Sponsored by Innovatus Imaging
By Ted Lucidi, CBET
Trans-esophageal echocardiography (TEE) probes. Just saying those terms can sound intimidating. They were to me at one point in my career. As an in-house service engineer for over 20-years, who supported diagnostic ultrasound, I really didn’t understand them. As much experience as I had within ultrasound and the number of OEM training schools I had attended, TEE probes were a topic never really presented and a device type rarely encountered. I can say that the only times that I handled them was when they failed, and it was always a priority to obtain a replacement. I thought that this month’s TechNation article could introduce readers or reacquaint HTM professionals with these devices.
TEE probes (See Photo 1.) are considered a specialty-type of ultrasound probe and their development was out of pure need. A TEE study is performed when a standard, trans-thoracic echocardiography (TTE), study is inconclusive. Patients with chronic obstructive pulmonary disease (COPD), obesity or a condition known as barrel chest have physiologies that may limit visibility of cardiac structures using traditional ultrasound techniques. The challenge with ultrasound is that there is a tradeoff between resolution and penetration. To adequately penetrate the thoracic cavity of a patient with barrel chest, resolution can be compromised, thus potentially impacting the accuracy of a diagnosis. There needed to be a method or tool developed to obtain high-resolution cardiac images that was not limited by a patient’s physiology. Similar limitations exist within OB-Gyn and urological ultrasound and are the reasons for which endo-cavity probes were developed. Necessity was, once again, the mother of invention.
Similar to standard probes, TEE probes have an acoustic lens, acoustic array, scanhead electronics, a wiring harness, connector electronics and a system connector. No different, right? Hardly. All of the components within a standard probe need to be miniaturized and attached to the end of an assembly that can be inserted in the esophagus (see photo 2). The array and scanhead electronics are located in the distal tip at the end of a flexible insertion tube. The esophagus is positioned directly behind the heart, which provides an ideal depth for obtaining higher-resolution images. To obtain various cross-sectional images, the distal tip can be flexed in four directions using knobs on the control housing. Buttons on the control housing allow the image orientation to be adjusted (either mechanically on 2D TEEs or electronically on 3D TEEs). The combination of articulation and image orientation allow cardiologists similar freedoms as adjusting the position and angle of a standard trans-thoracic probe.
Wear and tear on a TEE probe are much higher than that of any other type of ultrasound probe. The probe is repeatedly exposed to acidic GI fluid for up to eight hours or more. TEE studies can last as little as 30 minutes for outpatient or bedside studies, or as long as eight hours during a surgical procedure such as a valve replacement. TEE probes must also be high-level disinfected after each use, which is typically performed via immersion in harsh chemical solutions.
Our research shows that after about 100 to 150 uses, the rubber-like materials on a TEE probe, specifically the bending rubber, tend to become more brittle and more apt to perforate if they contact a sharp object. Add to this the fact that the distal tip, bending section and insertion tube may be bitten, dragged across sharp teeth or accidentally damaged during transportation. No bite guard ever created can protect a TEE probe from the gag reflex of a frightened patient who awakens during a TEE study.
The process of disinfecting a TEE probe, with a break in physical integrity, is one of the most-frequent modes of failure. As such, about 50 to 60% of all TEE probes that arrive at our facility present with gross fluid invasion because of some type of physical damage or improper use. Once fluid (bodily or chemical disinfectant) enters the probe, catastrophic electro-mechanical failures will occur. It only takes a few hours for chemical agents to begin corroding the electro-mechanics within the probe and energizing a fluid invaded probe on a scanner may not just damage the probe, but also induce thousands of dollars of damage to the scanner.
TEE probes are typically only in use at larger metropolitan health care facilities with heart failure programs. Smaller metropolitan facilities, or rural and general hospitals, may not have a single TEE probe. For those that do, expect only about 10% of your probe volume are TEEs. That being said, supporting TEE probes may cost as much as supporting the other 90% of the facility’s standard probes. OEM replacement TEE probes can cost anywhere from $20,000 to $40,000 apiece and you can expect a 70% failure rate per probe per year.
There is good news! By using Innovatus Imaging, even catastrophically damaged TEE probes can be restored. There are multiple TEE probe models on which we have 100% repair capabilities and expect repair costs to be only a fraction of the replacement cost (starting at only $500). Some repair providers offer to dehydrate fluid invaded probes and take the “dry it and try it” approach. Our goal in addressing fluid invasion is to REPLACE any and all affected components, thus restoring performance. It’s what allows us to offer a six-month warranty on all TEE probes (repaired or exchanged). It’s one of the industry’s longest warranties.
Next month, we’ll expand this discussion to further illustrate the cost savings associated with adding TEE probes to your PM program. Email customercare@innovatusimagaing.com or call 844-687- 5100 to arrange for your solution today.
Ted Lucidi, CBET, is a clinical marketing and commercialization specialist at Innovatus Imaging.
