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Michael A. Silva, Alfred P. See, Hormuzdiyar H. Dasenbrock, Nirav J. Patel and Mohammad A. Aziz-Sultan

OBJECTIVE

Patients with paraclinoid aneurysms commonly present with visual impairment. They have traditionally been treated with clipping or coiling, but flow diversion (FD) has recently been introduced as an alternative treatment modality. Although there is still initial aneurysm thrombosis, FD is hypothesized to reduce mass effect, which may decompress the optic nerve when treating patients with visually symptomatic paraclinoid aneurysms. The authors performed a meta-analysis to compare vision outcomes following clipping, coiling, or FD of paraclinoid aneurysms in patients who presented with visual impairment.

METHODS

A systematic literature review was performed using the PubMed and Web of Science databases. Studies published in English between 1980 and 2016 were included if they reported preoperative and postoperative visual function in at least 5 patients with visually symptomatic paraclinoid aneurysms (cavernous segment through ophthalmic segment) treated with clipping, coiling, or FD. Neuroophthalmological assessment was used when reported, but subjective patient reports or objective visual examination findings were also acceptable.

RESULTS

Thirty-nine studies that included a total of 2458 patients (520 of whom presented with visual symptoms) met the inclusion criteria, including 307 visually symptomatic cases treated with clipping (mean follow-up 26 months), 149 treated with coiling (mean follow-up 17 months), and 64 treated with FD (mean follow-up 11 months). Postoperative vision in these patients was classified as improved, unchanged, or worsened compared with preoperative vision. A pooled analysis showed preoperative visual symptoms in 38% (95% CI 28%–50%) of patients with paraclinoid aneurysms. The authors found that vision improved in 58% (95% CI 48%–68%) of patients after clipping, 49% (95% CI 38%–59%) after coiling, and 71% (95% CI 55%–84%) after FD. Vision worsened in 11% (95% CI 7%–17%) of patients after clipping, 9% (95% CI 2%–18%) after coiling, and 5% (95% CI 0%–20%) after FD. New visual deficits were found in patients with intact baseline vision at a rate of 1% (95% CI 0%–3%) for clipping, 0% (95% CI 0%–2%) for coiling, and 0% (95% CI 0%–2%) for FD.

CONCLUSIONS

To the authors’ knowledge, this is the first meta-analysis to assess vision outcomes after treatment for paraclinoid aneurysms. The authors found that 38% of patients with these aneurysms presented with visual impairment. These data also demonstrated a high rate of visual improvement after FD without a significant difference in the rate of worsened vision or iatrogenic visual impairment compared with clipping and coiling. These findings suggest that FD is an effective option for treatment of visually symptomatic paraclinoid aneurysms.

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Nicole A. Silva, Belinda Shao, Michael J. Sylvester, Jean Anderson Eloy and Chirag D. Gandhi

OBJECTIVE

Observation and neurosurgical intervention for unruptured intracranial aneurysms (UIAs) in the elderly population is rapidly increasing. Cerebral aneurysm coiling (CACo) is favored over cerebral aneurysm clipping (CAC) in elderly patients, yet some elderly individuals still undergo CAC. The cost-effectiveness of treating UIAs requires further exploration. Understanding the effect of intervention on hospital charges and length of stay (LOS) as well as perioperative mortality and complications can further shed light on its economic impact. The purpose of this study was to analyze the cost and perioperative outcomes of UIAs in elderly patients (≥ 65 years of age) after CACo or CAC intervention.

METHODS

Retrospective cohorts of CACo and CAC admissions were extracted from National (Nationwide) Inpatient Sample data obtained between 2002 and 2013, forming parallel intervention groups to compare the following outcomes between elderly and nonelderly patients: average LOS and mean hospital admission costs, in-hospital mortality, and complications. Covariates included sex, race or ethnicity, and comorbidities.

RESULTS

Elderly patients undergoing CAC experienced an average LOS of 8.0 days, whereas elderly patients undergoing CACo stayed an average of 3.2 days. The mean hospital charges incurred during admission totaled $95,960 in the elderly patients who underwent CAC versus $87,960 in the ones who underwent CACo. Elderly patients in whom CAC was performed had a 2.2% rate of in-hospital mortality, with a 2.6 greater adjusted odds of in-hospital mortality than nonelderly patients treated with CAC. In contrast, elderly patients who underwent CACo had a 1.36 greater adjusted odds of in-hospital mortality than their nonelderly counterparts. Compared to nonelderly patients receiving both interventions, elderly individuals had a significantly higher prevalence of various comorbidities and incidence of complications. Elderly patients who received CAC experienced a 10.3% incidence rate of perioperative stroke, whereas their CACo counterparts experienced this complication at a rate of 3.5%. Elderly patients treated with CAC had greater odds of perioperative acute renal failure, whereas their CACo counterparts had greater odds of perioperative deep venous thrombosis and pulmonary embolism.

CONCLUSIONS

Intervention with CAC and CACo in the elderly is resource intensive and is associated with higher risk than in the nonelderly. Those deciding between intervention and conservative management should consider these risks and costs, especially the 2.2% postoperative mortality rate associated with CAC in the elderly population. Further comparative cost-effectiveness research is needed to weigh these costs and outcomes against those of conservative management.

