Microsurgical clipping of ophthalmic artery aneurysms

J Neurosurg 129:1511–1521, 2018

While most paraclinoid aneurysms can be clipped with excellent results, new postoperative visual deficits are a concern. New technology, including flow diverters, has increased the popularity of endovascular therapy. However, endovascular treatment of paraclinoid aneurysms is not without procedural risks, is associated with higher rates of incomplete aneurysm occlusion and recurrence, and may not address optic nerve compression symptoms that surgical debulking can. The increasing endovascular management of paraclinoid aneurysms should be justified by comparisons to surgical benchmarks. The authors, therefore, undertook this study to define patient, visual, and aneurysm outcomes in the most common type of paraclinoid aneurysm: ophthalmic artery (OphA) aneurysms.

METHODS Results from microsurgical clipping of 208 OphA aneurysms in 198 patients were retrospectively reviewed. Patient demographics, aneurysm morphology (size, calcification, etc.), clinical characteristics, and patient outcomes were recorded and analyzed.

RESULTS Despite 20% of these aneurysms being large or giant in size, complete aneurysm occlusion was accomplished in 91% of 208 cases, with OphA patency preserved in 99.5%. The aneurysm recurrence rate was 3.1% and the retreatment rate was 0%. Good outcomes (modified Rankin Scale score 0–2) were observed in 96.2% of patients overall and in all 156 patients with unruptured aneurysms. New visual field defects (hemianopsia or quadrantanopsia) were observed in 8 patients (3.8%), decreased visual acuity in 5 (2.4%), and monocular blindness in 9 (4.3%). Vision improved in 9 (52.9%) of the 17 patients with preoperative visual deficits.

CONCLUSIONS The most important risk associated with clipping OphA aneurysms is a new visual deficit. Meticulous microsurgical technique is necessary during anterior clinoidectomy, aneurysm dissection, and clip application to optimize visual outcomes, and aggressive medical management postoperatively might potentially decrease the incidence of delayed visual deficits. As the results of endovascular therapy and specifically flow diverters become known, they warrant comparison with these surgical benchmarks to determine best practices.

External validation of cerebral aneurysm rupture probability model with data from two patient cohorts

Acta Neurochirurgica (2018) 160:2425–2434

For a treatment decision of unruptured cerebral aneurysms, physicians and patients need to weigh the risk of treatment against the risk of hemorrhagic stroke caused by aneurysm rupture. The aim of this study was to externally evaluate a recently developed statistical aneurysm rupture probability model, which could potentially support such treatment decisions.

Methods Segmented image data and patient information obtained from two patient cohorts including 203 patients with 249 aneurysms were used for patient-specific computational fluid dynamics simulations and subsequent evaluation of the statistical model in terms of accuracy, discrimination, and goodness of fit. The model’s performance was further compared to a similaritybased approach for rupture assessment by identifying aneurysms in the training cohort that were similar in terms of hemodynamics and shape compared to a given aneurysm from the external cohorts.

Results When applied to the external data, the model achieved a good discrimination and goodness of fit (area under the receiver operating characteristic curve AUC = 0.82), which was only slightly reduced compared to the optimism-corrected AUC in the training population (AUC = 0.84). The accuracy metrics indicated a small decrease in accuracy compared to the training data (misclassification error of 0.24 vs. 0.21). The model’s prediction accuracy was improved when combined with the similarity approach (misclassification error of 0.14).

Conclusions The model’s performance measures indicated a good generalizability for data acquired at different clinical institutions. Combining the model-based and similarity-based approach could further improve the assessment and interpretation of new cases, demonstrating its potential use for clinical risk assessment.

Surgical Clipping of Previously Ruptured, Coiled Aneurysms: Outcome Assessment in 53 Patients

World Neurosurg. (2018) 120:e203-e211

Occasionally, previously coiled aneurysms will require secondary treatment with surgical clipping, representing a more complicated aneurysm to treat than the naïve aneurysm. Patients who initially presented with a ruptured aneurysm may pose an even riskier group to treat than those with unruptured previously coiled aneurysms, given their potentially higher risk for rerupture. The objective of this study was to assess the clinical outcomes of patients who undergo microsurgical clipping of ruptured previously coiled cerebral aneurysms. In addition, we present a thorough review of the literature.

