Using 3D printed models for planning and guidance during endovascular intervention: a technical advance.

Three-dimensional (3D) printing applications in medicine have been limited due to high cost and technical difficulty of creating 3D printed objects. It is not known whether patient-specific, hollow, small-caliber vascular models can be manufactured with 3D printing, and used for small vessel endoluminal testing of devices. Manufacture of anatomically accurate, patient-specific, small-caliber arterial models was attempted using data from a patient's CT scan, free open-source software, and low-cost Internet 3D printing services. Prior to endovascular treatment of a patient with multiple splenic artery aneurysms, a 3D printed model was used preoperatively to test catheter equipment and practice the procedure. A second model was used intraoperatively as a reference. Full-scale plastic models were successfully produced. Testing determined the optimal puncture site for catheter positioning. A guide catheter, base catheter, and microcatheter combination selected during testing was used intraoperatively with success, and the need for repeat angiograms to optimize image orientation was minimized. A difficult and unconventional procedure was successful in treating the aneurysms while preserving splenic function. We conclude that creation of small-caliber vascular models with 3D printing is possible. Free software and low-cost printing services make creation of these models affordable and practical. Models are useful in preoperative planning and intraoperative guidance.

Temporary distal balloon occlusion for hepatic embolization: a novel technique to treat what cannot be selected.

PURPOSE: Particle embolotherapy for liver cancers, such as chemoembolization and yttrium-90 radioembolization, depends on microcatheter selection of the treatment vessel for injection of the embolic. Individually selecting vessels with a microcatheter can be time-consuming and difficult, especially when multiple branches are present in the treatment zone. This article describes a technique to perform an "inverse" embolization-protection of the selected vessel and embolization of the unselected vessels-a technique that has not yet been described. MATERIALS AND METHODS: Two cases of hepatic chemoembolization that would require subselection of multiple branch vessels using conventional technique are reported. In both cases the proper hepatic artery was selected with a soft, nondissecting neurovascular guide catheter. The nontarget hepatic vessel was selected with a neurovascular microcatheter occlusion balloon, and the balloon was inflated to protect that vessel. Embolization to multiple target vessels was then achieved by way of a single injection through the guide catheter. RESULTS: Both procedures were technically successful without complication. Postembolization angiography confirmed normal parenchymal enhancement in the protected zone and expected paucity of enhancement in the treated zone. CONCLUSION: Temporary distal balloon occlusion is a useful technique to treat multiple artery branches with a single injection in cases where individual selection of the branches is difficult or time-consuming. Further study of this technique is warranted.

Emergency Physicians Research Common Problems in Proportion to their Frequency.

INTRODUCTION: Emergency medicine (EM) organizations such as the Society for Academic Emergency Medicine and the Institute of Medicine have called for more clinical research as a way of addressing the scarcity of research in EM. Previous investigations have examined funding and productivity in EM research, but whether EM researchers preferentially concentrate on certain patient-related topics is not known. We hypothesized that at least part of the scarcity of EM research is from the tendency of EM researchers, like researchers in other fields, to focus on rarer conditions with higher morbidity or mortality instead of on more common conditions with less acuity. This study compared the frequency of specific medical conditions presenting to emergency departments nationwide with the frequency of emergency physician research on those same conditions. METHODS: This study is a structured retrospective review and comparison of 2 databases during an 11-year span. Principal diagnoses made by emergency physicians as reported by the National Hospital Ambulatory Medical Care Survey were compared to all first-author publications by emergency physicians as reported in PubMed between 1996 and 2006. Statistics included correlations and linear regression with the number of emergency department (ED) visits per diagnosis as the independent variable and the number of articles published as the dependent variable. RESULTS: During the study period, there was significant concordance between the frequency of presenting conditions in the emergency department and the frequency of research being performed on those conditions, with a high correlation of 0.85 (P < 0.01). More common ED diagnoses such as injury/poisoning, symptoms/ill-defined conditions, and diseases of the respiratory system accounted for 60.9% of ED principal diagnoses and 50.2% of the total research published in PubMed. CONCLUSION: Unlike researchers in other fields, emergency physicians investigate clinical problems in almost the exact proportion as those conditions are encountered in the emergency department. The scarcity of EM research does not have to do with a skewed focus toward less common patient problems.

