cannulas Archives | The Aesthetic Clinique

What’s More Accurate – Cannulas vs Needles For Dermal Fillers?

There is an ongoing debate among injectors as to what method of injecting fillers is more accurate. The needle pundits state that the needle can inject in any tissue, at any depths. While this is true, is the filler actually placed where they think it is? Cannulas aficionados argument is that cannulas will stay in the plane which they are placed, and are therefore more accurate.

In a paper titled “Precision in Dermal Filling: A Comparison Between Needle and Cannula when Using Soft Tissue Fillers.” by Pavicic, Frank, Cotofan, et all, the debate was studied. There were 10 cadavers studied for supraperiosteal injections. The filler injected was radiopaque. Needles were placed in position using a perpendicular transcutaneous approach. The cannulas were placed in a similar position in the supraperiosteal plane. Using fluoroscopy, the injected material was analyzed in the horizontal and vertical planes.

The results show that in over 60% of the needle injections, the material changed planes (became more superficial) and this was not found in the cannulas group.

The conclusion was that cannula filler placement is more precise because the filler remains in the plane of the intended implantation much more so than needle placement.

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New Research Suggests that Not All Cannulas are Safe!

Cannulas, specifically, blunt microcannulas, can be used to administer fillers by advanced injectors. They a favorable over needles because they have a blunt round tip and are flexible, leading to the following advantages:

Less discomfort – one entry point can serve a large area, thus avoiding multiple dermal penetrations which is more uncomfortable.
Less bruising – the rounded/blunt tip tends to bend around blood vessels rather than nick or penetrate them.
More accurate – a recent study shows that the filler is most likely to be deposited in the area of the exit port vs a needle which has been shown to have filler travel up the shaft (back flow)
Safer – cannulas are less likely to give intraluminal vessel injections because of the blunt tip and therefor less possibilities of vascular compromise and blindness.

However, a recent publication by Drs Pavicic, Cotofana et al. has shown that #4 comes into question with certain cannulas. There study consisted of a total of 294 penetrations of the superficial temporal artery in cadavers using 22, 25, and 27 gauge cannulas and needles. The force applied to enter the vessel was measured for each. The cannulas had statistically higher forces needed to enter the vessel for the 22 and 25 gauge cannulas.

Interestingly, there was no difference in the forces when comparing 27g cannulas and needles.

The conclusion was that a 27g cannula was not safer than a 27g needle when used for filler injections. While 27g cannulas can be used, it is up to the injector to realize these are not safer than needles and to take the appropriate safety measures during treatments.

(Article: Plast Reconstr Surg. 2019 Mar;143(3):504e-512e. doi: 10.1097/PRS.0000000000005321)

Why are Blunt Microcannulas the Obvious Choice for Dermal Fillers?

Dermal fillers are becoming increasingly popular worldwide. Contouring of the face, restoring volume loss, enhancing features such as lip plumping can all be obtained with very little downtime. Just 15 years ago, surgery was the only way these enhancements could be performed. There are some minor complications associated with fillers such as pain, bruising, swelling which are fairly common (>70%) and some major risks such as vascular occlusion, blindness, and stroke which are much less common.

The most common method to administer fillers is using the needle which is packaged with the product. While needles are very easy to use, in the author’s opinion, they are more risky and lead to more downtime versus the blunt microcannula technique. Microcannulas were introduced to the United States about 8 years ago from Europe. These were a smaller version of the already widely cannulas which were used for fat transfer. When compared with a needle, cannulas are more flexible, longer, and their tip is more rounded. The following advantages are found with cannulas:

Fewer dermal penetrations – cannulas are introduced through only a small number of pilot holes.
Less discomfort – the dermis contains more pain fibers than the deeper tissues. The injections with cannulas are below the dermis, so discomfort is less.
Less trauma to tissues/less bruising – because of the rounded tip, the cannula is less likely to nick blood vessels leading to less bruising and swelling.
Faster procedure times – With an experienced cannula user, placement of filler is done very quickly and efficiently. (Cheek/tear troughs <5 minutes per side, lips <5 minutes)
Less vascular occlusion risks – While cannulas aren’t 100% safe, the risks of injecting into a blood vessel are less because entering a vessel is more difficult with the rounded tip and flexible shaft. This is true for the larger gauge cannulas such as 22, 23, and 25. Recent studies by Dr. Pavicic and Cotofana have shown the 27g cannulas have the same force needed to enter a vessel as a 27g needle and therefore should not be used.

