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Arias EJ, Vajapey S, Reynolds MR, Chicoine MR, Rich KM, Dacey RG, Dorward IG, Derdeyn CP, Moran CJ, Cross DT, Zipfel GJ, Dhar R. Utility of Screening for Cerebral Vasospasm Using Digital Subtraction Angiography. Stroke 2015; 46:3137-41. [PMID: 26405204 DOI: 10.1161/strokeaha.115.010081] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 08/06/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Cerebral arterial vasospasm (CVS) is a common complication of aneurysmal subarachnoid hemorrhage strongly associated with neurological deterioration and delayed cerebral ischemia (DCI). The utility of screening for CVS as a surrogate for early detection of DCI, especially in patients without clinical signs of DCI, remains uncertain. METHODS We performed a retrospective analysis of 116 aneurysmal subarachnoid hemorrhage patients who underwent screening digital subtraction angiography to determine the association of significant CVS and subsequent development of DCI. Patients were stratified into 3 groups: (1) no symptoms of DCI before screening, (2) ≥1 episodes of suspected DCI symptoms before screening, and (3) unable to detect symptoms because of poor examination. RESULTS Patients asymptomatic before screening had significantly lower rates of CVS (18%) compared with those with transient symptoms of DCI (60%; P<0.0001). None of the 79 asymptomatic patients developed DCI after screening, regardless of digital subtraction angiography findings, compared with 56% of those with symptoms (P<0.0001). Presence of CVS was significantly associated with DCI in those with transient symptoms and in those whose examinations did not permit clear assessment (odds ratio 16.0, 95% confidence interval 2.2-118.3, P=0.003). CONCLUSIONS Patients asymptomatic before screening have low rates of CVS and seem to be at negligible risk of developing DCI. Routine screening of asymptomatic patients seems to have little utility. Screening may still be considered in patients with possible symptoms of DCI or those with examinations too poor to clinically detect symptoms because finding CVS may be useful for risk stratification and guiding management.
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Greenberg JK, Washington CW, Guniganti R, Dacey RG, Derdeyn CP, Zipfel GJ. Causes of 30-day readmission after aneurysmal subarachnoid hemorrhage. J Neurosurg 2015; 124:743-9. [PMID: 26361278 DOI: 10.3171/2015.2.jns142771] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Hospital readmission is a common but controversial quality measure increasingly used to influence hospital compensation in the US. The objective of this study was to evaluate the causes for 30-day hospital readmission following aneurysmal subarachnoid hemorrhage (SAH) to determine the appropriateness of this performance metric and to identify potential avenues for improved patient care. METHODS The authors retrospectively reviewed the medical records of all patients who received surgical or endovascular treatment for aneurysmal SAH at Barnes-Jewish Hospital between 2003 and 2013. Two senior faculty identified by consensus the primary medical/surgical diagnosis associated with readmission as well as the underlying causes of rehospitalization. RESULTS Among 778 patients treated for aneurysmal SAH, 89 experienced a total of 97 readmission events, yielding a readmission rate of 11.4%. The median time from discharge to readmission was 9 days (interquartile range 3-17.5 days). Actual hydrocephalus or potential concern for hydrocephalus (e.g., headache) was the most frequent diagnosis (26/97, 26.8%), followed by infections (e.g., wound infection [5/97, 5.2%], urinary tract infection [3/97, 3.1%], and pneumonia [3/97, 3.1%]) and thromboembolic events (8/97, 8.2%). In most cases (75/97, 77.3%), we did not identify any treatment lapses contributing to readmission. The most common underlying causes for readmission were unavoidable development of SAH-related pathology (e.g., hydrocephalus; 36/97, 37.1%) and complications related to neurological impairment and immobility (e.g., thromboembolic event despite high-dose chemoprophylaxis; 21/97, 21.6%). The authors determined that 22/97 (22.7%) of the readmissions were likely preventable with alternative management. In these cases, insufficient outpatient medical care (for example, for hyponatremia; 16/97, 16.5%) was the most common shortcoming. CONCLUSIONS Most readmissions after aneurysmal SAH relate to late consequences of hemorrhage, such as hydrocephalus, or medical complications secondary to severe neurological injury. Although a minority of readmissions may potentially be avoided with closer medical follow-up in the transitional care environment, readmission after SAH is an insensitive and likely inappropriate hospital performance metric.
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Washington CW, Derdeyn CP, Dhar R, Arias EJ, Chicoine MR, Cross DT, Dacey RG, Han BH, Moran CJ, Rich KM, Vellimana AK, Zipfel GJ. A Phase I proof-of-concept and safety trial of sildenafil to treat cerebral vasospasm following subarachnoid hemorrhage. J Neurosurg 2015; 124:318-27. [PMID: 26314998 DOI: 10.3171/2015.2.jns142752] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Studies show that phosphodiesterase-V (PDE-V) inhibition reduces cerebral vasospasm (CVS) and improves outcomes after experimental subarachnoid hemorrhage (SAH). This study was performed to investigate the safety and effect of sildenafil (an FDA-approved PDE-V inhibitor) on angiographic CVS in SAH patients. METHODS A2-phase, prospective, nonrandomized, human trial was implemented. Subarachnoid hemorrhage patients underwent angiography on Day 7 to assess for CVS. Those with CVS were given 10 mg of intravenous sildenafil in the first phase of the study and 30 mg in the second phase. In both, angiography was repeated 30 minutes after infusion. Safety was assessed by monitoring neurological examination findings and vital signs and for the development of adverse reactions. For angiographic assessment, in a blinded fashion, pre- and post-sildenafil images were graded as "improvement" or "no improvement" in CVS. Unblinded measurements were made between pre- and post-sildenafil angiograms. RESULTS Twelve patients received sildenafil; 5 patients received 10 mg and 7 received 30 mg. There were no adverse reactions. There was no adverse effect on heart rate or intracranial pressure. Sildenafil resulted in a transient decline in mean arterial pressure, an average of 17% with a return to baseline in an average of 18 minutes. Eight patients (67%) were found to have a positive angiographic response to sildenafil, 3 (60%) in the low-dose group and 5 (71%) in the high-dose group. The largest degree of vessel dilation was an average of 0.8 mm (range 0-2.1 mm). This corresponded to an average percentage increase in vessel diameter of 62% (range 0%-200%). CONCLUSIONS The results from this Phase I safety and proof-of-concept trial assessing the use of intravenous sildenafil in patients with CVS show that sildenafil is safe and well tolerated in the setting of SAH. Furthermore, the angiographic data suggest that sildenafil has a positive impact on human CVS.
