Results: A comprehensive literature search of databases yielded a total of 471 studies. Six studies with 4085 patients were included in our final qualitative systematic review. We found that frailty was associated with inferior outcomes (including mortality, complications, recurrence, and discharge disposition) in cSDH patients. Despite varying frailty scales/indices used across studies, negative outcomes occurred more frequently in patients that were frail than those who were not. Conclusions: While the small number of available studies, and heterogenous methodology and reporting parameters precluded us from conducting a pooled analysis, the results of the present systematic review identify frailty as a robust predictor of worse outcomes in cSDH patients. Future studies with a larger sample size and consistent frailty scales/indices are warranted to strengthen the available evidence. The results of this work suggest a strong case for using frailty as a pre-operative risk stratification measure in cSDH patients.

Preservation of cranial nerve function in large and giant trigeminal schwannoma resection: a case series.

BACKGROUND: Trigeminal schwannomas (TSs) are intracranial tumors that can cause significant brainstem compression. TS resection can be challenging because of the risk of new neurologic and cranial nerve deficits, especially with large (≥ 3 cm) or giant (≥ 4 cm) TSs. As prior surgical series include TSs of all sizes, we herein present our clinical experience treating large and giant TSs via microsurgical resection. METHODS: This was a retrospective, single-surgeon case series of adult patients with large or giant TSs treated with microsurgery in 2012-2023. RESULTS: Seven patients underwent microsurgical resection for TSs (1 large, 6 giant; 4 males; mean age 39 ± 14 years). Tumors were classified as type M (middle fossa in the interdural space; 1 case, 14%), type ME (middle fossa with extracranial extension; 3 cases, 43%), type MP (middle and posterior fossae; 2 cases, 29%), or type MPE (middle/posterior fossae and extracranial space; 1 case, 14%). Six patients were treated with a frontotemporal approach (combined with transmastoid craniotomy in the same sitting in one patient and a delayed transmaxillary approach in another), and one patient was treated using an orbitofrontotemporal approach. Gross total resection was achieved in 5 cases (2 near-total resections). Five patients had preoperative facial numbness, and 6 had immediate postoperative facial numbness, including two with worsened or new symptoms. Two patients (28%) demonstrated new non-trigeminal cranial nerve deficits over mean follow-up of 22 months. Overall, 80% of patients with preoperative facial numbness and 83% with facial numbness at any point experienced improvement or resolution during their postoperative course. All patients with preoperative or new postoperative non-trigeminal tumor-related cranial nerve deficits (4/4) experienced improvement or resolution on follow-up. One patient experienced tumor recurrence that has been managed conservatively. CONCLUSIONS: Microsurgical resection of large or giant TSs can be performed with low morbidity and excellent long-term cranial nerve function.

Multicenter Registry of Adenomas of the Pituitary and Related Disorders: Initial Description of Cushing Disease Cohort, Surgical Outcomes, and Surgeon Characteristics.

BACKGROUND AND OBJECTIVES: To address the lack of a multicenter pituitary surgery research consortium in the United States, we established the Registry of Adenomas of the Pituitary and Related Disorders (RAPID). The goals of RAPID are to examine surgical outcomes, improve patient care, disseminate best practices, and facilitate multicenter surgery research at scale. Our initial focus is Cushing disease (CD). This study aims to describe the current RAPID patient cohort, explore surgical outcomes, and lay the foundation for future studies addressing the limitations of previous studies. METHODS: Prospectively and retrospectively obtained data from participating sites were aggregated using a cloud-based registry and analyzed retrospectively. Standard preoperative variables and outcome measures included length of stay, unplanned readmission, and remission. RESULTS: By July 2023, 528 patients with CD had been treated by 26 neurosurgeons with varying levels of experience at 9 academic pituitary centers. No surgeon treated more than 81 of 528 (15.3%) patients. The mean ± SD patient age was 43.8 ± 13.9 years, and most patients were female (82.2%, 433/527). The mean tumor diameter was 0.8 ± 2.7 cm. Most patients (76.6%, 354/462) had no prior treatment. The most common pathology was corticotroph tumor (76.8%, 381/496). The mean length of stay was 3.8 ± 2.5 days. The most common discharge destination was home (97.2%, 513/528). Two patients (0.4%, 2/528) died perioperatively. A total of 57 patients (11.0%, 57/519) required an unplanned hospital readmission within 90 days of surgery. The median actuarial disease-free survival after index surgery was 8.5 years. CONCLUSION: This study examined an evolving multicenter collaboration on patient outcomes after surgery for CD. Our results provide novel insights on surgical outcomes not possible in prior single-center studies or with national administrative data sets. This collaboration will power future studies to better advance the standard of care for patients with CD.