METHODS: A total of 53 patients from a single institution who initially presented with a subarachnoid hemorrhage and underwent surgical clipping of a previously coiled aneurysm between December 1997 and December 2014 were studied. Clinical features, hospital course, and preoperative and most recent functional status (Glasgow Outcome Scale score) were reviewed retrospectively.

RESULTS: The mean time interval from coiling to clipping was 2.6 years, and mean follow-up was 5.5 years (range, 0.1e14.7 years). Five patients (9.8%) presented with rebleed prior to clipping. Most patients (79.3%, 42/53) experienced good neurologic outcomes. Most showed no change (81%, 43/53) or improvement (13%, 7/53) in functional status after microsurgical clipping. One patient (2%) deteriorated clinically, and there were 2 mortalities (4%).

CONCLUSIONS: Microsurgical clipping of previously ruptured, coiled aneurysms is a promising treatment method with favorable clinical outcomes

Reliable Identification of Benign Clinical Course in Aneurysmal Subarachnoid Hemorrhage

Neurosurgery 83:948–956, 2018

A reliable method to specifically identify low vasospasm risk in aneurysmal subarachnoid hemorrhage (aSAH) patients has not been previously proposed.

OBJECTIVE: To develop a clinical algorithm using admission aSAH clinical severity and subarachnoid blood distribution to identify patients at low risk of clinical vasospasm.

METHODS: Clinical severities, admission noncontrasted head computerized tomography (CT) scan, and incidences of vasospasm among 291 aSAH patients treated at our institutionwere evaluated. Admission head CTswere assessed for distributions of cisternal and ventricular blood. Patients with the following 4 criteria experienced considerably lower risk of vasospasm: (1) Hunt Hess grade 1 to 2, (2) Lack of thick subarachnoid blood filling 2 adjacent cisterns, (3) Lack of thick interhemispheric blood, and (4) Lack of biventricular intraventricular hemorrhage.

RESULTS: One hundred thirty-three patients (45.7%) developed cerebral vasospasm. Hunt Hess grade greater than 2 (odds ratio [OR] 4.52, 95% confidence interval [CI] 2.74-7.46), adjacent cistern blood (OR 4.1, 95% CI 2.51-6.7), interhemispheric thick blood (OR 5.72, 95% CI 3.41-9.59), and biventricular intraventricular hemorrhage (OR 1.92, 95% CI 1.19-3.02) were significant risk factors. Application of our algorithm yielded a sensitivity of 29%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 54.5%, which was superior compared to metrics from current institutional practice criteria. Inter-rater agreement was substantial at mean kappa = 0.75.

CONCLUSION: Application of our novel clinical algorithm produced successful identification of aSAH patients who experience zero risk of clinical vasospasm. Our algorithm is simple to apply with high reliability and is superior to currently available clinical and radiographic metrics.

Impact of aneurysm shape on morbidity after clipping of unruptured intracranial aneurysms

Acta Neurochirurgica (2018) 160:2169–2176

Complex aneurysm shape is a predominant risk factor for aneurysm rupture but its impact on clinical outcome after clipping remains unclear. The objective of the present study was to compare complications and morbidity after clipping of unruptured single-sac aneurysms (SSAs) and aneurysms with multiple sacs (MSAs).

Methods A retrospective, single-center study was conducted for patients that were treated between 2010 and 2018. We analyzed
surgical parameters, treatment-related complications, and morbidity, defined as any increase in the modified Rankin scale at 3-
month follow-up.

Results We identified 101 patients (mean age: 52.9 ± 10.5 years) that underwent clipping for 57 SSAs and 44 MSAs. The two
groups were comparable regarding aneurysm size and neck width. Clipping of MSAs was associated with a longer operation time
(p = 0.008) and increased use of intraoperative indocyanine green (p = 0.016) than SSAs. Complications occurred more often in
the MSA group (29.5%) than in the SSA group (14.0%; p = 0.057). Morbidity was significantly higher in the MSA group
(20.5%) than in the SSA group (3.5%, p = 0.009). In the univariate analysis, the odds of morbidity were 7.1 times greater for
MSAs than for SSAs (95% CI 1.4–34.7).