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Madaelil TP, Wallace AN, Chatterjee AN, Zipfel GJ, Dacey RG, Cross DT, Moran CJ, Derdeyn CP. Endovascular parent vessel sacrifice in ruptured dissecting vertebral and posterior inferior cerebellar artery aneurysms: clinical outcomes and review of the literature. J Neurointerv Surg 2015; 8:796-801. [DOI: 10.1136/neurintsurg-2015-011732] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 07/06/2015] [Indexed: 11/04/2022]
Abstract
BackgroundRuptured intracranial dissecting aneurysms must be secured quickly to prevent re-hemorrhage. Endovascular sacrifice of the diseased segment is a well-established treatment method, however postoperative outcomes of symptomatic stroke and re-hemorrhage rates are not well reported, particularly for the perforator-rich distal vertebral artery or proximal posterior inferior cerebellar artery (PICA).MethodsWe retrospectively reviewed cases of ruptured distal vertebral artery or PICA dissecting aneurysms that underwent endovascular treatment. Diagnosis was based on the presence of subarachnoid hemorrhage on initial CT imaging and of a dissecting aneurysm on catheter angiography. Patients with vertebral artery aneurysms were selected for coil embolization of the diseased arterial segment based on the adequacy of flow to the basilar artery from the contralateral vertebral artery. Patients with PICA aneurysms were generally treated only if they were poor surgical candidates. Outcomes included symptomatic and asymptomatic procedure-related cerebral infarction, recurrent aneurysm rupture, angiographic aneurysm recurrence, and estimated modified Rankin Scale (mRS).ResultsDuring the study period, 12 patients with dissecting aneurysms involving the distal vertebral artery (n=10) or PICA (n=2) were treated with endovascular sacrifice. Two patients suffered an ischemic infarction, one of whom was symptomatic (8.3%). One patient (8.3%) died prior to hospital discharge. No aneurysm recurrence was identified on follow-up imaging. Ten patients (83%) made a good recovery (mRS ≤2). Median clinical and imaging follow-up periods were 41.7 months (range 0–126.4 months) and 14.3 months (range 0.03–88.6 months), respectively.ConclusionsIn patients with good collateral circulation, endovascular sacrifice may be the preferred treatment for acutely ruptured dissecting aneurysms involving the distal vertebral artery.
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Sun SQ, Kim AH, Cai C, Murphy RKJ, DeWees T, Sylvester P, Dacey RG, Grubb RL, Rich KM, Zipfel GJ, Dowling JL, Leuthardt EC, Leonard JR, Evans J, Simpson JR, Robinson CG, Perrin RJ, Huang J, Chicoine MR. Management of atypical cranial meningiomas, part 1: predictors of recurrence and the role of adjuvant radiation after gross total resection. Neurosurgery 2015; 75:347-54; discussion 354-5; quiz 355. [PMID: 24932707 DOI: 10.1227/neu.0000000000000461] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Indications for external beam radiation therapy (EBRT) for atypical meningiomas (AMs) remain unclear. OBJECTIVE To analyze features associated with recurrence in AM patients after gross total resection (GTR) and to assess the relative benefit of EBRT in a retrospective cohort study. METHODS One hundred fifty-one primary AMs after GTR (88 female patients; median follow-up, 45.0 months) were examined for possible predictors of recurrence (age, sex, location, volume, bone involvement, brain invasion). The Fisher exact and Wilcoxon rank-sum tests were used to analyze the association between these predictors and use of EBRT. The impact on recurrence for these predictors and EBRT was analyzed with Kaplan-Meier and Cox regression. RESULTS Of 151 patients, 13 (8.6%) experienced recurrence after GTR (median, 47.0 months). Multivariate analysis identified elevated mitotic index (P = .007) and brain invasion (P = .002) as predictors of recurrence. Larger volume (P = .96) was not associated with recurrence but was more likely to prompt EBRT (P = .001). Recurrences occurred in 11 of 112 with GTR (9.8%; median, 44 months) and 2 of 39 with GTR/EBRT (5.1%; median, 133 months). The 2-, 5-, and 10-year progression-free survival rates after GTR vs GTR/EBRT were 97%, 86%, and 68% vs 100%, 100%, and 78%. Kaplan-Meier analysis demonstrated no difference in progression-free survival or overall survival after GTR vs GTR/EBRT (P = .8, P > .99). CONCLUSION Brain invasion and high mitotic rates may predict recurrence. After GTR of AMs, EBRT appears not to affect progression-free survival and overall survival, suggesting that observation rather than EBRT may be indicated after GTR.
