Orin Bloch, Langston T. Holly, Jongsoo Park, Chinyere Obasi, Kee Kim, and J. Patrick Johnson
Object. In recent studies some authors have indicated that 20% of patients have at least one ectatic vertebral artery (VA) that, based on previous criteria in which preoperative computerized tomography (CT) and standard intraoperative fluoroscopic techniques were used, may prevent the safe placement of C1–2 transarticular screws. The authors conducted this study to determine whether frameless stereotaxy would improve the accuracy of C1–2 transarticular screw placement in healthy patients, particularly those whom previous criteria would have excluded.
Methods. The authors assessed the accuracy of frameless stereotaxy for C1–2 transarticular screw placement in 17 cadaveric cervical spines. Preoperatively obtained CT scans of the C-2 vertebra were registered on a stereotactic workstation. The dimensions of the C-2 pars articularis were measured on the workstation, and a 3.5-mm screw was stereotactically placed if the height and width of the pars interarticularis was greater than 4 mm. The specimens were evaluated with postoperative CT scanning and visual inspection. Screw placement was considered acceptable if the screw was contained within the C-2 pars interarticularis, traversed the C1–2 joint, and the screw tip was shown to be within the anterior cortex of the C-1 lateral mass.
Transarticular screws were accurately placed in 16 cadaveric specimens, and only one specimen (5.9%) was excluded because of anomalous VA anatomy. In contrast, a total of four specimens (23.5%) showed significant narrowing of the C-2 pars interarticularis due to vascular anatomy that would have precluded atlantoaxial transarticular screw placement had previous nonimage-guided criteria been used.
Conclusions. Frameless stereotaxy provides precise image guidance that improves the safety of C1–2 transarticular screw placement and potentially allows this procedure to be performed in patients previously excluded because of the inaccuracy of nonimage-guided techniques.
Maria Pia Tropeano, Riccardo Spaggiari, Hernán Ileyassoff, Kee B. Park, Angelos G. Kolias, Peter J. Hutchinson, and Franco Servadei
Traumatic brain injury (TBI) is a global public health problem and more than 70% of trauma-related deaths are estimated to occur in low- and middle-income countries (LMICs). Nevertheless, there is a consistent lack of data from these countries. The aim of this work is to estimate the capacity of different and heterogeneous areas of the world to report and publish data on TBI. In addition, we wanted to estimate the countries with the highest and lowest number of publications when taking into account the relative TBI burden.
First, a bibliometric analysis of all the publications about TBI available in the PubMed database from January 1, 2008, to December 31, 2018, was performed. These data were tabulated by country and grouped according to each geographical region as indicated by the WHO: African Region (AFR), Region of the Americas (PAH), South-East Asia Region (SEAR), European Region (EUR), Eastern Mediterranean Region (EMR), and Western Pacific Region (WPR). In this analysis, PAH was further subdivided into Latin America (AMR-L) and North America (AMR-US/Can). Then a “publication to TBI volume ratio” was derived to estimate the research interest in TBI with respect to the frequency of this pathology.
Between 2008 and 2018 a total of 8144 articles were published and indexed in the PubMed database about TBI. Leading WHO regions in terms of contributions were AMR-US/Can with 4183 articles (51.36%), followed by EUR with 2003 articles (24.60%), WPR with 1507 (18.50%), AMR-L with 141 articles (1.73%), EMR with 135 (1.66%), AFR with 91 articles (1.12%), and SEAR with 84 articles (1.03%). The highest publication to TBI volume ratios were found for AMR-US/Can (90.93) and EUR (21.54), followed by WPR (8.71) and AMR-L (2.43). Almost 90 times lower than the ratio of AMR-US/Can were the ratios for AFR (1.15) and SEAR (0.46).
An important disparity currently exists between countries with a high burden of TBI and those in which most of the research is conducted. A call for improvement of data collection and research outputs along with an increase in international collaboration could quantitatively and qualitatively improve the ability of LMICs to ameliorate TBI care and develop clinical practice guidelines.