Percutaneous vertebroplasty and kyphoplasty for pathologic vertebral fractures in the Medicare population: safer and less expensive than open surgery.

PURPOSE: To compare cost and outcomes of surgical and percutaneous treatments of pathologic vertebral fractures. MATERIALS AND METHODS: Standard Medicare 5% anonymized inpatient files (1999-2009) were retrospectively reviewed. Patients with a diagnosis of vertebral fracture without spinal cord injury and primary or metastatic bony malignancy were divided into percutaneous or surgical groups based on whether they received vertebroplasty/kyphoplasty or surgical treatment. Patients who had no intervention or both interventions were excluded. Cost, length of stay, and type of discharge were examined while controlling for demographic and comorbidity variables. RESULTS: A total of 451 patients were included; 52% received percutaneous treatment and 48% received surgery. Patients treated percutaneously were older (P < .001) and more likely to be female (P = .04). Percutaneous therapy predicted $14,862 less Medicare cost and $13,565 less overall cost (P < .001 for both), and 4.1 fewer inpatient days (P < .001). Patients who underwent surgery had higher odds of death (odds ratio = 3.38, P = .016), discharge to a rehabilitation facility (odds ratio = 3.3, P = .003), and transfer to another inpatient facility (odds ratio = 8.53, P < .001), and lower odds of discharge to home (odds ratio = 0.42, P < .001) and hospice (odds ratio = 0.08, P = .002). CONCLUSIONS: In a Medicare population with bony malignancy and vertebral fractures, percutaneous therapy predicted significantly reduced cost and length of stay versus surgery. Patients who underwent percutaneous therapy were significantly less likely to die, be transferred, or be discharged to rehabilitation facilities, and were more likely to be discharged to home or hospice.

Changes in stroke research productivity: A global perspective.

BACKGROUND: While stroke is the second leading cause of death worldwide, little work has been done to quantify the growth and progress of stroke publications. The purpose of this study is to quantitatively analyze trends in the stroke literature over the past 12 years, specifically examining changes in worldwide productivity and study methodology. METHODS: The study was a retrospective bibliometric analysis of all stroke articles published between 1996 and 2008 indexed in MEDLINE. Country of origin, MEDLINE-defined methodology, specialty of the first author, and funding sources (for US articles) were recorded. Growth was analyzed by using linear and nonlinear regression. RESULTS: Total articles numbered 32,309 during the study period, with leading global contributors including the United States with 8795 (27.2%) articles, Japan with 2757 (8.5%) articles, and the United Kingdom with 2629 (8.1%) articles. Growth globally and in the United States followed a linear pattern at 209.9 and 56.2 articles per year, respectively (both P < 0.001). Review articles and clinical trials numbered 5932 (18.4%) and 2934 (9.1%), respectively. Clinical trials followed an exponential growth pattern of 7.7% per year (P < 0.001). Regarding specialty influence, pain management and rehabilitation had the largest proportional growth in clinical trials from 4 to 51 articles. CONCLUSIONS: Within the stroke literature, we observed continued growth worldwide, sustained growth in the United States, and a steady increase in the number of clinical trials, especially by pain management and rehabilitation.

Research productivity in neurosurgery: trends in globalization, scientific focus, and funding.

