Endoscopic Ultrasound: Uses, Types, Procedure, and Aftercare

An ultrasound for endoscopy (EUS) is a non-invasive procedure that uses ultrasound devices to analyse your digestive tract.

Gastroenterologists do this test to check for any health issues, such as cancers and abnormal growth.

EUS gives clear pictures and sometimes assists needle biopsies in places where tissues or fluids are examined to search for abnormal cells. This procedure helps in generating sharp images of your organs.

What is endoscopic ultrasound (EUS)?

An endoscopic ultrasound examination is a specialised diagnostic procedure that utilises an ECG and ultrasound to image your internal body parts using a thin, flexible tube known as an endoscope with an ultrasound probe integrated at its end.

During the procedure, the doctor gently puts the endoscope through your mouth or rectum, depending on the part of the body that is under examination.

During the process, the ultrasound probe sends sound waves that have high frequencies to measure units and are reflected back by the neighbouring tissues and organs. This forms vivid images of your

• Digestive tract

• Pancreas

• Liver

• Lymph nodes

• Other surrounding structures

EUS takes better precision imaging than the normal ultrasound. Instead of obtaining ultrasound images from outside the body, it places the probe next to the organs under examination. This close proximity provides clearer and more detailed images, allowing your doctors to accurately assess and diagnose conditions affecting adjacent organs.

EUS plays a crucial role in diagnosing and staging diseases, particularly those involving the gastrointestinal tract, pancreas, lungs, and lymphatic system.

Types of EUS Tests

Based on the area of the digestive tract they examine, endoscopic ultrasound procedures fall into two main categories:

Upper EUS Procedure:

This type of EUS focuses on the upper part of the digestive tract, including:

• The lining of the oesophagus, stomach, and small intestine.

• Lymph nodes, blood vessels, cysts, and tumours.

• Nearby organs such as the pancreas, gallbladder, and bile ducts.

Lower EUS Procedure:

This procedure examines the lower part of the digestive tract, which includes:

• The anal sphincter (muscles surrounding the anus).

• Blood vessels, lymph nodes, cysts, and tumours.

• The lining of the large intestine, specifically the rectum and colon.

What is endoscopic ultrasound used for?

Some of the key applications of EUS are:

1. Cancer diagnosis and staging

• EUS helps detect and stage cancers of the oesophagus, stomach, pancreas, rectum, and lungs.

• It determines the depth of tumour invasion and checks if cancer has spread to lymph nodes or nearby structures.

2. Evaluating pancreatic conditions

• EUS is used to diagnose pancreatic cysts, tumours, and chronic pancreatitis.

• It guides fine-needle aspiration for collecting tissue samples for biopsy.

3. Bile duct and gallbladder issues

• EUS detects gallstones or bile duct blockages that might not be visible on other imaging tests.

4. Gastrointestinal disorders

• It evaluates submucosal lesions (growths beneath the lining of the digestive tract).

• It is useful for checking conditions like Barrett’s oesophagus and gastrointestinal bleeding. It gives detailed images of the digestive system, which helps with diagnosis and treatment planning.

5. Lung and chest evaluation

• EUS can assess lymph nodes in the chest and surrounding areas through endobronchial ultrasound. This type of ultrasound is particularly useful for identifying lung cancer and evaluating other thoracic conditions.

To take charge of your health, book an appointment with Thomson Medical to meet our medical specialists and discuss a personalised treatment plan.

How does endoscopic ultrasound work?

EUS combines two advanced technologies to provide comprehensive views of your internal organs:

• Endoscopy: 

  • An endoscope is a flexible tube with a camera. 

  • It visually examines the internal lining of your digestive tract, offering detailed images of the surface tissues.

• Ultrasound: 

  • The ultrasound probe, attached to the endoscope, emits high-frequency sound waves that penetrate deeper tissues and organs. 

  • These sound waves bounce back, creating detailed images of structures located beneath the surface, such as the pancreas, lymph nodes, and blood vessels.

These technologies work together to give detailed views of your internal organs. Such information enables your healthcare providers to make precise diagnoses, guide biopsies, and plan appropriate treatments.

Preparing for endoscopic ultrasound

Before your EUS test, your healthcare provider will advise you on what to do and what to avoid, ensuring everything goes smoothly. Generally, you might need to do the following things:

1. Pre-procedure instructions:

• Fasting:

  • Do not eat or drink for 6–8 hours before the procedure if the endoscope is inserted through the mouth. 

  • For rectal EUS, fasting instructions may vary.

• Medications:

  • Discuss all medications with your doctor, particularly blood thinners, insulin, or heart medications.

  • You may need to temporarily stop certain medications.

• Allergies:

  • Inform your healthcare provider about any allergies, particularly to anaesthesia or sedatives.

• Transportation: 

  • Since the procedure typically involves sedation, arrange for someone to drive you home.

2. Bowel preparation (for rectal EUS):

• You may be required to take laxatives or use enemas the day before the procedure to clear your bowel, ensuring clearer images during the rectal EUS.