Gail Rosseau, Walter D. Johnson, Kee B. Park, Miguel Arráez Sánchez, Franco Servadei, and Kerry A. Vaughan
Since the creation of the World Health Organization (WHO) in 1948, the annual World Health Assembly (WHA) has been the major forum for discussion, debate, and approval of the global health agenda. As such, it informs the framework for the policies and budgets of many of its Member States. For most of its history, a significant portion of the attention of health ministers and Member States has been given to issues of clean water, vaccination, and communicable diseases. For neurosurgeons, the adoption of WHA Resolution 68.15 changed the global health landscape because the importance of surgical care for universal health coverage was highlighted in the document. This resolution was adopted in 2015, shortly after the publication of The Lancet Commission on Global Surgery Report titled “Global Surgery 2030: evidence and solutions for achieving health, welfare and economic development.” Mandating global strengthening of emergency and essential surgical care and anesthesia, this resolution has led to the formation of surgical and anesthesia collaborations that center on WHO and can be facilitated via the WHA. Participation by neurosurgeons has grown dramatically, in part due to the official relations between WHO and the World Federation of Neurosurgical Societies, with the result that global neurosurgery is gaining momentum.
Saksham Gupta, Monty Khajanchi, Vineet Kumar, Nakul P. Raykar, Blake C. Alkire, Nobhojit Roy, and Kee B. Park
Traumatic brain injury (TBI) is a global epidemic with an increasing incidence in low- and middle-income countries (LMICs). The time from arrival at the hospital to receiving appropriate treatment (“third delay”) can vary widely in LMICs, although its association with mortality in TBI remains unknown.
A retrospective cohort analysis with multivariable logistic regression was conducted using the Toward Improved Trauma Care Outcomes in India database, which contains data from 4 urban trauma centers in India from 2013–2015.
There were 6278 TBIs included in the cohort. The patients’ median age was 39 years (interquartile range 27–52 years) and 80% of patients were male. The most frequent mechanisms of injury were road traffic accidents (52%) and falls (34%). A majority of cases were transfers from other facilities (79%). In-hospital 30-day mortality was 27%; of patients who died, 21% died within 24 hours of arrival. The median third delay was 10 minutes (interquartile range 0–60 minutes); 34% of cases had moderate third delay (10–60 minutes) and 22% had extended third delay (≥ 61 minutes). Overall 30-day mortality was associated with moderate third delay (OR 1.3, p = 0.001) and extended third delay (OR 1.3, p = 0.001) after adjustment by pertinent covariates. This effect was pronounced for 24-hour mortality: moderate and extended third delays were independently associated with ORs of 3.4 and 3.8, respectively, for 24-hour mortality (both p < 0.001).
Third delay is associated with early mortality in patients with TBI, and represents a target for process improvement in urban trauma centers.
Ji Hoon Phi, Sun Ha Paek, Hyun-Tai Chung, Sang Soon Jeong, Chul-Kee Park, Hee-Won Jung, and Dong Gyu Kim
The current study was undertaken to evaluate the tumor control rate and functional outcome after Gamma Knife surgery (GKS) in patients with a trigeminal schwannoma. The conditions associated with the development of cranial neuropathies after radiosurgery were scrutinized.
The authors reviewed the clinical records and radiological data in 22 consecutive patients who received GKS for a trigeminal schwannoma. The median tumor volume was 4.1 ml (0.2–12.0 ml), and the mean tumor margin dose was 13.3 ± 1.3 Gy at an isodose line of 49.9 ± 0.6% (mean ± standard deviation). The median clinical follow-up period was 46 months (range 24–89 months), and the median length of imaging follow-up was 37 months (range 24–79 months).
Tumor growth control was achieved in 21 (95%) of the 22 patients. Facial pain responded best to radio-surgery, with two thirds of patients showing improvement. However, only one third of patients with facial hypesthesia improved. Six patients (27%) experienced new or worsening cranial neuropathies after GKS. Ten patients (46%) showed tumor expansion after radiosurgery, and nine of these also showed central enhancement loss. Loss of central enhancement, tumor expansion, and a tumor in a cavernous sinus were found to be significantly related to the emergence of cranial neuropathies.
The use of GKS to treat trigeminal schwannoma resulted in a high rate of tumor control and functional improvement. Cranial neuropathies are bothersome complications of radiosurgery, and tumor expansion in a cavernous sinus after radiosurgery appears to be the proximate cause of the complication. Loss of central enhancement could be used as a warning sign of cranial neuropathies, and for this vigilant patient monitoring is required.
