Where Next for the Endoscope?

Ricardo A. Natalin; Jaime Landman

In This Article

Future Directions

The future of endoscopy is difficult to predict. However, we are likely to see improvements in this field that currently seem almost unimaginable. The creative application of novel technologies from other disciplines has always enabled endoscopy (and indeed all aspects of minimally invasive surgery) to move forward. Imaging devices will certainly continue to decrease in size, such that 'microendoscopy' will be feasible in the near future. Endoscopy of any luminal structure, including the vas deferens, will certainly follow.

Nanotechnology, including small robots built from novel materials, has already been demonstrated to be feasible. Self-assembling robots constructed from nucleotides have already been created. As has already been envisaged in science fiction, a time when small 'robots' will patrol biologic structures to constantly survey and help protect normal anatomy and physiology is not difficult to imagine.

The incorporation of advanced physics and molecular biology techniques will almost certainly complement endoscopy, and are likely to eventually eliminate the need for endoscopy altogether. The first efforts to assimilate molecular biologic techniques into endoscopy have been made. Raman endoscopy consists of a powerful light-scattering technique used to identify the internal structure of molecules and crystals. Light of a known frequency and polarization interacts with and is scattered by a sample. The scattered light is then analyzed for its frequency and polarization, which can provide information on the characteristics of the sample.[36]

Raman spectroscopy might greatly improve real-time histologic tissue diagnosis by measuring the molecular components of tissue in a qualitative and quantitative way. Light scattered by each tissue type has a characteristic spectrum, which can be used to generate a pseudocolor map; thus, by analyzing the tissue's spectrum we will be able to tell if its composition is of a normal or a pathologic nature.[37] The time needed to obtain such spectra is around 10–20s, which allows fast decision making that might enable real-time decisions as to whether to perform conservative or radical surgery, to define limits of resection or to differentiate benign from neoplastic tissue.

Another application of physics within endoscopy is optical coherence tomography (OCT). This imaging modality is capable of producing high-resolution, cross-sectional, subsurface tomographic imaging of the microstructure in biologic systems by measuring backscattered or backreflected infrared light. Its underlying physical principle is similar to that of B-mode ultrasonography, but instead of sound OCT applies light.

OCT devices use a low-power infrared light with a wavelength of 750–1,300 nm and images are generated from measuring the echo time delay and the intensity of back-scattered light. The depth of penetration of OCT imaging is approximately 1–3 mm, depending upon tissue structure, depth of focus, and pressure applied to the tissue surface. All the tissue layers of the bladder (urothelium, lamina propria, and muscularis propria) can be individually visualized by use of this technology according to their different light-reflecting properties.[38]

Patients with other pathologies might benefit from the use of OCT to improve treatment and surgical decision making. For example, in the future, OCT may help to evaluate neurovascular bundle involvement in patients with prostate cancer and thus inform resection decisions. Similarly, OCT might be applied to kidney, ureter and collection system tumors to help optimize resection.