Transmaxillary approach for resection of maxillary division trigeminal schwannoma at foramen rotundum.

BACKGROUND: The foramen rotundum and anterior cavernous sinus have traditionally been accessed by transcranial approaches that are limited by the high density of critical neurovascular structures. The transmaxillary approach provides an entirely extradural route to the foramen rotundum and anterior cavernous sinus. METHOD: This patient with neurofibromatosis and facial pain with trigeminal schwannoma at the foramen rotundum was successfully treated by transmaxillary resection of the tumor. This approach allowed for a direct extradural access to the pathology, with bony decompression and tumor resection, avoiding transcranial routes. CONCLUSION: The transmaxillary approach provides a safe and entirely extradural corridor to access smaller localized skull base lesions at and surrounding the cavernous sinus.

The risk analysis index demonstrates superior discriminative ability in predicting extended length of stay in pituitary adenoma resection patients when compared to the 5-point modified frailty index.

Objective: To compare the predictive abilities of two frailty indices on post-operative morbidity and mortality in patients undergoing pituitary adenoma resection. Methods: The National Surgical Quality Improvement Program (NSQIP) database was used to retrospectively collect data for patients undergoing pituitary adenoma resection between 2015-2019. To compare the predictive abilities of two of the most common frailty indices, the 5-point modified frailty index (mFI-5) and the risk analysis index (RAI), receiver operating curve analysis (ROC) and area under the curve (AUC)/Cstatistic were used. Results: In our cohort of 1,454 patients, the RAI demonstrated superior discriminative ability to the mFI-5 in predicting extended length of stay (C-statistic 0.59, 95% CI 0.56-0.62 vs. C-statistic 0.51, 95% CI: 0.48-0.54, p = 0.0002). The RAI only descriptively appeared superior to mFI-5 in determining mortality (C-statistic 0.89, 95% CI 0.74-0.99 vs. Cstatistic 0.63, 95% CI 0.61-0.66, p=0.11), and NHD (C-statistic 0.68, 95% CI 0.60-0.76 vs. C-statistic 0.60, 95% CI: 0.57-0.62, p=0.15). Conclusions: Pituitary adenomas account for one of the most common brain tumors in the general population, with resection being the preferred treatment for patients with most hormone producing tumors or those causing compressive symptoms. Although pituitary adenoma resection is generally safe, patients who experience post-operative complications frequently share similar pre-operative characteristics and comorbidities. Therefore, appropriate pre-operative risk stratification is imperative for adequate patient counseling and informed consent in these patients. Here we present the first known report showing the superior discriminatory ability of the RAI in predicting eLOS when compared to the mFI-5.

The role of surgical management for prolactin-secreting tumors in the era of dopaminergic agonists: An international multicenter report.