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Reynolds MR, Roland JL, Kamath AA, Cross DT, Dacey RG. Microsurgical confirmation of perforating arteries arising from the fundus of a posterior communicating artery aneurysm. Neurosurg Focus 2015; 39 Video Suppl 1:V16. [PMID: 26132614 DOI: 10.3171/2015.7.focusvid.14628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Perforating arteries rarely project from the fundus of an aneurysm. We present the case of a 35-year-old woman who was found to have a right posterior communicating artery (PCOM) aneurysm via catheter angiography. Superselective microcatheter angiography revealed that perforating arteries arose from the aneurysm fundus that supplied the anterolateral thalamus. Microsurgical exploration confirmed several small perforating arteries arising from the aneurysm dome as well as an atretic distal PCOM artery. Given the complex anatomy, the lesion was unsuitable for clipping. We propose that this aneurysm represents a developmental variant whereby the proximal PCOM artery becomes atretic and terminates in PCOM perforators. The video can be found here: http://youtu.be/iDcp9fsDjq4.
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Mao DD, Gujar AD, Mahlokozera T, Chen I, Pan Y, Luo J, Brost T, Thompson EA, Turski A, Leuthardt EC, Dunn GP, Chicoine MR, Rich KM, Dowling JL, Zipfel GJ, Dacey RG, Achilefu S, Tran DD, Yano H, Kim AH. A CDC20-APC/SOX2 Signaling Axis Regulates Human Glioblastoma Stem-like Cells. Cell Rep 2015; 11:1809-21. [PMID: 26074073 DOI: 10.1016/j.celrep.2015.05.027] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 02/28/2015] [Accepted: 05/12/2015] [Indexed: 11/29/2022] Open
Abstract
Glioblastoma harbors a dynamic subpopulation of glioblastoma stem-like cells (GSCs) that can propagate tumors in vivo and is resistant to standard chemoradiation. Identification of the cell-intrinsic mechanisms governing this clinically important cell state may lead to the discovery of therapeutic strategies for this challenging malignancy. Here, we demonstrate that the mitotic E3 ubiquitin ligase CDC20-anaphase-promoting complex (CDC20-APC) drives invasiveness and self-renewal in patient tumor-derived GSCs. Moreover, CDC20 knockdown inhibited and CDC20 overexpression increased the ability of human GSCs to generate brain tumors in an orthotopic xenograft model in vivo. CDC20-APC control of GSC invasion and self-renewal operates through pluripotency-related transcription factor SOX2. Our results identify a CDC20-APC/SOX2 signaling axis that controls key biological properties of GSCs, with implications for CDC20-APC-targeted strategies in the treatment of glioblastoma.
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Arias EJ, Dunn GP, Washington CW, Derdeyn CP, Chicoine MR, Grubb RL, Moran CJ, Cross DT, Dacey RG, Zipfel GJ. Surgical Revascularization in North American Adults with Moyamoya Phenomenon: Long-Term Angiographic Follow-up. J Stroke Cerebrovasc Dis 2015; 24:1597-608. [PMID: 25972283 DOI: 10.1016/j.jstrokecerebrovasdis.2015.03.053] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 02/18/2015] [Accepted: 03/18/2015] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND North American and Asian forms of moyamoya have distinct clinical characteristics. Asian adults with moyamoya are known to respond better to direct versus indirect revascularization. It is unclear whether North American adults with moyamoya have a similar long-term angiographic response to direct versus indirect bypass. METHODS A retrospective review of surgical revascularization for adult moyamoya phenomenon was performed. Preoperative and postoperative cerebral angiograms underwent consensus review, with degree of revascularization quantified as extent of new middle cerebral artery (MCA) territory filling. RESULTS Late angiographic follow-up was available in 15 symptomatic patients who underwent 20 surgical revascularization procedures. In 10 hemispheres treated solely with indirect arterial bypass, 3 had 2/3 revascularization, 4 had 1/3 revascularization, and 3 had no revascularization of the MCA territory. In the 10 hemispheres treated with direct arterial bypass (8 as a stand-alone procedure and 2 in combination with an indirect procedure), 2 had complete revascularization, 7 had 2/3 revascularization, and 1 had 1/3 revascularization. Direct bypass provided a higher rate of "good" angiographic outcome (complete or 2/3 revascularization) when compared with indirect techniques (P = .0198). CONCLUSIONS Direct bypass provides a statistically significant, more consistent, and complete cerebral revascularization than indirect techniques in this patient population. This is similar to that reported in the Asian literature, which suggests that the manner of presentation (ischemia in North American adults versus hemorrhage in Asian adults) is likely not a contributor to the extent of revascularization achieved after surgical intervention.
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Sun SQ, Cai C, Ravindra VM, Gamble P, Yarbrough CK, Dacey RG, Dowling JL, Zipfel GJ, Wright NM, Santiago P, Robinson CG, Schmidt MH, Kim AH, Ray WZ. Simpson Grade I-III Resection of Spinal Atypical (World Health Organization Grade II) Meningiomas is Associated With Symptom Resolution and Low Recurrence. Neurosurgery 2015; 76:739-46. [DOI: 10.1227/neu.0000000000000720] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
BACKGROUND:
Because of their rarity, outcomes regarding spinal atypical meningiomas (AMs) remain unclear.
OBJECTIVE:
To describe the recurrence rate and postoperative outcomes after resection of spinal AMs, and to discuss an appropriate resection strategy and adjuvant therapy for spinal AMs.
METHODS:
Data from all patients who presented with spinal AMs to 2 tertiary referral centers between 1998 and 2013 were obtained by chart review.
