Why use methylene blue ?
Why use methylene blue ?
How can methylene blue assist with endoscopic spine surgery ?
Endoscopic spine surgery is, in many ways, a self-taught skill set. Especially as one advances from beginner to expert. Of course this steep learning curve can really be shortened with proper training and this is why I created the Endoscopic Spine Academy. One main difference between beginner and expert is that the expert knows exactly what they are looking at with the endoscope a majority of the time. The beginner does not have the confidence that experience brings and has to wonder a little more about what is being observed through the endoscope. An important visual aid that can assist both beginner and expert is diluted methylene blue.
Methylene blue is an acidophilic dye that is neurotoxic and can be very helpful in learning and performing endoscopic spine surgery. The reason methylene blue is helpful is because it is acidophilic and it will stain the nucleic acids of any dead cells. This property helps to distinguish viable and nonviable tissues, particularly inside of a disc. Let’s look at three examples.
When a disc is injected with diluted methylene blue (I use 2cc methylene blue mixed with 8cc of normal saline), it will follow any tears or fissures and stain any nonviable tissues or free-floating fragments. These are fragments associated with annular tears and disc herniations. During surgery, if the tissue is blue, it is not viable and probably should be removed. This is certainly true when removing the free-floating fragments causing annular tears. Repetitive debridement of stained tissue from disc material of a painful lumbar disc will give you an idea of how much disc you can expect to remove. Once you have seen how much disc material is present and where to find it (toward the center), the use of the dye is optional.
Another helpful use of methylene blue is to identify a herniated disc in the foraminal canal (foraminal disc herniation). There are tight quarters in the foraminal canal and often the herniation sits on the underside of the exiting nerve root. Since the herniation is usually covered with some annulus, knowing exactly where you are can be challenging, especially if you are a novice.
If the disc is degenerative with a hard consistency, discrimination can even be more challenging. By definition, a disc herniation must be associated with an annular tear. If methylene blue is injected into the disc, it will follow the tear out to the herniation and stain the herniation. This helps to discriminate and determine how much tissue to remove.
The third example where methylene blue can be helpful is to identify and remove the far-lateral disc herniation. The dye will track out through the annular tear to visualize the herniation, but where it really helps is when continuing the removal of stained nonviable tissue under the herniation that might contribute to a recurrent herniation.
The road to becoming an expert can be facilitated with some diluted methylene blue as you begin to make endoscopic spine surgery your specialty.
Onward and Upward