Initial Clinical Experience with OPS Imaging for Observation of the Human Microcirculation

The microcirculation can be regarded as a vital and vulnerable organ requiring clinical monitoring in the peri-operative phase. This is especially evident in conditions where the function of the microcirculation is pushed to its limit such as occurs during surgery and on the intensive care unit (ICU). The microcirculation is also an important target organ in shock and sepsis. But, more localized diseases such as cancer or tissue damage can also cause the microcirculation to become compromised. Furthermore, many pathological disorders have their first effects and even their origin at the microcirculatory level. These effects on the microcirculation are present long before any macroscopic deterioration of the organ or tissue function is evident. The expectation of resuscitation strategies is that they restore microcirculatory function. Thus, monitoring the function of the microcirculatory areas at risk may be of crucial importance. However, no suitable techniques are available to routinely monitor the microcirculation clinically [1]. Direct observation of the human microcirculation has, until now, been limited to observations of capillaries in the nailfold by use of intravital microscopes (capillary microscopy) [2]. Such setups are too large to be applied as a bedside monitoring tool, let alone during surgery. Use of capillary microscopy is further limited by the uncertainty as to what extent capillaries in the nailfold represent the microcirculation in other, more vital, organ beds. Furthermore, because intravital capillary microscopy is directed at the capillaries of the nailfold, little information is gained about the properties of the arterioles, venules and microvascular architecture.