bluuebunny/crossref_metadata_2025 huggingface dataset:
Marketing Model
Authors: Siahaan Andysah Putera Utama , Ginting Maretta
Published: April 2019

This research is motivated by the problem of the competitiveness of horticulture products in Karo Regency which is still relatively low compared to other regions. The purpose of this study was to analyze the sustainable competitive advantage and performance of horticultural product marketing in Karo Regency which is influenced by factors of trust, norms and networks. This study used 148 horticultural farmers as respondents in 9 (nine) sub-districts in Karo Regency. Data were analyzed using PLS SEM with the help of WarpPLS software. The results of the study show that, based on direct influence, there was positive and significant influence of trust, norms and networks on sustainable competitive advantage. There was positive and significant influence of trust, network and sustainable competitive advantage on marketing performance. There was insignificant positive effect of norms on marketing performance.
Impact of Customer Perceived Value on Loyalty: In Context Crm
Authors: Ramadhan Lutfi , Siagian Yolanda Masnita
Published: April 2019

This study aims: 1) to Know whether the Customer Perceived Value affect Customer Relationship Management2) to Know whether the Customer Relationship Management affect Loyaltyand 3) to Know whether the Customer Perceived Value affect Loyaltymediated by CRM.This research is a quantitative approach, associative type. In this study, the population studied were 120 customers who were already members of Abbott Family Club loyalty as well who contacted via customer service on Pediasure Vanilla 850gr dairy products. And with samples that can describe population, then in determining the sample of this study using the technique non probability sampling with method Convenience Sampling.
PERBANDINGAN SISTEM KESEHATAN DI NEGARA BERKEMBANG DAN NEGARA MAJU
Authors: LAHAS ULRIKUS JULIANO
Published: April 2019

ULRIKUS JULIANO LAHAS
Jurnal_TEDC VOL 12 N.1, Januari 2018
Authors: Marlina Lusi
Published: April 2019

PENGAMBILAN MINYAK BIJI ALPUKATDENGAN METODE EKSTRAKSILusi Marlina1, Dian Wahyu Pratama21,2 Teknik Kimia - Politeknik TEDC BandungJl. Politeknik-Pesantren KM2 Cibabat Cimahi Utara – Cimahi Jawa Barat - Indonesialusi@poltektedc.ac.id, dianwahyu@gmail.comAbstrakDi Indonesia produksi alpukat sudah cukup tinggi, dapat dibuktikan dengan data produksi buah alpukat padatahun 2014 tercatat 307.326 ton per tahun. Bersamaan dengan produksi alpukat yang terus meningkat, makalimbah biji alpukat juga akan semakin meningkat. Biji alpukat merupakan salah satu sumber minyak nabatiyang berpotensi sebagai bahan baku pengganti. Maka perlu dilakukan penelitian tentang minyak biji alpukatyang didapatkan dengan metode ekstraksi menggunakan pelarut n-heksana dengan variabel proses volumepelarut, berat biji, dan waktu ekstraksi. Dalam mengetahui mutu dari minyak biji alpukat dilakukan analisa%yield, densitas, asam lemak bebas (%ALB), dan angka/bilangan asam. Data hasil penelitian menyatakankandungan minyak biji alpukat sebesar 32,8%. Penelitian ini mendapatkan %yield yang optimum karenadipengaruhi oleh variabel proses, dimana saat volume pelarut 250 ml, berat biji 50gr, dan waktu ekstraksi 90menit. Densitas yang didapatkan yaitu 0,7 – 0,74 gr/ml, kadar asam lemak bebas (%ALB) 0,96% - 1,61%, danuntuk angka/bilangan asam 0,785 – 1,570 mg KOH/gr.Kata kunci : Biji alpukat, ekstraksi, n-hexana, minyak biji nabatiAbstractIn Indonesia, avocado production is quite high, can be proven with data of avocado fruit production in 2014recorded 307,326 tons per year. Along with the increased avocado production, seeds avocado waste will alsoincrease. Seeds Avocado is one source of vegetable oil that has potential as a substitute raw material. So it isnecessary to do research on seeds avocado oil obtained by extraction method using n-hexane solvent withsolvent volume process variables, seed weight, and time of extraction. In knowing the quality of seeds avocadooil is done % yield analysis, density, free fatty acid (% ALB), and number / acid number. The results of researchdata indicate avocado seed oil content of 32.8 %. This study obtained an optimum yield % because it wasinfluenced by process variables, where the volume of solvent was 250 ml, seed weight 50 gr, and extractiontime 90 min. The density obtained was 0.7 - 0.74 gr / ml, free fatty acid content (% ALB) 0.96% - 1.61%, andfor the acid number 0.785 - 1.570 mg KOH / g.Keywords: Seeds of Avocado, extraction, n-hexane, vegetable seeds oil
And One More for the Road: Commentary on the Special Issue on Alcohol and Eyewitness Memory
Authors: Janssen Steve M. J. , Anne Michele
Published: April 2019

Studies examining the influences of alcohol intoxication have reported mixed findings on whether it impairs eyewitness memory. Although the studies in this Special Issue investigated different questions and tested different variables, the findings of these studies collectively provide insight into mechanisms and methodological issues that may explain the ambiguous findings of alcohol intoxication and eyewitness memory. In this commentary, we first describe the experimental studies of this Special Issue. We then discuss four mechanisms that could underlie those mixed findings (alcohol myopia, disinhibition, hypervigilance, meta-cognitive processes at retrieval). Last, we address methodological issues that may have contributed to those ambiguous findings (i.e., alcohol intoxication levels, automatic processing of stimuli, sensitivity of dependent variables, and possible interactions with arousal), and provide suggestions for future research to address these issues.
Simple Pleasures: How Goal-Aligned Behaviours Relate to State Happiness
Authors: Wang Kelly , Milyavskaya Marina
Published: April 2019