Conclusions Morbidity after microsurgical clipping is significantly increased in MSAs as compared to SSAs. This may be
attributed to a more difficult clip placement with stronger manipulation of the aneurysm dome and the surrounding brain tissue.

 

Coiling Versus Microsurgical Clipping in the Treatment of Unruptured Middle Cerebral Artery Aneurysms: A Meta-Analysis

Neurosurgery 83:879–889, 2018

Open microsurgical clipping of unruptured intracranial aneurysms has long been the gold standard, yet advancements in endovascular coiling techniques have begun to challenge the status quo. OBJECTIVE: To compare endovascular coiling with microsurgical clipping among adults with unruptured middle cerebral artery aneurysms (MCAA) by conducting a meta-analysis.

METHODS: A systematic search was conducted from January 2011 to October 2015 to update a previous meta-analysis. All studies that reported unruptured MCAA in adults treated by microsurgical clipping or endovascular coiling were included and cumulatively analyzed.

RESULTS: Thirty-seven studies including 3352 patients were included. Using the randomeffects model, pooled analysis of 11 studies of microsurgical clipping (626 aneurysms) revealed complete aneurysmal obliteration in 94.2% of cases (95% confidence interval [CI] 87.6%-97.4%). The analysis of 18 studies of endovascular coiling (759 aneurysms) revealed complete obliteration in 53.2% of cases (95% CI: 45.0%-61.1%). Among clipping studies, 22 assessed neurological outcomes (2404 aneurysms), with favorable outcomes in 97.9% (95% CI: 96.8%-98.6%). Among coiling studies, 22 examined neurological outcomes (826 aneurysms), with favorable outcomes in 95.1% (95% CI: 93.1%-96.5%). Results using the fixed-effect models were not materially different.

CONCLUSION: This updated meta-analysis demonstrates that surgical clipping for unruptured MCAA remains highly safe and efficacious. Endovascular treatment for unruptured MCAAs continues to improve in efficacy and safety; yet, it results in lower rates of occlusion.

 

Double-barrel STA to proximal MCA bypass and proximal parent artery occlusion for a fusiform superior clinoidal ICA aneurysm

Acta Neurochirurgica (2018) 160:1939–1943

Blood flow replacement and parent artery occlusion are alternative treatments of complex fusiform superior clinoidal ICA aneurysms. While double-barrel STA to proximal MCA bypass is a conventional approach among these reported bypass algorithms, its technical details remain underexplored.

Method We have applied the double-barrel STA to proximal MCA bypass and parent artery occlusion to treat a 45-year-old female patient with a right fusiform superior clinoidal ICA aneurysm. The technical nuances of this approach are reported.

Conclusion We show that double-barrel STA to proximal MCA bypass and proximal parent artery occlusion can be alternative treatments of complex fusiform superior clinoidal ICA aneurysms.

Double-barrel STA to proximal MCA bypass and proximal parent artery occlusion for a fusiform superior clinoidal ICA aneurysm

Acta Neurochirurgica (2018) 160:1939–1943

Blood flow replacement and parent artery occlusion are alternative treatments of complex fusiform superior clinoidal ICA aneurysms. While double-barrel STA to proximal MCA bypass is a conventional approach among these reported bypass algorithms, its technical details remain underexplored.

Method We have applied the double-barrel STA to proximal MCA bypass and parent artery occlusion to treat a 45-year-old female patient with a right fusiform superior clinoidal ICA aneurysm. The technical nuances of this approach are reported.

Conclusion We show that double-barrel STA to proximal MCA bypass and proximal parent artery occlusion can be alternative treatments of complex fusiform superior clinoidal ICA aneurysms.

The eyebrow approach for anterior circle of Willis aneurysms

Acta Neurochirurgica (2018) 160:1749–1753

The eyebrow approach is a keyhole technique that gives a wide access to the anterior circle of Willis.

