Multispectral characterization of tissues encountered during laparoscopic colorectal surgery 91 Introduction Great public attention is paid to surgical safety, in particular the safety of endoscopic surgery1. In addition, efficiency is of constant concern in modern healthcare. Hence, dedicated clinical programs have been designed for inguinal hernia and gallbladder surgery to increase patient volume, improve safety and efficiency and thus save money. Colorectal surgery is the latest form of high‐volume‐surgery for which laparoscopic techniques have now widely been introduced. This is an advanced procedure requiring a high level of endoscopic skills. As an example, Kim (2009) gives a detailed description of the laparoscopic low anterior resection (or rectum resection) in an electronic reference2. Finding and identifying the right tissue structures and anatomical planes takes time and has its risks. Iatrogenic vascular injury, ureter lesion and nerve damage are some examples of complications that may occur. To identify the correct anatomical planes, different types of fatty tissue and blood vessels are used for orientation. If in addition to normal vision and common anatomical knowledge, essential anatomical planes and structures could be additionally enhanced or even specifically identified, this would beneficially influence the safety and efficiency of laparoscopic colorectal surgery. Multispectral imaging uses light at wavelengths beyond the visible range to enhance tissue structures. Tissue contrasts and light penetration depth vary with wavelength. Using these phenomena, hidden structures under a layer of fatty or connective tissue can, for instance, be visualized by utilizing spectral differences of the reflected light. For example, it is well known that vasculature perfused with highly oxygenated blood reflects near‐infrared light in a different way than vasculature perfused with deoxygenated blood3,4. With electronic processing, the difference can be visually enhanced. In cardiac surgery, these two characteristics have led to a clearer, in‐depth visualization of the coronary arteries, and clearer differentiation from adjacent veins5‐7. The goal is to help develop an endoscopic imaging device enabling laparoscopic surgeons to more clearly distinguish critical anatomical structures (e.g. ureter, arteries, veins, nerves) by selective contrast enhancement and in‐depth visualization of these structures (without administration of a chromophore or fluorophore or other contrast agent). As a first step to achieve this, diffusely reflected wide band light spectra were measured from different tissue types in freshly resected colonic specimens: healthy colonic tissue, arteries, veins, ureter, and mesenteric fat. A mathematical method was then applied to distinguish between these tissue types based upon analysis of the observed spectra.
proefschrift_Schols_SLV
To see the actual publication please follow the link above