Goal progress has been consistently linked to subjective well-being and happiness (Klug & Maier, 2015), but do the individual actions of doing something helpful for personal goals have similar effects? The current study investigates how goal alignment – the perception that you are engaging in activities that are aligned with personal goals - might be associated with state happiness. We hypothesized that people will feel happier when the activities they are performing are aligned with their goals. The study also explored the roles of goal progress and competence in this relation. Data on goal-activity alignment, goal progress, competence, and state happiness were collected in an experience-sampling study with undergraduate students (N = 159) and a survey study with Amazon MTurk workers (N = 252). Using multilevel analyses and regression analyses, results indicated that participants were happier when they were pursuing activities that were more closely aligned with their goals than when pursuing less goal-aligned activities; the results remained significant after accounting for goal progress. Participants who were more goal-aligned on average reported greater state happiness; this effect was nonsignificant when goal progress was accounted for. Results suggest that goal alignment has a significant and unique effect on state happiness and that goal pursuit has very immediate benefits that begin as soon as individuals start doing actions helpful for their personal goals.
Hydroclimate variability influenced social interaction in the prehistoric American Southwest
Authors: Gauthier Nicolas
Published: April 2019

When droughts and floods struck ancient agrarian societies, complex networks of exchange and interaction channeled resources into affected settlements and migrant flows away from them. Did these networks evolve in part to connect populations living in differing climate regimes? Here, I examine this relationship with a long-term archaeological case study in the pre-Hispanic North American Southwest, analyzing 7.5 million artifacts from a 250-year period at nearly 500 archaeological sites. I use these artifacts to estimate how the flow of social information changed over time, and to measure how the intensity of social interaction between sites varied as a function of distance and several regional drought patterns. Social interaction decayed with distance, but ties between sites in differing oceanic and continental climate regimes were often stronger than expected. Accounting for these different regional drivers of local climate variability will be crucial for understanding the social impacts of droughts and floods in the past and present.
Degloving Injury: Different Ways of Management
Authors: Nakarmi Kiran K. , Shrestha Sikshya Prakash
Published: April 2019

Degloving injury involves shearing of the skin from the underlying tissue due to differential gliding in response to the tangential force applied to the surface of the body leading to disruption of all the blood vessels connected to skin. The flap of degloved skin has precarious blood supply making it almost impossible for the flap to survive. We describe two cases of degloving of thigh managed differently in different settings.
Selective motor fascicle transfer and neural-machine interface: case report
Authors: Takagi Takehiko , Ogiri Yosuke , Kato Ryu , Kodama Mitsuhiko , Yamanoi Yusuke , Nishino Wataru , Masakado Yoshihisa , Watanabe Masahiko
Published: April 2019

An amputated nerve transferred to a nearby muscle produces a transcutaneously detectable electromyographic signal corresponding to the transferred nerve; this technique is known as targeted muscle reinnervation (TMR). There are 2 issues to overcome to improve this technique: the caliber and the selectivity of the transferred nerve. It is optimal to select and transfer each motor fascicle to achieve highly developed myoelectric arms with multiple degrees-of-freedom motion. The authors report on a case in which they first identified the remnant stumps of the amputated median and radial nerves and then identified the sensory fascicles using somatosensory evoked potentials. Each median nerve fascicle was transferred to the long head branch of the biceps or the brachialis branch, while the short head branch of the biceps was retained for elbow flexion. Each radial nerve fascicle was transferred to the medial or lateral head branch of the triceps, while the long head branch of the triceps was retained for elbow extension. Electrophysiological and functional tests were conducted in the reinnervated muscles. Functional and electrophysiological improvement was noted, with marked improvement in the identification rate for each digit, forearm, and elbow motion after the selective nerve transfers. The authors note that more selective nerve transfers may be required for the development of prostheses with multiple degrees of freedom.
Correlation of perioperative risk scores with hospital costs in neurosurgical patients
Authors: Vaziri Sasha , Abbatematteo Joseph M. , Fleisher Max S. , Dru Alexander B. , Lockney Dennis T. , Kubilis Paul S. , Hoh Daniel J.
Published: April 2019

OBJECTIVE

The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) online surgical risk calculator uses inherent patient characteristics to provide predictive risk scores for adverse postoperative events. The purpose of this study was to determine if predicted perioperative risk scores correlate with actual hospital costs.

METHODS

A single-center retrospective review of 1005 neurosurgical patients treated between September 1, 2011, and December 31, 2014, was performed. Individual patient characteristics were entered into the NSQIP calculator. Predicted risk scores were compared with actual in-hospital costs obtained from a billing database. Correlational statistics were used to determine if patients with higher risk scores were associated with increased in-hospital costs.

RESULTS

The Pearson correlation coefficient (R) was used to assess the correlation between 11 types of predicted complication risk scores and 5 types of encounter costs from 1005 health encounters involving neurosurgical procedures. Risk scores in categories such as any complication, serious complication, pneumonia, cardiac complication, surgical site infection, urinary tract infection, venous thromboembolism, renal failure, return to operating room, death, and discharge to nursing home or rehabilitation facility were obtained. Patients with higher predicted risk scores in all measures except surgical site infection were found to have a statistically significant association with increased actual in-hospital costs (p < 0.0005).