RESULTS:
From 102 patients with spinal meningioma, 20 AM tumors (7 cervical, 11 thoracic, 2 thoracolumbar) were identified in 18 patients (median age, 50 years [range, 19-75] at time of resection; 11% male; median follow-up, 32 months [range, 1-179] after resection). Before resection, patients had sensory deficits (70%), pain (70%), weakness (60%), ataxia (50%), spasticity (65%), and incontinence (35%). One tumor presented asymptomatically. Simpson grade I, II, III, and IV resection were achieved in 3 (15%), 13 (65%), 2 (10%), and 2 (10%) tumors, respectively. One patient that underwent Simpson grade III resection received adjuvant radiation therapy. After Simpson grade I-III or gross total resection, no tumors recurred (0%; confidence interval, 0%-17.6%). After Simpson grade IV resection, 1 tumor recurred (50%; confidence interval, 1.3%-98.7%). With the exception of 1 patient who had bilateral paraplegia perioperatively, all other patients experienced improvement of preoperative symptoms after surgery (median time, 3.6 months [range, 1-13] after resection).
CONCLUSION:
Despite published cases suggesting an aggressive clinical course for spinal AMs, this series of spinal AMs reports that gross total resection without adjuvant radiation therapy resulted in symptom resolution and low recurrence.
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Speirs CK, Simpson JR, Robinson CG, DeWees TA, Tran DD, Linette G, Chicoine MR, Dacey RG, Rich KM, Dowling JL, Leuthardt EC, Zipfel GJ, Kim AH, Huang J. Impact of 1p/19q Codeletion and Histology on Outcomes of Anaplastic Gliomas Treated With Radiation Therapy and Temozolomide. Int J Radiat Oncol Biol Phys 2015; 91:268-76. [DOI: 10.1016/j.ijrobp.2014.10.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 09/03/2014] [Accepted: 10/14/2014] [Indexed: 12/25/2022]
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Sylvester PT, Evans JA, Zipfel GJ, Chole RA, Uppaluri R, Haughey BH, Getz AE, Silverstein J, Rich KM, Kim AH, Dacey RG, Chicoine MR. Combined high-field intraoperative magnetic resonance imaging and endoscopy increase extent of resection and progression-free survival for pituitary adenomas. Pituitary 2015; 18:72-85. [PMID: 24599833 PMCID: PMC4161669 DOI: 10.1007/s11102-014-0560-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
PURPOSE The clinical benefit of combined intraoperative magnetic resonance imaging (iMRI) and endoscopy for transsphenoidal pituitary adenoma resection has not been completely characterized. This study assessed the impact of microscopy, endoscopy, and/or iMRI on progression-free survival, extent of resection status (gross-, near-, and sub-total resection), and operative complications. METHODS Retrospective analyses were performed on 446 transsphenoidal pituitary adenoma surgeries at a single institution between 1998 and 2012. Multivariate analyses were used to control for baseline characteristics, differences during extent of resection status, and progression-free survival analysis. RESULTS Additional surgery was performed after iMRI in 56/156 cases (35.9%), which led to increased extent of resection status in 15/156 cases (9.6%). Multivariate ordinal logistic regression revealed no increase in extent of resection status following iMRI or endoscopy alone; however, combining these modalities increased extent of resection status (odds ratio 2.05, 95% CI 1.21-3.46) compared to conventional transsphenoidal microsurgery. Multivariate Cox regression revealed that reduced extent of resection status shortened progression-free survival for near- versus gross-total resection [hazard ratio (HR) 2.87, 95% CI 1.24-6.65] and sub- versus near-total resection (HR 2.10; 95% CI 1.00-4.40). Complication comparisons between microscopy, endoscopy, and iMRI revealed increased perioperative deaths for endoscopy versus microscopy (4/209 and 0/237, respectively), but this difference was non-significant considering multiple post hoc comparisons (Fisher exact, p = 0.24). CONCLUSIONS Combined use of endoscopy and iMRI increased pituitary adenoma extent of resection status compared to conventional transsphenoidal microsurgery, and increased extent of resection status was associated with longer progression-free survival. Treatment modality combination did not significantly impact complication rate.
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Hawasli AH, Chicoine MR, Dacey RG. Choosing Wisely: a neurosurgical perspective on neuroimaging for headaches. Neurosurgery 2015; 76:1-5; quiz 6. [PMID: 25255253 PMCID: PMC4861636 DOI: 10.1227/neu.0000000000000560] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Multiple national initiatives seek to curb spending to address increasing healthcare costs in the United States. The Choosing Wisely initiative is a popular initiative that focuses on reducing healthcare spending by setting guidelines to limit tests and procedures requested by patients and ordered by physicians. To reduce spending on neuroimaging, the Choosing Wisely initiative and other organizations have offered guidelines to limit neuroimaging for headaches. Although the intentions are laudable, these guidelines are inconsistent with the neurosurgeon's experience with patients with brain tumor. If adopted by governing or funding organizations, these guidelines threaten to negatively affect the care and outcomes of patients with brain tumors, who frequently present with minimal symptoms or isolated headaches syndromes. As physicians grapple with the difficult conflict between evidence-based cost-cutting guidelines and individualized patient-tailored medicine, they must carefully balance the costs and benefits of discretionary services such as neuroimaging for headaches. By participating in the development of validated clinical decision rules on neuroimaging for headaches, neurosurgeons can advocate for their patients and improve their patients' outcomes.