Galderma recognized the advantages of microcannulas and became the first company to get FDA approval for their use with Restylane Silk in lips in 2017, and for Restylane Lyft for the cheeks in 2018. While less than 10% of providers use cannulas in the US, there is a push by the top injectors to encourage their widespread use.

Dr. Weiner has been using microcannulas since 2012 and is one of the most experienced cannulas injectors in the US. He is one of the leading trainers for Galderma, particularly for their cannula trainings. He is available for private trainings in off label use of fillers – face/body. There are shadowing opportunities as well as week long internships opportunties. For inquires, please email: info@theclinique.net or steve@stevenfweiner.com

2019 UPDATE: State-of-the-Art Acne Scar Treatments

Acne scarring has significant debilitating effects on one’s overall self-worth and confidence. Millions in the US are affected. There have been improvements in techniques and energy devices in past few years which have led to better outcomes for acne scar treatments.

Subcision – This is process of breaking up deeply tethered scar bands associated mainly with atrophic/rolling scars. Subcision has be performed for acne scars for decades and just using this procedure alone has proven to lead to significant acne scar improvements. Recently there have been a couple publications suggesting that cannula subcision had better outcomes, less downtime, and less discomfort than the traditional method of using a Nokor needle. A cannula has a blunt tip so it is also safer – less chance for cutting a nerve or blood vessel than the knife-like edge of the Nokor needle. In the study, both patients and the performing doctor rated the results better when using the cannula. Subcision is particularly important, in Dr. Weiner’s opinion, to be performed prior to any energy device for tethered scars. This is based on the fact that RF and laser will preferentially travel through collagen – which is high is water content – than fat or most other tissue. Scars are predominantly collagen, so it makes sense to cut the connection of the scar to the deeper tissue. Through personal communication with Dr. Davin Lim, biopsies he performed have shown scar band that reach the deeper fat pads from tethered acne scars. Transmission of the energy through the scar can theoretical lead to collagen contraction and deepening of the tethered scar. Sometimes fillers are placed at the time of the subcision to improve the volume loss associated with the scarring. Some hypothesize that putting a “spacer of filler” might improve results as well. Dilute lidocaine during the initial passes allows for this procedure to be well tolerated.

TCA CROSS – TCA (Trichloroacetic Acid) is a chemical peel used to improved acne scarring by placing minute quantities in the scar using a toothpick. CROSS stands for Chemical Reconstruction of Skin Scars. The most common use of this procedure is for ice pick and small boxcar scars. The process of causing a controlled chemical burn, allows for the body to heal from the deepest part of the scar towards the skin surface. This makes the scar smaller in diameter and shallower. Usually a series of 3-6 treatments are needed, with 3-4 weeks between treatments. There will be some mild scabbing for a few days which needs to be kept moistened for best results. Risk include widening of the scar or post inflammatory hyperpigmentation (PIH).

