A small catheter with a nozzle at the end that applies highly concentrated chemotherapeutics in the form of a spray exactly where they are needed. Last year, David Hoskovec, the head of the 1st Surgical Clinic of the General Hospital in Prague, came up with such a vision. He asked the Czech manufacturer of medical and rescue aids, the company SKALA-Medica, which took over the development. Specialized measurements were then supplemented by experts in fluid mechanics from the Faculty of Mechanical Engineering, Brno University of Technology.
Measurements in the Spray Laboratory at FME BUT in Brno
The so-called microatomizer is intended for spraying highly concentrated cytostatics in the abdominal and thoracic cavities. The new technique will offer doctors an alternative to peritoneal lavage, which is currently the most effective treatment in the final stages of the disease. In peritoneal lavage, a solution containing a heated chemotherapeutic agent is applied to the patient's abdomen or chest cavity to effectively destroy tumours. However, this method is limited by the extent of the patient's disability.
"It is a new method of administering chemotherapy to the abdominal cavity or the thoracic cavity. The advantage is direct administration into the abdominal cavity and thus bypassing the barriers that reduce the penetration of chemotherapy in standard administration orally or intravenously," the primary Hoskovec explains. "In the case of peritoneal lavage, there are known cases in our territory where patients who have already been sent home for life expectancy survive at the age of 12, without recurrence. According to clinical forecasts, the procedure with the help of a new technique should affect hundreds to thousands of Czech patients a year, while the procedure is repeated by patients,” the developer Radim Skála from the SKALA-Medica company adds.
Experts from BUT helped with the development
The company needed to clarify what the spraying of cytostatics using nozzles looks like: how droplets of a substance flow, how fast they are, and how they behave when they hit the tissue. And based on that, evaluate how the spray will behave in a very complex environment. The developers from Soběslav, therefore, approached experts from the Faculty of Mechanical Engineering at the Brno University of Technology with a request for assistance.
"We were in the final stage of development, when Mr. Hoskovec and I were dealing with the dilemma of which spray design variant to choose in order for the product to be as effective as possible for patients. Therefore, we turned to the most professional in the Czech Republic and the cooperation with BUT proved to be key in the project. They performed measurements that we were not able to perform in Soběslav and Prague,“ Skála says.
"Our Spray Research Laboratory is uniquely equipped for similar measurements, as the only one in the Czech Republic," Jan Jedelský, the head of the laboratory, who and his team assessed various development versions of the new nozzle for the company. "Using our optical systems, we can measure every drop of solution, its size, speed and flow direction with a laser. Using another measuring system, we then see what the spray looks like during spraying and during the impact and what happens to it next. In this case, for example, we have found that the droplets are of such a size and velocity that they adhere to the surface and do not bounce off. The speed of the drops was also important for the manufacturer, which, according to the assumption, could improve the penetration of the substance into the diseased tissue and thus increase the therapeutic effect,“ Jedelský specifies.
Yesterday was too late
Experts in fluid mechanics started the measurement in no time. The company's goal was to put the tool into practice as soon as possible. "When asked when we need to know the results, I told Mr Jedelský that it was late yesterday. The purpose was to immediately start the certification of the microatomizer, so that even current patients can be checked in, i.e. people who have a few weeks, maybe even days of life left and cannot wait," Skála explains, who received the first measurement results from BUT in less than a week and quick cooperation.
The experiments were performed on simplified models, the toxic substance was represented by water, the abdominal cavity by a glass box. "We study the mechanics of fluids from a physical point of view, we do not solve the medical part, so this simplification was enough for us to begin with. In the future, however, it would be possible to further investigate and improve the nozzles, for example, to create a model of the abdominal cavity based on CT images in 3D printing,” Jedelský adds.
The introduction of the tool into clinical practice is now undergoing a certification process. "We expect that the first certified MCR-4 TOPOL atomizers will be available to Czech and Slovak patients from May to June this year. In terms of construction, design, management and clinical studies, the microatomizers are ready for use, we can deliver them to the clinic in a matter of hours. We have done our utmost to ensure that the device can be put into operation as soon as possible. I wish patients and their families not to give up and endure their struggle," Skála concludes.
To find out more about Spray Research Laboratory visit https://eu.fme.vutbr.cz/dept-of-taee-laboratories-spray-research-laboratory-2j