CONCLUSIONS

Previous work has demonstrated that the ACS NSQIP surgical risk calculator can accurately predict mortality after neurosurgery but is poorly predictive of other potential adverse events and clinical outcomes. However, this study demonstrates that predicted high-risk patients identified by the ACS NSQIP surgical risk calculator have a statistically significant moderate correlation to increased actual in-hospital costs. The NSQIP calculator may not accurately predict the occurrence of surgical complications (as demonstrated previously), but future iterations of the ACS universal risk calculator may be effective in predicting actual in-hospital costs, which could be advantageous in the current value-based healthcare environment.
dl-3-n-butylphthalide for alleviation of neurological deficit after combined extracranial-intracranial revascularization for moyamoya disease: a propensity score–matched analysis
Authors: Li Zongze , Lu Junlin , Ma Li , Wu Chunxue , Xu Zongsheng , Chen Xiaolin , Ye Xun , Wang Rong , Zhao Yuanli
Published: April 2019

OBJECTIVE

Postoperative neurological deficits impair the overall outcome of revascularization surgery for patients with moyamoya disease (MMD). dl-3-n-butylphthalide (NBP) is approved for the treatment of ischemic stroke in China. This pilot study evaluated the effect of NBP on perioperative stroke and neurological deficits in patients with MMD.

METHODS

The authors studied cases in which patients underwent combined revascularization surgery for MMD at their institution, with or without NBP administration. The overall study group included 164 patients (213 surgically treated hemispheres), including 49 patients who received NBP (25 mg twice daily) for 7 postoperative days. The incidence of perioperative stroke and transient neurological deficit (TND) and the severity of neurological deficits were compared between 49 propensity score–matched case pairs with or without NBP treatment. Subgroup analyses by type of onset and preoperative neurological status were also performed to determine specific characteristics of patients who might benefit from NBP administration.

RESULTS

In the overall cohort, baseline characteristics differed with respect to preoperative stroke and modified Rankin Scale (mRS) score between patients who received NBP and those who did not receive it. In the 49 propensity score–matched pairs, postoperative stroke was observed in 11 patients and TND occurred in 21 patients, with no significant difference in incidence between the 2 groups. However, the TND was less severe in the NBP-treated group (p = 0.01). At 1 month after surgery, the neurological outcome was more favorable (p = 0.001) and the disability-free recovery rate was higher in patients with NBP treatment (p < 0.001). The number of patients who experienced an improved neurological function, compared to preoperative function, as measured by mRS, was greater in the NBP group than in the no-NBP group (p < 0.001). Multivariable analysis revealed that NBP administration was associated with decreased severity of TND (OR 0.28, p = 0.02), improved neurological function (OR 65.29, p = 0.04), and lower postoperative mRS score (OR 0.06, p < 0.001). These beneficial effects of NBP remained significant in ischemic type MMD and patients with preoperative mRS scores of 2 or greater.

CONCLUSIONS

Postoperative administration of NBP may alleviate perioperative neurological deficits after revascularization surgery for MMD, especially in patients with ischemic MMD and unfavorable preoperative status. The results of this study suggest that randomized controlled trials to assess the potential benefit of NBP in patients with MMD may be warranted.
Correlation between fractional anisotropy changes in the targeted ventral intermediate nucleus and clinical outcome after transcranial MR-guided focused ultrasound thalamotomy for essential tremor: results of a pilot study
Authors: Hori Hiroki , Yamaguchi Toshio , Konishi Yoshiyuki , Taira Takaomi , Muragaki Yoshihiro
Published: April 2019

OBJECTIVE

This study evaluated changes of fractional anisotropy (FA) in the ventral intermediate nucleus (VIM) of the thalamus after transcranial MR-guided focused ultrasound (TcMRgFUS) thalamotomy and their associations with clinical outcome.

METHODS

Clinical and radiological data of 12 patients with medically refractory essential tremor (mean age 76.5 years) who underwent TcMRgFUS thalamotomy with VIM targeting were analyzed retrospectively. The Clinical Rating Scale for Tremor (CRST) score was calculated before and at 1 year after treatment. Measurements of the relative FA (rFA) values, defined as ratio of the FA value in the targeted VIM to the FA value in the contralateral VIM, were performed before thalamotomy, and 1 day and 1 year thereafter.

RESULTS

TcMRgFUS thalamotomy was well tolerated and no long-term complications were noted. At 1-year follow-up, 8 patients demonstrated relief of tremor (improvement group), whereas in 4 others persistent tremor was noted (recurrence group). In the entire cohort, mean rFA values in the targeted VIM before treatment, and at 1 day and 1 year after treatment, were 1.12 ± 0.15, 0.44 ± 0.13, and 0.82 ± 0.22, respectively (p < 0.001). rFA values were consistently higher in the recurrence group compared with the improvement group, and the difference reached statistical significance at 1 day (p < 0.05) and 1 year (p < 0.01) after treatment. There was a statistically significant (p < 0.01) positive correlation between rFA values in the targeted VIM at 1 day after thalamotomy and CRST score at 1 year after treatment. Receiver operating characteristic curve analysis revealed that the optimal cutoff value of rFA at 1 day after thalamotomy for prediction of symptomatic improvement at 1-year follow-up is 0.54.