Radiofrequency Microneedling – This technology (RFM) has been available in the US for about 6 years and has revolutionized acne scar treatment. Using needles which are insulated, energy is delivered into the scar tissue directly and bypassing the epidermis, for the most part. The insulation protects the skin surface from heating so darker skin type individuals are at much less risk of PIH (post inflammatory hyperpigmentation) vs a laser treatment. The needles allow for deeper penetration than lasers as well. Overall, downtime is less than ablative lasers in most individuals (when insulated needles, proper technique, and appropriate settings are used). With acne scarring affecting darker skin types disproportionately, this is an excellent alternative to lasers. The Genius has recently been FDA approved and is now the “best of bread” RF microneedling device. There is now impedance feedback from the needles which allows for improved and exact energy delivery. The resistance in the tissues being treated is measured and this is important because throughout one’s face, there are differences, as well as between different individuals. Also, as tissue are heated or subcised, the resistance changes. Prior to Genius, there was no idea of how much energy was being delivered. There is now an accurate total energy for each pulse and a cumulative total. Other improvements include needle design-sharper, stronger motor, and feedback regarding quality of each pulse fired.

There is a myth that needs to be busted. Deeper does not mean better for acne scars.

The needles must stay within the scar for best results. If the needles go beneath the dermis, there is a risk for heating the fat and fat loss. Let it be known that the actual depth of the needles in most RFM devices is less than the settings, and becomes less accurate, the deeper the settings are. There is inherent resistance of the skin to penetration and many needles aren’t sharp enough or motors aren’t strong enough to get to the desired levels in the time required. This has also been addressed with the Genius and it’s depths are very accurate after extensive testing.

In addition, higher energy levels on any device which doesn’t monitor impedance, can actually result in very little energy delivered. Once the tissue is heating beyond a critical level, the resistance becomes so high that energy output cuts off. However, when higher energy levels are desired when using the Genius, the energy is adjusted to the increasing impedance and it is successfully delivered.

Fillers – Fillers are a very integral part of improving acne scars. They are extremely useful for the atrophic scars and the lipoatrophy associated with these scars. The aging process leads to dermal thinning and fat atrophy, which makes the acne scars appear worse, even if active acne has long been controlled. Fillers need to be injected deeply for correcting large areas of volume loss and superficially in minute quantities for focal defects. A hyaluronic acid filler will give about 12 months of improvement vs Bellafill which can give near permanent improvements. Bellafill does require a skin test to see if one has a allergy to the bovine collagen (0.5% chance) which needs 3-4 weeks to determine. There is some who feel fillers in areas of subcision will prevent re-adhesion of the scars. Most failures from other treatments are related to not recognizing the need to fillers to improve the acne scars.

Lasers – Erbium/CO2 ablative lasers still are beneficial for acne scars but have more downtime and risks vs RFM. Deeper skin imperfections are not improved with lasers and require fillers. These devices are best reserved for more superficial scars, mainly boxcar scars. Non ablative lasers are less affective but safer and in the author’s opinion give very minor results.

Microneedling – Also know as “Collagen Induction Therapy” CIT, has become popular in recent years. There are rollers available for home use and then there are medical grade devices which go to depths of 2mm or deeper and create thousands of penetrations per second. Rollers should be not be used at home for 2 reasons – questionable sterility at home and they tear tissue more than the in-office devices. Often these treatments are combined with topicals and PRP. It is highly recommended to not use any products on the skin which would normal not be injected. There have been many cases of infection and granulomas from these practices. Even when done in the office with PRP or amniotic membrane products, the efficacy of this procedure is minimal, and should be reserved for only mild acne scarring.

PRP/Amniotic membrane products – There is some date to support that better results and faster recovery with less side effects if PRP or amniotic membrane products are used during acne scar treatments. There is a movement more towards amniotic/placental products and away from PRP because there are more growth factors/healing properties in these vs PRP.

LLLT – There is a plethora of studies to suggest that using low level laser light (LLLT) is beneficial to results and healing times. The most researched device is Healite, and this should be performed immediately following all acne scar procedures which use energy devices. It calms the skin and improves circulation.

Acne scarring procedures are continuing to improve as technology and techniques evolve. One must understand that results require months to fully appreciate and multiple treatments (3-5 or more) are often needed to optimize results. Expectations need to discussed with providers/patients so that all are on the same page as to what one can achieve with treatments.