Martin Andreas Lehre, Lars Magnus Eriksen, Abenezer Tirsit, Segni Bekele, Saba Petros, Kee B. Park, Marianne Lundervik Bøthun, and Knut Wester
The objective of this study was to investigate epidemiology and outcome after surgical treatment for spinal injuries in Ethiopia.
Medical records of patients who underwent surgery for spine injuries at Myungsung Christian Medical Center in Addis Ababa, Ethiopia, between January 2008 and September 2012 were reviewed retrospectively. Assessment of outcome and complications was determined from patient consultations and phone interviews.
A total of 146 patients were included (129 males, 17 females). Their mean age was 31.7 years (range 15–81 years). The leading cause of injury was motor vehicle accidents (54.1%), and this was followed by falls (26.7%). The most common injury sites were lumbar (41.1%) and cervical (34.2%) regions of the spine. In 21.2% of patients, no neurological deficit was present before surgery, 46.6% had incomplete spinal cord injury (American Spinal Injury Association [ASIA] Impairment Scale [AIS] Grade B-D), and 32.2% had complete spinal cord injury (AIS Grade A). Follow-up was hampered by suboptimal infrastructure, but information regarding outcome was successfully obtained for 110 patients (75.3%). At follow-up (mean 22.9 months; range 2–57 months), 25 patients (17.1%) were confirmed dead and 85 patients (58.2%) were alive; 49 patients (33.6%) underwent physical examination. At least 8 of the 47 patients (17.0%) with a complete injury and 29 of the 68 patients (42.6%) with an incomplete injury showed neurological improvement. The reported incidences of pressure wounds, recurrent urinary tract infections, pneumonia, and thromboembolic events were 22.5%, 13.5%, 5.6%, and 1.1%, respectively.
Patients showed surprisingly good recovery considering the limited resources. Surgical treatment for spine injuries in Ethiopia is considered beneficial.
Michael C. Dewan, Abbas Rattani, Graham Fieggen, Miguel A. Arraez, Franco Servadei, Frederick A. Boop, Walter D. Johnson, Benjamin C. Warf, and Kee B. Park
Worldwide disparities in the provision of surgical care result in otherwise preventable disability and death. There is a growing need to quantify the global burden of neurosurgical disease specifically, and the workforce necessary to meet this demand.
Results from a multinational collaborative effort to describe the global neurosurgical burden were aggregated and summarized. First, country registries, third-party modeled data, and meta-analyzed published data were combined to generate incidence and volume figures for 10 common neurosurgical conditions. Next, a global mapping survey was performed to identify the number and location of neurosurgeons in each country. Finally, a practitioner survey was conducted to quantify the proportion of disease requiring surgery, as well as the median number of neurosurgical cases per annum. The neurosurgical case deficit was calculated as the difference between the volume of essential neurosurgical cases and the existing neurosurgical workforce capacity.
Every year, an estimated 22.6 million patients suffer from neurological disorders or injuries that warrant the expertise of a neurosurgeon, of whom 13.8 million require surgery. Traumatic brain injury, stroke-related conditions, tumors, hydrocephalus, and epilepsy constitute the majority of essential neurosurgical care worldwide. Approximately 23,300 additional neurosurgeons are needed to address more than 5 million essential neurosurgical cases—all in low- and middle-income countries—that go unmet each year. There exists a gross disparity in the allocation of the surgical workforce, leaving large geographic treatment gaps, particularly in Africa and Southeast Asia.
Each year, more than 5 million individuals suffering from treatable neurosurgical conditions will never undergo therapeutic surgical intervention. Populations in Africa and Southeast Asia, where the proportion of neurosurgeons to neurosurgical disease is critically low, are especially at risk. Increasing access to essential neurosurgical care in low- and middle-income countries via neurosurgical workforce expansion as part of surgical system strengthening is necessary to prevent severe disability and death for millions with neurological disease.
Michael C. Dewan, Abbas Rattani, Rania Mekary, Laurence J. Glancz, Ismaeel Yunusa, Ronnie E. Baticulon, Graham Fieggen, John C. Wellons III, Kee B. Park, and Benjamin C. Warf
Hydrocephalus is one of the most common brain disorders, yet a reliable assessment of the global burden of disease is lacking. The authors sought a reliable estimate of the prevalence and annual incidence of hydrocephalus worldwide.
