Usefulness of Doppler sonography in aesthetic medicine

The temporal fossa is a common site of aesthetic interventions. Temporal fat pad and muscles undergo atrophy with age, which is considered one of the worst signs of aging by aesthetes. Aesthetic medicine enables augmenting these defects with injectable fillers. In order to ensure safety, temporal anatomical structures, the superficial temporal artery in particular (precisely its frontal branch), should be considered. It is a standard practice to determine the safe point for puncture empirically by measuring the appropriate distance from the zygomatic arch. Unfortunately, a vessel course other than standard one is possible. Therefore, we propose a more precise solution involving an accurate determination of the course of these vessels using Doppler ultrasound. Determination of the course of the frontal branch of the temporal artery using ultrasound poses no difficulty. It may be visualized through longitudinal application of a linear transducer 1–2 cm from the hairline⁽⁷⁾.

In the case of interventions in the area of the tear trough and nasolabial folds, attention should be paid to the synonymous angular vessels and the infraorbital arteries. The angular artery, which is an extension and the terminal part of the facial artery, runs together with a synonymous vein along the lateral edge of the nose, giving off small facial branches and connecting to the dorsal nasal artery in the medial angle of eye⁽⁸⁾. The infraorbital artery, a strong branch of the maxillary artery, runs through the inferior orbital fissure anteriorly, passing through the infraorbital groove and canal. The infraorbital foramen is palpable 1 cm under the inferior orbital edge in the pupil axis. There is intersubject variation in the position of the foramen, with its distance from the edge of the orbit ranging between 6.9 and 10.9 mm. We presented flow disturbances in angular vessels based on clinical cases.

The dorsal nasal artery, which is the second terminal branch of the ophthalmic artery, runs caudally from the frontal foramen to join the angular artery on the lateral nasal edge. It supplies the dorsal and lateral parts of the nose. A 43-year-old patient developed reddening and progressive bruising of the nasal and frontal region 5 hours after HA injection into the ridge and bridge of the nose. The woman reported for a medical appointment. She received 1,300 units of hyaluronidase. Also, vitamin C, dexamethason, ciprofloxacin and massage were included. The appearance of the skin improved and a follow-up ultrasound was recommended. No HA deposits were detected on ultrasound, indicating their effective dissolution. The flow in the dorsal nasal arteries was maintained.

Inferior and superior labial arteries and veins are the most important homonymous vessels of the mouth region. Both arteries usually branch off around the same region near the corner of the mouth. The inferior labial artery courses transversely and medially in the lower lip and the orbicularis oris muscle to join the contralateral artery. An analogous course is seen for the superior labial artery in the upper lip.

Compression and, consequently, embolism of the labial arteries caused by accumulation of filler deposit in the region of the vessels, is a possible complication in this facial area. We presented a case of a 43-year-old woman after lip augmentation with HA filler. After the procedure, the patient reported dry lips (the lips were wrinkled with palpable lumps) with edema persisting for 4 months. After edema resolution, no satisfactory aesthetic effect was obtained.

Injecting fillers is an effective method of hand rejuvenation. However, it should be remembered that an extensive network of veins surrounded by a thin layer of subcutaneous tissue is located between the skin and the superficial dorsal fascia⁽⁸⁾. Safe injection points are located in the spaces between the tendons, distally to the wrist⁽⁹⁾. In the case of hands, the injection technique (a needle with a blunt tip and injection of small volumes are recommended) is important as the delicate vascular network can be easily damaged, which may result in injecting the preparation into a vessel, and thus causing complications. We included two patients with absent blood flow in Doppler ultrasound in our study.

We presented vascular complications secondary to aesthetic interventions involving filler injection. Addressing this issue is of particular importance as the number of augmentation procedures is constantly increasing, which translates into an increased incidence of complications. Furthermore, aesthetic medicine is a very young field lacking its own diagnostic methods that would allow for a reliable skin diagnosis to avoid or, if needed, treat potential complications. This gap may be filled by ultrasonography, whose advantages and possibilities have already been confirmed. The latest world literature shows that Doppler-assisted identification of facial blood vessels and assessment of flow patterns have gained an increasing importance. Unfortunately, Doppler options are not available in dermal ultrasound scanners equipped in high-frequency (30–70) MHz transducers. Therefore, classic premium class ultrasound scanners, which may be featured with Doppler options and 15–22 MHz transducers are currently used for the assessment of facial vasculature. The use of these devices allows for the imaging of small vessels within the face, located a few millimeters from the epidermis surface. The facial artery, which ends with the angular artery, is one of the most important facial vessels that can be damaged due to common administration of fillers into the nasolabial folds. Its course within the nasolabial folds is varied. However, as shown by Lee et al., it is possible to identify these arteries with Doppler ultrasound, which facilitates proper filler administration, i.e. bypassing the artery⁽¹⁰⁾. Iwayama et al.⁽¹¹⁾ compared filler administration into the nasolabial folds using a conventional method with a cannula vs ultrasound-guided identification of vessels and cannula monitoring. The authors also used both methods to assess blood supply to the skin before and after the procedure. They showed that it is much easier to bypass a blood vessel by monitoring the position of the cannulas in relation to the vessels using an ultrasound image. At the same time, they showed that in both cases the blood supply to the skin was reduced after the filler was administered; however, there were smaller changes in the area where the filler was administered with simultaneous ultrasound-assisted monitoring of cannulas⁽¹²⁾. A similar variance may be seen in the course of the supratrochlear artery, which may be located using Doppler ultrasound. This allows for safe correction of forehead wrinkles with fillers⁽¹²⁾. It is very important to identify the supratrochlear artery and the supraorbital artery before injecting fillers into the forehead as these are branches of the ophthalmic artery, as shown by Tansatit et al.⁽¹³⁾. Therefore, accidental injection of the preparation into these arteries during procedure may cause embolization of the ophthalmic artery and blindness⁽¹³⁾. As reported by Phumyoo et al., Doppler ultrasound allows visualization of arteries with a diameter ≥ 0.3 mm. However, the authors used a linear transducer with a frequency of up to 12 MHz⁽¹⁴⁾. It seems that the use of a transducer with a higher frequency (18–22 MHz) allows for visualization of vessels with a diameter of about 0.1 mm. Therefore, it should be possible to visualize the supratrochlear or the supraorbital artery, whose mean diameters are 0.71 mm and 0.8 mm ± 0.38 mm, respectively, using such transducers⁽¹³⁾.

Visualization of needles or cannulas also should pose no difficulty in most cases. Furthermore, it was shown in the world literature that ultrasonography may be used to detect the injected filler deposits^(1,4). Therefore, ultrasonography is also useful in the treatment of vascular complications after injection of tissue fillers. It allows for localization of a filler deposit responsible for arterial compression. Then, it provides guidance for accurate needle introduction and injection of hyaluronidase to dissolve the deposit⁽¹⁵⁾. Doppler options allow for a simultaneous assessment of positive outcomes of the intervention used, i.e. restored blood flow in a previously compressed vessel⁽¹⁶⁾.