Methods A 4-cm linear incision is placed in the upper limit of the eyebrow and a small supraorbital bone flap is raised. A wide arachnoid dissection is essential to maximize the working space. One or multiple aneurysms may be treated by the same approach.

Conclusions The eyebrow approach is a safe technique for selected aneurysms of the anterior circle of Willis

Unruptured intracranial aneurysms in patients over 80 years

Acta Neurochirurgica (2018) 160:1773–1777

Patients over the age of 80 years when diagnosed with an unruptured intracranial aneurysm (UIA) pose unique decisionmaking challenges due to shortened life-expectancy and increased risk of treatment. Thus, we investigated the risk of rupture and survival of a consecutive series of patients who were diagnosed with an UIA after the age of 80 years.

Methods Data of consecutive patients with an UIA were reviewed, and patients were included in our study if they were first evaluated for a UIA by the senior author during their ninth decade of life. Outcomes were aneurysm rupture and overall survival after diagnosis. Survival was estimated from a Kaplan-Meier survival curve. Incidence of risk factors was compared to a population of patients less than 65 years who were seen by the senior author over the same time period.

Results Eighty-three patients who were over 80 years when diagnosed with a UIA were included in this study. In our population, there is a risk of rupture of 3.2% per patient-year. One-, three-, and five-year survival rates for our population were estimated to be 92, 64, and 35%, respectively. When compared to patients under 65 years diagnosed with a UIA, Bover 80^ patients had a significantly higher incidence of hypertension, and a significantly lower incidence of smoking history and familial aneurysm history.

Conclusions In our study population, UIAs greater than 7 mm carry a non-negligible risk of rupture of 3.2% per patient-year, and further studies investigating the risk-to-benefit ratio of treatment in this population are warranted.

Effect of body mass index on outcome after aneurysmal subarachnoid hemorrhage treated with clipping versus coiling

J Neurosurg 129:658–669, 2018

It has been suggested that increased body mass index (BMI) may confer a protective effect on patients who suffer from aneurysmal subarachnoid hemorrhage (aSAH). Whether the modality of aneurysm occlusion influences the effect of BMI on patient outcomes is not well understood. The authors aimed to compare the effect of BMI on outcomes for patients with aSAH treated with surgical clipping versus endovascular coiling.

METHODS The authors retrospectively reviewed the outcomes for patients admitted to their institution for the management of aSAH treated with either clipping or coiling. BMI at the time of admission was recorded and used to assign patients to a group according to low or high BMI. Cutoff values for BMI were determined by classification and regression tree analysis. Predictors of poor functional outcome (defined as modified Rankin Scale score > 2 measured ≥ 90 days after the ictus) and posttreatment cerebral hypodensities detected during admission were then determined separately for patients treated with clipping or coiling using stepwise multivariate logistic regression analysis.

RESULTS Of the 469 patients admitted to the authors’ institution with aSAH who met the study’s inclusion criteria, 144 were treated with clipping and 325 were treated with coiling. In the clipping group, the frequency of poor functional outcome was higher in patients with BMI ≥ 32.3 kg/m2 (47.6% vs 19.0%; p = 0.007). In contrast, in the coiling group, patients with BMI ≥ 32.3 kg/m2 had a lower frequency of poor functional outcome at ≥ 90 days (5.8% vs 30.9%; p < 0.001). On multivariate analysis, high BMI was independently associated with an increased (OR 3.92, 95% CI 1.20–13.41; p = 0.024) and decreased (OR 0.13, 95% CI 0.03–0.40; p < 0.001) likelihood of poor functional outcome for patients treated with clipping and coiling, respectively. For patients in the surgical group, BMI ≥ 28.4 kg/m2 was independently associated with incidence of cerebral hypodensities during admission (OR 2.44, 95% CI 1.16–5.25; p = 0.018) on multivariate analysis. For patients treated with coiling, BMI ≥ 33.2 kg/m2 was independently associated with reduced odds of hypodensities (OR 0.45, 95% CI 0.21–0.89; p = 0.021).

