Category: Vascular

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Anterior Communicating Artery Aneurysm Morphology and the Risk of Rupture

World Neurosurg. (2018) 109:119-126.

Recently, with improvements in computed tomography angiography and digital subtraction angiography, the assessment of certain morphologic traits of anterior communicating artery aneurysms (ACoAA) has drawn great attention. The determination of specific factors associated with rupture would provide much-needed guidance for the treatment of unruptured intracranial aneurysms, such as surgical clipping or endovascular coiling. Morphologic factors include, but are not limited to, aneurysm size, number, shape, dome direction, neck/dome ratio, and relationship of the aneurysm to the surrounding vessels. However, the results of previous investigations concerning morphologic parameters have yielded inconsistent results.

METHODS: This review presents and analyzes the literature on the morphology of ACoAAs and risk of rupture.

RESULTS: This literature review reveals that the strongest predictors of ACoAA rupture are size ratio, direction of the dome, and fenestration. These were the only factors that were either unanimously or near unanimously found to be predictive of rupture across multiple studies.

CONCLUSIONS: The size ratio, direction of the dome, and fenestration should be examined most meticulously when deciding when to treat an ACoAA.

 

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Posterior Inferior Cerebellar Artery/Vertebral Artery Subarachnoid Hemorrhage: A Comparison of Saccular vs Dissecting Aneurysms

Neurosurgery 82:93–98, 2018

Two distinct categories of aneurysms are described in relation to the posterior inferior cerebellar artery (PICA) and vertebral artery (VA): saccular (SA) and dissecting (DA) types. This distinction is often unrecognized because abnormalities here are uncommon and most studies are small.

OBJECTIVE: To determine if there are any differences in the clinical presentation, inhospital course, or outcomes in patients with DA vs SA of the PICA or VA.

METHODS: Thirty-eight patients with a VA or PICA aneurysm were identified from a departmental subarachnoid hemorrhage database and categorized into DA or SA types. Prospectively collecteddemographic and outcomedata (length of stay, discharge Glasgow Outcome Score) were supplemented by abstracting records for procedural data (extraventricular drain [EVD], ventriculoperitoneal [VP] shunt, tracheostomy, and nasogastric feeding). Univariate, binary logistic regression, and Cox regression analysis was used to compare patients with SA vs DA.

RESULTS: Three aneurysms related to arteriovenous malformation were excluded. Five patients were conservatively managed. Of the 30 treated cases, more patients with a DA presented in poor grade (6/13 vs 2/17 SA; P = .035).More DA patients required an EVD (85% vs 29%; P = .003), VP shunt (54% vs 6%; P = .003), tracheostomy (46% vs 6%; P < .01), and nasogastric feeding (85% vs 35%; P = .007). The median length of stay (41 vs 17 d, P < .001) was longer, and the age and injury severity adjusted odds of discharge home were significantly lower in the DA group (P=.008). Thirty-daymortality was not significantly different (23% of DA vs 24% of SA; P = .2).

CONCLUSION: The presentation, clinical course, and outcomes differ in patients with DA vs SA of the PICA and VA.

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Analysis of saccular aneurysms in the Barrow Ruptured Aneurysm Trial

J Neurosurg 128:120–125, 2018

The Barrow Ruptured Aneurysm Trial (BRAT) is a prospective, randomized trial in which treatment with clipping was compared to treatment with coil embolization. Patients were randomized to treatment on presentation with any nontraumatic subarachnoid hemorrhage (SAH). Because all other randomized trials comparing these 2 types of treatments have been limited to saccular aneurysms, the authors analyzed the current BRAT data for this subgroup of lesions.

METHODS The primary BRAT analysis included all sources of SAH: nonaneurysmal lesions; saccular, blister, fusiform, and dissecting aneurysms; and SAHs from an aneurysm associated with either an arteriovenous malformation or a fistula. In this post hoc review, the outcomes for the subgroup of patients with saccular aneurysms were further analyzed by type of treatment. The extent of aneurysm obliteration was adjudicated by an independent neuroradiologist not involved in treatment.

RESULTS Of the 471 patients enrolled in the BRAT, 362 (77%) had an SAH from a saccular aneurysm. Patients with saccular aneurysms were assigned equally to the clipping and the coiling cohorts (181 each). In each cohort, 3 patients died before treatment and 178 were treated. Of the 178 clip-assigned patients with saccular aneurysms, 1 (1%) was crossed over to coiling, and 64 (36%) of the 178 coil-assigned patients were crossed over to clipping. There was no statistically significant difference in poor outcome (modified Rankin Scale score > 2) between these 2 treatment arms at any recorded time point during 6 years of follow-up. After the initial hospitalization, 1 of 241 (0.4%) clipped saccular aneurysms and 21 of 115 (18%) coiled saccular aneurysms required retreatment (p < 0.001). At the 6-year follow-up, 95% (95/100) of the clipped aneurysms were completely obliterated, compared with 40% (16/40) of the coiled aneurysms (p < 0.001). There was no difference in morbidity between the 2 treatment groups (p = 0.10).

