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Endoscopes – more than just insights

Endoscopes are developing into multifunction instruments, which not only localise surgical areas and concealed details inside the body, but which are also able to be put to invasive use. Endoscopes are now an integral part of modern and networked OP concepts.

The images offer an insight into a bizarre world of tunnels and whilst the camera takes new photos every two seconds, the cordless video capsule travels through the body’s interior, as if by magic. At times, the camera is only able to advance with difficulty, before suddenly moving faster. The exciting part is when it makes its way through the small and large intestines. The alimentary tract is up to six metres long and can only be examined in detail with great effort.

The capsule endoscopy is able to do just this. The images are of a high definition and the physician edits the images to form a video film which shows the journey which the camera-equipped plastic capsule makes through the body, together with all of the important stops.

Whether cordless or with a fixed connection with the outside world – innovative endoscopy techniques have a decisive advantage. They provide live images of the living organism.

Flexible endoscopes are even able to adapt themselves to meandering paths or are able to look around corners. Not only that, they are also equipped with an increasing number of tools which they can also take with them through small access channels. Manufacturers such as Richard Wolf have not only developed mobile forceps, but also bending cutters which can be used to resect bone material at the planned operation site.

The use of fully endoscopic methods for spinal surgery is already here. The new Tipcontrol instruments series from Richard Wolf used the working channel of the endoscope in order to sclerose diseases tissue or to obtain improved access by means of a cutter. The operating surgeon uses a joystick. The endoscopic access through the working channel of the endoscope brings light into the surgical area and also enables neural hooks to be used. This sparing minimal invasive surgery has clear benefits when compared with traditional invasive methods: smaller wounds, fewer tissue injuries and pains, a reduced blood loss and shorter recovery times.

The endoscopy specialist Karl Storz is not only one of the heavyweights in the endoscopy environment with 8.000 products for 22 medical disciplines, the company is also a pioneer when it comes to minimal-invasive surgery. The family-owned company from Tuttlingen in Germany has in recent years, extended its portfolio in the direction of a surgical cockpit and OP management. The endoscopic examination is increasingly expanding to form an imaging and therapeutic process with a digital camera platform, rinsing and tool set and a three-dimensional image recording system.

Karl Storz underlines the commencement of the company’s involvement in digital systems technology. The Image One camera system provides a continuous digital information transfer in addition to data storage on conventional storage media, so that it is protected from losses. The device processes endoscopic freeze frames in high-definition (HD) mode and video recordings utilise the MPEG-4 format. The camera not only supports standard video signals, but also other digital video formats such as DV, DVI, SDI and Ethernet. The Image 1 platform comprises a large selection of camera heads, which enable a customised configuration to be carried out which meets the needs of the various disciplines.

A Storz development is searching a way to enable an endoscopic viewing of molecular cell and tissue structures, in which the endoscopy makes use of the fluorescence method which is known from the field of laboratory analytics. With the assistance of a new light source, the endoscope stimulates a previously injected marker with a red light and records the fluorescent indicator substance. This method is useful for the controlling of the blood supply to organs. The devices and instruments which are required for this fluorescent method, such as the light source, camera and optics, have the great advantage that they can both be used for the OP in white light and for the subsequent fluorescence control.

Nowadays, endoscopes with a flexible catheter probe with numerous lumens and a minimum of one optic fibre are no longer a thing of the past. The tools repertoire includes biopsy forceps, electric loops, injection needles or ultrasound probes. The other side of the coin concerns itself with questions of safety and the risk of injuries being caused by unsuitable instruments. The focus of the instrument controls is therefore to be both on the wear of the supporting members of the flexible endoscope, together with the disinfection or sterile cleaning for continued use.

The flexibility of flexible endoscopes is decisively dependent on the condition of the hinge axis of each of the instrument rings. Should the tolerances between the moving links change during use, the instrument will gradually loose the original precision. Specialists repeatedly report shaping of the bending part being caused by bending stress. This can even have an effect on the position of the working channel and within the instrument and cause damage to its surfaces.

Endoscope manufacturers have a large amount of knowledge concerning the safety and preparation of their instruments. Flexible endoscopes comprise various materials such as plastics, metal and glass. The manufacturers normally have a precise knowledge of which disinfectants and cleaning agents can cause undesirable interactions. There are also design tricks which shield the optic channel from direct contact with the tissue, for example. When using such an endoscope, it is not necessary to sterilise the optic fibre after each application as this is hermetically separated from the inside of the body during the treatment, by means of a transparent cover.

Both service providers and the manufacturers provide assistance with the preparation of the instruments. Richard Wolf launched a sterilisation container with maintenance-free sealing system onto the market in series at the end of last year for example. The Sterisafe no longer requires the silicon seals which are normally standard and which are prone to wear, so that they have to be replaced at regular intervals. Instead of this, the top and bottom parts of the housing are fitted with a seal geometry which prevents germs from entering the container. Storz provides an overview of the most suitable cleaning forms. The steam sterilisation of flexible endoscopes is not possible due to their thermal sensitivity, but they can be subjected to a chemical-thermal preparation in autoclaves.

Andreas Beuthner

German Summary

Endoskope entwickeln sich zu Multifunktionsinstrumenten, die nicht nur Operationsgebiete eingrenzen und verborgene Details im Körperinneren zugänglich machen, sondern auch eingreifen können. So sind Endoskope mittlerweile fester Bestandteil moderner und vernetzter OP-Konzepte. Der deutschsprachige Beitrag ist nachzulesen auf www.meditec.mi-verlag.de/medi0311endo