Posts tagged surgery
Articles and news from the latest research reports.
Anaesthetic technique important to prevent damage to brain
Researchers at the University of Adelaide have discovered that a commonly used anaesthetic technique to reduce the blood pressure of patients undergoing surgery could increase the risk of starving the brain of oxygen.
Reducing blood pressure is important in a wide range of surgeries - such as sinus, shoulder, back and brain operations - and is especially useful for improving visibility for surgeons, by helping to remove excess blood from the site being operated on.
There are many different techniques used to lower patients’ blood pressure for surgery - one of them is known as hypotensive anaesthesia, which slows the arterial blood pressure by up to 40%.
Professor PJ Wormald, a sinus, head and neck surgeon from the University’s Discipline of Surgery, based at the Queen Elizabeth Hospital, led a world-first study looking at both the effectiveness of hypotensive anaesthesia from the surgeon’s point of view and its impact on the patients.
The study followed 32 patients who underwent endoscopic sinus surgery. The results have now been published online in the journal The Laryngoscope.
"There is an important balance in anaesthesia where the blood pressure is lowered so that the surgeon has good visibility and is able to perform surgery safely. There are numerous sensitive areas in sinus surgery - the brain, the eye and large vessels such as the carotid. However, if the blood pressure is lowered too far this may cause damage to the brain and other organs," says Professor Wormald.
"We know from previous research that a person’s brain undergoing anaesthesia has lower metabolic requirements than the awake brain, and therefore it can withstand greater reductions in blood flow.
"There is also a widely accepted concept that the brain has the ability to autoregulate - to adapt and maintain a constant blood flow as needed, despite a wide range of blood pressure conditions. Our studies challenge this; they show that the brain can only autoregulate up to a point, and cannot completely adapt to such low blood pressures.
"This drop in blood pressure poses a risk of starving the brain of much-needed oxygen and nutrients, which could result in injury. There have been cases, for example, where patients have reported memory loss following surgery.
"Given that hypotensive anaesthesia is a widely used technique, not just in sinus surgery but in many different types of surgery, we’ve made recommendations in our paper that suggest a safer approach to this technique. This would reduce risk to the patient while enabling the surgeon to carry out their work effectively," Professor Wormald says.
(Image: Shutterstock)
Man’s chronic runny nose was actually brain fluid leaking
Arizona had one of the worst allergy seasons in recent memory this year. Even people who normally don’t suffer found themselves with itchy eyes and runny noses.
Thankfully it’s only a couple months out of the year, but for one valley man, he had year-round allergy symptoms. A runny nose all the time.
He was shocked to find out after years of suffering, his runny nose was really a leaking brain.
Joe Nagy first noticed it when he sat up to get out of bed.
"Brooop! This clear liquid dribbled out of my nose like tears out of your eyes. I go what is this?"
A runny nose that got worse.
"Once or twice a week. Then pretty soon it was all the time."
He started taking allergy medicine, but the runny nose didn’t stop.
"I got to the point where I had tissues all the time. in my pocket full of tissues always had them all folded up."
He still remembers the embarrassing moments when he couldn’t get to the tissues in time, like when he was picking up blueprints for his model airplanes.
"It was about a teaspoon full. Splashed all over the top sheet… I said, these damn allergies. I was embarrassed as hell."
Fed up with the runny nose, Joe went to a specialist to test that fluid dripping out of his nose and found out it wasn’t a runny nose. It was leaking brain fluid.
"I was scared to death if you want to know the truth."
The membrane surrounding Joe’s brain had a hole in it and his brain fluid was leaking out.
"You don’t really think about it, but our brains are really just above our noses all of the time," says Barrow Neurological Institute neurosurgeon Peter Nakaji.
"This is one of the more common conditions to be missed for a long time… because so many people have runny noses."
Joe was ready to have brain surgery to fix the leak. When he got a near-deadly case of meningitis, that brain fluid became infected.
"Some people come in with meningitis and at first they have to be treated to stop the infection itself. Then as soon as the infection is under control we repair the leak."
You might wonder how Joe could have brain fluid leaking out of his nose for a year and a half. Wouldn’t the brain dry out?
