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 an arthroscopy. Surgery completed through a small incision and assisted with special instruments, such as the endoscope, is called keyhole surgery.
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.
In this article, we will investigate the various types of endoscopy procedure, why and how they are performed, and what the associated risks are.
Contents of this article:
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
- The first endoscope was designed in 1806
- Wireless, swallowable capsule endoscopes are a relatively new innovation
- The main reasons for endoscopy are investigation, confirmation, and treatment
- 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 source 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; for 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 through 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 treat an illness directly; 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.
An endoscopy is typically performed while the patient is conscious, although sometimes the patient will receive local anesthetic (commonly an anesthetic spray to the back of the throat); often, the patient is 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.
The procedure does not require an overnight stay in hospital and usually only takes around 1 hour to complete.
Risks of endoscopy
Although endoscopy is a relatively safe procedure, there are certain risks involved.
Risks of endoscopy include:
- Over-sedation (sedation is not always necessary)
- Feeling bloated for a short time after the procedure
- Mild cramping
- A numb throat for a few hours due to the use of local anesthetic
- Infection of the area of investigation: this most commonly occurs when additional procedures are carried out at the same time. The infections are normally minor and treatable with a course of antibiotics
- Perforation or tear of the lining of the stomach or esophagus: occurs in 1 in every 2,500-11,000
- Internal bleeding: usually minor and sometimes treatable by endoscopic cauterization
- Complications related to preexisting conditions
If any of the following symptoms occur following an endoscopy, medical help should be sought:
- Dark colored stool
- Shortness of breath
- Severe and persistent abdominal pain
- Chest pain
- Vomiting blood
Endoscope use in surgery
Endoscopes used in surgery help minimize bleeding and recovery times.
Endoscopy has advanced in recent years, enabling some forms of surgery to be conducted using a modified endoscope; this makes the surgery less invasive.
Procedures such as the removal of the gallbladder, sealing and tying the fallopian tubes and the removal of small tumors from the digestive system or lungs are now commonplace.
A laparoscope is a modified endoscope used for keyhole surgery (also referred to as laparoscopic surgery).
Laparoscopic surgery requires only a small incision and can be used for appendectomies (removal of the appendix), hysterectomies (removal of the uterus) and prostatectomies (removal of prostate tissue).
Using this technique, patients lose less blood during and after surgery and can recover much faster compared with standard surgical procedures.
What is a capsule endoscopy?
Capsule endoscopy was developed in the mid-1990s and utilizes a wireless camera. The camera is small enough to fit into a capsule (roughly the size of a vitamin tablet) and can, therefore, be swallowed.
As the capsule travels through the digestive tract, it takes thousands of pictures which are transmitted to a device attached to a wearable belt.
Capsule endoscopy is used to image the small intestine, a region that is difficult to image using standard endoscopy. It is also very useful for examining the small intestinal mucosa and diagnosing Crohn's disease. The capsule usually passes through the digestive system within 24-48 hours.
This is a relatively new technique and was given FDA approval for use in the U.S. in 2001. To date, more than 500,000 capsule endoscopy procedures have been carried out, and nearly 1,000 articles have been published covering its clinical use.