What happens during endoscopic ultrasound?

1. Pre-procedure:

   • You will change into a hospital gown and have an IV line inserted for sedation.

   • Your vital signs, including heart rate, blood pressure, and oxygen levels, will be monitored throughout the procedure.

2. Sedation:

   • Most patients receive conscious sedation or general anaesthesia, ensuring comfort and relaxation during the procedure.

3. Insertion of the endoscope:

   • Upper EUS: The endoscope is inserted through your mouth, passing down the oesophagus, into your stomach, and into your duodenum.

   • Lower EUS: The endoscope is inserted into your rectum and colon.

4. Ultrasound imaging:

   • The ultrasound probe emits high-frequency sound waves to create detailed images of nearby tissues and organs.

   • If necessary, the physician may perform fine-needle aspiration (needle biopsies) to collect a sample of tissue for further analysis.

5. Duration:

   • Depending on complexity and whether biopsies are required, the entire procedure typically takes 30 to 60 minutes.

What to expect after endoscopic ultrasound?

After undergoing an endoscopic ultrasound, here is what you can expect during your recovery:

• Recovery time:

  • You will be monitored in a recovery area until the effects of sedation have fully worn off.

• Post-procedure effects:

  • If the procedure was performed through the mouth, you might experience a mild sore throat.

  • You may feel bloated or gassy due to the air introduced during the procedure.

• Resuming activities:

  • Avoid driving, operating machinery, or making important decisions for 24 hours after sedation.

• Diet:

  • If no additional procedures were performed, you can usually resume eating once you are fully awake and alert.

These symptoms typically resolve within 24 hours. It's advisable to take it easy for the rest of the day and resume work or other activities the next day.

What complications can happen?

While EUS is generally safe, potential complications include

• Bleeding:

  • Bleeding is more likely to occur after fine-needle aspiration or biopsy.

• Infection:

  • Although rare, infections can occur after tissue sampling.

• Perforation:

  • There is a small risk of tearing the lining of the digestive tract.

• Adverse reaction to sedation:

  • You might face issues like breathing problems, low blood pressure, or allergies.

• Pancreatitis:

  • If the pancreas is evaluated or biopsied, there is a potential risk of developing pancreatitis.

Contact your doctor immediately if you experience any of the following symptoms:

• Severe abdominal pain or chest pain

• Fever or chills

• Having black or dark-coloured stools

• Difficulty swallowing

• Persistent vomiting

FAQ

Is an endoscopic ultrasound painful?

EUS is generally not painful due to sedation, which ensures comfort during the procedure. Some patients may experience mild throat soreness or abdominal discomfort afterward, but these symptoms are temporary.

How long does it take to recover from an endoscopic ultrasound?

• Initial recovery:

  • Typically 1-2 hours after the procedure, during which you will be monitored.

• Full recovery:

  • Most people can resume normal activities the next day. However, to be safe, you should avoid driving or making important decisions on the day of the procedure due to sedation effects.

What diseases can be detected by an endoscopic ultrasound?

EUS helps diagnose and stage various conditions, including:

• Cancers:

  • Esophageal, gastric, pancreatic, lung, and rectal cancers.

• Pancreatic disorders:

  • Pancreatitis, cysts, and tumours.

• Gallbladder and bile duct diseases:

  • Bile duct stones, blockages, and tumours.

• Lung conditions:

  • Lymph node assessment for lung cancer staging.

• Gastrointestinal lesions:

  • Submucosal tumours, cysts, and infections.

Which is better, MRI or endoscopy?

• EUS:

  • This test provides detailed images of the GI tract and allows real-time tissue sampling via biopsy.

• MRI:

  • It offers non-invasive, whole-body imaging without sedation but may not provide as much detail for certain gastrointestinal and pancreatic conditions.

The choice depends on the clinical situation; EUS is preferred when tissue sampling or precise tumour staging is needed.

What are the key therapeutic benefits of EUS in managing medical conditions?

Endoscopic ultrasound (EUS) offers the significant advantage of treating various medical conditions without the need for incisions or surgery. This innovative procedure can effectively address issues such as:

• Drainage of pancreatic cysts,

• Aspiration of fluid-filled spaces in the abdomen,

• Management of bleeding in the digestive tract caused by a burst blood vessel,

• Treatment of pancreatic diseases through nerve blocks, and

• Various ablative therapies.

Can I eat after endoscopic ultrasound?

Yes, in most cases, you can eat after the sedation effects have worn off.

• If your doctor performed a biopsy or fine-needle aspiration, they might recommend waiting a few hours or starting with soft foods.

• Always follow your provider’s specific dietary instructions post-procedure.

How painful is endoscopic ultrasound?

EUS is minimally uncomfortable, as sedation or anaesthesia ensures you are relaxed and pain-free during the procedure. You may feel a sore throat or mild bloating afterward, but this condition is temporary and typically resolves quickly.

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations based on your medical conditions, request an appointment with Thomson Medical.