CONCLUSIONS

TcMRgFUS thalamotomy results in significant decrease of rFA in the targeted VIM, at both 1 day and 1 year after treatment. Relative FA values at 1 day after treatment showed significant correlation with CRST score at 1-year follow-up. Therefore, FA may be considered a possible imaging biomarker for early prediction of clinical outcome after TcMRgFUS thalamotomy for essential tremor.
Safety and efficacy of intravascular ultrasound as an adjunct to stenting for cerebral venous sinus stenosis–induced idiopathic intracranial hypertension: a pilot study
Authors: Yan Feng , Rajah Gary , Ding Yuchuan , Hua Yang , Zhang Hongqi , Jiao Liqun , Li Guilin , Ren Ming , Meng Ran , Lin Feng , Ji Xunming
Published: April 2019

OBJECTIVE

Symptomatic intracranial hypertension can be caused by cerebral venous sinus stenosis (CVSS) and cerebral venous sinus thrombotic (CVST) stenosis, which is usually found in some patients with idiopathic intracranial hypertension (IIH). Recently, at the authors’ center, they utilized intravascular ultrasound (IVUS) as an adjunct to conventional venoplasty or stenting to facilitate diagnosis and accurate stent placement in CVSS.

METHODS

The authors designed a retrospective review of their prospective database of patients who underwent IVUS-guided venous sinus stenting between April 2016 and February 2017. Clinical, radiological, and ophthalmological information was recorded and analyzed. IVUS was performed in 12 patients with IIH (9 with nonthrombotic CVSS, 3 with secondary stenosis combined with CVST) during venoplasty through venous access. The IVUS catheter was used from a proximal location to the site of stenosis. Post-stenting follow-up, including symptomatic improvement, stent patency, and adjacent-site stenosis, was assessed at 1 year.

RESULTS

Thirteen stenotic cerebral sinuses in 12 patients were corrected using IVUS-guided stenting. No technical or neurological complications were encountered. The IVUS images were excellent for the diagnosis of the stenosis, and intraluminal thrombi were clearly visualized by using IVUS in 3 (25%) of the 12 patients. A giant arachnoid granulation was demonstrated in 1 (8.3%) of the 12 patients. Intravenous compartments or septations (2 of 12, 16.7%) and vessel wall thickening (6 of 12, 50%) were also noted. At 1-year follow-up, 10 of 12 patients were clinically symptom-free in our series.

CONCLUSIONS

IVUS is a promising tool with the potential to improve the diagnostic accuracy in IIH, aiding in identification of the types of intracranial venous stenosis, assisting in stent selection, and guiding stent placement. Further study of the utility of IVUS in venous stenting and venous stenosis pathology is warranted.
Sublaminar banding as an adjunct to pedicle screw-rod constructs: a review and technical note on novel hybrid constructs in spinal deformity surgery
Authors: Viswanathan Vibhu K. , Minnema Amy J. , Viljoen Stephanus , Farhadi H. Francis
Published: April 2019

Sublaminar implants that encircle cortical bone are well-established adjuncts to pedicle screw-rod constructs in pediatric deformity surgery. Sublaminar bands (SLBs) in particular carry the advantage of relatively greater bone contact surface area as compared to wires and pullout loads that are independent of bone mineral density, in contrast to pedicle screws. Whereas the relevant technical considerations have been reported for pediatric deformity correction, an understanding of the relative procedural specifics of these techniques is missing for adult spinal deformity (ASD), despite several case series that have used distinct posterior tethering techniques for proximal junctional kyphosis prevention. In this paper, the authors summarize the relevant literature and describe a novel technique wherein bilateral tensioned SLBs are introduced at the nonfused proximal junctional level of long-segment ASD constructs.
Orbital reconstruction for tumor-associated proptosis: quantitative analysis of postoperative orbital volume and final eye position
Authors: Heller Robert S. , David Carlos A. , Heilman Carl B.
Published: April 2019

OBJECTIVE

Surgical resection of sphenoid wing tumors and intraorbital pathology carries the dual goal of appropriately treating the target pathology as well as correcting proptosis. Residual proptosis following surgery can lead to cosmetic and functional disability. The authors sought to quantitatively assess the effect of orbital volume before and after reconstruction to determine the optimal strategy to achieve proptosis correction.

METHODS

All surgeries involving orbital wall reconstruction for orbital or intracranial pathology that preoperatively resulted in proptosis between 2007 and 2017 were reviewed. Proptosis was measured by the exophthalmos index (EI): the ratio of the distance of the anterior limit of each globe to a line drawn between the anterior limit of the frontal processes of the zygomas, comparing the pathological eye to the normal eye. Postoperative radiographic measurements were taken at least 60 days after surgery to allow surgical swelling to abate. The orbit contralateral to the pathology was used as an internal control for normal anatomical orbital volume. Cases with preoperative EI < 1.10, orbital exenteration, or enucleation were excluded.

RESULTS

Twenty-three patients (16 females and 7 males, with a mean age of 43.6 ± 22.8 years) were treated surgically for tumor-associated proptosis. Nineteen patients harbored meningiomas (11 en-plaque; 8 sphenoid wing), and one patient each harbored an orbital schwannoma, glomangioma, arteriovenous malformation, or cavernous hemangioma. Preoperative EI averaged 1.28 ± 0.10 (range 1.12–1.53). Median time to postoperative imaging was 19 months. Postoperatively, the EI decreased to a mean of 1.07 ± 0.09. Greater increases in size of the reconstructed orbit were positively correlated with greater quantitative reductions in proptosis (p < 0.01). Larger volume of soft tissue pathology was also associated with achieving greater proptosis correction (p < 0.01). Residual exophthalmos (defined as EI > 1.10) was present in 8 patients, while reconstruction in 2 patients resulted in clinically asymptomatic enophthalmos (defined as EI < 0.95). Tumor invasion into the superior orbital fissure sinus was associated with residual proptosis (p = 0.04).