CONCLUSIONS In the subgroup of patients with saccular aneurysms enrolled in the BRAT, there was no significant difference between modified Rankin Scale outcomes at any follow-up time in patients with saccular aneurysms assigned to clipping compared with those assigned to coiling (intent-to-treat analysis). At the 6-year follow-up evaluation, rates of retreatment and complete aneurysm obliteration significantly favored patients who underwent clipping compared with those who underwent coiling. Clinical trial registration no.: NCT01593267 (clinicaltrials.gov)

 

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Comparison of endovascular and microsurgical management of 208 basilar apex aneurysms

J Neurosurg 127:1342–1352, 2017

The deep and difficult-to-reach location of basilar apex aneurysms, along with their location near critical adjacent perforating arteries, has rendered the perception that microsurgical treatment of these aneurysms is risky. As a result, these aneurysms are considered more suitable for treatment by endovascular intervention. The authors attempt to compare the immediate and long-term outcomes of microsurgery versus endovascular therapy for this aneurysm subtype.

METHODS A prospectively maintained database of 208 consecutive patients treated for basilar apex aneurysms between 2000 and 2012 was reviewed. In this group, 161 patients underwent endovascular treatment and 47 were managed microsurgically. The corresponding records were analyzed for presenting characteristics, postoperative complications, discharge status, and Glasgow Outcome Scale (GOS) scores up to 1 year after treatment and compared using chi-square and Student t-tests.

RESULTS Among these 208 aneurysms, 116 (56%) were ruptured, including 92 (57%) and 24 (51%) of the endovascularly and microsurgically managed aneurysms, respectively. The average Hunt and Hess grade was 2.4 (2.4 in the endovascular group and 2.2 in the microsurgical group; p = 0.472). Postoperative complications of cranial nerve deficits and hemiparesis were more common in patients treated microsurgically than endovascularly (55.3% vs 16.2%, p < 0.05; and 27.7% vs 10.6%, p < 0.05, respectively). However, aneurysm remnants and need for retreatment were more common in the endovascular than the microsurgical group (41.3% vs 2.3%, p < 0.05; and 10.6% vs 0.0%, p < 0.05, respectively). Stent placement significantly reduced the need for retreatment. Rehemorrhage rates and average GOS score at discharge and 1 year after treatment were not statistically different between the two treatment groups.

CONCLUSIONS Patients with basilar apex aneurysms were significantly more likely to be treated via endovascular management, but compared with those treated microsurgically, they had higher rates of recurrence and need for retreatment. The current study did not detect an overall difference in outcomes at discharge and 1 year after either treatment modality. Therefore, in a select group of patients, microsurgical treatment continues to play an important role.

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Stereotactic Radiosurgery for Brainstem Arteriovenous Malformations

Neurosurgery 81:910–920, 2017

The management of brainstem arteriovenous malformations (bAVMs) is a formidable challenge. bAVMs harbor higher morbidity and mortality compared to other locations.

OBJECTIVE: To review the outcomes following stereotactic radiosurgery (SRS) of bAVMs in a multicenter study.

METHODS: Six medical centers contributed data from 205 patients through the International Gamma Knife Research Foundation. Median age was 32 yr (6-81). Median nidus volume was 1.4 mL (0.1-69 mL). Favorable outcome (FO) was defined as AVM obliteration and no post-treatment hemorrhage or permanent symptomatic radiation-induced complications.

RESULTS: Overall obliteration was reported in 65.4% (n = 134) at a mean follow-up of 69 mo. Obliteration was angiographically proven in 53.2% (n = 109) and on MRA in 12.2% (n=25). Actuarial rate of obliteration at 2, 3, 5, 7, and 10 yr after SRS was 24.5%, 43.3%, 62.3%, 73%, and 81.8% respectively. Patients treated with a margin dose >20 Gy were more likely to achieve obliteration (P = .001). Obliteration occurred earlier in patients who received a higher prescribed margin dose (P = .05) and maximum dose (P = .041). Post-SRS hemorrhage occurred in 8.8% (n = 18). Annual post gamma knife latency period hemorrhage was 1.5%. Radiation-induced complications were radiologically evident in 35.6% (n = 73), symptomatic in 14.6% (n=30), and permanent in 14.6% (n=30, which included long-tract signs and new cranial nerve deficits). FO was achieved in 64.4% (n = 132). Predictors of an FO were a higher Virginia radiosurgery AVM scale score (P = .003), prior hemorrhage (P = .045), and a lower prescribed maximum dose (P = .006).

CONCLUSION: SRS for bAVMs results in obliteration and avoids permanent complications in the majority of patients.

