Endoscopy is a pivotal and revolutionary technological tool employed today by our gastroenterologists. The evolution of endoscopic technologies was pushed by the desire to investigate the human body without the risks of incisions and surgery
By DR. MARK ANTHONY A. DE LUSONG
Physicians, scientists, engineers, and inventors all came together to accelerate the developments we now see in endoscopy. The evolution of endoscopy has been rapid and dramatic, from the first ever documentation of redirecting sunlight into the human body in the 16th century to electric lighting illuminating tubes to see our intestines.
One of the major endoscopic revolutions was the invention of flexible endoscopes allowing access to previously dark, tight and angular intestinal lumen. These were flexible tubes with cameras that made taking videos and photos of our gastrointestinal tract possible. This was then rapidly replaced by digital video endoscopy that allowed viewing from large digital screen during endoscopic intervention.
Then came swallowable camera capsules making endoscopic examinations of the previously inaccessible smallintestine possible. Innovative imaging technologies further expanded the diagnostic arena with technologies like narrow band imagingand fluorescence endoscopy. All of these technological evolutions and revolutions made medical endoscopy an invaluable tool in many diagnostic processes.
Imaging the GIT
In the 16th century, an Italian physician, Giulio Aranzi was the first medical practitioner documented to direct sunlight into a bodycavity by using a flask of water to reflect light into a patient’s nose. This led to other pioneers attempting to image the gastrointestinal tract.
The first technologically successful attempt was made by Philipp Bozzini who invented the ’Lichtleiter’ or light conductor which was a metal casing that held a candle for illumination. Holes were placed on one side, to which he attached metal tubes to guide the light into the human body. On the other side of the casing were openings to look into. But due to the apparatus’ heat and smoke created by the candle, it did not gain wide acceptance among medical practitioners.
This revolutionary machine was then improved by Antonin Jean Desormeaux who replaced the candle with a mixture of alcohol and turpentine increasing the intensity of the light. He also was first to successfully do endoscopic procedures in living patients and is credited to be the ’father of endoscopy’.
The first endoscopic revolution was made by Johann von Mikulicz-Radecki in the 18th century. He used Nitze’s concept of putting a light at the end of a rigid examining tube and added an air canal to his endoscope enabling insufflations of collapsed cavities under observation. This was later dramatically updated by the invention of the first flexible esophagoscope by Kelling and Albright in 1898. The lower third of this endoscope could be flexed allowing a wider field of view. Further improvements were made by Schindler with an improved version of a semi flexiblegastroscope in 1936. This system was an improvement over prior endoscopic technologies but still had blind spots which could not be directly visualized.
Since earlier endoscopes require the observer one eye to look along the optical axis of the endoscope just like a telescope, only a single person could view intestinal organs at a time. This drove inventors to improve the technology further.
Later on, the first reported video endoscopy was conducted by Soulas in France in 1956. Video equipment was still very large and heavy at this point in history and rigid endoscopes were fixed to a regular television camera. Video images were also transmitted to a television monitor in black and white. Further improvements made these cumbersome endoscopy equipment more portable and mobile cementing them as the standard method for gastrointestinal examinations and interventions.
In 1985, the invention of digital imaging with charge-coupled device image sensors and miniaturization of cameras was a technological breakthrough. Further technological breakthroughs increased the flexibility of the endoscopes and further increased the image quality they produced. Today, digital video and image enhancement technologies are built-in in most endoscopic video units.
A new technological update for endoscopes is spectral endoscopy which allows the detection or easy diagnosis of specific gastrointestinal diseases. This uses various illumination techniques in standard endoscopy and has enhanced the visibility of features that cannot be distinguished under conventional white light. One of these spectral endoscopic technologies is Narrow-Band imaging (NBI).
The blue light it emits at 415 nm enhances the superficial capillary network, while the green light at 540 nm displays subepithelial vessels. The combination of the two light bands highlights the blood vessel pattern, which can be essential for certain diagnoses and detection of malignancies.
Other notable developments in the field of endoscopy are the capsule endoscopy. Invented by Gavriel Iddan initially for military applications, this is a mini-camera in capsule form given to a patient and swallowed. The pill contained a digital camera and an 8-hour battery housed by medical grade plastic coating. The capsule takes two images per second or approximately 60, 000 images. This pillcam is primarily used to visualize diseases in the small intestine in which if a lesion is found, another endoscopic marvel is used, the device assisted enteroscope. The device assisted enteroscope uses balloons or anchoring devices to plicate or shorten the 6 meter long small intestine while simultaneously evaluating its mucosa. This enteroscope now is able to save a multitude of patients from a major surgery like exploratory laparotomy from small intestinal diseases treatable with an endoscope.
Finally, an endoscope capable of both video endoscopy and ultrasonography is now currently staging a revolution. Previous surgical treatments are now “minimalized” using this echoendoscope. Fluid collections and tumors historically removed by opening up a patient can now be treated endoscopically inside the patient without incisions.
Endoscopy is now a standard tool in medical examinations. The initial pioneering years were spent directing light into the body for examination. Rigid endoscopy heralded the coming of flexible endoscopy to catch a glimpse of dark and angulated intestinal lumen like the colon. Video endoscopy then revolutionized endoscopic diagnosis and treatment with multiple viewers and physicians able to see, discuss and treat a patient. Additional technologies that enhanced these systems include spectral imaging that improved diagnostic methods for detecting malignant gastrointestinal disease. Capsule endoscopes were developed to conquer the once unreachable small intestines. All these advancements make gastrointestinal endoscopy a standard and important tool in the diagnosis and management of gastrointestinal disease.
“Video endoscopy then revolutionized endoscopic diagnosis and treatment with multiple viewers and physicians able to see, discuss and treat a patient”
March 2018 Health and Lifestyle