Category: Vascular

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Silent Arteriovenous Malformation Hemorrhage and the Recognition of “Unruptured” Arteriovenous Malformation Patients Who Benefit From Surgical Intervention

Silent Arteriovenous Malformation Hemorrhage and the Recognition of “Unruptured” Arteriovenous Malformation Patients Who Benefit From Surgical Intervention

Neurosurgery 76:592–600, 201

Arteriovenous malformation (AVM) patients present in 4 ways relative to hemorrhage: (1) unruptured, without a history or radiographic evidence of old hemorrhage (EOOH); (2) silent hemorrhage, without a bleeding history but with EOOH; (3) ruptured, with acute bleeding but without EOOH; and (4) reruptured, with acute bleeding and EOOH. OBJECTIVE: We hypothesized that characteristics and outcomes in the unrecognized group of silent hemorrhage patients may differ from those of unruptured patients.

METHODS: Two hundred forty-two patients operated-on since 1997 were categorized by hemorrhage status and hemosiderin positivity in this cohort study: unruptured (group 1), silent hemorrhage (group 2), and ruptured/reruptured (group 3/4). Group 3/4 was combined because hemosiderin cannot distinguish acute hemorrhage from older silent hemorrhage.

RESULTS: Hemosiderin was found in 45% of specimens. Seventy-five patients (31.0%) had unruptured AVMs, 30 (12.4%) had silent hemorrhage, and 137 (56.6%) had ruptured/ reruptured AVMs. Deep drainage, posterior fossa location, preoperative modified Rankin Scale (mRS) score, outcome, and macrophage score were different across groups. Only the macrophage score was different between the groups without clinical hemorrhage. Outcomes were better in silent hemorrhage patients than in those with frank rupture (mean mRS scores of 1.2 and 1.7, respectively).

CONCLUSION: One-third of patients present with silent AVM hemorrhage. No clinical or anatomic features differentiate these patients from unruptured patients, except the presence of hemosiderin and macrophages. Silent hemorrhage can be diagnosed using magnetic resonance imaging with iron-sensitive imaging. Silent hemorrhage portends an aggressive natural history, and surgery halts progression to rerupture. Good final mRS outcomes and better outcomes than in those with frank rupture support surgery for silent hemorrhage patients, despite the findings of ARUBA.

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Endovascular and Surgical Treatment of Internal Carotid Bifurcation Aneurysms: Comparison of Results, Outcome, and Mid-Term Follow-up

Categorization of aneurysms by their origin and projection

Neurosurgery 76:540–551, 2015

Aneurysms of the internal carotid artery (ICA) bifurcation are rare, and no studies have compared patient outcomes after endovascular vs surgical treatment.

OBJECTIVE: To report the safety, efficacy, and follow-up outcome of these 2 treatment options for patients with ICA bifurcation aneurysms.

METHODS: Patient and aneurysm characteristics, treatment results, and follow-up outcomes (at 30 months) were analyzed from patient records and review of imaging findings.

RESULTS: A total of 58 patients with ICA bifurcation aneurysms were treated. By interdisciplinary consensus, 30 aneurysms were assigned for coiling and 28 for clipping. Patients who underwent surgical clipping were younger and had larger aneurysms. More patients were assigned to coiling if their aneurysms originated only from the ICA bifurcation or projected superiorly. For the combined angiographic endpoint, complete and nearly complete occlusion (Raymond-Roy I + II), similar rates of 96% (coiling) or 100% (clipping) could be achieved. Raymond-Roy I occlusion occurred more often after clipping (79% vs 41% coiling). Follow-up of the endovascular group showed minor recanalization of the aneurysm neck (Raymond-Roy II) in 42%. One patient (4%) showed a major recanalization (Raymond-Roy III) and needed re-treatment. For incidental findings, no bleeding complications or new persistent neurological deficits occurred during follow-up.

CONCLUSION: Treatment of ICA bifurcation aneurysms after interdisciplinary assignment to clipping or coiling is effective and safe. Despite significantly more minor recanalizations after coiling, the re-treatment rate was very low, and no bleeding was observed during follow-up. Multivariate analysis revealed that origin only from the ICA bifurcation was an independent predictor of aneurysm recanalization after endovascular treatment.

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Cerebral Venous Sinus Thrombosis on Unenhanced CT

Cerebral Venous Sinus Thrombosis on Unenhanced CT

Neurosurg Q 2015;25:154–160

The aim of the study was to investigate computed tomography (CT) signs of cerebral venous sinus thrombosis (CVST), so as to increase clinicians’ awareness of CVST and improve the sensitivity of the diagnosis.

Materials and Methods: We retrospectively analyzed all the CVST cases primary diagnosed by CT and confirmed further by magnetic resonance imaging (MRI) or other clinical methods within the past 4 years in our institution. In total, 11 cases including 6 male and 5 female patients with a mean age of 31.0 years were studied. All patients had emergency CT examination for complaints of headache. The initial CT examinations were performed within 7 days after the onset in 7 cases and over 7 days in the other 4 cases. Six cases had continuous follow-up CT examinations, twice in 4 and 3 times in 2. The analysis items focus on the density change by measuring the CT values of involved venous sinuses in different phases, as well as indirect signs including venous infarction and hemorrhage. As a comparison, we measured CT values of normal venous sinuses in 40 healthy people with age ranging from 20 to 60 years.