The authors performed a systematic literature review and meta-analysis to estimate the incidence of congenital hydrocephalus by WHO region and World Bank income level using the MEDLINE/PubMed and Cochrane Database of Systematic Reviews databases. A global estimate of pediatric hydrocephalus was obtained by adding acquired forms of childhood hydrocephalus to the baseline congenital figures using neural tube defect (NTD) registry data and known proportions of posthemorrhagic and postinfectious cases. Adult forms of hydrocephalus were also examined qualitatively.
Seventy-eight articles were included from the systematic review, representative of all WHO regions and each income level. The pooled incidence of congenital hydrocephalus was highest in Africa and Latin America (145 and 316 per 100,000 births, respectively) and lowest in the United States/Canada (68 per 100,000 births) (p for interaction < 0.1). The incidence was higher in low- and middle-income countries (123 per 100,000 births; 95% CI 98–152 births) than in high-income countries (79 per 100,000 births; 95% CI 68–90 births) (p for interaction < 0.01). While likely representing an underestimate, this model predicts that each year, nearly 400,000 new cases of pediatric hydrocephalus will develop worldwide. The greatest burden of disease falls on the African, Latin American, and Southeast Asian regions, accounting for three-quarters of the total volume of new cases. The high crude birth rate, greater proportion of patients with postinfectious etiology, and higher incidence of NTDs all contribute to a case volume in low- and middle-income countries that outweighs that in high-income countries by more than 20-fold. Global estimates of adult and other forms of acquired hydrocephalus are lacking.
For the first time in a global model, the annual incidence of pediatric hydrocephalus is estimated. Low- and middle-income countries incur the greatest burden of disease, particularly those within the African and Latin American regions. Reliable incidence and burden figures for adult forms of hydrocephalus are absent in the literature and warrant specific investigation. A global effort to address hydrocephalus in regions with the greatest demand is imperative to reduce disease incidence, morbidity, mortality, and disparities of access to treatment.
Swagoto Mukhopadhyay, Maria Punchak, Abbas Rattani, Ya-Ching Hung, James Dahm, Serena Faruque, Michael C. Dewan, Sophie Peeters, Sonal Sachdev, and Kee B. Park
In 2000, the global density of neurosurgeons was estimated at 1 per 230,000 population, which remains the most recent estimate of the global neurosurgeon workforce density. In 2004, the World Health Organization (WHO) estimated that there were 33,193 neurosurgeons worldwide, including trainees. There have been no updates to this estimate in the past decade. Moreover, only WHO region–level granularity regarding neurosurgeon distribution exists; country-level estimates are limited. The neurosurgery workforce is a crucial component to meeting the growing burden of neurosurgical diseases, which not only represent high absolute incidences and prevalences, but also represent correspondingly high disability-adjusted life years affecting hundreds of millions of people worldwide. Combining the lack of knowledge about the availability of the neurosurgical workforce and the increasing demand for neurosurgical services underscores the need for a system of neurosurgical workforce density surveillance.
This study involved 3 key steps: 1) global survey/literature review to obtain the number of working neurosurgeons per WHO-recognized country, 2) regression to interpolate any missing data, and 3) calculation of workforce densities and comparison to available historical data by WHO region.
Data for 198 countries were collected (158) or interpolated (40). The global total number of neurosurgeons was estimated at 49,940. Overall, neurosurgeon density ranged from 0 to 58.95 (standardized to per 1,000,000 population) with a median of 3.56 (IQR 0.29–8.26). Thirty-three countries were found to have no neurosurgeons (zero). The highest density, 58.95, was in Japan, where 7495 neurosurgeons are taking care of a population of 127,131,800.
In 2015, the Lancet Commission on Global Surgery estimated that 143 million additional surgical procedures are needed in low- and middle-income countries each year, and a subsequent study revealed that approximately 15% of those surgical procedures are neurosurgical. Based on our results, we can conclude that there are approximately 49,940 neurosurgeons currently, worldwide. The availability of neurosurgeons appears to have increased in all geographic regions over the past decade, with Southeast Asia experiencing the greatest growth. Such remarkable expansion should be assessed to determine factors that could play a role in other regions where the acceleration of growth would be beneficial.