Surgeons perform better with eye movement training

ScienceDaily (Nov. 30, 2011) — Surgeons can learn their skills more quickly if they are taught how to control their eye movements. Research led by the University of Exeter shows that trainee surgeons learn technical surgical skills much more quickly and deal better with the stress of the operating theatre if they are taught to mimic the eye movements of experts.

This research, published in the journal Surgical Endoscopy, could transform the way in which surgeons are trained to be ready for the operating theatre.

Working in collaboration with the University of Hong Kong, the Royal Devon and Exeter NHS Foundation Trust and the Horizon training centre Torbay, the University of Exeter team identified differences in the eye movements of expert and novice surgeons. They devised a gaze training programme, which taught the novices the 'expert' visual control patterns. This enabled them to learn technical skills more quickly than their fellow students and perform these skills in distracting conditions similar to the operating room.

Thirty medical students were divided into three groups, each undertaking a different type of training. The 'gaze trained' group of students was shown a video, captured by an eye tracker, displaying the visual control of an experienced surgeon. The footage highlighted exactly where and when the surgeon's eyes were fixed during a simulated surgical task. The students then conducted the task themselves, wearing the same eye-tracking device. During the task they were encouraged to adopt the same eye movements as those of the expert surgeon.

Students learned that successful surgeons 'lock' their eyes to a critical location while performing complex movements using surgical instruments. This prevents them from tracking the tip of the surgical tool, helping them to be accurate and avoid being distracted.

After repeating the task a number of times, the students' eye movements soon mimicked those of a far more experienced surgeon. Members of the other groups, who were either taught how to move the surgical instruments or were left to their own devices, did not learn as quickly. Those students' performance broke down when they were put into conditions that simulated the environment of the operating theatre and they needed to multi-task.

Dr Samuel Vine of the University of Exeter explained: "It appears that teaching novices the eye movements of expert surgeons allows them to attain high levels of motor control much quicker than novices taught in a traditional way. This highlights the important link between the eye and hand in the performance of motor skills. These individuals were also able to successfully multi-task without their technical skills breaking down, something that we know experienced surgeons are capable of doing in the operating theatre.

"Teaching eye movements rather than the motor skills may have reduced the working memory required to complete the task. This may be why they were able to multi-task whilst the other groups were not."

Dr Samuel Vine and Dr Mark Wilson from Sport and Health Sciences at the University of Exeter have previously worked with athletes to help them improve their performance through gaze training, but this is the first study to examine the benefits of gaze training in surgical skills training.

Dr Vine added: "The findings from our research highlight the potential for surgical educators to 'speed up' the initial phase of technical skill learning, getting trainees ready for the operating room earlier and therefore enabling them to gain more 'hands on' experience. This is important against a backdrop of reduced government budgets and new EU working time directives, meaning that in the UK we have less money and less time to deliver specialist surgical training."

The research team is now analysing the eye movements of surgeons performing 'real life' operations and are working to develop a software training package that will automatically guide trainees to adopt surgeons eye movements.

Mr John McGrath, Consultant Surgeon at the Royal Devon and Exeter Hospital, said: "The use of simulators has become increasingly common during surgical training to ensure that trainee surgeons have reached a safe level of competency before performing procedures in the real-life operating theatre. Up to now, there has been fairly limited research to understand how these simulators can be used to their maximum potential.

"This exciting collaboration with the Universities of Exeter and Hong Kong has allowed us to trial a very novel approach to surgical education, applying the team's international expertise in the field of high performance athletes. Focussing on surgeons' eye movements has resulted in a reduction in the time taken to learn specific procedures and, more importantly, demonstrated that their skills are less likely to break down under pressure. Our current work has now moved into the operating theatre to ensure that patients will benefit from the advances in surgical training and surgical safety."

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Aggression prevents the better part of valor ... in fig wasps

ScienceDaily (Dec. 1, 2011) — Researchers have confirmed a unique behaviour within the male population of tiny fig wasps that pollinate fig trees -- they team up to help pregnant females, even if they have not mated themselves.

Published online in the Royal Society journal Biology Letters, the study confirms that placid male pollinator fig wasps work together to chew an escape tunnel for their females, before crawling back into the fig to die -- the non-pollinating variety are too busy fighting each other to help.

"Male insects can cooperate to attract the attention of females or to ensure that they are successful in mating, but I don't know of any other male insects which exhibit post-mating teamwork like this," says Dr Steve Compton from the Faculty of Biological Sciences.

Fig trees are vital for rainforest ecosystems. Producing fruit all year, more birds and animals feed on them than on any other plant in the rainforest. There are more than 850 types of fig tree, each pollinated by a single uniquely adapted type of fig wasp.

The research team examined some 60,000 individual fig flowers in the laboratory, each containing either pollinating fig wasps or parasitic fig wasps. All figs contained many females but alongside these, some contained a single male and others contained several males.

The hatched young of both types mate with each other before the females attempt to escape, leaving the males to die inside the fig. "Neither type of fig wasp female is strong enough to make their own way out, so they need help from the males to do this," says Dr Compton.