OBJECT: While research is important for the survival, growth, and expansion of neurosurgery, little work has been done to quantify the status and trends of neurosurgical publications. The purpose of this bibliometric study was to quantitatively analyze trends in neurosurgical publications, including changes in worldwide productivity, study methodology, subspecialty topic, and funding. METHODS: This was a retrospective bibliometric study using MEDLINE to record all publications between 1996 and 2009 by first authors affiliated with neurosurgical departments. Country of origin, MEDLINE-defined methodology, study topic, and funding sources (for US articles) were recorded. Linear regression was used to derive growth rates. RESULTS: Total articles numbered 53,425 during the study period, with leading global contributors including the US with 16,943 articles (31.7%) and Japan with 10,802 articles (20.2%). Countries demonstrating rapid growth in productivity included China (121.9 ± 9.98%/year, p < 0.001), South Korea (50.5 ± 4.7%/year, p < 0.001), India (19.4 ± 1.8%/year, p < 0.001), and Turkey (25.3 ± 2.8%/year, p < 0.001). While general research articles, case reports, and review articles have shown steady growth since 1996, clinical trials and randomized controlled trials have declined to 2004 levels. The greatest overall subspecialty growth was seen in spine surgery. Regarding funding, relative contribution of National Institutes of Health (NIH)-funded publications decreased from 30.2% (290 of 959) to 22.5% (356 of 1229) between 1996 and 2009. CONCLUSIONS: Neurosurgical publications demonstrate continued increases in productivity as well as in global expansion, although US contributions remain dominant. Two challenges that the neurosurgical community is facing include the preponderance of case reports and review articles and the relative decline in NIH funding for US neurosurgical publications, as productivity has outpaced government financial support.

Interventional oncology research in the United States: slowing growth, limited focus, and a low level of funding.

PURPOSE: To establish the characteristics of published interventional oncology (IO) research, including the volume, growth, geographic distribution, type of research, and funding patterns, and to determine how IO research compares with overall radiology research. MATERIALS AND METHODS: This retrospective bibliometric analysis of public data was exempt from Institutional Review Board approval. IO articles published between 1996 and 2008 were identified in the National Library of Medicine MEDLINE database. Country of origin, article methodology, study topic, and source of funding were recorded. Growth was analyzed by using linear and nonlinear regression. RESULTS: Total journal articles numbered 3801, including 847 (22.3%) from the United States, 722 (19.0%) from Japan, and 390 (10.3%) from China. World publications grew with a sigmoid (logistic) pattern (predicted maximum of 586.8 articles per year, P < .001). The United States and China also had logistic and slowing growth (maximums of 111.0 and 48.1 articles per year, respectively; both P < .001). Growth was linear in Japan (growth of 3.0 articles per year, P < .001) and exponential and accelerating in Germany, Italy, South Korea, France, and the United Kingdom. The United States produced 187 (36.9%) review articles but only 52 (13.1%) clinical trials. Japan (75, 18.8%) and China (71, 17.8%) both produced more clinical trials than other countries. U.S. IO articles were less likely than general radiology articles to receive funding from government (12.5% vs 23.7%) and nongovernment (15.0% vs 17.0%) sources. Liver cancer articles constituted 2388 (62.8%) of all IO articles. CONCLUSION: IO research is slowing in the United States but growing elsewhere. Japan and China are leaders in clinical trial research. U.S. IO research receives less funding than does overall radiology research. IO research focuses primarily on liver cancer.

Cardiac CT research: exponential growth.