Results: Of the patients with CT examinations performed within a week after the onset, 6 cases displayed uniform high density in related venous sinuses with a mean value of 72 HU. One week later, the densities declined slightly or reached isodensity with a mean value of 58 HU. The follow-up CT demonstrated the density changes of sinuses with the extension of the course of CVST, from high density gradually attenuating into mixed density, and into isodensity at last. During 7 to 10 days after the onset in 3 cases, the involved sinuses showed central high density with peripheral isodensity. A change of involved sinuses from high-density to isodensity occurring in different sites was found in 1 case on follow-up CT. Cortical vein thrombosis with secondary hemorrhage in 2 cases and CVST with subarachnoid hemorrhage in 2 cases were revealed in our study.

Conclusions: On CT, the CVST presented as the attenuation of the sinuses from high to isodensity with its resolution course. In the first week, the involved sinuses mainly appear as high density, then in 7 to 10 days decrease to mixed density as central high density and peripheral isodensity, and gradually to uniform isodensity at last. The secondary infarction and hemorrhage are important indirect signs of CVST. Understanding the abnormal density change of venous sinuses and intracerebral indirect signs on CT could improve our diagnostic sensitivity for CVST.

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The role of microscope-integrated near-infrared indocyanine green videoangiography in the surgical treatment of intracranial dural arteriovenous fistulas

The role of microscope-integrated near-infrared indocyanine green videoangiography in the surgical treatment of intracranial dural arteriovenous fistulas

J Neurosurg 122:876–882, 2015

The successful treatment of an intracranial dural arteriovenous fistula (dAVF) requires complete obliteration of blood flow through the fistulous point. Surgical ligation is often used along with endovascular techniques. Digital subtraction angiography (DSA) can be used to confirm fistula obliteration; however, this technique can be cumbersome intraoperatively and difficult to correlate anatomically with the surgical field. Near-infrared indocyanine green (ICG) videoangiography has been described as a complementary tool for this purpose.

Methods The authors examined intracranial dAVF cases in which microscope-integrated intraoperative ICG videoangiography was used to identify and/or confirm obliteration of the dAVF during surgery. Retrospective evaluation of all intracranial dAVF cases treated with surgical ligation over a 10-year period at the Barrow Neurological Institute (n = 47) revealed 28 cases in which ICG videoangiography was used. The results were compared with findings on preoperative and intraoperative or postoperative DSA.

Results ICG videoangiography successfully confirmed the fistulous point intraoperatively in 96% (22/23) of the cases. It also revealed complete obliteration of fistulas, comparable to intraoperative or postoperative DSA, in 91% (21/23) of the cases. The false-negative rate of ICG was 8.7% (2/23), which is similar to the false-negative rate of intraoperative DSA alone (10.5% [2/19]).

Conclusions Microscope-based ICG videoangiography provides real-time information about the intraoperative anatomy of dAVFs. In addition, it can confirm complete obliteration of a fistula. This technique may be useful during dAVF surgery as an independent form of angiography or as an adjunct to intraoperative or postoperative DSA.

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Stratification of Recanalization for Patients With Endovascular Treatment of Intracranial Aneurysms

Recanalization for Patients With Endovascular Treatment of Intracranial Aneurysms

Neurosurgery 76:390–395, 2015

With the increasing use of endovascular techniques in the treatment of both ruptured and unruptured intracranial aneurysms, the issue of obliteration efficacy has become increasingly important.

OBJECTIVE: To systematically develop a comprehensive model for predicting retreatment with various types of endovascular treatment.

METHODS: We retrospectively reviewed medical records that were prospectively collected for 305 patients who received endovascular treatment for intracranial aneurysms from 2007 to 2013. Multivariable logistic regression was performed on candidate predictors identified by univariable screening analysis to detect independent predictors of retreatment. A composite risk score was constructed based on the proportional contribution of independent predictors in the multivariable model.

RESULTS: Size (.10 mm), aneurysm rupture, stent assistance, and posttreatment degree of aneurysm occlusion were independently associated with retreatment, whereas intraluminal thrombosis and flow diversion demonstrated a trend toward retreatment. The Aneurysm Recanalization Stratification Scale was constructed by assigning the following weights to statistically and clinically significant predictors: aneurysm-specific factors: size (.10 mm), 2 points; rupture, 2 points; presence of thrombus, 2 points. Treatment-related factors were stent assistance, 21 point; flow diversion, 22 points; Raymond Roy occlusion class 2, 1 point; Raymond Roy occlusion class 3, 2 points. This scale demonstrated good discrimination with a C-statistic of 0.799.

CONCLUSION: Surgical decision making and patient-centered informed consent require comprehensive and accessible information on treatment efficacy. We constructed the Aneurysm Recanalization Stratification Scale to enhance this decisionmaking process. This is the first comprehensive model that has been developed to quantitatively predict the risk of retreatment after endovascular therapy.

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Current surgical results with low-grade brain arteriovenous malformations

Low-grade brain arteriovenous malformations

J Neurosurg 122:912–920, 2015

Resection is an appealing therapy for brain arteriovenous malformations (AVMs) because of its high cure rate, low complication rate, and immediacy, and has become the first-line therapy for many AVMs. To clarify safety, efficacy, and outcomes associated with AVM resection in the aftermath of A Randomized Trial of Unruptured Brain AVMs (ARUBA), the authors reviewed their experience with low-grade AVMs—the most favorable AVMs for surgery and the ones most likely to have been selected for treatment outside of ARUBA’s randomization process.

