I had no choice. I began doing ultrasound-guided biopsies in 1979 during my fellowship and there was no such thing as a biopsy guide. We had to figure out how to do it freehand ourselves and gradually, with the help of colleagues at other institutions, refined the technique. When the needle guide was developed, I found it limiting and awkward and became concerned about some of its risks as I saw others struggling with it.
Before you dismiss this as the ravings of an over-the-hill radiologist who can’t learn new tricks, my yield and adverse effect rate has been comparable (I think better), our technologists generally have preferred working with me on biopsies because my freehand technique is quicker and less uncomfortable for the patient. I have even gotten some of my colleagues to sometimes adopt my approach despite their being taught the dogma that the guide is mandatory for deep abdominal biopsies.
Can you really set the needle guide on the shelf?
There has been a myth in our department that I am the only one who CAN do all ultrasound-guided biopsies freehand (which I think is an excuse for others not to try). Anyone who really knows me understands that is absurd. I am totally uncoordinated and I cannot conceivably have some unattainable innate fine-motor skill for this. The technique I will describe can be done by anyone with basic guided-biopsy skills if you are willing to be bold. But why bother? Because I believe that this approach decreases the time to do procedures, decreases patient risk, increases flexibility and decreases cost.
Of course, I am only referring to deep abdominal and pelvic transcutaneous biopsies here. There is no question that there are situations, such as endovaginal or transrectal biopsies where a specialized needle guide is necessary. Also, I will save discussing principles of biopsies, needle choice, optimizing and saving the specimen, patient communications, timeouts, etc. for now, Instead, I will focus on why and how to do freehand biopsies and how the needle guide and the freehand techniques compare.
Typical ultrasound guide (light blue arrow) with expected needle trajectory (yellow arrows). Images adapted from: D. Plut, S. Ponorac, D. Vidmar-Bracika “Diagnostic value of ultrasound-guided fine-needle aspiration cytology in diagnostics of solid renal lesions” ECR 2013 (view poster here)
What about small and subtle lesions?
Isn’t it necessary to use the guide for small lesions? The needle guide reliably takes you right to the lesion and assures a successful specimen, right? Can you needle guide-users say that is your consistent experience? What about the difficult-to-reach lesions? Can you see the subtle lesions as well after you put on the sheath with the gel inside? I will discuss these situations more later.
Why bother to learn how NOT use the guide?
Why did we need the guide? When I began doing biopsies, real-time ultrasound was truly primitive and deserved its moniker: “ultrasmoke.” Finding the needle was a serious challenge. Even holding the large transducer and awkward needles were limiting. We needed help! The inventors of the needle guides had great ideas and so help arrived. However, today, the needle is much easier to see and the needle systems we use are much lighter and more efficient. Nevertheless, many still believe that they are nearly obligated to use the “time-tested” help that I think we no longer need.
Using the needle guide makes sense, right? It decreases the time to do the procedure because the needle goes right to the lesion, it increases precision and minimizes the need for repeat biopsies…except, in my experience, it doesn’t. It seems to be such an imperative for some that I have even seen the guide used for large lesions bulging the skin, for which you really don’t even need ultrasound or for fine needle aspirations of superficial thyroid nodules. This series is about how not to be the person that does that.
In part 2 of this series, I will start describing planning, prepping and administering local anesthesia for freehand biopsies and contrast those techniques to using the needle guide.
In this series:
- part 1 - introduction
- part 2 - planning and preparation
- part 3 - approach and visualisation
- part 4 - the biopsy
- part 5 - additional benefits & conclusion
- survey results
Lincoln L. Berland, MD is Professor Emeritus of the Abdominal Imaging Section of University of Alabama at Birmingham.
NB: Opinions expressed are those of the author alone, and are not those of his employer nor of Radiopaedia.org.