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Kevin T. Huang, Michael A. Silva, Alfred P. See, Kyle C. Wu, Troy Gallerani, Hasan A. Zaidi, Yi Lu, John H. Chi, Michael W. Groff and Omar M. Arnaout

OBJECTIVE

Recent advances in computer vision have revolutionized many aspects of society but have yet to find significant penetrance in neurosurgery. One proposed use for this technology is to aid in the identification of implanted spinal hardware. In revision operations, knowing the manufacturer and model of previously implanted fusion systems upfront can facilitate a faster and safer procedure, but this information is frequently unavailable or incomplete. The authors present one approach for the automated, high-accuracy classification of anterior cervical hardware fusion systems using computer vision.

METHODS

Patient records were searched for those who underwent anterior-posterior (AP) cervical radiography following anterior cervical discectomy and fusion (ACDF) at the authors’ institution over a 10-year period (2008–2018). These images were then cropped and windowed to include just the cervical plating system. Images were then labeled with the appropriate manufacturer and system according to the operative record. A computer vision classifier was then constructed using the bag-of-visual-words technique and KAZE feature detection. Accuracy and validity were tested using an 80%/20% training/testing pseudorandom split over 100 iterations.

RESULTS

A total of 321 total images were isolated containing 9 different ACDF systems from 5 different companies. The correct system was identified as the top choice in 91.5% ± 3.8% of the cases and one of the top 2 or 3 choices in 97.1% ± 2.0% and 98.4 ± 13% of the cases, respectively. Performance persisted despite the inclusion of variable sizes of hardware (i.e., 1-level, 2-level, and 3-level plates). Stratification by the size of hardware did not improve performance.

CONCLUSIONS

A computer vision algorithm was trained to classify at least 9 different types of anterior cervical fusion systems using relatively sparse data sets and was demonstrated to perform with high accuracy. This represents one of many potential clinical applications of machine learning and computer vision in neurosurgical practice.

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Robert Howman-Giles, Michael Besser, Ian H. Johnston and Merle Da Silva

✓ A pineal germinoma in a 9-month-old boy is described. After surgical resection and cerebrospinal fluid diversionary shunting, the child developed hematogenous metastases which showed marked increased uptake on radionuclide gallium-67 scans.

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Michael A. Silva, Alfred P. See, Hormuzdiyar H. Dasenbrock, Ramsey Ashour, Priyank Khandelwal, Nirav J. Patel, Kai U. Frerichs and Mohammad A. Aziz-Sultan

Successful application of endovascular neurosurgery depends on high-quality imaging to define the pathology and the devices as they are being deployed. This is especially challenging in the treatment of complex cases, particularly in proximity to the skull base or in patients who have undergone prior endovascular treatment. The authors sought to optimize real-time image guidance using a simple algorithm that can be applied to any existing fluoroscopy system. Exposure management (exposure level, pulse management) and image post-processing parameters (edge enhancement) were modified from traditional fluoroscopy to improve visualization of device position and material density during deployment. Examples include the deployment of coils in small aneurysms, coils in giant aneurysms, the Pipeline embolization device (PED), the Woven EndoBridge (WEB) device, and carotid artery stents. The authors report on the development of the protocol and their experience using representative cases.

The stent deployment protocol is an image capture and post-processing algorithm that can be applied to existing fluoroscopy systems to improve real-time visualization of device deployment without hardware modifications. Improved image guidance facilitates aneurysm coil packing and proper positioning and deployment of carotid artery stents, flow diverters, and the WEB device, especially in the context of complex anatomy and an obscured field of view.

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Michael A. Silva, Alfred P. See, Priyank Khandelwal, Ashutosh Mahapatra, Kai U. Frerichs, Rose Du, Nirav J. Patel and Mohammad A. Aziz-Sultan

OBJECTIVE

Paraclinoid aneurysms represent approximately 5% of intracranial aneurysms (Drake et al. [1968]). Visual impairment, which occurs in 16%–40% of patients, is among the most common presentations of these aneurysms (Day [1990], Lai and Morgan [2013], Sahlein et al. [2015], and Silva et al. [2017]). Flow-diverting stents, such as the Pipeline Embolization Device (PED), are increasingly used to treat these aneurysms, in part because of their theoretical reduction of mass effect (Fiorella et al. [2009]). Limited data on paraclinoid aneurysms treated with a PED exist, and few studies have compared outcomes of patients after PED placement with those of patients after clipping or coiling.

METHODS

The authors performed a retrospective analysis of 115 patients with an aneurysm of the cavernous to ophthalmic segments of the internal carotid artery treated with clipping, coiling, or PED deployment between January 2011 and March 2017. Postoperative complications were defined as new neurological deficit, aneurysm rupture, recanalization, or other any operative complication that required reintervention.