Methods A prospective AVM registry was searched to identify patients with Spetzler-Martin Grade I and II AVMs treated using resection during a 16-year period.

Results Of the 232 surgical patients included, 120 (52%) presented with hemorrhage, 33% had Spetzler-Martin Grade I, and 67% had Grade II AVMs. Overall, 99 patients (43%) underwent preoperative embolization, with unruptured AVMs embolized more often than ruptured AVMs. AVM resection was accomplished in all patients and confirmed angiographically in 218 patients (94%). There were no deaths among patients with unruptured AVMs. Good outcomes (modified Rankin Scale [mRS] score 0–1) were found in 78% of patients, with 97% improved or unchanged from their preoperative mRS scores. Patients with unruptured AVMs had better functional outcomes (91% good outcome vs 65% in the ruptured group, p = 0.0008), while relative outcomes were equivalent (98% improved/unchanged in patients with ruptured AVMs vs 96% in patients with unruptured AVMs).

Conclusions Surgery should be regarded as the “gold standard” therapy for the majority of low-grade AVMs, utilizing conservative embolization as a preoperative adjunct. High surgical cure rates and excellent functional outcomes in patients with both ruptured and unruptured AVMs support a dominant surgical posture for low-grade AVMS, with radiosurgery reserved for risky AVMs in deep, inaccessible, and highly eloquent locations. Despite the technological advances in endovascular and radiosurgical therapy, surgery still offers the best cure rate, lowest risk profile, and greatest protection against hemorrhage for low-grade AVMs. ARUBA results are influenced by a low randomization rate, bias toward nonsurgical therapies, a shortage of surgical expertise, a lower rate of complete AVM obliteration, a higher rate of delayed hemorrhage, and short study duration. Another randomized trial is needed to reestablish the role of surgery in unruptured AVM management.

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Aneurysm diameter as a risk factor for pretreatment rebleeding: a meta-analysis

MCA aneurysm

J Neurosurg 122:921–928, 2015

Aneurysmal rerupture prior to treatment is a major cause of death and morbidity in aneurysmal subarachnoid hemorrhage. Recognizing risk factors for aneurysmal rebleeding is particularly relevant and might help to identify the aneurysms that benefit from acute treatment. It is uncertain if the size of the aneurysm is related to rebleeding. This meta-analysis was performed to evaluate whether an association could be determined between aneurysm diameter and the rebleeding rate before treatment. Potentially confounding factors such age, aneurysm location, and the presence of hypertension were also evaluated.

Methods The authors systematically searched the PubMed, Embase, and Cochrane databases up to April 3, 2013, for studies of patients with aneurysmal subarachnoid hemorrhage that reported the association between aneurysm diameter and pretreatment aneurysmal rebleeding. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria were used to evaluate study quality.

Results Seven studies, representing 2121 patients, were included in the quantitative analysis. The quality of the studies was low in 2 and very low in 5. Almost all of the studies used 10 mm as the cutoff point for size among other classes, and only one used 7 mm. An analysis was performed with this best unifiable cutoff point. Overall rebleeding occurred in 360 (17.0%) of 2121 patients (incidence range, from study to study, 8.7%–28.4%). The rate of rebleeding in small and large aneurysms was 14.0% and 23.6%, respectively. The meta-analysis of the 7 studies revealed that larger size aneurysms were at a higher risk for rebleeding (OR 2.56 [95% CI 1.62–4.06]; p = 0.00; I2 = 60%). The sensitivity analysis did not alter the results. Five of the 7 studies reported data regarding age; 4 studies provided age-adjusted results and identified a persistent relationship between lesion size and the risk of rebleeding. The presence of hypertension was reported in two studies and was more prevalent in patients with rebleeding in one of these. Location (anterior vs posterior circulation) was reported in 5 studies, while in 4 there was no difference in the rebleeding rate. One study identified a lower risk of rebleeding associated with posterior location aneurysms.

Conclusions This meta-analysis showed that aneurysm size is an important risk factor for aneurysmal rebleeding and should be used in the clinical risk assessment of individual patients. The authors’ results confirmed the current guidelines and underscored the importance of acute treatment for large ruptured aneurysms.

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The utility of preoperative diffusion tensor imaging in the surgical management of brainstem cavernous malformations

The utility of preoperative diffusion tensor imaging in the surgical management of brainstem cavernous malformations

J Neurosurg 122:653–662, 2015

Resection of brainstem cavernous malformations (BSCMs) may reduce the risk of stepwise neurological deterioration secondary to hemorrhage, but the morbidity of surgery remains high. Diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) are neuroimaging techniques that may assist in the complex surgical planning necessary for these lesions. The authors evaluate the utility of preoperative DTI and DTT in the surgical management of BSCMs and their correlation with functional outcome.

Methods A retrospective review was conducted to identify patients who underwent resection of a BSCM between 2007 and 2012. All patients had preoperative DTI/DTT studies and a minimum of 6 months of clinical and radiographic follow-up. Five major fiber tracts were evaluated preoperatively using the DTI/DTT protocol: 1) corticospinal tract, 2) medial lemniscus and medial longitudinal fasciculus, 3) inferior cerebellar peduncle, 4) middle cerebellar peduncle, and 5) superior cerebellar peduncle. Scores were applied according to the degree of distortion seen, and the sum of scores was used for analysis. Functional outcomes were measured at hospital admission, discharge, and last clinic visit using modified Rankin Scale (mRS) scores.