Dr. Weiner is an Acne Scar Center of Excellence designated by Bellafill and is a specialist on acne scars. He is a lecturer and trainer for Bellafill. He has become one of the leading authorities on Radiofrequency Microneedling and travels the globe lecturing on this technology. He performed the FDA trails for the Genius. He recently authored a chapter on RF Microneedling which soon will be published in the Facial Plastic Clinics of North America. He also wrote a recent chapter on Radiofrequency Safety and Complications which will be part of a book titled “Complications in Minimally Invasive Facial Rejuvenation: Avoidance and Management” by Paul Carniol, MD

How to Minimize Risks of Vascular Occlusion and Blindness During Filler Injections

Dermal fillers improve volume loss or enhance facial features. Their use is increasing at rate of 10% or more per year worldwide. Adverse events are usually minor and consist of bruising, swelling, asymmetries, and nodularity. More significant complications are fortunately rare and include infection, granuloma, skin necrosis, and blindness. This blog will concentrate on techniques to minimize the risks of having a vascular event.

There are 2 ways a blood vessel can become occluded. If an artery is entered and filler is injected within the lumen (Intraluminal), filler will travel down the vessel until it gets lodged. At this point, the filler stops the flow of blood to areas which are dependant on this blood supply. Smaller pieces of the filler can break off and flow into areas far from the initial injection and into the very small arterioles. There are theories that an inflammatory response/cascade exacerbates the injury to the skin and dependent structures. This is Dr. Weiner’s opinion for the etiology of the majority of vascular occlusion cases.

A second way a vessel can occlude is if there is external compression of the vessel by filler. This is plausible in areas of compartmentalization, such as in the nasal tip. If the pressure within the nasal tip exceeds the pressure within an artery, flow will stop. Unfortunately in this area, vascularity is so poor that peripheral flow doesn’t occur. External compression is not a major problem in most areas of the face in Dr. Weiner’s opinion. Most vessels can be ligated during surgery and there is no resultant skin necrosis – proving that peripheral flow can make up for an externally compressed vessel.

The worst cases of vascular occlusion result in blindness. This is the result of a filler embolus that travels through an anastomosis between the external and internal carotid systems. The filler backs up into the central retinal artery which feeds the retina. Blood flow is blocked to the retina and blindness ensues.

In most cases, early recognition of a vascular event can be reversed with hyaluronidase if a hyaluronic acid filler was used. Minimal or no sequelae are seen if action is taken within the first 4-6 hours. Unfortunately, even immediate action for blindness related to a filler complication, has little or no success.

There have been about 100 reported cases of blindness from fillers, with most of the cases coming out of Asia. This is certainly underreported though. The areas of most risk for blindness are injections in: glabella, nose, periocular, and NLF. Fat is the most common filler causing blindness, but all fillers have been implicated. Any area of face is at risk for vascular occlusion/necrosis.

The key to avoiding vascular complications from fillers is implementing safe techniques and knowledge of the vascular anatomy. While there is a paucity of data to support this, Dr. Weiner believes that cannula injections are less risky than needles for a vascular event. Larger cannulas, 25g or larger, are less likely to enter a vessel than a needle. While there have been cases of vascular occlusion with cannulas, to the author’s knowledge, none have been reported with 23g or larger. The smaller the cannula, the closer it becomes to looking like a needle, and therefore the advantages are less. (Please read Dr. Weiner’s blog about cannulas to understand their advantages.)