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Washington CW, Derdeyn CP, Chicoine MR, Cross DT, Dacey RG, Moran CJ, Rich KM, Zipfel GJ. Comparing routine versus selective use of intraoperative cerebral angiography in aneurysm surgery: a prospective study. J Neurointerv Surg 2014; 8:75-80. [PMID: 25423951 DOI: 10.1136/neurintsurg-2014-011515] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 11/09/2014] [Indexed: 11/04/2022]
Abstract
INTRODUCTION While the use of intraoperative angiography (IA) has been shown to be a useful adjunct in aneurysm surgery, its routine use remains controversial. OBJECTIVE We wished to determine if IA is required in all patients undergoing aneurysm surgery (ie, routine IA) or if intraoperative assessment can reliably predict the need for IA (ie, select IA). METHODS We prospectively evaluated all patients undergoing craniotomy for aneurysm clipping. In these patients, the treating surgeons were asked to record whether they felt IA was required at two time points: (1) prior to surgery and (2) immediately after clip application but before IA. All patients underwent IA as per the institutional protocol. IA results and the need for post-IA clip adjustments were recorded. RESULTS Of the 200 patients enrolled, 197 were included for analysis. IA was deemed necessary on preoperative assessment in 144 cases (73%) and on post-clip assessment in 116 cases (59%). Post-clip IA demonstrated 47 (24%) positive findings and post-IA clip adjustments were made in 19 of 198 cases (10%). On preoperative assessment, there were four cases where IA was deemed unnecessary, yet post-IA clip adjustment was required, resulting in a sensitivity of 79% and false negative rate of 8%. Regarding post-clip assessment, there were five cases where IA was thought to be unnecessary and clip adjustment was required, resulting in a sensitivity of 73% and false negative rate of 6%. CONCLUSIONS The accuracy of a strategy of select IA was not improved by assessing the need for IA immediately after aneurysm clipping versus prior to surgery onset. This suggests that intraoperative assessment regarding the adequacy of aneurysm clip application should be viewed with caution.
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Arias EJ, Patel B, Cross DT, Moran CJ, Dacey RG, Zipfel GJ, Derdeyn CP. Timing and nature of in-house postoperative events following uncomplicated elective endovascular aneurysm treatment. J Neurosurg 2014; 121:1063-70. [DOI: 10.3171/2014.7.jns132676] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Most patients with asymptomatic intracranial aneurysms treated with endovascular methods are closely observed overnight in an intensive care unit setting for complications, including ischemic and hemorrhagic stroke, cardiac dysfunction, and groin access complications. The purpose of this study was to analyze the timing, nature, and rate of in-house postoperative events.
Methods
Patients who underwent endovascular treatment or retreatment of unruptured cerebral aneurysms from March 2002 to June 2012 were identified from a prospective case log and their medical records were reviewed. The presentation, patient characteristics, aneurysm size and location, and method of endovascular treatment of each cerebral aneurysm were recorded. Patients with adverse intraprocedural events including perforation and thromboembolism were excluded from this analysis. Overnight postprocedural monitoring was performed in a neurological intensive care unit or postanesthesia care unit for all patients, with discharge planned for postoperative Day 1. Postprocedural events occurring during hospitalization were categorized as intracranial hemorrhage, ischemic stroke, groin hematoma resulting in additional treatment or prolonged hospital stay, retroperitoneal hematoma, and cardiac events. The time from the completion of the procedure to event discovery was recorded.
Results
A total of 687 endovascular treatments of unruptured cerebral aneurysms were performed. Nine treatments were excluded from our analysis due to intraprocedural events. Endovascular procedures included coiling alone, stent-assisted coiling, balloon-assisted coiling, balloon-assisted embolization with a liquid embolic agent, and placement of a flow diversion device with or without coiling. Twenty-seven treatments (4.0%) resulted in postprocedural complications: 3 intracranial hemorrhages, 6 ischemic strokes, 4 cardiac events, 5 retroperitoneal hematomas, and 9 groin hematomas. The majority (20 [74.0%]) of these 27 complications were detected within 4 hours from the procedure. These included 1 hemorrhage, 4 ischemic strokes, 4 cardiac events, 2 retroperitoneal hematomas, and 9 groin hematomas. All cardiac events and groin hematomas were detected within 4 hours. Four (14%) of the 27 complications were detected between 4 and 12 hours, 1 (3.7%) between 12 and 24 hours, and 2 (7.4%) more than 24 hours after the procedure. The complications detected more than 4 hours from the conclusion of the procedure included 2 minor intracranial hemorrhages causing headache and resulting in no permanent deficits, 2 mild ischemic strokes, and 3 asymptomatic retroperitoneal hematomas identified by falling hematocrit levels that required no further intervention or treatment.
Conclusions
The large majority of significant postprocedural events after uncomplicated endovascular aneurysm intervention occur within the first 4 hours; these events become less frequent with increasing time. Transfer to a floor bed after 4–12 hours for further observation is reasonable to consider in some patients.
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Dacey RG. Editorial: Our continuing experience with duty-hours regulation and its effect on quality of care and education. J Neurosurg Spine 2014; 21:499-501. [DOI: 10.3171/2014.1.spine131102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Arias EJ, Derdeyn CP, Dacey RG, Zipfel GJ. Advances and surgical considerations in the treatment of moyamoya disease. Neurosurgery 2014; 74 Suppl 1:S116-25. [PMID: 24402480 DOI: 10.1227/neu.0000000000000229] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Moyamoya is a rare disorder that involves steno-occlusive arterial changes of the anterior circulation, along with proliferative development of basal arterial collaterals. It is either idiopathic (called moyamoya disease) or the result of a specific underlying condition such as atherosclerosis, radiation therapy, or sickle cell disease (called moyamoya syndrome or phenomenon). In recent years, numerous insights into and advances in the understanding, evaluation, and management of moyamoya patients have occurred. This article briefly reviews the spectrum of moyamoya conditions and then provides a synopsis of numerous recent investigations that shed light on various aspects of the disease, including its clinical characteristics, natural history, underlying pathology, imaging, surgical techniques, and long-term patient outcome.