Results Eleven patients who underwent resection of a BSCM and preoperative DTI were identified. The mean age at presentation was 49 years, with a male-to-female ratio of 1.75:1. Cranial nerve deficit was the most common presenting symptom (81.8%), followed by cerebellar signs or gait/balance difficulties (54.5%) and hemibody anesthesia (27.2%). The majority of the lesions were located within the pons (54.5%). The mean diameter and estimated volume of lesions were 1.21 cm and 1.93 cm3, respectively. Using DTI and DTT, 9 patients (82%) were found to have involvement of 2 or more major fiber tracts; the corticospinal tract and medial lemniscus/medial longitudinal fasciculus were the most commonly affected. In 2 patients with BSCMs without pial presentation, DTI/DTT findings were important in the selection of the surgical approach. In 2 other patients, the results from preoperative DTI/DTT were important for selection of brainstem entry zones. All 11 patients underwent gross-total resection of their BSCMs. After a mean postoperative follow-up duration of 32.04 months, all 11 patients had excellent or good outcome (mRS Score 0–3) at the time of last outpatient clinic evaluation. DTI score did not correlate with long-term outcome.

Conclusions Preoperative DTI and DTT should be considered in the resection of symptomatic BSCMs. These imaging studies may influence the selection of surgical approach or brainstem entry zones, especially in deep-seated lesions without pial or ependymal presentation. DTI/DTT findings may allow for more aggressive management of lesions previously considered surgically inaccessible. Preoperative DTI/DTT changes do not appear to correlate with functional postoperative outcome in long-term follow-up.

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A prospective comparative study of microscope-integrated intraoperative fluorescein and indocyanine videoangiography for clip ligation of complex cerebral aneurysms

A prospective comparative study of microscope-integrated intraoperative fluorescein and indocyanine videoangiography for clip ligation of complex cerebral aneurysms

J Neurosurg 122:618–626, 2015

The authors prospectively analyzed 2 microscope-integrated videoangiography techniques using intravenous indocyanine green (ICG) and fluorescein for assessment of cerebral aneurysm obliteration and adjacent vessel patency.

Methods The authors prospectively enrolled 22 patients who underwent clip ligation of their aneurysm and used intraoperative videoangiography to assess obliteration of the aneurysmal sac and patency of the adjacent branching and perforating arteries. Patients underwent ICG videoangiography (ICG-VA) and the newly developed fluorescein videoangiography (FL-VA) using microscope-integrated fluorescence modules. Two independent observers compared the videoangiography recordings for value and quality to assess aneurysm exclusion and the patency of adjacent arteries.

Results All 22 patients first underwent FL-VA and then ICG-VA after clip application. In 7 cases (32%), FL-VA provided superior detail to assess perforating arteries (4 cases), distal branches (2 cases), and both (1 case); such detail was not readily available on ICG-VA. In 1 patient, ICG-VA offered better visualization of posterior communicating artery aneurysm occlusion than FL-VA because of staining artifact on the aneurysm dome from the adjacent tentorium. In 2 patients, FL-VA offered the needed advantage of real-time manipulation of the vessels and flow assessment by visualization through the operating microscope oculars. In 2 other cases, ICG-VA was more practical for repeat usage because of its more efficient clearance from the intravascular space. The ICG-VA image quality was often degraded at higher magnification in deep operative fields, partly due to chromatic aberration. Both ICG-VA and FL-VA afforded restricted views of vasculature based on the angle of surgical approach and obscuration by blood clot, aneurysm, or brain tissue.

Conclusions Compared with ICG-VA, FL-VA can potentially provide an improved visualization of vasculature at high magnification in deep surgical fields. ICG-VA is more effective for repeated use during clip repositioning due to ICG’s minimal vascular wall extravasation. Therefore, in certain cases, FL-VA may offer some advantages and play a complementary role along with ICG-VA in intraoperative fluorescence evaluation during microsurgical management of aneurysms.

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Novel Device and Technique for Minimally Invasive Intracerebral Hematoma Evacuation in the Same Setting of a Ruptured Intracranial Aneurysm

Novel Device and Technique for Minimally Invasive Intracerebral Hematoma Evacuation in the Same Setting of a Ruptured Intracranial Aneurysm

Operative Neurosurgery 11:43–51, 2015

The presence of intracerebral hematoma from aneurysm rupture is an indication for craniotomy for clot evacuation and aneurysm clipping. Some centers have begun securing aneurysms with coil embolization followed by clot evacuation in the operating room. This approach requires transporting a patient from the angiography suite to the operating room, which can take valuable time and resources.

OBJECTIVE: To report our experience with 3 cases in which a novel technique for minimally invasive evacuation of intracerebral hematomas after endovascular treatment of ruptured intracranial aneurysms was used. The Penumbra Apollo system can be used in the angiography suite in conjunction with neuroendovascular techniques to simultaneously address a symptomatic hematoma associated with a ruptured aneurysm.

METHODS: Standard preoperative computed tomography angiography was performed on arrival to the emergency department. The patients underwent diagnostic cerebral angiography followed by balloon-assisted coil embolization and then remained in the neurointerventional suite for intracerebral hematoma evacuation with the Apollo system.

RESULTS: All patients tolerated coil embolization and hematoma evacuation well. The combined procedures lasted <3 hours in both cases. Two patients were eventually discharged to acute rehabilitation facilities less than a month after their initial insult, and 1 has been cleared to return to work. The other patient was transferred to hospice care.

