St Petersburg University researchers are the first in the world to find a way to assess organ viability during minimally-invasive surgeries

Researchers from St Petersburg University together with doctors from the Sokolov Northwestern District Scientific and Clinical Centre have proved the efficacy of iPPG technique — imaging photoplethysmography — in laparoscopic, i.e. minimally invasive surgical interventions.

Remote imaging photoplethysmography (iPPG) is a non-contact technique for assessing tissue blood perfusion, using images in green backlight from a special camera synchronised with the electrocardiogram. Special software assesses the blood supply to organs. Importantly, the technique does not require intravenous administration of fluorescent indicator or any other special preparation of the patient.

The study was conducted by: Professor Viktor Kashchenko, Head of the Department of Faculty Surgery at St Petersburg University, Deputy Chief Physician for Surgery at OOO "My Medical Centre — High Technologies", and Chief Surgeon at the Sokolov Northwestern District Scientific and Clinical Centre; Aleksandr Lodygin, Associate Professor in the Department of Faculty Surgery at St Petersburg University; Valerii Zaitsev and Aleksei Kamshilin, researchers at the Institute of Automation and Control Processes of the Far Eastern Branch of the Russian Academy of Sciences; and Konstantin Krasnoselskii, anaesthesiologist at the Sokolov Northwestern District Scientific and Clinical Centre.

A few years ago, the St Petersburg University researchers proved the efficacy of the technique during surgical operations on the abdominal organs. Then, they reported their findings in the peer-reviewed journal Scientific Reports, published by Nature Portfolio, a division of the international scientific publishing company Springer Nature.

‘Today, doctors — if possible — prefer to perform laparoscopic surgeries that do not require large incisions,’ explained Viktor Kashchenko. ‘Such surgical operations are minimally invasive procedures, allowing for quicker patients’ recovery after the surgery.’ During such surgeries, however, it was difficult for surgeons to assess and control the blood supply to the internal organs in real time until the iPPG technique was introduced. The researchers from St Petersburg University and St Petersburg surgeons proved in an operation theatre that the technique is effective and safe for laparoscopic surgeries as well. The method was tested during laparoscopically-assisted surgeries in nine cancer patients (with stomach and colorectal cancers).

The research paper is published in the reputable medical journal Surgical Endoscopy. The research was supported by the Russian Science Foundation (project № 21-15-00265).

‘In essence, the technique remained the same, except that we used a standard laparoscope connected to a standard digital monochrome camera. Synchronous recording of video frames and electrocardiogram with subsequent correlation data processing enabled us to minimise the errors that inevitably occur due to the patient’s respiration and heartbeat,’ said Dr Kashchenko. Using the iPPG technique, the surgeons were able to continuously assess tissue perfusion of the affected organs in real clinical settings. 

‘The application of imaging photoplethysmography proved to be safe and feasible in all our patients. We have demonstrated the efficacy of the iPPG technique for visualisation and continuous quantitative assessment of tissue perfusion. The introduction of the technique into clinical practice will help to increase the number of minimally invasive surgeries; thus, reducing the number of possible post-operative complications and lethality,’ summarised Viktor Kashchenko.