Techniques for optimizing safety during dermal filler administration:

Know the major vascular structures and their landmarks
Avoid areas you (the injector) are not comfortable with. Particularly the high risk areas: glabella, nose, periocular
Consider using only reversible fillers if there is any concern regarding vascular occlusion or experience
Use cannulas whenever feasible, preferably 25/23g or larger
Avoid boluses, small linear threads are safer
Constantly move tip of cannula/needle. If more filler is needed in a particular area, revisit the area with another pass.
A NEGATIVE ASPIRATION DOESN’T EQUATE TO BEING EXTRAVASCULAR AND CAN GIVE A FALSE SENSE OF SAFETY
Injection onto periosteum is safest but does not guarantee a vascular free injection
Pressure on the supratrochlear vessels during glabellar or nasal injections might limit reflux of filler into the orbital vessels
Retrograde injections are safer than anterograde injections
Dermal injections should be relatively safe
Avoid deep injections in the lips. Stay superficial to the muscles
An injection that is perpendicular to a vessel is purported to be safer than one which is parallel because the time within the vessel should be less if it is entered
Have on hand 6-8 vials of Hylenex
Any unusual bruising, pain or visual change needs immediate evaluation

The bottom line is that complications can occur with dermal fillers, even during a routine procedure. Many measures can be taken to minimize the risks. Choosing an experienced injector will result in safer and better outcomes.

Dr. Steven F. Weiner is the #1 physician trainer for Galderma (Restylane, Silk, Lyft, Sculptra, Defyne, Refyne). He has been using cannulas since 2011 and is one of the most experience injectors in the US.

Dr. Steven F. Weiner’s 6 year Experience with Blunt Cannulas for Dermal Fillers

The value of volume replacement in the aging face is now universally recognized as one of the most beneficial procedures to restore youthfulness. The combination of sun exposure, aging, and genetics leads to collagen, fat, muscle, and bone loss. Reinflating the cheeks, lips, and tear troughs are routinely done by physicians across the world on a daily basis. Most of these patients will have a week or more of downtime – swelling, bruising, discomfort – but that doesn’t have to be. Blunt cannulas can minimize most of these side effects associated with filler injections and has become standard practice for Dr. Weiner for the past 6 years.

The benefits of blunt cannlas are:

There is only one insertion point to treat multiple areas. This equates to less intrusions through the skin and therefore a more comfortable procedure.
The tip is rounded and blunted. This very fact accounts for less bruising/swelling. When a blood vessel is encountered with the end of the cannula, the vessel is more likely to be gently displaced rather than punctured.
There is increased safety. A phenomenon termed “vascular occlusion” occurs when a filler is injected into a blood vessel. The filler then blocks the blood flow and can lead to necrosis (death of skin) or even blindness. It is much less likely to occur with blunt cannulas, particularly larger cannulas (23 or 25 guage), because they don’t enter blood vessels as easy as needles do.
Allows treatment in areas otherwise not easily accessible. Due to the safety of the cannulas, there are now areas of the face which are more easily treated. The superficial temporal area, supraorbital, forehead, piriform, periocular and lower eyelid are now routinely treated with cannulas whereas with needles, these areas were very precarious to inject.
Downtime is minimize. As a result of all the benefits listed above, most patients have significantly less healing time and are much happier after receiving their filler treatments with blunt “safety” cannulas.

If blunt cannulas have so much benefits, why are only 5% of the providers using them for dermal fillers? The art of using cannulas is not an easy one. Patience is required because directing the tip to the exact spot it is needed is not always easy. Remember, when the tip encounters an obstruction (vessel, ligament, collagen), it will need to traverse around it and not pierce it (as needles would do). This can be frustrating and lead to longer and less satisfactory results for the inexperienced cannula injector.

Dr. Weiner is one of the leading authorities on cannula injections of dermal fillers and has used them for over 6 years for nearly all of his injections. The cannulas provide a safe, comfortable, minimal downtime technique for volumizing the aging face, even with multiple syringes being used simultaneously.

The best way to get your lips augmented…Hyaluronic Acid Fillers using Blunt Cannulas

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Lip augmentation has received a lot of press over the past couple years and its been mostly bad. That’s because most physicians either overfill the lips or don’t understand what makes lips attractive and natural appearing. In addition, most patients equate lip augmentation to severe pain and several days of downtime with bruising and swelling. I would like to try to convince the public that you don’t have to fear the process of plumping up your lips and don’t have to have days of downtime where you either are hiding in you house or explaining to people that your significant other didn’t beat you.

