Endoscopic Ultrasound (EUS)

Endoscopic ultrasound (EUS) is a medical procedure that combines endoscopy and ultrasound to obtain images of the digestive tract and its surrounding tissues and organs. It is used to diagnose and treat various conditions, including gastrointestinal cancers, pancreatic diseases, and liver disorders.

How EUS Works

EUS uses a flexible tube called an endoscope that is equipped with a high-frequency ultrasound probe at its tip. The endoscope is inserted through the mouth or rectum and guided to the area of interest. The ultrasound probe emits sound waves, which bounce off the tissues and organs, creating detailed images on a monitor.

Types of EUS

There are two main types of EUS:

• Radial EUS: This type of EUS uses a rotating ultrasound probe to obtain 360-degree images of the surrounding tissues and organs.
• Linear EUS: This type of EUS uses a linear array ultrasound probe to obtain images in a single plane. Linear EUS is often used for therapeutic procedures, such as fine-needle aspiration (FNA) or fine-needle biopsy (FNB).

Indications for EUS

EUS is used to diagnose and treat various conditions, including:

• Gastrointestinal cancers, such as esophageal cancer, gastric cancer, and pancreatic cancer
• Pancreatic diseases, such as pancreatitis and pancreatic cysts
• Liver disorders, such as liver cancer and cirrhosis
• Submucosal lesions, such as gastrointestinal stromal tumors (GISTs)
• Inflammatory bowel disease, such as Crohn's disease and ulcerative colitis

Benefits of EUS

The benefits of EUS include:

• High-resolution images: EUS provides detailed images of the digestive tract and surrounding tissues and organs.
• Minimally invasive: EUS is a minimally invasive procedure that does not require surgery or external incisions.
• Accurate diagnosis: EUS can help diagnose conditions more accurately than other imaging modalities, such as CT scans or MRI.
• Therapeutic capabilities: EUS can be used to perform therapeutic procedures, such as FNA or FNB, to collect tissue samples for diagnosis or treatment.

Risks and Complications of EUS

As with any medical procedure, there are risks and complications associated with EUS, including:

• Bleeding: Bleeding can occur during or after the procedure, especially if a biopsy is performed.
• Infection: Infection can occur if the endoscope is not properly sterilized or if the patient has a weakened immune system.
• Perforation: Perforation of the digestive tract can occur if the endoscope causes a hole in the wall of the intestine or stomach.
• Pancreatitis: Pancreatitis, or inflammation of the pancreas, can occur after EUS, especially if a biopsy is performed.

Preparation for EUS

To prepare for EUS, patients should:

• Fast for 6-8 hours: Patients should not eat or drink anything for 6-8 hours before the procedure to ensure that the stomach and intestines are empty.
• Avoid certain medications: Patients should avoid taking certain medications, such as blood thinners, for a few days before the procedure.
• Inform their doctor about medical conditions: Patients should inform their doctor about any medical conditions they have, such as diabetes or heart disease.

What to Expect During EUS

During EUS, patients can expect:

• Sedation: Patients will be given sedation to help them relax and reduce discomfort during the procedure.
• Insertion of the endoscope: The endoscope will be inserted through the mouth or rectum and guided to the area of interest.
• Ultrasound imaging: The ultrasound probe will emit sound waves, which will create detailed images on a monitor.
• Breathing and swallowing instructions: Patients may be asked to hold their breath or swallow during the procedure to help the doctor obtain clear images.

After EUS

After EUS, patients can expect:

• Recovery time: Patients will need to rest for a few hours after the procedure to allow the sedation to wear off.
• Follow-up care: Patients should follow up with their doctor to discuss the results of the procedure and any further treatment or testing that may be needed.
• Discomfort or pain: Patients may experience some discomfort or pain after the procedure, which can be managed with medication.