Scientists at the Swiss Federal Laboratories for Materials Science and Technology (EMPA) have developed an advanced surgical sealant that can alert clinicians to the presence of an intestinal leak after gastrointestinal surgery. Such leaks can be very dangerous, but until now clinicians had few ways to detect them before they start causing symptoms. This new polymer patch reacts to pH changes in the presence of leaked intestinal fluid, and produces small bubbles within its structure in response, often within minutes or hours of a leak starting. This physical change in the patch can be visualized using ultrasound or CT scans, allowing clinicians to obtain early warning that stitches in the gut may be leaking. The patch can also change shape in response to intestinal fluid and even release drugs, such as antibiotics, if required.
Performing gastrointestinal surgery can lead to leaks of intestinal fluid into the abdominal cavity, causing a serious risk for patients. Stitches can become leaky over time, but clinicians may not be aware of this until it causes a potentially life-threatening issue for their patient. “Surgeons have told us that they keep a close eye on the surgical field during even the most complicated procedures — but as soon as the abdominal cavity is closed, they are “blind” and may not notice leaks until it is too late,” said Alex Anthis, a researcher involved in the study.
To address this, these researchers have created a surgical patch that can alert clinicians to leaks without having to reopen the surgical site. The stretchy and flexible material contains carbonates within a polyacrylamide matrix. When the patch is exposed to gastrointestinal fluid, the carbonates within convert into gaseous carbon dioxide, creating small bubbles within the structure of the patch.
This change can be seen using a conventional hand-held ultrasound probe, and it also affects the contrast properties of the patch as viewed on a CT scan. This means that gastrointestinal surgery patients could undergo routine follow ups with an ultrasound or CT to ensure that their stitches are still intact within their abdomen.
An additional functionality comes in the form of shape changing properties, whereby the patch can change shape from a circle to a ring shape in the presence of gastrointestinal fluid, which could help clinicians to readily identify the leaky status of the stitches during a CT scan. This was achieved by including an insoluble tantalum oxide compound in the patch, which induces the shape change.
See a video about the patch below.
Study in journal Advanced Science: Surgical Sealant with Integrated Shape?Morphing Dual Modality Ultrasound and Computed Tomography Sensors for Gastric Leak Detection