CONCLUSIONS The results of this study suggest that BMI may differentially affect functional outcomes after aSAH, depending on treatment modality. These findings may aid in treatment selection for patients with aSAH.

 

Radiation-Induced Changes After Stereotactic Radiosurgery for Brain Arteriovenous Malformations

Neurosurgery 83:365–376, 2018

Radiation-induced changes (RICs) are the most common complication of stereotactic radiosurgery (SRS) for brain arteriovenous malformations (AVMs), and they appear as perinidal T2-weighted hyperintensities on magnetic resonance imaging, with or without associated neurological symptoms.

OBJECTIVE: To determine the rates of RIC after AVM SRS and identify risk factors.

METHODS: A literature review was performed using PubMed and MEDLINE to identify studies reporting RIC in AVM patients treated with SRS. RICs were classified as radiologic (any neuroimaging evidence), symptomatic (any associated neurological deterioration, regardless of duration), and permanent (neurological decline without recovery). Baseline, treatment, and outcomes data were extracted for statistical analysis.

RESULTS: Based on pooled data from 51 studies, the overall rates of radiologic, symptomatic, and permanent RIC after AVMSRS were 35.5% (1143/3222 patients, 32 studies), 9.2% (499/5447 patients, 46 studies), and 3.8% (202/5272 patients, 39 studies), respectively. Radiologic RIC was significantly associated with lack of prior AVM rupture (odds ratio [OR] = 0.57; 95% confidence interval [CI]: 0.47-0.69; P < .001) and treatment with repeat SRS (OR = 6.19; 95% CI: 2.42-15.85; P < .001). Symptomatic RIC was significantly associated with deep AVM location (OR = 0.38; 95% CI: 0.21-0.67; P< .001).

CONCLUSION: Approximately 1 in 3 patients with AVMs treated with SRS develop radiologically evident RIC, and of those with radiologic RIC, 1 in 4 develop neurological symptoms. Lack of prior AVM hemorrhage and repeat SRS are risk factors for radiologic RIC, and deep nidus location is a risk factor for symptomatic RIC.

Favorable clinical outcome following surgical evacuation of deep-seated and lobar supratentorial intracerebral hemorrhage

Acta Neurochirurgica (2018) 160:1737–1747

In spontaneous supratentorial intracerebral hemorrhage (ICH), the role of surgical treatment remains controversial, particularly in deep-seated ICHs. We hypothesized that early mortality and long-term functional outcome differ between patients with surgically treated lobar and deep-seated ICH.

Method Patients who underwent craniotomy for ICH evacuation from 2009 to 2015 were retrospectively evaluated and categorized into two subgroups: lobar and deep-seated ICH. The modified Rankin Scale (mRS) was used to evaluate long-term functional outcome.

Result Of the 123 patients operated for ICH, 49.6%(n = 61) had lobar and 50.4%(n = 62) deep-seated ICH. At long-term followup (mean 4.2 years), 25 patients (20.3%) were dead, while 51.0% of survivors had a favorable outcome (mRS score ≤ 3). Overall mortality was 13.0% at 30 days and 17.9% at 6 months post-ictus, not influenced by ICH location. Mortality was higher in patients ≥ 65 years old (p = 0.020). The deep-seated group had higher incidence and extent of intraventricular extension, younger age (52.6 ± 9.0 years vs. 58.5 ± 9.8 years; p < 0.05), more frequently pupillary abnormalities, and longer neurocritical care stay (p < 0.05). The proportion of patients with good outcome was 48.0% in deep-seated vs. 54.1% in lobar ICH (p = 0.552). In lobar ICH, independent predictors of long-term outcome were age, hemorrhage volume, preoperative level of consciousness, and pupillary reaction. In deep-seated ICHs, only high age correlated significantly with poor outcome.

Conclusions At long-term follow-up, most ICH survivors had a favorable clinical outcome. Neither mortality nor long-term functional outcome differed between patients operated for lobar or deep-seated ICH. A combination of surgery and neurocritical care can result in favorable clinical outcome, regardless of ICH location.

