A congenital condition called pectus excavatum, in which a child’s breastbone is sunken into the chest, can be corrected through minimally invasive surgery, but pain control after the operation can be a challenge. A Mayo Clinic study has found an effective way to control pain and reduce opioid painkiller use after surgery: sending children home with catheters that infuse a non-narcotic nerve-blocking drug called a paravertebral blockade. Use of the blocks shortens hospital stays and reduces opioid use after surgery, the researchers discovered.
The study focused on pain control after children receive a Nuss procedure, in which small incisions are made and a stainless steel or titanium bar is placed under the sternum to reshape the chest wall. Researchers looked at the cases of 132 children who had Nuss surgery from 2010 through 2015. Of those, 114 received paravertebral catheters and continued receiving the infusions for two to five days after returning home. Eighteen were instead given an epidural.
Use of paravertebral catheters cut the median hospital stay by roughly a day and a half from 120 hours to 80 hours, the researchers found. Opioid painkiller consumption also decreased. Opioids can have significant side effects that slow recovery after surgery, including drowsiness, light-headedness, nausea, constipation and risk of falls.
‘Our operation is minimally invasive, but it produces major changes in the chest wall. Pain was an issue for our patients, but this new technique has solved the problem. It’s better than an epidural, because it’s reliable, and kids can go home with it. For the first time, we consistently deliver on our promise to minimize pain,’ says co-author Christopher Moir, M.D., a pediatric and thoracic surgeon in the Mayo Clinic Children’s Center.
Chest wall deformities are fairly common. Pectus excavatum, also called funnel chest, is the most frequent. The sunken breastbone is noticeable when a child is born and typically worsens during the adolescent growth spurt. Even mild cases can cause children to feel self-conscious. Severe cases can interfere with heart and lung function.
Epidurals have been a standard method to manage pain after pectus excavatum surgery, but they are stopped before children leave the hospital, and severe pain may persist after that. Many hospitals, including Mayo Clinic, have been using other options, such as nerve blocks, patient-controlled painkiller delivery and non-narcotic painkiller injections. There has been little consistent data on pain outcomes.
‘This study puts solid data to what we see each day in the hospital and what families tell us. Paravertebal catheters work,’ Dr. Moir says.

Mayo Clinichttp://tinyurl.com/zqbbaz5

Radiation-induced breast cancer risk from digital mammography is low for the majority of women, but risk is higher in women with large breasts, who received 2.3 times more radiation and required more views per examination to image as much of the breast as possible compared to those with small or average-sized breasts.
The study also found that screening every two years instead of annually, and beginning at age 50 instead of 40 or 45, lowers the likelihood of radiation-induced breast cancer in all women. The findings from a team of researchers include Rebecca Hubbard, PhD, an associate professor of Biostatistics in Biostatistics and Epidemiology in the Perelman School of Medicine at the University of Pennsylvania.
In eight screening strategies estimated using two models, the group simulated the lifetime risk of women developing radiation-induced breast cancer from digital screening mammography and dying from the disease compared to the number of deaths averted through early detection.
The group found that screening 100,000 women, ages 50 to 74, every two years, prevented 627 deaths. The radiation exposure from these screening exams, and any subsequent diagnostic work-ups, caused 27 breast cancer cases and 4 breast cancer deaths. Although screening 100,000 women annually from 40 to 74 years prevented 968 deaths, it also raised cancer risk five-fold, causing 100 additional radiation-induced breast cancers and 12 additional breast cancer deaths compared with screening every two years from age 50 to 74.
Recommendations released recently by the U.S. Preventive Services Task Force, an independent panel appointed by the federal government, echo the study’s finding that women between the ages of 50 and 74 should be screened once every two years for breast cancer.
‘Choosing a screening schedule that reduces harms while maintaining the benefits of more frequent screening makes screening mammography safer for all women,’ Hubbard, who is also senior author on the study, said. ‘As our understanding of the effects of individual characteristics on harms and benefits of mammography grows, we can more effectively tailor screening strategies to minimize harms and save more lives.’
While not explicitly reviewed in the research, the findings suggest risk is also higher in those with breast implants, which require twice as many views during mammography, and/or denser breasts which require additional evaluations resulting in more radiation exposure.
The study also noted that obtaining fewer mammograms would also result in fewer false positives, which can prevent radiation exposure from possibly unneeded follow-up diagnostic mammograms.