Escape rates for pollinator wasps were consistently high and increased when more males were present. When only one parasitic fig wasp was present, it was just as successful as the pollinators in chewing an escape route after mating, but when several males were present, the success rates plummeted.

The study also suggests that the ability of males to cooperate is hampered by innate aggression. Of the two groups of fig wasps -- those that pollinate fig trees and non-pollinators, which are parasites of the tree -- only the parasitic wasps fight more for the right to mate with females, and this group were far less able to work together.

"It would seem that male parasitic fig wasps are unable to switch off the hard-wired aggression needed to successfully mate to cooperate with each other, even when their genetic investment is at stake," says Dr Compton. "Pollinators' teamwork may be prompted because of the likelihood of genetic connection to the mated females, but the parasitic fig wasps were in the same situation."

Dr Compton believes the successful collaboration between the pollinating male fig wasps studied is likely to be normal for all pollinator fig wasps. He hopes to study a highly aggressive species of pollinators, where males fight intensely, often to death. "This will shed light on whether the cooperation is present in all pollinators, or if aggressive behaviour is too difficult to switch off after mating," he says.

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Nazia Suleman, Shazia Raja, and Stephen G. Compton. Only pollinator fig wasps have males that collaborate to release their females from figs of an Asian fig tree. Biol. Lett., November 30, 2011 DOI: 10.1098/rsbl.2011.1016

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Less invasive anesthetic methods better for endovascular aneurysm repair

ScienceDaily (Oct. 27, 2011) — Researchers have identified a safer, more cost effective way to provide anesthesia for patients undergoing endovascular repair of an abdominal aortic aneurysm -- a common, often asymptomatic condition that, if not found and treated, can be deadly.

A new study done by investigators at Wake Forest Baptist Medical Center found that using less invasive spinal, epidural and local/monitored anesthesia care (MAC) is better than general anesthesia for elective endovascular repair of infrarenal abdominal aortic aneurysms (EVAR).

Details of the research appear in the November issue of the Journal of Vascular Surgery, the official publication of the Society for Vascular Surgery.

Aortic aneurysms are abnormal bulges, or "ballooning" in the walls of the aorta, the body's largest artery. Roughly the diameter of a garden hose, this artery brings oxygen-rich blood from the heart to the rest of the body. It extends from the heart down through the chest and abdominal region, where it divides into a blood vessel that supplies each leg. Although an aneurysm can develop anywhere along the aorta, most occur in the section running through the abdomen (abdominal aneurysms). An infrarenal abdominal aortic aneurysm is one that occurs in the belly, below the kidney arteries.

Occasionally an aneurysm may occur because of an area of weakness within the artery wall. An aortic aneurysm is serious because it may rupture, causing life-threatening internal bleeding. The risk of an aneurysm rupturing increases as the aneurysm gets larger. Each year, approximately 15,000 Americans die of a ruptured aortic aneurysm, however the condition is usually asymptomatic until the point of rupture. As such, most aortic aneurysms are unexpectedly identified while a patient is having a computed tomography (CT) scan or ultrasound done for another condition. Men over the age of 65 with a history of ever smoking can have an ultrasound done to specifically screen for aneurysms as part of a "Welcome-to-Medicare" visit with their physician. When detected in time, an aortic aneurysm can usually be repaired with surgery.

Infrarenal abdominal aortic aneurysms make up about 95 percent or more of abdominal aortic aneurysms and, while they occur in both sexes, they are most prevalent in men older than 60, affecting about 3 percent of this population, explained study co-author Matthew S. Edwards, B.A., M.S., M.D., a professor of vascular and endovascular surgery and public health sciences at Wake Forest Baptist.

"That's a lot of people," Edwards said. "If aortic aneurysms aren't repaired, they can burst and 80 to 90 percent of people who have a ruptured aortic aneurysm die. It's necessary for those who are suitable candidates for surgery to have their aneurysms repaired."

EVAR has completely revolutionized the care of aneurysms, allowing doctors to do repairs through two small incisions in the groin, Edwards said. It is currently the most common procedure for repairing aortic aneurysms in the United States. Historic trends have led to general anesthesia being the most common mode of anesthesia used for this procedure, but it is sometimes associated with the development of pneumonia, the need for a breathing tube and other pulmonary complications, he explained.

Other anesthetic techniques can also be used, such as local anesthesia, local anesthesia plus sedation (called "monitored" or "MAC"), spinal anesthesia and epidural anesthesia. According to this study, these other methods result in a shortened hospital stay and fewer pulmonary complications.

"In our study, general anesthesia was associated with increased postoperative length of stay (LOS) and increased complications involving the lungs when compared to the other anesthetic methods," Edwards said.

The researchers collected data on 6,009 patients who had elective EVAR performed between 2005 to 2008 at one of 221 North American hospitals. General anesthesia was used in 4,868 of the cases, while 419 patients had spinal anesthesia during their procedure; 331 had epidural anesthesia; and 391 had local/MAC. Emergency cases and patients who had other procedures being done at the same time that required general anesthesia were excluded from the study.

