A safe doppler ultrasound-guided method for nasolabial fold correction with hyaluronic acid filler.
Won-Lee, MD, PhD; Ji-Soo Kim, MD, MS: Hyoung-Jin Moon, MD; Eun-Jung Yang, MD, PhD
Aesthetic Surgery Journal 2021, Vol 41(6) NP486-NP492
Will ultrasound visualisation of the facial artery help to reduce the incidence of accidental intra-arterial injection of dermal filler product during nasolabial fold correction?
Dermal filler producers are a common non-surgical option for many people to address their concerns, as it is often quick to perform and has immediate results.
Serious complications have been noted following accidental damaged blood vessels during the procedure and are due to vessel occlusion or embolism of product. These can result in blindness and tissue necrosis, both of which have devastating consequences for the patient.
Often the most effective way to treat the nasolabial fold with dermal filler is to place the filler in multiple different layers from supraperiosteal to subdermal. The facial artery runs alongside the nasolabial fold; however, it has many different anatomical variations, which makes it more difficult to reliably avoid intra-arterial injection.
There have been several studies suggesting methods to reduce complications such as blindness following dermal filler treatments, and research into the anatomy of the facial artery, however no studies could be found where the treatment was modified depending on the anatomy of the patient.
These studies were commonly opinion-based and lacking in robust scientific research.
The authors wanted to investigate the position and course of the facial artery in patients undergoing nasolabial fold treatment using ultrasound as a way of improving safety of this procedure.
The study was performed in South Korea by a group of plastic surgeons, aesthetic surgeons, and a professor of plastic and reconstructive surgery.
Treatments were performed on patients between June 2018 and May 2019.
- Single centre, retrospective case series study
- Conducted in accordance with the Declaration of Helsinki.
- Ethical approval was given by the ethics committee of Hanyang University Seoul Hospital.
- Patients provided written informed consent for the publication of images.
50 patients were identified for this study.
- Patients with visibly moderate to severe nasolabial fold and the desire to correct them with hyaluronic acid dermal filler injection
- Patients who agreed to provide informed consent for ultrasound evaluation to identify the facial artery
- Patients whose follow up data was available
- Patients with incomplete follow up data (n=2)
- Patients with history of other surgeries e.g., silicone implants at the nasolabial fold (n=1) and history of nasolabial fold filler treatment within the previous 18 months (n=7)
This left 40 patients for evaluation in this study.
There were 2 men and 38 women with mean age 46.5 years (range 28-72 years).
2-dimensional Doppler ultrasound was used for each patient, resulting in 80 nasolabial fold assessments from 40 patients.
- Probe was placed along the nasolabial fold
- Probe was placed horizontally just underneath the nasal ala
The area for treatment was determined as 0.5cm medial and 0.5cm lateral to the nasolabial fold.
The position of the facial artery was documented as lateral, central, or medial in relation to the nasolabial fold treatment area.
The depth of the facial artery was assessed as being in the:
- Subdermal layer (superficial)
- Subcutaneous layer
- Muscular layer
- Submuscular layer (deep) – deep medial buccal fat layer or periosteal layer.
Placement of the dermal filler product depended on the location of the facial artery.
Hyaluronic acid dermal filler (Yvoire Volume Plus Filler, LG Chem) was used for deeper injections into the subcutaneous and submuscular layer using linear threads with a 22G cannula.
Hyaluronic acid dermal filler (Yvoire Classic Plus Filler, LG Chem) was used for superficial injections into the subdermal layer.
Patients whose facial artery was located outside the nasolabial fold area (see above) were treated with dermal filler injections into the subcutaneous and submuscular layers.
The patients’ vital signs were recorded throughout the course of the study, and they were observed for adverse events as noted by the investigator or reported by the patient.
Adverse events were classified according to the severity, seriousness and in relation to the treatment.
Post-procedural complications, lasting less than two weeks were:
- Vascular occlusion
Delayed hypersensitivity was defined as a swelling occurring more than three weeks after the treatment that necessitated intervention.
Mild injection-related side effects were not included in the list of the adverse events.
To assess the efficacy of the treatment itself, photographs of each patient were taken before, two weeks and 3 months after the treatment. Two physicians independently evaluated these photographs according to the wrinkle severity rating scale (WSRS) and graded as 1 (absent) to 5 (extreme).
WSRS scores underwent statistical analysis with SAS version 9.4.
Qualitative data were presented descriptively.
The facial artery was detected:
- 31% lateral to the nasolabial fold in 25 out of 80 cases
- 69% beneath the nasolabial fold in 55 out of 80 cases
Of those beneath the nasolabial fold, the facial artery was located in the:
- 18% subdermal layer in 10 out of 55 cases
- 42% subcutaneous layer in 23 out of 55 cases
- 35% muscular layer in 19 out of 55 cases
- 5% deep medial buccal fat layer in 2 out of 55 cases
- 5% periosteal layer in 1 out of 55 cases
No patients experienced severe vascular complications.
Adverse events were described as mild to moderate, with bruising being the most common side effect reported (3 cases).
The mean baseline WSRS score was 3.68 (with a Standard deviation of 0.76).
At two weeks the mean score was 2.03 (with a Standard deviation of 0.80).
At three months the mean score was 2.28 (with a Standard deviation of 0.78).
The reduction in scores remained statistically significant at two weeks, and three months post-treatment (p<0.001).
No proven association between WSRS score and facial artery location.
The fact that almost a third of facial arteries we not detected in the nasolabial fold area suggests that anatomical knowledge alone is not sufficient to guarantee the prevention of vascular occlusion.
Depth as well as lateral positioning of the facial artery is important to determine, however the authors comment on the fact that depth alone is an unreliable measure, as this can change with physical compression of the skin with the ultrasound probe. Instead, anatomical layer in which the facial artery runs should be noted.
Strengths of the Study
The study was conducted with ethical approval.
No financial interest was declared.
No conflict of interest was declared, although one of the authors is an investigator, speaker and consultant for LG Chem, whose filler products were used, this was not relevant in the context of this study, as the study was not investigating the filler product itself.
Independent statistical analysis was performed on the quantitative data provided from the Wrinkle Severity Rating Scale.
Weaknesses of the Study
Small sample size.
The recommendation for Doppler ultrasound use will require a lot of training for practitioners. The equipment is also expensive, and so while it may be useful, this study does not necessarily have real world applications.
Doppler ultrasound cannot detect smaller arteries or vessels; therefore, ultrasound cannot remove risk of intra-arterial injection completely.
Doppler ultrasound can be a particularly useful adjunct to guide treatment and reduce the risk of inadvertent intra-vascular injection.
Identification of the facial artery depth and position can inform the practitioner which product, technique, and layer to treat the nasolabial fold, allowing for the safest yet aesthetically effective treatment for the patient.