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Washington CW, Derdeyn CP, Dacey RG, Dhar R, Zipfel GJ. Analysis of subarachnoid hemorrhage using the Nationwide Inpatient Sample: the NIS-SAH Severity Score and Outcome Measure. J Neurosurg 2014; 121:482-9. [DOI: 10.3171/2014.4.jns131100] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Studies using the Nationwide Inpatient Sample (NIS), a large ICD-9–based (International Classification of Diseases, Ninth Revision) administrative database, to analyze aneurysmal subarachnoid hemorrhage (SAH) have been limited by an inability to control for SAH severity and the use of unverified outcome measures. To address these limitations, the authors developed and validated a surrogate marker for SAH severity, the NIS-SAH Severity Score (NIS-SSS; akin to Hunt and Hess [HH] grade), and a dichotomous measure of SAH outcome, the NIS-SAH Outcome Measure (NIS-SOM; akin to modified Rankin Scale [mRS] score).
Methods
Three separate and distinct patient cohorts were used to define and then validate the NIS-SSS and NIS-SOM. A cohort (n = 148,958, the “model population”) derived from the 1998–2009 NIS was used for developing the NIS-SSS and NIS-SOM models. Diagnoses most likely reflective of SAH severity were entered into a regression model predicting poor outcome; model coefficients of significant factors were used to generate the NIS-SSS. Nationwide Inpatient Sample codes most likely to reflect a poor outcome (for example, discharge disposition, tracheostomy) were used to create the NIS-SOM.
Data from 716 patients with SAH (the “validation population”) treated at the authors' institution were used to validate the NIS-SSS and NIS-SOM against HH grade and mRS score, respectively.
Lastly, 147,395 patients (the “assessment population”) from the 1998–2009 NIS, independent of the model population, were used to assess performance of the NIS-SSS in predicting outcome. The ability of the NIS-SSS to predict outcome was compared with other common measures of disease severity (All Patient Refined Diagnosis Related Group [APR-DRG], All Payer Severity-adjusted DRG [APS-DRG], and DRG).
Results
The NIS-SSS significantly correlated with HH grade, and there was no statistical difference between the abilities of the NIS-SSS and HH grade to predict mRS-based outcomes. As compared with the APR-DRG, APSDRG, and DRG, the NIS-SSS was more accurate in predicting SAH outcome (area under the curve [AUC] = 0.69, 0.71, 0.71, and 0.79, respectively).
A strong correlation between NIS-SOM and mRS was found, with an agreement and kappa statistic of 85% and 0.63, respectively, when poor outcome was defined by an mRS score > 2 and 95% and 0.84 when poor outcome was defined by an mRS score > 3.
Conclusions
Data in this study indicate that in the analysis of NIS data sets, the NIS-SSS is a valid measure of SAH severity that outperforms previous measures of disease severity and that the NIS-SOM is a valid measure of SAH outcome. It is critically important that outcomes research in SAH using administrative data sets incorporate the NIS-SSS and NIS-SOM to adjust for neurology-specific disease severity.
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68
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Sun SQ, Cai C, Murphy RK, DeWees T, Dacey RG, Grubb RL, Rich KM, Zipfel GJ, Dowling JL, Leuthardt EC, Leonard JR, Evans J, Simpson JR, Robinson CG, Perrin RJ, Huang J, Chicoine MR, Kim AH. Management of Atypical Cranial Meningiomas, Part 2. Neurosurgery 2014; 75:356-63; discussion 363. [DOI: 10.1227/neu.0000000000000462] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Abstract
BACKGROUND:
The efficacies of adjuvant stereotactic radiosurgery (SRS) and external beam radiation therapy (EBRT) for atypical meningiomas (AMs) after subtotal resection (STR) remain unclear.
OBJECTIVE:
To analyze the clinical, histopathological, and radiographic features associated with progression in AM patients after STR.
METHODS:
Fifty-nine primary AMs after STR were examined for predictors of progression, including the impact of SRS and EBRT, in a retrospective cohort study.
RESULTS:
Twenty-seven patients (46%) progressed after STR (median, 30 months). On univariate analysis, spontaneous necrosis positively (hazard ratio = 5.2; P = .006) and adjuvant radiation negatively (hazard ratio = 0.3; P = .009) correlated with progression; on multivariate analysis, only adjuvant radiation remained independently significant (hazard ratio = 0.3; P = .006). SRS and EBRT were associated with greater local control (LC; P = .02) and progression-free survival (P = .007). The 2-, 5-, and 10-year actuarial LC rates after STR vs STR/EBRT were 60%, 34%, and 34% vs 96%, 65%, and 45%. The 2-, 5-, and 10-year actuarial progression-free survival rates after STR vs STR/EBRT were 60%, 30%, and 26% vs 96%, 65%, and 45%. Compared with STR alone, adjuvant radiation therapy significantly improved LC in AMs that lack spontaneous necrosis (P = .003) but did not improve LC in AMs with spontaneous necrosis (P = .6).
CONCLUSION:
Adjuvant SRS or EBRT improved LC of AMs after STR but only for tumors without spontaneous necrosis. Spontaneous necrosis may aid in decisions to administer adjuvant SRS or EBRT after STR of AMs.
