gms | German Medical Science

In general surgery, and especially in tumour surgery, critical situations may arise which necessitate the separating out of complex tissue formations with a high degree of accuracy, as for example when vascular walls or neural structures are infiltrated by tumour strands. In many cases an important, physiologically functional structure could be preserved if a surgical instrument existed that allowed the necessary level of precision. A femtosecond (fs) laser is suitable for this purpose as, with its small focus and minimal collateral damage, it meets the necessary requirements. This system is, however, owing to its dimensions, not controllable by the surgeon. The idea was conceived, therefore, of designing an automatic assistance system which combines optical coherence tomography (OCT) (acting as a sensor) with the fs laser (serving as an actuation driver), which – partly autonomously – performs crucial stages in the surgical procedure under the surgeon’s control. A prerequisite for a system of this nature is, however, that it be tailored to physiological movements within the surgical site. These movements must, in order to establish a pool of measurement data, be recorded with the precision required by the dimensions involved. To this end, one-dimensional (1-D) OCT measurements were carried out on test persons. There is, however, an extensive literature dealing with in vitro mapping of various biological tissues. In vivo measurements and reports on these investigations are, however, still rare. Especially given the complex anatomy of the head and neck region, a non-damaging, contact-free and high-resolution system is both useful and desirable. This is performed by optical coherence tomography, which also provides additional intraoperative information.