OBJECTIVE: First-line prolactin-secreting tumor (PST) management typically involves treatment with dopamine agonists and the role of surgery remains to be further explored. We examined the international experience of 12 neurosurgical centers to assess the patient characteristics, safety profile, and effectiveness of surgery for PST management. METHODS: Patients surgically treated for PST from January 2017 through December 2020 were evaluated for surgical characteristics, outcomes, and safety. RESULTS: Among 272 patients identified (65.1% female), the mean age was 38.0 ± 14.3 years. Overall, 54.4% of PST were macroadenomas. Minor complications were seen in 39.3% of patients and major complications were in 4.4%. The most common major complications were epistaxis and worsened vision. Most minor complications involved electrolyte/sodium dysregulation. At 3-6 months, local control on imaging was achieved in 94.8% of cases and residual/recurrent tumor was seen in 19.3%. Reoperations were required for 2.9% of cases. On multivariate analysis, previous surgery was significantly predictive of intraoperative complications (6.14 OR, p < 0.01) and major complications (14.12 OR, p < 0.01). Previous pharmacotherapy (0.27 OR, p = 0.02) and cavernous sinus invasion (0.19 OR, p = 0.03) were significantly protective against early endocrinological cure. Knosp classification was highly predictive of residual tumor or PST recurrence on 6-month follow-up imaging (4.60 OR, p < 0.01). There was noted institutional variation in clinical factors and outcomes. CONCLUSION: Our results evaluate a modern, multicenter, global series of PST. These data can serve as a benchmark to compare with DA therapy and other surgical series. Further study and longer term outcomes could provide insight into how patients benefit from surgical treatment.

Clinical Characteristics and Surgical Outcomes of 2542 Patients with Spinal Schwannomas: A Systematic Review and Meta-Analysis.

OBJECTIVE: This study was conducted to systematically analyze the data on the clinical features, surgical treatment, and outcomes of spinal schwannomas. METHODS: We conducted a systematic review and meta-analysis under the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search of bibliographic databases from January 1, 2001, to May 31, 2021, yielded 4489 studies. Twenty-six articles were included in our final qualitative systematic review and quantitative meta-analysis. RESULTS: Analysis of 2542 adult patients' data from 26 included studies showed that 53.5% were male, and the mean age ranged from 35.8 to 57.1 years. The most common tumor location was the cervical spine (34.2%), followed by the thoracic spine (26.2%) and the lumbar spine (18.5%). Symptom severity was the most common indicator for surgical treatment, with the most common symptoms being segmental back pain, sensory/motor deficits, and urinary dysfunction. Among all patients analyzed, 93.8% were treated with gross total resection, which was associated with better prognosis and less chance of recurrence than subtotal resection. The posterior approach was the most common (87.4% of patients). The average operative time was 4.53 hours (95% confidence interval [CI], 3.18-6.48); the average intraoperative blood loss was 451.88 mL (95% CI, 169.60-1203.95). The pooled follow-up duration was 40.6 months (95% CI, 31.04-53.07). The schwannoma recurrence rate was 5.3%. Complications were particularly low and included cerebrospinal fluid leakage, wound infection, and the sensory-motor deficits. Most of the patients experienced complete recovery or significant improvement of preoperative neurological deficits and pain symptoms. CONCLUSIONS: Our analysis suggests that segmental back pain, sensory/motor deficits, and urinary dysfunction are the most common symptoms of spinal schwannomas. Surgical resection is the treatment of choice with overall good reported outcomes and particularly low complication rates. gross total resection offers the best prognosis with the slightest chance of tumor recurrence and minimal risk of complications.

Half-and-Half Approach for Multiple Aneurysms at the Superior Cerebellar and Middle Cerebral Arteries.