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69
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Sachdeva AK, Flynn TC, Brigham TP, Dacey RG, Napolitano LM, Bass BL, Philibert I, Blair PG, Lupi LK. Interventions to address challenges associated with the transition from residency training to independent surgical practice. Surgery 2014; 155:867-82. [DOI: 10.1016/j.surg.2013.12.027] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 12/26/2013] [Indexed: 01/22/2023]
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70
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Hawasli AH, Buckley RT, Gao F, Limbrick DD, Smyth MD, Leonard JR, Santiago P, Stewart TJ, Park TS, Grubb RL, Dowling JL, Leuthardt EC, Rich KM, Zipfel GJ, Dacey RG, Chicoine MR. Biopsy of the superficial cortex: predictors of effectiveness and outcomes. Neurosurgery 2014; 73:224-31; discussion 231-2; quiz 232. [PMID: 23632761 DOI: 10.1227/01.neu.0000430310.63702.3e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Brain biopsies of superficial cortex are performed for diagnosis of neurological diseases, but preoperative predictors of successful diagnosis and risks are lacking. OBJECTIVE We evaluated effectiveness and outcomes of superficial cortical biopsies and determined preoperative predictors of diagnosis, outcomes, morbidities, and mortality. METHODS A single-institution retrospective analysis of 170 patients who underwent open brain biopsies of superficial cortex was performed. Clinical predictors of effectiveness and outcomes were determined using univariate/multivariate analyses and a system for risk-benefit stratification was created and tested. RESULTS Brain biopsies led to successful diagnosis in 122 of 170 (71.8%) and affected management in 97 of 170 (57.1%) cases. Factors increasing the odds of diagnostic pathology included age older than 45 years (odds ratio [OR]: 2.67, 95% confidence interval [CI]: 1.34-5.27, P < .01), previous cancer diagnosis (OR: 3.64, 95% CI: 1.69-7.85, P < .001), focal (OR: 3.90, 95% CI: 1.91-8.00, P < .001) and enhancing (OR: 5.03, 95% CI: 2.41-10.52, P < .001) lesions on magnetic resonance imaging, biopsy of specific lesions on magnetic resonance imaging (OR: 9.34, 95% CI: 4.29-20.33, P < .001), and use of intraoperative navigation (OR: 6.59, 95% CI: 3.04-14.28, P < .001). Brain biopsies led to symptomatic intracranial hemorrhage, seizures, other significant morbidities, and perioperative mortality in 12.4%, 16.2%, 37.1%, and 8% of cases, respectively. Risk of postoperative intracranial hemorrhage was increased by a history of aspirin use (OR: 2.51, 95% CI: 1.23-5.28, P < .05) and age older than 60 years (OR: 2.66, 95% CI: 1.36-5.18, P < .01). CONCLUSION Effectiveness and risk of morbidity/mortality can be estimated preoperatively for patients undergoing open brain biopsies of the superficial cortex. Older age and specific imaging characteristics increase the odds of diagnostic biopsy. Conversely, older age and aspirin use increases the risk of postoperative complications.
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71
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Vellimana AK, Yarbrough CK, Blackburn S, Strom RG, Pilgram TK, Lee JM, Grubb RL, Rich KM, Chicoine MR, Dacey RG, Derdeyn CP, Zipfel GJ. Intravenous tissue-type plasminogen activator therapy is an independent risk factor for symptomatic intracerebral hemorrhage after carotid endarterectomy. Neurosurgery 2014; 74:254-61. [PMID: 24335814 PMCID: PMC4097004 DOI: 10.1227/neu.0000000000000261] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Carotid endarterectomy (CEA) for symptomatic carotid artery stenosis and intravenous tissue-type plasminogen activator (IV-tPA) for acute ischemic stroke are proven therapies; however, the safety of CEA in stroke patients who recently received IV-tPA has not been established. OBJECTIVE To evaluate the safety of CEA in stroke patients who recently received IV-tPA. METHODS A retrospective review of patients who underwent CEA for symptomatic carotid artery stenosis was performed. The primary end point was postoperative symptomatic intracerebral hemorrhage (sICH). A univariate analysis of potential risk factors for sICH, including IV-tPA therapy, timing of CEA, degree of stenosis, and stroke severity, was performed. Factors with a value of P < .1 on univariate analysis were tested further. RESULTS Among 142 patients, 3 suffered sICH after CEA: 2 of 11 patients treated with IV-tPA (18.2%) and 1 of 131 patients not treated with IV-tPA (0.8%). Both IV-tPA patients suffering sICH underwent CEA within 3 days of tPA administration. On univariate analysis, IV-tPA (P = .02), female sex (P = .09), shorter time between ischemic event and CEA (P = .06), and lower mean arterial pressure during the first 48 hours of admission (P = .08) were identified as risk factors for sICH. On multivariate analysis, IV-tPA was the only significant risk factor (P = .002 by stepwise logistic regression; P = .03 by nominal logistic regression). CONCLUSION This study indicates that IV-tPA is an independent risk factor for sICH after CEA. This suggests that CEA should be pursued cautiously in patients who recently received IV-tPA. Early surgery may be associated with an increased risk for sICH. ABBREVIATIONS CEA, carotid endarterectomyIV-tPA, intravenous recombinant tissue-type plasminogen activatorMAP, mean arterial pressureNASCET, North American Symptomatic Carotid Endarterectomy TrialNIHSS, National Institutes of Health Stroke ScaleNINDS, National Institute of Neurological Disorders and StrokesICH, symptomatic intracerebral hemorrhageTIA, transient ischemic attack.
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72
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Raya A, Zipfel GJ, Diringer MN, Dacey RG, Derdeyn CP, Rich KM, Chicoine MR, Dhar R. Pattern Not Volume of Bleeding Predicts Angiographic Vasospasm in Nonaneurysmal Subarachnoid Hemorrhage. Stroke 2014; 45:265-7. [DOI: 10.1161/strokeaha.113.002629] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Spontaneous idiopathic subarachnoid hemorrhage (SAH) with a perimesencephalic bleeding pattern is usually associated with a benign course, whereas a diffuse bleeding pattern has been associated with a higher risk of vasospasm and disability. We evaluated whether volume of bleeding explains this disparity.