 

Idiopathic intracranial hypertension: 120-day clinical, radiological, and manometric outcomes after stent insertion into the dural venous sinus

J Neurosurg 129:723–731, 2018

Idiopathic intracranial hypertension (IIH) is commonly associated with venous sinus stenosis. In recent years, transvenous dural venous sinus stent (DVSS) insertion has emerged as a potential therapy for resistant cases. However, there remains considerable uncertainty over the safety and efficacy of this procedure, in particular the incidence of intraprocedural and delayed complications and in the longevity of sinus patency, pressure gradient obliteration, and therapeutic clinical outcome. The aim of this study was to determine clinical, radiological, and manometric outcomes at 3–4 months after DVSS in this treated IIH cohort.

METHODS Clinical, radiographic, and manometric data before and 3–4 months after DVSS were reviewed in this single-center case series. All venographic and manometric procedures were performed under local anesthesia with the patient supine.

RESULTS Forty-one patients underwent DVSS venography/manometry within 120 days. Sinus pressure reduction of between 11 and 15 mm Hg was achieved 3–4 months after DVSS compared with pre-stent baseline, regardless of whether the procedure was primary or secondary (after shunt surgery). Radiographic obliteration of anatomical stenosis correlating with reduction in pressure gradients was observed. The complication rate after DVSS was 4.9% and stent survival was 87.8% at 120 days. At least 20% of patients developed restenosis following DVSS and only 63.3% demonstrated an improvement or resolution of papilledema.

CONCLUSIONS Reduced venous sinus pressures were observed at 120 days after the procedure. DVSS showed lower complication rates than shunts, but the clinical outcome data were less convincing. To definitively compare the outcomes between DVSS and shunts in IIH, a randomized prospective study is needed.

Subarachnoid hemorrhage after surgical treatment of unruptured intracranial aneurysms

J Neurosurg 129:490–497, 2018

Only a few previous studies have investigated subarachnoid hemorrhage (SAH) after surgical treatment in patients with unruptured intracranial aneurysms (UIAs). Given the improvement in long-term outcomes of embolization, more extensive data are needed concerning the true rupture rates after microsurgery in order to provide reliable information for treatment decisions. The purpose of this study was to investigate the incidence of and risk factors for postoperative SAH in patients with surgically treated UIAs.

METHODS Data from 702 consecutive patients harboring 852 surgically treated UIAs were evaluated. Surgical treatments included neck clipping (complete or incomplete), coating/wrapping, trapping, proximal occlusion, and bypass surgery. Clippable UIAs were defined as UIAs treated by complete neck clipping. The annual incidence of postoperative SAH and risk factors for SAH were studied using Kaplan-Meier survival analysis and Cox proportional hazards regression models.

RESULTS The patients’ median age was 64 years (interquartile range [IQR] 56–71 years). Of 852 UIAs, 767 were clippable and 85 were not. The mean duration of follow-up was 731 days (SD 380 days). During 1708 aneurysm years, there were 4 episodes of SAH, giving an overall average annual incidence rate of 0.23% (95% CI 0.12%–0.59%) and an average annual incidence rate of 0.065% (95% CI 0.0017%–0.37%) for clippable UIAs (1 episode of SAH, 1552 aneurysmyears). Basilar artery location (adjusted hazard ratio [HR] 23, 95% CI 2.0–255, p = 0.0012) and unclippable UIA status (adjusted HR 15, 95% CI 1.1–215, p = 0.046) were significantly related to postoperative SAH. An excellent outcome (modified Rankin Scale score of 0 or 1) was achieved in 816 (95.7%) of 852 cases overall and in 748 (98%) of 767 clippable UIAs at 12 months.

CONCLUSIONS In this large case series, microsurgical treatment of UIAs was found to be safe and effective. Aneurysm location and unclippable morphologies were related to postoperative SAH in patients with surgically treated UIAs.

 

Development of a statistical model for discrimination of rupture status in posterior communicating artery aneurysms

Acta Neurochirurgica (2018) 160:1643–1652

Intracranial aneurysms at the posterior communicating artery (PCOM) are known to have high rupture rates compared to other locations. We developed and internally validated a statistical model discriminating between ruptured and unruptured PCOM aneurysms based on hemodynamic and geometric parameters, angio-architectures, and patient age with the objective of its future use for aneurysm risk assessment.