The team then reviewed the data to evaluate rates of mortality, morbidity and length of stay (LOS), or how long the patient remained in the hospital after the procedure.

The researchers found that general anesthesia was associated with an increase in pulmonary complications when compared to spinal and local/MAC anesthesia. Use of general anesthesia also was associated with a 10 percent increase in LOS for general when compared to spinal anesthesia, and a 20 percent increase when compared to general versus local/MAC anesthesia. Trends toward increased pulmonary complications and LOS were not observed for general versus epidural anesthesia. No significant association between anesthesia type and mortality was observed.

"Our study data suggest that increasing the use of less invasive anesthetic techniques, when appropriate, may limit postoperative complications in EVAR patients," Edwards said.

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Matthew S. Edwards, Jeanette S. Andrews, Angela F. Edwards, Racheed J. Ghanami, Matthew A. Corriere, Philip P. Goodney, Christopher J. Godshall, Kimberley J. Hansen. Results of endovascular aortic aneurysm repair with general, regional, and local/monitored anesthesia care in the American College of Surgeons National Surgical Quality Improvement Program database. Journal of Vascular Surgery, 2011; 54 (5): 1273 DOI: 10.1016/j.jvs.2011.04.054

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Building better HIV antibodies: Biologists create neutralizing antibody that shows increased potency

ScienceDaily (Oct. 27, 2011) — Using highly potent antibodies isolated from HIV-positive people, researchers have recently begun to identify ways to broadly neutralize the many possible subtypes of HIV. Now, a team led by biologists at the California Institute of Technology (Caltech) has built upon one of these naturally occurring antibodies to create a stronger version they believe is a better candidate for clinical applications.

Current advances in isolating antibodies from HIV-infected individuals have allowed for the discovery of a large number of new, broadly neutralizing anti-HIV antibodies directed against the host receptor (CD4) binding site -- a functional site on the surface of the virus that allows for cell entry and infection. Using a technique known as structure-based rational design, the team modified one already-known and particularly potent antibody -- NIH45-46 -- so that it can target the binding site in a different and more powerful way. A study outlining their process was published in the Oct. 27 issue of Science Express.

"NIH45-46 was already one of the most broad and potent of the known anti-HIV antibodies," says Pamela Bjorkman, Max Delbrück Professor of Biology at Caltech and senior author on the study. "Our new antibody is now arguably the best of the currently available, broadly neutralizing anti-HIV antibodies."

By conducting structural studies, the researchers were able to identify how NIH45-46 interacted with gp120 -- a protein on the surface of the virus that's required for the successful entry of HIV into cells -- to neutralize the virus. Using this information, they were able to create a new antibody (dubbed NIH45-46G54W) that is better able to grab onto and interfere with gp120. This improves the antibody's breadth -- or extent to which it effectively targets many subtypes of HIV -- and potency by an order of magnitude, according to Ron Diskin, a postdoctoral scholar in Bjorkman's lab at Caltech and the paper's lead author.

"Not only did we design an improved version of NIH45-46, our structural data are calling into question previous assumptions about how to make a vaccine in order to elicit such antibodies," says Diskin. "We hope that these observations will help to guide and improve future immunogen design."

By improving the efficacy of antibodies that can neutralize HIV, the researchers point to the possibility of clinical testing for NIH45-46G54W and other antibodies as therapeutic agents. It's also plausible that understanding effective neutralization by powerful antibodies may be useful in vaccine development.

"The results uncover the structural underpinnings of anti-HIV antibody breadth and potency, offer a new view of neutralization by CD4-binding site anti-HIV antibodies, and establish principles that may enable the creation of a new group of HIV therapeutics," says Bjorkman, who is also a Howard Hughes Medical Institute investigator.

Other Caltech authors on the study, "Increasing the Potency and Breadth of an HIV Antibody by Using Structure-Based Rational Design," include Paola M. Marcovecchio, Anthony P. West, Jr., Han Gao, and Priyanthi N.P. Gnanapragasm. Johannes Scheid, Florian Klein, Alexander Abadir, and Michel Nussenweig from Rockefeller University, and Michael Seaman from Beth Israel Deaconess Medical Center in Boston also contributed to the paper. The research was funded by the Bill & Melinda Gates Foundation, the National Institutes of Health, the Gordon and Betty Moore Foundation, and the German Research Foundation.

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The above story is reprinted from materials provided by California Institute of Technology. The original article was written by Katie Neith.

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Ron Diskin, Johannes F. Scheid, Paola M. Marcovecchio, Anthony P. West, Jr., Florian Klein, Han Gao, Priyanthi N. P. Gnanapragasam, Alexander Abadir, Michael S. Seaman, Michel C. Nussenzweig, Pamela J. Bjorkman. Increasing the Potency and Breadth of an HIV Antibody by Using Structure-Based Rational Design. Science, Published online Oct. 27, 2011 DOI: 10.1126/science.1213782

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