RESULTS

A total of 125 paraclinoid aneurysms in 115 patients were treated, including 70 with PED placement, 23 with coiling, and 32 with clipping. Eighteen (14%) aneurysms were ruptured. The mean aneurysm size was 8.2 mm, and the mean follow-up duration was 18.4 months. Most aneurysms were discovered incidentally, but visual impairment, which occurred in 21 (18%) patients, was the most common presenting symptom. Among these patients, 15 (71%) experienced improvement in their visual symptoms after treatment, including 14 (93%) of these 15 patients who were treated with PED deployment. Complete angiographic occlusion was achieved in 89% of the patients. Complications were seen in 17 (15%) patients, including 10 (16%) after PED placement, 2 (9%) after coiling, and 5 (17%) after clipping. Patients with incomplete aneurysm occlusion had a higher rate of procedural complications than those with complete occlusion (p = 0.02). The rate of postoperative visual improvement was significantly higher among patients treated with PED deployment than in those treated with coiling (p = 0.01). The significant predictors of procedural complications were incomplete occlusion (p = 0.03), hypertension, (p = 0.04), and diabetes (p = 0.03).

CONCLUSIONS

In a large series in which patient outcomes after treatment of paraclinoid aneurysms were compared, the authors found a high rate of aneurysm occlusion and a comparable rate of procedural complications among patients treated with PED placement compared with the rates among those who underwent clipping or coiling. For patients who presented with visual symptoms, those treated with PED placement had the highest rate of visual improvement. The results of this study suggest that the PED is an effective and safe modality for treating paraclinoid aneurysms, especially for patients who present with visual symptoms.

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Michael K. Morgan, Ian H. Johnston and Merl de Silva

✓ A 17-year-old girl with unilateral blindness and exophthalmos was found to have Bonnet-Dechaume-Blanc syndrome without retinal arteriovenous communications. The arteriovenous malformation was managed by combined intracranial resection, ophthalmic artery ligation, and selective embolization of the external carotid component.

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Philip H. Gutin, Steven A. Leibel, William M. Wara, Ali Choucair, Victor A. Levin, Theodore L. Philips, Pamela Silver, Vasco Da Silva, Michael S. B. Edwards, Richard L. Davis, Keith A. Weaver and Sharon Lamb

✓ The authors report survival data for the first 41 patients treated for recurrent malignant gliomas with interstitial brachytherapy at the University of California, San Francisco (1980–1984). Iodine-125 (125I) sources were temporarily implanted using stereotaxic techniques. The median survival period for 18 patients with recurrent glioblastomas was 52 weeks after brachytherapy; two patients are alive more than 5 years after brachytherapy. The median survival period for 23 patients with recurrent anaplastic astrocytomas is 153 weeks after brachytherapy, with 10 patients alive more than 3 years and four patients alive more than 4 years after brachytherapy. Both groups did significantly better (p < 0.01) than groups of patients with the same diagnoses and similar general characteristics who were treated at recurrence with chemotherapy alone. Because of deterioration of their clinical condition and evidence of recurrence from computerized tomographic scans, 17 (41%) of 41 patients required reoperation 20 to 72 weeks after brachytherapy. Despite the invariable presence of apparently viable tumor cells mixed with necrotic tissue in the resected specimen, nine patients have survived more than 2 years after reoperation and two of the nine are still alive 4 years after reoperation. The authors conclude that brachytherapy with temporarily implanted 125I sources for well-circumscribed, hemispheric, recurrent malignant gliomas is effective and offers a chance for long-term survival even though focal radiation necrosis can seriously degrade the quality of survival in a minority of patients.

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Thiago Augusto Hernandes Rocha, Cyrus Elahi, Núbia Cristina da Silva, Francis M. Sakita, Anthony Fuller, Blandina T. Mmbaga, Eric P. Green, Michael M. Haglund, Catherine A. Staton and Joao Ricardo Nickenig Vissoci

OBJECTIVE

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide, with a disproportionate burden of this injury on low- and middle-income countries (LMICs). Limited access to diagnostic technologies and highly skilled providers combined with high patient volumes contributes to poor outcomes in LMICs. Prognostic modeling as a clinical decision support tool, in theory, could optimize the use of existing resources and support timely treatment decisions in LMICs. The objective of this study was to develop a machine learning–based prognostic model using data from Kilimanjaro Christian Medical Centre in Moshi, Tanzania.

METHODS

This study is a secondary analysis of a TBI data registry including 3138 patients. The authors tested nine different machine learning techniques to identify the prognostic model with the greatest area under the receiver operating characteristic curve (AUC). Input data included demographics, vital signs, injury type, and treatment received. The outcome variable was the discharge score on the Glasgow Outcome Scale–Extended.

RESULTS

The AUC for the prognostic models varied from 66.2% (k-nearest neighbors) to 86.5% (Bayesian generalized linear model). An increasing Glasgow Coma Scale score, increasing pulse oximetry values, and undergoing TBI surgery were predictive of a good recovery, while injuries suffered from a motor vehicle crash and increasing age were predictive of a poor recovery.

CONCLUSIONS

The authors developed a TBI prognostic model with a substantial level of accuracy in a low-resource setting. Further research is needed to externally validate the model and test the algorithm as a clinical decision support tool.