A safe and comfortable test that saves lives
With an increasing number of patients suffering from gastrointestinal cancers, especially that of the esophagus, stomach and colon, the early detection of cancer has assumed utmost importance. One of the most reliable methods of screening for, or detecting such cancers is ‘endoscopy’. Dr Tan Chi Chiu, who is a consultant gastroenterologist and physician with sub-speciality interest in therapeutic endoscopy, at the Gastroenterology and Medicine International located within the Gleneagles Medical Centre in Singapore, talks to Gaurav Sharma about the growing importance of endoscopy and at the same time dispels various misconceptions surrounding it.
Q : I understand that you have over 20 years of experience as an endoscopist. Can you define the procedure for the benefit of our readers?
Tan: The endoscope is a technologically advanced device comprising of a thin, flexible tube fitted with a camera head and light guides, which is gently inserted into the human body by an endoscopist and moved through the gastrointestinal tract to provide a clear picture of the inside of the esophagus, stomach, duodenum and colon. Some special endoscopes also provide for examining the bile and pancreatic ducts.
A skilled and experienced endoscopist understands the cognitive aspects of endoscopy and knows what to look for and what to biopsy. While the ‘gastroscope’ examines the oesophagus, stomach and duodenum, the ‘colonoscope’ examines the large intestine or colon. Once the tube is inside the gastrointestinal tract, true-to-colour images are relayed electronically and displayed in real time on a monitor. Photographs or DVD recordings are also made available to the patients for future reference. If biopsy specimens are taken, the result of the tissue analysis will be known in a few days.
Q : has endoscopy assumed so much importance in recent years?
Tan: As is well known, colorectal cancer is the most common cancer in the world. It is the most common cancer in men and the second most common in women after breast cancer. It has been shown by studies that if screening colonoscopy is done at the age of 50 for people at average risk, lives can be saved due to early detection of either cancer or polyps that can grow into cancer.
If there is a family history of colon cancer or polyps, the risk may be higher and may justify screening at an earlier age. At the same time, stomach and oesophageal cancers continue to be very important, although recommendations for screening are not hard and fast. But as with all cancers, they are potentially treatable if detected early. And one of the most reliable methods of doing so is by endoscopy. Although there are many other ways of screening for digestive tract cancers, studies have consistently shown that endoscopy is superior and remains the ‘gold standard’.
Q: Can you please elaborate a bit on the various uses of an endoscope? What are its benefits?
Tan: Endoscopy can not only diagnose digestive tract diseases, treatment can also be provided
through endoscopes, sometimes called ‘therapeutic endoscopy’. This is one of the reasons for the growing popularity of endoscopy. We can pass special instruments through an endoscope to remove smaller polyps and tumors without surgery, stop bleeding lesions by injection or cautery, stretch narrowed passages through dilatation, place stents through blocked tubes and remove gallstones from the bile ducts.
An ultrasound device fitted to the endoscope is also used to examine the walls of the digestive tract in detail, to see how deeply a cancer has invaded. This technique of ‘endoscopic ultrasound’ can also be used to study organs outside the digestive tract. For example, pancreatic cysts can be examined and even biopsied through the stomach wall. Even a laser fibre can be passed down the endoscope to burn away cancers where appropriate. The latest developments are designed to examine the small bowel, which was previously inaccessible. We have ‘capsule endoscopy’ or single or double-balloon endoscopy to achieve this.
Q: Now, let’s talk about the various misconceptions surrounding endoscopy. Some believe that the endoscopic procedure is very painful and uncomfortable. Can you quell this misconception?
Tan: Yes, because endoscopy is such an important tool, it’s very important that misconceptions surrounding endoscopy are cleared once and for all. With technological advancements, modern endoscopes are very thin, flexible and designed with patient comfort in mind.
Moreover, for patients undergoing gastroscopy and colonoscopy, we use local anaesthesia in the form of a throat spray along with gentle intravenous sedation carefully titrated to each individual patient. Contrary to what some people believe, the patient is not gagging with the scope in his throat. Patients are generally very comfortable throughout the procedure and usually wake up with no memory of having gone through them. In fact, nowadays most patients undergo endoscopy as day-cases and are in the endoscopy suite for a couple of hours at most.
For colonoscopy, bowel preparation to clean the colon can be a little inconvenient because the patient will have to move the bowels several times before coming for the endoscopy, but again this is not painful or uncomfortable. Some patients don’t like the taste of the bowel preparation laxatives, but nowadays the volume is as little as two cups taken at an hour’s interval and the solution can be diluted with cordial or even 7UP to taste acceptable.
Another misconception is that gastroscopy will leave the patient with a sore throat for a long time. This is not the case and at the end of gastroscopy, most patients have no knowledge that they even underwent the procedure. Some think that colonoscopy will cause a permanent change in the patient’s bowel habits. This is also not the case. There may be a bloated sensation for a short time due to air being pumped into the intestine in order to see the walls clearly, but the air is quickly passed out and there is no lasting discomfort.
Q: How safe is endoscopy? Would there be any complications arising from the procedure?
Tan: Experience is everything and an experienced endoscopist will have a very, very low complication rate. So low that endoscopy may be regarded as a routine procedure. Diagnostic examinations are generally very safe. But as is the case with every medical procedure, in spite of all precautions taken, certain complications may arise in endoscopy especially when we have to perform various therapeutic procedures like removing large polyps, dilating a narrowed segment, or placing a by-pass tube. Complications may include bleeding or perforation of the digestive tract. For such cases, the most important thing for the endoscopist is to identify the complication and take corrective action at once. But such cases are very uncommon.
Dr Tan Chi Chiu
Gastroenterologist & Physician
With more than 27 years as a doctor and 17 years as an accredited Gastroenterologist,Dr Tan is a specialist in diagnostic and therapeutic endoscopy. He was trained in Singapore General Hospital, National University Hospital Singapore and in the United Kingdom. He is also the elected member as well as the chairman of the Medical Ethics Committee of the Singapore Medical Council. Website: www.gastromed.com.sg