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Anatomic Features of Paraclinoid Aneurysms

Neurosurgery 81:949–957, 2017

Paraclinoid aneurysms are among the most challenging aneurysms to treat. Computed tomography (CT) angiography helps in evaluating the radiological characteristics of these aneurysms next to bony structures.

OBJECTIVE: To present the CT angiography characteristics of paraclinoid aneurysms in order to better understand such pathology.

METHODS: The study examined CT angiography-based anatomical characteristics obtained retrospectively from 136 patients with 144 paraclinoid aneurysms selected from single-defined catchment populations in Finland. We examined the diameters of the parent artery (internal carotid artery), the location of the aneurysm, its dimensions (width, height, neck), and aneurysm wall irregularity.

RESULTS:We analyzed 144 paraclinoid aneurysms in 136 patients admitted to the hospital during 2000-2014.Multivariable analysis reveals that rupture aneurysms have the following radiological features: aneurysm larger than 5 mm in diameter (P = .006), irregular wall (P = .046), superior location, larger aspect ratio (P = .039), and neck wider than parent artery (P < .001).

CONCLUSION: Smaller diameter of the internal carotid artery and superior location, as well as a large and irregular aneurysm wall, are radiological characteristics of ruptured paraclinoid aneurysms, which CT angiography can measure easily.

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Surgical Performance in Minimally Invasive Surgery Plus Recombinant Tissue Plasminogen Activator for Intracerebral Hemorrhage Evacuation

Neurosurgery 81:860–866, 2017

Minimally invasive thrombolytic evacuation of intracerebral hematoma is being investigated in the ongoing phase III clinical trial of Minimally Invasive Surgery plus recombinant Tissue plasminogen activator for Intracerebral hemorrhage Evacuation (MISTIE III).

OBJECTIVE: To assess the accuracy of catheter placement and efficacy of hematoma evacuation in relation to surgical approach and surgeon experience.

METHODS:We performed a trial midpoint interim assessment of 123 cases that underwent the surgical procedure. Accuracy of catheter placement was prospectively assessed by the trial Surgical Center based on prearticulated criteria. Hematoma evacuation efficacy was evaluated based on absolute volume reduction, percentage hematoma evacuation, and reaching the target end-of-treatment volume of <15 mL. One of 3 surgical trajectories was used: anterior (A), posterior (B), and lobar (C). Surgeonswere classified based on experience with the MISTIE procedure as prequalified, qualified with probation, and fully qualified.

RESULTS: The average hematoma volume was 49.7 mL (range 20.0-124), and the mean evacuation rate was 71% (range 18.4%-99.8%). First placed catheters were 58% in good position, 28% suboptimal (but suitable to dose), and 14% poor (requiring repositioning). Posterior trajectory (B) was associated with significantly higher rates of poor placement (35%, P = .01). There was no significant difference in catheter placement accuracy among surgeons of varying experience. Hematoma evacuation efficacy was not significantly different among the 3 surgical approaches or different surgeons’ experience.

CONCLUSION: Ongoing surgical education and quality monitoring in MISTIE III have resulted in consistent rates of hematoma evacuation despite technical challenges with the surgical approaches and among surgeons of varying experience.

 

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Morphological and Hemodynamic Differences Between Aneurysmal Middle Cerebral Artery Bifurcation and Contralateral Nonaneurysmal Anatomy

Neurosurgery 81:779–786, 2017

The morphological and hemodynamic features differ between middle cerebral artery (MCA) bifurcations with and without aneurysms.

OBJECTIVE: To investigate the morphological and hemodynamic differences between aneurysmal MCA bifurcation and contralateral nonaneurysmal anatomy.

METHODS: Computed tomography angiography of 36 patients with unilateral small saccular MCA bifurcation aneurysms was evaluated. The parent–daughter angles (ϕ1 for larger branch and ϕ2 for smaller branch), bifurcation angle (ϕ = ϕ1 + ϕ2), inclination angle (γ angle), and their relationships with the MCA bifurcation locations were analyzed. Computational fluid dynamics simulation was performed in 6 cases to explore the hemodynamics influenced by the bifurcation morphology.

RESULTS: The ϕ angle was significantly higher in aneurysmal than contralateral nonaneurysmal bifurcations (160.8◦ ± 31.0◦ vs 99.0◦ ± 19.2◦, respectively; P = .000); the ϕ1, ϕ2, and γ angles were also higher. However, by regression analysis combined with MCA bifurcation locations, only the ϕ angle might be associated with the aneurysm presence (odds ratio = 1.120, 95% confidence interval = 1.059-1.185) and a ϕ angle cut-off of 124.8◦ was established. Computational fluid dynamics simulation demonstrated that flow resistance of the wider aneurysmal MCA bifurcation was significantly higher than that on the contralateral side.

CONCLUSION: A larger ϕ angle was more prevalent in aneurysmal than nonaneurysmal MCA bifurcations, and the higher flow resistance caused by the larger ϕ angle might be a potential hemodynamic factor associated with MCA aneurysm presence.