CONCLUSION: The Apollo aspiration system appears to be a safe and effective minimally invasive option for intracerebral hematoma evacuation, particularly when coupled with endovascular embolization of ruptured intracranial aneurysms. Future work will address which patient population is most likely to benefit from this promising technique.

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Diffusion-weighted imaging–detected ischemic lesions associated with flow-diverting stents in intracranial aneurysms

Diffusion-weighted imaging–detected ischemic lesions associated with flow-diverting stents in intracranial aneurysms

J Neurosurg 122:627–636, 2015

It was initially considered safe for flow-diverting stents to cover the ostia of branching vessels during endovascular procedures for the treatment of intracranial aneurysms. As more recent evidence suggests, however, their use is not always free of ischemic concerns in terms of covered arterial ostia. The authors sought to determine the frequency of silent and clinically evident diffusion-weighted imaging (DWI)–detected abnormalities related to stent placement as a means of elucidating potential clinical risks.

Methods This is a prospective single-center study on a series of patients with intracranial aneurysms that were treated with flow-diverting stents. All patients systematically underwent an MRI protocol that included DWI before treatment, between 24 and 48 hours postprocedure, and 3 months postembolization. Effectiveness of anticoagulation treatment was assessed for all patients. Lesions seen on DWI were correlated to the parent artery and the side-branch territories and were statistically analyzed in relation to their time of occurrence and clinical presentation. The authors compared the DWI findings in these patients to findings obtained in patients treated with a stent-assisted coiling technique during the same time period.

Results Over the course of 18 consecutive months, 38 consecutive patients (7 males and 31 females) with 49 intracranial aneurysms were treated using flow-diverting stents. Overall, 81.6% of the DWI spots found remained clinically silent during the follow-up period. Five ischemic clinical complications (13.2%) occurred in the postprocedural period. No statistically significant correlation could be established between DWI spots or aneurysm location and clinical complications or follow-up modified Rankin Scale score at 3 months. The complication rate was 7.8% (n = 3) at the 3-month follow-up, and mortality was 0%. Compared with stent-assisted coiling, use of flow-diverting stents showed a statistically significant correlation with silent DWI findings postintervention.

Conclusions Lesions seen on DWI resulting from the procedure are far more common than anticipated, but the technique remains safe and effective, providing an interesting alternative for “difficult” aneurysms, regardless of location. Late-occurring DWI-detected lesions distal to side arterial branches imply a local pressure gradient drop, related to flow competition by collateral networks. Further research is needed to assess the extent and significance of these events.

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Surgical Management of Ruptured Middle Cerebral Artery Aneurysms With Large Intraparenchymal or Sylvian Fissure Hematomas

Ruptured MCA aneurysms

Neurosurgery 76:258–264, 2015

Craniotomy for hematoma evacuation and aneurysm clipping is the treatment modality of choice for ruptured middle cerebral artery (MCA) aneurysms with intracranial hematomas. Recent literature suggests that endovascular coil embolization followed by hematoma evacuation can be an acceptable alternative.

OBJECTIVE: To determine neurological outcomes in patients with ruptured MCA aneurysms and intraparenchymal or sylvian fissure hematomas.

METHODS: The records of 49 patients with ruptured MCA aneurysms with large intracranial hematomas treated with hematoma evacuation and aneurysm clipping between January 2000 and December 2013 were retrospectively reviewed.

RESULTS: Within this cohort, 35 patients (71.4%) were Hunt and Hess grade IV or V on presentation. The mean hematoma volume was 100.4 6 77.2 mL. Craniectomy was performed in 40 patients (81.6%). Angiographic vasospasm developed in 15 patients (30.6%). The in-hospital mortality rate was 28.6% (14 patients). At a mean of 25.3 6 34.0 months follow-up, a good outcome (modified Rankin Scale [mRS] score 0-3) was observed in 18 patients (36.7%). Significant factors associated with poor outcome or death (mRS scores of 4-6) included increasing age (P , .01), increasing Hunt and Hess grade (P = .03), increasing modified Fisher grade (P = .01), presence of intraventricular hemorrhage (P , .01), decreasing percentage of hematoma evacuation (P , .05), need for craniectomy (P ,. 01), need for external ventricular drainage (P = .04), and angiographic vasospasm (P = .02).

CONCLUSION: MCA aneurysm rupture with concomitant large intraparenchymal or sylvian fissure hematoma formation carries a grave prognosis. Simultaneous hematoma evacuation and aneurysm clipping with or without craniectomy can be an effective treatment modality.

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Comparison of indocyanine green fluorescent angiography to digital subtraction angiography in brain arteriovenous malformation surgery

ICG and AVM

Acta Neurochir (2015) 157:351–359

The potential utility of intraoperative microscope-integrated indocyanine green (ICG) fluorescence angiography in the surgery of brain arteriovenous malformations (AVMs) and evaluation of the completeness of resection is debatable. Postoperative catheter angiography is considered the gold standard. We evaluated the value of ICG and intraoperative catheter angiography in this setting.

Methods Between January 2009 and July 2013, 37 patients with brain AVMs underwent surgical resection of their vascular lesions. ICG videoangiography and an intraoperative catheter angiography were performed in 32 cases, and a routine postoperative angiogram was performed within 48 h to 2 weeks after surgery. The usefulness of ICG findings and the ability to confirm total resection and to identify residual nidus or persistent shunt were assessed and compared to intraoperative and postoperative digital subtraction angiography, respectively.