PURPOSE: To evaluate the increase in cardiac x-ray computed tomographic (CT) research and the relative contributions of radiologists and cardiologists. MATERIALS AND METHODS: This observational study of public data was exempt from institutional review board approval. The National Library of Medicine MEDLINE database was searched for articles published between 1996 and 2006 in which CT was used to acquire images of the heart. The date and journal of publication, authors' specialty and country, and article type were recorded. Trends were evaluated by using regression analysis, with P < or = .05 indicating a significant difference. RESULTS: A total of 1270 articles were identified. Basic science research articles, review articles, case reports, and reports of clinical trials constituted 38%, 19%, 11%, and 7% of the total, respectively. The number of journal articles increased 15.4-fold and increased exponentially at a rate of 28% per year (P < .001). An exponential increase was seen in the number of basic science articles (P < .001), review articles (P < .001), case reports (P < .001), and reports of clinical trials (P < .001). Articles from the United States (n = 464), Germany (n = 260), Japan (n = 125), and The Netherlands (n = 76) constituted 72.8% of the world total. Radiologists published more articles (378 vs 319) and more general research articles (143 vs 100) than did cardiologists; however, cardiologists published more case reports (50 vs 29) and clinical trials (22 vs 18) than did radiologists. Cardiologists wrote more articles than did radiologists in the United States (112 vs 95) and Japan (31 vs 22), whereas radiologists wrote more articles than did cardiologists in Germany (126 vs 53) and The Netherlands (34 vs 31). CONCLUSION: Cardiac CT research is increasing exponentially and is conducted primarily in four countries. Both radiologists and cardiologists make important contributions; however, contributions vary according to the research method used and the country in which the study was conducted. Both factors may influence future clinical adoption patterns.

The impact of National Institutes of Health funding on U.S. cardiovascular disease research.

BACKGROUND: Intense interest surrounds the recent expansion of US National Institutes of Health (NIH) budgets as part of economic stimulus legislation. However, the relationship between NIH funding and cardiovascular disease research is poorly understood, making the likely impact of this policy change unclear. METHODS: The National Library of Medicine's PubMed database was searched for articles published from 1996 to 2006, originating from U.S. institutions, and containing the phrases "cardiolog," "cardiovascular," or "cardiac," in the first author's department. Research methodology, journal of publication, journal impact factor, and receipt of NIH funding were recorded. Differences in means and trends were tested with t-tests and linear regression, respectively, with P < or = 0.05 for significance. RESULTS: Of 117,643 world cardiovascular articles, 36,684 (31.2%) originated from the U.S., of which 10,293 (28.1%) received NIH funding. The NIH funded 40.1% of U.S. basic science articles, 20.3% of overall clinical trials, 18.1% of randomized-controlled, and 12.2% of multicenter clinical trials. NIH-funded and total articles grew significantly (65 articles/year, P < 0.001 and 218 articles/year, P < 0.001, respectively). The proportion of articles receiving NIH funding was stable, but grew significantly for basic science and clinical trials (0.87%/year, P < 0.001 and 0.67%/year, P = 0.029, respectively). NIH-funded articles had greater journal impact factors than non NIH-funded articles (5.76 vs. 3.71, P < 0.001). CONCLUSIONS: NIH influence on U.S. cardiovascular research expanded in the past decade, during the period of NIH budget doubling. A substantial fraction of research is now directly funded and thus likely sensitive to budget fluctuations, particularly in basic science research. NIH funding predicts greater journal impact.

Impact of the National Institutes of Health on radiology research.

PURPOSE: To retrospectively quantify the characteristics of published radiology research sponsored by the National Institutes of Health (NIH) and to retrospectively characterize the contribution of the individual NIH institutes. MATERIALS AND METHODS: The National Library of Medicine's PubMed database was searched for all articles published by U.S. radiology departments from 1996 to 2005. Methodology and NIH grant support were recorded for each article. Data were analyzed with linear regression curve estimation, with P < or = .05 indicating a significant difference. RESULTS: Worldwide, 76 838 articles were identified, with 30 156 (39.25%) originating from the United States. The NIH funded 28.36% of clinical trials and 18.58% of U.S. articles overall. The proportion of funded articles increased annually by 1.1% (P < .001) overall, by 3.5% for clinical trials (P < .001), and by 5.2% for multicenter trials (P < .001). By 2005, 54.9% of all clinical trials and 55.6% of multicenter trials were NIH funded. The National Cancer Institute sponsored the most articles (2505 articles; growth, 13.5 articles per year; P = .003), followed by the National Institute of Neurological Disorders and Stroke (1030 articles; growth, 4.7 articles per year; P = .012). The newest NIH institute, the National Institute of Biomedical Imaging and Bioengineering, had the most rapid growth (320 articles; growth, 43.7 articles per year; P = .01). CONCLUSION: The NIH funded less than one-fifth of all U.S. radiology articles, but the proportion of funded articles is increasing, especially for clinical trials, where in 2005 more than half received funding; cancer and neurologic disease research is relatively well funded.

