Interview with an expert, Assoc. Prof Greg Goodman
I’m really excited to have secured an interview with Assoc. Prof Greg Goodman, International Dermatology maestro. He is an Australian who has always been at the forefront of the cosmetic industry internationally, and I’m delighted that he is now focusing his efforts on giving back so much to our industry by offering online training (Facecoach)
I’m going to be hitting Dr Goodman with the toughest questions about this difficult topic, “dermal fillers and blindness”.
Dr Goodman thank you for being my guest.
Dr. N: Is it correct that there have been approximately 100 cases of blindness worldwide associated with injection of dermal fillers and fat?
Dr. G: It is quite hard to come up with an exact number as many case reports and reviews may be crossing over in terms of patient reporting. However, one Korean study on its own discussed 44 cases and another Chinese study discussed 13 cases and a large article review discussed 32 cases. We are also only seeing here the reported cases and I would imagine many would not find their way into published reports.
Of these fat and all fillers are represented. It appears that fat is the most problematic if embolisation occurs
Dr. N: Can you explain the science behind this devastating complication?
Dr. G: It would appear that the injection of filler finds its way via a branch of an artery against the pressure of the artery into more the more main vessel and on letting go of the pressure the main branch pressure forces the filler back down the vessel under the restored arterial pressure into all the tributaries supplied by that vessel effectively blocking these. Think of a tree and injecting from the most peripheral branch up to the trunk then with release all the tree limbs budding of that trunk are blocked. If this happens in the ophthalmic division of vessels the retinal artey may be one of these branches affected on release of the injection pressure.
Dr. N: Which areas on the face could be considered the most risky areas for this complication? Which arteries are the ones most at risk?
Without doubt the central part of the face is the most risky in the distribution of the facial and angular arteries as it courses superficially up across the mandible anterior to the masseter muscle to wind up to the corner of the nose where it gives off the labial arteries en route and is vulnerable with lip and nasolabial fold injections, then giving of alar branches and in some people continues up the side of the nose as the angular artery and anastomosing with supratrochlear branches of the ophthalmic artery that may feed into other vessels that feed the eye. The temple and brow are also sites where entrance to the ophthalmic artery branches may occur. Reports of blindness have occurred from lip, nose (tip, side wall and dorsum), nasolabial fold, glabella and forehead and temple.
Dr. N: In your opinion, are there areas on the face that injectors should just never inject?
Dr. G: It is probably not quite that simple, its possibly about injection technique and understanding where the tip of your needle or cannula is anatomically both where you are and how deep you are – there are areas like glabella that are so high risk that they need to be vetoed by anyone with a needle unless very superficial and with special techniques. There are others such as side wall nose that need a lot of care. There are some like nasal tip and superior nasal ala that are close to “no go” areas. There are some like brows and temples that need special techniques and solid understanding of the anatomy.
There are areas that I would be very nervous to use a needle or fine cannula.
Dr. N: Needles vs cannula: Is there a size of cannula where it could be considered absolutely safe that there can be no cannulation of a vessel or risk of blindness? In the early days of cannula use, I personally had a case of necrosis following injection with a 27 gauge cannula, would it be correct to say that larger cannulas are safer than smaller cannulas? Do you have a preference in cannula size?
Dr. G: I think probably there is no such thing as an entirely safe gauge cannula but 22 and thicker are starting to become pretty safe. I personally have heard of a 25# cannula being involved in necrosis. I am starting to like 22# cannula for many higher risk parts of the face. The problem may be that often vessels will have stabilisation points especially where vessels bifurcate and branch. These points may allow the vessel enough rigidity to be pierced by cannulae especially those with sharp ends or fine calibre.
Dr. N: With fat injection, is a blunt cannula now always used for injection of the fat, if so, what gauge is typically used? With the history of fat transfer and blindness, do we know if sharp or blunt cannulas were used in these cases, and the gauge?
Dr. G: If blunt cannulae are not being used they should be. There was a stage where many were using 22# needles but I think maybe that has passed. Most fat transfer is done with 18# cannulae but I am unsure what guage or injection/cannula was used in the blindness cases.
Dr. N: One problem that I am dealing with personally as an injector, is wanting to inject in the area on the superomedial orbital rim, in the region of the supraorbital artery and the supratrochlear artery, but not being able to find a way to do it safely. So I am leaving patients with an aged look there, which is frustrating. Can you think of any way around this problem?
Dr. G: Excellent question. I think the only way is to be quite superficial with a broad cannula with very slow injection and multiple passes – very hard to do and produce an even result. I know there are some that use a needle here but I wouldn’t recommend that.
Dr. N: Is there a role for injection of local anaesthetic with adrenaline prior to treatment to reduce risks of vascular complications?
Dr. G: Maybe, but then you have to contend with distinguishing the blanched appearance of the adrenaline effect. The blanching does not really look that much like the blanching from intra arterial injection but it may cause some confusion.
Dr. N: What is your personal technique for temple injection including relevant surface anatomy? Does facecoach have a training video on this topic?
Dr. G: Yes FaceCoach does have a video on temple injections. I either advocate deep (1/2 inch) injection in the temple with a bolus but still moving and slow injection. Negative aspiration should not be relied upon. Otherwise large bore 22# cannula superficially is OK too but may make the veins more prominent
Dr. N: I consider the aged forehead a currently undertreated area, when you consider how much it changes in structure with ageing. Please share your technique with forehead injections. What are the no-go zones (also please include relevant surface anatomy), and what are the safer zones? Does Facecoach have a training video on this topic?
Dr. G: The lateral forehead can be approached often with the brow. The central forehead should not be treated in the glabella area with a needle. Probably the best way is either from laterally or superiorly with a large bore cannula. An alternative is deep filler more superiorly raising a bolus and milking down into the forehead, however, a cannula is probably safer and the larger the better. There are some FaceCoach videos on this
Dr. N: In terms of injecting technique and preventing ischaemic events, would I be correct is saying that location of the needle tip is important, as is lower volume and slow injecting? Is constantly moving the needle tip of benefit, if so, why?
Dr. G: Yes slow injection so the pressure hopefully is not overwhelming the systolic arterial pressure that way not allowing retrograde filler implantation and subsequent embolisation. Continually moving your needle is essential I believe as if you are in a vessel a minute move will take you out of the vessel limiting your injection that may be intravascular. We are probably always in and out of vessels so sitting still and injecting a bolus with or without aspiration is likely to be problematic.
Dr. N: If the worst thing happened, and vision loss occurred during dermal filler injection, what is the protocol? What is the prognosis?
Dr. G: One can try massaging the eye, but the most important thing to do is get an ophthalmologist immediately. You only have 90 minutes to save vision. An ophthalmologist will try a number of things to maximise the outcome but the prognosis is pretty grave. We do not have a good antidote here.
Dr Greg Goodman
Dermatology Institute of Victoria
8-10 Howitt Street,
South Yarra, Victoria 3141
Phone: +61 3 9826 4966