Results There were 7 grade 1, 11 grade 2, 11 grade 3 and 3 grade 4 Spetzler-Martin classification AVMs. ICG angiography helped to distinguish AVM vessels in 26 patients. In 31 patients, it demonstrated that there was no residual shunting. In one patient, a residual AVMwas identified and further resected. Intraoperative catheter angiography detected two additional small residuals that were missed by ICG angiography, both deep in the surgical cavity. Further resection of the AVM was performed, and total resection was confirmed by a repeat intraoperative angiogram. Postoperative angiography in a patient with a grade 4 lesion revealed one additional small deep residual AVM nidus with persistent late shunting missed on both ICG and intraoperative angiography. Overall ICG angiography missed three out of four residual AVMs after initial resection, while the intraoperative angiogram missed one.

Conclusion Although ICG angiography is a helpful adjunct in the surgery of some brain AVMs, it’s yield in detecting residual AVM nidus or shunt is low, especially for deepseated lesions and higher grade AVMs. ICG angiography should not be used as a sole and/or reliable technique. Highresolution postoperative angiography must be performed in brain AVM surgery and remains the best test to confidently confirm complete AVM resection.

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Brainstem Cavernous Malformations: Surgical Results in 104 Patients and a Proposed Grading System to Predict Neurological Outcomes

Brainstem Cavernous Malformations- Surgical Results in 104 Patients and a Proposed Grading System to Predict Neurological Outcomes

Neurosurgery 76:265–278, 2015

Once considered inoperable lesions in inviolable territory, brainstem cavernous malformations (BSCM) are now surgically curable with acceptable operative morbidity. Recommending surgery is a difficult decision that would be facilitated by a grading system designed specifically for BSCMs that predicted surgical outcomes.

OBJECTIVE: Informed by our efforts to develop a supplementary grading system for arteriovenous malformations, we hypothesized that a similar system might predict long-term outcomes and guide clinical decision-making.

METHODS: A consecutive, single-surgeon series of 104 patients was used to assess preoperative clinical and imaging predictors of microsurgical outcomes. Univariable logistic regression identified predictors and a multivariable logistic regression model tested the association of the combined predictors with final modified Rankin Scale scores. A grading system assigned points for lesion size, location crossing the brainstem’s midpoint, presence of developmental venous anomaly, age, and time from last hemorrhage to surgery.

RESULTS: Average maximal diameter of BSCMs was 19.5 mm; 50% crossed the axial midpoint; 54.8% had developmental venous anomalies; mean age was 42.1 years; and median time from last hemorrhage to surgery was 60 days. One patient died (0.96%), and 15 patients (14.4%) experienced worsened cranial nerve or motor dysfunction, of which 10 increased their modified Rankin Scale scores (9.6%). BSCM grades ranged from 0 to 7 points and predicted outcomes with high accuracy (receiver operating characteristic = 0.86, 95% confidence interval: 0.78-0.94).

CONCLUSION: Rather than developing a grading system for all cerebral cavernous malformations that is weak with BSCMs, we propose a system for the patients who need it most. The BSCM grading system differentiates patients who might expect favorable surgical outcomes and offers guidance to neurosurgeons forced to select these patients.

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Attrition rates in neurosurgery residency

surgeons

J Neurosurg 122:240–249, 2015

The objective of this study is to determine neurosurgery residency attrition rates by sex of matched applicant and by type and rank of medical school attended.

Methods The study follows a cohort of 1361 individuals who matched into a neurosurgery residency program through the SF Match Fellowship and Residency Matching Service from 1990 to 1999. The main outcome measure was achievement of board certification as documented in the American Board of Neurological Surgery Directory of Diplomats. A secondary outcome measure was documentation of practicing medicine as verified by the American Medical Association DoctorFinder and National Provider Identifier websites. Overall, 10.7% (n = 146) of these individuals were women. Twenty percent (n = 266) graduated from a top 10 medical school (24% of women [35/146] and 19% of men [232/1215], p = 0.19). Forty-five percent (n = 618) were graduates of a public medical school, 50% (n = 680) of a private medical school, and 5% (n = 63) of an international medical school. At the end of the study, 0.2% of subjects (n = 3) were deceased and 0.3% (n = 4) were lost to follow-up.

Results The total residency completion rate was 86.0% (n = 1171) overall, with 76.0% (n = 111/146) of women and 87.2% (n = 1059/1215) of men completing residency. Board certification was obtained by 79.4% (n = 1081) of all individuals matching into residency between 1990 and 1999. Overall, 63.0% (92/146) of women and 81.3% (989/1215) of men were board certified. Women were found to be significantly more at risk (p < 0.005) of not completing residency or becoming board certified than men. Public medical school alumni had significantly higher board certification rates than private and international alumni (82.2% for public [508/618]; 77.1% for private [524/680]; 77.8% for international [49/63]; p < 0.05). There was no significant difference in attrition for graduates of top 10–ranked institutions versus other institutions. There was no difference in number of years to achieve neurosurgical board certification for men versus women.

Conclusions Overall, neurosurgery training attrition rates are low. Women have had greater attrition than men during and after neurosurgery residency training. International and private medical school alumni had higher attrition than public medical school alumni.