Characteristics and trends of published emergency medicine research.

OBJECTIVES: Despite its importance in improving patient care, the state of published emergency medicine (EM) research is poorly understood. The countries of origin, methodological characteristics, sources of funding, and ongoing trends in this research are unknown. Knowledge of these characteristics has important policy, research, and clinical implications for academic EM. METHODS: The National Library of Medicine's PubMed database was searched for all articles published from 1996 to 2005 that originated from EM departments. The date and journal of publication, country of origin, study methodology, and, in the case of U.S. articles, acknowledgment of National Institutes of Health (NIH) grant support were noted. Journal impact factors of the publishing journal were assigned to each article. The aggregated data were then analyzed for country, journal of origin, and trend. RESULTS: Of the 14,605 articles originating from EM departments, the United States published 8,550 (58.54%), followed by the United Kingdom with 1,222 (8.37%) and Japan with 663 (4.54%). Significant publication growth was detected worldwide (116.6 articles per year; 95% confidence interval = 101.1 to 132.1; p < 0.0001) and in 17 of the top 20 EM research-producing countries. Among published U.S. studies, the NIH funded 388 (4.5%). Of all articles, 6,152 (41.8%) were published in dedicated EM journals. CONCLUSIONS: Emergency medicine research output is increasing worldwide. The United States is the largest producer of EM research, only a small fraction of which is supported by the NIH. The majority of research published by emergency researchers is published in non-EM journals.

Factors associated with academic radiology research productivity.

PURPOSE: To determine factors associated with research productivity among all university radiology departments in the United States. MATERIALS AND METHODS: As an observational study, this was exempt from institutional review board approval. All 47,299 radiology articles from 1996 through 2003 that were indexed in the National Library of Medicine MEDLINE database were studied. Each article was assigned a "publication impact" score based on the impact factor of its source journal. These citations were then matched, along with National Institutes of Health (NIH) extramural grant, residency, fellowship, faculty, and geographic data, to 109 individual medical school radiology departments. Raw citation count was used to measure research quantity, and aggregate publication impact was used to measure quality. Regression analyses were used to compare the relationship between the study variables and research quality and quantity measures on the departmental and individual faculty level. RESULTS: Finalized statistical models accounted for 75%-88% of variance in productivity. NIH funding had a significant and positive association with all measures of research productivity (P < .001), with one article associated with 167,980 dollars in funding and one publication impact unit associated with 83,271 dollars in funding. Large resident program sizes (P < .001) and the presence of fellows (P = .007) also had a significant association. Geographic region, salary, and faculty characteristics had no detectable association. Extrapolations based on these results estimated the cost of annual global radiology research at 907 million dollars, with the U.S. component at at least 417 million dollars. NIH funding accounted for 45% of the U.S. component. CONCLUSION: NIH funding, resident program size, and fellow characteristics are significantly associated with academic research output.

Small bowel obstruction caused by a congenital jejuno-jejuno band in a child.

A case of small bowel obstruction in a 4-year-old boy with pica is described. The child habitually chewed on his plastic toy action figures. Abdominal radiography and endoscopy confirmed the presence of chewed pieces of plastic within the digestive tract. At surgery, the cause of the obstruction was found to be an internal hernia involving a congenital fibrous band connecting 2 segments of the jejunum and unrelated to pica. Intestinal obstruction caused by foreign bodies is extremely rare, and obstruction caused by congenital bands is even more uncommon. This particular variant of a congenital band has not been previously described. Physicians should be aware that congenital bands can cause small bowel obstruction in children and that surgical treatment is required.