Success Story
Early Warning System for Abdominal Leaks
Critical Care
How visual sensor technology allows continuous monitoring after gastrointestinal surgery.
The SensAL project addresses the problem of anastomotic leaks following gastrointestinal surgery. Worldwide, around 14 million procedures of this type are performed every year. When surgeons remove diseased tissue—for example, due to cancer or inflammatory bowel disease—they reconnect the healthy tissue through an anastomosis. Unfortunately, about 10 percent of these reconnections fail to heal, resulting in leaks. These leaks allow bacteria and digestive fluids to enter the abdominal cavity, which can lead to serious complications such as sepsis.
Inge Herrmann is professor at the University of Zurich and ETH Zurich and leads research groups at the Balgrist University Hospital and Empa. She has worked with clinicians all her life. The PHRT funding was a great opportunity to bring this new sensor into clinical practice. As a first step, Herrmann’s group developed an adhesive technology with integrated sensors to support wound healing and alert doctors of complications. However, because of its implantable nature, this technology is currently in the late preclinical stage, and clinical applications remain a few years away.
To provide patients with an intermediate solution, extracorporeal sensors were created that can be placed in the wound drainage bags used postoperatively. These drains collect fluid from the surgical site. Currently, clinicians must check them manually. This process is time-consuming and provides only sporadic readings.
The newly developed sensor allows for continuous monitoring without the need for electronic components. It changes color when biomarkers indicate a leak, which can be picked up by the naked eye. This can then trigger further diagnostics, such as a CT scan, to either confirm or rule out an abdominal leak. The sensor thus acts as an early warning system for clinicians to detect leaks before sepsis develops.
“It was really impressive how excited the clinicians were”, Herrmann says. “Sample collection is usually a very tedious process because someone needs to collect samples every day, including on weekends. You have to be careful not to miss a single one. I’m really delighted that we have not missed any samples so far, which confirms the strong interest in the technology from the clinical side.”
The results look very promising. “Our preliminary data show that SensAL can offer high-resolution yet very affordable patient monitoring. It provides clinicians with an early warning that a patient is about to develop a complication”, she says.
“Our preliminary data show that SensAL can offer a highresolution yet very affordable patient monitoring.”
The team has so far collected around 1,000 patient samples and analyzed more than 250. To date, all measurements have been carried out offline. The clinical application of this technology is currently being pursued in a joint project with the Cleveland Clinic in Ohio, USA, and with several hospitals in Europe. An upcoming Bridge Discovery project, an initiative of Innosuisse and SNSF, will finance the manufacturing of these sensors on a large scale.
Herrmann is optimistic about the future. As the sensor is affordable, safe and does not require additional resources, it has been very well received by clinicians. Discussions about a potential spin-off to support implementation are already underway.