Endoscopy is the insertion of a long, thin tube directly into the body to observe an internal organ or tissue in detail. It can also be used to carry out other tasks including imaging and minor surgery.
Endoscopes are minimally invasive and can be inserted into the natural openings of the body such as the mouth or anus.
Alternatively, they can be inserted into small incisions, for instance, in the knee; this is referred to as keyhole surgery.1
Because modern endoscopy has relatively few risks, delivers detailed images and is quick to carry out, it has proven incredibly useful in many areas of medicine.
In 1806, Philipp Bozzini, a German doctor, invented the first endoscope. He designed it to inspect the ear, urethra, rectum, female bladder, cervix, mouth, nasal cavity and wounds.
In the following 200 years, endoscopy has been highly utilized as a relatively safe way to observe the inner workings of the human body in health and disease. Today, tens of millions of endoscopies are carried out each year.2
In this article, we will investigate the various types of endoscopy procedure, why and how they are performed and what the associated risks are.
Fast facts on endoscopy
Here are some key points about endoscopy. More detail and supporting information is in the main article.
- Endoscopies are quick and relatively safe procedures
- Without the need for invasive surgery, an endoscopy can fulfill a number of roles
- The first endoscope was designed in 1806
- Endoscopes can be inserted into natural cavities in the body or small incisions
- Imaging the pancreas is made easier using an endoscope
- Wireless, swallowable capsule endoscopes are a relatively new innovation
- The main reasons for endoscopy are investigation, confirmation and treatment
- Risks associated with endoscopy are minimal but include over-sedation, bloating and internal bleeding
- Endoscopy can be used to remove tumors or polyps from the digestive tract.
Endoscopy can be useful in a wide array of medical situations.
A modern endoscope consists of the following components:
- Tube: either rigid or flexible
- Light: the light is normally outside of the body and directs light internally via an optical fiber system
- Lens system: designed to transmit the image from the internal end of the endoscope to the viewer. In rigid endoscopes, this is achieved by relay lenses; in flexible scopes, optic fibers are used
- Eyepiece: in more modern endoscopes this might be replaced by a display screen
- Additional channel: this allows for medical instruments or manipulators to be passed along the endoscope into the body.
Areas investigated by endoscopy
Endoscopy is useful for investigating a wide range of anatomical structures within the human body. These areas include:
- Gastrointestinal tract: esophagus, stomach and duodenum (esophagogastroduodenoscopy), small intestine (enteroscopy), large intestine/colon (colonoscopy, sigmoidoscopy), bile duct, rectum (rectoscopy) and anus (anoscopy)
- Respiratory tract: nose (rhinoscopy), lower respiratory tract (bronchoscopy)
- Ear (otoscope)
- Urinary tract (cystoscopy)
- Female reproductive tract (gynoscopy): cervix (colposcopy), uterus (hysteroscopy), fallopian tubes (falloposcopy)
- Through a small incision: abdominal or pelvic cavity (laparoscopy), interior of a joint (arthroscopy), organs of the chest (thoracoscopy and mediastinoscopy).
Reasons for endoscopy
The reasons for performing an endoscopy typically fall into one of three categories:
- Investigation: if a patient is experiencing vomiting, abdominal pain, breathing disorders, stomach ulcers, difficulty swallowing or gastrointestinal bleeding, an endoscope can be utilized in the search for a cause
- Confirmation: endoscopy can be used to complete biopsies (removal of a small section of tissue) to confirm a diagnosis of cancer or other diseases
- Treatment: an endoscope can be used to directly treat an illness; for instance, endoscopy can be used to cauterize a bleeding vessel or remove a polyp.
Sometimes endoscopy will be combined with another procedure such as an ultrasound scan. Endoscopy can be used to place the ultrasound probe close to organs that can be challenging to image, such as the pancreas.
Modern endoscopes are sometimes fitted with sensitive lights that use "narrow band imaging." This type of imaging uses specific blue and green wavelengths and allows the doctor to spot precancerous conditions more easily.3
An endoscopy is typically performed while the patient is conscious, although sometimes the patient will receive local anesthetic (often an anesthetic spray to the back of the throat);4 alternatively, the patient can be sedated.
For endoscopy procedures involving entry through the mouth, a mouth guard will be used to protect the teeth and lips as the tube is inserted.5
The procedure does not require an overnight stay in hospital and usually only takes around 1 hour to complete.
On the next page, we look at the risks of endoscopy, its use in surgery and capsule endoscopy.