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A treatment paradigm for high-grade brain arteriovenous malformations: volume-staged radiosurgical downgrading followed by microsurgical resection

A treatment paradigm for high-grade brain arteriovenous malformations- volume-staged radiosurgical downgrading followed by microsurgical resection

J Neurosurg 122:419–432, 2015

The surgical treatment of many large arteriovenous malformations (AVMs) is associated with substantial risks, and many are considered inoperable. Furthermore, AVMs larger than 3 cm in diameter are not usually treated with conventional single-session radiosurgery encompassing the entire AVM volume. Volume-staged stereotactic radiosurgery (VS-SRS) is an option for large AVMs, but it has mixed results. The authors report on a series of patients with highgrade AVMs who underwent multiple VS-SRS sessions with resultant downgrading of the AVMs, followed by resection.

Methods. A cohort of patients was retrieved from a single-institution AVM patient registry consisting of prospectively collected data. VS-SRS was performed as a planned intentional treatment. Surgery was considered as salvage therapy in select patients.

Results Sixteen AVMs underwent VS-SRS followed by surgery. Four AVMs presented with rupture. The mean patient age was 25.3 years (range 13–54 years). The average initial Spetzler-Martin grade before any treatment was 4, while the average supplemented Spetzler-Martin grade (Spetzler-Martin plus Lawton-Young) was 7.1. The average AVM size in maximum dimension was 5.9 cm (range 3.3–10 cm). All AVMs were supratentorial in location and all except one were in eloquent areas of the brain, with 7 involving primary motor cortex. The mean number of VS-SRS sessions was 2.7 (range 2–5 sessions). The mean interval between first VS-SRS session and resection was 5.7 years. There were 4 hemorrhages that occurred after VS-SRS. The average Spetzler-Martin grade was reduced to 2.5 (downgrade, -1.5) and the average supplemented Spetzler-Martin grade was reduced to 5.6 (downgrade, -1.5). The maximum AVM size was reduced to an average of 3.0 cm (downsize = -2.9 cm). The mean modified Rankin Scale (mRS) scores were 1.2, 2.3, and 2.2 before VS-SRS, before surgery, and at last follow-up, respectively (mean follow-up, 6.9 years). Fifteen AVMs were cured after surgery. Ten patients had good outcomes at last follow-up (7 with mRS Score 0 or 1, and 3 with mRS Score 2). There were 2 deaths (both mRS Score 1 before treatment) and 4 patients with mRS Score 3 outcome (from mRS Scores 0, 1, and 2 [n = 2]).

Conclusions Volume-staged SRS can downgrade AVMs, transforming high-grade AVMs (initially considered inoperable) into operable AVMs with acceptable surgical risks. This treatment paradigm offers an alternative to conservative observation for young patients with unruptured AVMs and long life expectancy, where the risk of hemorrhage is substantial. Difficult AVMs were cured in 15 patients. Surgical morbidity associated with downgraded AVMs is reduced to that of postradiosurgical/preoperative supplemented Spetzler-Martin grades, not their initial AVM grades.

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Effects of Hematoma Reduction by Stereotactic Aspiration for Patients With Spontaneous Intracerebral Hemorrhage

Effects of Hematoma Reduction by Stereotactic Aspiration for Patients With Spontaneous Intracerebral Hemorrhage

Neurosurg Q 2015;25:17–23

Spontaneous intracerebral hemorrhage (ICH) is a devastating medical condition associated with significant morbidity and mortality. Whether the hematoma should be surgically removed remains controversial. This study was a retrospective analysis of patients with spontaneous ICH who were treated with computed tomography (CT)-guided stereotactic aspiration. The aim of this study was to investigate whether hematoma volume reduction in deep-seated ICH utilizing this minimally invasive surgical procedure improves clinical outcome.

Methods: Ninety-nine patients who suffered spontaneous ICH provided informed consent and were included in the study. Patients were divided into an operated group that underwent CT-guided stereotactic aspiration, and a nonoperated group that received only medical treatment. CT-guided stereotactic aspiration was performed at least 8 hours after onset of ICH. Using the Leksell stereotactic frame for guidance, a 4-mm-diameter catheter was inserted into the body of the hematoma through a frontal burr hole. Glasgow Coma Scale, motor function, and length of hospital stay were used to assess differences in outcomes between the 2 groups. The correlation between clinical outcome and stereotactic aspiration was evaluated using multivariate regression analysis.

Results: Ninety-nine consecutive patients were entered into this study. Patients in the operated group (n=41) were treated with CT-guided stereotactic hematoma aspiration. The 3-month Glasgow Outcome Scale score in the nonoperated group (n=58) was significantly lower than that in the operated group (2.32±1.26 vs. 3.15±1.33, P<0.001). Patients in the operated group experienced greater motor function recovery than those in the nonoperated group. The average length of hospital stay of the operated group was significantly shorter than that of the nonoperated group (31.2±14.6 vs. 41.7±17.2 d, P=0.002).

Conclusions: Stereotactic aspiration may improve the functional outcome and shorten the hospital stay of patients who have suffered spontaneous ICH. This procedure is minimally invasive and shows promise as a safe and effective treatment method for these patients.

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Incidence and Clinical Implications of Carotid Branch Occlusion Following Treatment of Internal Carotid Artery Aneurysms With the Pipeline Embolization Device

Incidence and Clinical Implications of Carotid Branch Occlusion Following Treatment of Internal Carotid Artery Aneurysms With the Pipeline Embolization Device

Neurosurgery 76:173–178, 2015

The use of flow diverters such as the pipeline embolization device (PED) for treatment of intracranial aneurysms carries the risk of side branch occlusion.