Methods—
Pattern and amount of bleeding (by Hijdra and intraventricular hemorrhage scores) were assessed in 89 patients with nonaneurysmal SAH. Outcomes included angiographic vasospasm, delayed cerebral ischemia, and functional outcome at 1 year.
Results—
Diffuse bleeding was associated with significantly higher Hijdra and intraventricular hemorrhage scores than perimesencephalic SAH,
P
≤0.003. Angiographic vasospasm was more likely in diffuse versus perimesencephalic SAH (45% versus 27%; odds ratio, 2.9;
P
=0.08), but adjustment for greater blood burden only partially attenuated this trend (adjusted odds ratio, 2.2; 95% confidence interval, 0.69–7.2;
P
=0.18); delayed cerebral ischemia was only seen in those with diffuse bleeding. Patients with diffuse bleeding were less likely to be discharged home (68% versus 90%;
P
=0.01) and tended to have more residual disability (modified Rankin scale, 3–6; 20% versus 6%;
P
=0.18).
Conclusions—
Nonaneurysmal SAH can still result in vasospasm and residual disability, especially in those with diffuse bleeding. This disparity is only partially accounted for by greater cisternal or intraventricular blood, suggesting that the mechanism and distribution of bleeding may be as important as the amount of hemorrhage in patients with idiopathic SAH.
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73
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Dacey RG, Zipfel GJ, Limbrick DD. Editorial: neurosurgical winners. J Neurosurg 2013; 120:725-6. [PMID: 24359007 DOI: 10.3171/2013.8.jns131488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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74
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Lin AL, Liu J, Evans J, Leuthardt EC, Rich KM, Dacey RG, Dowling JL, Kim AH, Zipfel GJ, Grubb RL, Huang J, Robinson CG, Simpson JR, Linette GP, Chicoine MR, Tran DD. Codeletions at 1p and 19q predict a lower risk of pseudoprogression in oligodendrogliomas and mixed oligoastrocytomas. Neuro Oncol 2013; 16:123-30. [PMID: 24285548 DOI: 10.1093/neuonc/not142] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Pseudoprogression (PsP) occurs at a higher rate in glioblastoma multiforme with a methylated MGMT promoter-a subset with increased sensitivity to chemoradiotherapy and better overall prognosis. In oligodendroglioma (OG) and oligoastrocytoma (OA), presence of 1p/19q codeletions is highly predictive of response to treatment and is often associated with the methylated MGMT promoter; hence, this study queries whether the presence of 1p/19q codeletions in OG/OA correlates with a higher rate of PsP following therapy. METHODS A retrospective analysis was performed on all OG/OA in a database of patients with brain tumors who underwent resection of their tumor since 1998. Eighty-eight cases (37 with and 51 without 1p/19q codeletions) met inclusion criteria, and their patient data were analyzed to determine whether the presence of 1p/19q codeletions was associated with PsP and survival. RESULTS OG/OA (World Health Organization grades II and III) with 1p/19q codeletions had a significantly improved survival (P = .041). Multivariate analysis found that PsP occurred less frequently in OG/OA with 1p/19q codeletions compared with tumors without codeletions (odds ratio, 0.047; 95% confidence interval, 0.005-0.426; P = .0066). The rate of PsP was 19% for the entire cohort, 31% for tumors without codeletions, and 3% for tumors with codeletions. When early posttreatment contrast enhancement developed in tumors with 1p/19q codeletions, it occurred exclusively in tumors that were histologically OA and not OG. CONCLUSION Codeletions of 1p/19q are a marker of good prognosis but are unexpectedly associated with a lower likelihood of PsP. PsP does not correlate with sensitivity to treatment and improved survival in OG/OA.
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75
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Washington CW, Ju T, Zipfel GJ, Dacey RG. Middle cerebral artery bifurcation aneurysms: an anatomic classification scheme for planning optimal surgical strategies. Neurosurgery 2013; 10 Suppl 1:145-53; discussion 153-5. [PMID: 24226424 DOI: 10.1227/neu.0000000000000250] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Changing landscapes in neurosurgical training and increasing use of endovascular therapy have led to decreasing exposure in open cerebrovascular neurosurgery. To ensure the effective transition of medical students into competent practitioners, new training paradigms must be developed. OBJECTIVE Using principles of pattern recognition, we created a classification scheme for middle cerebral artery (MCA) bifurcation aneurysms that allows their categorization into a small number of shape pattern groups. METHODS Angiographic data from patients with MCA aneurysms between 1995 and 2012 were used to construct 3-dimensional models. Models were then analyzed and compared objectively by assessing the relationship between the aneurysm sac, parent vessel, and branch vessels. Aneurysms were then grouped on the basis of the similarity of their shape patterns in such a way that the in-class similarities were maximized while the total number of categories was minimized. For each category, a proposed clip strategy was developed. RESULTS From the analysis of 61 MCA bifurcation aneurysms, 4 shape pattern categories were created that allowed the classification of 56 aneurysms (91.8%). The number of aneurysms allotted to each shape cluster was 10 (16.4%) in category 1, 24 (39.3%) in category 2, 7 (11.5%) in category 3, and 15 (24.6%) in category 4. CONCLUSION This study demonstrates that through the use of anatomic visual cues, MCA bifurcation aneurysms can be grouped into a small number of shape patterns with an associated clip solution. Implementing these principles within current neurosurgery training paradigms can provide a tool that allows more efficient transition from novice to cerebrovascular expert.
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