CONCLUSIONS

Proptosis associated with intracranial and orbital pathology represents a surgical challenge. The EI is a reliable and quantitative assessment of proptosis. For orbital reconstruction in cases of superior orbital fissure involvement, surgeons should consider rebuilding the orbit at slightly larger than anatomical volume.
Retrosigmoid approach for glycerin rhizotomy in the treatment of trigeminal neuralgia without overt arterial compression: updated case series
Authors: Kim Timothy Y. , Jackson Christopher M. , Xia Yuanxuan , Mashouf Leila A. , Patel Kisha K. , Kim Eileen S. , Hung Alice L. , Wu Adela , Garzon-Muvdi Tomas , Bender Matthew T. , Bettegowda Chetan , Lee John Y. K. , Lim Michael
Published: April 2019

OBJECTIVE

Trigeminal neuralgia (TN) is a neuropathic pain disorder characterized by severe, lancinating facial pain that is commonly treated with neuropathic medication, percutaneous rhizotomy, and/or microvascular decompression (MVD). Patients who are not found to have distinct arterial compression during MVD present a management challenge. In 2013, the authors reported on a small case series of such patients in whom glycerin was injected intraoperatively into the cisternal segment of the trigeminal nerve. The objective of the authors’ present study was to report their updated experience with this technique to further validate this novel approach.

METHODS

The authors performed a retrospective analysis of data obtained in patients in whom glycerin was directly injected into the inferior third of the cisternal portion of the trigeminal nerve. Seventy-four patients, including 14 patients from the authors’ prior study, were identified, and demographic information, intraoperative findings, postoperative course, and complications were recorded. Fisher’s exact test, unpaired t-tests, and Kaplan-Meier survival curves using Mantel log-rank test were used to compare the 74 patients with a cohort of 476 patients who received standard MVD by the same surgeon.

RESULTS

The 74 patients who underwent MVD and glycerin injection had an average follow-up of 19.1 ± 18.0 months, and the male/female ratio was 1:2.9. In 33 patients (44.6%), a previous intervention for TN had failed. On average, patients had an improvement in the Barrow Neurological Institute Pain Intensity score from 4.1 ± 0.4 before surgery to 2.1 ± 1.2 after surgery. Pain improvement after the surgery was documented in 95.9% of patients. Thirteen patients (17.6%) developed burning pain following surgery. Five patients developed complications (6.7%), including incisional infection, facial palsy, CSF leak, and hearing deficit, all of which were minor.

CONCLUSIONS

Intraoperative injection of glycerin into the trigeminal nerve is a generally safe and potentially effective treatment for TN when no distinct site of arterial compression is identified during surgery or when decompression of the nerve is deemed to be inadequate.
Decreased wall shear stress at high-pressure areas predicts the rupture point in ruptured intracranial aneurysms
Authors: Suzuki Tomoaki , Stapleton Christopher J. , Koch Matthew J. , Tanaka Kazutoshi , Fujimura Soichiro , Suzuki Takashi , Yanagisawa Takeshi , Yamamoto Makoto , Fujii Yukihiko , Murayama Yuichi , Patel Aman B.
Published: April 2019

OBJECTIVE

Degenerative cerebral aneurysm walls are associated with aneurysm rupture and subarachnoid hemorrhage. Thin-walled regions (TWRs) represent fragile areas that may eventually lead to aneurysm rupture. Previous computational fluid dynamics (CFD) studies reported the correlation of maximum pressure (Pmax) areas and TWRs; however, the correlation with aneurysm rupture has not been established. This study aims to investigate this hemodynamic correlation.

METHODS

The aneurysmal wall surface at the Pmax areas was intraoperatively evaluated using a fluid flow formula under pulsatile blood flow conditions in 23 patients with 23 saccular middle cerebral artery (MCA) bifurcation aneurysms (16 unruptured and 7 ruptured). The pressure difference (Pd) at the Pmax areas was calculated by subtracting the average pressure (Pave) from the Pmax and normalized by dividing this by the dynamic pressure at the aneurysm inlet side. The wall shear stress (WSS) was also calculated at the Pmax areas, aneurysm dome, and parent artery. These hemodynamic parameters were used to validate the correlation with TWRs in unruptured MCA aneurysms. The characteristic hemodynamic parameters at the rupture points in ruptured MCA aneurysms were then determined.

RESULTS

In 13 of 16 unruptured aneurysms (81.2%), Pmax areas were identified that corresponded to TWRs. In 5 of the 7 ruptured cerebral aneurysms, the Pmax areas coincided with the rupture point. At these areas, the Pd values were not higher than those of the TWRs in unruptured cerebral aneurysms; however, minimum WSS, time-averaged WSS, and normalized WSS at the rupture point were significantly lower than those of the TWRs in unruptured aneurysms (p < 0.01).

CONCLUSIONS

At the Pmax area of TWRs, decreased WSS appears to be the crucial hemodynamic parameter that indicates the risk of aneurysm rupture.
The incidence of chronic subdural hematomas from 1990 to 2015 in a defined Finnish population
Authors: Rauhala Minna , Luoto Teemu M. , Huhtala Heini , Iverson Grant L. , Niskakangas Tero , Öhman Juha , Helén Pauli
Published: April 2019

OBJECTIVE

The aim of this study was to determine the population-based epidemiology of chronic subdural hematoma (CSDH) over a 26-year period.