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A Reliable Grading System for Prediction of Chronic Subdural Hematoma Recurrence Requiring Reoperation After Initial Burr-Hole Surgery

Neurosurgery 81:752–760, 2017

There is no widely adopted grading system for the prediction of postoperative recurrence requiring reoperation (RrR) in patients with chronic subdural hematoma (CSDH).

OBJECTIVE: We developed a CSDH grading system to predict RrR based on predictive characteristics that can be objectively assessed at the time of first presentation and initial surgery.

METHODS: Prospectively collected data from 107 consecutive surgical patients with CSDH were reviewed. Predictors of RrR were identified via logistic and lasso regression analyses. A prognostic CSDH grading system was proposed, with the weighing of predictors based on strength of association. The scoring systemwas then applied to the same set of patients in our database for internal validation.

RESULTS: The strongest predictors of RrR were an isodense or hyperdense lesions and laminar or separated lesions, and a postoperative CSDH cavity volume greater than 200 mL. The moderate predictors of RrR were a postoperative CSDH cavity volume of 80 to 200 mL and a preoperative CSDH volume greater than 130 mL. According to the prognostic CSDH grading system, no patients with a score of 0 points had RrR. RrR was observed in 6% of patients with a score of 1 to 2 points, 30% of patients with a score of 3 to 4 points, and 63% of patients with a score of 5 points (ie, the maximum score). The rate of RrR increased steadily with increases in the prognostic CSDH grading score (P < .001).

CONCLUSION: The prognostic CSDH grading system is an applicable tool for RrR risk stratification in patients with CSDH.

 

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Microsurgery for Spetzler-Ponce Class A and B arteriovenous malformations utilizing an outcome score adopted from Gamma Knife radiosurgery

J Neurosurg 127:1105–1116, 2017

The purpose of this study was to adapt and apply the extended definition of favorable outcome established for Gamma Knife radiosurgery (GKRS) to surgery for brain arteriovenous malformations (bAVMs). The aim was to derive both an error around the point estimate and a model incorporating angioarchitectural features in order to facilitate comparison among different treatments.

METHODS A prospective microsurgical cohort was analyzed. This cohort included patients undergoing embolization who did not proceed to microsurgery and patients denied surgery because of perceived risk of treatment. Data on bAVM residual and recurrence during long-term follow-up as well as complications of surgery and preoperative embolization were analyzed. Patients with Spetzler-Ponce Class C bAVMs were excluded because of extreme selection bias. First, patients with a favorable outcome were identified for both Class A and Class B lesions. Patients were considered to have a favorable outcome if they were free of bAVM recurrence or residual at last follow-up, with no complication of surgery or preoperative embolization, and a modified Rankin Scale score of more than 1 at 12 months after treatment. Patients who were denied surgery because of perceived risk, but would otherwise have been candidates for surgery, were included as not having a favorable outcome. Second, the authors analyzed favorable outcome from microsurgery by means of regression analysis, using as predictors characteristics previously identified to be associated with complications. Third, they created a prediction model of favorable outcome for microsurgery dependent upon angioarchitectural variables derived from the regression analysis.

RESULTS From a cohort of 675 patients who were either treated or denied surgery because of perceived risk of surgery, 562 had Spetzler-Ponce Class A or B bAVMs and were included in the analysis. Logistic regression for favorable outcome found decreasing maximum diameter (continuous, OR 0.62, 95% CI 0.51–0.76), the absence of eloquent location (OR 0.23, 95% CI 0.12–0.43), and the absence of deep venous drainage (OR 0.19, 95% CI 0.10–0.36) to be significant predictors of favorable outcome. These variables are in agreement with previous analyses of microsurgery leading to complications, and the findings support the use of favorable outcome for microsurgery. The model developed for angioarchitectural features predicts a range of favorable outcome at 8 years following microsurgery for Class A bAVMs to be 88%–99%. The same model for Class B bAVMs predicts a range of favorable outcome of 62%–90%.

CONCLUSIONS Favorable outcome, derived from GKRS, can be successfully used for microsurgical cohort series to assist in treatment recommendations. A favorable outcome can be achieved by microsurgery in at least 90% of cases at 8 years following microsurgery for patients with bAVMs smaller than 2.5 cm in maximum diameter and, in the absence of either deep venous drainage or eloquent location, patients with Spetzler-Ponce Class A bAVMs of all diameters. For patients with Class B bAVMs, this rate of favorable outcome can only be approached for lesions with a maximum diameter just above 6 cm or smaller and without deep venous drainage or eloquent location.

 

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Timing of surgery for ruptured supratentorial arteriovenous malformations

Acta Neurochir (2017) 159:2103–2112

There are conflicting opinions regarding the optimal waiting time to perform surgery after rupture of supratentorial arteriovenous malformations (AVMs) to achieve the best possible outcome.

