New approach to real-time monitoring after pancreatic surgery

Up to 30 per cent of patients suffer from the complication of a so-called postoperative pancreatic fistula following partial removal of the pancreas. Pancreatic enzymes enter the abdominal cavity, which can considerably prolong the inpatient stay and lead to a delay or complete cancellation of the chemotherapy required for pancreatic cancer. The fistula is diagnosed by analysing the digestive enzyme alpha-amylase in the drainage secretions with regard to its biochemical reaction with the storage carbohydrate starch. The enzyme alpha-amylase breaks down the carbohydrate starch into its components. If the tests show high alpha-amylase values, this indicates the presence of a post-operative pancreatic fistula. So far, this test has only been carried out on the first and third day after the operation. It can take up to six hours before the results of these examinations are available. In addition, this only provides information on the patient's condition at a specific point in time.

Development of a millifluidic device

As continuous monitoring of alpha-amylase has not been possible to date, the adjustment of medical treatment in the event of complications can be delayed and thus worsen the prognosis for patients. This is why the team led by Dr Larysa Baraban at the HZDR Institute of Radiopharmaceutical Cancer Research, together with colleagues from the Department of Visceral, Thoracic and Vascular Surgery at the UKD, has developed a portable, droplet-based millifluid;The Millifluidik device, which is based on a droplet, can be used to measure the alpha-amylase activity of the drainage fluid for post-operative monitoring of patients in real time. Millifluidics means that fluids are passed through tubes around one millimetre in diameter. A tiny amount of drainage fluid is continuously collected from patient samples and encapsulated with a starter reagent in nanolitre-sized droplets. The use of this microfluidic vial format reduces the time between sampling and readout to one to two minutes.

In order to be able to determine the strength of the reaction, Baraban and her team work with a fluorescent dye. The fluorescence increases with increasing concentration of alpha-amylase. Put simply, the more intense the dye, the higher the concentration of alpha-amylase in the drainage secretion, which indicates the presence of a post-operative pancreatic fistula. In clinical practice, such a result could be followed by further examinations at an early stage in order to avoid serious complications for patients.

Validation of the new device

To validate their newly developed technology, the researchers compared the alpha-amylase values determined using the conventional method with those of the new device in 32 patients following pancreatic surgery. The values matched in 31 of the 32 patients. This confirms the reliability of the new Millifluidik device.

The advantages of the new device are obvious: "Our method reduces the duration of alpha-amylase determination from six hours to around two minutes and enables real-time monitoring of amylase activity at the bedside. In addition, our drop-based millifluidic device fits comfortably at the patient's bedside," Baraban summarises. „This allows complications to be recognised more quickly and appropriate treatment to be initiated.“ 

As the new development can be extended to analyse various body fluids and diseases as well as a wider range of biomarkers, the researchers assume that the new methodology could become the standard in post-operative patient monitoring in the future. HZDR, UKD and the Medical Faculty of TU Dresden are supporting this joint project with an internal fund.

Press release of the "HZDR" from 21 February 2024