Aneurysms at the superior cerebellar artery (SCA) are commonly treated endovascularly because of their location around the basilar artery,1,2 but they are not intimately related with thalamoperforators. Therefore in younger patients, those with wide-necked aneurysms, or those with multiple ipsilateral aneurysms, surgery remains a treatment option.3 We present a 52-year-old woman with dizziness in whom multiple, unruptured intracranial aneurysms were identified. Imaging demonstrated a 9-mm right-sided SCA aneurysm and 5-mm right and mirror 3-mm left M1 segment middle cerebral artery aneurysms. The patient gave consent to undergo surgery after counseling regarding her treatment options. A pterional and temporal craniotomy was performed to allow for half-and-half subtemporal and transsylvian approaches (Video 1). Here, we discuss the nuances of the approach related to the anatomy of SCA aneurysms. The challenges of the surgery can be mediated with techniques including division of the tentorium for enhanced exposure and early proximal control with temporary clinping or the use of adenosine (cardiac arrest). Our patient remained neurologically stable postoperatively and in 1-year follow-up. SCA aneurysms are easily visualized by the subtemporal and transsylvian approaches; they are frequently located adjacent to the posterior cerebral artery above and the SCA below. A modified transcavernous approach using the orbitozygomatic craniotomy has been described for access to basilar tip aneurysms.4 While comparable, this case demonstrates the efficient workflow to clip multiple aneurysms using a single, combined approach. In patients with multiple aneurysms presenting ipsilaterally or with comorbid conditions that complicate endovascular embolization, surgery should be considered as a definitive and safe treatment strategy. The patient consented to publication.

In-out-in technique for petrosal sinus dural arteriovenous fistula obliteration: How I Do It.

BACKGROUND: Dural arteriovenous fistulas (dAVFs) at the superior petrosal sinus are a rare but important subtype that pose a high risk of mortality and morbidity. Treatment for these lesions can be challenging with stand-alone endovascular methods. METHODS: We describe our "in-out-in" technique for disconnecting dAVFs at the superior petrosal sinus, which includes definitive sacrifice of the superior petrosal sinus and the transverse sigmoid sinus, if involved. This method achieves complete fistula obliteration and minimizes recurrence risk with new arterial feeders. CONCLUSIONS: The in-out-in technique is a safe and effective approach for the treatment of dAVFs involving the superior petrosal sinus.

Crooke Cell Adenoma Confers Poorer Endocrinological Outcomes Compared with Corticotroph Adenoma: Results of a Multicenter, International Analysis.

BACKGROUND: Crooke cell adenomas (CCAs) are a rare, aggressive subset of secretory pituitary corticotroph adenomas (sCTAs) found in 5%-10% of patients with Cushing disease. Multiple studies support worse outcomes in CCAs but are limited by small sample size and single-institution databases. We compared outcomes in CCA and sCTA using a multicenter, international retrospective database of high-volume skull base centers. METHODS: Patients surgically treated for pituitary adenoma from January 2017 through December 2020 were included. RESULTS: Among 2826 patients from 12 international centers, 20 patients with CCA and 480 patients with sCTA were identified. No difference in baseline demographics, tumor characteristics, or postoperative complications was seen. Microsurgical approaches (60% CCA vs. 62.3% sCTA) were most common. Gross total resection was higher in CCA patients (100% vs. 83%, P = 0.05). Among patients with gross total resection according to intraoperative findings, fewer CCA patients had postoperative hormone normalization of pituitary function (50% vs. 77.8%, P < 0.01) and remission of hypersecretion by 3-6 months (75% vs. 84.3%, P < 0.01). This was the case despite CCA having better local control rates (100% vs. 96%, P < 0.01) and fewer patients with remnant on magnetic resonance imaging (0% vs. 7.2%, P < 0.01). A systematic literature review of 35 studies reporting on various treatment strategies reiterated the high rate of residual tumor, persistent hypercortisolism, and tumor-related mortality in CCA patients. CONCLUSIONS: This modern, multicenter series of patients with CCA reflects their poor prognosis and reduced postsurgical hormonal normalization. Further work is necessary to better understand the pathophysiology of CCA to devise more targeted treatment approaches.

Results of Surgical Treatment of Aneurysmal Subarachnoid Hemorrhage in a Single Institution Over 12 Years.

