Your doctor may have recommended EUS because in many cases, it lets us determine that your symptoms are caused by an anatomical abnormality or a benign or easily treated condition. Even if a tumor is involved, there are many effective new treatments that require the precise information we can provide with EUS.
My staff developed a "When Accuracy Counts" to address some of the most common questions our patients ask. If you have others, do not hesitate to call us. We'll do whatever it takes to make sure you have the information you need.
With all best wishes,
Harry Snady, M.D., Ph.D.
Endoscopic Ultrasonography, or EUS, joins the medical technique of endoscopy with the high frequency sound-wave technology you may know as ultrasound. This state-of-the-art combination allows the doctor to "microscopically" examine tissue not only within the digestive tract, but also surrounding it. Like endoscopy, EUS uses a flexible tube called an endoscope, which works like a periscope. The doctor inserts this tube into the digestive tract through the mouth or the rectum to examine internal organs and photograph and videotape the findings. EUS is as comfortable as regular endoscopy, although it takes longer because it is more precise, and because there are more details for the doctor to examine and interpret.
Finding an abnormality with regular endoscopy is like seeing the tip of an iceberg. Endoscopy shows only the inner surface of the digestive tract and cannot show the abnormality beyond the visible surface. But in the same way a ship's sonar can depict the whole iceberg under water, the high-frequency of EUS reveals the full extent and nature of abnormalities, including information that is critical to accurate diagnosis and optimum care. In skilled hands, EUS can even locate abnormalities not detectable by any other means.
EUS is done from inside the body, near or even touching the targeted area, so that a finer, higher frequency imaging energy can be used. Sonogram, MRI and CT scan must image internal organs from outside the body, losing resolution in the process. The superior resolution of EUS shows all five layers of the digestive tract wall, almost like a microscope; no other test can see the intestinal wall as well. Because it is video-based, EUS also provides a seamless stream of data, eliminating the unseen and unrecorded gaps between the still images of scans.
Comparing these other tests to EUS is like comparing an enlargement of one person's eye from a class photo to a high-resolution video close-up of just an eye. Regardless of how big the enlargement is, the graininess makes it impossible to count the eyelashes. In a video close-up, you can not only count the lashes, but you can determine their length, follow the eye as the head turns, see how often the eye blinks, and so on. EUS is more like a video close-up than like a still photo enlargement.
The theory behind thin-slice CT is that by taking more pictures closer together, a small tumor or abnormality is less likely to be missed in the gaps between shots. But such techniques do not overcome the resolution problem: more pictures don't help if the resolution is too grainy to detect a small abnormality in the first place.
Here's an example of the kind of difference EUS can make: Using EUS, Dr. Snady has a proven 90% accuracy rate for diagnosing potentially removable pancreatic tumors. CT scan accuracy is only about 50%, the same as flipping a coin.
Even surgery does not provide an accurate diagnosis in about 5% of cases. Using EUS, Dr. Snady has occasionally found malignancies that surgeons have not. That's because surgeons can see only what is visible to the naked eye. With its microscopic focusing ability, EUS can penetrate the layers of the GI tract to detect malignancies that may not otherwise be confirmed until after surgery, when the abnormal tissue that was removed is actually examined with a microscope.
In the past, an accurate diagnosis made little difference for treatment. Since there were few options, the treatment would not have changed with the added information. For example, in cases where localized pancreatic cancer is suspected, it has long been common for patients to undergo diagnostic surgery with the intent that if a tumor is found, it would be removed if possible. In reality, less than half of tumors are removable this way. Unfortunately, even when the tumor is removed at diagnostic or initial surgery, there is little or no improvement in lifespan. In addition, patients are further burdened with an inconvenient and often lengthy recovery period and sometimes hospitalization, so that even if additional treatment is indicated, it cannot be given.
Today, subtle changes in treatment planning may improve patients' quality of life and outcome, many times reducing the time and expense involved in treatment. In cancer cases, Dr. Snady's EUS findings will help determine which of many new treatments to pursue, including new combinations of chemotherapy and radiation therapy that have been shown to dramatically shrink tumors and increase survival. Top surgeons and medical teams know that using these approaches prior to surgical removal makes surgery significantly more effective. Accurate EUS results are critical to using these new approaches to full advantage, because an abnormality can be accurately diagnosed and characterized without surgery. Then the patient and medical team can make an informed decision as to the best course of action.
In developing a treatment plan, key considerations are whether surgery is required, and when it would be most effective. When EUS findings indicate that surgery is called for, EUS images provide crucial information for the surgeon. As a result, unproductive or unnecessary surgery is avoided, operating and recovery time are kept to a minimum, and the best possible patient results are ensured.
In 1992, a leading medical journal published a report by Dr. Snady showing that the accurate diagnosis arrived at through his EUS findings changed the course of medical treatment for more than one-third of patients, and altered treatment plans in about three-fourths of cases. Importantly, patients' overall risk was reduced. Changes typically involved more conservative, less expensive, and less time-consuming treatment, while improving results. Four years after Dr. Snady's report, a joint team of experts from top institutions nationwide were able to attain results similar to his initial findings.
It matters for several reasons. To focus on certain areas of the anatomy, great skill and technical ability is required just to manipulate the EUS instrument. It takes years of experience and a large caseload to reach a high level of expertise. The accuracy of results varies widely depending on the diagnostic skill of the physician, and sub-optimal findings may not provide dependable direction for guiding treatment. An endosonographer must be able to document at least an 80% accuracy in diagnosis and staging to achieve the anticipated 30 - 60% rate of change in treatment plans.
Dr. Snady's extensive experience and research in sonographic interpretation, along with his clinical skills, allow him an unsurpassed accuracy in diagnosis. He is recognized for his technical ability, his safety record, and his expertise in interpreting sonographic images, and he is often called upon to provide definitive opinions in hard-to-diagnose gastrointestinal (GI) cases. Dr. Snady works closely with your own medical team to discuss treatment options and to help ensure that you receive the best possible care.
Where you have EUS done is also important. Dr. Snady is recognized for having the most experience in the world at performing EUS safely and comfortably in an office setting. Because he does EUS in his own facility, rather than in a teaching hospital, you can be sure that he will personally perform the evaluation. The problems and inconvenience of hospital admissions are avoided, as are the associated hospital fees. The relaxed environment and professional staff have helped achieve a patient satisfaction rate of virtually 100%.
If you have any additional questions about anything to do with your procedure or your condition, don't hesitate to contact Dr. Snady or any member of our professional staff.
© 1999 EUS Imaging, P.C., All rights reserved.