Objective To analyze factors influencing outcomes for ruptured supratentorial AVMs after surgery, paying particular attention to the timing of the surgery.

Methods We retrospectively investigated 59 patients admitted to our center between 2000 and 2014 for surgical treatment of ruptured supratentorial AVMs. We evaluated the effect of timing of surgery and other variables on the outcome at 2– 4 months (early outcome), at 12 months (intermediate outcome) after surgery, and at final follow-up at the end of 2016 (late outcome).

Results Age over 40 years (OR 18.4; 95% CI 1.9–172.1; p = 0.011), high Hunt and Hess grade (4 or 5) before surgery (OR 13.5; 95% CI 2.1–89.2; p = 0.007), hydrocephalus on admission (OR 12.9; 95% CI 1.8–94.4; p = 0.011), and over 400 cm3 bleeding during surgery (OR 11.5; 95% CI 1.5–86.6; p = 0.017) were associated with an unfavorable early outcome. Age over 40 years (OR 62.8; 95% CI 2.6–1524.9; p = 0.011), associated aneurysms (OR 34.7; 95% CI 1.4– 829.9; p = 0.029), high Hunt and Hess grade before surgery (OR 29.2; 95% CI 2.6–332.6; p = 0.007), and over 400 cm3 bleeding during surgery (OR 35.3; 95% CI 1.7–748.7; p = 0.022) were associated with an unfavorable intermediate outcome. Associated aneurysms (OR 8.2; 95% CI 1.2–55.7; p = 0.031), high Hunt and Hess grade before surgery (OR 5.7; 95% CI 1.3–24.3; p = 0.019), and over 400 cm3 bleeding during surgery (OR 5.8; 95% CI 1.2–27.3; p = 0.027) were associated with an unfavorable outcome at last follow-up. Elapsed time between rupture and surgery did not affect early or final outcome. Conclusions Early surgery in patients with ruptured supratentorial arteriovenous malformation is

Conclusions Early surgery in patients with ruptured supratentorial arteriovenous malformation is feasible strategy, with late results comparable to those achieved with delayed surgery. Many other factors than timing of surgery play significant roles in long-term outcomes for surgically treated ruptured supratentorial AVMs.

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Predictive factors for recurrence and clinical outcomes in patients with chronic subdural hematoma

J Neurosurg 127:1117–1125, 2017

Chronic subdural hematoma (CSDH) is a common type of intracranial hemorrhage in elderly patients. Many studies have suggested various factors that may be associated with the recurrence of CSDH. However, the results are inconsistent. The purpose of this study was to determine the associations among patient factors, recurrence, and clinical outcomes of CSDH after burr hole surgery performed during an 11-year period at twin hospitals.

METHODS Kaplan-Meier analysis was performed to evaluate the risk factors for CSDH recurrence. Univariate and multivariate Cox proportional hazards regression analyses were used to calculate hazard ratios with 95% CIs for CSDH recurrence based on many variables. One-way repeated-measures ANOVA was used to assess the differences in the mean modified Rankin Scale score between categories for each risk factor during each admission and at the last follow-up.

RESULTS This study was a retrospective analysis of 756 consecutive patients with CSDH who underwent burr hole surgery at the Hanyang University Medical Center (Seoul and Guri) between January 1, 2004, and December 31, 2014. During the 6-month follow-up, 104 patients (13.8%) with recurrence after surgery for CSDH were identified. Independent risk factors for recurrence were as follows: age > 75 years (HR 1.72, 95% CI 1.03–2.88; p = 0.039), obesity (body mass index ≥ 25.0 kg/m2), and a bilateral operation.

CONCLUSIONS This study determined the risk factors for recurrence of CSDH and their effects on outcomes. Further studies are needed to account for these observations and to determine their underlying mechanisms.

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Clinical relevance of anterior cerebral artery asymmetry in aneurysmal subarachnoid hemorrhage

J Neurosurg 127:1070–1076, 2017

An asymmetry of the A1 segments (A1SA) of the anterior cerebral arteries (ACAs) is an assumed risk factor for the development of anterior communicating artery aneurysms (ACoAAs). It is unknown whether A1SA is also clinically relevant after aneurysm rupture. The authors of this study investigated the impact of A1SA on the clinical course and outcome of patients with aneurysmal subarachnoid hemorrhage (SAH).

METHODS The authors retrospectively analyzed data on consecutive SAH patients treated at their institution between January 2005 and December 2012. The occurrence and severity of cerebral infarctions in the ACA territories were evaluated on follow-up CT scans up to 6 weeks after SAH. Moreover, the risk for an unfavorable outcome (defined as > 3 points on the modified Rankin Scale) at 6 months after SAH was assessed.