METHODS

A retrospective study was conducted of all adult patients (≥ 18 years and residents of Pirkanmaa [Finland]) with a diagnosis of CSDH between 1990 and 2015. The cases were identified using ICD codes. Detailed data collection was performed using medical records and death certificates. All patients were monitored until death or the end of year 2017. The annual number of inhabitants in the Pirkanmaa region was obtained from Statistics Finland (Helsinki, Finland).

RESULTS

A total of 1168 patients with CSDH were identified from hospital records and death certificates; patients were considered as new-incidence cases if 2 years had elapsed following primary treatment and in cases involving a new contralateral CSDH. From 1990 to 2015, the overall incidence of CSDH doubled from 8.2 to 17.6/100,000/year. Among adults younger than 70 years, the incidence remained quite stable, whereas the incidence clearly increased among the ≥ 80-year-old population, from 46.9 to 129.5/100,000/year. The median age for a CSDH diagnosis increased from 73 to 79 years during the 26-year period. Head trauma was documented in 59% of cases. A ground-level fall was related to the CSDH in 31% of patients younger than 60 years and in 54% of those 80 years or older. The proportion of alcohol-related cases decreased toward the end of the study period (1990–1995: 16% and 2011–2015: 7%), because alcohol abuse was less frequent among the growing group of elderly patients. In contrast, the percentage of patients receiving anticoagulant or antiplatelet medication almost doubled toward 2015 (1990–1995, 27%; and 2011–2015, 49%). The patients’ neurological condition on admission, based on both Glasgow Coma Scale score (score < 13: 1990–1995, 18%; and 2011–2015, 7%; p < 0.001) and the modified Rankin Scale score (score 0–2: 1990–1995, 8%; and 2011–2015, 19%; p < 0.001), was better in recent years than in the early 1990s.

CONCLUSIONS

From 1990 to 2015, the incidence of CSDH has increased markedly. The incidence of CSDH among the population 80 years or older has nearly tripled since 1990. The use of anticoagulants has increased, but there has been no change regarding the ratio between a traumatic and a spontaneous CSDH etiology. As the world population becomes progressively older, the increasing incidence of CSDH will be a burden to patients and a future challenge for neurosurgical clinics.
Anatomical triangles defining routes to anterior communicating artery aneurysms: the junctional and precommunicating triangles and the role of dome projection
Authors: Ivan Michael E. , Safaee Michael M. , Martirosyan Nikolay L. , Rodríguez-Hernández Ana , Sullinger Barbara , Kuruppu Priyanka , Habdank-Kolaczkowski Julian , Lawton Michael T.
Published: April 2019

OBJECTIVE

Anterior communicating artery (ACoA) aneurysms are common intracranial aneurysms. Despite advances in endovascular therapy, microsurgical clipping remains an important treatment for aneurysms with broad necks, large size, intraluminal thrombus, complex branches, or previous coiling. Anatomical triangles identify safe corridors for aneurysm access. The authors introduce the A1-A2 junctional triangle and the A1-A1 precommunicating triangle and examine relationships between dome projection, triangular corridors of access, and surgical outcomes.

METHODS

Preoperative catheter and CT angiograms were evaluated to characterize aneurysm dome projection. Aneurysm projection was categorized into quadrants and octants. Preoperative, intraoperative, and postoperative factors were correlated to aneurysm dome projection and patient outcomes using univariate and multivariate analyses.

RESULTS

A total of 513 patients with microsurgically treated ACoA aneurysms were identified over a 13-year period, and 400 had adequate imaging and follow-up data for inclusion. Surgical clipping was performed on 271 ruptured and 129 unruptured aneurysms. Good outcomes were observed in 91% of patients with unruptured aneurysms and 86% of those with ruptured aneurysms, with a mortality rate < 1% among patients with unruptured aneurysms. Increasing age (p < 0.01), larger aneurysm size (p = 0.03), and worse preoperative modified Rankin Scale score (p < 0.01) affected outcomes adversely. Aneurysms projecting superiorly and posteriorly required dissection in the junctional triangle, and multivariate analysis demonstrated worse clinical outcomes in these patients (p < 0.01).

CONCLUSIONS

Anteriorly and inferiorly projecting aneurysms involve only the precommunicating triangle, are simpler to treat microsurgically, and have more favorable outcomes. Superior and posterior dome projections make ACoA aneurysms more difficult to visualize and require opening the junctional triangle. Added visualization through the junctional triangle is recommended for these aneurysms in order to facilitate dissection of efferent branch arteries, careful clip application, and perforator preservation. Dome projection can be determined preoperatively from images and can help anticipate dissection routes through the junctional triangle.
Augmented reality–assisted pedicle screw insertion: a cadaveric proof-of-concept study
Authors: Molina Camilo A. , Theodore Nicholas , Ahmed A. Karim , Westbroek Erick M. , Mirovsky Yigal , Harel Ran , Orru’ Emanuele , Khan Majid , Witham Timothy , Sciubba Daniel M.
Published: April 2019

OBJECTIVE

Augmented reality (AR) is a novel technology that has the potential to increase the technical feasibility, accuracy, and safety of conventional manual and robotic computer-navigated pedicle insertion methods. Visual data are directly projected to the operator’s retina and overlaid onto the surgical field, thereby removing the requirement to shift attention to a remote display. The objective of this study was to assess the comparative accuracy of AR-assisted pedicle screw insertion in comparison to conventional pedicle screw insertion methods.