Methods A total of 289 PCOM aneurysms in 272 patients modeled with image-based computational fluid dynamics (CFD) were used to construct statistical models using logistic group lasso regression. These models were evaluated with respect to discrimination power and goodness of fit using tenfold nested cross-validation and a split-sample approach to mimic external validation.

Results The final model retained maximum and minimum wall shear stress (WSS), mean parent artery WSS, maximum and minimum oscillatory shear index, shear concentration index, and aneurysm peak flow velocity, along with aneurysm height and width, bulge location, non-sphericity index, mean Gaussian curvature, angio-architecture type, and patient age. The corresponding area under the curve (AUC) was 0.8359. When omitting data from each of the three largest contributing hospitals in turn, and applying the corresponding model on the left-out data, the AUCs were 0.7507, 0.7081, and 0.5842, respectively.

Conclusions Statistical models based on a combination of patient age, angio-architecture, hemodynamics, and geometric characteristics can discriminate between ruptured and unruptured PCOM aneurysms with an AUC of 84%. It is important to include data from different hospitals to create models of aneurysm rupture that are valid across hospital populations.

Indocyanine Green Videoangiography in Aneurysm Surgery: Systematic Review and Meta-Analysis

Neurosurgery, 83 (2): 166–180

Although digital subtraction angiography (DSA) may be considered the gold standard for intraoperative vascular imaging, many neurosurgical centers rely only on indocyanine green videoangiography (ICG-VA) for the evaluation of clipping accuracy. Many studies have compared the results of ICG-VA with those of intraoperative DSA; however, a systematic review summarizing these results is still lacking.
OBJECTIVE
To analyze the literature in order to evaluate ICG-VA accuracy in the identification of aneurysm remnants and vessel stenosis after aneurysm clipping.
METHODS
We performed a systematic literature review of ICG-VA accuracy during aneurysm clipping as compared to microscopic visual observation (primary endpoint 1) and DSA (primary endpoint 2). Quality of studies was assessed with the QUADAS-2 tool. Meta-analysis was performed using a random effects model.
RESULTS
The initial PubMed search resulted in 2871 records from January 2003 to April 2016; of these, 20 articles were eligible for primary endpoint 1 and 11 for primary endpoint 2. The rate of mis-clippings that eluded microscopic visual observation and were identified at ICG-VA was 6.1% (95% CI: 4.2-8.2), and the rate of mis-clippings that eluded ICG-VA and were identified at DSA was 4.5% (95% CI: 1.8-8.3).

CONCLUSION
Because a proportion of mis-clippings cannot be identified with ICG-VA, this technique should still be considered complementary rather than a replacement to DSA during aneurysm surgery. Incorporating other intraoperative tools, such as flowmetry or electrophysiological monitoring, can obviate the need for intraoperative DSA for the identification of vessel stenosis. Nevertheless, DSA likely remains the best tool for the detection of aneurysm remnants.

Microsurgical Clipping of Ruptured Anterosuperior-Projecting Anterior Communicating Artery Aneurysms: How We Do It

World Neurosurg. (2018) 116:133-135

In anterosuperior-projecting anterior communicating artery (ACoA) aneurysms, the aneurysm dome usually adheres to 1 or both proximal A2 segments, which may present technical difficulties. This video demonstrates microsurgical clipping of a ruptured anterosuperior-projecting ACoA aneurysm. A 52-year-old male presented with a Hunt-Hess grade II subarachnoid hemorrhage. Computed tomography showed subarachnoid hemorrhage in the basal cisterns and sylvian and interhemispheric fissures. Angiography demonstrated a wide-necked ACoA aneurysm projecting anterosuperiorly. Considering the risk of recurrence, the patient decided to accept surgical treatment.