RESULTS A total of 594 patients were included in the final analysis. An A1SA was identified on digital subtraction angiography studies from 127 patients (21.4%) and was strongly associated with ACoAA (p < 0.0001, OR 13.7). An A1SA independently correlated with the occurrence of ACA infarction in patients with ACoAA (p = 0.047) and in those without an ACoAA (p = 0.015). Among patients undergoing ACoAA coiling, A1SA was independently associated with the severity of ACA infarction (p = 0.023) and unfavorable functional outcome (p = 0.045, OR = 2.4).

CONCLUSIONS An A1SA is a common anatomical variation in SAH patients and is strongly associated with ACoAA. Moreover, the presence of A1SA independently increases the likelihood of ACA infarction. In SAH patients undergoing ACoAA coiling, A1SA carries the risk for severe ACA infarction and thus an unfavorable outcome.

 

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Dexamethasone for chronic subdural haematoma: a systematic review and meta-analysis

Acta Neurochir (2017) 159:2037–2044

Chronic subdural haematoma is a common but retractable neurological disease in the elderly with a high rate of recurrence. Dexamethasone (DX) either as monotherapy or adjuvant therapy has been applied clinically, but its effectiveness and feasibility remain controversial. We conducted this review to clarify this issue. Methods With a systematic review through multiple databases, we retrieved eligible English language publications and extracted relevant data to perform meta-analyses. The respective risk ratio (RR) and its 95% confidence interval (CI) were pooled to evaluate the overall effect. Results Our meta-analysis showed overall that DX (alone or adjuvant) resulted in a lower recurrence rate when compared with non-DX therapy (RR, 0.54; 95% CI, 0.33-0.88; p = 0.01), but sensitivity analysis by excluding the most influential study achieved inconsistent results. The pooled effect revealed no statistical difference

Methods With a systematic review through multiple databases, we retrieved eligible English language publications and extracted relevant data to perform meta-analyses. The respective risk ratio (RR) and its 95% confidence interval (CI) were pooled to evaluate the overall effect. Results Our meta-analysis showed overall that DX (alone or adjuvant) resulted in a lower recurrence rate when compared with non-DX therapy (RR, 0.54; 95% CI, 0.33-0.88; p = 0.01), but sensitivity analysis by excluding the most influential study achieved inconsistent results. The pooled effect revealed no statistical difference

Results Our meta-analysis showed overall that DX (alone or adjuvant) resulted in a lower recurrence rate when compared with non-DX therapy (RR, 0.54; 95% CI, 0.33-0.88; p = 0.01), but sensitivity analysis by excluding the most influential study achieved inconsistent results. The pooled effect revealed no statistical difference on recurrence rate between DX alone and non-DX therapy or surgical therapy (RR, 0.86; 95% CI, 0.43-1.71; p = 0.66) (RR, 0.89; 95% CI, 0.43-1.85; p = 0.76). Comparison between DX alone with the surgical therapy demonstrated no difference on the poor outcome (RR, 0.40; 95% CI, 0.15-1.04; p = 0.06). Conclusions We had

Conclusions We had no enough evidence to support DX use as an effective alternation to surgical therapy. But adjuvant DX use may facilitate the surgical therapy by reducing recurrence. Further study focusing on adjuvant DX was required.

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Complex Internal Carotid Artery Aneurysm Treated by Extracranial to Intracranial Bypass Using High-Flow Grafts with Therapeutic Internal Carotid Artery Occlusion

Neurosurgery 81:672–679, 2017

Although the extracranial-to-intracranial high-flow bypass (EC-IC HFB) continues to be indispensable for complex aneurysms, the risk factors for the graft occlusion and whether the graft size changes after the bypass have not been well established.

OBJECTIVE: To evaluate the risk factors for the graft occlusion and to confirm whether graft diameters changed over time.

METHODS: The data of 75 patients who suffered from complex internal carotid artery (ICA) aneurysms and were treated by EC-IC HFB using radial artery graft (RAG) or saphenous vein graft (SVG) with therapeutic ICA occlusion were evaluated. Clinical and radiological characteristics were compared in patients with and without the graft occlusion by the logrank test. Graft diameters measured preoperatively, postoperatively, at 6 months, and at 1 year were compared by paired t-test.

RESULTS: During a follow-up period (median 26.2 months), graft occlusions were seen in 4 patients (5.3%), and these were the SVGs. Only SVG was related to graft occlusion (P<.001). There was a significant increase with time in RAG diameters (preoperative, 3.1 ± 0.41 mm; postoperative, 3.6 ± 0.65 mm; 6 months, 4.3 ± 1.0 mm; 1 year, 4.4 ± 1.0 mm), while there were no significant diameter changes in SVGs.

CONCLUSION: The present study showed that the SVG was related to the graft occlusion and RAGs gradually enlarged. Unless Allen test is negative, RAG may be better to be used as a graft in EC-IC HFB if therapeutic ICA occlusion is needed.