METHODS

Five cadaveric male torsos were instrumented bilaterally from T6 to L5 for a total of 120 inserted pedicle screws. Postprocedural CT scans were obtained, and screw insertion accuracy was graded by 2 independent neuroradiologists using both the Gertzbein scale (GS) and a combination of that scale and the Heary classification, referred to in this paper as the Heary-Gertzbein scale (HGS). Non-inferiority analysis was performed, comparing the accuracy to freehand, manual computer-navigated, and robotics-assisted computer-navigated insertion accuracy rates reported in the literature. User experience analysis was conducted via a user experience questionnaire filled out by operators after the procedures.

RESULTS

The overall screw placement accuracy achieved with the AR system was 96.7% based on the HGS and 94.6% based on the GS. Insertion accuracy was non-inferior to accuracy reported for manual computer-navigated pedicle insertion based on both the GS and the HGS scores. When compared to accuracy reported for robotics-assisted computer-navigated insertion, accuracy achieved with the AR system was found to be non-inferior when assessed with the GS, but superior when assessed with the HGS. Last, accuracy results achieved with the AR system were found to be superior to results obtained with freehand insertion based on both the HGS and the GS scores. Accuracy results were not found to be inferior in any comparison. User experience analysis yielded “excellent” usability classification.

CONCLUSIONS

AR-assisted pedicle screw insertion is a technically feasible and accurate insertion method.
Estimating a price point for cost-benefit of bone morphogenetic protein in pseudarthrosis prevention for adult spinal deformity surgery
Authors: Safaee Michael M. , Dalle Ore Cecilia L. , Zygourakis Corinna C. , Deviren Vedat , Ames Christopher P.
Published: April 2019

OBJECTIVE

Bone morphogenetic protein (BMP) is associated with reduced rates of pseudarthrosis and has the potential to decrease the need for revision surgery. There are limited data evaluating the cost-benefit of BMP for pseudarthrosis-related prevention surgery in adult spinal deformity.

METHODS

The authors performed a single-center retrospective review of 200 consecutive patients with adult spinal deformity. Demographic data and costs of BMP, primary surgery, and revision surgery for pseudarthrosis were collected. Patients with less than 12 months of follow-up or with infection, tumor, or neuromuscular disease were excluded.

RESULTS

One hundred fifty-one patients (107 [71%] women) with a mean age of 65 years met the inclusion criteria. The mean number of levels fused was 10; BMP was used in 98 cases (65%), and the mean follow-up was 23 months. Fifteen patients (10%) underwent surgical revision for pseudarthrosis; BMP use was associated with an 11% absolute risk reduction in the rate of reoperation (17% vs 6%, p = 0.033), with a number needed to treat of 9.2. There were no significant differences in age, sex, upper instrumented vertebra, or number of levels fused in patients who received BMP. In a multivariate model including age, sex, number of levels fused, and the upper instrumented vertebra, only BMP (OR 0.250, 95% CI 0.078–0.797; p = 0.019) was associated with revision surgery for pseudarthrosis. The mean direct cost of primary surgery was $87,653 ± $19,879, and the mean direct cost of BMP was $10,444 ± $4607. The mean direct cost of revision surgery was $52,153 ± $26,985. The authors independently varied the efficacy of BMP, cost of BMP, and cost of reoperation by ± 50%; only reductions in the cost of BMP resulted in a cost savings per 100 patients. Using these data, the authors estimated a price point of $5663 in order for BMP to be cost-neutral.

CONCLUSIONS

Use of BMP was associated with a significant reduction in the rates of revision surgery for pseudarthrosis. At its current price, the direct in-hospital costs for BMP exceed the costs associated with revision surgery; however, this likely underestimates the true value of BMP when considering the savings associated with reductions in rehabilitation, therapy, medication, and additional outpatient costs.
Spinal trauma in Tanzania: current management and outcomes
Authors: Leidinger Andreas , Kim Eliana E. , Navarro-Ramirez Rodrigo , Rutabasibwa Nicephorus , Msuya Salim R. , Askin Gulce , Greving Raphael , Shabani Hamisi K. , Härtl Roger
Published: April 2019

OBJECTIVE

Spinal trauma is a major cause of disability worldwide. The burden is especially severe in low-income countries, where hospital infrastructure is poor, resources are limited, and the volume of cases is high. Currently, there are no reliable data available on incidence, management, and outcomes of spinal trauma in East Africa. The main objective of this study was to describe, for the first time, the demographics, management, costs of surgery and implants, treatment decision factors, and outcomes of patients with spine trauma in Tanzania.

METHODS

The authors retrospectively reviewed prospectively collected data on spinal trauma patients in the single surgical referral center in Tanzania (Muhimbili Orthopaedic Institute [MOI]) from October 2016 to December 2017. They collected general demographics and the following information: distance from site of trauma to the center, American Spinal Injury Association Impairment Scale (AIS), time to surgery, steroid use, and mechanism of trauma and AOSpine classification and costs. Surgical details and complications were recorded. Primary outcome was neurological status on discharge. The authors analyzed surgical outcome and determined predicting factors for positive outcome.

RESULTS

A total of 180 patients were included and analyzed in this study. The mean distance from site of trauma to MOI was 278.0 km, and the time to admission was on average 5.9 days after trauma. Young males were primarily affected (82.8% males, average age 35.7 years). On admission, 47.2% of patients presented with AIS grade A. Most common mechanisms of injury were motor vehicle accidents (28.9%) and falls from height (32.8%). Forty percent of admitted patients underwent surgery. The mean time to surgery was 33.2 days; 21.4% of patients who underwent surgery improved in AIS grade at discharge (p = 0.030). Overall, the only factor associated with improvement in neurological status was undergoing surgery (p = 0.03) and shorter time to surgery (p = 0.02).