OBJECTIVE: To determine the incidence and clinical outcomes associated with supraclinoid internal carotid artery (ICA) branch occlusion after deployment of PEDs for ICA aneurysms.

METHODS: We reviewed patients who underwent endovascular treatment with PEDs for ICA aneurysms between June 2011 and March 2013. Forty-nine patients (43 women, mean age 56.36 1.8 years, 68 aneurysms) in whom PEDs traversed the origin of supraclinoid ICA branches (ophthalmic [OA], posterior communicating [PcommA], and anterior choroidal artery [AChA]) were selected for this study. Follow-up angiograms (mean follow-up, 12.8 6 0.8 months) were studied to determine the location of PEDs and the patency of ICA branches.

RESULTS: PEDs were placed across the ostia of 49 OAs, 14 PcommAs, and 11 AChAs. Multiple PEDs were deployed in 16 patients. Rate of branch occlusion was 4% (2/49) for the OA, 7.1% (1/14) for the PcommA, and 0% for the AChA. Patients with branch occlusion did not endure new neurological deficits. ICA branch occlusion was not associated with the number of PEDs covering the ostia (P = .76) or the origin of ICA branches from the aneurysm (P = .24).

CONCLUSION: The incidence of major supraclinoid ICA branch occlusion after treatment with PEDs was low. These events were not associated with new neurological deficits nor were they related to the number of PEDs deployed or the origin of ICA branches from the aneurysm.

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Endovascular Treatment of 346 Middle Cerebral Artery Aneurysms

MCA aneurysmNeurosurgery 76:54–61, 2015

The endovascular treatment of middle cerebral artery (MCA) aneurysms has been controversial because of the frequency of complex anatomy and the relative ease of surgical clipping in this location.

OBJECTIVE: To present a large single-center experience with the endovascular treatment of MCA aneurysms.

METHODS: The neurointerventional database at our institution was reviewed for all endovascular treatments of MCA aneurysms. Demographics, aneurysm characteristics, treatment modality, intraprocedural hemorrhagic and thromboembolic events, 30-day neurological events, and follow-up angiographic studies were recorded.

RESULTS: From December 1996 to April 2013, 292 patients underwent endovascular treatment of 346 MCA aneurysms. Of these, 341 (98.6%) were successfully completed. Balloon neck remodeling was used in 230 procedures (66.5%). Ninety-five procedures (27.4%) were for ruptured aneurysms. The rate of intraprocedural hemorrhage was 2.6% (9 of 346). The overall rate of intraprocedural thromboembolic events was 13.6% (47 of 346), significantly more common in patients with acute subarachnoid hemorrhage (27.4%; P, .001). The 30-day major (modified Rankin Scale score . 2) neurological event rate was 2.9% (10 of 346), significantly more common in patients with subarachnoid hemorrhage (8.4%) compared with those without (0.8%; P , .001). The rate of complete or near-complete aneurysm occlusion at was 90.6% $ 6 months and 91.8% at $ 2 years, with an average of 24 months of follow-up available for 247 procedures.

CONCLUSION: Endovascular treatment of MCA aneurysms can be safe and effective. However, it is associated with a high asymptomatic thromboembolic event rate that is more frequent in the setting of acute subarachnoid hemorrhage.

KEY WORDS:

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Management of complex intracranial aneurysms with bypass surgery


 Complex aneurysms bypass surgery_93 patients

Neurosurg Rev (2015) 38:109–120

Despite advances in microsurgery and the development of new endovascular techniques, the treatment of complex intracranial aneurysms remains a daunting challenge for neurosurgeons. In the present study, we retrospectively reviewed our experience of bypass surgery in the treatment of 93 cases of complex intracranial aneurysms.

A series of 93 consecutive cases of complex intracranial aneurysms were treated with bypass surgery between April 2004 and July 2013. Radial artery (RA) grafts were used in 58 cases, saphenous vein (SV) grafts in 16 cases, and occipital artery (OA) grafts in 6 cases, while the remaining 13 cases were managed with superficial temporal artery (STA) grafts. In this series, the aneurysms were excised after trapping in 32 cases with mass effect and neural compression. Proximal occlusion of the parent artery was performed in 22 cases of fusiform or giant dissecting aneurysms with subsequent retrograde flow to avoid compromise of the perforators nearby. Trapping was performed after bypass surgery in the remaining 39 cases. Postoperative angiographies were performed in 91 patients and patency of the bypass graft and obliteration of the aneurysms were confirmed in 89 patients. Patency of the bypass could not be confirmed in the remaining two patients, of which one presented with cerebral infarction due to graft occlusion, and the other remained asymptomatic. Within 1 month after surgery, 88 patients had good outcome, four patients needed assistance for daily living, and one death occurred due to brainstem infarction. In 77 patients with a mean follow-up of 3.0 years, 72 patients had good outcome, 4 patients needed assistance for daily living, and 1 death occurred unrelated to surgery.

Complex intracranial aneurysms present unique therapeutic challenges that require thorough surgical planning, individualized treatment strategies, and refined neurovascular techniques for successful outcome. Proper use of bypass surgery is imperative in preserving the parent artery and its major perforators. The internal maxillary artery, used as a donor in a bypass, is an effective method due to its shorter distance from the recipient vessels and relatively large diameter with resulting higher flow rate.

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