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The anterior temporal artery: an underutilized but robust donor for revascularization of the distal middle cerebral artery

J Neurosurg 127:740–747, 2017

The anterior temporal artery (ATA) supplies an area of the brain that, if sacrificed, does not cause a noticeable loss of function. Therefore, the ATA may be used as a donor in intracranial-intracranial (IC-IC) bypass procedures. The capacities of the ATA as a donor have not been studied previously. In this study, the authors assessed the feasibility of using the ATA as a donor for revascularization of different segments of the distal middle cerebral artery (MCA).

METHODS The ATA was studied in 15 cadaveric specimens (8 heads, excluding 1 side). First, the cisternal segment of the artery was untethered from arachnoid adhesions and small branches feeding the anterior temporal lobe and insular cortex, to evaluate its capacity for a side-to-side bypass to insular, opercular, and cortical segments of the MCA. Any branch entering the anterior perforated substance was preserved. Then, the ATA was cut at the opercular-cortical junction and the capacity for an end-to-side bypass was assessed.

RESULTS From a total of 17 ATAs, 4 (23.5%) arose as an early MCA branch. The anterior insular zone and the frontal parasylvian cortical arteries were the best targets (in terms of mobility and caliber match) for a side-to-side bypass. Most of the insula was accessible for end-to-side bypass, but anterior zones of the insula were more accessible than posterior zones. End-to-side bypass was feasible for most recipient cortical arteries along the opercula, except for posterior temporal and parietal regions. Early ATAs reached significantly farther on the insular MCA recipients than non-early ATAs for both side-to-side and end-to-side bypasses.

CONCLUSIONS The ATA is a robust arterial donor for IC-IC bypass procedures, including side-to-side and end-to-side techniques. The evidence provided in this work supports the use of the ATA as a donor for distal MCA revascularization in well-selected patients.

 

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Patient Selection and Clinical Efficacy of Urgent Superficial Temporal Artery-Middle Cerebral Artery Bypass in Acute Ischemic Stroke Using Advanced Magnetic Resonance Imaging Techniques

Operative Neurosurgery 13:552–559, 2017

Selected patients with acute ischemic stroke might benefit from superficial temporal artery-middle cerebral artery (STA-MCA) bypass, but the indications for urgent STA-MCA bypass are unknown.

OBJECTIVE: To report our experiences of urgent STA-MCA bypass in patients requiring urgent reperfusion who were ineligible for other reperfusion therapies, using advanced magnetic resonance imaging (MRI) techniques.

METHODS: The inclusion criteria for urgent STA-MCA bypass were as follows: acute infarct volume <70 mL with a ratio of perfusion/diffusion lesion volume ≥1.2, and a regional cerebral blood volume ratio >0.85. FromJanuary 2013 to October 2015, 21 urgent STA-MCA bypass surgeries were performed. The control group included 19 patients who did not undergo bypass surgery mainly due to refusal of surgery or the decision of the neurologist. Clinical and radiological data were compared between the surgery and control group.

RESULTS: The median age of the control group (70 years, interquartile range [IQR] 58-76) was higher than that of the surgery group (62 years, IQR 49-66), but the median preoperative diffusion and perfusion lesion volumes of the surgery group (13.8 mL, IQR 7.5-26.0 and 120.9 mL, IQR 84.9-176.0, respectively) were higher than those of the control group (5.6 mL, IQR 2.1-9.1 and 69.7 mL, IQR 23.9-125.3, respectively). Sixteen (76.2%) patients in the surgery group and 2 (10.5%) patients in the control group had favorable outcomes (P < .001). Logistic regression analysis identified bypass surgery as the strongest predictive factor.

CONCLUSION: STA-MCA bypass can be used as a therapeutic tool for acute ischemic stroke.Advanced MRI techniques are helpful for selecting patients and for decision making.

 

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Accuracy of 320-detector row nonsubtracted and subtracted volume CT angiography in evaluating small cerebral aneurysms

J Neurosurg 127:725–731, 2017

The study aimed to assess the diagnostic accuracy of 320-detector row nonsubtracted and subtracted volume CT angiography (VCTA) in detecting small cerebral aneurysms (< 3 mm) compared with 3D digital subtraction angiography (3D DSA).

METHODS Six hundred sixty-two patients underwent 320-detector row VCTA and 3D DSA for suspected cerebral aneurysms. Five neuroradiologists independently reviewed VCTA and 3D DSA images. The 3D DSA was considered the reference standard, and the sensitivity, specificity, and accuracy of nonsubtracted and subtracted VCTA in depicting small aneurysms were analyzed. A p value < 0.05 was considered a significant difference.

