What is endoscopic ultrasound?
Endoscopic ultrasound (EUS) is a state-of-the-art technology that combines endoscopy and ultrasound. EUS allows highly detailed examination of each of the 5 layers that line the walls of the intestinal tract. This special capability is very important in determining the depth of esophageal, stomach, rectal, and pancreatic cancer invasion prior to surgery and chemotherapy. EUS is also invaluable for evaluating abnormal “bumps” growing from underneath the first layer of the intestinal wall lining. It also allows visualization and minimally invasive biopsy of internal organs such as the pancreas, bile duct, gallbladder, liver, spleen, lymph nodes, and lesions in the chest cavity. The high resolution of EUS enables detection of small lesions less than 1cm in size such as early cancers, lymph nodes, and bile duct stones that are frequently missed by CT, MRI, and PET scans. EUS is now considered one of the most essential and cost-effective techniques in the assessment of a wide range of diseases.
EUS is only performed by a few specialists in the country and therefore is not widely available. Sequoia is proud to be among the few distinguished centers in the country to offer the innovative technology for advanced patient care.
Dr. Ann Chen is Sequoia's EUS specialist. Please search for her on our online Find a Doctor tool.
Talk to your physician for more information.
When is EUS useful?
EUS is a very sensitive test. It may be helpful in obtaining more information for a diagnosis when other tests are inconclusive. It is also very important in deciding what the best course of treatment should be (e.g.. when and if to start chemotherapy or surgery) in both precancerous and cancer diseases.
What is cancer staging and why is is important?
For cancer patients, staging describes the extent of a patient’s cancer, how early or advanced it is. Staging is important because it helps your doctors plan treatment (e.g. surgery or not and if so, should it be performed before or after combination chemotherapy and radiation therapy or no combination therapy at all?). EUS is the most accurate non-invasive way to determine the local extent of many gastrointestinal (GI) cancers (T stage), such as those listed above. In addition, EUS can be used to biopsy many tumors or lymph nodes (N-stage) close to the digestive tract.
Benefits and Risks
Benefits
As a non-surgical, minimally invasive alternative for diagnosing gastrointestinal diseases, EUS has several benefits:
- It is a short procedure (30 minutes to 1 hour) performed on an outpatient basis with light sedation and anesthesia, reducing risks and speeding recovery.
- It can provide more accurate diagnosis and staging than CT scans, MRI, or PET scans thereby saving patients from unnecessary surgery or chemotherapy and improve treatment outcomes by helping doctors chose the best course of therapy.
Risks
As with any medical procedure, complications can occur but are very rare. EUS is generally considered a relatively safe procedure. The risks include:
- A mild sore throat for a day or two after EUS generally relieved with cough drops.
- A very rare chance (less than 1%) of infection, bleeding, or tear of the intestinal wall lining requiring surgery.
Additional links:
http://www.asge.org/PatientInfoIndex.aspx?id=380
www.cancer.gov http://www.mayoclinic.org/endoscopic-ultrasound/