Each day our bodies produce about 12 ounces of brain fluid, give or take. Producing enough to keep the brain bathed in liquid.
"These leaks can be very very tiny, a little like a puncture on a bicycle tire, that sometimes you have trouble even finding where it is."
Dr. Nakaji eventually found the leak.
"If you look right here you can see a little tiny hole. You see a little bit of what looks like running water."
Dr. Nakaji showed us how this problem is fixed with surgery.
"Nowadays we do quite a bit of surgery on the brain and base of brain through the nose. We never have to cut up into the brain. We’re getting a needle up into the space to check it out, and then to put a little bit of glue. This is just a bit of cartilage from the nose that we can get to repair over it and then the body will seal it up."
Joe wasn’t convinced it would work. After all, he’d been dealing with the problem for so long. But days after the surgery, they removed the gauze from his nose.
"I was waiting for the dribble. This leaking cause I was so used to it every day. I got my hankie. Nothing. It’s never come back."
What has come back is his desire to work on the hobbies he loves, like his model airplanes. And bigger projects.
"Now I’m going to build a sailboat and the sailboat I’m building is called a Great Pelican."
And after all he’s been through, Joe feels pretty confident this boat won’t leak.
Before you call a brain surgeon about your runny nose, Dr. Nakaji says it most likely is just a runny nose. Brain fluid, it’s different than a runny nose caused by allergies in that the liquid is very, very clear.
So if you have a chronic runny nose, start with an allergist or an ear, nose and throat specialist. They can perform a simple test to determine if it’s a typical runny nose or something more serious.
The causes of this type of leak can be numerous. Sometimes a past head injury can lead to brain fluid leaking, or it can be caused from complications of a spinal tap or surgery.
A 30cm (1ft) snake slowly moves through the body of a man on a spotless table, advancing its way around the liver. It stops, sniffs to the left, then turns to the right and slithers behind the ribcage.
This is a medical robot, guided by a skilled surgeon and designed to get to places doctors are unable to reach without opening a patient up. It is still only a prototype and has not yet been used on real patients - only in the lab. But its designers, from OC Robotics in Bristol, are convinced that once ready and approved, it could help find and remove tumours.
The mechanical snake is one of several groundbreaking cancer technologies showcased at previous week’s International Conference on Oncological Engineering at the University of Leeds.
A syndrome called “post-operative cognitive decline” has been coined to refer to the commonly reported loss of cognitive abilities, usually in older adults, in the days to weeks after surgery. In fact, some patients time the onset of their Alzheimer’s disease symptoms from a surgical procedure. Exactly how the trio of anesthesia, surgery, and dementia interact is clinically inconclusive, yet of great concern to patients, their families and physicians.
A year ago, researchers at the Perelman School of Medicine at the University of Pennsylvania reported that Alzheimer’s pathology, as reflected by cerebral spinal fluid biomarkers, might be increased in patients after surgery and anesthesia. However, it is not clear whether the anesthetic drugs or the surgical procedure itself was responsible. To separate these possibilities, the group turned to a mouse model of Alzheimer’s disease.
The results, published online this month in the Annals of Surgery, show that surgery itself, rather than anesthesia, has the more profound impact on a dementia-vulnerable brain.
Having an operation?
Don’t be surprised if the surgeon performs it from the room next door.
Indeed, he could even operate from halfway across the world — because these doctors are increasingly using robots to treat disease and injury.
‘These are incredibly exciting times,’ says Brian Davies, emeritus professor of medical robotics at Imperial College London and inventor of the surgical robot, which in April 1991 became the first in the world to remove tissue from a living human.
‘Robots can work much more accurately than human hands, which is fantastic now that we are seeking minimally invasive surgery through a tiny incision where precision is key,’ says Professor Davies.
Of course, the surgeon still performs the operation, but uses the robot to see inside the body, or operates it using a joystick or console so it’s like a spare arm — but without the human hand’s natural shake.
‘Medical robots are not like the sci-fi images of autonomous humanoids; they are sophisticated computer-assisted instruments that remain always under the surgeon’s control,’ says Dr Patrick Finlay, founder of medical robotics firm MediMaton.