Perelman School of Medicine http://tinyurl.com/jqfej6z

Rice University students have created a prototype of a device to monitor the pulse and oxygen levels of a fetus undergoing endoscopic fetal surgery in a mother’s womb.
The WombOx team of senior engineering students worked in close collaboration with the Texas Children’s Fetal Center to create their device, which miniaturizes the components found in a pulse oximeter commonly clipped to a patient’s finger in a doctor’s office.
Pulse oximeters ‘see’ oxygen levels in the blood by comparing light from a source to the light that reaches a detector on the other side of the finger. The instrument can calculate oxygen saturation by how much light it senses is absorbed by the tissue.
That kind of information hasn’t been available to doctors working to help fetuses suffering from congenital defects such as spina bifida, the incomplete closure of the backbone around the spinal cord.
Texas Children’s Hospital is pioneering efforts to treat such conditions through the endoscopic procedure known as fetoscopic surgery. During surgery, doctors are able to monitor the health of a fetus through ultrasound, but that only gives them a basic heartbeat. Knowing oxygen levels in the blood is critical when doctors need to act quickly to help a fetus in distress, and the WombOx device shows potential for providing such data in real time.
To build the prototype, the bioengineering students, Claudia Iriondo, Thomas Loughlin, Samir Saidi and Kathryn Wallace, worked closely with Dr. Magdalena Sanz Cortes, an associate professor of obstetrics and gynecology at Baylor College of Medicine and a clinician at the Texas Children’s Pavilion for Women, as well as their Rice faculty adviser, engineering lecturer Eric Richardson. It is the product of their capstone design project, required of most senior engineering students at Rice.
A few weeks after winning the top Willy Revolution Award, a $5,000 prize presented at Rice’s annual Engineering Design Showcase for innovation in design, and days before commencement, the team spent a morning in a device-testing suite at the Pavilion for Women to watch their prototype in action.
‘This project was challenging because of the size of the instruments that we work with,’ Sanz Cortes said. ‘When we started talking about the whole project, we talked about the size of a pulse oximeter. Transforming that into the size of the device they have created is very challenging.
‘The other challenging part was the mechanics, how to design something that is safe enough for the baby and can be compatible with our surgeries. It’s not a trivial matter, and they did a great job,’ she said.
At first glance, the device is a loop of wire on a hollow stick. But a closer look reveals that the wire is a special hybrid that expands to a predetermined shape at the correct temperature. It carries LEDs and a photodetector on miniature circuit boards that illuminate and sense the flow of blood through the tissue underneath.
The loop is packaged in a retractable sheath that fits through the small incision made in fetoscopic surgeries. The WombOx device is used like all other endoscopic tools, with a miniature camera. The idea is to insert the tube into the mother’s womb and extend the loop. Once it expands, doctors use the video feed to guide the loop around a limb and gently tighten it, putting the sensors in place to monitor the fetus throughout the surgical procedure.
‘Our design, like other endoscopic tools, is intended for single use,’ Iriondo explained. The device is durable enough to withstand unsheathing, expansion in the womb, attachment to the fetus and resheathing during removal.’

Rice University http://tinyurl.com/z3p6dmc

Computational modelling makes it possible to predict the onset and progression of knee osteoarthritis in overweight people, shows a new study from the University of Eastern Finland. A computational model based on the degradation of the collagen fibril network in the articular cartilage was able to predict the onset and progression of osteoarthritis in overweight people during a four-year follow-up. In normal-weight people, osteoarthritis did not develop within this time span.

The study also developed a model of the knee joint which makes it possible to evaluate the mechanical responses experienced by cartilage cells in healthy and osteoarthritic cartilage during daily activities such as walking. The model demonstrated that both menisectomy and osteoarthritic changes to the cartilage cause significant alterations in cartilage cell responses.

Osteoarthritis is a joint disease estimated to affect around 5% of the total world population. Osteoarthritis is the most common in the knee or hip joint and it often develops as a result of ageing, but it can also develop due to excessive loading or joint injury. In Europe, over 100 million people have arthritis, and in America, direct costs of arthritis were $51.1 billion in 2004. In addition, it has been predicted that the number of patients with knee osteoarthritis increases by 40% by the end of 2050.

Osteoarthritis proceeds gradually, weakening the articular cartilage and ultimately wearing it off completely from the ends of articulating bones. In these cases, the patient suffers from heavy joint pain and the joint becomes stiff, often leading to incapacity for work. Joint replacement surgery is the only effective treatment for osteoarthritis, which is why the prevention of osteoarthritis would be a cost-effective alternative both for the patient and society at large.

The study utilised a computational modelling method integrating the tissue and cellular levels of the articular cartilage in order to analyse the function of the articular cartilage during the onset and progression of osteoarthritis. The method simulated the effect of articular cartilage composition, structure and various loadings on the volume, shape and mechanical responses of cartilage cells.

Compared to healthy cartilage, the cell volume of osteoarthritic cartilage increased as a result of mechanical loading. The modelling indicated that the most important explanatory factors for the cell volume increase were the pericellular fixed charge density, i.e. the number of proteoglycan molecules, and the stiffness of the collagen fibril network.

The study also analysed the effect of menisectomy, a commonly used method in knee surgery, and simulated overweight on cell responses. Both menisectomy and simulated overweight substantially increased fluid pressures in the cell and cartilage tissue during walking, but they did not have an effect on the cell shape or volume in healthy cartilage. In osteoarthritic cartilage, however, cells were compressed and elongated more, probably due to altered cartilage integrity.

During standing, the strains were amplified more in the cell than in pericellullar tissue in healthy joint cartilages, but the opposite was observed in osteoarthritic joint cartilage. It is possible that the pericellular tissue’s function is to protect cartilage cells from sudden changes and to promote cartilage health.

The study also developed computational algorithms for the degradation of the collagen fibril network in the articular cartilage and its reorganisation in order to predict the development and progression of osteoarthritis caused by overweight and cartilage damage. The estimate obtained from the degradation algorithm was well in line with the clinically observed progression of osteoarthritis during a four-year follow-up. Furthermore, the collagen fibril network structure in the mechanically injured cartilage was observed to be disorganised in the vicinity of the injury, suggesting that a cartilage injury exposes cartilage to further damage.

In-depth understanding of the effects of abnormal loading, early osteoarthritis and mechanical injuries on cellular and tissue responses in cartilage makes it possible to develop new strategies for the recognition, prevention and slowing down the progression of the disease. The methods developed in the study may become widespread in specialised health care in the future. However, rigorous clinical validation will be necessary before they can be introduced to clinical use.

University of Eastern Finlandwww.uef.fi/-/computational-modelling-can-predict-onset-and-progression-of-knee-osteoarthritis-in-overweight-people