The patient was positioned supine, and the aneurysm was exposed via the lateral supraorbital approach. The carotid cistern and optic cistern were opened to release cerebrospinal fluid and achieve adequate brain relaxation. A subpial resection of a small portion of the gyrus rectus was performed to visualize the ipsilateral A2, recurrent artery of Heubner, and base of the aneurysm. A plane was dissected between the anterior aspect of both the A2 segment and posterior aspect of the aneurysm. A straight clip was placed parallel to the ACoA to completely obliterate the aneurysm. Postoperative angiography confirmed complete obliteration of the aneurysm. The patient recovered well without any complications.

Successful treatment requires preoperative surgical planning, precise dissection, and preservation of critical structures. With adherence to these general principles, these aneurysms can be treated safely and effectively.

Cranial nerve deficits in giant cavernous carotid aneurysms and their relation to aneurysm morphology and location

Acta Neurochirurgica (2018) 160:1653–1660

Giant cavernous carotid aneurysms (GCCAs) usually exert substantial mass effect on adjacent intracavernous cranial nerves. Since predictors of cranial nerve deficits (CNDs) in patients with GCCA are unknown, we designed a study to identify associations between CND and GCCA morphology and the location of mass effect.

Methods This study was based on data from the prospective clinical and imaging databases of the Giant Intracranial Aneurysm Registry. We used magnetic resonance imaging and digital subtraction angiography to examine GCCA volume, presence of partial thrombosis (PT), GCCA origins, and the location of mass effect. We also documented whether CND was present.

Results We included 36 GCCA in 34 patients, which had been entered into the registry by eight participating centers between January 2009 and March 2016. The prevalence of CND was 69.4%, with one CND in 41.7% and more than one in 27.5%. The prevalence of PT was 33.3%. The aneurysm origin was most frequently located at the anterior genu (52.8%). The prevalence of CND did not differ between aneurysm origins (p = 0.29). Intracavernous mass effect was lateral in 58.3%, mixed medial/lateral in 27.8%, and purely medial in 13.9%. CND occurred significantly more often in GCCA with lateral (81.0%) or mixed medial/lateral (70.0%)mass effect than in GCCA with medial mass effect (20.0%; p = 0.03). After adjusting our data for the effects of the location of mass effect, we found no association between the prevalence of CND and aneurysm volume (odds ratio (OR) 1.30 (0.98–1.71); p = 0.07), the occurrence of PT (OR 0.64 (0.07–5.73); p = 0.69), or patient age (OR 1.02 (95% CI 0.95–1.09); p = 0.59).

Conclusions Distinguishing between medial versus lateral location of mass effect may be more helpful than measuring aneurysm volumes or examining aneurysm thrombosis in understanding why some patients with GCCA present with CND while others do not.

Minimally Invasive Surgery is Superior to Conventional Craniotomy in Patients with Spontaneous Supratentorial Intracerebral Hemorrhage: A Systematic Review and Meta-Analysis

World Neurosurg. (2018) 115:266-273

Outcomes of minimally invasive surgery (MIS) versus conventional craniotomy (CC) for patients with spontaneous supratentorial intracerebral hemorrhage (SICH) have not been compared previously. We reviewed the current evidence regarding the safety and efficacy of MIS compared with CC in patients with SICH.

METHODS: We conducted a meta-analysis of studies comparing MIS and CC in patients with computed tomography confirmed SICH published between January 2000 and April 2018 in MEDLINE, Embase, and the Cochrane Controlled Trials Register based on PRISMA inclusion and exclusion criteria. Binary outcomes comparisons between MIS and CC were described using odds ratios (ORs).

RESULTS: Five randomized controlled trials (RCTs) and 9 prospective controlled studies (non-RCTs), involving a total of 2466 patients, met our inclusion criteria. There was a statistically significant difference in mortality rate between MIS and CC (OR, 0.76; 95% confidence interval [CI], 0.60e0.97). MIS was associated with a lower rate of rebleeding (OR, 0.42; 95% CI, 0.28e0.64) and a higher rate of good recovery compared with CC (OR, 2.27; 95% CI, 1.34e3.83).

CONCLUSIONS: Patients with SICH may benefit more from MIS than CC. Our study could help clinicians optimize treatment strategies in SICH