A simple little sticker could soon be saving the lives of patients recovering from gastrointestinal surgery. The clever device is designed to detect the presence of leaking digestive fluids sooner than otherwise possible.
When surgeons close up an incision in an organ such as the stomach, intestine or pancreas, there's always a risk that digestive fluids will start leaking out of the wound before it fully heals.
According to Dr. Chet Hammill from Washington University School of Medicine in St. Louis, there's a 30% chance of the patient spending the next six months in hospital if such leaks aren't caught soon enough. There's also a 20% chance that they will die.
Making matters worse, conventional ultrasound scans aren't sufficient to spot the problem, due to the fact that they can't reliably differentiate between digestive fluids and other bodily fluids such as blood.
That's where the BioSUM comes in.
Its name an acronym for "Bioresorbable, Shape-adaptive, Ultrasound-readable Materials," the device was created by Northwestern University's Prof. John A. Rogers and postdoctoral fellow Jiaqi Liu. Dr. Hammill initiated the study, and led the evaluation of the prototype.
The BioSUM takes the form of a thin, flexible, biocompatible sticker, made up of several spaced-apart metal discs embedded in a pH-responsive hydrogel base. It simply gets adhered to the organ in question, near the incision site, before the patient is closed up.
As long as no leakages occur, the BioSUM stays in its default state.
If digestive fluids do start leaking out, however, the resulting climb in acidity around the incision causes the sticker's hydrogel base to expand. As it expands, it forces the metal discs farther apart. This telltale change in disc spacing can be imaged via an ultrasound scan, with a little help from custom image-analysis software.
In Dr. Hammill's tests, the BioSUM predictably responded to pH changes within just a few minutes, and could be imaged by ultrasound even when implanted 10 cm (3.9 in) deep into pigs' bodies.
And importantly, the BioSUM does not have to be removed from the patient's body, as it harmlessly dissolves after about one month. As an added bonus, the hydrogel can be tweaked to respond to the unique acidity of different types of digestive fluids, so it can be optimized for use on specific organs.
In fact, the scientists are now adapting the technology for the detection of other post-surgical complications such as internal bleeding or temperature changes caused by infections.
"The majority of operations in the abdomen – when you have to remove something and sew it back together – carry a risk of leaking. We can’t fully prevent those complications, but maybe we can catch them earlier to minimize harm," said Hammill. "Even if we could detect a leak 24 or 48 hours earlier, we could catch complications before the patient becomes really sick. This new technology has potential to completely change the way we monitor patients after surgery."
A paper on the research was recently published in the journal Science. You can see a BioSUM in all its expanding glory, in the video below.
Sources: Northwestern University, American Association for the Advancement of Science via EurekAlert
