Video-rate multispectral imaging in laparoscopic surgery: First-in-human application

Minimal invasive procedures are often preferred over open surgeries because they result in smaller scars, fewer complications and a quicker recovery of the patients. However, they come at the cost of reduced mobility and perception limitations of the surgeon. In many laparoscopic surgeries, for example, it is necessary to stop the blood flow to a specific organ or tissue region by clamping the arteries responsible for blood supply. This procedure, commonly referred to as ischemia induction, prevents excessive bleeding of patients [Tho+07] and is performed in various procedures, including partial nephrectomy, organ transplantation and anastomosis. After clamping the main arteries, it is highly challenging to assess the perfusion state of the tissue solely based on the available RGB video stream. This holds especially true when selective clamping of a segmental artery is performed, in which ischemia is induced only in the cancerous part of the kidney during partial nephrectomy [McC+14; Bor+13] Traditional approaches to improving surgical vision involve fusing preoperatively acquired images with the situs [MH+18]. Such "offline" methods, however, cannot react on dynamics. The most common approach to ensure correct clamping is based on indocyanine green (ICG) fluorescence: after ICG is injected into the blood stream, it binds to the plasma. The bound ICG travels through the blood stream and accumulates in the internal organs, especially in the kidney and liver, within a minute [Tob+12; Gan+16].