Endoscopy (synonym: mirroring; endoscopy – from the ancient Greek endo: inside; skopein: to see) is a diagnostic procedure in medicine, with which the observation of various body cavities and hollow organs in the human body is possible. Endoscopy is a procedure that is used in various medical disciplines. With an endoscope, it is not only possible to reach and assess body regions that would not be visible without the use of a surgical procedure, but also to achieve an improved representation than with a conventional surgical procedure with the help of, among other things, magnification, subsequent image processing and staining methods. In today’s world, the term endoscopic examination does not represent the mere use of an endoscope, but rather a combination of various elements such as modern data and image processing, sensor technology and state-of-the-art control elements. Due to the ever advancing technology and the additional technical capabilities of endoscopes, a strong miniaturization of the individual components is required. Endoscopy was largely developed by the German physician Philipp Bozzini, who in 1806 used a light guide consisting of a candle and a prism system to inspect the various orifices of the body. In 1853, the endoscope was further developed through the use of an improved light system. It was not until 1879 that the modern endoscope was born, when Max Nitze introduced his cystoscope with a field of view extension.
The procedure
The principle of endoscopy is the visualization of the internal hollow organs of the human body through the use of a light guide, a light source, and an endoscope. The light sources used today are primarily adjustable xenon lamps, as these develop a particularly high luminosity and make it possible to perform a digital endoscopic examination. Furthermore, it is possible to replace the xenon lamps with LEDs and thus achieve lower heat generation and lower power consumption. Fiber optic light guides are often used for improved illumination of the cavities. Also required is the presence of a gas pump, which allows the controllable introduction of air to fill the cavities. Furthermore, an irrigator (liquid container for carrying out flushing) is also required. Since, despite adequate preparatory measures such as fasting before a colonoscopy, bile acid or small food residues may be found in the examination area, making it difficult to assess tissue structures, medical endoscopes are equipped with suction units. The following types of endoscopes are distinguished:
- Rigid endoscopy: When examining with a rigid endoscope, fiberoptic light guides are used for light conduction. Xenon lamps are used almost exclusively as the light source. Image information is relayed through a lens system localized in the shaft of the endoscope. The information is passed on to the eyepiece via the lens system. In rigid endoscopy, which can be used both as a diagnostic and therapeutic procedure, it should be noted that the endoscope must be inserted into the body under visual control. Because of this, assessment of the actual depth of penetration is difficult and requires some experience on the part of the attending physician. Classical examples of rigid endoscopy are cystoscopy and rectoscopy. As a special feature of cystoscopy (cystoscopy) is to list the ability to move catheters and other instruments.
- Flexible endoscopy (synonyms: flexoscope, flexiscope): with a flexible endoscope, not only the light conduction takes place via a flexible fiber optic cable, but also the image transmission. Video endoscopy, which has revolutionized the examination of the gastrointestinal tract, the bronchial system (pulmonary system) and the uterus, is also part of flexible endoscopy. In the video endoscopes in use today, a digital computer chip located on the lens of the endoscope serves both to transmit the image and to create the image. Via computer-aided processing, which functions differently depending on the manufacturer, the digital information is transferred to a screen and can be stored.
The implementation and preparation of an endoscopic examination varies, of course, very much with the respective examination areas. In principle, however, it should be noted that in the majority of endoscopic examinations, premedication with, for example, propofol. For both flexible and rigid endoscopy units, the primary use in diagnostics has shifted to increased use in therapeutic medicine. Therapeutic endoscopy, also referred to as interventional endoscopy, is a method of minimally invasive medicine. The following procedures using the flexible endoscope now frequently replace conventional or laparoscopic methods:
- Tumor and polyp ablation in the gastrointestinal tract (gastrointestinal tract) with possible mucosal resection (mucosal removal).
- Endoscopic papillotomy (splitting of the papilla duodeni major – small elevation with a sphincter muscle, the Musculus sphincter Oddi, at the common mouth of the common bile duct (Ductus choledochus) and pancreatic duct (Ductus pancreaticus) into the duodenum – including the sphincter apparatus).
- Endoscopic coagulation
- Percutaneous gastrostomy (PEG) – placement of a feeding tube. This is inserted through the abdominal wall into the stomach with the help of an endoscope.
- Fistula adhesion
- Cyst drainage
- Closure of perforations using stents, for example.
- Correction of intraoperative complications such as anastosmosis insufficiency, which can be corrected by fibrin sealant units.
- Palliative measures such as recanalization therapy, etc.
Among the more recent developments in endoscopic procedures is the capsule endoscopy. In this procedure, the patient swallows a mini camera, which is applied as a pill. It is transported through the entire gastrointestinal tract and takes pictures of the surrounding tissue at regular intervals. However, this procedure, which is used especially for small tumors and bleeding that are difficult to detect, cannot replace a conventional colonoscopy. In the future, increased miniaturization should make it possible to perform endoscopic examinations without premedication. Furthermore, endoscopic examinations for the assessment of defined brain areas should also be available. The most important endoscopic measures are presented below:
- Arthroscopy (joint endoscopy).
- Antroscopy (maxillary sinus endoscopy)
- Bronchoscopy (lung endoscopy)
- Endosonography (endoscopic ultrasound (EUS); ultrasound examination performed from the inside, i.e., the ultrasound probe is brought into direct contact with the internal surface (for example, the mucosa of the stomach/intestine) by means of an endoscope (optical instrument)).
- Gastroscopy (gastroscopy).
- Hysteroscopy (uterus endoscopy)
- Colonoscopy (colonoscopy)
- Laryngoscopy (laryngoscopy)
- Laparoscopy (laparoscopy)
- Esophagoscopy (esophagoscopy)
- Pharyngoscopy (pharyngoscopy)
- Urethrocystoscopy (urethral and bladder endoscopy).
- Etc.
Note
- During sedation in endoscopy, monitoring of pulse oximetry and blood pressure measurement should be obligatory!