OBJECTIVE: For patients with aneurysmal subarachnoid hemorrhage (aSAH) in whom endovascular treatment is not the optimal treatment strategy, microsurgical clipping remains a viable option. We examined changes in morbidity and outcome over time in patients treated surgically and in relation to surgeon volume and experience. METHODS: All patients who underwent microsurgery for aSAH from 2007 to 2019 at our institution were included. We compared technical complication rates and surgical outcomes between experienced (≥50 independent cases) and inexperienced (<50 independent cases) surgeons and between high-volume (≥20 cases/year) and low-volume (<20 cases/year) surgeons. RESULTS: Most of the 1,003 aneurysms (970 patients, median age 56 years) were in the middle cerebral (41.4%), anterior communicating (27.6%), and posterior communicating (17.5%) arteries; 46.5% were <7 mm. The technical complication rate was 7%, resulting in postoperative infarct in 4.9% of patients. Nineteen patients (2%) died within 30 days of admission. There were no significant changes in rates of technical complication, postoperative infarct, or mortality over the study period. There were no differences in postoperative infarction and technical complication rates between experienced and inexperienced surgeons (P = 0.28 and P = 0.05, respectively), but there were differences when comparing high-volume and low-volume surgeons (P = 0.03 and P < 0.001, respectively). The independent predictors of postoperative infarctions were aneurysm size (P = 0.001), intraoperative large-vessel injury (P < 0.001), and low surgeon volume (P = 0.03). CONCLUSIONS: We present real-world data on surgical morbidity and outcomes after aSAH. We demonstrated a relationship between surgeon volume and outcome for surgical treatment of aSAH, which supports the benefit of subspecialization in cerebrovascular surgery.

Long-term functional outcomes and complications of microsurgical resection of brainstem cavernous malformations: a systematic review and meta-analysis.

Brainstem cavernous malformations (CMs) encompass up to 20% of all intracranial CMs and are considered more aggressive than cerebral CMs because of their high annual bleeding rates. Microsurgical resection remains the primary treatment modality for CMs, but long-term functional outcomes and complications are heterogenous in the literature. The authors performed a systematic review on brainstem CMs in 4 databases: PubMed, EMBASE, Cochrane library, and Google Scholar. We included studies that reported on the long-term functional outcomes and complications of brainstem CMs microsurgical resection. A meta-analysis was performed and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The search yielded 4781 results, of which 19 studies met our inclusion criteria. Microsurgery was performed on 940 patients (mean age 35 years, 46.9% females). Most of the brainstem CMs were located in the pons (n = 475). The pooled proportions of improved, stable, and worsened functional outcomes after microsurgical resection of brainstem CMs were 56.7% (95% CI 48.4-64.6), 28.6% (95% CI 22.4-35.7), and 12.6% (95% CI 9.6-16.2), respectively. CMs located in the medulla were significantly (p = 0.003) associated with a higher proportion of improved outcome compared with those in the pons and midbrain. Complete resection was achieved in 93.3% (95% CI 89.8-95.7). The immediate postoperative complication rate was 37.2% (95% CI 29.3-45.9), with new-onset cranial nerve deficit being the most common complication. The permanent morbidity rate was 17.3% (95% CI 10.5-27.1), with a low mortality rate of 1% from the compiled study population during a mean follow-up of 58 months. Our analysis indicates that microsurgical resection of brainstem CMs can result in favorable long-term functional outcomes with transient complications in the majority of patients. Complete microsurgical resection of the CM is associated with a lower incidence of CM hemorrhage and the morbidity related to it.

Defining benchmark outcomes for transsphenoidal surgery of pituitary adenomas: a multicenter analysis.