Blunt cannulas have changed the game for lip augmentation. Through one entry port (which requires a small needle poke) on each side, you can have both upper and lower lips filled with little or no bruising. After applying topical numbing creams to the lips for about 10 minutes, the procedure is very well tolerated. The other advantage is that the swelling is minimized because the lips are minimally traumatized. Many patients go straight out to lunch or drinks or back to work without being self-conscious of people looking at them. On the contrary, traditional lip augmentation using needles requires 4-5 penetrations (each time causing discomfort and risking bruising) per quadrant (so you have to multiply by 4). The blunt cannulas push vessels out of the way with their rounded tips so bruising is minimized. Also, most of the pain is in the surface penetration and once under the surface, the blunt cannulas give less discomfort.

Dental blocks are performed by many of my colleagues. I’m critical of this technique because:

Dental blocks are not comfortable
Often times the block is incomplete so there is still discomfort during the lip injection.
You often stay numb of a prolonged period of time with the associated drooling, etc.
The lip anatomy can be distorted with the block making precise lip enhancement difficult.

Some doctors are critical of using cannulas for the lips because they say the control of placement of the filler is less than when using the needle. Admittedly, there is less precision for the novice, but over time, I’ve become very efficient at using cannulas and there is little difference as far as results. Sometimes, after filling the lips with the cannulas, I will go back into the already numb lip and place minute amounts of filler along the vermilion border or in the tubercles with the needle technique. This usually does not cause significant bruising or swelling.

A natural set of lips is about 33-40% upper lip and 60-66% lower lip. Often doctors will make the lips the same size or the upper lip bigger and this looks very abnormal. Sometimes when the doctor is trying to improve the upper lip lines, this problem occurs by accident. The best way to correct the upper lips lines is to place filler in the area between the lips and nasal area with the cannulas in a horizontal fashion. This usually doesn’t affect the ratio described above. There is loss of bone in the upper jaw as well as loss of fat, and this injection technique replaces those tissue losses and improves the lines. (For more the most severe lines, I will use Belotero into these lines but this is with a needle and does lead to bruising in most cases.) Also, the lip is not supposed to go all the way to the corners. It should gradually taper off on the sides. Those people who get there lips injected evenly all the way across end up with “sausage lips”. Another error is placing too much filler in someones lips. Small lips can only be enhanced to a certain degree before they appear awkward and you look like a “trout mouth”. People with extraordinarily small lips are gradually made larger in my office. Over successive fills, they are slightly larger than their previous treatment. That way you avoid the lips which get through the doorway before the body.

Procedures which should be avoided at all costs, in my opinion are: permanent filler/ implants in the lips or the Valentine lip lift. These lead to abnormal lip appearance, unnatural mobility/movement, long-term complications (firmness, bumps) and unhappy patients. Some patients are trying to avoid repeated injections due to discomfort and resort to these solutions. Don’t do it!! Cannulas offer a more comfortable injection, and overtime, there is collagen stimulation which lengthens the times between treatments. My long-term lip augmentation patients get filled every 9-12 months.

In summary, lip augmentation doesn’t have to prolonged downtime, be considered intensely painful, and look unnatural. Blunt cannulas in the right hands can make for a much more pleasant experience. It’s important to seek out a physician who knows the anatomy of aesthetically pleasing lips and what is needed to achieve those results. Although bruising can occur with cannulas, it usually is minimal or nonexistent, and you can continue your active social schedule after the procedure.

Dr. Steven Weiner is a Board Certified Facial Plastic Surgeon practicing in Santa Rosa Beach, Florida, between Destin and Panama City Beach, Florida. After laying down his scalpel in 2005 he has devoted his practice to Lasers and Injectables.

Blog: http://stevenfweinermd.wordpress.com/

YouTube: http://www.youtube.com/user/StevenFWeinerFacial

Website: http://www.theclinique.net