CONCLUSIONS

This is the first study to describe the management and outcomes of spinal trauma in East Africa. Due to the lack of referral hospitals, patients are admitted late after trauma, often with severe neurological deficit. Surgery is performed but generally late in the course of hospital stay. The decision to perform surgery and timing are heavily influenced by the availability of implants and economic factors such as insurance status. Patients with incomplete deficits who may benefit most from surgery are not prioritized. The authors’ results suggest that surgery may have a positive impact on patient outcome. Further studies with a larger sample size are needed to confirm our results. These results provide strong support to implement evidence-based protocols for the management of spinal trauma.
Cortical bone trajectory screws used to save failed traditional trajectory screws in the osteoporotic lumbar spine and vice versa: a human cadaveric biomechanical study
Authors: Zhang Ren-Jie , Li Hui-Min , Gao Hai , Jia Chong-Yu , Xing Tao , Dong Fu-Long , Shen Cai-Liang
Published: April 2019

OBJECTIVE

Traditional trajectory (TT) screws are widely used in lumbar fixation. However, they may require revision surgery in some instances, especially in patients with osteoporotic spines. Cortical bone trajectory (CBT) screws may potentially be used to rescue a failed TT screw and vice versa in nonosteoporotic spines. This study aimed to investigate whether a CBT screw can salvage a compromised TT screw in osteoporotic lumbar spines and vice versa.

METHODS

A total of 42 vertebrae from 17 cadaveric lumbar spines were obtained. Bone mineral density was measured, and a CBT screw was randomly inserted into one side of each vertebra. A TT screw was then inserted into the contralateral side. The biomechanical properties of the screws were tested to determine their insertional torque, pullout strength, and fatigue performance. After checking the screws for the failure of each specimen, the failed screw track was salvaged with a screw of the opposite trajectory. The specimen was then subjected to the same mechanical tests, and results were recorded. A repeat pullout test on TT and CBT screws was also performed.

RESULTS

When CBT screws were used to rescue failed TT screws, the original torque increased by 50%, an average of 81% of the pullout strength of the initial TT screws was retained, and the fatigue performance was equal to that of the original screws, which were considerably stronger than the loose TT screws—that is, the TT repeat screws/TT screws were 33% of the pullout strength of the initial TT screws. When the TT screws were used to salvage the compromised CBT screws, the TT screws retained 51% of the original torque and 54% of the original pullout strength, and these screws were still stronger than the loose CBT screws—that is, the loose CBT screws retained 12% pullout strength of the initial CBT screws. Fatigue performance and the ratio of the pullout strength considerably decreased between the CBT rescue screws and the original CBT screws but slightly changed between the TT rescue screws and the original TT screws.

CONCLUSIONS

CBT and TT screws can be applied in a revision technique to salvage each other in osteoporotic lumbar spines. Additionally, CBT and TT screws each retain adequate insertional torque, pullout strength, and fatigue performance when used for revision in osteoporotic lumbar spines.
Ten-year analysis of saccular aneurysms in the Barrow Ruptured Aneurysm Trial
Authors: Spetzler Robert F. , McDougall Cameron G. , Zabramski Joseph M. , Albuquerque Felipe C. , Hills Nancy K. , Nakaji Peter , Karis John P. , Wallace Robert C.
Published: April 2019

OBJECTIVE

The authors present the 10-year results of the Barrow Ruptured Aneurysm Trial (BRAT) for saccular aneurysms. The 1-, 3-, and 6-year results of the trial have been previously reported, as have the 6-year results with respect to saccular aneurysms. This final report comparing the safety and efficacy of clipping versus coiling is limited to an analysis of those patients presenting with subarachnoid hemorrhage (SAH) from a ruptured saccular aneurysm.

METHODS

In the study, 362 patients had saccular aneurysms and were randomized equally to the clipping and the coiling cohorts (181 each). The primary outcome analysis was based on the assigned treatment group; poor outcome was defined as a modified Rankin Scale (mRS) score > 2 and was independently adjudicated. The extent of aneurysm obliteration was adjudicated by a nontreating neuroradiologist.

RESULTS

There was no statistically significant difference in poor outcome (mRS score > 2) or deaths between these 2 treatment arms during the 10 years of follow-up. Of 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. After the initial hospitalization, 2 of 241 (0.8%) clipped saccular aneurysms and 23 of 115 (20%) coiled saccular aneurysms required retreatment (p < 0.001). At the 10-year follow-up, 93% (50/54) of the clipped aneurysms were completely obliterated, compared with only 22% (5/23) of the coiled aneurysms (p < 0.001). Two patients had documented rebleeding, both died, and both were in the assigned and treated coiled cohort (2/83); no patient in the clipped cohort (0/175) died (p = 0.04). In 1 of these 2 patients, the hemorrhage was not from the target aneurysm but from an incidental basilar artery aneurysm, which was coiled at the same time.

CONCLUSIONS

There was no significant difference in clinical outcomes between the 2 assigned treatment groups as measured by mRS outcomes or deaths. Clinical outcomes in the patients with posterior circulation aneurysms were better in the coiling group at 1 year, but after 1 year this difference was no longer statistically significant. Rates of complete aneurysm obliteration and rates of retreatment favored patients who actually underwent clipping compared with those who underwent coiling.

Clinical trial registration no.: NCT01593267 (clinicaltrials.gov)