IMPORTANCE: Benchmarks aid in improve outcomes for surgical procedures. However, best achievable results that have been validated internationally for transsphenoidal surgery (TS) are not available. OBJECTIVE: We aimed to establish standardized outcome benchmarks for TS of pituitary adenomas. DESIGN: A total of 2685 transsphenoidal tumor resections from 9 expert centers in 3 continents were analyzed. SETTING: Patients were risk stratified, and the median values of each center's outcomes were established. The benchmark was defined as the 75th percentile of all median values for a particular outcome. The postoperative benchmark outcomes included surgical factors, endocrinology-specific values, and neurology-specific values. RESULTS: Of 2685 patients, 1149 (42.8%) defined the low-risk benchmark cohort. Within these benchmark cases, 831 (72.3%) patients underwent microscopic TS, and 308 (26.8%) patients underwent endoscopic endonasal resection. Of all tumors, 799 (29.8%) cases invaded the cavernous sinus. The postoperative complication rate was 19.6% with mortality between 0.0% and 0.8%. Benchmark cutoffs were ≤2.9% for reoperation rate, ≤1.9% for cerebrospinal fluid leak requiring intervention, and ≤15.5% for transient diabetes insipidus. At 6 months, benchmark cutoffs were calculated as follows: readmission rate: ≤6.9%, new hypopituitarism ≤6.0%, and tumor remnant ≤19.2%. CONCLUSIONS: This analysis defines benchmark values for TS targeting morbidity and mortality and represents the best outcomes in the best patients in expert centers. These cutoffs can be used to assess different centers, patient populations, and novel surgical techniques. It should be noted that the benchmark values may influence each other and must be evaluated in their own context.

Combined and staged retrosigmoid, extended middle fossa, and endoscopic transnasal approach to a petroclival chondrosarcoma: how I do it.

BACKGROUND: Tumors of the petroclival region with multicompartment extension can be difficult to address with a single surgical approach. METHOD: We present the case of a patient with a large chondrosarcoma centered at the right petroclival fissure with extension into the cavernous sinus, the region beneath the cavernous sinus, cerebellopontine angle with deformation of the pons, and prevertebral space. A staged complete resection was performed using a stage 1 single-incision combined right retrosigmoid craniotomy and extended middle fossa craniotomy, followed by a stage 2 endoscopic transnasal approach. CONCLUSION: A combined approach to selected petroclival tumors can maximize safe resection.

Multiple approaches to a spheno-orbital and deep face meningioma: how I do it.

BACKGROUND: The integration of multiple approaches is sometimes needed for the safe resection of complex multicompartment skull base tumors. METHOD: We present the case of a spheno-orbital and deep face meningioma that required a staged resection strategy using transnasal, transoral, transfacial, and transcranial approaches for airway protection and maximal safe tumor removal. CONCLUSION: Limitations in individual skull base approaches for complex tumors can be anticipated and overcome by combining approaches.

Combined retrosigmoid and middle fossa approach for a small, superiorly located petroclival meningioma: how I do it.

BACKGROUND: Petroclival meningiomas pose significant surgical challenges because of their deep location and complex surrounding neurovasculature. The use of multiple surgical approaches can optimize safe tumor removal from multiple anatomic compartments. METHOD: We describe a patient with a growing superior petroclival meningioma centered at the posterior clinoid with extension into Meckel's cave that was successfully removed with a combined retrosigmoid and subtemporal middle fossa approach. This strategy avoided the need for anterior petrous bone drilling and tentorial splitting. CONCLUSION: A combined retrosigmoid and subtemporal middle fossa approach can provide safe access to tumors spanning the supra- and infratentorial compartments.

Complications of Endovascular and Open Aneurysm Surgery in the Era of Flow Diversion.

The techniques used for treatment of intracranial aneurysms have progressed dramatically over the decades. The introduction of modern endovascular techniques and the continued refinement of progressively less invasive neurosurgical approaches have contributed to steadily improving clinical outcomes. Moreover, innovations such as flow-diverting stents have achieved dramatic success and have gained rapid widespread adoption. Particularly in lesions for which the application of conventional treatment techniques is difficult, flow diversion technology has revolutionized aneurysm management. This review provides a discussion on the morbidity and mortality encountered in the treatment of intracranial aneurysms in the modern era. Common adverse events faced in the management of these lesions with open surgery and various endovascular techniques are highlighted.