RESULTS According to 3D DSA images, 98 small cerebral aneurysms were identified in 90 of 662 patients. Nonsubtracted VCTA depicted 90 small aneurysms. Ten small aneurysms were missed, and 2 small aneurysms were misdiagnosed. The missed small aneurysms were located almost in the internal carotid artery, near bone tissue. The sensitivity, specificity, and accuracy of nonsubtracted VCTA in depicting small aneurysms were 89.8%, 99.2%, and 96.5%, respectively, on a per-aneurysm basis. Subtracted VCTA depicted 97 small aneurysms. Three small aneurysms were missed, and 2 small aneurysms were misdiagnosed. The sensitivity, specificity, and accuracy of subtracted VCTA in depicting small aneurysms were 96.9%, 99.2%, and 98.6%, respectively, on a per-aneurysm basis. There was no difference in accuracy between subtracted VCTA and 3D DSA (p = 1.000). However, nonsubtracted VCTA had significantly less sensitivity than 3D DSA and subtracted VCTA (p = 0.039 and 0.016, respectively).

CONCLUSIONS Subtracted 320-detector row VCTA is sensitive enough to replace 3D DSA in the diagnosis of small cerebral aneurysms (< 3 mm). The accuracy rate of nonsubtracted VCTA was lower than that of subtracted VCTA and 3D DSA, especially in the assessment of small internal carotid artery aneurysms adjacent to the skull base.

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The management and outcome for patients with chronic subdural hematoma: a prospective, multicenter, observational cohort study in the United Kingdom

J Neurosurg 127:732–739, 2017

Symptomatic chronic subdural hematoma (CSDH) will become an increasingly common presentation in neurosurgical practice as the population ages, but quality evidence is still lacking to guide the optimal management for these patients. The British Neurosurgical Trainee Research Collaborative (BNTRC) was established by neurosurgical trainees in 2012 to improve research by combining the efforts of trainees in each of the United Kingdom (UK) and Ireland’s neurosurgical units (NSUs). The authors present the first study by the BNTRC that describes current management and outcomes for patients with CSDH throughout the UK and Ireland. This provides a resource both for current clinical practice and future clinical research on CSDH.

METHODS Data on management and outcomes for patients with CSDH referred to UK and Ireland NSUs were collected prospectively over an 8-month period and audited against criteria predefined from the literature: NSU mortality < 5%, NSU morbidity < 10%, symptomatic recurrence within 60 days requiring repeat surgery < 20%, and unfavorable functional status (modified Rankin Scale score of 4–6) at NSU discharge < 30%.

RESULTS: Data from 1205 patients in 26 NSUs were collected. Bur-hole craniostomy was the most common procedure (89%), and symptomatic recurrence requiring repeat surgery within 60 days was observed in 9% of patients. Criteria on mortality (2%), rate of recurrence (9%), and unfavorable functional outcome (22%) were met, but morbidity was greater than expected (14%). Multivariate analysis demonstrated that failure to insert a drain intraoperatively independently predicted recurrence and unfavorable functional outcome (p = 0.011 and p = 0.048, respectively). Increasing patient age (p < 0.00001), postoperative bed rest (p = 0.019), and use of a single bur hole (p = 0.020) independently predicted unfavorable functional outcomes, but prescription of high-flow oxygen or preoperative use of antiplatelet medications did not.

CONCLUSIONS: This is the largest prospective CSDH study and helps establish national standards. It has confirmed in a real-world setting the effectiveness of placing a subdural drain. This study identified a number of modifiable prognostic factors but questions the necessity of some common aspects of CSDH management, such as enforced postoperative bed rest. Future studies should seek to establish how practitioners can optimize perioperative care of patients with CSDH to reduce morbidity as well as minimize CSDH recurrence. The BNTRC is unique worldwide, conducting multicenter trainee-led research and audits. This study demonstrates that collaborative research networks are powerful tools to interrogate clinical research questions.

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Impact of Timing of Intervention Among 397 Consecutively Treated Brainstem Cavernous Malformations

Neurosurgery 81:620–626, 2017

Surgical resection of brainstem cavernous malformations (BSCMs) is challenging, and patient selection and timing of intervention remain controversial.

OBJECTIVE: To evaluate the impact of surgical timing and predictors of neurological outcome after surgical resection of BSCMs.

METHODS: Consecutive adult patients (≥18 years) with BSCMs undergoing surgical resection between 1985 and 2014 by the senior author (RFS)were retrospectively reviewed. Patient demographics, lesion characteristics, imaging results, surgical approach, and perioperative and long-term neurological morbidity were analyzed.

RESULTS: Data were analyzed for a total of 397 adult patients (160, 40% male).On univariate analysis, a greater proportion of patients treated within 6 weeks of hemorrhage had an improved Glasgow Outcome Scale score (P = .06). On logistic regression analysis, patients treated within 6weeks of hemorrhage experienced improved clinical outcomes (odds ratio = 1.73; 95% confidence interval = 1.06-2.83; P = .03).

CONCLUSIONS: Although BSCM surgery is associated with significant perioperative morbidity and mortality, favorable long-term hemorrhage rates and symptom resolution can be achieved in a carefully selected group of patients. Overall, patients treated acutely, within 6 weeks, benefited the most from surgical intervention.

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